JERG-0-054B(E)General

STANDARD FOR BGA/CGA MOUNTINGPROCESS FOR SPACE USE

May 8, 2023

Japan Aerospace Exploration Agency

JERG-0-054B(E)This is an English translation of JERG-0-054B 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, Japani

JERG-0-054B(E)

TABLE OF CONTENTS
1. GENERAL ...................................................................................................................................1
1.1 Purpose ......................................................................................................................................1
1.2 Scope ..........................................................................................................................................1
1.3 Tailoring ....................................................................................................................................3
2. RELATED DOCUMENTS .........................................................................................................3
2.1 Applicable documents ...............................................................................................................3
2.2 Reference documents................................................................................................................4
3. TERMS AND DEFINITIONS ....................................................................................................6
4. GENERL REQUIREMENTS .....................................................................................................7
4.1 General ......................................................................................................................................7
4.2 Training and certification ........................................................................................................7
4.3 Design requiremants ................................................................................................................7
4.4 Process certification tests ........................................................................................................7
4.4.1 Vibration/shock tests .............................................................................................................7
4.4.2 Thermal shock tests ..............................................................................................................8
4.4.3 Electrochemical migration test ............................................................................................8
4.5 Manufacturing conditions ........................................................................................................8
4.5.1 General ...................................................................................................................................8
4.5.2 Manufacturing environment ................................................................................................8
4.5.3 In-process storage and handling ..........................................................................................84.5.4 Electrostatic discharge control .............................................................................................9
4.6 Quality assurance .....................................................................................................................95. APPROACH TO QUALITY ASSURANCE IN BGA/CGA MOUNTING ............................... 10
5.1 Definition of process assurance .............................................................................................10
5.1.1 Design and process verification ..........................................................................................10
5.1.2 Manufacturing process confirmation ................................................................................. 11
5.1.3 Product inspections .............................................................................................................12
6. EXAMINATION ITEMS AND INSPECTION METHODS FOR THE ESTABLISHMENT
OF A BGA/CGA MOUNTING PROCESS .............................................................................. 13ii

JERG-0-054B(E)

6.1 Examination items in board and mount structural design ................................................. 13
6.1.1 Points to consider when selecting the PWB ...................................................................... 13
6.1.2 PWB design ..........................................................................................................................14
6.1.3 Structural design .................................................................................................................16
6.1.4 Points to consider regarding mounting design.................................................................. 17
6.2 Examination items in mounting............................................................................................17
6.2.1 Mounting materials .............................................................................................................17
6.2.2 Soldering mounting .............................................................................................................17
6.2.3 Cleaning ...............................................................................................................................21
6.2.4 Staking and fixing ...............................................................................................................21
6.2.5 Coating .................................................................................................................................23
6.3 Inspections ..............................................................................................................................24
6.3.1 Visual inspection .................................................................................................................24
6.3.2 Nondestructive inspection ..................................................................................................25
6.3.3 Destructive inspection.........................................................................................................28
6.4 Reliability evaluation .............................................................................................................29
6.4.1 Evaluation sample ...............................................................................................................29
6.4.2 Reliability verification program .........................................................................................30
6.4.3 Electrochemical migration test (insulation reliability test) ............................................. 35
7. CONTROL ITEMS IN BGA/CGA PRODUCTS PRODUCTION ........................................... 36
7.1 Parts management .................................................................................................................36
7.1.1 Receiving inspection ............................................................................................................36
7.1.2 Storage .................................................................................................................................36
7.2 Control items in mounting and the standards for the items............................................... 36
7.2.1 Soldering mounting .............................................................................................................36
7.2.2 Cleaning ...............................................................................................................................38
7.2.3 Staking and fixing ...............................................................................................................38
7.2.4 Coating .................................................................................................................................38
7.3 Product inspections ................................................................................................................39
7.3.1 Visual inspection .................................................................................................................39
7.3.2 X-ray inspection ...................................................................................................................39
7.4 Storage and transportation....................................................................................................40
8. REWORK ..................................................................................................................................40iii

JERG-0-054B(E)Appendix I Terms and definitions............................................................................................ I-1

LIST OF FIGURES
Figure 6-1 Pad design image ....................................................................................................... 15
Figure 6-2 Solder resist designs applied to the pads ................................................................. 15
Figure 6-3 Examples of fixing using corner staking .................................................................. 16
Figure 6-4 Examples of observations of the exterior appearance ............................................. 25
Figure 6-5 Definition of the void ratio (BGA) ............................................................................. 27
Figure 6-6 Definition of the void ratio (CGA) ............................................................................. 27
Figure 6-7 Definition of the void ratio in the case that multiple voids exist (BGA/CGA)(calculate the void ratio from the sum total of the void area) ................................................... 28
Figure 6-8 Reliability verification program flowchart ............................................................... 31

LIST OF TABLES
Table 1-1 BGA/CGA structure and characteristics ...................................................................... 1
Table 6-1 Materials used in the PWB and examples of their characteristic values ................ 13
Table 6-2 Visual inspection items and criteria for BGA/CGA ................................................... 24
Table 6-3 X-Ray inspection items and criteria for BGA/CGA ................................................... 26
Table 6-4 Electrical tests .............................................................................................................. 32
Table 7-1 Visual inspection items and criteria for BGA/CGA ................................................... 39
Table 7-2 X-Ray inspection items and criteria for BGA/CGA ................................................... 40iv

JERG-0-054B(E)

1. GENERAL
1.1 Purpose
This standard applies to the mounting of BGA/CGA (Ball Grid Array/Column Grid Array) on
spacecraft such as launch vehicles and artificial satellites and the equipments installed onsuch spacecraft (hereinafter referred to as the “Spacecraft”) and the purpose is to establish amounting process and carry out quality assurance to minimize the risks in relation to quality
and reliability that arise from mounting.
1.2 Scope(1) This standard shows the requirements for design, mounting and inspection of theprinted wiring boards (hereinafter referred to as “PWBs”) that are necessary to obtainhighly reliable electrical connections for BGA/CGA, which are new terminal shapes thatcannot be handled with JERG-0-043.
(2) This standard shall apply to cases prescribed in the contractual specifications. In such acase, this standard shall apply to both the supplier and their subcontractors responsible for
performing parts of the contract. However, when the mounted PWB specified in thecontract is lead through mounting, surface mounting or the mixed type with BGA/CGA,
apply JERG-0-039 to the inserted mounting and apply JERG-0-043 to the surface
mounting except for the BGA/CGA.
(3) When applying BGA/CGA, an implementation process and set production control items
shall be established in accordance with the provisions of this standard.
(4) Table 1-1 shows the structure and characteristics of BGA/CGA defined as the scope of
application in the N/C edition and A edition of this standard as reference.

- 1 -Table 1- 1-1 BGA/CGA structure and characteristics
Manufacturer

XilinxMicrosemi

Model name
BGA/CGA
Column/ballcomposition

CF1140CGA
90Pb/10Sn

CF1144CGA
90Pb/10Sn

CG624
CGA
80Pb/20Sn

CG1152CGA
80Pb/20Sn

Copper ribbon
Column/ballheightColumn/balldiameter
CoplanarityNo
2.20mmNo
2.20mm0.52mm0.52mm－－Base material of
the package
Body size
No. of pins
Pitch
Base material
thickness
JEDEC
Registration

Ceramics

Ceramics

Yes
2.21 mm(0.087")0.51mm
(0.020")0.15mm
(0.006")
Ceramics

Yes
2.21 mm(0.087")0.51mm
(0.020")0.15mm
(0.006")
Ceramics

35.0mm square1140
1.00mm
1.5mm

35.0mm square1144
1.00mm
1.5mm

32.5mm square624
1.27 mm2.25 mm

JEDEC
MS-034-AAR-1

JEDEC
MS-034-AAR-1

JEDEC
MO-158 VAR
BE-1

Flip chip

Wire bonding

0.75mm

0.70mm

0.70mm

0.70mm－－－－Ceramics

Ceramics

Ceramics

Ceramics

35mm square
1152
1 mm
2.77 mm

27.0mm429
1.27mm
1.11mm26.0mm square572
1.00mm
2.85mm21.0mm square357
1.00mm
2.85mm

15.0mm square165
1.00mm
2.35mmJEDEC
MO-158 VAR
CG-1

JEDEC
MO-156－－－

Wire bonding

Wire bonding

Wire bonding

Wire bonding

Wire bonding― 2 ―JERG-0-054B(E)Primary mount Flip chip
structureTEXAS
NIPPON AVIONICS
INSTRUMENTS
S-CBGA-N429
SABG572-100
SABG357-100
SABG165-100
BGA
BGA
BGA
BGA
46Sn/46Pb/8Bi
Sn10/Pb90
Sn10/Pb90
Sn10/Pb90(center 8X8(center 5X5(center 3X3
ball)
ball)
ball)
Sn63/Pb37
Sn63/Pb37
Sn63/Pb37(periphery ball) (periphery ball) (periphery ball)
No
No
No
No
0.6mm
0.50mm
0.50mm
0.50mmJERG-0-054B(E)

1.3 Tailoring(1) The Japan Aerospace Exploration Agency (hereinafter referred to as “JAXA”) may
tailor the requirements in this standard for each contract in accordance with the purpose,functions, importance, scale, costs, etc. of target articles.
(2) The supplier in the contract may make proposals for appropriate tailoring in theprocess of consultations related to the contract. When tailoring, an examination shall be
performed of the elements related to the purpose, etc. of target articles shown in the above
paragraph (1).
2. RELATED DOCUMENTS
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.
Note that in the case that there is any discrepancy between this standard and the applicable
documents, this standard shall be given priority.
(1) JAXA standards (in Japanese)a. JERG-0-039

Standard for Soldering Process for Space Useb. JERG-0-040

Standard for Electronic Bonding Process for Space Usec. JERG-0-042

Standard for Printed Wiring Boards and Assemblies for Space Used. JERG-0-043

Standard for Surface Mount Soldering Process for Space Use(2) Public standards
JIS standards
JIS Z 3282 Soft Solders—Chemical Compositions and Forms
JIS Z 3284 Solder Paste
IPC standards
J-STD-005

Requirements for Soldering Pastes

J-STD-006

Requirements for Electronic Grade Solder Alloys and Fluxed andNon-Fluxed Solid Solders for Electronic Soldering Applications

ESA standards
ECSS-Q-ST-70-38C

Space product assurance High-reliability soldering for surface
mounting and mixed technology

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JERG-0-054B(E)

ECSS-Q-ST-70-61C High reliability assembly for surface mount and through holeconnections
Papers and other materials
ESA STM-266

Assessment of the Reliability of Solder Joints to Ball and Column
Grid Array Packages for Space Applications

2.2 Reference documents
The following documents provide information supplementary to the contents of this standard.
JEITA standards
JEITA ET-7407A

Environmental and Endurance Test Methods for CSP/BGA Package
on Mounting Condition

JEITA ED-7306

Measurement Methods of Package Warpage at Elevated Temperatureand the Maximum Permissible Warpage

MIL standards
MIL-STD-202

Test Method Standard, Electronic and Electrical Component Parts

MIL-P-28809A

Printed Wiring Assemblies

MIL-STD-883H

Method 2009.10, EXTERNAL VISUAL, paragraph 3.3.6

NASA standard
GSFC-STD-6001

Ceramic Column Grid Array Design and Manufacturing Rules for
Flight Hardware

IPC standards
IPC-7095B

Design and Assembly Process Implementation for BGAs

IPC-7351B

Generic Requirements for Surface Mount Design and Land PatternStandard

IPC-7711/21B

Rework, Modification and Repair of Electronic Assemblies

IPC LF-005

BGA Inspection & Lead-Free Defect Guide

IPC-9701A

Performance Test Methods and Qualification Requirements for Surface
Mount Solder Attachments

JEDEC standards
MO-156C

Square Ceramic Ball Grid Array Family 1.00, 1.27, and 1.50 mm Pitch

MO-158D

Ceramic Column Grid Array Family - SquareMS-034D

Plastic Square Ball Grid Array Family

4

JERG-0-054B(E)

ESA standard
ECSS-Q-ST-70-28C Repair and modification of printed circuit board assemblies for spaceUse
IEC standards
IEC 60191-6-4 1.0

Mechanical standardization of semiconductor devices - Part 6-4:
General rules for the preparation of outline drawings of surface
mounted semiconductor device packages - Measuring methods for
package dimensions of ball grid array (BGA)

IEC 60191-6-19 1.0 Mechanical standardization of semiconductor devices - Part 6-19:
Measurement methods of the package warpage at elevatedtemperature and the maximum permissible warpage
IEC 61188-5-8 1.0

Printed boards and printed board assemblies - Design and use - Part
5-8: Attachment (land/joint) considerations - Area array components(BGA, FBGA, CGA, LGA)

IEC 61191-6 1.0

Printed board assemblies - Part 6: Evaluation criteria for voids insoldered joints of BGA and LGA and measurement method

IEC 62137-1-4 1.0

Surface mounting technology - Environmental and endurance test
methods for surface mount solder joint - Part 1-4: Cyclic bending test

IEC 62137-1-5 1.0

Surface mounting technology - Environmental and endurance test
methods for surface mount solder joint - Part 1-5: Mechanical shear
fatigue test

JAXA documents
JERG-0-054-TM001 Collection of Technical Data of Standard for BGA/CGA Mounting
Process for Space Use (JERG-0-054)
JERG-0-054-HB001 Handbook of Standard for BGA/CGA Mounting Process for Space Use(JERG-0-054)
Research Papers, etc.
ESA STM-261

An Investigation into Ball Grid Array Inspection Techniques

ESA STM-265

Evaluation of Thermally Conductive Adhesives as Staking Compounds

duringthe Assembly of Spacecraft Electronics
Converting Ball Grid Array Components to Column Grid Array (SM-4028 Rev B SIXSIGMA)
Ceramic Column Grid Array (Actel Application Note AC190)
CBGA Surface Mount Assembly and Rework User’s Guide (IBM)5

JERG-0-054B(E)

Ceramic Column Grid Array Assembly and Rework User’s Guide (IBM)
Thermal Cycling Test Report for Ceramic Column Grid Array Packages--CCGA (ACTEL)JEDEC PUBLICATION JEP150 Stress-Test-Driven Qualification of and Failure
Mechanisms Associated with Assembled Solid State Surface Mount Components
JPL Microelectronics Reliability Volume 43, Issue 5 Qualification approaches and thermal
cycle test results for CSP/BGA/FCBGA
Virtex-4 QV FPGA Ceramic Packaging and Pinout Specifications (UG496 (v1.0) Xilinx)
IPC ELEC-SOLDER - Modern Solder Technology for Competitive Electronics
Manufacturing
3. TERMS AND DEFINITIONSThe Terms and Definitions used in this standard are based on paragraph 3 (Terms anddefinitions) of JERG-0-043. In addition, reference shall be made to Appendix I of thisstandard.

6

JERG-0-054B(E)

4. GENERL REQUIREMENTS
4.1 General
General requirement shall conform to paragraph 4.1 (General) of JERG-0-043.
4.2 Training and certification
Training and certification shall conform to paragraph 4.2 (Training and certification) of
JERG-0-043.
4.3 Design requirements(1) The design requirements related to PWBs shall be as per paragraph 6.1 of this standard.
(2) The temperature requirements for solder joint(s) during storage and operation shallconform to paragraph 4.3(1) (Design requirements) of JERG-0-043.
(3) Application of solder and flux shall conform to paragraph 5.3.1 (Solder and flux) of
JERG-0-043. As a rule, solder pastes conforming to J-STD-005 or JIS Z 3284 shall be usedin soldering. When resin 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 usedin lieu of Sn63/Pb37 or Sn60/Pb40 solder.
(4) The metals to be joined shall conform to paragraph 4.3(3) (Design requirements) of
JERG-0-043.
(5) The solder joint parts shall be as per Table 1-1 in this standard.
(6) The application of parts staking, conformal coating, etc. shall be as per JERG-0-040 andin addition paragraph 6.1.3, 6.2.4 and 6.2.5 of this standard.
(7) Inspection of the soldered joints shall be as per JERG-0-043 and in addition paragraph
6.3 and 7.3 of this standard.
4.4 Process certification tests
When certifying the process, a certification plan shall be submitted to JAXA and approval forthe plan shall be received in advance.
The general matters are stated below. The details shall be as per paragraph 6.4 of thisstandard.
4.4.1 Vibration/shock tests
The vibration/shock test shall be conditioned taking into consideration the applicable
environmental conditions, etc., and shall be reconditioned as necessary in cooperation with
JAXA.

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JERG-0-054B(E)

4.4.2 Thermal shock tests
In the case that the temperature of the solder joint(s) cannot satisfy the temperature range
between -30°C and +100°C during warehousing, storage and operation, paragraph 4.4.2 (1) of
this standard shall be applied.

In the case that the temperature range is satisfied,paragraph 4.4.2 (2) of this standard shall be applied.
(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, however when longer duration of exposure is
expected due to the pattern, the time of exposure shall be adjusted accordingly.
(2) Thermal shock test (II)Thermal shock test (II) shall conform to paragraph 4.4.2(1) (Process certification test (II)) of
JERG-0-039, or to 4.4.2(2) (Test method and conditions) of JERG-0-043.
4.4.3 Electrochemical migration test
Electrochemical migration test shall conform to paragraph 6.4.3 of this standard.
4.5 Manufacturing conditions
4.5.1 General(1) Paragraph 4.5(1) and (3) to (5) (Manufacturing conditions) of JERG-0-043 shall beapplied in this section.
(2) For soldering rework shall be applied paragraph 8 of this standard.
4.5.2 Manufacturing environment
Manufacturing environment shall conform to paragraph 4.5.1 (Manufacturing environment)of JERG-0-043.
4.5.3 In-process storage and handling
In-process storage and handling shall conform to paragraph 4.5.2 (In-process storage andhandling) of JERG-0-043.

8

JERG-0-054B(E)

4.5.4 Electrostatic discharge control
Electrostatic discharge control shall conform to paragraph 4.5.3 (Electrostatic discharge
control) of JERG-0-043.
4.6 Quality assurance
Quality assurance shall conform to paragraph 4.6 (Quality assurance) of JERG-0-043.

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JERG-0-054B(E)

5. APPROACH TO QUALITY ASSURANCE IN BGA/CGA MOUNTING
5.1 Definition of process assurance
Conventionally, visual inspections to directly confirm the workmanship of the soldering havebeen one of the important measures in quality assurance for solder joints in spacecraft.
However, BGA/CGA packages are different from general parts because they have a shapewith bottom only terminations, so visual inspections are not possible to be performed for all of
the solder joints.
For this reason, to guarantee the quality of the solder joint that cannot be visually inspected,
it is necessary to introduce the new approach of process assurance that builds quality inside
the processes. Process assurance refers to activities guaranteeing that quality is being
ensured by stipulating the people, materials, manufacturing equipment (machinery), work
methods (procedures, conditions) necessary to ensure that if the process is carried out inaccordance with the predetermined procedures and methods then the results of the process
will be in accordance with the purpose of the process, and then implementing the processaccordingly. Process assurance in BGA/CGA mounting indirectly guarantees that the qualityof the BGA/CGA solder joint is being ensured, instead of using a direct visual inspection, by
obtaining evidence that the three processes of (i) design and process verification, (ii)manufacturing process confirmation, and (iii) product inspections are being implemented
appropriately.
5.1.1 Design and process verification
In design and process verification, obtain evidence to prove that the design andmanufacturing process that applies the BGA/CGA mounting is valid. Firstly, use anengineering sample equivalent to the product to carry out a demonstration andcomprehensive evaluation and verification in order to realize the process. It is not necessary
for the engineering sample used here to be identical to the product; it is sufficient if it can beused to implement a confirmation of the workmanship of the solder joints and an evaluationand verification of reliability.
However, the selected members (parts and materials including the BGA and CGA package
and PWB*1, solder materials, staking materials, coating materials, etc.) and the properties ofthe engineering sample (thermal properties such as the coefficient of linear expansion,
thermal capacity, etc., and mechanical properties), structure (parts arrangement, mass, etc.)
must be nearly identical as the target product. Furthermore, the soldering process conditions
such as the amount of solder, the temperature profile, etc. and the manufacturing equipmentused shall be identical to the conditions and manufacturing equipment for processing the10

JERG-0-054B(E)product. In the case that the shape or structure of the product differs greatly from theengineering sample or in the case that different manufacturing equipment is used,
reimplement the design and process verification.
In the comprehensive evaluation and verification, carry out not only nondestructive
inspections including observations of the exterior appearance, etc. but also employ
destructive inspections to confirm the condition of the workmanship in detail, including thecondition of the voids and the solder joints on the back surface of the BGA/CGA, where cannot
be verified nondestructively. Moreover, implement a reliability evaluation test to investigate
the thermal and mechanical durability, and utilize that data to confirm the validity of thedesign and process.
If it cannot be proven that the new products are equivalent to the products for which
evaluations had been performed in the past, the product or an equivalent engineering sample
shall conduct reperformance of the demonstration experiment, to confirm that theworkmanship is equivalent to the evaluations that have been implemented in the past.
However, the reliability evaluation test may be omitted in the case that only the
manufacturing equipment is different and the case that there are grounds for inferring thethermal and mechanical durability from engineering samples for which reliability evaluation
tests have already been implemented.
Note *1: A test board in which a test pattern, etc. has been formed is acceptable for the PWB
used as an engineering sample but the specifications that have an effect on the soldering
process such as the pad shape of the solder joints, the thermal capacity including the layer
structure, board thickness, etc., and the fixing structure, etc. , shall be equivalent to thoseof the products.
5.1.2 Manufacturing process confirmation
In the manufacturing process confirmation, it shall be able to prove that the process used to
manufacture the product is the same as the process that was verified as valid in the design
and process verification.
Firstly, register the manufacturing equipment and the scope of the various process conditions
and standards actually applied in the design and process verification described in paragraph5.1.1 in the system of the quality assurance program possessed by the implementer, andcross-check against the implementation record for the product manufacturing in order toprove that those conditions are the same. For the quality record of the product manufacturing,
information shall be included that the product specifications and the manufacturing

11

JERG-0-054B(E)equipment and various process conditions applied in the design and process verification are
the same. Moreover, for conditions include elements that change with each implementation,
it shall be able to implement inspections or measurements prior to manufacturing the
product to provide the conditions that have not deviated from the scope of the registered
standards. For example, for the amount of solder inspect the solder paste printing height andprinting area of the product itself in order to prove the amount of solder is equivalent to theregistered data. Furthermore, for the heating profile when soldering, create a record showingthat the product was made with an equivalent heating profile by putting into a furnace andmeasuring a dummy board right before putting the product into the furnace.
5.1.3 Product inspections
A visual inspection of the product’s exterior appearance and nondestructive inspections suchas X-ray observations, etc. are implemented to determine the quality condition of the
products. In product inspections of BGA/CGAs for which destructive inspections cannot be
performed, evidence which shows the quality condition is limited to partial information, andonly information unique to the individual products (solder wetting, amount of foreignmaterials remaining in the periphery, metal foreign materials between the electrodes,
installation position alignment, and electrode absence) is verified. For example, in the visualinspection observe only the condition of the direct-view surface of the periphery of the solder
joint to confirm the condition of the solder wetting and the amount of foreign materials
remaining in the periphery. The condition of the back of the electrode and the central part ofthe package cannot be observed so confirm evidence that shows the soldering process inparagraph 5.1.2 is appropriate, in order to infer the overall condition, and deem that theplaces that cannot be observed visually are equivalent. Carry out observations usingtransmission type X-rays for nondestructive inspections of the places that cannot be observed
visually. However, inspections using X-rays entail the risk of exposure damage (degradation),including the surrounding parts, so sufficient examinations shall be performed before
establishing the inspection conditions.

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JERG-0-054B(E)

6. EXAMINATION ITEMS AND INSPECTION METHODS FOR THE ESTABLISHMENT
OF A BGA/CGA MOUNTING PROCESS
6.1 Examination items in board and mount structural design
6.1.1 Points to consider when selecting the PWB
Compared to SOP and QFP packages, BGA/CGA packages have poor stress relief properties,
so it is difficult to relieve stress caused by the difference in thermal expansion between the
package and the PWB. Therefore, regarding the new combination of the PWB and theinstalled BGA/CGA, sufficient caution shall be taken for the design and adequate reliability
evaluations of the prototypes shall be implemented (refer to Table 6-1).
Furthermore, the warping and flatness of the PWB influence the quality of the mounting
finish and have an effect on solder joint reliability. Therefore, the PWB shall be designed
taking into consideration mountability and reliability.
In the baking and reflow heating of the PWB, confirm in advance that warping of the PWB
before and after heating is at a level that will not become a problem.
Table 6-1 Materials used in the PWB and examples of their characteristic values
Materials

No.
(1)
(2)
(3)

Tg (°C)

polyimide)

Poisson's ratio

CTE (ppm/°C)-

1290000.35

17200 ~213

25000

0.15

12 ~ 15 (X)
12 ~ 16 (Y)50 ~ 80 (Z)-1400000.259 (Inver)

3.6 ~ 5.6 (X, Y)

Conductor (Copper foil)
Base material (modified

Modulus ofelasticity (MPa)CIC (Copper Inver Copper)

Ceramic (alumina): 6.7ppm/°C

BGA/CGA

(1)

PWB

(2)

(3)

Eutectic solder (Sn37Pb): 26.6ppm/°C
High-temperature solder (Sn95Pb): 29.2ppm/°C

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JERG-0-054B(E)

6.1.2 PWB design(1) Wiring design
The wiring design of the PWB shall be in accordance with JERG-0-042 however in the casethat the wiring design requirements prescribed in JERG-0-042 are not satisfied anywhere,
make those places clear. Furthermore, regarding the areas in which the requirements are
not satisfied, make sure through design verifications, evaluations, etc. that a sufficient
allowance has been made for withstand voltage, the electrical field, etc. in the wiring designusing an appropriate method.
(2) Pad design
As shown in Figure 6-1, there are two types of pad design: Dog-Bone and Via in Pad/Pad on
Via. One of these types shall be applied.
In the case of arranging vias, etc. which indents will occur inside the pad, sufficientconsideration shall be given to the amount of voids remaining.
Regarding the pad size, it is necessary to use the size (as the joint including the amount ofsolder) capable of relieving the stress of the difference in thermal expansion between the
package and the PWB in a well-balanced manner with the upper and lower joints of thecolumns and solder balls.
In the case of the Dog-Bone pad design, an adjacent through-hole that goes through to thelower layer is required, and normally the pad is not covered by the solder resist. Therefore,
when steadily implementing solder flow prevention or implementing underfill packing, it isdesirable to fill the through-hole with resin to block up the hole, and then cover all areas
other than the pad aperture with the solder resist.

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JERG-0-054B(E)

Pad diameter
Solder mask aperture
Hole diameter

Pad pitch(Upper surface)

Land diameter
Annular ring

(Cross-section)

Dog Bone(Upper surface)Resinembedding(Cross-section)

Via in Pad/Pad on Via

Figure 6- 1 Pad design image(3) Solder resist design
There are two types of solder resist design applied to pads as shown in Figure 6-2: NSMD
(Non-solder mask defined pad) and SMD (Solder mask defined pad).

(Upper surface)

Solder mask

Solder mask aperture

Solder mask

Pad

Solder mask aperture(Cross-section)

Figure 6- 2 Solder resist designs applied to the pads

15

Pad

JERG-0-054B(E)(4) Other matters to consider
When using surface treatment other than a solder coat, an evaluation of joint reliability
shall be implemented.
When employing specifications not in the JAXA qualified specifications in the PWB design,
it is necessary to implement a design verification and evaluation in advance.
The PWB shall be designed so that it conforms to all of the parts. A clearance around the
BGA/CGA to allow proper insertion of repair and rework instruments and tools shall beensured.
In particular in the case that rework is anticipated, the board design shall take rework into
consideration.
6.1.3 Structural design
When mounting the BGA/CGA, implement structural analyses to adequately examine thefixed pitch, number of fixing points, and board thickness, etc. of the PWB and the chassis, thereliability of the structural design shall be ensured. It is acceptable to implement underfill
and corner staking for the purpose of improving vibration resistance and shock resistancewhen necessary. (Refer to Figure 6-3)

Notes ○ : corner staking

Upper : corner staking
Lower: Under fill (left)

Figure 6- 3 Examples of fixing using corner staking

16

JERG-0-054B(E)6.1.4 Points to consider regarding mounting design
The CGA columns covered by this standard are comprised of solder (Sn10-Pb90 or
Sn20-Pb80) and copper ribbon. The joint of the CGA package and column is Sn63-Pb37
eutectic solder. Furthermore, the columns winding copper ribbon on the outside of the solder
core are connected so that the core and copper ribbon are coated with Sn63-Pb37 solder.
BGA is also connected not only with Sn63-Pb37 eutectic solder, but also with a combination ofsolders with different compositions.
Since the BGA/CGA mounting has this structure, adequate caution shall be taken in themounting design regarding the combination with the solder and the reliability of the joint.
6.2 Examination items in mounting
This section shows the examination items necessary for the establishment of the BGA/CGA
mounting process.
However, the examination items shown in this section are the standard items implemented toestablish the mounting process, and they can be replaced in the case that equivalent
mounting quality/reliability can be established using the own process design and process
management of each manufacturer.
6.2.1 Mounting materials
For the materials used in mounting, basically the materials prescribed in JERG-0-039 or
JERG-0-043 shall be used. The handling/use methods for the materials shall satisfy therequirements in the specifications prescribed by each manufacturer.
6.2.2 Soldering mounting
When examining the soldering mounting, specifications regarding the following items shallbe established.
(1) Baking of the members(1-1) Baking of the BGA/CGA
BGA/CGAs for which there are baking requirements shall be baked before the reflow
soldering, under the baking conditions recommended by the parts manufacturer. (This does
not apply in the case that the reflow soldering is completed after unsealing within the timeprescribed by the parts manufacturer.)
In some cases there is a concern of oxidation of the balls or columns due to the baking, so
prior to baking the members, the specifications such that the baking equipment, the17

JERG-0-054B(E)atmosphere in the baking furnace, the baking method, the baking temperature, the baking
time, and the storage method from after the baking to the mounting shall be established.
The major items and points to be cautious about are shown next.
(a) Oxidation inhibition• A baking method inside an inert gas shall be used.
• In the case that baking inside an inert gas is difficult, the method of removing, etc. theoxidized film of the soldering joint is also allowed but the reliability of the solder
connections shall be verified.
(b) Method
A baking method that will not damage the balls and columns during the baking shall be
used.
(c) Storage
A storage method that will inhibit the oxidation and absorption of moisture of thecolumns and balls after the baking shall be used. The time from after the baking to thereflow soldering shall be controlled.
(1-2) Baking of the PWB
It is necessary to bake the PWB prior to mounting the parts. In the case that the flatness of
the PWB becomes worse due to the baking, there is a possibility that it will affect the joint
reliability of the BGA/CGA. Therefore, in the case that there is a risk that the warping of
the PWB due to the heat of the baking might have an effect on joint reliability, use amethod that reduces warping as necessary. Prior to baking the PWB, the specifications of
the baking temperature, the baking time, and the method of storage until the mounting
onto the PWB shall be established. The duration from after the baking to the reflow
soldering shall be controlled.
(2) Solder paste printing
When establishing the printing process for the solder paste, the specifications such that thesolder paste printing equipment, the solder paste materials, the time from the solder paste
mixing to the printing, the volume after the solder paste printing, the appearance
accept/reject criteria after the solder paste printing, and the time from solder paste printing
until parts installation shall be established. The major items and points to be cautious
about are listed next.

18

JERG-0-054B(E)(a) Time
The time from the solder paste mixing until the commencement of the printing taking
into consideration the adhesiveness and moisture absorption properties of the solder
paste shall be controlled. Furthermore, the time from the end of the printing work until
the commencement of the reflow soldering shall be established.
(b) Finish• A method with no shortage and uniform thickness shall be used.
• The solder paste finish (shape, volume, etc.) after printing shall be managed. (It is
desirable to manage it numerically using volume, solder height, etc.)• The allowable value for the maximum alignment amount of the printing with respect
to the pattern of the PWB shall be established.
(3) Parts installation
When establishing the parts installation process, the specifications such that installationequipment, the inspection method after the parts installation, the accept/reject criteria forthe parts installation position, and the standards for the exterior appearance of the parts
before the parts mounting shall be established.
(a) Handling
For the installation of the BGA/CGA on to the PWB, a method that does not cause
deformation of the balls and columns shall be used.
(b) Installation sequence
The sequence for installing the BGA/CGA mounted on the PWB and the electrical parts
other than the BGA/CGA on the PWB is not prescribed.
(4) Reflow soldering
Basically the reflow temperature profile should be in accordance with the temperature
profile recommended by the parts suppliers and manufacturers but the temperature profile
while ensuring adequate consistency with the reflow temperature profile of the othermounting parts and considering the temperature distribution of the PWB shall be
determined.
When establishing the process for reflow soldering, the specifications of the reflow
equipment, the atmosphere inside the reflow furnace, the reflow profile, the time from theprinting work end until the beginning of the reflow soldering, the acquisition frequency of
the reflow profile, the parts temperature at the time of the reflow soldering, the fixing
methods of the PWB to the conveyancing fixtures of the package, and the reflow

19

JERG-0-054B(E)configuration shall be established. The major items and points to be cautious about are
shown next.
When using local (individual) reflow equipment, the differences in management items fromreflow equipment shall be clarified.
(a) Temperature profile
A temperature profile that does not exceed the upper limit for temperature/time in thetemperature profile recommended by the parts suppliers and manufacturers shall beestablished.
(b) Temperature data acquisition
In the case that parts with a large thermal capacity are to be mounted in theneighborhood of the mount position of the BGA/CGA and in the case that there are noparts in the neighborhood, there is a possibility that the reflow temperature distributionof the BGA/CGA will change. Therefore, in the case that the parts are to be mounted on
the peripheries of the BGA/CGA, the temperature data after taking into consideration
their thermal capacity shall be acquired.
(c) Warping of the PWB
There is a possibility that warping of the PWB due to reflow soldering may have an effecton the joint reliability of the BGA/CGA. When doing the reflow soldering of the
BGA/CGA, a method that reduces the warping amount of the PWB as much as possible
shall be used.
(d) Changes to the base material of the PWB
There is a possibility that the temperature distribution of the BGA/CGA will change dueto the base material changing, even in PWBs that are the same size. In the case thateven a PWB for which reflow has been implemented has a different base material incomparison to the previous PWB, it shall be verified that there is no effect on thetemperature distribution of the BGA/CGA.
(e) Changes to the pad design
There is a possibility that even with the same size and base material, discrepancies inheat conductivity will occur due to the pad design changing, and therefore the melt
timing (melt time) of the solder will change. In the case that even a PWB for which
reflow has been implemented has a different pad design than the previous one, it shallbe verified that there is no effect on the fillet form, etc. of the BGA/CGA solder joint(s).
(f) Changing the parts
In the case that the size of the BGA/CGA has changed even for a board size/base material
for which reflow has been implemented, there is a possibility that the temperature

20

JERG-0-054B(E)distribution of the BGA/CGA will change. In the case that the size of the BGA/CGA isdifferent than the previous one, it shall be verified that there is no effect on thetemperature distribution of the BGA/CGA.
The same applies if the surrounding heat capacity of components other than the target
BGA/CGA or PWB size is changed.
6.2.3 Cleaning
When establishing the cleaning process for the BGA/CGA, the specifications related to thecleaning equipment, the cleaners (solvents), contamination management, the cleaning
temperature, the cleaning time, the cleaning method, the accept/reject criteria for theexterior appearance after cleaning, the method of inspecting the exterior appearance after
cleaning, the method of preventing the migration of foreign materials after cleaning, themethod of inspecting foreign materials on the back surface of the BGA/CGA, and thestandards for the size and amount of foreign materials on the BGA/CBA back surface shall be
determined. The major items and points to be cautious about are shown next.
(1) Flux residue
A cleaning method with which flux residue will not occur in the solder joint places of the
BGA/CGA shall be established. However, allow for flux residue by acquiring data providing
technical backing for the fact that migration does not occur as a result of implementing anelectrochemical migration test due to flux, and implementing underfill and conformal
coating.
(2) Foreign materials including solder balls, etc.
A cleaning method that can remove foreign materials such as solder balls shall beestablished.
(3) Cleaning method
For the cleaning, a method that will not damage the balls and columns shall be applied.
6.2.4 Staking and fixing(1) CGAThe CGA is a structure that supports the ceramic package with solder columns, and a load
is imposed on the columns due to vibrations and shocks. There is a possibility that an
excessive load will damage the joint reliability of the CGA, so in some cases measures suchas fixing the CGA in place, etc. are necessary. When establishing the fixing method, refer toparagraph 4 of JERG-0-040, and the selection of the materials, the coating method, the21

JERG-0-054B(E)curing conditions, and the standards and inspection method for the exterior appearance ofthe finish shall be considered. The major items and points to be cautious about are shown
next.
(a) Materials
The difference in coefficient of thermal expansion from the CGA and PWB shall beconsidered.
(b) Inspections• The structure shall enable confirmation of the condition of the fixing by the visualverification.
• In the case that the condition of the fixing cannot be verified by the visual verification,
the process of the fixing method shall be established• The staking materials shall not attach to the column.
(2) BGA
When applying the underfill, there is a risk that the BGA underfill will impose constraints
on the removal of the BGA, so adequate caution is necessary.
There are cases in which it has been evaluated that the underfill expedite thermal fatigue
in the solder joints due to the difference in the coefficient of thermal expansion between theunderfill materials and the ceramics in the thermal cycles, and therefore causes cracks(refer to ESA STM-266).
In the case that the underfill materials are to be used for the BGA, the following mattersshall be considered when selecting the underfill materials.
(a) Materials
The viscosity, the glass-transition temperature, the coefficient of thermal expansion, andthe adhesiveness with the board, etc. shall be considered.
(b) Method
A method capable of uniform fill shall be used.
(c) Inspection
In the case of underfill, the condition of the filling cannot be verified using visualverification, so the process of the filling method shall be established.
In the case of staking materials, the staking materials shall not attach to the balls.

22

JERG-0-054B(E)

6.2.5 Coating
As a general rule, conformal coating shall be implemented to take measures for corrosion
prevention and insulation for the PWB on which the parts are mounted and the electrodes ofthe parts. It is necessary to carry out conformal coating of the solder joint(s) of the CGA for asimilar purpose but if the coating materials are filled into the entire bottom surface of the
package there is a possibility of damaging the properties of the CGA (mitigation of thethermal strain using the expansion, contraction, etc. of the columns) so it is acceptable toapply the coating to the solder joint rather than the entire column.
However, in the case of coating only the solder joint, measures to ensure that foreignmaterials do not migrate to the bottom surface of the parts shall be taken. In the case thatthe coating materials are to be filled into the entire bottom surface of the package, carry out
an adequate evaluation and it shall be confirmed that the properties of the CGA have notbeen damaged by the coating. Regarding the BGA as well, in the case that a conformal
coating is to be applied, an adequate evaluation shall be conducted. When establishing theprocess for conformal coating, the specifications related to the selection of the coating
materials, the coating method, the curing conditions, and the standards and inspection
method for the exterior appearance of the finish shall be established by referring paragraph 4of JERG-0-040. The major items and points to be cautious about are shown next.
(a) From mounting to before coating
Measures to prevent the migration of foreign materials between the balls or columns shallbe carried out.
(b) Scope of the coating• There is a possibility that solder balls will occur at the time of the reflow soldering, andthose solder balls will exist on the board. Consequently, conformal coating shall be
implemented for at least the PWB and the solder joints between the balls/columns andthe PWB.
• The coating shall be uniform with no unevenness.
(c) Coating method
A manufacturing process for carrying out process assurance shall be established.

23

JERG-0-054B(E)

6.3 Inspections
6.3.1 Visual inspection
The scope that can be verified from the peripheral side surface shall be visually inspected inaccordance with JERG-0-043. The criteria shall be as shown in shown in Table 0-1.
The visual inspection is carried out using a stereomicroscope capable of magnification of 20
times or more (when necessary, a microscope with a prism mechanism) or a fiberscope
microscope, depending on the joint size.
Table 6-2 Visual inspection items and criteria for BGA/CGA (1)Requirements
Items
BGA
CGA
The column overhang
The ball offset from the
Pad-ball (column)
amount from the padpad shall be 25% or lessalignment
shall be 15% or less of theof the PWB pad diameter
PWB pad diameter－
Column tilt (CGA)
5° or less
Chips and deflections areBall (column) shape
Chips are nonexistentnonexistent
Ball (column) absences
Nonexistent
Solder bridge
Nonexistent
The solder paste has
The solder joint is
Soldered connection (2)melted and smoothly
smoothly connected fromconnected to the ballthe column to the pad
The solder is filled
between the bottom of
the column and the pad iswet, and forms a solder－
Solder fillet
fillet that moistens 180°or more of thecircumference of thecolumnMetal foreign materials of 0.1mm or more are
Foreign materials
nonexistent
Note (1) Inspect the scope that can be visually verified from the peripheral side of the
package (Figure 6-4).
Note (2) Appearance (surface condition) varies depending on the solder composition of theballs and columns.

24

JERG-0-054B(E)Xilinx-made
CGA(Vertex4
CF1144)After reflow

TI-madeCBGAMicrosemimade
CGA(CG1272)

After reflow

CBGA(Reference)

Figure 6- 4 Examples of observations of the exterior appearance

6.3.2 Nondestructive inspection
Regarding the back surface of the BGA/CGA which cannot be visually inspected, anappropriate nondestructive inspection such as X-ray inspection, etc. shall be carried out inaccordance with Table 0-2.
In the case that X-ray inspection equipment is to be used, the resolution of the X-ray
equipment shall be able to detect solder balls having a diameter of 0.03 mm at least.
Furthermore, in the case that foreign materials have migrated into the back surface of the
BGA/CGA after the mounting, inspection and removal may be difficult, so measures to reduce
the risk of foreign materials migration shall be examined.
As shown in Figure 0-2 and Figure 0-3, the void ratio is defined by area. As shown in the A-A’cross-section of Figure 0-3, in the case of the CGA the solder joint between the column and
PWB side pad shall be observed.
Furthermore, in the case that multiple voids exist in one joint, calculate the void ratio fromthe sum total of the void area as shown in Figure 0-4. Note that in the case that large
volumes of voids occur, by revising the process including the reflow heating conditions, etc.,
the number of voids shall be reduced.
Note that when performing non-destructive inspection using X-ray, the X-ray irradiation time
becomes an issue. So for X-ray inspection, it shall be ensured that there is no effect on
BGA/CGA by calculating radiation resistance in advance.

25

JERG-0-054B(E)

Table 6-3 X-Ray inspection items and criteria for BGA/CGA
Requirements
Items
BGA
CGA
The column overhang
The ball offset from the
Pad-ball (column)
amount from the padpad shall be 25% or lessalignment
shall be 15% or less of theof the PWB pad diameter
PWB pad diameter
Marked tilts are
Column tilt (CGA)
nonexistent (1)Ball (column) absences
Nonexistent
Solder bridge
Nonexistent
Soldered connection
Unmelted and unconnected places are nonexistent
The void ratio of the CGA
The void ratio of the BGA
column joint
Voids
ball joint cross-section
cross-section shall beshall be 25% or less (2)25% or less (2) (3)Impermeable foreign materials of 0.1mm or more are
Foreign materials
nonexistent (4)1
Notes ( ) Refer to Figure 16-23 in ECSS-Q-ST-70-38C.
(2) The void ratio is defined using the cross-sectional area (refer to Figure 0-2 andFigure 0-3).
(3) The place that is observed is the solder connection of the pad and column on the
PWB side.
(4) ECSS-Q-ST-70-38C contains the statement “The total number of solder balls having
a diameter greater than 0.03 mm shall not exceed 10 per device.” Carry out the processevaluation with that number as the target.

26

JERG-0-054B(E)

Package side padMax. void cross-section

Void

A

(X-ray transmission image)×

A’

Max. joint cross-section
PWB side pad(X-ray transmission image)[Front view][A-A’ cross-section view]2D π V 
(DV )22 
Void ratio OV = =
2(DS )2
 DS π 2 Figure 6- 5 Definition of the void ratio (BGA)

Package side padMax. void cross-section

Column(X-ray CT image)

Void

A

×

A’
Joint cross-section
PWB side pad(X-ray CT image)[Front view][A-A’ cross-section view]2D π V 
2(DV )2 Void ratio OV = =
2(DS )2
 DS π 2 Figure 6- 6 Definition of the void ratio (CGA)27

JERG-0-054B(E)

D2
D1

×

Void ratio OV =(D1 )2 + (D2 )2(DS )2

Figure 6- 7 Definition of the void ratio in the case that multiple voids exist (BGA/CGA)(calculate the void ratio from the sum total of the void area)

6.3.3 Destructive inspection
Carry out a destructive inspection of the engineering sample to confirm the initial conditionof the solder joint.
(1) It shall be ensured that there is no wetting on the solder joints between the package andthe ball/column, and between the ball/column and the PWB, and abnormalities in the joint
boundary are nonexistent.
(2) Inspection of the staking, underfill, and fixing
The following items shall be satisfied.
(a) In the case that staking materials are to be used, the staking materials shall not
attach to the columns and solder joints.
(b) In the case that underfill materials are to be used, it shall be possible to fill them inuniformity.
(c) There shall be no cracks or peeling in the staking.
(d) The ball part shall not be bonded.
(3) Inspection of the coating
In the case that coating is to be applied to the products, apply the coating to a wiring boardthat was manufactured using a PWB, BGA/CGA and process equivalent to those of the
product, and use a destructive inspection to confirm that the coating has been applied
uniformly.

28

JERG-0-054B(E)

6.4 Reliability evaluation
The following evaluation tests shall be implemented in order to prove the validity of thedesign, structure, manufacturing process, etc. to be applied.
However, the evaluation items, conditions and criteria may be stipulated separately based on
the product environment specifications.
Furthermore, in the case that the purpose is to evaluate validity with respect to partialchanges to designs, structures, manufacturing processes, etc. which have already been
evaluated, the evaluation items may be selected after taking into consideration theirinfluence with respect to the changed parts.
6.4.1 Evaluation sample
The evaluation sample shall be an engineering sample produced with members, structures,
manufacturing processes, etc. equivalent to those of the product, or a product extracted froman identical manufacturing lot.
For the engineering sample it is acceptable to use a TEG (Test Engineering Group)
specifically designed for individual evaluation purposes, but it shall be a TEG for which thethermal and mechanical properties can be evaluated as equivalent to the products or at thethreshold limit value.
As a general rule the test material amount of the evaluation sample shall be at least three
items per package type. However, this shall not apply in the case that the validity of theevaluation results can be judged appropriately.
(1) The BGA/CGA to be used shall be one which has equivalent electrical functions to the
product or is a mechanical sample (a dedicated evaluation package with daisy chain wiring,etc. for confirmation of conduction), however the shape, pitch, materials, and terminal
treatment of the terminal shall be equivalent to the products to be applied. Furthermore, inthe case that difference in size, the question of whether the vertical, horizontal, andthickness dimensions, the number and the arrangement of the terminals, the mass, andthermal capacity are appropriate based on the purpose of the evaluation shall be examined.
Moreover, in the case that a package possessing equivalent functions to the product is to be
used, and the threshold limit value is to be evaluated using this package, defectdetectability with respect to the disconnections or short circuits shall be taken into
consideration in advance.
(2) When deciding the PWB to be used, materials of the base material/solder resist/metalcore, etc. of the insert, pattern shape/the cross-section structure/the surface treatment of29

JERG-0-054B(E)the solder joint, the size/the layer structure/the board thickness of the board, and thediameter/position of the through-hole shall be taken into consideration based on theevaluation purpose.
(3) In the case that the purpose is to evaluate the mechanical structure with vibration tests
and shock tests, etc., the stiffness, fixing structure (in the case of fixing using bonding, thisincludes the properties of the bonding surface), and similarity of the PWB stiffness,
including the mass of the dummy parts, etc. shall be considered.
(4) In the case that an environmental test entailing temperature changes is to be
implemented, the insert materials arrangement in the PWB in the in-plane direction andthickness direction, and the positional relationships and spacing of the parts in the in-plane
direction and on the front and back shall be considered.
(5) The evaluation sample shall go through a manufacturing process, including processes,
management procedures and in-process inspections, etc. which are equivalent to those of
the product.
(6) In the case that rework is to be implemented through removal and replacement of arejectable package, care shall be taken to ensure that the rework is subject to evaluation in
the reliability test; for example by using a sample that has been through an equivalent
history.
6.4.2 Reliability verification program
Implement the tests in accordance with the flowchart shown in Figure 0-5 and if defect is
detected, the tested subject shall be rejected.
However, in the case that defect is identified in a visual inspection or a DPA, the verification
program can be acceptable if it can be verified using statistical methods, such as the Weibull
Analysis, etc. based on the specimen size that the property service life in the thermal shock
test (a cumulative defect ratio of 63.2%) is at least a cumulative 500 cycles or at least the
number of equivalent cycles in the temperature cycling test.

30

JERG-0-054B(E)Assembly of engineering
sample or products

Assembly of engineering
sample or products after
rework process

Min. 3PKG
Electrical test (initial

Thermal shock test (1st time)measurement) (6.4.2.1)(6.4.2.5)

Visual inspection (initial

Electrical test

inspection) (6.4.2.2)(6.4.2.1)

Visual inspection(6.4.2.2)

Vibration test (initialinspection (6.4.2.3)

Electrical test

Thermal shock test (2nd time)(6.4.2.1)(6.4.2.5)

Electrical

Visual inspection(6.4.2.2)

test

(end

point

measurement) (6.4.2.1)

Shock test

Visual inspection(6.4.2.4)(final inspection) (6.4.2.2)

Min.2PKG

Electrical test
(6.4.2.1)

DPA I and II(6.4.2.6 and 6.4.2.7)

Visual inspection(6.4.2.2)

Figure 6- 8 Reliability verification program flowchart

6.4.2.1 Electrical test
Electrical test shall be as per Table 0-3.
The types of evaluation sample used in the electrical tests, and the test content and criteria
shall be as per Table 0-3.

31

JERG-0-054B(E)

Table 6-4 Electrical tests
1

2

Evaluation sample

Test content (1)Parts and board withfunctions equivalent to
the productA TEG with daisy chain
wiringElectrical properties test
equivalent to the products (2)Criteria
As per the parts
specifications (2)Conduction resistance test

A fluctuation of 10% ormore with respect to theinitial measurement isrejectable (3)Notes (1) In the case of an end point measurement, in addition to the room temperature test
also implement tests at the highest temperature and lowest temperature of thetemperature range at which operation is guaranteed as prescribed in the productenvironment specifications (and as necessary add the temperature margin).
(2) The test and criteria shall be able to confirm the conduction of the all signal
terminal.
(3) In the case of conduction resistance measurements at the highest temperature andthe lowest temperature, make the determination excluding the fluctuation rangethat is expected based on the temperature coefficient of conductor resistance.
6.4.2.2 Visual inspection
The visual inspection shall be performed in accordance with paragraph 0 of this standard.
However, this is limited to the case in which inspection of the solder joints, etc. is feasible.
The visual inspection is carried out using a stereomicroscope capable of magnification of 20
times or more (when necessary a microscope with a prism mechanism) or a fiberscope
microscope, depending on the joint size, but the scope of the inspection shall be the visiblearea such as the outside of the outer peripheral balls / columns of the package, that can bepractically inspected.
The requirement for the column tilt (CGA) shown in paragraph 0 and Table 0-1 of thisstandard does not apply in the visual inspection (final inspection) shown in the flowchart in
Figure 0-5.
Regarding the determination of crack propagation, the package will be determined to be
rejectable in the case that propagation is seen in the solder joints between the package andthe ball/column and between the ball/column and the PWB of a cumulative 1/4 or more of theperimeter in the case that the entire circumference of the joint can be inspected, or acumulative 1/2 or more of the terminal width in the case that the joint can only be inspectedfrom one side.
However, sacrificial terminals, which are designed on the assumption that the crack would
propagate, are excluded from the scope of the inspection. Furthermore, except in the initialinspection, in the case of surface wrinkles and dullness in the gloss and deformation of theball and column for which a clear crack cannot be identified, and furthermore in the case thata metallic ribbon, etc. is embedded in the solder ball/column and the package is designed for32

JERG-0-054B(E)the purpose of ensuring electrical continuity even when a crack propagates in the solder partof the column, and within the scope that a ribbon exists, these cases can be excluded frombeing determined rejectable.
6.4.2.3 Vibration test
The vibration test shall be in accordance with the product environment specifications.
Note that in the case that the test is to be applied to multiple projects, the test conditions thatare severer for the fatigue life of the solder joints shall be applied. Consistency with themonitoring method of the vibration level and design concept in the evaluation test shall beensured.
Furthermore, during the test it is desirable to carry out continuously or intermittently atappropriate intervals electrical monitoring that can confirm the connectivity of the joints,
including the electrical operation, etc.
6.4.2.4 Shock test
The shock test shall be in accordance with the product environment specifications. Note thatin the case that the test is to be applied to multiple projects, the severer test conditions shallbe applied. Consistency with the monitoring method of the shock level and design concept in
the evaluation test shall be ensured.
6.4.2.5 Thermal shock test
Implement the thermal shock test in paragraph 4.4.2 (2) of JERG-0-043 (-30°C for at least 30
minutes/temperature change within 5 minutes/+100°C for at least 30 minutes) for 200 cycles
the 1st time and 300 cycles the 2nd time, or as an equivalent method implementation of thetemperature cycling test in paragraph 4.4.2 (1) of JERG-0-039 (-55°C for at least 15 minutes/
temperature change of about 30 to 90 minutes/+100°C for at least 15 minutes) for 80 cycles
the 1st time and 120 cycles the 2nd time.
Furthermore, during the test carry out continuously or intermittently at appropriate
intervals electrical monitoring that can confirm the connectivity of the joints, such as
electrical tests, etc.
It is also acceptable to omit the electrical tests and visual inspections implemented in the 1st
and 2nd thermal shock tests and implement a consecutive 500 cycles (200 cycles in thetemperature cycling test) instead.

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JERG-0-054B(E)

6.4.2.6 DPA I (Cross-section inspection)
Extract at least one sample for each package type from the specimen and implement thecross-section inspection of at least one place in accordance with paragraph 6.3.3.
The position of the cross-section inspection shall be the area for which the greatest amount ofdamage is predicted in the design or the area which is judged to have a lot of damage by thevisual inspection.
In the case that a crack is identified in a ball/column or the surrounding conductive materials,
the package shall be determined to be rejectable in the case that it exceeds a cumulative 25%of the width (or diameter) of the conductive part in the cross-section area.
However, sacrificial terminals, which are designed on the assumption that the crack would
propagate, are excluded from the scope of the inspection.
Furthermore, in the case that a metallic ribbon, etc. is embedded in the column and the
package is designed for the purpose of ensuring electrical continuity even when a crack
propagates in the solder part of the column, and within the scope that a ribbon exists, thiscase can be excluded from being determined rejectable as long as there is no damage to themetallic ribbon.
6.4.2.7 DPA II (Dye penetrant test)
Extract at least one sample for each package type from the specimen and implement the dyepenetrant test.*2
The position of the inspection of the penetration part shall be the area for which the greatest
amount of damage is predicted in the design or the area which is judged to have a lot ofdamage by the visual inspection.
In the case that in the dye penetrant test there are penetration traces exceeding 25% of theoriginal joint area, the entire terminal shall be determined to be rejectable.
However, sacrificial terminals, which are designed on the assumption that the crack would
propagate, are excluded from the scope of the inspection.
Furthermore, in the case that a metallic ribbon, etc. is embedded in the column and the
package is designed for the purpose of ensuring electrical continuity even when a crack
propagates in the solder part of the column, and within the scope that a ribbon exists, thiscase can be excluded from being determined rejectable as long as there is no damage to themetallic ribbon.
Note *2: Implementation of the dye penetrant test is difficult in the case that the conformal
coat cannot be peeled off or in the case that the underfill has been applied, etc. In these cases,

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JERG-0-054B(E)make the accept/reject determination by increasing the number of cross-section places anddirections of the DPAI (cross-section inspection) to make the evaluation. Furthermore, in thecase of CGA, it is acceptable to make the accept/reject determination using the DPAI
(cross-section inspection) instead of the dye penetrant test.
6.4.3 Electrochemical migration test (insulation reliability test)
In the case that flux residue is allowed on the back surface part of the BGA/CGA, thefollowing evaluation test shall be carried out to obtain the technical judgment that the flux
residue is harmless.
Furthermore, in the case that flux residue is allowed, a conformal coating shall be applied.
(1) Use an evaluation sample that simulates the worst case for the condition of the cleaning(a comb-shaped electrode board, etc.) to carry out the electrochemical migration test, it
shall be verified that insulation resistance degradation and migration does not occur underhigh temperature and humidity conditions.
(2) A base material, surface treatment, solder materials, flux materials, and coating
materials equivalent to those of the product shall be used in the evaluation sample.
(3) The test conditions shall be in accordance with the insulation reliability test in
paragraph 4.4.2 (4) (60°C, 90-95% RH, rating bias applied) of JERG-0-043.

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JERG-0-054B(E)
7. CONTROL ITEMS IN BGA/CGA PRODUCTS PRODUCTION
7.1 Parts management
7.1.1 Receiving inspection
In the receiving inspection, carry out the confirmation of designation, the number of items,
and the exterior appearance. However, in the case of the CGA the column is easily deflected,
meaning that caution is required for the handling, so the acceptance inspection may beomitted.
Furthermore, to ensure that the column is not deflected in the processes from receiving toboard mounting, such as repacking, transportation and storage, etc., identify the risks
arising from the handling of the CGA in each process and clarify the handling rules in orderto reduce the risks. In addition, after the receiving inspection, it is desirable not to unpack
the parts during the intermediary processes leading up to the mounting.
7.1.2 Storage
In the electrodes of the BGA/CGA the solder materials and the copper of the end surface ofthe ribbon are exposed. For these materials, a storage method that inhibits oxidation and theabsorption of moisture shall be used.

In particular, in the case of parts that require

management of the absorption of moisture, the parts as stipulated by the parts
manufacturers shall be managed. Furthermore, it is desirable to store the parts using thepacking configuration they were in when they were delivered from the parts manufacturers.
7.2 Control items in mounting and the standards for the items
When producing products based on the mounting processes established by each mountmanufacturer using the results of evaluation test for the purpose of establishing themounting process, the manufacturing equipment and conditions for those products shall be
reliably maintained and managed. Moreover, in the following items statements are madewith respect to the particularly important elements.
7.2.1 Soldering mounting(1) Baking of the members
For baking of the members, the following items in addition to the equipment, conditions,and methods established in paragraph 6.2.2 (1) of this standard shall be managed.
(a) Baking of the BGA/CGA
When baking the BGA/CGA, the baking temperature and the baking time shall be
managed and recorded. Furthermore, the storage method from after baking until themounting on the PWB shall be managed.

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JERG-0-054B(E)(b) Baking of the PWB (Dehumidification)
As a general rule, the baking of the PWB in accordance with paragraph 5.3.1 (Parts andmaterials inspection) of JERG-0-039 shall be implemented. The baking temperature andthe baking time shall be managed and recorded. The storage method until the mounting
on the PWB shall be managed.
(2) Solder paste printing
When doing the solder paste printing, manage the following items in addition to theequipment, materials, and methods established in paragraph 6.2.2 (2) of this standard.
(a) The time from the solder paste mixing to the commencement of printing shall be
managed and recorded.
(b) The time from the printing to the installation of the parts(c) Regarding the printing height, shape or volume, etc. carry out a total inspection, it
shall be confirmed that they are within the standards prescribed based on theestablishment of the process. The results shall be recorded.
(d) Regarding the printing position, carry out a total inspection, it shall be confirmedthat they are within the standards regarding maximum alignment amount prescribedbased on the establishment of the process. The results shall be recorded.
(3) Parts installation
When installing the BGA/CGA, the following items in addition to the equipment andmethods established in paragraph 6.2.2 (3) of this standard shall be managed.
(a) Visual standards for the parts before the mounting of the parts(4) Reflow soldering
When doing the reflow soldering of the BGA/CGA, the following items in addition to theequipment, conditions, and methods established in paragraph 6.2.2 (4) of this standard
shall be managed. A discrepancy between the test configuration in the establishment of theprocess (the BGA/CGA, the PWB, and the heat load dummy) and the actual configuration
used for the reflow soldering (the BGA/CGA, the PWB, and the other electrical parts) is
only allowed in the case that evidence is possessed proving that the temperature
distribution of the BGA/CGA mounting area is equivalent.
(a) Confirmation of the reproducibility of the temperature profile
Prior to the reflow soldering, it shall be confirmed that the manufacturing equipment
can reproduce a temperature profile equivalent to the reflow implemented in the37

JERG-0-054B(E)establishment of the mounting process. When acquiring the temperature profile, thefollowing items shall be managed. The results shall be recorded.
• Temperature measurement position• Temperature and time of the acquired temperature profile data
• Confirmation frequency(b) Reflow soldering
When doing the reflow soldering, the following items shall be managed.
• The time from the end of the printing work to the commencement of the reflow• The reflow configuration (whether or not there are parts installed other than the
BGA/CGA, the PWB transfer direction, the PWB transfer speed, etc.)
7.2.2 Cleaning
When cleaning a PWB with a BGA/CGA installed, the following items in addition to theequipment, materials, and methods established in paragraph 6.2.3 of this standard shall be
managed.
• The method for preventing the migration of foreign materials to the bottom surface of
the BGA/CGA
7.2.3 Staking and fixing
When staking and fixing a BGA/CGA installed in a PWB, the following items in addition to
the materials, equipment, conditions, and methods established in paragraph 6.2.4 of thisstandard shall be managed.
• A method in which the staking materials do not attach to the columns
7.2.4 Coating
When applying the coating, the process using the materials, equipment, conditions, andmethods established in paragraph 6.2.5 of this standard shall be managed.

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JERG-0-054B(E)
7.3 Product inspections
7.3.1 Visual inspection
The inspection items are the same as in paragraph 0. The scope that can be verified from theperipheral side surface shall be visually inspected in accordance with Table 7-1.
The inspection results shall be recorded.
Table 7-1 Visual inspection items and criteria for BGA/CGA (1)Requirements
Items
BGA
CGA
Pad-ball (column)alignment

The ball offset from thepad shall be 25% or lessof the PWB pad diameter

The column overhang
from the pad shall be
15% or less of the PWB
pad diameter
Column tilt (CGA)
Marked tilts are－nonexistent (2)Ball (column) shape
Chips are nonexistent
Chips and deflections arenonexistent
Solder bridge
Nonexistent
Soldered connection
The solder paste has
The solder joint ismelted and smoothly
smoothly connected fromconnected to the ballthe column to the pad
Solder fillet
The solder is filled
between the bottom of
the column and the pad
is wet, and forms a solder－
fillet that moistens 180°or more of thecircumference of thecolumnForeign materials
Metal foreign materials of 0.1mm or more arenonexistentNotes (1) Inspect the scope that can be visually verified from the peripheral side of the
package.
(2) Refer to Figure 16-23 in ECSS-Q-ST-70-38C.
7.3.2 X-ray inspection
Regarding the back surface of the BGA/CGA which cannot be visually inspected, as a generalrule carry out the inspection using transmission type X-rays in accordance with Table 7-2.
If items shown in the table other than the X-ray inspection equipment can be detected,
inspections using substitute equipment are allowed. The X-ray inspection equipment to be
used shall have the resolution stated in paragraph 6.3.2. Furthermore, in the case that
foreign materials have migrated into the back surface of the BGA/CGA after the mounting,inspection and removal may be difficult, so examine measures in advance to reduce the riskof foreign materials migration. The inspection results shall be recorded.

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JERG-0-054B(E)
Table 7-2 X-Ray inspection items and criteria for BGA/CGA
Requirements
Items
BGA
CGA
Ball (column) absences
Solder bridge
Foreign materials

Column tilt (CGA)

Nonexistent
NonexistentImpermeable foreign materials of 0.1mm or more arenonexistent.
Impermeable foreign materials less than 0.1mm shallbe a size of 1/2 or less of the gap between the pads
No significant collapse

7.4 Storage and transportation
The method for preventing the migration of foreign materials to the bottom surface of the
BGA/CGA shall be managed.
8. REWORK
Rework for the purpose of re-use of the BGA/CGA is prohibited. In this section the rules
regarding the re-use of boards, etc. with the BGA/CGA removed are prescribed.
In the case that rework is to be implemented, on the assumption that the design
considerations (paragraph 6.1.2 (4) of this standard) have been satisfied, processes such as
the removal method and re-mounting method, etc. shall be established in advance and thereliability evaluation shall be implemented in accordance with paragraph 6.4.2 of thisstandard.
The re-heating method at the time of the rework is limited to local reflow.
When reworking, the following items; heating equipment, identification (ID) of the dedicatedfixtures (if required), the heating method, the management standards related to theincreased temperature and exposure time of the PWB, the management standards related tothe increased temperature and exposure time of the peripheral parts, the management
standards related to the number of reworks, and the state of damage to the pads and resists
after removal shall be managed.

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JERG-0-054B(E)Appendix I Terms and definitions(1) Back surface
This refers to the surface on the package side on which the electrode of the BGA/CGA isinstalled.
(2) Ball fall-out
This refers to the solder ball in the BGA package falling out so that it is not in the prescribed
position.
(3) BGA (Ball Grid Array)
A BGA is a surface mounting LSI package that forms bumps in a grid pattern on the bottom
surface of the package as the external connection terminal.
(4) Bottom surface
This refers to the space from the back surface of parts to the top surface of the PWB.
(5) CGA (Column Grid Array)
A CGA is a surface mounting LSI package that forms columns in a grid pattern on the bottom
surface of the package as the external connection terminal.
(The CGA can achieve the effect of mitigating the thermal stress between the board andpackage by replacing the ball-shaped bumps of the BGA with metals, alloys or theircompounds to form a cylindrical external connection terminal.)(6) Column
The columns are cylindrical electrodes lined up in a grid pattern of the CGA.
(7) Column fall-out
This refers to the solder column in the CGA package falling out so that it is not in theprescribed position.
(8) Column tilt
This refers to the angle of tilt of the column with respect to the vertical direction of the CGA
package.

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JERG-0-054B(E)(9) Coplanarity
This shows the coplanarity of the tips of the bumps or columns, and refers to the homogeneityof the external terminal tips (lowest surfaces) with respect to the PWB mounting surface of
the BGA and CGA.
(10) Dog-Bone
This is the connection pad on the PWB that is opposite to the external connection terminal of
the BGA and CGA, and is the connection structure of the PWB pattern that forms the land of
the through-hole for the inner layer connection adjacent to the soldering pad.
It is called by this name because it looks similar to the toy for dogs which is a bone in the
shape of a barbell.
(11) NMSD (non-solder mask defined) pad
This is a pad structure that defines the pad shape and dimensions using the conductor
pattern rather than the aperture of the solder mask of SMD.
It establishes a resist aperture that is larger than the conductor pattern and has a structurein which the base material is exposed in the pad circumference and the surrounding area iscovered by the resist pattern.
(12) Sacrificial terminal
This is a terminal that is set up for the subsidiary purpose of preventing the destruction ofother terminals, and is set up in the case that even if this terminal itself is destroyed there
will be no electrical or mechanical effect on the system overall. Note that it is the floating
conductor so normally it is connected to a ground or power source.
It is sometimes called a dummy pin but in this standard we use this expression because it has
the purpose of protecting or extending the service life of the other terminals.
(13) SMD (solder mask defined) pad
This is a pad structure that defines the pad shape and dimensions using the aperture of thesolder mask (solder resist).
It establishes a resist aperture that is smaller than the conductor and has a structure inwhich the conductor pattern of the pad circumference is covered by the resist.
The expression is used in contrast to NSMD. Do not confuse it with SMD (Surface mounting
Device) which generally refers to surface mounting parts.

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JERG-0-054B(E)(14) Staking
This refers to mechanically fixing of the BGA and CGA package to the PWB using bonding
and attachments.
(15) Underfill
This is similar to staking but mainly organic resin is filled into the gap with the PWB for the
purpose of terminal protection and sealing particularly when mounting on the PWB the parts
formed by the external connection terminal on the bottom surface, such as the flip chip and
BGA package, etc.
(16) Un-melted (BGA/CGA)
This refers to the condition in which the ball of the BGA or the column of the CGA does not
melt with the printed solder paste and therefore is not wet.
(17) Via in Pad / Pad on Via
This is the connection structure of the PWB pattern that forms the soldering pad directly
above the through-hole for the inner layer connection in contract to the Dog-Bone.
It is similar to the “stack via” structure piled up vertically that is seen in build-up boards, inwhich mainly organic resin is filled into the through-hole that goes through the rigid board of
the layer system, and it is plated to form the pad.
(18) Void
This refers to the condition in which cavities and air bubbles occur inside the solder, organic
resin, etc.
In engineering the term “void” refers to a vacuum, and cavities filled with gas are called air
bubbles or pores but as a matter of common practice the term “void” is used with the meaningof something not being where it should be, including air bubbles.
(19) Void ratio
The ratio of the cross-sectional area of voids to the cross-sectional area of the solder joint(including void areas).

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