JERG-0-039D(E)General

STANDARD FOR SOLDERINGPROCESS FOR SPACE USE

Mar. 29, 2022

Japan Aerospace Exploration Agency

JERG-0-039D(E)This is an English translation of JERG-0-039D and does not constitute itself.
Whenever this document conflicts with the original document in Japanese, the original
document takes precedence.
Disclaimer
The information contained herein is for general informational purposes only.
JAXA makes no warranty, express or implied, including as to the accuracy, usefulness
or timeliness of any information herein.
JAXA will not be liable for any losses relating to the use of the information.

Published by
Japan Aerospace Exploration Agency
Safety and Mission Assurance Department
2-1-1 Sengen Tsukuba-shi, Ibaraki 305-8505, Japan

JERG-0-039D(E)TABLE OF CONTENTS

GENERAL ........................................................................................................................................ 1
1.1

Purpose ........................................................................................................................................... 1

1.2

Scope ............................................................................................................................................... 1

1.2.1

Type of development model, development model definition .................................................... 1

1.2.2

Foreign products ......................................................................................................................... 2

1.3

Supplement .................................................................................................................................... 2
RELATED DOCUMENTS ............................................................................................................. 4

2.1

Applicable documents .................................................................................................................... 4

2.2

Reference documents ..................................................................................................................... 4
TERMS AND DEFINITIONS ....................................................................................................... 5
GENERAL REQUIREMENTS ...................................................................................................... 6

4.1

General ........................................................................................................................................... 6

4.2

Training and certification ............................................................................................................. 6

4.2.1 General ........................................................................................................................................ 6
4.2.2

Vision requirements ................................................................................................................... 7

4.2.3

Recertification ............................................................................................................................. 7

4.2.4 Revocation of certified status ..................................................................................................... 7
4.3

Design conditions......................................................................................................................... 10

4. 4

Process certification tests .......................................................................................................... 10

4.4.1

Process certification tests (I) .................................................................................................... 11

4.4.2

Process certification test (II) .................................................................................................... 11

4.5

Manufacturing condisions ........................................................................................................... 12

4.5.1

Manufacturing environment .................................................................................................... 12

4.5.2

In-progress storage and handling ........................................................................................ 13

4.5.3

Electrostatic discharge control ................................................................................................ 13

4.6

Quality assurance ........................................................................................................................ 14
DETAILED REQUIREMENTS ................................................................................................... 15

5.1

Tools and equipment ................................................................................................................... 15

5.1.1

Tools and equipment control ................................................................................................... 15

5.1.2

Soldering tools and equipment ................................................................................................ 15

5.1.3

Conductor preparation tool ...................................................................................................... 16ii

JERG-0-039D(E)5.1.4

Thermal shunts ........................................................................................................................ 20

5.1.5

Inspection optics ....................................................................................................................... 20

5.2

Materials ...................................................................................................................................... 20

5.2.1

Solder......................................................................................................................................... 20

5.2.2

Liquid flux ................................................................................................................................. 21

5.2.3

Solvents and cleaners ............................................................................................................... 22

5.2.4

Requirements for conductors to be soldered ........................................................................... 23

5.3

Preparation for soldering ............................................................................................................ 25

5.3.1

Parts and materials inspection ................................................................................................ 25

5.3.2

Tools inspection ........................................................................................................................ 26

5.3.3

Wire preparation ...................................................................................................................... 27

5.3.4

Gold plating removal ................................................................................................................ 27

5.3.5

Tinning ...................................................................................................................................... 28

5.3.6

Solder pot control ...................................................................................................................... 28

5.4

Parts mounting ............................................................................................................................ 31

5.4.1

General ...................................................................................................................................... 31

5.4.2

Lead cutting and bending ........................................................................................................ 33

5.4.3

Mounting terminals .................................................................................................................. 36

5.4.4

Mounting of parts to terminals ................................................................................................ 39

5.4.5

Mounting leads and parts to PWBs ......................................................................................... 40

5.5

Attaching conductors to terminals ............................................................................................. 49

5.5.1

General ...................................................................................................................................... 49

5.5.2

Turret and straight pin terminals ........................................................................................... 51

5.5.3

Bifurcated terminals ................................................................................................................ 53

5.5.4

Hook terminals ......................................................................................................................... 56

5.5.5

Pierced terminals...................................................................................................................... 56

5.5.6

Solder cups (connector type) .................................................................................................... 57

5.5.7

Solder cups (swaged type) ........................................................................................................ 57

5.5.8

Insulation sleeving application ................................................................................................ 58

5.6

Hand soldering............................................................................................................................. 58

5.6.1

General ...................................................................................................................................... 58

5.6.2

Heat application ....................................................................................................................... 59

5.6.3

Solder application ..................................................................................................................... 60

5.6.4

Solder cleaning (after hand soldering) .................................................................................... 64

5.6.5

Rewor......................................................................................................................................... 64

5.7

Wave soldering............................................................................................................................. 65

5.7.1

Wave soldering process control ................................................................................................ 65iii

JERG-0-039D(E)5.7.2

Materials ................................................................................................................................... 65

5.7.3

Preparation and assembly ....................................................................................................... 66

5.7.4

Process condition settings ........................................................................................................ 66

5.7.5

Solder cleaning (after wave soldering) .................................................................................... 67

5.7.6

Rework ...................................................................................................................................... 68

5.8

Quality assurance ........................................................................................................................ 68

5.8.1

Document control...................................................................................................................... 68

5.8.2

Records ...................................................................................................................................... 68

5.8.3

Verification of tools, equipment, and materials ..................................................................... 69

5.8.4

Inspection .................................................................................................................................. 69

NOTES ........................................................................................................................................... 72
Appendix I Terms and definitions ................................................................................................... I-1
Appendix II Samples of solder joints ............................................................................................ II-7

iv

JERG-0-039D(E)LIST OF FIGURES
Figure 1-1

Soldered parts mounting method plan and checklist form ............................................ 3

Figure 4-1

Typical certification record sheet (1/2)............................................................................. 8

Figure 5-1

Typical soldering gun (Prohibited) ................................................................................. 15

Figure 5-2

Typical use of lead cutting nippers ................................................................................ 17

Figure 5-3

Typical stripper ............................................................................................................... 19

Figure 5-4

Distance from to the part body to the start of the bend in a lead ................................ 35

Figure 5-5

Terminal mounting by elliptical funnel type swage ..................................................... 37

Figure 5-6

Roll flange terminal ........................................................................................................ 38

Figure 5-7

Terminal mounting by V-funnel swage ......................................................................... 38

Figure 5-8

Terminal damage ............................................................................................................ 38

Figure 5-9

Stress relief example ....................................................................................................... 39

Figure 5-10

Mo unting ho le o bstruction .................................................................................. 40

Figure 5-11

Horizontal mount .......................................................................................................... 41

Figure 5-12

Vertical mount ............................................................................................................... 41

Figure 5-13

Stress relief part termination ....................................................................................... 42

Figure 5-14

Bend angle ..................................................................................................................... 42

Figure 5-15

Conductors terminating on both sides ......................................................................... 43

Figure 5-16

Lapped lead height above board................................................................................... 44

Figure 5-17

Lapped round termination............................................................................................ 45

Figure 5-18

Lapped ribbon lead........................................................................................................ 46

Figure 5-19

Clinched termination .................................................................................................... 47

Figure 5-20

Lead bend ...................................................................................................................... 47

Figure 5-21

Straight-through termination ...................................................................................... 48

Figure 5-22

Straight-through lead retention ................................................................................... 48

Figure 5-23

Attachment to wire harness terminals ........................................................................ 49

Figure 5-24

Wrap orientationn ......................................................................................................... 50

Figure 5-25

Conductor wrap ............................................................................................................. 51

Figure 5-26

Turret terminal ............................................................................................................. 52

Figure 5-27

Continuous run wrapping - turret terminals .............................................................. 53

Figure 5-28

Bottom route connections to bifurcated terminals ...................................................... 54

Figure 5-29

Side route connections to bifurcated terminals ........................................................... 54

Figure 5-30

Lead wrap ...................................................................................................................... 55

Figure 5-31

Continuous run wrapping/bifurcated terminals ......................................................... 55

Figure 5-32

Continious run wrapping /bifurcated terminals alternate procedure ....................... 55

Figure 5-33

Connections to hook terminals ..................................................................................... 56v

JERG-0-039D(E)Figure 5-34

Connection to pierced terminals .................................................................................. 56

Figure 5-35

Connections to solder cups (connector type) ................................................................ 57

Figure 5-36

Connection to solder cups (swaged type) ..................................................................... 57

Figure 5-37

Soldering of electrical wire and lead to contact .......................................................... 61

Figure 5-38

Solder-ball termination ................................................................................................. 62

Figure 5-39

Heel fillet ....................................................................................................................... 63

Figure 5-40

Round lead terminations .............................................................................................. 64

LIST OF TABLES
Table 5-1 Solder contaminant levels maximum allowable percent by weight of contaminant ....... 29
Table 5-2 Necessity of touch-up of peeled solder resist ..................................................................... 72vi

JERG-0-039D(E)GENERAL
1.1 Purpose
This standard describes the requirements for high reliability electrical connection soldering
applicable to launch vehicles and spacecrafts.
1.2 Scope(1) This standard describes the requirements for hand and wave soldering to obtain reliable
electrical connections.
(2) This standard shall apply to cases prescribed in the contractual specifications. In such acase, this standard shall apply to both the supplier and their subcontractors responsible for
performing parts of the contract.
(3) This standard shall not apply to internal solder joints of parts. Soldering for surface
mounting, including chip parts reflow soldering, shall be as per JERG-0-043.
(4) If prescribed in the specifications and unless otherwise instructed, this standard shallapply, according to the classification of newly developed articles, to the range of articles as
per Paragraph 1.2.1.
(5) In case of any discrepancy or inconsistency between the requirements herein and thosein the contractual specifications, the latter shall take precedence.
(6) In case of any discrepancy or inconsistency between the requirements herein and thosein other technical standards, consultation shall be held with the competent inspector of theJapan Aerospace Exploration Agency (hereafter the “JAXA”).
(7) For BGA/CGA, refer to JERG-0-054.
1.2.1 Type of development model, development model definition
Designing, prototyping and manufacturing of new launch vehicles and spacecrafts shall beclassified as follows:(1) Development model
The application of this standard to development models shall be optional. If environmental
or life testing is required, however, this standard shall apply.
(2) Flight equivalent modelThis standard shall apply to flight equivalent models.
(3) Repair and spare parts
This standard shall apply to repair and spare parts.

1

JERG-0-039D(E)1.2.2 Foreign productRegardless of the provisions in Paragraph 1.2.1, the following documents shall apply in lieu of
this standard to foreign devices that are designed, prototyped, manufactured, or modified
abroad for installation into launch vehicles and spacecrafts and hence are unsuitable for theapplication of this standard.
a.

J-STD-001*S "Space Applications Electronic Hardware Addendum to IPC J-STD001* Requirements for Soldered Electrical and Electronic Assemblies"b.

ECSS-Q-ST-70-08C "Manual soldering of high-reliability electrical connections"

Note that * indicates the latest version.
1.3 Supplement(1) Review of soldering process
Using the form shown in Figure 1-1, the supplier shall prepare and submit to JAXA for
review a summary of the recertification training for the soldering process, the certification
testing therefore, and the Soldered-Parts Mounting Method Plan and Checklist, which
incorporates considerations including at least items (a) to (c) listed below. The review shallbe conducted as part of Preliminary Design Review and Critical Design Review.
a. New aspects of the process and the impact thereof on important quality characteristics
b. Extent of constraints on functional and performance verification during the testing andinspection processes
c. Frequency of nonconformance of comparable articles in the past(2) Incorporation of review results
The supplier shall incorporate the review results regarding the application of this standard
into

the

materials(drawings,

manufacturing

process

specifications,procedures,

administrative rules, etc.) relevant to the implementation items (design standardization,engineering

documentation,

shop

floor

control)ofthequality,reliability,orsafety/development assurance program plan.
(3) Product verification
The supplier shall plan and verify, with the help of manufacturing engineers, initial-lot
products to which the review results are applied, products normally commerciallyunavailable, and mission-critical products.

2

Soldered Parts Mounting Method Plan and Checklist
Soldering typeParts shapes
orAs-assembled Mounting method
configuration
thereof

StakingSpecifications

methodof PWB, etc.

Necessity ofHand soldering: H manufacturing * Necessity ofengineer’s
recertification
Wave soldering: W
witnessing
Reflow soldering: R

Necessity of
Remarks:
process
Reasons andcertification supplementary
testcomments-3JERG-0-039D(E)* Indicate “Required” when required to adopt a new process with no history of previous application to spacecraft or when any change
has been made to the content of the certification.
Other special issues:
Figure 1-1 Soldered parts mounting method plan and checklist form

JERG-0-039D(E)RELATED DOCUMENTS
The related documents are as follows. Disclosure of some mechanistic documents andmaterials may be restricted.
2.1 Applicable documents
The documents listed below form a part of this standard to the extent specified herein.
Unless otherwise specified, their latest versions at the time of application of thisstandard shall be used.
(1) JAXA standards
a. JERG-0-040: Standard for Electronic Bonding Process for Space Useb. JERG-0-041: Standard for Electrical Wiring Process for Space Usec. JERG-0-042: Standard for Printed Wiring Boards and Assemblies for Space Used. JERG-0-043: Standard for Surface Mount Soldering Process for Space Use
e. JERG-0-054: Standard for BGA/CGA Mounting Process for Space Use(2) Public standards
IPC standard
a. J-STD-004: Requirements for Soldering Fluxes
b. J-STD-006: Requirements for Electronic Grade Solder Alloys and Fluxed andNon-Fluxed Solid Solders for Electronic Soldering Applications
JIS standard
c. JIS Z 3282: Soft Solders—Chemical Compositions and forms
2.2 Reference documents
The following documents provide information supplementary to the contents of thisstandard:
JIS standard
a. JIS K 3282: Soft Solders—Chemical Compositions and forms
MIL standard
a. MIL-STD-1276: Leads for Electronic Component Parts
ASTM standards
a. ASTM B 488: Electrodeposited Coatings of Gold for Engineering Uses
b. ASTM B 545: Standard Specification for Electrodeposited Coatings of Tinc. ASTM B 700: Standard Specification for Electrodeposited Coating of Silver forEngineering Use
AMS standards

4

JERG-0-039D(E)a. AMS 2418: Plating Copper
b. AMS 2422: Plating, Gold
SAE-AMS (Aerospace Material Specification)
a. SAE-AMS-P-81728: Plating, Tin-Lead (Electrodeposited)b. SAE-AMS-QQ-N-290: Nickel Plating (Electrodeposited)
JAXA document
a. JERG-0-039-TM001 Collection of Technical Data of Standard for Soldering
Process for Space Use (JERG-0-039)
IPC standard
a. J-STD-001*S: Space Applications Electronic Hardware Addendum to J -STD001*

Requirements for Soldered Electrical and Electronic

Assemblies
Note that * indicates the latest version.
ESA standard
a. ECSS-Q-ST-70-08C: Manual soldering of high-reliability electrical connections
TERMS AND DEFINITIONS
Reference shall be made to Appendix I for the terms and definitions used in thisstandard.

5

JERG-0-039D(E)GENERAL REQUIREMENTS
4.1 GeneralThe

suppliershall

preparedocuments,

includingdesignstandards,

process

specifications, work procedures, and inspection procedures, all conforming with therequirements herein, and shall perform application and control accordingly.
4.2 Training and certification
4.2.1 General(1) Engineers in charge of mounting design for electronic devices (including Printed
Wiring Board (PWB) pattern design) shall be highly knowledgeable of therequirements herein.
(2) The supplier shall be responsible for establishing and operating a training andcertification system that is intended for operators and inspectors involved in solder
mounting and is compliant with the requirements herein.
(3) The supplier shall ensure that soldering instructors (or manufacturing engineers)
will provide work instructions on difficult soldering tasks and check work results.
Soldering instructors shall preferably be certified for soldering and related skills b y
external organizations.
(4) Training shall be provided regarding electronic device soldering -related skills,
techniques, equipment operation, and procedures. Records shall be retained of suchtraining.
(5) Operators and inspectors shall be tested and certified to have the sufficientknowledge and skills required for the specified soldering.
(6) The certification shall be pertinent to typical soldering techniques used for the
product.
(7) When operators are certified with restrictions (type of soldering on PWBs and/or
terminals, cable termination, compulsory use of spectacles), it shall be explicitly
stated on the certification record that contains their test performance. Figure 4 -1
shows reference for a typical certification record sheet.
(8) Certification records shall be presented immediately upon request by the JAXA’s
inspector or similarly authorized personnel.
(9) The records relating to education and training shall be retained as quality record
for a fixed period of time.
(10) The training and certification program shall use actual samples, drawings, or
photographs of acceptable solders. Any drawings and photographs contained herein
may be used for supplementary information. Actual samples, drawings, or
photographs of unacceptable solders may be used for clarification or comparison.

6

JERG-0-039D(E)4.2.2

Vision requirements

Operators and inspectors shall, at the time of the initial certification or recertification,
have their vision testing checked by a qualified medical doctor or personnel under
his/her supervision. Alternatively, the vision testing may be administered by thecertification examiner.
(1) Near vision
Operators shall meet one of the following requirements with uncorrected or correctedvision per eye or both eyes, or shall have equivalent vision.
a) Read the Jaeger #1 from 36cm (14inches) away.
b) Distinguish the target at 1.0 in the Landolt ring near vision testing chart (30cm)
from 30cm away from the target.
c) Distinguish the target at 0.8 in the Landolt ring near vision testing chart (30cm)
from 40cm away from the target.
(2) Color vision
Ability to distinguish colors required for practical reasons .
4.2.3 Recertification
Recertification of operators and inspectors shall be required when any one of the four
conditions below applies. The recertification procedures shall include sufficienttraining or retraining appropriate for the work assigned to the operators or inspectors .
(1) Proficiency requirements herein are not met.
(2) New techniques have been approved that requires different skills.
(3) Work period interruption of greater than six (6) months occurs.
(4) The validity period of certification (two (2) years at longest) is exceeded.
4.2.4 Revocation of certified status
Certification shall be revoked when:(1) Certificate holder fails recertification.
(2) Certificate holder fails to meet visual acuity requirements of Paragraph 4.2.2.
(3) Employment is terminated.

7

JERG-0-039D(E)ABC Co., Ltd.
Certification Record of High Reliability Hand Soldering and Related Work
Name

Taro Handa

Manufacturing Dept.,

Dept./Sect.

Section 1

Use a new sheet for
Date of May 10,
testing 1991

Vision test

Visionrecertification

WorkingPass

conditions

Fail

Uncorrected/
Corrected

2020/4/23
Scope of certification

Performance

Process Spec

A

B

Note

Fail

a. Soldering to terminals
1) Turret terminals

SOP-S-02✓

May 10, 1991

2) Bifurcated terminal

Ditto

✓

Ditto

3) Hook terminal

Ditto

✓

Ditto

4) Solder cups

Ditto

✓

Ditto

5) Pierced terminals

Ditto

✓

Ditto

SOP-S-03✓

May 11,1993:

6) Special purpose terminals

Recertified
b. Soldering on printed wiring boardsi) Straight-through lead

SOP-S-01✓

May 10, 1991

terminationsii) Lapped lead terminations

Dittoiii) Clinched lead terminaitons

Ditto

c. Solder sleeve

SOP-S-04✓

d. Ferrule soldering

SOP-S-05✓

e. Chip parts soldering

SOP-S-06

f. Semi-rigid cable soldering

SOP-S-07

Feb. 20, 1992:
Recertified
Oct. 10, 1993:
Recertified

Rework techniqueg. Wicking method
Writtentest
results

92
Points

SOP-R-01
Final judgment

Pass
May 10, 1991✓
Judged bySpecial remarks on certification/recertification results

Figure 4-1 Typical certification record sheet (1/2)

8

TanakaJERG-0-039D(E)Vision test results
Apr. 23, 1991: Pass, uncorrected vision
Apr. 25, 1992: Pass, uncorrected vision
Apr. 10, 1993: Pass, corrected vision

Special remarks on certification/recertification results
Feb. 20, 1992

Skills training per process specifications Judged by Tanaka(LP2111: Newly created)
Jun. 2, 1993

Skills training per process specifications Judged by Tanaka(LP2111: Newly created)
Oct. 10, 1993

Skills training following revision of process specifications
Judged by Tanaka

Figure4-1 Typical certification record sheet (2/2)

9

JERG-0-039D(E)4.3 Design conditions
Design requirements for PWB and assemblies thereof shall be as per JERG -0-042.
Additional design requirements shall be as follows:(1) The requirements herein shall be applicable to designed parts containing solder
joints, the temperatures of which fall within the range of −55°C to 100°C duringstorage and operation. In case of deviations from this temperature range, appropriate
design measures shall be implemented.
(2) Except for special purposes, solder shall conform to Sn63/Pb37 or Sn60/Pb40
composition as per J-STD-006 or JIS Z 3282 or equivalent compositions. Flux-coredsolder shall be used with either RO-L0 flux (R equivalent) or RO-L1 flux (RMA
equivalent). Lead-free solder shall not be used in lieu of Sn63/Pb37 or Sn60/Pb40
solder. In addition, the Sn-Ag system may be used when the reliability of the junction
cannot be assured in paragraph 4.3 (4).
(3) Metal materials to be soldered shall have solder wettability and, unless otherwise
specified, shall allow soldering with rosin-based flux.
(4) Materials selection shall provide minimal thermal expansion coefficient mismatchat the constraint points of the part mounting configuration. If large thermal
expansion coefficient mismatch is unavoidable, comprehensive consideration shall begiven to the soldering method, surface plating, type of solder, as well as temperature
variation reduction through the use of built-in thermal control in the system, toensure reliability.
(5) Unless otherwise instructed, stress relief shall be incorporated, wherever possible,
to relieve thermal or mechanical stresses between two or more constraint points.
(6) Parts staking or conformal coating shall be performed carefully not to negate
stress relief.
(7) Solder joints shall allow visual inspection.
For BGA/CGA, follow to JERG-0-054.
4.4

Process certification tests

When any one of the items listed below applies, the process shall be tested for
certification or otherwise verified as certified.
(1) Soldered portions fall outside the temperature range of −55°C to 100°C duringstorage and operation.
(2) Any solder mounting unspecified herein is adopted.
(3) The consideration per paragraph 4.3 (4) finds that the process must be tested forverification regarding the thermal expansion coefficient mismatch. The test results
shall be incorporated into detailed manufacturing specifications (surface plating,shape, clearance, etc.) and inspection specifications for solder joints.

10

JERG-0-039D(E)4.4.1 Process certification test (I)In the case of paragraph 4.4 (1) or (3), the following shall apply:(1) Thermal cycle test
Thermal cycle test shall be conducted with a safety margin added to the temperaturechange pattern predicted by thermal analysis. The number of cycles shall be
determined based on the required life. When an accelerated test is required, thethermal cycle test shall be conditioned taking into consideration the amount ofthermal stress reducible from maximum and minimum temperatures.
(2) Visual inspection
After completion of the thermal cycle test per Item (1) above, visual inspection shallbe conducted with minimum 15x magnification to verify that no deeply cracked solder
joint or any other part damage has occurred. If visual inspection alone is insufficie nt
for verification, cross-sectional inspection shall also be performed. This test shall use
a multiple number of test specimens to verify the reproducibility of the design andmanufacturing quality per the process specifications. The accept/reject criteri a forcracked solder joints shall be evaluated and reviewed as necessary in cooperation with
the JAXA’s inspector.
4.4.2 Process certification test (II)In the case of Paragraph 4.4 (2), the following shall apply:(1) Thermal cycle test
The test specimen shall be thermally cycled 200 times from room temperature to 55°C to 100°C and back to room temperature at a temperature gradient not exceeding
5°C per minute. Exposure time at maximum and minimum temperatures shall be 15
minutes. The duration of each cycle should average two hours. When a gas phasethermal shock test chamber is used, the chamber manufacturer’s recommended
temperature gradient may be used.
If the thermal cycle test is replaced by a thermal shock test, the equivalent test
conditions shall be established with reference to JERG-0-043-TM001 Technical Data
20.
(2) Vibration test
After completion of the thermal cycle test, the test specimen shall be subjected tovibration. The vibration test shall be conditioned taking into consideration theapplicable environmental conditions, etc., and shall be reconditioned as necessary incooperation with the JAXA’s inspector.
(3) Visual inspection
Visual inspection shall be conducted as per Paragraph 4.4.1(2).

11JERG-0-039D(E)- Note Prior to a process certification test, a test plan shall be prepared that
explicitly states in detail the manufacturing requirements (surface
plating, dimensions, clearance, work conditions, equipment and facilities,etc.) and inspection requirements (appearance and shape of fillet, amountof solder to be used, etc.), and test requirements (environment, items to bemonitored).

4.5 Manufacturing conditions(1) Unless otherwise contractually specified, solder joints may be reworked within thelimits of applicability of this standard.
(2) Unless otherwise instructed, no repair of solder joints shall be allowed (e.g., repairof PWB solder lands, PWB processing for jumper wiring, etc.). Note, however, that
nonconforming solder joints may be reprocessed according to the nonconformity
handling procedures per the contract, on the condition that the intended f unction,
performance, or reliability will not be adversely affected.
(3) A non-nondestructive method of inspection, such as X-ray inspection, shall be usedas necessary to determine the acceptability of solder penetration.
(4) Materials and parts (including electrostatic discharge sensitive parts) shall beproperly stored and handled to prevent contamination and electrical or physicaldamage.
(5) Protective goggles, gloves, ventilation systems, and other necessary measures
shall be prepared to ensure personal safety.
Rework of soldered parts may be carried out within the scope of this document unlessotherwise specified in the contract.
4.5.1 Manufacturing environment(1) Facility cleanlinessa. The supplier shall ensure that the workplace used for the soldering is maintainedin a clean and orderly condition.
b. Smoking, eating, and drinking in the work area shall be prohibited.
c. Nonessential items shall not be brought into the work area.
d. Each workshop shall have an internal pressure higher than that of the adjacentareas or shall be installed with a double-layered entry and exit system to minimize
entry of external contaminants.
e. When any dust generating work is required, appropriate precautions shall betaken.

12

JERG-0-039D(E)f. Tools for use in individual workstations shall be maintained clean. Any
contaminants arising from the work (e.g., flux, solder droplets, metal filament, etc.)
shall be removed immediately.
g. Some supportive materials may contain harmful substances. Sufficientventilation shall be provided to ensure safety.
(2) Temperature and humidity
The temperature and humidity in individual soldering stations shall be controlled to
the ranges specified below and shall be continuously monitored. Parts or equipment
being processed that require more critical environmental conditions than thefollowing shall have such requirements identified and specified in the engineering
documentation.
a. Temperature; 24±5℃
b. Relative humidity; 30～65%(3) Lighting
Light intensity shall be a minimum of 1,000 lux on the surface being processed.
During high-precision work, supplementary lighting shall be used to increase thelighting intensity if needed.
4.5.2 In-progress storage and handling(1) When handling or storing in-progress or finished PWB assemblies, appropriate
precautions shall be taken to prevent damage, inclusions, or contaminants.
(2) No metal surfaces to be soldered shall be touched with the bare hands. In case ofcontact with the bare hands, the metal surface shall be cleaned immediately. If
handling of metal surfaces to be soldered is unavoidable, clean antistatic lint -freegloves or finger cots shall be worn.
4.5.3 Electrostatic discharge control
When electrostatic discharge (ESD) sensitive parts and assemblies are soldered, allinstruments and operators as well as the workplace shall be provided with the ESD
control measures listed below with due consideration given to personal safety. Proper
handling procedures shall be established, in which all operators and inspectors shallbe trained to develop proficiency in ESD damage prevention.
(1) Workbench surfaces shall be made and kept electrically conductive and grounded.
(2) If a workbench surface is not electrically conductive or if no ESD control system
is installed, each operator shall wear a wrist strap grounded via a protection resistor.
(3) Each operator shall wear a suit made of electrically conductive or non electrostatically chargeable fabric.
(4) The power supply equipment installed in the workplace shall be grounded by agrounding circuit that will remain closed even during a power failure.

13

JERG-0-039D(E)(5) Electrically conductive instruments and tools shall be used for work if necessary.
(6) Any container holding ESD sensitive parts in it shall be labeled to that effect.
(7) Only ESD-proof containers shall be used to keep parts or devices in it.
4.6 Quality assurance(1) The accept/reject criteria shall be explicitly defined in drawings and process
documentation.
(2) To verify conformance to the requirements herein, inspections shall be plannedand performed at appropriate points of time during the process.
It is desirable that the first product, the product that is not normally flowing, andthe critical product be confirmed by a manufacturing engineer.
(3) A quality assurance system shall be established to comprehensively review andverify the statements in the work and inspection records that the manufacturing
requirements are all met.
(4) Parts or PWB to be used shall be kept free of damage or deterioration to maintaintheir solderability.
(5)

The

manufacturing

environmental

conditions

humidity, and lighting of the facilities) shall be verified.

14(cleanliness,

temperature,JERG-0-039D(E)DETAILED REQUIREMENTS
5.1

Tools and equipment

5 . 1 . 1 Tools and equipment control(1) Tools and equipment to be used in soldering and in work preparation areas shallbe selected appropriately to the intended function.
(2) Tools and equipment shall be cleaned and properly maintained.
(3) The handling and operating procedures for the tools and equipment shall be
documented.
(4) All tools and apparatuses (e.g., soldering irons, insulation strippers) requiring
periodic inspection and calibration shall be properly labeled for identification,
controlled, and recorded per inspection and calibration procedures establishedtherefore.
(5) No unauthorized, defective, or uncalibrated tools shall be kept in the work area.
When temporary storage is required, all tools shall be properly labeled for
identification.
5 . 1 . 2 Soldering tools and equipment
Soldering iron or equipment shall be selected as appropriate for the workpiece to obtainan appropriate temperature profile. The use of soldering gun shall be prohibited. ( See
Figure 5-1)

Figure 5-1 Typical soldering gun (Prohibited)(1) Electrical tools, such as soldering irons and solder pots, shall have a three -core
power cord with a ground terminal or shall be double insulation. All soldering tips
shall be grounded that may directly contact parts and materials to be soldered. The
tip-ground resistance shall not exceed 2.0 Ω. The leak voltage shall be below 2mV(effective value).
(2) Soldering irons
Soldering irons shall be of temperature-controlled type; controllable within ± 5.5°C of
the set temperature.
(3) Solder pots
Solder pots used during tinning, etc., shall be capable of maintaining the solder

15

JERG-0-039D(E)temperature within ± 5.5°C of the intended range. Solder pots shall be grounded.
(4) Wave soldering equipment
Requirements for wave soldering equipment can be found in the paragraph 5.7.
(5) Supplemental heat sources
When supplemental heat is applied by hot gas, radiation energy, or any other source
for aiding the hand and wave soldering process, the equipment shall be set up,
operated, and maintained by personnel using established and documented procedures.
(6) Resistance-type soldering electrodes
Tweezer-type or clamp-type resistance soldering electrodes that come in contact withmaterials to be soldered shall be parallel to each other and free of pits, burns,
corrosion, or contamination.
(7) Hot air equipment (including hand tools)
Hot air equipment to heat the parts uniformly during soldering and rework .
5.1.3 Conductor preparation tool
Conductor preparation tools shall be selected as follows: Insulation strippers and leadbending tools shall not nick, ring, gouge, or scrape conductors or otherwise damage
parts. In addition, they shall not contaminate conductors or hinder solder wetting.
(1) Conductor cutting tools
Tools used to cut part leads shall not cause damage to printed wiring boards (PWB's),
printed circuitry, or part leads or bodies. For flash cutting tools (nippers, etc.) withblades on diagonal, side or end surfaces shall be used to cut leads of mechanicalshock-resistant parts (See Figure 5-2). Shear type cutters should be used to cut shocksensitive part leads to prevent damage.

16

JERG-0-039D(E)Parts body

Nipper blade

Appropriate example

Parts bodyParts body

Nipper blades

Nipper blades

Inappropriate example

Inappropriate example

Figure 5-2 Typical use of lead cutting nippers(2) Insulation stripping tools and methods
Tools used to strip insulation from wires shall be of appropriate type and size to avoid
nicking or scraping conductors or affecting the quality of insulation. Most appropriate
tools that best suit the wire shall be selected from the following:a. Mechanical strippers
Mechanical strippers used to remove insulation from stranded or solid conductor
wires may be of the hand operated or automatic high volume machine type. Hand
operated strippers shall be of a fixed die configuration (See Figure 5-3A,B).
Automatic high volume machine strippers shall be of a type using either fixed dies,
dies adjustable to calibrated stops, or roller cutters adjustable to calibrated stops.
Dies, whether adjustable or fixed, shall be properly maintained to assure
consistently sharp and even cuts without damage to the wire portions to be left foruse.
b. Thermal strippers
Thermal strippers used to remove insulation from stranded and solid conductor
wires shall be of a type that can provide a regulated temperature required for the
insulation type. Temperature controls shall be sufficient to prevent damage to thewire portions to be left for use (See Figure 5-3).

17

JERG-0-039D(E)c. Chemical strippers
Chemical solutions, pastes, or creams used to remove insulation from magnet wires
shall be suitable for removal of the insulation to be stripped and shall not cause
degradation to the wire. In addition, wires must be neutralized and cleaned ofcontaminants in accordance with manufacturer's recommended instructions.
d. Insulation removal using molten solder
Magnet wires can be stripped of polyurethane or similar type coatings by dippingin hot molten solder held at manufacturer’s recommended temperature.
Molten or re-solidified solder found at the termination ends of the remaining
insulation shall not be cause for rejection.
(3) Holding devices
Tools, fixtures, and materials used to hold or restrain conductors and parts shall beof a design that will not damage or deform the conductors, conductor insulation, orparts.
(4) Bending tools
Tools used for conductor bending may be automatic or hand operated and shall be ofa material that will not damage conductors or insulation. Bending tools shall be of a
type that imparts no damage to the part bodies or seals. Smooth impression marks(base metal not exposed) resulting from bending tool-holding forces shall not be cause
for rejection.
a. Automatic lead forming equipment
Automatic lead forming devices may be used that are capable of lead bending thatmeets the mounting requirements herein.
b. Clinching tools
Clinching tools shall not cause damage to PWBs, conductive circuit, or part bodies
or leads.

18

JERG-0-039D(E)A 適格なメカニカルストリッパの例
A. Typicaladequate mechanical cutting strippers

B. Typicalinadequate mechanical cutting strippers
B 不適格なメカニカルストリッパの例

C.
thermal stripper
C Typical
サーマルストリッパの例

Figure 5-3 Typical strippers

19

JERG-0-039D(E)(5) Anti-wicking tools
Anti-wicking tools shall be of a design that fits only a specific conductor gage size andshall be marked with that conductor gage size.
(6) Cleaning tools
Cleaning tools shall be selected based on their ability to minimize the generation of
static charge. Typical cleaning tools include natural bristle brushes, lint -free tissue,
cotton swabs, etc. Steel-wire brushes, knives, erasers, emery cloth, sandpaper, andother devices that produce an abrasive action or cause contamination shall not be
used.
5.1.4 Thermal shunts
Thermal shunts (also called heat sinks or heat dissipater clamps) shall be used toabsorb heat from part leads as necessary to protect parts, insulating materials, and/or
previously completed connections from damage during soldering operations. Care shallbe taken in the selection, application and removal of thermal shunts to avoid damage
to conductors, parts, insulation, or associated solder joints.
5.1.5 Inspection optics
Visual inspection shall be performed using magnification aids conforming to thefollowing:(1) Magnification aids that allow observation with both eyes are recommended for use
in solder joint inspection.
(2) Magnification aids shall be capable of rendering true color and adequate resolution.
(3) The light source shall provide shadowless illumination of the area being viewed.
(4) Inspection optics fitted with glass lenses are recommended.
5.2 Materials
5.2.1 Solder
All solder shall conform to J-STD-006 or JIS Z 3282 or shall be their equivalents and,
unless otherwise instructed, shall be selected as per the following guidelines:(1) Composition

Sn63/Pb37 or Sn60/Pb40(2) Flux types
Material

Activation level

RemarksRO

No Flux

S: Solid metal (no flux) equivalent

RO

L0

R: Rosin core-non-activated equivalent

RO

L1

RMA: Rosin core-mildly activated equivalent

Note:

Material RO: Rosin

20

JERG-0-039D(E)Type ROL0 flux (R equivalent) shall be used where cleaning cannot be sufficiently
performed after soldering. Type ROL1 flux (RMA equivalent) shall be properly removed
by sufficient cleaning after soldering.
[Reference] About solder(1) Typical forms and applications of solder are as follows:
W (wire)For hand soldering

R (ribbon)

For soldering using hot plate heating, etc.

B (bar)

For tinning and automatic soldering baths

I (ingot)

For tinning and automatic soldering baths(2) Unless otherwise instructed, the above-mentioned solder compositions shall be
used for soldering electronic devices. The following solder compositions may be usefulfor specific applications matching their physical properties. J -STD-006 or JIS Z 3282
shall be consulted for the details of solder compositions.
Soldercomposition
Sn62/Pb36/Ag2

Melting range °C
Solidus

Usage

Liquidus

Used to prevent silver coa ting on

179

ceramic substra tes from being diffused

Eutectic

into solder and cons equently thinned.
Used in high temperature

Sn96/Ag4

221

environments. Superior to tin-lead

Eutectic

solder in bond stren gth and e xcellent
in creep ru pture resi stance.
With a le ad content of 97 .5% .

Sn1/Pb97.5/Ag1.5

309

Used for high and cryogenic

Eutectic

applications.
Inferior to Sn63 in b ond strength .

(3) For soldering operations where connections are to be subsequently reheated, useof high temperature solder alloy is effective. In such cases, the type of hightemperature solder and the location requiring the high temperature solder shall be
specified in the engineering documentation.
5.2.2 Liquid flux
(1) Unless otherwise instructed, all fluxes used for soldering operations shall be Type
ROL0 (R equivalent) or ROL1 (RMA equivalent) liquid rosin flux per J -STD-004.
(2) Liquid flux used with flux-cored solder shall be chemically compatible with the21

JERG-0-039D(E)solder core flux and with the materials with which it will come in contact.
(3) Unless otherwise instructed, no corrosive water-soluble fluxes shall be used.
(4) The process documentation shall describe the types of fluxes, where each is used,
and the necessary precautions.
(5) Use of Type ROM1 liquid rosin flux (RA equivalent) shall be allowed only for
tinning of lead wires (solid conductor wires), solid bus wires, and terminals of sealed
bodied parts. Soldering with Type ROM1 liquid rosin flux shall be allowed only in aclosed area separated from the normal production line. No products soldered using
Type ROM1 (RA equivalent) flux shall be returned to the production line without
being completely cleaned of the flux.
[Reference] About fluxes(1) Some high lead content, high-temperature solder alloys may require high flux
activation temperature and use of inorganic corrosive flux. The inorganic corrosive
flux shall be subsequently removed by cleaning.
(2) Water soluble fluxes may not cause troubles immediately after cleaning but may
lead to insulation failure after long-term storage. In addition, these fluxes may leave
residual moisture behind, due to which molten solder may be scattered during
subsequent soldering operations.
(3) Normally, water-soluble fluxes contain polyethylene glycol (PEG) as solvent.
According to an engineering document*1, resin components and PEG contained inglass-epoxy substrates are combined with each other at soldering temperatures to
produce substances irremovable even by subsequent cleaning. Additionally, thedocument warns that the produced substances cause a rapid decrease in insulation
resistance when placed in high-humidity environment (75% to 80% or higher).
According to the same document, polypropylene glycol or its derivatives arealternative solvents effective to prevent this deterioration problem.
5.2.3 Solvents and cleaners(1) Solvent and cleaner requirements
a. The solvents, cleaners, and cleaning systems thereof used for removal of grease,oil, debris, flux, and other contaminants shall be selected for their ability to remove
both ionic and nonionic contamination. No use shall be made of the solvents or
cleaners without properly evaluating and verifying their cleaning performance andeffects on the parts or materials being cleaned.
b. The solvents or cleaners used shall not degrade the materials or parts being
cleaned.
c. All solvent and cleaner containers shall be properly labeled for identification.
d. The solvents and cleaners shall be properly controlled to prevent them from being

22

JERG-0-039D(E)contaminated, absorbing moisture, or being degraded during use or storage.
(2) Typical solvents and cleaners
Approved solvents and cleaners are as follows:a. Ethanol (Ethyl alcohol): JIS K 8101 (reagent) special grade or Grade 1 orequivalentb. 2-Propanol (Isopropyl alcohol) : JIS K 8839 (reagent) special grade or Grade 1 orequivalentc. Mixture of the above solventsd. Deionized water: minimum specific resistance 10 kΩ・m

- Note N o u s e s h a l l b e ma d e o f C F C , 1 , 1 , 1 - t r i c h l o r o e th a n e , o r a n yo t h e r s u b s t a n c e s p r o h i b i t e d u n d e r “M o n t re a l P r o t o c o l o n
S u b s ta n c e s t h a t D e p l e te t h e O z o n e L a ye r . ”(3) When selecting deionized water, care shall be exercised to ensure that proper
drying is accomplished immediately after its use.
(4) Solvents and cleaners may remove marking information from parts. Appropriate
marking permanency testing shall be performed as part of the evaluation procedure
for any solvent or cleaning system.

If markings other than indelible ink may

disappear, evidence shall be left.
[ R e f e rence]
Water-based saponifying detergents have relatively high surface tensions. Their use
should be avoided in high-density mounting or surface mounting, in which substratepart clearances may be too narrow for proper cleaning with them. Their residues may
cause corrosion.
5.2.4

Requirements for conductors to be soldered

Oxides on conducting metal surfaces result in poor solder wetting. Hence, in soldering
operations, surfaces are plated with oxidization-resistant metal for good solderability.
There are also, however, various constraints on plating operations, including, e.g.,solder’s contamination susceptibility, long-term stability, and wettability. The plating
specifications and materials selection shall take these points into consideration.
In bright plating operations, care shall be taken because organic substances containedin the brightener additive added to the plating bath may be entrapped in the plating

23

JERG-0-039D(E)film, thereby reducing the solder bond strength, and because plating containing
excessive contaminants may result in reduced solderability.
[Reference]: About plating materials and methods
When a plating operation is required, the most appropriate plating method shall beselected with consideration given to their characteristics described below. For the
specifications for part lead plating, MIL-STD-1276 shall be consulted.
(1) Gold plating
a. Gold plating reacts with tin contained in the solder, producing an intermetallic
compound (AuSn4). This gold-tin compound is harder than solder and is brittle. The
gold-tin intermetallic layer can easily crack, thereby causing failures.
b. In gold-tin plating, gold diffuses faster than tin. Where a sufficient amount ofgold plating remains, gold will diffuse with voids left in the remaining tin (SeeFigure 4-7-1 and 4-7-3 in JERG-0-039-TM001 Appendix: Technical Data 4). Thisphenomenon typically occurs at high temperature.
c. Bright gold plating soldered without tinning has lower creep characteristics. (SeeFigure 7-5-4 in JERG-0-039-TM001 Appendix: Technical Data 7)
d. To ensure high reliability, gold plating must be removed prior to soldering. Where
gold plating is required (for, e.g., corrosion prevention), care shall be exercised to
avoid making the gold plating layer thicker than necessary. Excessively thick gold
plating may not be properly removed just by dipping in molten solder.
e. Typical specifications can be found in the following standards:
AMS 2422 and ASTM B 488: Plating thickness 0.8 to 1.3 μm
Where solderability specifications exist, solderability testing is compulsory. High purity gold plating shall be applied within the above thickness range to ensure goodsolderability.
(2) Silver platinga. Silver plating provides the best solderability second only to gold plating, but does
not perform very well in terms of long-term storage. Additionally, silver plating also
has the disadvantage of blackening due to sulfuration caused by sulfur andcompounds thereof.
b. When applied with voltage under humid conditions, electrochemical migration
occurs, thereby providing a possible cause of reduced insulation resistance or shorts.
Silver plating shall be applied with careful consideration given to the conditions ofintended use.
c. Typical specifications is shown in the following standards:

24

JERG-0-039D(E)ASTM B 700: Plating thickness 3.8 to 8.9 μm(3) Tin platinga. Tin plating has good initial solderability but deteriorates significantly over time.
b. Tin plating is prone to diffusion with the base metal. During the burn -in
operation of the product, the tin plating diffuses into, e.g., the base copper, yielding
a dark gray intermetallic compound (Cu3Sn), which causes non -wetting. This
problem can be prevented by increasing the plating thickness to 2.5 μm or more.
c. Use of tin-plated and tin-based lead-free electrode parts shall be prohibited forfear of tin dendrite-induced electrical short-circuiting. When use of lead-free parts
is unavoidable, prior consultation shall be held with JAXA.
(4) Electrodeposited tin-lead plating, etc.
a. Excellent in solderability and long-term stability.
b. Typical specifications is shown in the following standards:
SAE-AMS-P-81728 (tin 50 to 70% + lead)
Average plating thickness after fusing: 7.6 to 12.7 μm
c. Molten solder coating shall be applied over any of the above-described plating.
Typical coating thickness: 5.1 μm or more
(5) Underplatinga. Use of zinc-containing base alloys, such as brass, may result in reduced
solderability due to diffusion of the zinc over the plating surface. To prevent thisphenomenon, nickel or copper plating shall be applied to a thickness of 2.5 μm or
more.
b. Typical specifications for nickel plating and copper plating can be found in SAE AMS-QQ-N-290 and AMS 2418, respectively.
c. Nickel plating shall immediately be overlaid with top -layer plating. A prolonged
exposure to air may result in reduced adhesion of the top-layer plating. Use of nickel
plating shall be avoided where its magnetism is undesirable.
Tin plating has good solderability in the initial stage, but has large time
deterioration.
5.3 Preparation for soldering
5.3.1 Parts and materials inspection(1) Prior to parts mounting, PWB shall be examined for any of the following defects:
a. Conductor pattern containing blisters, creases, or scratches exposing basematerial surface, or conductor pattern separated from base laminate (including
solder pad)25

JERG-0-039D(E)b. Base laminate containing interlayer delaminate, pits, or inclusions
c. Measling or crazing exceeding permissible value for substrated. Debris, oil, or any other contaminants on PWB
e. Lack of solder plating or coating on surfaces to be soldered(2) To obtain good solder joints, surfaces to be soldered must be free of contamination
with oil or residual salt from plating solution. These surfaces must be handled
carefully to avoid contamination and shall be cleaned properly with an appropriate
solvent prior to soldering. Insufficient cleaning will result in reduced solderability,
formation of voids, and reduced solder bond strength. Due care shall be taken in use
of ultrasonic cleaning that may cause damage to bonding wires inside parts. Ensurethat cleaning is compatible with the solderability of the parts and materials used.
(3) PWB shall be checked for clean surfaces and non-moisture-absorbing surfaces
before soldering.

De-moisturizing for methods for PWB include long-term storage

in dry air, heat drying, and vacuum drying at low temperatures.
The drying method, temperature, and time shall be specified according to the object
and specified in the process specification, etc. (approximately 8 hours or less fromdrying to soldering).

If the drying is insufficient, moisture absorbed by PWB causes

malfunction.
As an example of drying temperature and time, 1 hour is typical at 130 °C. Check therelevant current applicable data sheet (JAXA-ADS).
(4) Prior to soldering, thermal resistance of the parts and other constraints shall bechecked to avoid parts deterioration during soldering.
Example: - Soldering temperature and time for feed through ceramic capacitors- Soldering temperature and time for IC’s and transistors- Soldering temperature and time for fuses- Heating and cooling times for ceramic parts (preheating and avoidance of
rapid cooling)
5.3.2 Tools inspection(1) Tools shall be checked daily for appearances, operation, performance, etc.
(2) Each tip of soldering iron shall be checked daily and periodically for thefollowing points:
a. Proper insertionb. Mounting without looseningc. Cleanlinessd. No oxidation scale between tip and heating element
e. Ground continuity
f. Prior tip size relative to work involved

26

JERG-0-039D(E)g. Tip temperature
5.3.3 Wire preparation(1) Insulation removal
Proper insulation stripping tools listed in Paragraph 5.1.3 shall be used.
(2) Damage to insulation
After insulation removal, the remaining insulation on the conductors to be used shallnot be scratched, crushed, charred, or otherwise damaged in any way. Note, however,that slight discoloration, indentation or scraping on insulation termination ends fromthermal or mechanical stripping, etc. are acceptable.
(3) Damage to conductor
After the removal of insulation, the conductors shall be free of cuts or scratches that
expose the base material surface. No use shall be made of any conductors, such aspart lead wires, which have been reduced in cross-section area.
(4) Wire lay
The lay of wire strands shall be restored as neatly as possible to the original lay if
disturbed. The conductors shall be cleaned before restoring the strands back to theoriginal condition.
(5) Electrical wire cutting
The ends of electrical wires shall be cut, immediately before soldering, with sufficient
length left for proper stress relief.
(6) Splices
For splices, follow JERG-0-041.
5.3.4 Gold plating removal
All gold plating on surfaces to be soldered shall be removed by dipping into molten
solder or by a mechanical process. Gold plating removal shall be followed by tinning.
Where gold plating is removed during tinning, it is recommended to use separate solder
pots for gold plating removal and for tinning.

- Note The contact time between gold plating and molten solder
shall be sufficient to remove all gold from the conductor.
Thin residual bands of gold -tin intermetallic compound canseverely embrittle connections.

27

JERG-0-039D(E)5.3.5 Tinning(1) The portions of solid or stranded wires and part leads to be soldered shall be tinned.
(2) Preferred methods of tinning are ones that use solder pots or soldering irons.
(3) No conductors shall be dipped in the solder pot for more than 5 seconds.
(4) Liquid fluxes may be used. The flux shall be applied so that it does not flow under
the insulation except for traces carried by solder wicking. Flux shall be removed
carefully using a necessary minimum amount of cleaning solution to prevent it fromflowing under the conductor insulation.
(5) Hot solder tinning on part leads shall not extend closer than 0.51 mm to part
bodies, end seals, or insulation.
However, in the case that solder coating is permitted closer to the part bodies in theparts specifications, it can be allowed to extend closer than 0.51mm but the part
bodies, end seals or insulation shall be checked after tinning for any damage.
(6) Tinning personnel shall check and ensure that the tinned surfaces exhibit at least
95 percent coverage. The contours of stranded conductors shall be visible.
(7) Rework of any tinning shall be conducted by repeating the above -described steps.
If the rework fails to provide a sufficient coverage, the tinning shall be rejected andhandled in accordance with the nonconformity handling procedures.

- Note “ Nonwetting” or “de -wetting” observed after tinning shall beproperly handled or prevented from recurring in accordance withthe prescribed nonconformity handling procedures.

5.3.6 Solder pot control(1) Tinning solder pots shall be analyzed on an established schedule, based on usage,
to ensure that they meet the requirements of Table 5-1, and that the total of gold plus
copper does not exceed 0.3 percent. Records of the analyses shall be kept. The solder
pot may be dumped on an established schedule, based on usage, in lieu of analysis.
When the solder produces a dull, frosty, or granular appearance on the work, the pot
shall be immediately removed from use.

28

JERG-0-039D(E)Table 5-1 Solder contaminant levels maximum allowable percent by weight ofcontaminantContaminant

Percent Allowed (wt%)

copper

0.25 *1gole

0.20 *1

cadmium

0.005

zinc

0.005

aluminium

0.006

antimony

0.5

iron

0.02

arsenic

0.03

bismuth0.25

silver

0.10

nickel

0.01*1 The total of gold plus copper shall not exceed 0.3 wt%.
( 2 ) The following instructions shall be complied with to maintain the solder pot purity
at an appropriate level:a. Dross shall be removed from the solder bath surface prior to soldering.
b. Dross shall be removed regularly during soldering to prevent dross adhesion to
the solder workpieces.
(3) Tinning solder pots shall be maintained at required temperatures and monitored,
as a minimum, before and after each tinning operation or 8 hours period of pot
operation.
[Reference](1) Copper, gold, cadmium, zinc, and aluminum are metals most likely to be
accidentally mixed in during soldering operations and shall be paid particularattention to.
(2) Contaminants likely to be found in a solder bath and their adverse effects are as
follows:
a. Copper
Copper is a metal likely to be found on a surface to be soldered. Copper makes thesoldered surface rough, and hard and brittle. The copper content of a solder bathshall be maintained at 0.25 wt percent or less.
b. Gold29

JERG-0-039D(E)Similarly to copper, gold is a metal likely to be found on a surface to be soldered.
Inclusion of gold reduces solder flowability, thereby forming solder joints, eachwith a whitish surface. The gold content of a solder bath shall be maintained at
0.2 wt percent or less. The recommended control value is 0.08 wt percent.
c. Cadmium
Cadmium reduces solderability and gives a dull appearance to soldered surfaces.
d. Zinc
Adverse effects start to show in solder with its zinc content at 0.001 wt percent.
A zinc content of approximately 0.005 wt percent will reduce solder flowability andwettability, thereby producing a dull-looking solder joints.
e. Aluminum
An aluminum content of 0.001 wt percent or more is high enough to cause
accelerated solder surface oxidation. Consequently, soldered joints will have aporous, dull, granular-looking surface. When the solder contains an appropriate
amount of antimony, an aluminum-antimony intermetallic compound will be
produced, thereby suppressing the above-mentioned adverse effect.
f. Antimony
Solder with a high antimony content shows slightly reduced wettability and anincreased electrical resistance, but exhibits improved mechanical strength andcreep characteristics. Excessive antimony content in solder will reduce solder
flowability and bondability, thereby producing hard, brittle, and corrosion-prone
solder joints.
g. IronIron increases the melting point of the solder, causes the formation of FeSn2
therein, and reduces the workability of the solder. A solder joint with an excessiveiron content will show magnetism.
h. Arsenic
By adding arsenic, the solder undergoes mechanical property changes. Morespecifically, the solder becomes harder and more brittle. Solder containing it
appears bubbly and produces intermetallic compound dendrites.
i. Bismuth
Solder containing bismuth has a lower melting point but produces brittle solder
joints.
j. Silver
Silver contained in solder reduces leaching of silver plating.
k. Nickel
Nickel has a low solubility in solder. Solder containing nickel may result in rough surfaced solder joints.

30

JERG-0-039D(E)5.4

Parts mounting

5.4.1 General
Unless otherwise specified, JERG-0-042 shall apply. What follows presents soldering
considerations requiring particular caution during parts mounting to PWB. Alsopresented below are some additional requirements. Dimensions presented herein
provide inspection criteria for manufacturing purposes (for design dimensions, see
JERG-0-042).
(1) Stress relief
Stress relief shall be incorporated, wherever possible, between any points ofconstraint to protect parts and solder joints from detrimental stresses arising fromexpansion or contraction caused by thermal variations or mechanical excursions.
Excessive lead lengths or large loops between constraint points shall be avoided toprevent vibration damage or electronic performance problems. Leads shall not be
temporarily constrained against spring-back force during solder solidification so thatthe joint is subject to residual stress. Examples of stress relief are shown in Figures
throughout this document.
［Reference]
During soldering operations, metal materials such as lead wires often constrain PWBs
or organic materials, e.g., conformal coating, that have a relatively high thermal
expandability. Solder joints will fatigue while repeatedly exposed to thermal stresses
during soldering and operational thermal cycles.
If a soldering operation causes an excessive amount of thermal stress or spring backforce, the obtained solder joints will be exposed to continuous stresses, undergo
rearrangement of crystal structure, and end up with creep ruptures.
Solder fatigue is the function of the thermal cycle stress and the number of cycles(time), while solder creep is the function of stress and time. Therefore, most of solder
failures occur as a result of the combination of fatigue and creep.
For further information on these points, refer to JERG-0-039-TM001 Appendix:
Technical Data 5 and Technical Data 7.

- Notes E x t r e me

carecontaining

shall

be

mechanicallye x e r ci s e d
weak

in

the

p o rt i o n s ,handling

of

parts

s u chasglass

e n c a p s u l a t e d w e t t a n t a l u m ca p a c i t o r s . T h e c o n t e n t i n s i d e abrokenglass

casing

gr a d u a l l y31

d e t e r i o ra t e s ,ands u chJERG-0-039D(E)d e t e r i o r a t i o n s o f t e n f a i l t o b e d e t e ct e d i n e l e c t r i c a l te s t i n g
p e r f o r m e d i m m e d i a te l y a f t e r s o l d e r i n g .
( 2 ) Parts positioning
Parts, terminals, and conductors shall be mounted as follows:a. Solder joint check
Parts shall be mounted so that terminations of other parts are not obscured.
When this is not possible, interim assembly inspection shall occur to verify that the
obscured solder joints meet the requirements herein.
b. Parts on conductive circuit
Parts having conductive cases mounted over printed conductors or which are in close
proximity with other conductive materials shall be separated by insulation ofsuitable thickness. Insulation shall be accomplished so that part identification
markings remain visible and legible.
(3) Visibility of markings
Where possible, parts shall be mounted in such a manner that markings pertaining
to value, part type, etc., are visible. For parts marked in such a way that some of themarking will be hidden regardless of the orientation of the part, the following shallbe the order of precedence for which markings shall be visible:
a. Polarityb. Traceability code (if applicable)
c. Part number and characteristic value(4) Parts mounted extending over mounting surface edges
Unless otherwise specified in the engineering documentation, parts shall be mounted
on PWB, a terminal panel, or a chassis without extending over any edge of themounting surface.
(5) Hookup wires
Hookup wire, solid or stranded, shall be supported by a means other than the solder
connections or conformal coating if wire length exceeds 25mm.
(6) Glass encased parts
Glass encased parts such as diodes, thermistors, or resistors shall be covered withtransparent resilient sleeve or other approved material when epoxy material is used
for staking, conformal coating, or potting or where damage from other sources is likely.
The epoxy material shall not be applied directly to glass.

32

JERG-0-039D(E)- Notes W h e n u s i n g h e a t s h r i n ka b l e s l e e v e s , e xt r e m e c a re s h a l l b e t a k e n
t o p r e v e n t p a r t d a ma g e d u e t o s l e e ve s h ri n k a ge o r e x c e s s i v e h e a t .

( 7 ) Splice
When connecting a broken or damaged conductor such as part lead or PWB circuit,follow the contracted fault handling procedure.

(Follow JERG-0-041 for solder

splice.)(8) Contact with solder terminations
Part bodies shall not be in contact with soldered terminations.
(9) Mechanical fasteners
Where a part body is fastened by a combination of mechanical fastening elements(screws, etc.) and soldering, the part body shall first be mechanically fastened
according to the authorized method and then soldered to prevent application of any
mechanical stress to the solder joint(s).
(Example)- Soldering of L-shaped multi-polar connectors
An L-shaped multi-polar connector shall have its L-shaped lead soldered to the
PWB after the screw fastening of the connector body to the counterpart with acorrect tightening torque.
5.4.2 Lead cutting and bending(1) During bending or cutting, part leads shall be supported on the body side tominimize stress and avoid damage to seals or internal bonds.
(2) The distance from the bend to the end seal shall be approximately equal at eachend of the part.
(3) The distance from the part body to the start of the bend in a part lead shall betwice the lead diameter 0.76 mm minimum for round leads and twice the ribbon leadthickness 0.50 mm in minimum for ribbon leads. Where the lead is welded, theminimum distance is measured from the weld. The bending radius of the lead shallbe greater than the lead diameter for round leads or than the ribbon lead thickness
for ribbon leads (See Figure 5-4).
(4) The direction of the bend should not cause the identification markings on themounted part to be obscured.

33

JERG-0-039D(E)(5) Part leads shall be formed so that they may be installed into the holes in the PWB
without excessive deformation that can stress the part body or end seals.
(6) All lead wires shall be formed and tinned before mounting the part.
Where possible, part leads that are subject to stress corrosion cracking (e.g., Kovar
leads), shall be preformed and trimmed prior to tinning.
(7) Whether formed manually or by machine, part leads shall not be mounted if theyshow evidence of nicks or deformations. Smooth impression marks resulting from tool
holding forces shall not be cause for rejection.
(8) Tempered leads (sometimes referred to as pins) shall not be bent nor formed for
mounting purposes since body seals and connections internal to the part may bedamaged. Tempered leads or leads with a diameter of 1.27 mm (0.050 in) or more shallnot be cut with nippers or other tools that impart shock to connections internal to thepart.
(9) Spring back resulting from lead wire clinching shall be acceptable.
(10) No solder joints shall be cut after soldering.

34

JERG-0-039D(E)

2d min. (0.76(0.030) min.)2d min( 0.76(0.030) min.)d: nominal lead diameter
R: bending radius

A. Typical round lead wire

2t min.
(0.50(0.020) min.)R≧t
2 locationsR≧t
2 locations

t: nominal thickness of ribbon lead wire
R: Bending radius

Dimension in mm(in.)

B. Typical ribbon lead wire

- Notes It should be noted that the distance from the start of the bendin a part lead to the part body (2d min. in the above Figure) may
be specified differently for some parts.

Figure 5-4 Distance from to the part body to the start of the bend in a lead

35

JERG-0-039D(E)5.4.3

Mounting terminals

Use of terminals shall generally be restricted to situations where parts are expected tobe removed and replaced five times or more, or where there are other compelling design
requirements for their use.
(1) Terminals shall not be used as the interface connections in non -plated throughholes (non-PTH’s) in a double-sided PWB.
(2) Swage type terminals that are mounted in a plated through hole (PTH) shall be
secured to the PTH by an elliptical funnel swage to allow full filling of the PTH withsolder (See Figure 5-5). Terminals shall be swaged so that they can be rotated under
finger force.
(3) When the seating of a swage type terminal that is mounted in a non-PTH issoldered to a PWB, a roll type swage shall be used for securing the terminal ( See
Figure 5-6).
(4) PWB designs calling for soldering of the swaged end of the terminal to the printed
wiring conductor on a single-sided PWB shall have the terminal secured with a Vfunnel swage (See Figure 5-7).
(5) Swaging of terminals shall be performed in a way that does not damage the PWB.
(6) After swaging, the rolled area shall be free of circumferential chips or cracks, but
may have a maximum of three radial cracks, provided that the cracks are separated
by at least 90° and do not extend beyond the rolled area of the terminal ( See Figure
5-8)[Reference]
Where terminals are required, bronze terminals are preferred. The bronze terminals
shall be solder plated (fusing required unless otherwise instructed) or tin -lead coated.
When the base metal contains zinc as its component, as is the case with brass, the zinccomponent will be diffused over the surface of the plating, thereby reducing thesolderability. To prevent this from happening, the base metal shall be barrier -plated.
A recommended barrier plating specification is copper plating with a minimum
thickness of 0.003 mm (0.0001 in) (standardized in AMS 2418). Nickel plating may also
be used where its magnetism and somewhat inferior solderability to copper barrier
plating do not matter.

36

JERG-0-039D(E)Slightly flowed
solder fillet
Conductor
BoardsolderElliptical funnel swage(See detailed view)

Oval funnel clamping
Detailed View

Plating through-hole

Terminal
Front View

Side View

Figure 5-5 Terminal mounting by elliptical funnel type swage

37

JERG-0-039D(E)solderConductor
Board

Roll swage

Figure 5-6 Roll flange terminal

Figure 5-7 Terminal mounting by V-funnel swage

Radial cracks (3 max.)

Piece missing

Acceptable

Unacceptable

Figure 5-8 Terminal damage

38

JERG-0-039D(E)5.4.4 Mounting of parts to terminals(1) Parts shall be mounted parallel to, and in contact with, their mounting surface(See Figure 5-9). Slight angularity is permissible.
(2) The length of leads between parts and terminals should be approximately equal atboth ends, except when special part shapes require staggering.
(3) Where parts are mounted between other terminal types, it is mandatory to put astress relief bend in at least one lead. The part leads shall be formed into their final
shape, unless otherwise instructed.

- Notes Care

shall

be

exercised

connections

are

not

to

assuremechanicallythatswagedsolderstressedduringparts

mounting operations.
( 4 ) Lead wires shall be wrapped around terminals as per Paragraph 5.5.
SR=Stress relief bend
CP=Constraing pointd=Nominal lead diameter2d min.

CP
2d min.

Figure 5-9 Stress relief example

39

JERG-0-039D(E)5.4.5 Mounting leads and parts to PWBs
General(1) The joints shall be tinned before soldering. The solder terminations shall be visiblefor inspection after soldering.
(2) If a part has lead wires insulated by the part manufacturer, Care shall be takenthat the fillet at the end of the insulating coating does not enter the mounting hole orsolder joint.
(3) Parts shall be mounted so that their bodies will not obstruct solder flow to thecomponents side of plated through holes (See Figure 5-10).
(4) Lead connections shall be aligned, bent, or straight mounted in accordance withthe technical documents. Only one lead wire or part lead shall be inserted into onehole.
(5) In the cases where visual inspection cannot be accomplished, a non -destructive
method of inspection shall be performed (e.g., X-ray or fiberscope). The nondestructive method of inspection to be used shall be documented and approved by the
JAXA prior to use.

Any separation
would cause loss of

Part
Air

function.

Unacceptable

SolderNote: The solder is obstructed where the pressure of the air involved
during soldering is equal to that of the molten solder.
Figure 5-10 Mounting hole obstruction

Horizontal mount of axial leaded parts
Axial leaded parts intended for horizontal mounting shall be parallel to, and in contact
with, the mounting surface (See Figure 5-11). Slight angularity is permissible. Whenparts need to be bonded, slight spacing will be acceptable.
If a part body has a small diameter and the stress relief in its lead is filleted with solder,

40

JERG-0-039D(E)the part may be mounted slightly off the mounting surface.
If required to mount a part off the mounting surface, due consideration shall be given
to the vibration-proofing of the part.

Figure 5-11 Horizontal mount
Vertical mount of axial leaded parts (See Figure 5-12)(1) Plating through-hole
The end of the part body shall be mounted with at least 0.51 mm (0.020 in) to a
maximum of 1.27 mm (0.050 in) clearance above the PWB surface or as specified onengineering documentation. The end of the part is defined to include any extensions
such as cover fillet, solder seal, or weld bead.
(2) Non-plated-through hole
The end of the part body may be mounted flush with the PWB surface and shall beterminated with an off-the-pad-lap solder joint. The part shall be staked on the partside of the PWB. The opposite lead shall have two approximate right -angle bends.
Double bend
locations1.27 max.
(0.050)

Staking

0.51 min.

Staki(0.020)ng

A. Plated through hole

B. Non-plated through hole
Dimensions in mm(in.)

Figure 5-12 Vertical mount41

JERG-0-039D(E)Parts with leads terminating on opposite sides
Stress relief shall be provided in the part lead between the part body and solder
terminations (See Figure 5-13). The leads may be terminated by clinch, straightthrough, or off-the-pad-lap solder joint.

SR = Stress relief bend
CP = Constraint point

Figure 5-13 Stress relief part termination

Parts with leads terminating on the same side
Stress relief shall be provided by forming the part leads at a bend angle to the PWB of
not more than 95°nor less than 45°. (See Figure 5-14).
2d min.

Figure 5-14 Bend angle

42

JERG-0-039D(E)Parts with leads terminating on both sides
Stress relief shall always be provided in the part lead between the part body and solder
termination. When the part lead is used to interconnect opposite sides of a PWB, stressrelief or a plated through hole shall be provided (See Figure 5-15).
SR=Stress relief bend
CP=Constraint point

Figure 5-15 Conductors terminating on both sides

Lapped terminations
Lapped terminations consist of both round and flat ribbon leads. It is preferred that
leads be seated in contact with the termination area for the full length of the foot.
Separation between the foot of the lead and the surface of the termination area shallnot exceed 0.25mm (0.010 inches)0.25 mm (0.010 in.) (See Figure 5-16).

43

JERG-0-039D(E)Round lead

Ribbon lead
0.25 max.

0.25 max.

0.25 max.

0.25 max.

0.25 max.

0.25 max.

Side View
0.25 max.

0.25 max.

Front View
Dimension in mm (in)Figure 5-16 Lapped lead height above board

44

JERG-0-039D(E)(1) Lapped round leads (See Figure 5-17.)
The round lead shall overlap the solder pad (i.e., land) a minimum of 3.5 times thelead diameter to a maximum of 5.5 times the lead diameter, but in no case shall thelength be less than 1.27 mm. The cut-off end of the lead shall be no closer than half
the lead diameter to the edge of the solder pad. Only that portion of the lead extending
to the part body or to another soldered connection shall be beyond the solder pad. For
lapped terminations where the part body is on the same side of the PWB as the solder
pad, a heel fillet is mandatory.

3.5d~5.5d
1.27(0.050)min.

0.5d min.
d=Lead nominal diameter3.5d~5.5d
1.27(0.050)
min.

min.

A.

Mounting

along

through-hole

offset
3.5d~5.5d
1.27(0.050)min.

0.5d min.

3.5d~5.5d
1.27(0.050)
min.

D=Nominal lead diameter
R=Bend radius

0.5d min.

Heal fillet.

B. Surface mounting

Dimensions in mm (inch)

Figure 5-17 Lapped round termination

45

JERG-0-039D(E)(2) Lapped ribbon leads (See Figure 5-18)
The ribbon lead shall overlap the solder pad (i.e., land) a minimum of 3.0 lead widths
to a maximum of 5.5 lead widths. Only that portion of the lead extending to the part
body shall be beyond the pad. The cut-off end of the lead shall be a minimum of 0.25
mm from the end of the pad. One edge of the lead may be flush with the edge of thesolder pad. There shall be sufficient area around two of the three lead edges toaccommodate solder filleting. If the ribbon lead width is less than 0.5mm, the length
shall be 1.27 mm or more. For lapped terminations where the part body is on the sameside of the PWB as the solder pad, a heel fillet is mandatory.
3W
Min.

2.54 min.
(0.100)W+0.38 min.
(0.015)0.25 min.
(0.010)3.0W~5.5W
W+0.38 min
1.27(0.050)
min.

W=nominal leadwidth of ribbon leadwire

A. Mounting along through-hole
offset1.5W min.

0.25(0.010) min.
Heel filletmin.

W=nominal lead width of ribbon lead wiret=Nominal thickness of ribbon lead wire
R=Ribbon bend radius

B. Single surface lapped termination
Dimensions in mm (inch)

Figure 5-18 Lapped ribbon lead46

JERG-0-039D(E)Clinched lead terminations (See Figure 5-19)
The length of the clinched portion of conductors and part leads shall be at least ½ thelargest dimension of the solder pad or 0.78mm (0.031 inch), whichever is greater. Leadoverhang shall not violate minimum electrical spacing requirements.

The lead shallbe bent in the direction of the longest dimension of the solder pad. If the pad dimensions
are not sufficient, the lead shall be bent in the direction of the printed wire path. There
shall be sufficient solder pad area extending beyond the sides of the lead toaccommodate solder filleting. Fully clinched leads are defined as leads bent between
75°and 90° from a vertical line perpendicular to the PWB ( See Figure 5-20).
bendable leads shall not be clinched.

Clinched leads

Conductor pattern

Printed wiring termination
areas

Printed wiring board)

Figure 5-19 Clinched termination

75°min.

Figure 5-20 Lead bend

47

Non-

JERG-0-039D(E)Straight-through lead terminations
Part leads terminated straight through the PWB shall extend a minimum of 0.5 mm
and a maximum of 2.28 mm (See Figure 5-21). The minimum lead length shall bechecked prior to soldering (actual measurement is not required except for referee
purposes). Straight-through leads may be bent up to 30° from a vertical plane to retainparts during the soldering operation (See Figure 5-22). Non-bendable leads shall not bebent.

Non-plated through hole0.5(0.020) min.
Solder pad

2.28(0.090) max.

Plated through hole0.5(0.020) min.
2.28(0.090) max.

Figure 5-21 Straight-through termination

Axis of hole

Figure 5-22 Straight-through lead retention

48

JERG-0-039D(E)

5.5 Attaching conductors to terminals
5.5.1 General
Part leads and wires shall be installed as follows.
(1) Minimum insulation coating clearance
The insulation shall not be imbedded in the solder joint. The contour of the conductor
shall not be obscured at the termination end of the insulation.
(2) Maximum insulation clearance
The insulation clearance shall be less than two wire diameters, including insulation,
but in no case shall permit shorting between adjacent conductors.
(3) Multiple parallel entry
The insulating coating clearance of the conductors mounted in parallel to one terminal
may not be equal.
(4) Special cases
When characteristic impedance or other circuit parameters are affected, as in high voltage circuits or coaxial line terminations, the insulation clearance requirements
may be modified.
(5) Breakouts from wire harness
For multiple conductors routed from a common wire harness to equally spaced
soldered terminals, the length of the conductor ends, including bend allowance, shallbe uniform to prevent stress concentration on any one conductor.
(6) Mechanical support
Wire harnesses shall be supported so that the solder connections are not subjected tomechanical loads (See Figure 5-23). The methods, means, and location of this support
shall be specified on the design engineering documentation.

Clamp

Stress relief

Figure 5-23 Attachment to wire harness terminals

49

JERG-0-039D(E)( 7 ) S tress relief
Conductors shall be provided with sufficient slack to preclude tension on the solder
termination or conductor.
(8) Wrap orientation
Conductors may be wrapped clockwise or counterclockwise on the terminal. The
conductor shall not interfere with the wrapping of other conductors on the terminal.
The wrap orientation of a conductor shall be along the direction of the last point ofcontact between the conductor and the terminal to obtain as neat a finished wrap as
possible (See Figure 5-24).

Unacceptable

Acceptable

Figure 5-24 Wrap orientation( 9 ) T erminal fill
Conductors and part leads shall be in full contact with the terminal. They shall not be
wrapped onto each other or extend beyond the top of the terminal.
(10) Parts leads
Part leads shall not be used as terminals unless the part is designed for the lead tofunction as a terminal.
(11) Mounting of parts to terminals
The mounting of parts shall comply with the requirement of Paragraphs 5.4.4 andParagraph 5.5.
(12) High-voltage lead wrap
High-voltage lead wraps shall be defined on the engineering documentation.

50

JERG-0-039D(E)5.5.2

Turret and straight pin terminal(1) Side route
The side route shall be connected as follows:a. Conductors size larger than AWG 26 shall be wrapped a minimum of 180° to a
maximum of 270° around the post (See Figure 5-25A).
b. Conductors size AWG 26 and smaller shall be wrapped a minimum of 180° but
less than 360° around the post (See Figure 5-25B). However, AWG 30 or smaller
conductors may be wrapped three times as a maximum.
The side insertion route shall be connected as follows.
a. Wires thicker than AWG26 shall be wound 180° to 270° around the terminal.
(See Figure 5-25A)
b. AWG26 and smaller wires shall be wrapped 180° to 360° around the terminals(See Figure 5-25B).
However, AWG30 and smaller wires may be wrapped not more than three times.

Terminal post
180°=1/2 turn min.

Acceptable range

270°=3/4 turn max.

Terminal post
180°=1/2 turn min.

360°=One full turn max.

Acceptable range(When wire size AWG26 or
smaller)

Figure 5-25 Conductor wrap

51

JERG-0-039D(E)c. For turret terminals, all conductors shall be confined to the guide slots (SeeFigure 5-26A).
d. Conductors shall be maintained in contact with the terminal post for the fullcurvature of the wrap. The conductor ends shall not extend beyond the base of theterminal.
e. More than one conductor may be installed in a single slot of sufficient height.
Conductors shall be attached to the flange in order of proximity to the flange. Leadwires shall be connected without having their insulation interfering with eachother.
(2) Bottom route
The conductor shall enter the terminal from the bottom, be brought through the sideslot at the top, and be wrapped as required for side route ( See Figure 5-26B).

Insulation
Upper guide

Clearance

grooveLower guide groove

Insulation Clearance
FlangeFigure 5-26 Turret terminal(3) Continuous run wrapping
If three or more terminals in a row are to be connected, a solid jumper wire may becontinued from terminal to terminal (See Figure 5-27). The wrap to the first and lastterminal of the series shall conform to Paragraph 5.5.2 (1)a or (1)b, depending on the
conductor size.

52

JERG-0-039D(E)Figure 5-27 Continuous run wrapping - turret terminals
5.5.3

Bifurcated terminal(1) Bottom route
The bottom route shall be connected as shown in Figure 5-28.
Conductors shall not extend beyond the diameter of the flange, except as shown in
Figure 5-28(c), which is acceptable only when physical clearance is adequate for theintended environmental and electrical characteristics. When more than one
conductor is to be attached, it shall be inserted at the same time but shall be wrapped
alternately around separate posts.
(2) Side routeSide route shall be connected as shown in Figure 5-29.
a. The conductor shall enter the mounting slot perpendicular to the posts.
b. A conductor may lay straight through a terminal slot provided the conductor
surface remains in contact with the terminal surface. Where conductors arewrapped on a terminal post, they shall wrap minimum of 90° to a maximum of180°.

(Figure 5-30).

c. Conductors shall be in full contact with the posts and flange.
d. When sufficient vertical space is available, more than one conductor may beinstalled on a single post provided each conductor is wrapped on the terminal post
and not on another conductor. The direction of the bend of each additional
conductor shall alternate (Figure 5-29B or D). The order of installation shall befrom the side closest to the flange. When differently sized electrical wires areconnected to one terminal, the wires shall be connected in the order of size with the
thickest wire to the flange side.
e. Conductors shall not extend beyond the diameter of the base of the terminal
except where physical clearance will not adversely affect environmental orelectrical characteristics.

(See Figure 5-29C)(3) Side and bottom insertion route installation sequencea. The bottom route shall be installed first as shown in Figure 5 -28.
b. Then, the side route shall be installed as shown in Figure 5-29.

53

JERG-0-039D(E)

Post

Bending
Bending
ShoulderMinimum insulation clearance

Figure 5-28 Bottom route connections to bifurcated terminals

Insulation
Clearance

Insulation
Clearance

Insulation
Clearance

Insulation Clearance

Figure 5-29 Side route connections to bifurcated terminals

54

JERG-0-039D(E)Terminal Flange

Lead

Figure 5-30 Lead wrap
(4) Continuous run connections
When a series of terminals are to be connected to each other, such interconnections
shall be made with a solid wire in accordance with Figure 5 -31 or 5-32. The wire
shall be attached to the first and last terminal in accordance with Paragraph 5.5.3(2).

Figure 5-31 Continuous run wrapping/bifurcated terminals

Figure 5-32 Continuous run wrapping /bifurcated terminals alternate procedure55

JERG-0-039D(E)5.5.4 Hook terminal
Connections to hook terminals shall be as shown in Figure 5 -33. The bend to attach
conductors to hook terminals shall be a minimum of a 1/2 turn (180°) to a maximum of
a 3/4 turn (270°). Protrusion of the conductor ends shall be controlled to avoid damage
to insulation sleeving.

When more than one conductor is connected to the terminal,

the direction of the bend of each additional conductor shall alternate. Conductor shallbe wrapped directly around terminals, not over conductors.

Insulation
clearance

Insulation
clearance

Ejector

B Multiple connections

A Single connection(Winding direction may
be the same method)

Figure 5-33 Connections to hook terminals
5.5.5 Pierced terminals
Connection to pierced terminals shall be in accordance with Figure 5 -34. When
attaching a conductor to a pierced terminal, the bending shall be from a minimum of
1/4 turn (90°) to a maximum of 1/2 turn (180°). The insulation sleeve shall not bedamaged by the protrusion of the wire.
Insulation clearance
Insulation
Conductor
Diameter
Maximum

Insulation
clearance

clearance
1/4 turn

Side Insertion
1/2 turn

Insulation clearance

Figure 5-34 Connection to pierced terminals

56

1/4 turn

JERG-0-039D(E)5.5.6 Solder cup (connector type)
Conductors shall enter the solder cup (connector type) as shown in Figure 5-35.
Conductors shall be bottomed in the cup and shall be in contact with the inner wall of
the cup. The maximum number of conductors shall be limited to those that can be incontact with the full length of the inner wall of the cup.

Insulation
clearance

Insulation
clearance

Conductors must

Conductors must
be bottomed

be bottomed

Figure 5-35 Connections to solder cups (connector type)
5.5.7 Solder cups (swaged type)
Connections to the solder cup (swaged type) shall be as shown in Figure 5 -36.
Conductors entering from the top shall be in contact with the inner wall of the cup andshall bottom in the cup or on the bottom conductor.

Wire shall contact the
Wire shall contact the
inner wall of the cup
terminal.

inner wall of the cup
terminal.
Conductor entering fromthe top shall bottom out on

The conductor

the conductor entering

entering from the top

from the bottom.

shall be bottomedout.
A When the top conductor is thin.

B When the upper conductor is thick.

Figure 5-36 Connection to solder cups (swaged type)57

JERG-0-039D(E)5.5.8 Insulation sleeving application
All joints required to be covered by insulation sleeving shall be inspected prior andafter sleeving. Heat shrinkable insulation sleeving shall be used for electricalinsulation as appropriate.
For example, elements, such as hook terminals, solder cups, and bus wires, which are
not protected by insulating grommets, potting, or conformal coating, shall be protectedby insulation sleeving. Where a part covered by insulation sleeving requires mechan ical
support, measures shall be taken to ensure that the part is not free to move within thesleeving.
Material selection shall be specified on the engineering documentation. Sleeving shallnot be pierced, split, charred, or otherwise damaged.
Whatever type of terminal connectors needs protection, insulation sleeving shall befitted on conductors prior to soldering and shall only cover completed, cleaned, andinspected solder joints. When finished, both ends of the sleeving shall overlap the wir einsulation by a length greater than the diameter of the wire.
- Notes 1. Extreme care shall be taken to prevent damage to the assembly due toexcessive heat while shrinking the sleeving.
2. The sleeving shall be shrunk without discoloration.

5.6 Hand soldering
5.6.1 General(1) Securing conductors
There shall be no relative motion between conductors, terminals, and PWB
termination areas during solder application and solidification. Conductors shall not
be temporarily constrained against spring-back force during solder solidification thatmay produce residual stress in the joint.
(2) Heat shunts
Thermal shunts shall be used when heat applied during the soldering operations may
degrade conductors, insulation, parts, or previously soldered connections.
(3) Inspection
Inspection criteria for inspection are listed Paragraph 5.8.4.
(4) Dip Soldering
Manual dip soldering of PWBs shall be prohibited.

58

JERG-0-039D(E)(5) Pattern repair
Repair of damaged or broken conductor patterns on PWBs shall be prohibited.
(6) CoolingPressurized air shall not be used to cool solder joints. Connections shall be cooled atroom temperature only.
(7) High voltage
High voltage connections where corona suppression is necessary shall be specified in
the engineering documentation. Where soldering of high voltage connections isrequired, all elements of the connection shall be covered by a smooth fillet and freeof discontinuity or severe change in contour.
(8) Soldering iron tip selection and temperature setting
Some parts that require soldering may have restrictions regarding heating
temperature and heating time. Soldering iron tips and soldering temperature shallbe selected as per the parts soldering requirements and the shape, material, andsurface treatment requirements for solder joints.
(9) Soldering flat surfaces together
When a flat surface is soldered to another flat surface (e.g., PWB to ribbon lead),voids (residual air voids) often occur in the middle of the bonded interface.
Appropriate measures, such as the following, shall be taken to prevent residual air
void formation in the bonded interface:- One-way solder application.
- The flat surfaces shall be slid (i.e., scrubbed) back and forth, left to right, to spreadthe solder all over before solder solidification.
- An air hole shall be opened in the middle of the flat conductor to be soldered.
5.6.2 Heat application(1) A soldering iron tip shall be applied to the solder work surface so that the surface
will reach the soldering temperature in the minimum required time.
(2) Soldering heat shall be applied carefully to prevent damage to the circuit,insulation, or adjacent parts. Thermal shunts shall be used where thermallysensitive parts may be affected by soldering heat.

- Notes Charred, molten, or burned parts shall be replaced.
(3) When a solder work surface has high thermal capacity, an appropriate
supplementary heat source shall be used.
(4) A solder work surface shall be properly preheated prior to solder application.

59

JERG-0-039D(E)5.6.3 Solder application
Soldering to terminals(1) Solder fillets
A fillet of solder shall be formed between the terminal and each side of the conductor
except when item a below applies:
a. Cup terminals
The solder shall form a fillet between the conductor and cup entry slot. The fillet
shall follow the contour of the cup opening within the limits illustrated in Appendix
II. Solder on the outside surface of the solder cup may be permissible to the extent
that it approximates tinning and does not interfere with the function of theassembly or the connector.
b. Contacts (See Figure 5-37.)
There shall be good wettability between the electrical wire or the lead and the cup.
Solder protruding from the outer surface of the solder cup shall take the form ofthin film. The solder shall be visible through the inspection hole. The solder
spillage shall be permissible to the extent that it has a slight rise from theinspection hole. The solder spillage shall not extend beyond the inspection hole tothe side face of the cup.
(2) Solder joint-to-insulation clearance
Insulation shall not be embedded in the solder joint but shall be removed so that theinsulation termination end does not interfere with visual access to the contour of the
conductor. The clearance from the insulation termination end to the solder joint sh all
not exceed twice of the insulation diameter. The general rule of thumb is that theclearance shall be approximately equal to the outer diameter of the insulation. The
conductor, however, shall not be short-circuited with other adjacent conductor.
(3) Wicking
Flow (wicking) of solder along the wire is permitted. Solder shall not make thepresence of the individual wire strands indistinguishable. An increased flow
(wicking) of solder along the wire increases the rigidity of the wire, making the solder
prone to cracks due to bending.
(4) High temperature soldering
For soldering operations where terminals are to be subsequently reheated, the useof high temperature solder is permitted. The solder used shall conform to therequirements specified in Paragraph 5.2.1.
(5) High voltage connections
Where the engineering documentation requires the soldering of high voltage
connections, the solder joints shall be spherical after normal soldering and inspection.
Spherical solder joints shall have a smooth surface, free of discontinuities or abruptchanges in contour (See Figure 5-38).

60

JERG-0-039D(E)- Solder visible thru inspection hole
- Good wetting between the wire orlead and cup- Thin film of solder spillage
Acceptextending along the outside surfaceof cup- Solder having a slight rise fromthe opening of the inspection hole
- Good wetting between wire or leadand cup- Excessive solder spillage onto theoutside surface- Non-wetting between wire or lead

Rejectand cup- Solder invisible thru theinspection hole
- Non-wetting between wire or leadand cup
Figure 5-37 Soldering of electrical wire and lead to contact

61

JERG-0-039D(E)Spherical solder

Parts

Terminal

Spherical solder
Lead
Parts
Terminal

Figure 5-38 Solder-ball termination

Non-plated-through-hole soldering
Solder fillets shall be complete and as shown in Figures II-1 through 3 in Appendix II.
Plated-through-hole soldering(1) In soldering a conductor into a PTH, heat may be applied to either or both sidesof the PTH, but solder shall only be applied to one side.
(2) On the solder application side of PTH
The quantity of solder shall meet all requirements established by this document.
(3) For the connection on the PTH side opposite from the solder application
The solder quantity shall, as a minimum, exhibit flow-through and bonding of thelead or conductor to the solder pad; but not necessarily wetting out to or around theentire periphery of the solder pad. A slight recessing or shrinkback of the solder into
the PTH below the solder pad shall be acceptable, providing the solder has obviously
wetted the lead and solder pad and the shrinkback is slight enough that it cannot be
construed to be a solder void or blow hole.

62

JERG-0-039D(E)- Notes Great care shall be taken in soldering adjacent to a wide-area conductor
pattern, e.g., ground plane, or a heat sink that absorbs heat from molten
solder and obstructs solder flow.

Lap terminations(1) A heel fillet is mandatory for all single surface lapped solder joints. The heel fillet
shall have a thickness of “solder thickness + lead thickness” as a minimum and shallbe continuous between the heel of the lead and the termination pad (land). The heel
fillet shall extend beyond the lower bend radius but shall not extend into the upper
bend radius (See Figure 5-39).
(2) Round lead lap terminations shall require a complete solder fillet around all sidesof the lead (See Figure 5-40).
(3) On ribbon lead lap terminations where one side of a lead is allowed to be flushwith the edge of the termination pad (land), a filet of solder shall be formed along
the opposite side and the cut edge.

Start of bend radiusbetween the upper andlower end points.

Heel fillet
Maximum acceptable heel
fillet flat and round leads“Solder thickness+lead thickness”
as a minimum.

Heel fillet

Heel fillet
Minimum acceptableheel fillet flat lead

Figure 5-39 Heel fillet

63

Minimum heel fillet
round lead

JERG-0-039D(E)Land edge
Lead
Solder Fillet

Pass

Land

Pass
(Minimum)

Figure 5-40 Round lead termination
5.6.4 Solder cleaning (after hand soldering)(1) The process documentation shall specify appropriate cleaning methods andprocedures.
(2) Interim cleaning
Soldering leaves residues, such as rosin solids contained in the flux. The residues
shall be removed during interim cleaning within 30 minutes after soldering byapplying an approved solvent as specified in paragraph 5.2.3. Solvents shall beapplied in a manner that will minimize wicking of the solvent under conductor
insulation and prevent its entry into the interior of parts.
(3) Final cleaning
Brushing may be used in conjunction with the solvents. The cleaning solvents andmethods used shall have no deleterious effects on the parts, PWBs, or solder joints.
Ultrasonic cleaning shall not be used for cleaning PWAs that contain IC’s, diodes,
transistors, and other electronic parts. After cleaning, there shall be no visible
evidence of flux residue or other contamination when examined. Where theengineering

documentation

specificallyprescribes

highelectricalinsulation

requirements, refer to JERG-0-039-TM001 Appendix: Technical Data 1.
(4) Cleaning of conformal coated assemblies
Conformal coated assemblies that require rework shall not be submerged in cleaning
solvents. Cleaning shall be limited to the area of rework.
5.6.5 Rework(1) Before removing a conductor, the solder joint shall be left to cool down to room
temperature. Heat shall be applied without damaging the circuit, insulation, or
adjacent parts. Parts shall be removed carefully without damaging PWBs.
(2) Solder shall be removed using wicking wires, etc. Use of vacuum solder removal64

JERG-0-039D(E)is not recommended. If use of vacuum solder removal is unavoidable, personnel shallbe properly trained to be capable of solder removal using the correct procedures andappropriate tools.
(3) Flux residues shall be removed from solder joints by cleaning.
(4) Resoldering shall be performed as per the rules herein.
(5) Unless otherwise instructed, any soldered portions shall be repaired as per thenonconformity handling procedures compliant with the contract. For the repair
method, refer to JERG-0-039-TM001 Appendix: Technical Data 8.
5.7 Wave soldering
5.7.1 Wave soldering process control
Where wave soldering is required, the process documentation shall specify the following
items to ensure proper process control:(1) Preheat temperature applied to PWB(2) Temperature of solder in solder bath
(3) PWB transfer conveyor speed and angle(4) Solder-wave height(5) Flux density(6) Flux height(7) Depth of PWA in wave
(8) Control of dross inhibitors(9) Allowable contaminants when the solder bath is analyzed(10) Frequency of maintenance and of analysis(11) Other factors affecting the quality of the connections in the end product.
Maintenance and calibration data shall be made available for inspection.
5.7.2 Materials
Materials to be used for wave soldering shall conform to the following requirements:(1) Solder
Solder to be used shall have the composition indicated in paragraph 5.2.1 andconform to J-STD-006 Type O (equivalent to Type S) or JIS Z 3282 or equivalents.
(2) Flux
Liquid flux to be used shall be liquid rosin flux meeting the requirements per
paragraph 5.2.2. Normally, isopropyl alcohol shall be used as a thinner solution andshall be compatible with the specifications of the liquid rosin flux.
(3) Solvents
PWAs shall be cleaned using solvents or cleaners per paragraph 5.2.3. The use ofwetting agents shall be followed by thorough deionized water rinsing and drying.
PWAs shall then be kept dry until conformally coated.

65

JERG-0-039D(E)5.7.3 Preparation and assembly(1) Only electroplated solder coated and fused conductor patterns or solder coatedconductor patterns shall be used in wave soldering of PWB. Part leads shall be tinned.
(2) Parts shall be mounted to meet the requirements per paragraph 5.4. Due caution
shall be exercised in parts mounting to prevent relative motion between the part andboard during solder solidification. If temporary clamping is used, it shall not result
in residual solder joint stresses from lead spring-back forces.
(3) PWB's shall be cleaned and de-moisturized prior to wave soldering. The drying
time and temperature shall be set as appropriate for the PWAs to be dried and shallbe specified in the process documentation. The drying shall be performed withineight hours after wave soldering. Drying time and temperature, and the time in andout of the oven or chamber shall be recorded. . PWB's may be stored for longer periodsof time in a controlled moisture free atmosphere.
(4) Metal surfaces that are not to be soldered shall be masked or coated with solder
resist prior to loading onto the carrier.
5.7.4 Process condition settings(1) Samples to be used for condition parameter setting
The wave soldering parameters listed above in Paragraph 5.7.1 shall be set prior towave soldering of products. These condition parameters shall be set using samples
equivalent to the PWAs used in the products.
(2) Flux application
Liquid flux shall be applied by dipping, spraying, brushing, rolling, or wave or foam
flux application to form a thin coating layer on the surface. The concentration of theflux shall be specified in the process documentation and shall be periodicallymeasured and controlled within the permissible range.
(3) Preheating of PWBPWB shall be preheated appropriately within the range of 71°C to 107°C. The
preheating temperature shall be measured at points preselected appropriately forthe types of the PWBs.

- Note –To prevent molten solder from scattering, flux shall be dried prior to wave
soldering until tacky-dry.

66

JERG-0-039D(E)(4) Conveyor speed
The conveyor speed shall be controlled to a preselected rate, which shall not vary
more than 25 mm per minute. An improperly set conveyor speed will lead tooverheating or insufficient heating, thereby resulting in solder spikes or bridges, a
reduced solder bond strength, or degradation of parts.
(5) Solder temperature
The temperature of molten solder for wave soldering shall be controlled so that thesolder in the wave making contact with the PWB falls within the range of 230°C ±3°C to 280°C ± 3°C. The temperature shall be set optimally for the conveyor speed.
(6) Solder wave height
The height of the solder wave shall be controlled to a constant preselected height. A
variable solder wave height will result in variations in solder dip time, thereby
affecting the solder bond strength.
(7) Contaminants in solder bath
The solder bath shall be controlled on an established schedule, based on usage, toensure it meets the requirements of Table 5-1. Anytime the solder produces a dull,
frosty, or granular appearance on the work, the bath shall be immediately removed
from use.
(8) Process log
Before feeding the product into the wave soldering machine, the wave soldering
conditions for each type of product shall be checked and set properly for operation. A
wave soldering log shall be recorded showing the preheating temperature, conveyor
speed, solder temperature range, wave height, and room temperature for each PWB
type. The log shall also be used to document results of periodical analyses prescribedabove in paragraphs 5.7.4 (2) and (7).
(9) Other
The solder bath shall be electrically grounded.
5.7.5 Solder cleaning (after wave soldering)(1) The process documentation shall specify appropriate cleaning methods andprocedures.
(2) As soon as possible after soldering, the flux, dross inhibitor, temporary solder
resist, and other contaminants shall be removed by cleaning with solvents, etc. The
cleaning shall not damage the hardware or make part markings illegible. Evidence
shall be left if markings other than indelible ink may disappear.
This shall be accomplished by use of an appropriate solvent meeting therequirements per paragraph 5.2.3, followed by rinsing with clean solvent to ensurecomplete removal of the residues.
(3) To verify the adequacy of cleanliness after the final rinsing, a periodic inspection67

JERG-0-039D(E)interval shall be determined according to which the resistivity or the degree of NaClequivalent ionic contamination shall be monitored. The inspection interval shall be
set as appropriate for the size and quantity of the PWBs. Refer to JERG-0-039-TM001
Appendix: Technical Data 1 for the evaluation method and criteria for the cleaning.
5.7.6 Rework
Rework and other reprocessing after wave soldering shall be performed as per
paragraph 5.6.5.
5.8 Quality assurance
5.8.1 Document control
Ensure that the required documents are maintained to the latest version andimplemented.
(1) Incorporation of the requirements herein into the design standard, process
specifications, work procedures, inspection procedures, etc. (paragraph 4.1)
(2) Training and certification of operators and inspectors (paragraph 4.2)
(3) In-process handling and storage (paragraph 4.5.2 (1))(4) Electrostatic discharge control program (paragraph 4.5.3)(5) Tool and equipment operating procedures (paragraph 5.1.1 (3))(6) Calibration system (paragraph 5.1.1 (4))(7) Use of supplementary heat sources (paragraph 5.1.2 (5))(8) Flux usage (paragraph 5.2.2 (4))(9) De-moisturizing of PWB (and PWA) (paragraphs 5.3.1 (3) and 5.7.3 (3))(10) Wave soldering procedures (paragraph 5.7.1)(11) Cleaning procedures (paragraphs 5.6.4 (1) and 5.7.5 (1))
5.8.2 Records
Ensure that the required records are properly maintained.
(1) Results of the vision examination (paragraph 4.2)
(2) Temperature and humidity monitoring (paragraph 4.5.1 (2))(3) Tools and equipment calibration (paragraph 5.1.1 (4))(4) De-moisturizing of PWB (and PWA) (paragraphs 5.3.1 (3) and 5.7.3 (3))(5) Special inspection of nonconforming proximity of tinning to part bodies(paragraph 5.3.5 (5))(6) Solder pot and bath analyses (paragraphs 5.3.6 and 5.7.4 (7))(7) Wave soldering log (paragraph 5.7.4 (8))(8) Monitoring of resistivity or NaCl equivalent ionic contamination(paragraph 5.7.5 (3))

68

JERG-0-039D(E)5.8.3 Verification of tools, equipment, and materials(1) Tools and equipment
All tools and equipment shall be verified for conformance to the applicablerequirements as found in paragraph 5.1.
(2) Materials
All materials shall conform to the requirements of paragraph 5.2. Material controls
shall be implemented to ensure that only conforming materials are used. Materials
not conforming or not required for the operations involved shall be removed from thework area or tagged non-usable.
5.8.4 Inspection
GeneralInspection for acceptability shall be performed on all solder connections, parts
mounting and conditions, conductor routing, and PWB features. Parts and conductors
shall not be physically disturbed to aid inspection. Visual inspection of all solderedconnections and adjacent areas shall be performed using magnification of 4x to 10x (10xwherever suspicious). Depending on the nature of the suspicion, JAXA shall be
consulted for use of additional magnification (Note, however, that additional
magnification shall not be overused at the expense of inspection of the entire solder
joint and adjacent area.) Inspection optics shall conform to the requirements ofparagraph 5.1.5.
Where visual inspection is not possible, other appropriate nondestructive means (e.g.,laminography, microfocus X-ray, fiberscope optics) shall be used.
The accept/reject criteria for the appearance of solder joints shall be as per paragraphs
5.3 through 5.7 and the paragraphs to follow. Appendix II shows the boundary samplesof typical solder joints.
Acceptance criteria(1) The appearance of the solder joint surface shall be smooth and shall have a finish
that may vary from satin to bright depending on the type of solder used.
(2) Solder shall wet all elements of the connection, except as noted item (5) below. The
solder shall fillet between connection elements over the complete periphery of theconnection as shown in the figures in Appendix II.
(3) A heel fillet is mandatory for all lapped solder joints.
(4) The lead contour shall be visible (except for high -voltage connections. Seeparagraph 5.6.3.1 (5)).
(5) PTH soldering:a. On the solder application, the quantity of solder shall meet the requirements

69

JERG-0-039D(E)established by this document.
b. On the side opposite from the solder application, the solder quantity shall, as aminimum, exhibit flow through and bonding of the lead or conductor to the solder
pad. However, the following cases are acceptable.
- A slight recessing or shrink-back of the solder into the plated through-hole(except for those regarded as caused by voids or blow holes)- Slight de-wetting of the solder around the periphery of the pad on the part sideof the PWB(6) Support for wires as identified on the engineering documentation.
(7) The presence of stress relief in leads or conductors to provide freedom of motion
between points of constraint.
(8) Support for parts as identified on the engineering documentation.
(9) Part markings visible and legible, or evidence available.
(10) Exposed ends of leads on straight-through terminations after soldering shall not
be cause for rejection if the PWB is to be conformally coated.
(11) Absence of defects listed in Paragraph 5.8.4.3.
Rejection criteria
The following are some characteristics of unsatisfactory condition for solder joints, anyof which are cause for rejection:(1) Conductors and partsa. Nicks, cuts (rubbing or slight indentation of the coating terminal by mechanicalstripper, etc. is acceptable), or charring of insulation (slight discoloration fromthermal stripping is acceptable).
b. Improper insulation clearance.
c. Improper tinning of part leads or conductors.
d. Separation of wire strands (bird caging).
e. Part improperly supported or positioned (polarity, centering, planarity).
f. Improper vertical mount of component (clearance)
g. Cut, nicked, stretched, or scraped leads or wires exposing the base metal (except
smooth impression marks resulting from bending tool holding forces)
h. Flux residue or other contaminants
Trace flux residues shall be acceptable if evaluation data obtained from aelectrochemical

migration resistance test provide objective engineering evidence

demonstrating that the flux residues produce no adverse effects.
i. Improper wrap or stress relief.
j. Epoxy on un-sleeved glass parts.
k. Unsupported hookup wires in excess of 25 mm length. (See Appendix I)
l. Swaging not in accordance with paragraph 5.4.3.

70

JERG-0-039D(E)m. Improper lead bending or cutting.
n. Splices used to repair broken or damaged conductor.
o. Breakout of conductors from wire bundles not in accordance with paragraph 5.5.1(5)p. Part leads used as terminals (except when designed as a terminal)q. Terminals or wires modified to fit.
r. Improper clinch length.
s. Improper lead protrusion through PWB.
t. Gaps between part leads and solder pads on lapped terminations.
u. A part obscuring the solder termination of another part (unless interim
inspection was performed)(2) Solder connections
a. Cold solder connection.
b. Overheated solder connection.
c. Fractured or disturbed solder connection.
d. Poor wetting.
e. Blowholes, pinholes, and voids (except pits defined in Appendix I)
f. Excessive solder (solder in the bend radius of axial leaded parts in PTHs is notcause for rejection, provided that the lead is properly formed, the topside bend
radius is discernible, and the solder does not extend to within one lead diameter ofthe part body or end seal).
g. Insufficient solder.
h. Splattering of flux or solder on adjacent areas
i. Rosin solder joint
j. Contamination (e.g., lint, flux, dirt).
Unless otherwise specifically instructed on foreign substance, immovable foreign
substance (that immovable with application of a small external force via, e.g., abamboo skewer) may be made tolerable by coating if the minimum pattern interval
minus diameter of the foreign substance meets the required minimum conductor
interval.
k. De-wettingl. Non-wetting
m. Part body (meniscus) in solder joint(3) Printed wiring board
a. Separation of the conductor pattern from substrate
b. Burns on substrate71

JERG-0-039D(E)c. Discoloration that bridges uncommon conductors (e.g., measling, halo effect).
d. Solder peaks, icicles, and bridging on conductor patterns.
e. Cut, nicked, gouged, or scraped printed wiring conductor that exposes base metal.
f. Cut, nicked, gouged, or scraped substrate that exposes PWBs glass fibers.
g. Delamination of the PWB substrate.
h. Solder mask tackiness, flaking, or separation from the substrate or conductors.
Necessity of repair (touch-up) on the peeled solder resist shall be determined as
per Table 5-2. Note, however, that neither of the following shall be considered
nonconforming: a solder-coated resist with slight peeling*1 that occurred around asoldered land during soldering or a printed wiring assembly to be conformallycoated. If extending between patterns and exposing the conductor underneath, asolder resist peeling area shall be touched up upon detection, small or not or
conformally coated or not.
i. Repaired or damaged printed wiring conductor pattern.
j. Blisters

Table 5-2 Necessity of touch-up of peeled solder resist
Location of peeling

Slight peeling*1

Non-slight peeling*1

On Conductor

Necessary*2

Necessary

Outside conductor

Unnecessary

Necessary

RejectRejectScratched
conductor*1：Slight peeling (of permissible size) means partial peeling occurring within
1 mm around the perimeter of the land.
*2: No touch-up necessary if conformally coated.

NOTES(1) For Primary data of evaluation test regarding soldering process, and Study of thetest results, refer to JERG-0-039-TM001 Appendix: Technical Data 2~11.
(2) Relevant referenced documents are listed in Appendix III.

72

JERG-0-039D(E)Appendix I Terms and definitions
The terms and definitions used in this standard are as follows.
A
Axial leaded part
A part with leads extending from both axial end surfaces.
B
Bifurcated (split) solder terminal
A terminal with a slot or split opening in which conductors are placed before soldering.
Birdcage
A defect in stranded wire where the strands in the stripped portion between the
covering of an insulated conductor and a soldered connection (or an end -pretinned lead)
have separated from the normal lay of the strands.
Blister
A raised area on the surface of the laminate caused by the pressure of volatile
substances entrapped within the laminate.
Blow holeA cavity in the solder surface whose opening has an irregular and jagged form, without
a smooth surface. (A defect caused by blowout of gas, associated with an excessive gap
between soldered parts, moisture absorption by the PWB, or improper cleaning after
plating.)
Bridging
A buildup of solder between parts, part leads, or PWB conductors that forms anundesired conductive path.
C
Cold solder connection
A solder joint exhibiting poor wetting and a grayish, porous appearance due toinsufficient heat, inadequate cleaning prior to soldering, or excessive impurities in thesolder.
Conformal coating
A thin electrically nonconductive protective coating applied to parts -mounted PWBs or
I-1

JERG-0-039D(E)PWAs for the purpose of moisture-proofing or insulation.
Contaminant
An impurity or foreign substance present in a material that affects one or more
properties of the material. A contaminant may be either ionic or nonionic. An ionic, or
polar, compound forms free ions when dissolved in water, making the water a more
conductive path. A nonionic substance does not form free ions, nor increase the water’s
conductivity. Ionic contaminants are usually processing residue such as flux activators,
fingerprints, and etching or plating solutions.
Crazing
An internal condition occurring in the laminate base material in which the glass fibers
are separated from the resin.
Cup terminal
A cylindrical terminal (e.g., solder-type connector) that is hollow half way through toaccommodate one or more conductors to be electrically connected.
D
Delamination
A separation between plies within a PWB base material or any planar separation within
a multilayer PWB.
Dewetting
A condition where molten solder at least adheres to a surface, but the appearance offillets seems to suggest insufficient wetting, which is usually weak in adhesion.
Disturbed solder joint
Unsatisfactory solder connection that results from relative motion between the
conductor and termination during solidification of the solder and usually has a wrinkled
surface.
Dross
Oxide and other contaminants that form on the surface of molten solder.
E
Excessive solder joint
Unsatisfactory connection wherein the solder obscures the configuration of theconnection.
I-2

JERG-0-039D(E)F
FilletA smooth concave buildup of material between two surfaces (e.g., a fillet of solder
between a conductor and a solder pad or terminal, or a fillet of conformal coating
between a component and a PWB).
Fractured solder joint
A joint showing evidence of cracking, resulting from relative movement between the
conductor and termination, after solidification of the solder.
H
Haloing
Mechanically induced fracturing or delaminating on or below the surface of the base
PWB material; it is usually exhibited by a light area around holes, other machined
areas, or both.
Hook terminal
A terminal formed in a hook shape.
I
Insufficient solder joint
A solder connection characterized by incomplete coverage of one or more of the metal
surfaces being joined or by incomplete solder fillets.
J
Jumper Wire
Connections between plated-through holes, terminals, conductor lands, and component
leads on printed wiring boards where there are no connections on the printed circuit.
LLand
A portion of a conductive pattern usually, but not exclusively, used for connection or
attachment, or both, of parts.
M
Measling
Discrete white spots below the surface of the insulated base material, usually causedby moisture, pressure, and/or thermally induced stress.
I-3

JERG-0-039D(E)N
Nonwetting
A condition whereby molten solder has wet a metal surface only partially or not at all;the base metal remains exposed.
O
Orange peel
A solder surface condition characterized by rough, noticeably irregular, or granular
texture, or streaks.
Overheated solder joint
An unsatisfactory solder joint, the surface of which is roughened (dull, whitish,
granular, and porous or pitted) due to overheating.
P
Pierced (perforated) terminal
A terminal containing a hole through which leads or wires are placed before soldering.
PinholeA solder connection with a small hole penetrating from the surface of the solder to avoid of unknown size within the solder connection.
Pit
A relatively small recess in the solder surface, the bottom of which is visible from all
angles of vision.
R
Radial leaded part
A part with lead wires extending from its side (e.g., transistors, ceramic capacitors).
Synonymous with “non-axial leaded part.”
RepairOperations performed on a nonconforming article to place it in usable condition. Repair
is distinguished from rework in that alternate processes based on new engineering
instructions for configurations different than normal are employed instead of
reprocessing.

I-4

JERG-0-039D(E)Rework
The reprocessing of articles or material that will make it conform to drawings,
specifications, and contract.
Reflow soldering
A process in which the solder pre-applied to a PWB with parts mounted in place isheated and melted, and then left to cool in order to join the parts by solder to the board.
Rosin solder connection
An unsatisfactory solder joint that has a film of rosin flux entrapped between
conductors (between a terminal and an electrical wire, or a pattern and a lead wire,etc.), resulting in incomplete electrical connection.
S
Solder
A nonferrous, fusible metallic alloy (consisting usually of tin and lead) used to join
metallic surfaces. Low in electrical resistance. Hence often used to join electrical wiring
connections.
Soldering
A process of joining metallic surfaces through the use of solder without direct fusion of
the base metals.
Solderability
The property of a surface that allows it to be wet by molten solder.
Solder connection
An electrical/mechanical connection that employs solder for the joining of two or moremetal surfaces.
Solder mask/resist
Coating material used in automatic soldering to prevent adherence of solder to selectedareas of a pattern.
Solder pad
See “land.”I-5

JERG-0-039D(E)Solder spatter
Irregularly shaped solder fragments detached from a solder joint.
Solder spike
A cone shaped peak or sharp point of solder usually formed by the premature coolingand solidification of solder on removal of the heat source. Synonymous with “icicle” or“peak.”
Staking
The process or condition in which parts or components mechanically mounted orsoldered to PWB’s are bonded and secured by means of electrically nonconductive
adhesive for enhanced support.
Stress relief
Bends formed in conductors to minimize stresses acting between connections.
T
Turret terminal
A round post-type grooved stud around which conductors are fastened before soldering.
V
Void
A space enclosed on all sides by the solder.
W
Wave soldering
A method of soldering complete PWAs where the PWB, with parts mounted, is passed
through one or more waves of molten solder, which is continuously moving to maintainfresh solder in contact with the PWB.
Wicking
A flow of molten solder or cleaning solution by capillary action.
Wetting
A condition whereby molten solder has spread all over and adhered to a solid metal
surface.

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JERG-0-039D(E)Appendix II Samples of solder joints
This Appendix contains photographs of boundary samples showing the permissible maximum andminimum amounts of solder used to form typical solder joints, as well as photographs of defectsamples. These photographs can be used as visual standards for workmanship inspection.
Paragraph 5.8 shall be consulted for individual inspection criteria.

Minimum

Maximum

Figure II-1: PWB clinched termination(Round lead soldered to circular pad)

Minimum

Maximum

Figure II-2: PWB stud termination - Type 1
Lead protrusion = 0.8 mm (0.03 in.)
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JERG-0-039D(E)Minimum

Maximum

Figure II-3: PWB stud termination - Type 2
Lead protrusion = 2.3 mm (0.09 in.)

Minimum

Maximum

Figure II-4: PWB lapped termination; Round lead
(Lead terminated on rectangular pad on same side as part)II-2

JERG-0-039D(E)Minimum

Maximum

Figure II-5: PWB lapped termination; Ribbon lead
(Lead terminated on rectangular pad on same side as part)

Minimum

Maximum

Figure II-6: PWB lapped termination; Round lead
(Lead terminated on rectangular pad on side opposite to part)II-3

JERG-0-039D(E)Minimum

Maximum

Figure II-7: PWB lapped termination; Ribbon lead
(Lead terminated on rectangular pad on side opposite to part)

Minimum

Maximum

Figure II-8: Terminal to be mounted on PWB(Turret terminal soldered to mounting pad)

II-4

JERG-0-039D(E)Minimum

Maximum

Figure II-9: Conductor wrapped around turret terminal - single wire

Minimum

Maximum

Figure II-10: Conductor wrapped around bifurcated terminal - single wire

II-5

JERG-0-039D(E)Minimum

Maximum

Figure II-11: Conductor wrapped around bifurcated terminal - two wires

Minimum

Maximum

Figure II-12: Conductor wrapped around hook terminal - single wire

II-6

JERG-0-039D(E)Minimum

Maximum

Figure II-13: Conductor insertion into cup terminal - connector type

(Source: I.T.R.I. reference material)

Figure II-14: Blowhole

II-7

JERG-0-039D(E)Figure II-15: Damaged conductor
Conductor broken due to bending insolder wicking

Minimum

Maximum

Figure II-16: Terminal to be secured to PWB with V-funnel swage

II-8

JERG-0-039D(E)Minimum

Maximum

Figure II-17: Terminal to be secured to PWB with elliptical funnel swage

Minimum

Maximum

Figure II-18: Strainer conductor insertion into bifurcated terminal

II-9