JERG-0-043E(E)General

STANDARD FOR SURFACE MOUNTSOLDERING PROCESS FOR SPACE USE

Mar. 29, 2022

Japan Aerospace Exploration Agency

JERG-0-043E(E)This is an English translation of JERG-0-043E 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 ortimeliness 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-0-043E(E)TABLE OF CONTENTS

1. 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
2. RELATED DOCUMENTS ........................................................................................................ 4
2.1 Applicable documents ............................................................................................................... 4
2.2 Reference documents ................................................................................................................ 5
3. TERMS AND DEFINITIONS .................................................................................................... 6
4. GENERAL REQUIREMENTS................................................................................................... 7
4.1 General ...................................................................................................................................... 7
4.2 Training and certification ........................................................................................................ 7
4.3 Design requirements ................................................................................................................ 7
4.4 Process certification tests ......................................................................................................... 8
4.4.1 Requirement category for certification of the soldering process ........................................ 8
4.4.2 Test method and conditions .................................................................................................. 9
4.5 Manufacturing conditions ...................................................................................................... 11
4.5.1 Manufacturing environment ............................................................................................... 11
4.5.2 In-process storage and handling ......................................................................................... 11
4.5.3 Electrostatic discharge control ........................................................................................... 11
4.6 Quality assurance ................................................................................................................... 11
5. DETAILED REQUIREMENTS ............................................................................................... 12
5.1 Detail design conditions ......................................................................................................... 125.1.1 Thermal stress ..................................................................................................................... 125.1.2 Design of a solder land ........................................................................................................ 12
5.2 Manufacturing process, tools, and equipment ...................................................................... 14-i -JERG-0-043E(E)5.2.1 Manufacturing process ........................................................................................................ 14
5.2.2 Tools and equipment ........................................................................................................... 15
5.3 Materials ................................................................................................................................. 16
5.3.1 Solder and flux ..................................................................................................................... 16
5.3.2 Adhesive for fixing of parts ................................................................................................. 18
5.3.3 Solvents and cleaners .......................................................................................................... 18
5.3.4 Surface treatment materials of parts and printed wiring board...................................... 20
5.4 Solder deposition ..................................................................................................................... 21
5.4.1 Solder deposition in total heating process ......................................................................... 21
5.4.2 Solder deposition in local heating process ......................................................................... 22
5.5 Feeding of adhesive for fixing of parts .................................................................................. 22
5.6 Installation of parts ................................................................................................................ 23
5.7 Soldering .................................................................................................................................. 25
5.7.1 Total heating process ........................................................................................................... 25
5.7.2 Local heating process........................................................................................................... 28
5.8 Cleaning and cleanliness test ................................................................................................ 29
5.8.1 Cleaning................................................................................................................................ 29
5.8.2 Cleanliness test .................................................................................................................... 29
5.9 Quality assurance ................................................................................................................... 31
5.9.1 Records ................................................................................................................................. 31
5.9.2 Inspection ............................................................................................................................. 31
5.9.3 Visual inspection .................................................................................................................. 31
5.9.4 Nondestructive inspection................................................................................................... 42
5.9.5 Functional test ..................................................................................................................... 42
5.9.6 Cleanliness test .................................................................................................................... 42
5.10 Rework of Solder Joint ......................................................................................................... 42
5.11 Evaluation and Judgment of Service Life of Solder Joint ................................................. 43
5.11.1 Evaluation and judgment by visual inspection ............................................................... 43
5.11.2 Evaluation and judgment of crack depths ....................................................................... 44
5.11.3 Evaluation and judgment by electrical characteristics................................................... 44

Appendix I Terms and definitions ............................................................................................. I-1-ii -JERG-0-043E(E)

LIST OF FIGURES
Figure 1-1 Soldered parts mounting method plan and checklist form ....................................... 3
Figure 5-1 Geometry of solder land for principal parts (unit: mm) .......................................... 13
Figure 5-2 Installation accuracy of the parts (chip and other types) ........................................ 24
Figure 5-3 Installation accuracy of the parts (gull wing lead type terminal) .......................... 24
Figure 5-4 Temperature profile for reference ............................................................................. 27
Figure 5-5 Location of the thermocouples for acquiring temperature profile .......................... 27
Figure 5-6 Chip parts ................................................................................................................... 33
Figure 5-7 L-Leaded parts............................................................................................................ 34
Figure 5-8 Bottom terminal parts................................................................................................ 35
Figure 5-9 LCC parts .................................................................................................................... 36
Figure 5-10 J-Leaded Parts .......................................................................................................... 37
Figure 5-11 Gull wing lead parts ................................................................................................. 38
Figure 5-12 MELF parts............................................................................................................... 39
Figure 5-13 Plate electrode parts (diode parts) .......................................................................... 40
Figure 5-14 Stacked capacitor parts ............................................................................................ 41

LIST OF TABLES
Table 5-1 Solder and flux materials ............................................................................................ 16
Table 5-2 Solder feed amount (for reference) .............................................................................. 22
Table 5-3 Temperature profile for reference by total heating process ...................................... 27
Table 5-4 Allowable limit for cleanliness test ............................................................................. 29
Table 5-5 Magnification for visual inspection ............................................................................. 31
Table 5-6 Visual inspection criteria for soldering of chip parts ................................................. 33
Table 5-7 Visual inspection criteria for soldering of L-leaded parts ......................................... 34
Table 5-8 Visual inspection criteria for soldering of bottom terminal parts ............................ 35
Table 5-9 Visual inspection criteria for soldering of LCC parts ................................................ 36
Table 5-10 Visual inspection criteria for soldering of J-leaded parts........................................ 37
Table 5-11 Visual inspection criteria for soldering of gull wing lead parts .............................. 38
Table 5-12 Visual inspection criteria for soldering of MELF parts ........................................... 39
Table 5-13 Visual inspection criteria for soldering of plate electrode parts (diode parts) ....... 40-iii -

JERG-0-043E(E)

Table 5-14 Visual inspection criteria for soldering of stacked capacitor parts......................... 41
Table 5-15 Evaluation and criteria for visual inspections ......................................................... 43
Table 5-16 Evaluation and criteria for crack depths .................................................................. 44
Table 5-17 Evaluation and criteria for electrical characteristics .............................................. 44
Table 5-18 Crack level class on solder surface based on visual inspection............................... 45
Table 5-19 Crack depth level class of solder joints ..................................................................... 46-iv -JERG-0-043E(E)1. GENERAL
1.1 Purpose
This standard describes the requirements for surface mount soldering process used in rockets
and artificial satellites (hereinafter the “spacecraft”) and the components installed on such
spacecraft.
1.2 Scope(1) This standard sets forth the requirements for the soldering of surface mounted partsin order to achieve highly reliable electrical connections.
(2) This standard shall apply when specified by contractual specifications. In this case,this standard must be followed by the supplier and subcontractors who will execute a partof the scope of any contract. However, when the type of wiring board specified in a contract
is a mixed type lead through and surface mount types, JERG-0-039 Standard for Soldering
Process for Space Use (hereinafter referred to as “JERG-0-039”) shall apply to leadthrough mounting, and this standard shall apply to the surface mounting. While thisstandard will not apply to hybrid IC and microwave IC, the qualification tests of the design
conditions shall be in accordance with these ss.
(3) When application of this standard is specified in the specifications and no other
instructions are issued, the applicable objects and items in this standard shall be as set
forth in paragraph 1.2.1 in accordance with the category of the developed items. Decisions
on exemptions to this standard shall be subject to presentation of the reason for such
exemption and consultation with Japan Aerospace Exploration Agency (hereinafterreferred to as the “JAXA”).
(4) BGA/CGA is based on JERG-0-054.
1.2.1 Type of development model, development model definition
When the design, prototype building, and the manufacture of the spacecraft is made, thefollowing classification shall apply.
(1) Engineering Model（EM *1 etc.)
As a minimum, the following paragraphs of this standard shall apply to the engineeringmodel for environmental tests and life tests. If the environmental test and life test is notconducted, this standard does not need to be applied.
4.2 Education, training, and qualification
4.5 Manufacturing conditions
4.6 Quality assurance(2) Actual Model（PM *2, PFM *3, and FM *4）
This standard shall apply to actual models.
(3) Repair and Spare Parts
This standard shall apply to repair and spare parts.

*1 EM: Engineering Model: Prototype Model*3 PFM : Proto-Flight Model*4 FM: Flight Model
*2 PM

- 1 -

JERG-0-043E(E)1.2.2 Foreign products
Regardless of the provisions in paragraph 1.2.1, the following documents may be appliedinstead of this standard to devices installed on spacecraft whose design, prototype building,manufacturing, and modification are performed outside Japan, and application of thisstandard is difficult.
a.

b.
c.

J-STD-001*S“Space Applications Electronic Hardware Addendum to IPC J-STD001* Requirements for Soldered Electrical and Electronic
Assemblies”
ECSS-Q-ST-70-08C “Manual soldering of high-reliability electrical connections”
ECSS-Q-ST-70-38C “High-reliability soldering for surface-mount and mixed
technology”

1.3 Supplement(1) Examination of the Soldering Processes
The supplier shall prepare the document for requalification of the soldering process andqualification test of the soldering process, including at least items (a) to (c) listed below, inthe format shown in Figure 1-1, which shall be subject to examination by JAXA. The
examination shall be conducted as a part of PDR and CDR.
a. New aspects of the process and the impact thereof on important quality
characteristics
b. Extent of constraints on functional and performance verification during thetesting and inspection 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 thisstandard into the materials (drawings, manufacturing process specifications, procedures,
administrative rules, etc.) relevant to the implementation items (design standardization,engineering documentation, shop floor control) of the quality, reliability, or
safety/development assurance program plan.
(3) Product verification
The supplier shall plan and conduct manufacturing engineers’ verification about initiallot products to which the review results are applied, products normally commerciallyunavailable, and mission-critical products.

- 2 -Soldered Parts Mounting Method Plan and Checklist

Parts shapes orAs-assembled
configuration
thereof

Soldering type
Mounting
MethodStaking
methodSpecificationsof PWB, etc.

Hand soldering: H
Wave Soldering: W
Reflow Soldering: R

Necessity*of
Necessity
Necessimanufactu
of process
ty of
ring
certificatio
recertifengineer’s
n testicationwitnessing

Remarks: Reasonsand supplementarycomments-3 JERG-0-043E(E)* Indicate “Required” when required to adopt a new process with no history of previous application to space flight vehicles 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-0-043E(E)

2. RELATED DOCUMENTS
The related documents are as follows. Disclosure of some JAXA documents and materials
may be restricted.
2.1 Applicable documents
The documents listed below form a part of this standard to the extent specified herein. Unlessotherwise specified, their latest versions at the time of application of this standard shall be
used.
(1) JAXA standards
a. JERG-0-039
b. JERG-0-040
c. JERG-0-041
d. JERG-0-042
e. JERG-0-054(2) Public standards
ANSI Standards
a. J-STD-004
b. J-STD-005
c. J-STD-006

JIS standards
a. JIS Z 3282
b. JIS Z 3284
IPC standards
a. J-STD-001
b.

IPC-TM-650

Standard for Soldering Process for Space UseStandard for Electronic Bonding Process for Space UseStandard for Electrical Wiring Process for Space UseStandards for Printed Wiring Boards and Assemblies forSpace Use
Standard for BGA/CGA Mounting Process for Space Use

Requirements for Soldering Fluxes
Requirements for Soldering Pastes
Requirements for Electronic Grade Solder Alloys andFluxed and Non-Fluxed Solid Solder for Electronic
Soldering Applications

Soft Solders—Chemical compositions and forms
Solder Paste

JOINT INDUSTRY STANDARD Requirements for
Soldered Electrical and Electronic Assemblies
Test Methods Manual- 4 -JERG-0-043E(E)

2.2 Reference documents

The following documents provide information supplementary to the contents of this standard:
JIS standards
a. JIS K 3362
b. JIS K 3363
c. JIS K 8101
d. JIS K 8839

Test Method of Household Synthetic Detergent
Testing Method for Biodegradability of Synthetic Detergent
Ethanol (99.5) (Reagent)
2-Propanol (Reagent)

MIL standards
a. MIL-STD-202b.

Test Methods Standard, Electronic and Electrical Component
Parts
MIL-STD-1276 Leads for Electronic Component Parts

FEDRAL standards
a. TT-I-735
ASTM standards
a. ASTM B 488
b.
c.

ASTM B 545
ASTM B 700

AMS standards
a. AMS 2418
b. AMS 2422

Isopropyl AlcoholStandard specification for Electrodeposited Coatings of Gold forEngineering Uses
Standard specification for Electrodeposited Coating of Tin
Standard specification for Electrodeposited Coating of Silver forEngineering use

Plating Copper
Plating, Gold

SAE-AMS (Aerospace Material Specification) standards
a. SAE-AMS-P-81728
Plating, Tin-Lead (Electrodeposited)b. SAE-AMS-QQ-N-290 Nickel Plating (Electrodeposited)
IPC standards
a. IPC-SM-782
b. J-STD-001*S

Surface Mount Land Patterns
Space Applications Electronic Hardware Addendum to J-STD001 Requirements for Soldered Electrical and Electronic
Assemblies
Note that * indicates the latest version.

JAXA document
a. JERG-0-043-TM001 Collection of Technical Data of Standard for Surface Mount
Soldering Process for Space Use (JERG-0-043)- 5 -JERG-0-043E(E)

ESA documents
a. ECSS-Q-ST-70-08C Manual soldering of high-reliability electrical connections
b. ECSS-Q-ST-70-38C High-reliability soldering for surface-mount and mixed
technology”

3. TERMS AND DEFINITIONS
Reference shall be made to Appendix I for the terms and definitions used in this standard.

- 6 -JERG-0-043E(E)

4. GENERAL REQUIREMENTS
4.1 General(1) The supplier shall ensure highly reliable solder joints for electrical connections throughthe appropriate design, control of tools, selection of materials, work processes, working
environment, and by careful operation by trained operators qualified for the work.
(2) The supplier shall verify that the soldering complies with the requirements of thisstandard (design and manufacturing conditions). In addition, the supplier shall establish
and maintain design standards and process specifications according to the requirementsof this standard and shall manufacture and provide control based on such design
standards and process specifications.
(3) The design engineer responsible for the design of surface mounted electronic devices(including design of patterns of the wiring boards) shall have adequate knowledge of therequirements of this standard.
(4) Unless application of this standard is specified in the specification or other documents
for the parts, internal connection of parts are not subject to the requirements of thisstandard. The supplier shall guarantee that the internal solder connections of parts will
not melt or deteriorate from pretinning or external connections.
4.2 Training and certification
Training and certification shall conform to JERG-0-039.
4.3 Design requirements
The design requirements for the wiring board and its assembly shall be in accordance with
JERG-0-042. Additional design requirements for soldering are shown as follows. For the fine
pitch package, the contents of JERG-0-043-TM001 Technical Data 19 (paragraph 2.2 JAXA
Document) shall be reflected.
(1) The specifications of herein shall apply to the products of which the designtemperature of the soldered section is within -30°C to +100°C. When the temperature isoutside this range, countermeasures in the design shall be incorporated.
(2) As a rule, solder pastes conforming to J-STD-005 or JIS Z 3284 shall be used insoldering. When rosin flux cored solder is used, the type of the flux shall be either RO-L0
or RO-L1 (R or RMA). Composition of the solder shall be Sn63/Pb37 or Sn60/Pb40 or theequivalent in accordance with J-STD-006 or JIS Z 3282. Lead-free solder shall not be usedinstead of Sn63/Pb37 and Sn60/Pb40. Where reliability of joining as specified in paragraph4.3(4) etc. cannot be assured, Sn-Ag and Sn-Au alloys may be used.
(3) Metals to be joined shall have properties which ensure wettability for the solder alloyand soldering shall be possible using rosin base flux as a rule.

- 7 -JERG-0-043E(E)(4) Materials of the parts to be joined with solder shall be a combination of materials thathave a thermal expansion coefficient not significantly different. Where thermal stresssignificantly affects the solder joint, the reliability of the joint shall be established after acomprehensive study of the joining method, surface plating, and the type of solder used,
including reduction of temperature change by thermal control in the system.
(5) Application of fixing of parts by bonding and conformal coatings shall be in accordancewith JERG-0-040.
(6) As a rule, inspection of the soldered joint can be made. BGA/CGA is based on JERG-0054.
4.4 Process certification tests
4.4.1 Requirement category for certification of the soldering process
When either of the cases shown in the Table below applies, a certification test under the subject
shall be conducted to verify the effectiveness of the process or provide proof that the process isverified.
As to thermal shock test, the evaluation test confirmed that the severity (with compatibility)of the test is equivalent to that of temperature cycling test required by JERG-0-039.
[Reference] For Comparative Evaluation in Thermal Shock Test and Temperature Cycling Test,refer to refer to JERG-0-043-TM001Techinical Data 20.
Requirement Category

Test Item

1

When temperature condition of -30C to +100C at Thermal shock test (I)the soldered area cannot be satisfied during
warehousing, storage, and in operation.

2

When verification by the test is considered necessary Thermal shock test (II)as the results of study of coefficient of thermal
expansion under paragraph 4.3(4).

3When mounting by soldering other than the method Thermal shock test (II)specified in this standard is employed,
Insulation reliability test
Note) Three test items specified in the right Vibration resistance testcolumn shall be separately conducted for
different samples as a rule. When thermal
shock test (II) falls under the requirement
category 1, the thermal shock test (I) shallapply.

4

Where resonance is anticipated in vehicle launching Vibration resistance test
and in operation with the wiring board in installed
condition.

- 8 -JERG-0-043E(E)4.4.2 Test method and conditions(1) Thermal shock test (I)The test shall establish the upper and lower limit temperature with allowance for thepattern of temperature change predicted by thermal analysis. The condition where
exposure of the solder joint of the sample to the upper and lower limit temperature for 30
minutes, respectively, shall be employed, but when longer exposure time is expected
because of the pattern, the exposure time shall be adjusted accordingly.
The number of thermal cycles shall be determined based on the required service life, andthe criteria for the external and internal defects and electrical characteristics shallconform to that of the thermal shock test (II).
(2) Thermal shock test (II)Five hundred cycles of temperature changes between -30°C and +100°C shall be repeated.
This is the minimum requirement for design and manufacturing, and test conditions shallbe set in consideration of the required service life of the device. Retention time for eachtemperature shall be 30 minutes at the solder joint of the sample, and the speed oftemperature change between -30°C and +100°C shall be within 5 minutes in ambient
temperature.
The criteria after completion of 500 cycles shall be as follows (see paragraph 5.11 fordetails).
a. Visual inspections shall be made at each 100 cycles or less with a minimum of 15x
magnification, and cracks where the length is 1/2 or more of the terminal width will be
detected as defects of the solder joint, and such data shall be Weibull analyzed. The
scale parameter (η) shall not be less than 500 cycles.
b. Samples after completion of 500 cycles shall be inspected and sectional analysis of
the solder joint where depth of the crack is considered largest and where severity inthermal stress design is considered high shall be performed to confirm that the depthof the crack shall not exceed 1/3 of the thickness of solder fillet.
c. Electrical characteristics shall be measured and no anomalies shall be observed
after completion of 500 cycles.
(3) Vibration test
Condition of the vibration test shall be determined in consideration of the environment ofuse. Conditions shall be determined after consultation with JAXA as required. Criteria at
the end of the test shall be as follows, and all the requirements shall be satisfied.
a. Visual inspection shall be conducted with minimum of 15x magnification, and no
crack of which depth is 1/2 or more of the terminal width in the solder joint shall beallowed.
b. Electrical characteristics shall be measured, and no anomalies shall be observed.
Where resonance is expected, tests shall be conducted using a vibration spectrum withallowance against the expected vibration pattern based on vibration analysis. In
particular, attention shall be paid to the installation method of the wiring board and to
the resonance of the wiring board induced by mass distribution on the board. The timeof the test shall be determined in consideration of time duration for the launch.

- 9 -JERG-0-043E(E)(4) Insulation reliability test
The test shall be conducted with the electrical loads for actual application continuously
applied in the environment at 60°C and 90% to 95% RH. Time duration of the test shallbe determined based on the expected environmental conditions. When condensation may
be possibly take place during warehousing, storage, or in operation, condensation cycle
test simulating such conditions shall be conducted.
Criteria at the end of the test shall be as follows and all the requirements shall besatisfied.
a. Functioning status of the wiring board shall be continuously monitored during thetest and no anomalies shall be allowed.
b. After completion of the test, visual inspection of the sections where spacing between
conductors is small shall be conducted with minimum of 15x magnification, and noelectrochemical migration shall be allowed.

－ NOTE －In planning of the certification test of the soldering process, detailmanufacturing specifications of the sample (surface treatment, dimensions,clearance, work conditions, manufacturing equipment, etc.) and inspection
specifications (external shape of the fillet, amount of solder, etc.) and test
conditions (environment, monitor items, etc.) shall be clearly defined.
Combined testing shall be considered for the devices used repeatedly.
Test conditions such as combined environment shall be referred to JERG-0-043TM001 Technical Data 19.

[Reference]
For Evaluation of Fine Pitch Package and Surface Mounting Method, refer to JERG-0-043TM001 Technical Data 19.
For Comparative Evaluation in Thermal Shock Test and Thermal Cycle Test, refer to JERG-0043-TM001 Technical Data 20.

- 10 -

JERG-0-043E(E)

4.5 Manufacturing conditions(1) Where soldering is applied at both sides of the wiring board, adequate consideration
shall be made for effect of heat generated by soldering at each side on the material of theparts and for effect on the preexisting solder joint by soldering applied later.
(2) Unless otherwise specified in the contract, soldering rework may be allowed (including
rework of local area after removal of solder on terminals entirely) to the extent specified
in this standard. In such a case, the area to be reworked or entire wiring board shall becleaned before rework. However, it shall be confirmed such cleaning may not adversely
affect reliability of the parts. When necessary, parts at the reworked area shall be replaced.
(3) Repair of the wiring board is prohibited in principle. However, where no adverse effecton functions, performance, reliability, etc. is expected, damage on the circuit may beprocessed in accordance with the procedure specified in the contract.
(4) X-ray inspection etc. shall be made as appropriate in order to determine whether
penetration of solder is adequate or to confirm the absence of possible internal defects
such as void.
(5) Adequate care shall be taken for storage and handling of materials and parts (including
those susceptible to electrostatic discharge) in order to avoid contamination and electricalor physical damages.
(6) For safety and health of workers, protective glasses, gloves, ventilation system shallbe used.
4.5.1 Manufacturing environment
Manufacturing environment shall conform to JERG-0-039.
4.5.2 In-process storage and handling(1) Metal surface to be soldered shall not be touched with bare hands. If touched
accidentally, the area shall be cleaned immediately. Where handling of the product byhand is unavoidable, lint-free gloves or fingerstalls shall be used.
(2) Appropriate protection shall be used in order to avoid damage, electrochemical
migration of foreign substances, and contamination to the wiring board assembly during
or after mounting of parts.
(3) In particular, after printing of the solder paste and mounting of the parts the work
shall be transferred to the next processing steps immediately in order to avoid problem
due to property change of the solder paste.
4.5.3 Electrostatic discharge control
Electrostatic discharge control shall conform to JERG-0-039.
4.6 Quality assurance
Quality assurance shall conform to JERG-0-039.

- 11 -

JERG-0-043E(E)5. DETAILED REQUIREMENTS
5.1 Detail design conditions
5.1.1 Thermal stress(1) In order to reduce thermal stress in the solder joint, combination of parts and thewiring board shall be as follows.
a. When a part equipped with terminals in a stress relief configuration is mounted.
… Combination with any type of the wiring board is acceptable as a rule.
b. When a part equipped with terminals in a non-stress relief configuration is
mounted.
…. Study of thermal stress due to difference in coefficient of thermal expansion shallbe made, and combinations shall be limited to the wiring board type to which
the service life can be guaranteed. Where necessary, the service life shall beverified by the test specified in paragraph 4.4.2 (2) of this standard.
i) In case of the concave fillet like in LCC configuration (Figure 5-1 (4)).
ii) In case of the convex fillet (Figure 5-1 (2) and (3)). Where spacing between thesolder joints are up to about 3 mm, combination of materials with different coefficientof thermal expansion (e.g. alumina element assembly and glass epoxy board) may
satisfy the requirements, however where spacing exceeds about 3 mm, suchcombination is difficult to be applied.
(2) Where the requirement is not satisfied under (1) b. above, extension of life by thefollowing method shall be considered, or changing in parts and the printed wiring boards
or improvement of temperature condition shall be considered.
a. Use of solder alloys that have better thermal fatigue properties…. See paragraph 5.3.1 of this standard
b. Consideration of other bonding method…… A method where a joint is not adversely affected by thermal stress such as awire bonding method.
－ NOTE －In the case of a part that generates significant heat internally, evaluation ofsolder joint by the power cycle test shall be considered.

[Reference]
For verification of thermal stress and strain due to various combinations of parts and printed
wiring boards, refer to JERG-0-043-TM001 Technical Data 1.
For verification of thermal fatigue life of solder joints due to various combinations of parts andprinted wiring boards, refer to JERG-0-043-TM001 Technical Data 19.
5.1.2 Design of a solder land
Design of the appropriate solder land shall be made to respective parts in order to form
appropriate solder fillet which shall be documented. Shape of land to be used as reference is- 12 -

JERG-0-043E(E)shown in Figure 5-1.
(1) In the case of Gull Wing Lead typeterminal (Terminal pitch 0.5 or more)(2) In the case of Chip Parts type terminal(External dimensions 2.0 x 1.25 or more)b1  0.5 mm, b2  0.2 mm

0 mm  b1  0.2 mm• In the case of QFP and SOP

H  b2  H + 0.2 mme-aW

W  a  W + 0.3 mm

Where, e: Pitch spacing, W: Lead width

W: Part width (Nominal dimension of the(Nominal dimension of the part)part): Constant determined by the pitch spacing( = 0.3 mm for 0.635 mm or more,  = 0.2
mm for less than 0.635 mm)• In the case of part having 2 or 3 terminals(transistor, diode, etc)a  W + 0.5(3) In the case of L-Leaded Parts typeterminal(External dimensions 3.2 x 1.6 or more)(1) In the case of LCC Parts type terminal(External dimensions 3.2 x 1.6 or more)

0  b1 0.1 mm
H - 0.2 mm  b2  H
W  a  W + 0.4 mm, W: Lead width(Nominal dimension of the part)0  b1 0.1 mm
H - 0.2 mm  b2  H
W  a  W + 0.4 mm, W: Lead width(Nominal dimension of the part)

Figure 5-1 Geometry of solder land for principal parts (unit: mm)- 13 -

JERG-0-043E(E)Note 1: The corners of the rectangular land may be rounded as required, although all thedrawings show a rectangular land shape.
[Reference]
For verification of thermal fatigue life due to configuration of solder land, refer to JERG-0-043TM001 Technical Data 3.
For evaluation of fine pitch package and surface mounting method, refer to JERG-0-043TM001 Technical Data 19.

5.2 Manufacturing process, tools, and equipment
5.2.1 Manufacturing process(1) In general, reflow soldering or hand soldering methods shall be used in order toachieve stable soldering and to avoid damage to the parts.
－ NOTES －i) If the flow-soldering method is employed, an adequate study shall bemade for stability of the process, and the certification test of the process as
set forth in Requirement 3 under paragraph 4.4.1 shall be conducted toprove satisfactory result because it is not good for achieving quality andfillet formation in soldering.
ii) Difference of skills among workers significantly affects quality in handsoldering, so it shall be completed by qualified trained workers underparagraph 4.2.

(2) The following requirements shall be satisfied when total heating is used.
a. Appropriate temperature profiles shall be established.
b. No damage shall be caused that may affect the quality and reliability of theelectronic parts and wiring boards.
－ NOTES －Because a variety of process versions are available in reflow process, thefollowing points shall be considered in selecting the process.
i) In the process principally using IR rays, temperature distribution on thesame wiring board tends to be large due to differences in the heat absorption
factor between parts and due to differences in the heat capacity of parts.
ii) In the process of VPS (Vapor Phase Soldering) temperature increases frompreheating to full heating are very steep, and it shall be demonstrated that
quality and reliability of electronic parts are not adversely affected.

- 14 -

JERG-0-043E(E)(3) The following requirements shall be satisfied when local heating is used.
a. Heating shall be possible without direct contact with the solder as a rule.
b. No damage that may affect quality and reliability of the electronic parts and thewiring board shall be caused.
c. When solder paste is used, soldering shall be possible for preheating and fullheating respectively, as a rule.
d. Temperature of the part terminal (soldered portion) shall reach +30°C to 50°C
above the liquid phase point of the solder used.
－ NOTES －When a solder paste is used:i) In resistance heating methods such as pulse heating method, solder may
be directly heated, which is not desirable due to potential changes in thesolder microstructure. A method using heating through the lead terminal
shall be used.
ii) In the method using a laser, considerable heat is applied in very shortperiod of time. In order to investigate effect of such heating on quality andreliability of the solder joint, adequate process certification test shall be
conducted to demonstrate, and absence of a problem shall be demonstrated.

[Reference]
For comparison of soldering methods, refer to JERG-0-043-TM001 Technical Data 4.
5.2.2 Tools and equipment
Tools and equipment shall conform to JERG-0-039 in addition to the following requirements.
(1) Total heating equipment of the reflow method shall be controlled appropriately.
－ NOTES －i) Impact on the solder joints due to vibration during transfer of the printed
wiring board shall be avoided.
ii) The required profile shall be obtained by temperature regulation andadjustment of transfer speed.
iii) In case of heating by airflow control, the parts shall not move by airflow.

(2) The soldering iron complying with the requirements of JERG-0-039 and having theappropriate shape and size of the tip suitable for the parts shall be used.

- 15 -

JERG-0-043E(E)5.3 Materials
5.3.1 Solder and flux
(1) Solder and flux shall be selected from those included in Table 5-1.
Table 5-1 Solder and flux materials
Item

Total Heating Method

Local Heating Method

Composition As a rule, Sn63/Pb37, Sn60/Pb40, or equivalent solder complying with JSTD-006 or JIS Z 3282 shall be used.
Use of lead free solder instead of Sn63/Pb37 or Sn60/Pb40 alloys is
prohibited. Notwithstanding the above, the other composition may be used
as shown below.
(1) When the material of the terminals of the wiring board or parts is Agbase alloy…… Sn62/Pb36/Ag2 (According to J-STD-006 or JIS Z 3282)(2) When the requirement for thermal fatigue life of the solder joint is notsatisfied, with alloys Sn63/Pb37, Sn60/Pb40, and (1) above.
……Sn-Ag eutectic solder(Sn96.5/Ag3.5 or Sn95.5/Ag3.5/Cu1.0)(3) When the requirement for thermal fatigue life of the solder joint is notsatisfied, even with alloys of (2) above.
……Au80/Sn20
Property

Solder paste complying with J-STD-

Either of the following shall be

005 or JIS Z 3284.

selected depending on the method

Grain shape and grain

application conditionand parts.
(1) Solder paste complying with JSTD-005 or JIS Z 3284.
(2) Flux cored wire solder

such as part density.

(3) Solder preform

size shall be selected
depending on

Flux

Fluxes RO-L0 or RO-L1 (R or RMA) complying with J-STD-004 shall be
used.

- 16 -

JERG-0-043E(E)－ NOTES －i) Among the alloy compositions of Table 5-1, (2) and (3) are high temperaturesolder and higher stress of the parts is introduced, and it shall be checked that theparts and printed wiring board are free of damage before use.
ii) Among the alloy compositions of Table 5-1, when Au-Sn solder is used, Au
plating shall be specified as surface preparation of the parts and printed wiringboard.
iii) Because some new fluxes cannot be detected by the evaluation according to JSTD-004 and rather deteriorate insulation resistance, the following evaluation iseffective.
- Resistance meter evaluation (IPC-TM-650)- Water drop electrochemical migration test(2) Where a part that is susceptible to heat in soldering has to be used and use of low
temperature solder with Bi added is considered, deterioration of mechanical strength will
be a problem, and at least the following tests shall be made to verify compliance with therequirements, in addition to the process qualification test under paragraph 4.4.1.
a. Mechanical strength in the thermal shock test
b. Vibration resistance after thermal shock testc. High temperature creep characteristics(3) Use of water-soluble fluxes for water cleaning is prohibited as a rule. However, its use
may be allowed when the flux is the non-halogen type and does not contain substancesthat are hard to clean due to reaction with the wiring board and when it can bedemonstrated that flux residue at the narrow spacing or on the surface of parts iscompletely removed by water cleaning and the insulation reliability test under paragraph4.4.1 shows satisfactory results.
[Reference]
For verification of the effect on thermal fatigue life by solder alloys, refer to JERG-0-043TM001 Technical Data 5.
For verification of the effect of electrochemical migration of solder alloys, refer to JERG-0-043TM001 Technical Data 6.
For verification of composition of fluxes, refer to JERG-0-043-TM001 Technical Data 7.

- 17 -

JERG-0-043E(E)5.3.2 Adhesive for fixing of parts
Adhesive to fix the parts shall satisfy the requirements of JERG-0-040 and satisfy the following
performance requirements.
a. Application (printing, transfer, dispensing, etc.) of the adhesive is easy and shapeafter application shall not significantly change.
b. Adhesive shall be heat cured and the temperature and time of curing shall not affectthe reliability of the printed wiring board and the parts.
c. Even after curing, removal of parts can be made without causing damage of theprinted wiring board.
5.3.3 Solvents and cleaners(1) Solvents and detergent used for removal of the flux, debris, and other contaminantsfrom the wiring board shall satisfy the following requirements.
a. Solvents and cleaners selected shall be capable of removing both ionizing and nonionizing contaminants combined with variety of cleaning method (jet spray etc.).
b. Solvents and cleaners shall not cause detrimental effect on the wiring board and theparts.
c. Solvents and cleaners shall be completely removed by rinsing and drying after
cleaning. Even when the solvent or detergent remains within the part or in a space
between the part and the wiring board, it shall not have a detrimental effect onreliability.
(2) Examples of solvents and cleaners to be used are as shown below.
a. Ethanol (ethyl alcohol), JIS K 8101 (Reagent Grade), Special or First grades, or
equivalentb. 2-Propanol (Iso-propyl alcohol), JIS K 8839 (Reagent Grade), Special or First grades,or equivalentc. Mixture of the solvents above
d. Other Solvents: Refer to JERG-0-043-TM001 Technical Data 8.

- 18 -

JERG-0-043E(E)－ NOTES －i) CFC-113, 1, 1, 1-trichloroethane, etc. is banned substances under the Montreal Protocol on
Substances That Deplete the Ozone Layer and shall not be used.
ii) When aqueous cleaners (including semi-aqueous detergent) that requires rinsing with purewater is used, attention shall be paid to the following points.
- Detergency may not be sufficient at the spaces between fine pitch leads and at the back of parts. Residues that are problematic for reliability tend to remain unless rinsing and drying is sufficiently
made.
- Water used for rinsing shall be deionized water with resistivity of 10 km as a minimum.
iii) Because surfactant included in alternative detergent *1 remaining on the wiring board may affectinsulation reliability, care shall be taken to avoid residues of the detergent (especially in narrowspacing).
*1: Freon 1.1.3 and 1,1,1 trichloroethane alternative cleaners.

iv) When aqueous detergent or semi-aqueous detergent that contains surfactant is used, detergent
penetrated into narrow spacing between parts or a part and wiring board tends to remain in suchspacing because the surfactant is not easily replaced with pure water rinsing, and an appropriate
cleaning method and control of the rinsing process is essential. Non-ionic surfactant *2 will
significantly affect insulation reliability with an increase in number of mols of ethylene oxide in themolecule.
*2: Non-ionic surfactant: While many surfactants show its surface activity with its aqueous solution ionized, certain
group of surfactants show surface activity without ionization in aqueous solution. These surfactants arecollectively called non-ionic surfactants.

v) When ionic residues on the wiring board having narrow spacing between parts or a part andwiring board are evaluated, evaluation shall take into account ionic residues in narrow spacing.
vi) When detergent containing non-ionic surfactant is used, evaluation by resistivity measurementof solvent extract and by sodium chloride equivalent ionic contamination test may not provide
adequate results. As method for evaluating cleanliness other than ionic residues, an analysis methodof the non-ionic surfactant described in JERG-0-043-TM001 Technical Data 18 can be effectivelyused.
vii) Because organic acids such as dicarboxylic acid and amine-halogenated hydrobromide containedin flux and solder paste will affect insulation reliability, they shall be completely removed by cleaning
to eliminate any possible residues.
viii) Because the solubility of the flux component (rosin) is dependent on solvents and cleaners, andcleaning time varies, care shall be taken. Effect on resins and rubbers is also different depending on
solvents and cleaners, care shall be taken.

- 19 -

JERG-0-043E(E)[Reference]
For Verification of Evaluation Method of Non-ionic Surfactant, refer to JERG-0-043-TM001
Technical Data 18.
For Evaluation Method of the Effect of Flux Residues, refer to JERG-0-043-TM001 Technical
Data 21.
(3) Because some solvents and cleaners my react with the component in the flux toproduce reaction products, care shall be taken on the effect in selection of combination.
(4) When the part is marked with ink, the marking may disappear or peel off due to solvent
or detergent. Marking permanency tests shall be conducted in selecting solvent, detergent,and cleaning systems.
[Reference]
For comparison of principal cleaning methods, refer to JERG-0-043-TM001 Technical Data 8.
For study of cleaning ability of CFC alternative detergent for cleaning backside of parts, refer
to JERG-0-043-TM001 Technical Data 9.

5.3.4 Surface treatment materials of parts and printed wiring board
Surface treatment materials used to improve solderability (principally plating) shall conformwith the requirements of JERG-0-039, but the following requirements shall have precedence.
(1) The parts and printed wiring board shall be solder plated as follows except the casewhere Au-Sn solder alloy is used. Au plating (according to AMS 2422 and ASTM B488)
shall apply in the case of Au-Sn solder alloy etc.
a. Composition of plating – Sn 50%-Sn98% (Balance amount is Pb)
b. Thickness – 5 μm or morec. Method - Electrolytic plating shall be used as a rule. Hot dipping, fusing, or
electroless plating may be used provided that intermetallic compound is properly
formed with the base metal.
d. Parts with Au plated terminals shall be used after removing Au with the solder.
(2) In the case of parts and wiring board with Ag plated printed terminals, solder plating
shall not be directly applied and protection against leaching shall be considered.

[Reference]
For verification of the effect of the composition of plating of terminals on thermal fatigue
strength, refer to JERG-0-043-TM001 Technical Data 10.

- 20 -

JERG-0-043E(E)

5.4 Solder deposition
5.4.1 Solder deposition in total heating process
Deposition of solder paste on the wiring board shall be made by printing (screen printing or
stencil printing) or application by the dispenser. The following requirements shall be satisfied.
(1) The following points shall be established by the process specifications as required, andprocess control shall be provided for application of solder paste.
a. Temperature and humidity of the solder paste application processb. Printing conditions such as printing speed, printing pressure, penetration,clearance, parallelism of the wiring board, parallelism of squeeze, squeeze angle,
parallelism of the mask, and cleaning conditions.
c. Amount of solder fed and accuracy in printing(2) Attention shall be paid to the following points in handling the solder paste.
a. The solder paste shall be stored under the conditions specified in the material
standard and shall be consumed within the specified period.
b. A container of the solder paste shall be opened after leaving at room temperature
for the period recommended by the manufacturer (1 to 2 hours normally) after removalfrom the refrigerator in order to avoid absorption of moisture.
c. Mix well using the special mixer or mixing rod under constant temperature until
the specified viscosity is reached (in case of printing process).
d. If solder paste taken out from the container is used again, it shall be verified thatno problem is associated with reuse.
(3) Once solder paste is applied, installation of parts and soldering shall be made as
quickly as possible within a period recommended by the manufacturer.
(4) When the printing process is used to feed solder, the following points shall be satisfied.
a. Amount of solder fed shall be such that satisfactorily forms the shape of fillet
specified in paragraph 5.9.3.
b. For amount of solder fed and accuracy in printing, attention shall be paid to thefollowing points.
i) Application of the appropriate amount of the solder without omission, bleeding,overflow, and shortage shall be confirmed. (For feed amount of solder, thickness ofthe mask commonly used is indicated in Table 5-2)ii) For positioning accuracy of the print, absence of shift shall be confirmed.

- 21 -

JERG-0-043E(E)

Table 5-2 Solder feed amount (for reference)
The solder feed amount is determined according to the thickness of the metal mask
and the shape and dimensions of the opening of the mask.
Principal Parts

Solder Feed Amounti) For rectangular shaped passive parts
rectangular shaped with outside
dimensions 2.0 mm x 1.25 mm or more
having printed terminal or gull wingtype active parts with 0.5 mm or moreterminal pitch*150 to 200 mii) For power parts and large parts

200 to 300 miii) For the parts under both i) and ii)
categories on the same wiring
board

Solder feed amount shall be determined
after verification of quality and reliability ofthe solder joints.

*Note: As a result of the evaluation tests, it was confirmed that the thicker feed with theamount of 400 mm provides better quality for network resistors. (Refer to JERG-0-043TM001 Technical Data 11.)
(5) The following points shall be satisfied when an application by solder dispenser is
employed among the various types of solder feed methods.
a. In the case of the application by solder dispenser, the solder paste specific for solder
dispenser shall be used.
b. Solder feed amount is determined by the diameter of needle, discharge pressure andtime, and an equivalent amount to the amount of the printing method shall apply.
5.4.2 Solder deposition in local heating process
Methods for solder deposition in local heating are solder paste, solder preforms, solder wires,etc. In these cases, the following points shall be satisfied.
(1) Feeding method of solder paste shall conform to paragraph 5.4.1 of this standard.
(2) In feeding solder, the shape of the preform shall be basically the same as the shape ofthe land, and the amount shall be such that the shape of the fillet specified in paragraph5.9.3 of this standard shall be satisfied.
(3) Method of feeding solder wires shall conform to paragraph 5.7 of this standard.
[Reference]
For Verification of Solder Feeding and Shape of Solder Fillet, refer to JERG-0-043-TM001
Technical Data 11.
5.5 Feeding of adhesive for fixing of parts
When feeding adhesive for fixing of the parts is made, appropriate method from printing,transfer, or application by the dispenser shall be selected.

- 22 -

JERG-0-043E(E)－ NOTE －When the part is bonded on the wiring board, adhesive squeezed from thebottom of the part shall not cover the land of the board.

5.6 Installation of parts
To mount the parts on the board, automatic inserter, semi-automatic inserter, or manual
method can be used. In installing the parts, the following points shall be used as reference.
(1) In installing the parts, the checkpoints such as tooling, chipping-off, wear, or blockingof the nozzles of the automatic inserter and semi-automatic inserter, shall be establishedin the process specifications for the purpose of process control.
(2) For verification of the accuracy of parts installation, the following points shall be used
as reference. However, the ultimate accuracy of installation shall be as specified inparagraph 5.9.3l of this standard.
a. For accuracy of installation in the direction of part width or in the direction of thewidth of the lead (terminal) (x-direction), accuracy within ±10% or less against thewidth of the part or lead shall be verified visually or by appropriate magnification.
b. For accuracy of installation in the longitudinal direction of the part or in thelongitudinal direction of the lead (terminal) (y-direction), accuracy within ±10% or lessagainst the length of the part or lead shall be verified visually or by appropriatemagnification.
c. For the parallelism of parts installation (z-direction), accuracy within ±10° or lessshall be verified visually or by appropriate magnification.
d. For deformation of the solder paste due to installation of the parts, contact of all theterminals with the solder paste and appropriate terminal sinking (0 to 50 mm as
standard) shall be verified visually or by appropriate magnification, with Figures 5-2
and 5-3 as a reference.

- 23 -

JERG-0-043E(E)(1) Installation accuracy in x-direction(2) Installation accuracy in y-direction(3) Parallelism of installation in z-direction(4) Deformation of solder paste due toinstallation of the part

Figure 5-2 Installation accuracy of the parts (chip and other types)

Land

Lead
(1) Installation accuracy in x-direction(2) Parallelism of installation in z-direction(3) Deformation of solder paste due toinstallation of the part

Figure 5-3 Installation accuracy of the parts (gull wing lead type terminal)- 24 -

JERG-0-043E(E)

5.7 Soldering
Soldering preparation such as confirmation of the parts used and the tools used shall becomplied to JERG-0-039.
5.7.1 Total heating process
When the total heating method is used, the following points shall be satisfied.
(1) Temperature profiles for Sn63/Pb37, Sn60/Pb40, and Sn-Ag solder alloys are shown in
Figure 5-4 and Table 5-3 for reference.
By VPS method, the temperature profile shown in Figure 5-4 and Table 5-3 is difficult toattain because of the difficulty in regulating temperature increases, accordingly,
temperature profiles shall be determined after verification of the quality of solder joints.
(2) For the method of acquiring temperature profiles, use a dummy wiring board andthermocouples attached to the surface of the board, at the terminal of the part, and on thesurface of the part with the high temperature solder (melting point 300°C) or the adhesive
according to the detail requirements as follows.
a. For locations where the thermocouples are attached, measurements shall be madeat three or more points on the surface of the printed wiring board shown in Figure 5-5
unless there are any of the following problems.
b. Where a wiring board or parts having lower guaranteed temperatures for soldering
is used or a part with lower maximum allowable temperature for the parts or package
is installed, the temperature on the surface of the board, at the terminal of the part,and on the surface of the part shall be measured according to the configuration andfulfillment of the guaranteed maximum temperature for soldering shall be verified.
c. In particular, in case of the soldering method using infrared rays as primary heatsource, measurement shall be made very carefully because temperature distribution
on the wiring board is significantly affected by differences in the heat absorption rateand heat capacity of the parts.
(2) Control of the temperature profile shall be provided.

- 25 -

JERG-0-043E(E)－ NOTES －i) Depending on the flux contained in the solder paste, quality of solder joints
may significantly decrease due to abnormal reaction when the temperature
profile shown in Figure 5-4 and Table 5-3 is used. In such a case, the behavior insoldering shall be investigated using thermal analysis to determine temperature
profile suitable for the material concerned.
ii) Soldering by total heating process exceeding once shall not be applied as arule, other than the case where soldering by total heating is applied for both sidesof the wiring board once at each side or where soldering by local heating to mountadditional parts is applied. None the less, heat resistance of the parts and wiringboard used shall be considered even when soldering by total heating is applied forboth sides of the board, once at each side or when soldering by local heating tomount additional parts.
iii) The applicable range of the heat resistance in soldering is limited to the leadin the case of parts with leads. Some parts have different maximum allowabletemperature of the package and maximum temperature in soldering. Maximum
allowable temperature of the package shall be confirmed for respective parts.
iv) Where a terminal of the part and attachment land having large area aresoldered using solder paste, care shall be taken to provide a relief for thevaporized flux because void is easily generated.

[Reference]
For verification of the reliability of solder Joints by repeated reflow processes, JERG-0043-TM001 Technical Data 12.

- 26 -

JERG-0-043E(E)

Table 5-3 Temperature profile for reference by total heating process
Item

Specific Detail

I

Heat build-up period forpreheating

The preheating temperature shall be reached atconstant rate within 30 to 60 seconds continuously withthe heat rate of 2.0°C to 5.0C/sec.

II

Preheating period

Preheating temperature shall be maintained for 60 ±30 seconds at 150°C  10C. However, this preheating
period may be extended within this range when a voidis generated in the solder joint.

III

Heat build-up period for
actual heating

The actual heating temperature shall be reached atconstant rate within 20 to 40 seconds continuously withthe heat rate of 2.0°C to 5.0C/sec.

IV

Actual heating period(1) In addition to verification of absence of poor wettingwith solder and breakage of the parts due to heat, thefollowing requirements shall be satisfied.
(2) For Sn63/Pb37 or Sn60/Pb40 solder alloys, 30 to 60
seconds at 200C or above, and the peak temperatureshall be 240C or below.
(3) For Sn-Ag solder alloys, 30 to 60 seconds at 210Cor above, and the peak temperature shall be 255C or
below.

Cooling period

Cooling shall be made continuously.

Temperature (C)V

Thermocouple

Time(Minute)Transfer Direction

Figure 5-4 Temperature profile for reference- 27 -

Figure 5-5 Location of thethermocouples for acquiring
temperature profile

JERG-0-043E(E)5.7.2 Local heating process
Where the local heating method is used, the following requirements shall be satisfied. Whenmethods other than this are used, appropriate evaluation shall be made in advance.
(1) The procedure for hand soldering shall conform to the requirements of JERG-0-039,
except the followings.
a. In feeding the solder, an appropriate amount of solder shall be melted with thesoldering iron in contact with the land and with the solder in contact with the land;
quickly remove the soldering iron when solder is melted.
b. The chip of the soldering iron shall be placed on the surface so that temperature of
the surface to be joined reaches the temperature for soldering as quickly as possible.
c. When heat capacity of the soldered section is large, a hot plate shall be used as theauxiliary heat source.

－ NOTES －For hand soldering of multilayer ceramic capacitors, take care regarding the following
matters.
i) Make the soldering iron touch only the land of printed circuit board and do
not let it touch the electrodes of the multilayer ceramic capacitor.
ii) When soldering, pre-heating the circuit board and multilayer ceramic
capacitor using a hot plate and spot heater, etc. is recommended.
iii) After the soldering, avoid rapid cooling.

(2) Where laser soldering or light beam soldering is used, the section to be heated shallbe limited to the section where the solder is fed, and the beam shall not irradiate the partor leads other than the solder. However, when the geometry of the terminals of the part is
not a lead type and does not satisfy the condition for soldering above, a dummy land shallbe provided for irradiation by the beam because damage of the part due to leaching may
be possible.
(3) Where pulse heat soldering is used, the following points shall be satisfied.
a. Equipment and soldering condition suitable for configuration of the work shall beestablished and used.
b. When the heat capacity of the work is large, a hot plate shall be used as the auxiliaryheat source so that temperatures as low as possible and soldering time as short as
possible can be established as the soldering condition.
[Reference]
For verification of soldering condition by local heating process and reliability of the solder
joints, refer to JERG-0-043-TM001 Technical Data 13.

- 28 -

JERG-0-043E(E)5.8 Cleaning and cleanliness test
5.8.1 Cleaning(1) Soak cleaning, ultrasonic cleaning, shower cleaning, and brush cleaning methods areavailable and the cleaning methods and conditions that will not adversely affect thematerials of the wiring board or parts and satisfy the cleanliness specified in paragraph5.8.2 shall be selected.
(2) When aqueous cleaners are used, adequate rinsing with deionized water (10 km ormore) and complete drying shall apply.
－ NOTES －i)

Ultrasonic cleaning shall not be used for assemblies on which electronicparts such as ICs, diodes, transistors are mounted.
ii)

Do not Clean with the detergents that will affect the parts shown in

JERG-0-043-TM001 Technical Data 14.
iii)

Cleaning shall apply as quickly as possible after soldering is complete.

[Reference]
For assessment of wash solvent resistance with respect to parts and materials, refer to JERG0-043-TM001 Technical Data 13.
5.8.2 Cleanliness test
(1) Cleanliness test is performed in order to monitor effectiveness of cleaning of the board
assembly after soldering. The board assembly designated shall be tested before
application of conformal coating.
(2) Test method employed shall be either of the following as a rule.
a. Resistivity of the solvent extract
b. Sodium chloride (NaCl) equivalent ionic contamination test(3) When ionic residues locally present cannot be detected by the above test methods (e.g.,
extraction is impossible by NaCl equivalent ionic contamination test due to configurationof the part), ion chromatographic method shown in paragraph 5.8.2(7) is effective.
(4) Allowable limit
Within the range shown in Table 5-4.
Table 5-4 Allowable limit for cleanliness test
Test Method

Initial Value

Final Value

Resistivity of Solvent Extract

60 km

20 km or more

200 kmLess than 1.55 g/cm2(10.0 g/in2)

Sodium Chloride Equivalent Ionic
Contamination Test

- 29 -

JERG-0-043E(E)(5) Resistivity of solvent extract
Resistivity of the solvent extract shall be measured as follows.
a. The test solution shall be 75% isopropyl alcohol and 25% deionized water by volume.
This solution shall be passed through the mixed bed de-ionizing cartridge. Resistivityof the solution after passing through the cartridge shall exceed 60 km .
b. A funnel, washing bottle, and a container shall be washed using the test solution.
The test solution shall be prepared in an amount at 1.55 ml/cm2(10 ml/in2) for the areaof board assembly at both sides.
c. The test solution shall be slowly poured over both sides of the board until the
prepared amount is consumed.
d. Resistivity of this extract shall be measured using a resistivity meter.
(6) Sodium chloride equivalent ionic contamination test
Sodium chloride equivalent ionic contamination test shall be conducted as follows.
a. The test solution shall be 75% isopropyl alcohol and 25% deionized water. It shall bechecked out that the composition of the test solution is correct at the beginning of thetest and at 4-hour intervals. If fluctuations in composition check data are small and do
not adversely affect the test result, the interval periods may be extended.
b. The equipment used shall be calibrated at the same interval with the interval forcomposition check of the test solution using the reference solution with known amountof NaCl.
c. Initial and standard purity of the test solution shall exceed 200 km prior tomeasurement of each sample.
d. The automated device for conducting this test is available in the market and may be
used. Such deice is recommended when control of cleaning is made continuously. This
device will indicate amount of NaCl per rectangular inch in micrograms, and in orderto obtain accurate result, careful calibration shall be made for individual flux.
(7) Ion chromatographic method
Measurement by ion chromatographic method shall be made as follows.
a. Drop 30 ml of deionized water (200 km or more) using a syringe on the surface of
the wiring board where a part is removed.
b. Rub the section of the part stripped from the board against the section of the board
from which the part is removed, and dissolve the residues in deionized water (200 km
or more).
c. After dissolving for 5 minutes, suck up the deionized water (200 km or more) usinga syringe and add deionized water (200 km or more) to make 50 ml solution.
d. Inject the solution of (c) above into the ion chromatography instrument formeasurement.
[Reference]
For Verification of the Evaluation Method of Wiring Board Cleanliness, refer to JERG-0-043TM001 Technical Data 15.

- 30 -

JERG-0-043E(E)5.9 Quality assurance
5.9.1 Records
The following records shall be made available.
(1) Process control record of solder feeding(2) Process control record of parts installation(3) Process control record of adhesive feeding for fixing of parts(4) Process control record of soldering.
(5) Record of cleaning and cleanliness test(6) Record of visual inspection(7) Record of operators and inspectors qualification(8) Record of environmental conditions (temperature and humidity)(9) Calibration record of manufacturing and inspection tools and equipment(10) Record of dehumidification of wiring boards (assembly)
5.9.2 Inspection
The following inspections shall be made at appropriate stages in the processes.
(1) Visual inspection(2) Non-destructive testing(3) Functional test(4) Cleanliness test
5.9.3 Visual inspection
The requirements for surface mounting are as follows. Other than those provided below shallbe in accordance with JERG-0-039.
Visual inspection shall be made for all the solder joints and the peripheries using Inspection
Magnification shown in Table 5-5. When result of inspection using the Inspection
Magnification of Table 5-5 is doubtful, acceptance shall be determined using the Acceptance
Judgment Magnification in Table 5-5. Higher magnification shall be used as necessary.
For acceptance criteria in visual inspection of solder joints shall be in accordance with (1) and(2) below and J-STD-001*S.
Table 5-5 Magnification for visual inspection
Objects of Inspection

Inspection
Magnification

Acceptance
Judgment
Magnification*

Surface Mounting

10x

20x

Surface Mounting (Pitch 0.65 mm or less)

20x

40x

* When result of inspection using the Inspection Magnification is doubtful,acceptance shall be determined using the Acceptance Judgment
Magnification.

- 31 -

JERG-0-043E(E)(1) Acceptance criteria
a. As a rule surface of the solder shall be shiny and smooth. However, dull surface dueto oxidization film on smooth solder joints is acceptable.
b. For solder joints of the part of which the height of the terminal is large like tantalum
capacitor, discontinuity of the curvature of the surface may be formed at the point
where solder fillet formed from the terminal of the part and the solder fillet formed
from the land meet and it may look that a line is formed, but such joint is acceptable.
c. The complete wetting by solder shall be established.
d. Shape of the solder fillet shall comply with the shape specified in Tables 5-6 through
5-14.
(2) Rejection criteria
Conditions as shown below are inappropriate solder joints and constitute a ground forrejection if any one of such conditions applies.
a. Scorching, burning, melting of the part and leaching of the terminalb. Scorching of the wiring board material and separation of the conductor
c. Presence of dropping out of the part unsecured lead, dislocation, and Manhattanstyle construction of the parts
d. Un-melted solder, non-wetting by solder, bridging and solder ballUnless special provision is applicable to the foreign substances, stationary substance(will not move by external force applied with a stick etc.) of which dimension deductedfrom the minimum distance between patterns satisfies minimum required conductor
spacing may be acceptable when coating is applied.
e. Cracks in the solder joints
f. Flux residues after cleaning
However, very small amount of flux residues that can be demonstrated harmless basedon the evaluation data of the electrochemical migration resistance test according to
objective evidence and technical judgment, can be excluded.
[Reference]
For the relationship between solder fillet shape and service life, refer to JERG-0-043TM001 Technical Data 16.
For comparisons of acceptance criteria for visual inspection, refer to JERG-0-043-TM001
Technical Data 22.
For acceptance criteria in visual inspection of solder joints, refer to JERG-0-043-TM001
Technical Data 23.

- 32 -

JERG-0-043E(E)

Table 5-6 Visual inspection criteria for soldering of chip parts
FeatureDim.

Requirements

Max. Side OverhangA

0.25 W or 0.25 P whichever is less. Minimum
space between electrodes shall be maintained.

End Overhang(Not indicatedin the sketch)B

Not permitted

Min. End Joint WidthC

0.75 W or 0.75 P whichever is lessMin. Side Joint LengthD

0.75 T or 0.13 mm whichever is lessMax. Fillet HeightE

Fillets may be formed on electrodes but shall notextend beyond the electrode to the body of thepart.

Min. Fillet HeightF

0.3 H or 1 mm whichever is lessSolder Thickness

G

0 to 0.3 mm

Electrode Thickness

H

Value specific to the partJ

Overlap shall be maintained.

Width of LandP

Design value

Electrode Width

W

Value specific to the partMax. Installation Gradientθ

10°Min. Land
Overlap

andElectrode

Parts
Solder

SolderFigure 5-6 Chip parts- 33 -

JERG-0-043E(E)

Table 5-7 Visual inspection criteria for soldering of L-leaded parts
FeatureDim.

Requirements

Max. Side OverhangA

0.25 W or 0.25 P whichever is less. Minimum
space between terminals shall be maintained.

Max. Toe Overhang (Notindicated in the sketch)B

Not permitted

Min. End Joint WidthC

0.75 W or 0.75 P whichever is lessMin. Side Joint LengthD

0.75 LMax. Fillet HeightE

H+G, Solder shall not be in contact with the bodyof the part.

Min. Fillet HeightF

0.3 H or 1 mm whichever is lessSolder Fillet Thickness

G

0 to 0.3 mm

Lead height

H

Value specific to the partMin. Land Extension

K

0.5 H or 0.5 mm whichever is lessLead Length

L

Value specific to the part

Land Width

P

Design value

Land Length

S

Design value

Lead Width

W

Value specific to the part

Source: J-STD-001

Figure 5-7 L-Leaded parts- 34 -

JERG-0-043E(E)

Table 5-8 Visual inspection criteria for soldering of bottom terminal parts
FeatureDim.

Requirements

Max. Side OverhangA

Minimum spacing between electrodes shall bemaintained.

End Overhang

B

Not permitted

Min. End Joint WidthC

0.75 W or 0.75 P whichever is lessMin. Side Joint LengthD

Satisfactory fillets shall be formed.

Solder Thickness

G

While height is not specified, satisfactory fillet shallbe formed.

Land
and
Overlap

J

Overlap shall be maintained.

Land Width

P

Design value

Electrode Width

W

Value specific to the part

Electrode

Source: J-STD-001

Figure 5-8 Bottom terminal parts- 35 -

JERG-0-043E(E)

Table 5-9 Visual inspection criteria for soldering of LCC parts
FeatureDim.

Requirements

Max. Side OverhangA

0.25 W. Minimum spacing between terminals shall bemaintained.

End Overhang

B

Not permitted

Min.
End
Width

Joint

C

0.75 W

Min. Side
LengthJoint

D

Depth of castellation

Max. Fillet HeightE

The maximum fillet may extend past the top of thecastellation provided it does not contact the body.
Does not violate minimum electrical clearance.

Min. Fillet HeightF

G + 0.5 H

Solder Thickness

G

Wetting shall be evident.

Electrode Height

H

Value specific to the part

Land Length

S

Design value

Electrode Width

W

Value specific to the part

Source: J-STD-001

Figure 5-9 LCC parts- 36 -

JERG-0-043E(E)

Table 5-10 Visual inspection criteria for soldering of J-leaded parts
FeatureDim.
Requirements
Max. Side OverhangA
0.25 W. Minimum spacing between terminals shall bemaintained.
Max. Toe OverhangB

0.25 W

Min. End Joint WidthC

0.75 W

Min. Side Joint LengthMax. Heel Fillet Height

D
E

Min. Heel Fillet HeightF

1.5 W or 0.7 J whichever is lessSolder shall not be in contact with the body of the
package.
Points where the lead starts to deflect shall bereached. Heel fillets shall be formed.

Max. Solder Thickness

G0.75 mm

Lead Thickness

T

Value specific to the part

Lead Width

W

Value specific to the part

Source: J-STD-001
J

Figure 5-10 J-Leaded Parts- 37 -

JERG-0-043E(E)

Table 5-11 Visual inspection criteria for soldering of gull wing lead parts
FeatureDim.
Requirements
Max. Side OverhangA
0.25 W or 0.5 mm whichever is lessMax. Heel Fillet HightE
The solder fillet may span the bend of
the lead shoulder.
Solder shall not contact with component
molds or seals. Surface mountcomponents with 42 alloy or similar
metal leads shall not have solder
extending below the body.
Max. Solder ThicknessG
2T
Max. Lead DeflectionJ
3T[Reference]
For maximum heel fillet height of gull wing leaded terminal parts, refer to JERG-0-043-TM001
Technical Data 27.
Lead
Lead

Land

Lead
Solder

Lead

Land

Land

Lead

Land

Land
Lead

Land

Judgment criteria figure for locations A, G, and J

Judgment criteria figure for location E①: See the required values for E in Table 5-11.
Source of E location: J-STD-001

Figure 5-11 Gull wing lead parts－ NOTES －For ①, the case where the solder is unavoidably raised during reflow is assumed.

- 38 -

JERG-0-043E(E)

Table 5-12 Visual inspection criteria for soldering of MELF parts
FeatureDim.

Requirements

Max. Side OverhangA

0.25 W or 0.25 P whichever is less. Minimum spacing
between electrodes shall be maintained.

End Overhang

B

Not permitted

Min. End Joint Width

C

0.5 W or 0.5 P whichever is less

Min.
Side
LengthD

0.75 R or 0.75 S whichever is less. Not applicable to parts
with electrodes at the side only.

Max. Fillet HeightE

Fillets may be formed on electrodes but shall not extend
beyond the electrode to the body of the part.

Min. Fillet HeightF

G+0.25W or G+1.0mm, whichever is lessSolder Thickness

G

Wetting shall be evident.

Land and Electrode
OverlapJ

0.75R. Not applicable to parts with electrodes on the side
only.

Land Width

P

Design Value

Electrode Length

R

Value specific to the part

Land Length

S

Design Value

Electrode Diameter

W

Value specific to the part

Joint

Source: J-STD-001

Figure 5-12 MELF parts- 39 -

JERG-0-043E(E)

Table 5-13 Visual inspection criteria for soldering of plate electrode parts (diode parts)
FeatureDim.

Requirements

Max. Side OverhangA

As specified in Chip part (Table 5-6)

Max. End OverhangB

As specified in Chip part (Table 5-6)

Min. Joint WidthC

As specified in Chip part (Table 5-6)

Max. Fillet HeightE

As specified in Chip part (Table 5-6)

Min. Fillet HeightF

G+0.25H or G+0.5mm, whichever is lessSolder ThicknessG

As specified in Chip part (Table 5-6)

Electrode Height

H

Value specific to the part

Land and Electrode Overlap

J

As specified in Chip part (Table 5-6)

Land Width

P

Design value

Electrode Width

W

Value specific to the partMax. Installation GradientθAs specified in Chip part (Table 5-6)

[Reference]
For the solder joint appearance criteria for plate electrode parts (diode parts), refer to JERG0-043-TM001 Technical Data 24 and 25.

W

Ｐ
Figure 5-13 Plate electrode parts (diode parts)- 40 -

JERG-0-043E(E)

Table 5-14 Visual inspection criteria for soldering of stacked capacitor parts
FeatureDim.

Requirements

Max. Side OverhangA

0.25 W or 0.25 P whichever is less. Minimum
space between electrodes shall be maintained.

Max. Toe Overhang

B

Minimum space between electrodes shall bemaintained.

Min. End Joint WidthC

0.75 W or 0.75 P whichever is lessMin. Side Joint LengthD

0.75 LMax. Fillet HeightE

Lower surface of Capacitor

Min. Fillet HeightF

G+T

Solder Fillet Thickness

G

Wetting shall be evident

Lead height

H

Value specific to the partMin. Land Extension

K

Design value. Value specific to the part

Lead Length

L

Value specific to the part

Land Width

P

Design value

Land Length

S

Design value

Lead Width

W

Value specific to the part

Lead Thickness

T

Value specific to the part

[Reference]
For the solder joint appearance criteria for stacked capacitor parts (diode parts), refer to
JERG-0-043-TM001 Technical Data 24 and 25.

(Lower Surface)

Figure 5-14 Stacked capacitor parts- 41 -

JERG-0-043E(E)5.9.4 Nondestructive inspection
Appropriate nondestructive inspections, such as X-ray inspections, shall be conducted where
specified by the contract documents or as required to verify that no defect detrimental to theperformance is present.
5.9.5 Functional test
After completion of inspections under paragraphs 5.9.3 and 5.9.4, electrical inspections shallbe conducted to verify that no anomalies are present.
5.9.6 Cleanliness test
After cleaning, no contamination and flux residue shall be found when inspected visually.
Where a cleanliness test after cleaning is specified in the technical documents, the test
specified in paragraph 5.8.2 shall be successfully conducted and the results shall meet therequirements.
5.10 Rework of Solder Joint(1) Rework of solder joints shall be classified as follows depending on the configuration of
the terminals of the part.
a. Chip parts:
As a rule, local soldering shall be applied after replacement with the new parts.
b. Lead parts:
Local soldering shall be applied after removing solder at the joint and on the leadterminal. The part may be used without replacement if no problem is detected when
quality is checked.
(2) Rework of the solder joint shall be made in appropriate conditions according to the
local heating process specified in paragraph 5.7. As a rule, only one cycle of rework shallbe applied at the same location. (See JERG-0-043-TM001 Technical Data 17. One cycle ofrework shall consist of a removal of solder and a re-soldering) Rework shall be made inaccordance with paragraph 5.6.5 (Rework) of JERG-0–039.
The further rework can be made if the Reliability Evaluation Data proves that there will
not be any problems.
－ NOTE －Because solder lands are easily detached and removed, adequate care shallbe taken in removing solder with a solder wick not to move the soldering ironmore than necessary.

- 42 -

JERG-0-043E(E)5.11 Evaluation and Judgment of Service Life of Solder Joint
Evaluation method and acceptance criteria for the test method and conditions specified inparagraph 4.4.2 are as follows.
5.11.1 Evaluation and judgment by visual inspection
Visual inspection criteria shown in Table 5-15 shall be satisfied.
Table 5-15 Evaluation and criteria for visual inspections
Item

Specific Details(1) Procedure for
Thermal Shock Test

Thermal shock tests shall be conducted according to the test
method and conditions specified in paragraph 4.4.2.
a. Sample- The material of the surface mount wiring board, configurationof solder land, and the mounted parts of the sample shall beequal to those used for the actual electronic device. Soldering
shall be made using the same equipment, conditions, andmaterials with those used for the actual production of theelectronic devices.
- Evaluations shall be made for the respective parts. (It is
recommended that the number of solder joints to be evaluatedshould be n = 50 or more per part from the accuracy point of viewin determination of service life.)b. Preparation of the sample- Flux remaining on the surface of solder joints shall be cleaned
before the inspection to facilitate easy detection of surface cracks
in the solder.

(2) Procedure andEvaluation Method andCriteria for Visual
Inspection

Visual inspections shall be made using appropriate magnification.
a. Sampling rate for visual inspections- Sampling rate shall be 100 cycles or less from accuracy pointof view of inspection.
b. Evaluation and judgment criteria for surface cracks in thesolder- Evaluation of surface cracks in the solder shall be madeaccording to the class of the level specified in Table 5-18. Surface
clack level class 4 shall be judged unacceptable.

(3) Weibull Analysis,
Evaluation, andDetermination Criteria
for Service Life

Analysis shall be made for cracks classified as surface crack levelclass 4 using Weibull Probability Plotting Paper.
It shall be confirmed that the characteristic life (η) satisfies 500
cycles.

- 43 -

JERG-0-043E(E)5.11.2 Evaluation and judgment of crack depths
Evaluation of crack depth as shown in Table 5-16 shall be conducted, and the criteria shall besatisfied.
Table 5-16 Evaluation and criteria for crack depths
Item
Specific Details(1) Procedure for Thermal
Thermal shock tests shall be conducted according to the test
Shock Test
method and conditions specified in paragraph 4.4.2.
a. Sample- Same as under paragraph 5.11.1.
b. Preparation of the sample- Same as under paragraph 5.11.1.
(2) Procedure for
Crack depth shall be measured by cross-section observation of
measurement of Crack Depth the sample after completing 500 cycles.
a. The center of the solder joint shall be cut, and the section
shall be prepared by polishing or etching the surface for themeasurement of crack depth using an appropriate optical
microscopy.
b. The number of sections of the solder joint to be inspectedshall be n = 10 or more for each part taking variance in thesamples and preparing sections.
(3) Evaluation Method and- The evaluated crack depth shall be classified according to the
Criteria
crack depth level class specified in Table 5-19. Cracks classified
as crack depth level class 3 or higher shall be determinedunacceptable, and all the solder joints inspected shall beclassified as crack depth level class 0, 1 or 2.

5.11.3 Evaluation and judgment by electrical characteristics
Inspection and evaluation of electrical characteristics as shown in Table 5-17 shall be
conducted, and the criteria shall be satisfied.
Table 5-17 Evaluation and criteria for electrical characteristics
Item
Specific Details(1) Procedure for Thermal
Thermal shock tests shall be conducted according to the test
Shock Test
method and conditions specified in paragraph 4.4.2.
a. Sample- Same as under paragraph 5.11.1.
b. Preparation of the sample- Same as under paragraph 5.11.1.
(2) Procedure for ElectricalInspection of electrical characteristics of solder joints shall beCharacteristics Evaluation
conducted at both normal and test temperatures after
completing 500 cycles.
(3) Criteria
No anomalies shall be detected when conductive resistances
before and after the test are compared.

- 44 -

JERG-0-043E(E)

Table 5-18 Crack level class on solder surface based on visual inspection(chip type parts)
Surface Crack Level Class

Typical Example

Wrinkles and cracks shall not
be observed on the surface ofsolder fillets.
1

2

Wrinkles that are not deep
enough to be consideredcracks are observed on thesurface of the solder fillet(especially the boundary
between the part terminaland solder).

The length of cracks on thesolder fillet surface must be
less than 1/2 of the component
width.
3

The length of crack on thesolder fillet surface must be
longer than 1/2 of thecomponent width.
4- 45 -

Table 5-19 Crack depth level class of solder joints
Class

0

1

2

3

- 46 -

Principal Configuration of Parts

1

No cracks are observed in thesolder

X < 2/3a2/3a  X < 4/5a
X  4/5aY < 2/3b
2/3b  Y < 4/5b
Y  4/5b
Z < 2/3c
2/3c  Z < 4/5c
Z  4/5cAnyconditionof either X, Y, or
Conditions for all X, Y, and Z Conditions for all X, Y, and Z
Z is satisfied.
are satisfied.
are satisfied.

2

No cracks are observed in thesolderX  4/5aY  4/5b
Conditions for all X and Y aresatisfied.

X < 2/3a2/3a  X < 4/5a
Y < 2/3b
2/3b  Y < 4/5b
Conditions for all X and Y are Any condition of either X or Y issatisfied.
satisfied.

JERG-0-043E(E)Appendix I Terms and definitions
Terms and definitions used in this standard are as follows:(1)

Crack (or Solder Crack)

Fissure of the material. In this standard, a phenomenon that occurs by generation of thermal
stresses in the solder joint due to differences in the coefficient of thermal expansion between
the wiring board, parts, and solder alloy.
(2)

Eutectic Structure

A mixture of more than one crystalline substance produced by solidification of the mixture ofsuch substances in the liquid phase when the mixture is gradually cooled. In the case of Sn
and Pb alloy, 62.7Sn-37.3Pb produces the eutectic system, and at the temperature of 183C,
the alpha phase (Pb) and beta phase (Sn) crystallize simultaneously, and the eutectic structure
is formed.
(3)

Finite Element Method (FEM)

One of the structural and strength analysis methods using computer simulations.
(4)

Gull Wing Lead

A surface mount part lead that flares outward from the part body.
(5)Intermetallic Compound

An alloy phase formed between the solder alloy and material of the conductor and has aharder and more brittle property than the original metals. Between Sn and Cu in the solder
joints, intermetallic compounds consisting of the epsilon phase (Cu3Sn) and the eta phase(Cu6Sn5) are formed.
(6)

Land

A portion of a conductive pattern usually, but not exclusively, used for connection or
attachment, or both, of parts. Square lands are principally used for the connection to surface
mount parts, and round lands are used for parts with leads.
(7)

Laser Soldering

A type of reflow soldering method where the Nd:YAG laser or CO2 laser is used as the heatsource. The Nd:YAG laser is principally used as the heat source as non-contact type heat sourcein the surface mount method.

I-1

JERG-0-043E(E)(8)

LCC (Leadless Chip Carrier)

A surface mount package component without leads, and the pads are arranged on the side of
the package. (Usually a ceramic package IC)(9)

Leaching

A phenomenon where components of the material joined with solder diffuses into the solder
alloy partially or totally, which results in erosion of the material.
(10) Light Beam Soldering
A method of soldering where energy generated by the concentration of reflected light at thesecond focal point irradiated from a light source such as xenon arc lamp located at the first
focal point of the elliptical mirror is used. Features of non- contacting rapid and local heating
can be achieved.
(11) Marginal Life (or Failure Time)Time duration from start of the operation of the device or equipment to a failure. In thisstandard, marginal life is defined as the number of cycles to the first occurrence of an open
circuit detected by the electrical inspection.
(12) MELF (Metal Electrode Face)
A surface mount part with a cylindrical shape.
(13) Migration (or Electrochemical Migration)
Migration is a phenomenon, a special instance of electrochemical corrosion, where the metalcomponent transfers from the cathode to the anode when the potential difference is applied
between the electrodes in humid conditions. Typical example is migration of Ag solder.
(14) Orange peel
The state of the solder surface with either of the following appearances: roughness, significant
irregularities, presence of spots, and presence of striations.
(15) Residue
Substances of solder or flux that adhere and remain on the wiring board, conductors, resist,and parts mounted on the board, and may cause failure.
(16) Rework
The reprocessing of articles or material that will make it conform to drawings, specifications,and contract.

I-2

JERG-0-043E(E)(17) Scale Parameter ()One of the parameters in the Weibull Analysis. Scale parameter is the time duration (life)
when 63.2% of total samples fail in the analysis using the Weibull probability paper frequently
used in the reliability data analysis, whatever the type of failure. In this standard, the Weibull
analysis is conducted for the number of failures in the visual and electrical inspections.
(18) Solder Paste
A material where the solder powder is mixed in the flux material in the emulsion state, andvarious additives are added to prevent separation of the solder powder and flux and to add
viscosity to the paste, thixotropic effect, and printability.
(19) Thermal StressStresses introduced by nonuniform temperature distribution or temperature change in a
structure or material which is constrained against expansion or contraction due to the external
constraints.
(20) Thick Film ElectrodeConductors or terminals formed by baking in atmospheric air or inert gas atmosphere after
the paste of Ag-Pd, Cu, etc., is coated, sprayed, or printed principally on the ceramic wiringboard.
(21) VPS (Vapor Phase Reflow Soldering)
The reflow soldering method where the latent heat of condensation generated

from theheating medium, such as inert organic solvent heated to evaporation when its vapor
condenses.
(22) X-ray Micro Analyzer
One of the surface analysis methods where low energy electrons are injected onto the solid
surface and identification of the elements present on the solid surface is made by detecting Xrays generated from the surface in return.

I-3