aqa directive on pcb soldering...
TRANSCRIPT
AQA DIRECTIVE ON PCB SOLDERING PROCESS
07/2020
भभभभ भभभभभ, भभभभभ भभभभभभभभ भभभभभभभ भभभभभभभभ भभभभभभभ भभभभभभभभभभभ / भभभभभभ भभभभभभ भभभभभभ
‘भभ’ भभभभभ, भभभ भभभभभभ -110011 GOVERNMENT OF INDIA, MINISTRY OF DEFENCE
DIRECTORATE GENERAL OF AERONAUTICAL QUALITY ASSURANCE ‘H’ BLOCK, NEW DELHI – 110011
TEL: 011-23011783, FAX: 011-23014395 www.dgaeroqa.gov.in, e-mail: [email protected]
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TABLE OF CONTENTS
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Sl. No.
Contents Page No.
1. Introduction 04
2. Definitions and Brief Description 04
3. Safety & Handling Instructions and Assembly Preparation 06
4. PCB Soldering Process 08
5. Documentation / References 20
6. Conclusion 21
7. Annexure 22
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INTRODUCTION
1. Printed circuit board assembly (PCBA), is the process of soldering or
assembly of electronic components to a printed circuit board (PCB). A
circuit board prior to assembly of electronic components is known as PCB.
Once electronic components are soldered, the board is called Printed
Circuit Assembly (PCA) or Printed Circuit Board Assembly (PCBA).
2. It has been observed during inspection, testing and
exploitationsoldering defect like dry solder, insufficient solder, bridging,
lumps solder, solder cracks etc. have been noticed. These
defects/inadequacies lead to the re-work of modules/boards which
reduces the reliability of the LRUs/equipmentsand affect the Quality and
reliability of the product. Hence, it is more important that controlling the
soldering processis a better method of Quality Assurance than post process
inspection (Assembly Inspection).This Directive is reference document
only the process can be modified depending on specific requirements.
DEFINITIONS AND BRIEF DESCRIPTION
3. Thru-Hole Electronic Components
Electronic componentsthat have leads coming out and are inserted through
tiny holes in the PCB or soldering are called thru-hole electronic components.
The assembly or soldering process for these components include wave
soldering and hand soldering
4. Wave Soldering
A PCB assembly process in which solder in the form of solder bar are put in
a high-temperature bath. This solder remains in the bath in molten form and
forms a wave at very high temperature. The range of temperature depends on
the type of solder.
Wave soldering process includes following steps:
Inserting of electronic components
Flux application
Preheat
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Cleaning
Testing of assembled PCB as per the ATP
Once the wave soldering is done; the PCBA is cleaned and tested. If any
fault or solder joint is found, it is sent for rework, which is generally done
by hand.
5. Hand soldering
Hand soldering is performed in manufacturing units with less work load or in
rework / repair jobs. A good quality soldering station or soldering iron and
solder wire and flux are used in the process.
6. Surface Mount Technology (SMT)
Surface Mount Technology or SMT is a PCB as SMD components don’t have
leads or legs. They are mounted on the surface of the circuit board. The
equipment’s, electronic components and other soldering material used in this
assembly process are different from thru-hole soldering process.
7. Reflow Soldering
This is a process in which a solder paste (a sticky mixture of powdered solder
and flux) is used to temporarily attach one or several electrical components to
their contact pads, after which the entire assembly is subjected to controlled
heat, which melts the solder, permanently connecting the joint. Heating may
be accomplished by passing the assembly through a reflow oven or under an
infrared lamp or by soldering individual joints with a hot air pencil assembly
process for SMD electronic components.
8. Selective Soldering
This is the process ofsoldering components selectivelyin standalone
mode(leaded components) on existing populated printed circuit boards
(PCBs) and modules. Moreover,surface-mount technology (SMT) assembly
processmay damage adjacent component by heat of reflow oven. The selective
soldering process must be sufficiently precise to avoid the damage of existing
surrounding components.
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SAFETY, HANDLING INSTRUCTIONS AND ASSEMBLY PREPARATION
9. For effective monitoring and uniform assembly process across all
assembly houses, reference template document has been prepared
(Annexure-E). The document has been prepared based on experience and
adopting the practices being followed by major electronics assembly
manufacturer.
10. All assembly and inspection operations are to be carried out by trained,
approved Operators as per JST-002 Standard and Inspectors as per IPC-610 D
Standard and DGAQA approval of Inspectors. The signature and stamp of the
operators and inspectors have to be affixed after completion of each
operation.
11. Assembly and other related processes to be carried out inassembly
areas where temperature is maintained at 24° C+/- 2° C & relative humidity
less than 60%.
Note: List of machinery and equipments indicated in the Production Route
Card (PRC) be in line with the production facility. The machine details are
indicative and may vary during actual production.
12. Verification of inputs as per part list &bom (kit inspection)
(a) Verify the parameters as per Kit Inspection Format (Annexure A to D).
(b) Verify the bare Printed Circuit Board (PCB) finish, Part No, Sl. No,
Group A and Group B certificates as per MIL-PRF-55110 or
equivalent standard.
(c)PCB manufacturing date to be indicated in the kit inspection report.
(d) Ensure all SMDs have been inspected as per AQL using 40X as part of
Inward Goods Inspection (IGI).
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13. Collection of kit from stores
(a) All the electronic components to be packed in tubes or trays or
continuous strips and to be kept in Electro Static Device (ESD) covers.
(b) Integrated Circuits (IC’s) with formed Leads to be packed in ESD
Box.(To avoid Transit damage for Leads)
(c) For Moisture sensitive devices, details from the original pack (i.e.
Moisture Sensitive Level (MSL), Baking Details, Storage temperature and
humidity.) to be duplicated on the Moisture barrier bags used for
packing.
(d) ICs, which are moisture sensitive devices and should be packed in
moisture barrier bags and to be kept in de-humidifier.
(e) Verify for Shortage of Components.
(f) Verify for any Transit damage of components and PCB.
14. Storing of launched kit (if kit inspection is not taken up within
onehour)
(a) Store kit in de-humidifier (Relative humidity < 25%) placed in
temperature controlled room.
(b) Printed Circuit Boards (PCBs) and Moisture Sensitive Devices
(MSDs) should be kept in sealed dry packaging in de-
humidifier(Relative humidity 10%) placed in temperature controlled
room.
(c) Record the date of storing of kit.
15. Details of components with multiple batch codes
Enter the list of components having multiple batch codes.
(a) Part No. (b) Batch Codes
16. Identification & Listing of Components with Old Date Codes
(Greater Than 5 Years)
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(a) List the components that are older than 5 years Leaded Components
Part No.Other types of components including chip components Part
No.
(b) Solderability test has to be carried out as per the J-STD 002
(solderability test for components leads, terminations, lugs and
wires) before assembly as per the approved documents by Assembly
department).
17. Collection of Items as per Part List (Pl)
Following parameters are to be verified: –
(a) Part Number of components
(b) Quantity
(c) Documents: Production order, General Assembly, Part List.
(d) Cleared kit offering letter/Memo/Inspection call slip& BOM
verification report
18. MOVEMENT OF MATERIALS TO ASSEMBLY HOUSE
Ensure the following: -
(a) PCBs are in sealed dry packing.
(b) All electronic components are packed in Electro Static Device
(ESD)bags/covers
(c) Moisture sensitive devices are in Moisture Barrier bags
(d) Formed ICs are kept in ESD sensitive transit boxes
PCB SOLDERING PROCESS
19. Marking Mark the module Sl. No. on the rear side of PCB using Epoxy
InkWhite (Part No.) and Catalyst (Part No.) or as per process stdPCB issue
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level traceability has to be marked on the PCB as per Master Drawing Index
issue level.
(Note: Pot life of the mixture to be ensured).
The location of marking is indicated in the drawing.Curing time for the
mixture is 60 minutes at 930 C, Start time, End time, Shelf life expiry date of the
ink used, and Shelf life expiry date of catalyst used.
20. Storing of launched kit (If In case manufacturing not taken-up within
one hour)
Store the kit in de-humidifier (Relative humidity < 25%) placed in
temperature controlled room.PCBs and MSDs should be kept in sealed dry
packaging in de-humidifier (Relative humidity 10%) placed in temperature
controlled room. Endorse date of storing and date of assembly.
21. All assembly and inspection operations are to be carried out by trained
as per J-STD 002 or equivalent approved operators and inspectors having IPC
610 D or equivalent certificate holder only. The signature and stamp of the
operators and inspectors have to be affixed after completion of each
operation.
22. Assembly and other related processes have to be carried out in areas
where temperature is maintained at less than 26 ° C& relative humidity less
than 60%.
23. Pre-heating/baking of PCB
(a) Pre-heat the PCB (Part No.) 1000 C for 10 Hrs to remove moisture
and gaseous pollutants as per the process standard as defined in the
process document.
Note: Check for bow and twist (war page) on the PCB. The bow and
twist should be less than 0.75%. (Ensure prebaked PCBs are taken for
soldering within 3 days of pre-baking under storage condition 200 C and
30% RH).
(b) Date of Pre-Heating PCB shall be endorsed in PRC
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24. Degolding of IC
ICs having gold plated leads are to be De-Gold for better Solderability as per
the process standard.
a) From at least 95% of the surfaces to be soldered of the through-
hole component leads with 2.54 µm [100 µin] or more of gold thickness.
b) From 95% of all surfaces to be soldered of surface mount
components regardless of gold thickness.
c) From the surfaces to be soldered of solder terminals plated with
2.54 µm [100 µin] or more of gold thickness.
25. A double tinning process or dynamic solder wave may be used for gold
removal prior to mounting the component on theassembly
26. Baking of moisture sensitive devices
IC which are having moisture sensitive, carryout the following baking
operation to dry the SMD packages as per J-STD-033801.
27. For different moisture level floor life is as mentioned in table below
shall be followed: -
Level Floor life 1 Unlimited at ≤ 300 C 85% RH
2 1 Year
Temp range 300 C 60% RH
2a 4 Weeks
3 7 Days
4 3 Days
5 2 Days
5a 1 Days
6 Mandatory bake before use. After bake, must be reflowed within the
specified time limit.
28. The moisture sensitive devices which floor life exceeded shall be baked
as per the process document.
29. Tinning of components and solderability test for components
which are more than 5 years old
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(a) For leaded components. Carryout Solderability test for
leaded components as per Process Standard,prior to assembly.
(b) For other types of components. Carryout Solderability test as
per the process document for old components other than leaded
components which are more than 5 years old. If the component passes
the Solderability test, entire batch of component can be used for
production.
30. Mounting of SMD components on top side
(a) Solder paste details:
Use the solder paste as per the specification.
(i) Make:
(ii) Part No.
(iii) Shelf Life expiry date of Solder paste.
(b) Solder paste thawing and softening
Keep solder paste in solder paste softener machine and stir for 3
minutes.
(c) Screen Printing
Screen print the solder paste using stencil in the screen-printing
machine. Squeezing is done once in both forward and reverse direction.
Screen printing machine details are Make, Model and Location. Ensure
the PCB is taken up for reflow soldering within 8 hours of deposition of
solder paste.
(d) Solder paste height verification
Check for solder paste height using Z check meter or equivalent.Solder
paste height should be between 5 +/- 1.0 mil.
(e) Placement of SMD components
Place SMD components using automatic pick and place machine as per
the program detail. Component shall be mounted without obstructing
the terminations of the other components and parts.Ensure that polarity
and part marking is maintained while mounting thecomponent.
Components are to be mounted on PCB top side using pick and place
machine.
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(i) Program number.
(ii) Version.
(iii) Date of carrying out the process:
(iv) Starting time:
(v) Ending time:
Machine details are Make, Model and Location.
Calibration status of (please tick)
Solder Paste softener machine : Yes/No
Screen printing machine : Yes/No
Screen print height measurement machine : Yes/No
Automatic Pick and place machine : Yes/No
Note: Clean the solder stencil using Isopropyl Alcohol (IPA) and blow
with high pressure compressed air before and after screen printing.
31. Visual inspection
Inspect the boards where components have been placed with40 X magnifier to
check for component missing, wrong value, and polarity reverse, extra
components, marking erased on the components and PCB.
32. Re-Flow Soldering
If the reflow soldering for the above board is to be carried out for the first
time, arrive at the reflow solder profile after carrying out trails on 3 boards on
different days and if it is already arrived, follow the steps indicated below,
Re-flow solder as per the Thermal profile indicated below:-
Program number:
Version:
Temp @ Zone 1:
Temp @ Zone 2:
Temp @ Zone 3:
Temp @ Zone 4:
Temp @ Zone 5:
Temp @ Zone 6:
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Temp @ Zone 7:
Temp @ Zone 8:
Conveyer speed:
Reflow profile data will be arrived after conducting trails. Ensure reflow
soldering is carried out within 8 Hrs of deposition of solder paste.
Date and Time of carrying out Reflow soldering:
Reflow machine details are follows:-
Make:
Model:
Location:
Note: Thermal profiler to be used for each batch to validate the thermal
profile obtained during the approval of the above reflow profile.
Thermocouple point to be soldered at Top side and resister pack (R-
PACK) as per the work instruction.
Thermal profile obtained above should be compared with original
profile (reference board).
Re-flow profile used for soldering are to be attached to Production Root
Card (PRC) of each assembled PCBs.
33. Cleaning
Clean the PCB by dipping in Isopropyl Alcohol (IPA) with ESD brush to remove
flux residues and other contaminations within 30 minutes of soldering.
34. Automatic Optical Inspection (AOI)
AOI machine details are as follows: -
Make:
Model:
Location:
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Following details to be checked in AOI:-
Component placement:
Component orientation:
Component marking as per BOM:
QM to maintain Assembly inspection report:
Work Instruction to be followed:
Assembly Inspection Report (AIR) No:
35. Mounting of SMD components on rear side
The procedure followed for mounting of SMD Components as per above para
No. ‘G’ should be followed for rear side also.
36. Manual Soldering (Rework)
Carryout rework manually asper the work instruction.
37. Re-Inspection
Verify whether rework has been carried out and parts can be released for next
operation.
38. Mounting of Connectors
(a) Pre Tin the leads of the connector by dipping in solder bath.
(b) Mount the Connectors. Apply torque on screw as per the GA and
clean the solder joints with IPA solution.
39. Lead forming of ICs
Form leads for IC using lead forming tool for IC, Use Tool No.----- and Work
Instruction------
40. Pre Baking Of ICs
The ICs which are to be soldered manually in isolation (which cannot be
carried out reflow soldering), following procedure to be followed:
Bake the IC No. -----
Time started --------
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Time completed ------
41. Apply Loctite No
Apply Loctite No. --- where ICs is bonded to the PCB as per Work
Instruction No. --- .
Loctite No. ---- adhesive comes in 2 parts
Adhesive (P/N --- )
Activator for Adhesive (P/N ---- )
Apply Loctite by following instruction in the area between ICs and PCB.
(i) Bond surfaces should be clean and free from grease.
(ii) Use applicator to apply the activator to the surface to be bonded.
(iii) After the solvent evaporates, the active ingredients will appear
wet, and will remain active for up to 2 hours after application,
Contamination of the surface before bonding should be prevented.
(iv) Apply adhesive to the un-activated surface.
(v) Secure the assembly, and wait for the adhesive to fix
(approximately 5 minutes) before any further handling. Full cure occurs
in 24 hours.
(vi) The amount of adhesive applied to the part should ensure a
minimum coverage of 90% of the area under the device and should be in
contact with the bottom of the part.
(vii) The dispensing of application of the adhesive should be done as to
minimize air entrapment.
(viii) Ensure the adhesive should not interfere with the footprint pads
or the device leads.
(ix) Shelf life of Adhesive and Activator shall be ensured.
42. Potting of Vibration Sensitive Components
Pottingof vibration sensitive components to be carried out by using MIL
approved RTV compound as per the process document.
43. Alignment and Spot Soldering of ICs
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Ensure curing time of 24 hours is completed for the adhesive before taking up
for soldering. Also, care should be taken so that the temperature on the
adhesive does not cross 1250 C while soldering.
44. Manual soldering
Manual soldering of ICs under 10X magnification as per the Process Standard
and Work Instruction.
45. Jumpers and Short Connections Zero Ohm Components
Solder the jumpersand Pads of Components as per General Assembly (GA) and
Work Instruction. Nos. of Jumpers will be decided by designer and will be
approved by RCMA with DGAQA consultation. The same will be reflected in GA
drawing.
46. Cleaning
Clean the boards with IPA solution using ESD brush within 30 minutes of
soldering and record soldering completion time&cleaningtime.
47. Physical Inspection
Verify the following under 40X magnification or as mentioned in
the process standard.
Soldering quality.
Soldering defects.
Component damage.
Foreign Object Debary (FOD).
QM to maintain Assembly Inspection Report.
48. Application of jet melt
Apply Jet Melt on to IC as per work instruction and record Start Time ; End
Time and Shelf life expiry period.
49. Mounting of card lock
(a) Mount the card lock on card lock slot.
(b) All screw should be mounted using Loctite.
(c) Apply Torque as specified in process standard.
(d) Record Shelf life expiry period of Loctite.
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50. Test as per ATP
PCBA testing has to be carried out as per ATP.
51. Screening of assembled PCBs which are having; industrial grade
components
The PCBs/Modules having Industrial Grade Electronics Components shall be
screened as per the JSG 0667: 2005 (Reaffirmed 2011). Following screening
operation carried out:
(a) Stabilization bake at + 850 C for 24 Hrs.
(b) Thermal Shock.Thermal shock at - 400 C and + 850 C with 30
minutes dwell time. Carryout for 10 cycles and ensure transfer time is 2
minutes.
(c) Power-on Burning. PCB shall be maintained at maximum rated
operating temperature with tolerance +- 50C for 48 Hrs in power ON
condition and functional test to be carried out every five hours.
52. Rework
Carryout rework as per assembly inspection report.
53. Re-Inspection
Verify whether rework has been carried out and parts can be released for next
operation.
54. Cleaning
Clean the PCB using Iso Propyl Alcohol (IPA) as per Process Standard (PS).
The three tank cleaning system as detailed below:
(i) Dip the PCB assembly in ‘Tank-1’ for 5 minutes.
(ii) Wear antistatic gloves and clean the PCB using antistatic brush.
(iii) Shift the PCB assembly to ‘Tank-2’ which has in dipped condition
for 3 minutes.
(iv) Dip the PCB assembly in ‘Tank-3’ for 3 minutes.
(v) Dry the PCB in clean air circulated oven 55 (+/- 5)0 C.
Note: The solvent in Tank-1 has to be discarded when the boards failed
to meet the resistivity test of solvent extract or sodium chloride salt
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equivalent ionic contamination test as specified in QS. Cleaning of the
PCBs also can be carried using De-Greasing Machine.
55. Resistivity check
Carry out the resistivity check on one representative sample of each printed
wiring board assembly type processed during each production shift.Check as
per Quality Standard (QS), QM department to maintain the report/record after
carrying out the test.
56. Conformal Coating Process
Mask the connectors and card lock mounting surface with masking tape and
carry out Conformal Coating as per Process Standard. Record the following
parameters:
Date of process;Start time;End time &Curing temperature
57. Removal of masking
Remove the masking done for conformal coating carefully without disturbing
the Coating.
58. Conformal coating inspection
Verify following parameters: -
(a) Coating coverage (This checked under UV lamp).
(b) Peel off, Blow Holes and Bubbles under 4X magnification.
(c) Coating Thickness using instrument.
(d) Masking area as indicated in drawing are not coated with the
coating material.
(e) Wavy pattern to be verified.
(f) QM department to maintain Inspection Report.
59. Functional testing
Module/PCB to be tested as per ATP and Testing department to maintain
Testing Reports / Records.
60. X-ray Inspection
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Carry out X-ray inspection for checking the soldering quality and to verify any
shorts in the following devices.
Integrated Circuits (ICs) including BGAs.
Crystal Oscillator.
Resistor Network.
61. High resolution photo
High resolution photo to be taken and soft copy of the same to be maintained
by Quality Manager (Assembly Inspection) [QM (AI)] Department.
62. PCB handling and transportation
The following procedure has to be followed for handling the PCB assemblies
during transportation
(a) Each PCB assembly should be packed and vacuum sealed in
antistatic aluminium foil cover with desiccant.
(c) Antistatic box with partition for holding one PCB assembly per
partition with adequate antistatic foam or bubble sheet to give
cushioning effect.
DOCUMENTATION & REFERENCES
All the documents used for manufacturing of the above PCB assembly including PRC to be scanned and softcopy of the same to be maintained by QM (AI) Department. Check list Kit Inspection Document. Production Order, General Assembly (GA), Part List, ATP for Modules / LRUs BGA. Part No Process Standards List of documents that will be available as part of manufacturing the above PCB assembly (Data Pack) Kit Inspection Report. Screening Report of ICs.
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Reflow profiles followed for component side and solder side. AOI report after reflow soldering on component side and solder Side. Report of visual inspection using 40X magnification. Inspection report after manual soldering of ICs and connectors. X-ray inspection report. Inspection report after thermal shock. Test reports for the tests conducted as per ATP. Acrylic conformal coating inspection report. Filled PRCs, with signature and seal of approved operators andinspectors. High resolution photos of assembled PCBs (both sides) onebefore conformal coating and other before dispatch. All AIRs pertaining to the non-conformities observed duringproduction. Consolidated List of all non-conformities (NCR No. / AIR No.)observed during Material Inspection, Assembly Inspection andtesting. Certificate from Head, Quality Manager (QM) for having verified the disposition on Non-Conformances (NCs).
CONCLUSION
The document has brought out systemic procedures / practices that will help
all the stakeholders to ensureQuality Assurance (QA) during Soldering Process
with documentary evidence that specified quality requirements have been
met. Though, the primary responsibility of ensuring the quality of the outgoing
product will continue to rest with the main contractor. These procedures will
enhance the quality of final product. Strict adherence to these procedures is
expected to further enhance the confidence of our esteemed customers of
Armed Forces for keeping our flying machines in the highest order of
operational readiness.
NOTE: Suggestions for further improvement/amendment in this document
are welcome and may be addressed to the following;
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Directorate General of Aeronautical Quality Assurance
(Attention: Director / Tech Coord)
‘H’ Block, New Delhi-110 011
E-mail: [email protected]
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Annexure ‘A’
KIT INSPECTION FORMAT (ELECTRICAL/ELECTRONICS)
REQUIREMENT AS PER BILL OF MATERIAL (BOM)
BOM Sl. No Part No. / Type No.
Description OEM /
Manufacturer Part No.
Qty. / Set Lead Finish
Component Category
(MIL / QML / QPL / LCSO /
Industrial / Automotive
Component grade /
Operational Temp and
Storage
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Annexure ‘B’
KIT INSPECTION FORMAT FOR ELECTRONICS COMPONENTS
Data of received part
GR No
Manufacturer
Manufacturer
Part No. marking
on the item/ Pack/ COC
On item marking
Date code/ batch code
COC (OEM/ OEM
Franchises
Test reports/ Material Analysis Report
Qty. / offered/c
hecked
Expiry Date
ESD or
Non ESD
MSD of
Non MSD
ROHS or Non ROHS
Pack. Type
Lead Finish/ Solder
coated/Gold
plated / Surface Finish
and Thickne
ss
Nos. of
Pins
Visual Inspection / Testing at MI
Visual Inspection / Corrosion /
rust / pitting / scratches /
cracks
Dimension/Size
Remarks
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Annexure ‘C’
KIT INSPECTION FORMAT (MECHANICAL)
Raw Material
Batch No.
Material Specification /
Material Code
Spectrometric
Verification of Material
Manufacturing
Process of Items
Heat Treatment/brazing
annealing/forging
etc. of the item,
Process and Batch
No.
Mechanical properties
test on samples
(heat treatment)
Non Destructive Testing on
the component
s
Micrometric Examination
Surface Treatment
Functional / Fitment
Test
Any special
test
Final acceptance / Itemization
/ Tag Generation
Preservation Details / Tag Endorsement
Visual Inspection
before assembly / detail part inspection
for assembly
Remarks
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Annexure ‘D’
KIT INSPECTION FORMAT (CONSUMABLES) Raw
Material Batch No.
Material Specification / Material Code
Part No. Nomenclature
Date of Manufacturing
Shelf life/Date of Expiry
Qty per packing
Total packed Qty
Storage Conditions
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Annexure ‘E’
PCB ASSEMBLY TEMPLATE
Sl. No.
Operation Number
OPERATION Assembly carried out by (sign & date with
apex approved
stamp)
Verified by QM
(AI) (sign & Date
with apex approved
stamp)
Remark
1. KIT INSPECTION (AQA Directive 06/2018) As per the Appendix A ; B ; C & D
2. STORING OF LAUNCHED KIT (IF IN CASE MANUFACTURING NOT TAKENUP WITHIN ONE HOUR)
Store kit in de-humidifier (Relative humidity < 25%) placed in temperature controlled room.
PCBs and MSDs should be kept in sealed dry packaging in de-humidifier (Relative humidity 10%) placed in temperature controlled room.
1. Date of storing : __________________
2. Date of assembly : __________________
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Annexure ‘E’ Sl. No.
Operation Number
OPERATION Assembly carried out by (sign & date with
apex approved
stamp)
Verified by QM
(AI) (sign & Date
with apex approved
stamp)
Remark
3. DETAILS OF COMPONENTS WITH MULTIPLE BATCH CODES Enter the list of components that are offered to Kit Inspection with multiple batch
codes
1.P/n : …………………………………….
Batch Codes : …………………………………………..
1.P/n : …………………………………….
Batch Codes : ……………………………………………
1.P/n : …………………………………….
Batch Codes : …………………………………………
4. IDENTIFICATION AND LISTING OF COMPONENTS WITH OLD DATE CODES (GREATER THAN 5 YEARS)
List the components that are older than 5 years Leaded Components –
P/n :_______________________________
Other types of components including chip components
P/n :_______________________________
(Solderability test has to be carried out before assembly as per operation no: -
----- by Assembly department)
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Annexure ‘E’
Sl. No.
Operation Number
OPERATION Assembly carried out by (sign & date with
apex approved
stamp)
Verified by QM
(AI) (sign & Date
with apex approved
stamp)
Remark
5. COLLECTION OF ITEMS AS PER PART LIST (PL)
Following parameters are to be verified,
1. Part Number of components
2.Quantity
3. Documents: Production order, General Assembly, Part List.
4.QA cleared kit inspection report
6. MOVEMENT OF MATERIALS TO ASSEMBLY HOUSE Ensure the following
a. PCBs are in sealed dry packing.
b. All electronic components are packed in ESD sensitive covers
c. Moisture sensitive devices are in Moisture Barrier bags
d. Formed ICs are kept in ESD sensitive transit boxes
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Annexure ‘E’ Sl. No.
Operation Number
OPERATION Assembly carried out by (sign & date with
apex approved
stamp)
Verified by QM
(AI) (sign & Date
with apex approved
stamp)
Remark
7. MARKING
Mark the module Sl. No. ________ on the rear side of PCB using Epoxy Ink white
(P/n------ ) and Catalyst )P/n ----- )
PCB issue level traceability has to be marked on the PCB as per Master Drawing
Index issue level.
(Note : Pot life of the mixture : 4 Hours )
The location of marking is indicated in the drawing.
Curing time for the mixture is 60 minutes at 93 Degree centigrade.
Start time : ______________ End time : _________________
Shelf life expiry date of the ink used : _______________
Shelf life expiry date of catalyst used : ______________
8. PRE-HEATING OF PCB
Pre-heat the PCB (Part No. ---- ) for 1000 C for 10 hours to remove moisture and gaseous pollutants as per process standard (PS) Quality notification no
Note : Check for bow and twist (war page) on the PCB. The bow and twist should be less than 0.75%. Ensure prebaked PCBs are taken for soldering within 3 days of pre-baking under storage condition 200 C and 30% RH. Date of Pre Heating PCB:
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Annexure ‘E’
Sl. No.
Operation Number
OPERATION Assembly carried out by (sign &
date with apex
approved stamp)
Verified by QM
(AI) (sign & Date
with apex
approved stamp)
Remark
9. DEGOLDING OF ICs ICs is having gold plated leads Carryout Manual De-Golding on IC as per the process standard
10. BAKING OF MOISTURE SENSITIVE DEVICES IC which are having moisture sensitive, carryout the following
Bake operation to dry the SMD packages as per J-STD-033B01
IC which are having moisture sensitive level 3 and has a floor life of 168 hours take
out of moisture barrier bag at factory ambient temperature 300 C / 60 RH.
Bake the IC to 1250 C for 7 hours, if the floor life has been exceeded by ≤ 72 hours
OR
Bake the IC to 1250 C for 96 hours, if the floor life has been exceeded by > 72 hours
Baking Start Time : -----
Baking End Time : ------
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Annexure ‘E’ Sl. No.
Operation Number
OPERATION Assembly carried out by (sign &
date with apex
approved stamp)
Verified by QM
(AI) (sign & Date
with apex
approved stamp)
Remark
11. TINNING OF COMPONENTS AND SOLDERABILITY TEST FOR COMPONENTS WHICH ARE MORE THAN 5 YEARS OLD For leaded components: Carryout Solderability test for leaded components as per process standard prior to assembly (Sample component can be assembled on a trial board also). If the components are unable to be soldered properly, they are to be tinned and soldered during assembly. A record of the tinning of these components to be maintained. For other types of components: Carryout Solderabilitytest for all components other than leaded components which are more than 5 years old. If the component passes the Solderability test, entire batch of component can be used for production.
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Annexure ‘E’ Sl. No.
Operation Number
OPERATION Assembly carried out by (sign &
date with apex
approved stamp)
Verified by QM
(AI) (sign & Date
with apex
approved stamp)
Remark
12 MOUNTING OF SMD COMPONENTS ON TOP & REAR SIDE
(a) Solder paste details: Use the following solder paste Make:- ---------------, part number ---------- (combination Sn63, Pb37 with no-clean formula) Flux content – 10%, type III Shelf life expiry date of Solder paste : _______________
(b) Solder paste thawing and softening: Keep solder paste in solder paste softener machine and stir for 3 minutes. Solder paste softener machine details are as follows,
Make : ---------------- , Model : ----------------, Location: ---------------
(c) Screen printing: Screen print the solder paste using stencil (stencil Part no: -----) in screen printing machine. The profile details are as indicated below,
Program number:………………………………. Squeeze pressure : ……………………………….
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Annexure ‘E’ Sl. No.
Operation Number
OPERATION Assembly carried out by (sign &
date with apex
approved stamp)
Verified by QM
(AI) (sign & Date
with apex
approved stamp)
Remark
Squeezing is done once in both forward and reverse direction. Screen printing machine details are as follows,
Make : ---------------- , Model : ----------------, Location: ---------------
Ensure the PCB is taken up for reflow soldering within 8 hours of deposition of solder paste
(d) Solder paste height verification: Check for solder paste height using Z check meter or equivalent . Solder paste height should be between 5 +/- 1.0 mil
Solder paste height measured is _____________________
(e) Placement of SMD components: Place SMD components using automatic pick and place machine. The program details as indicated below Component to be mounted without obstructing the terminations of the other components and parts. Ensure that polarity and part marking is maintained while mounting the component as per GA and Process standard. Components are to be mounted on PCB top side using pick and place machine. Program number : ----------------------------- Version :------------------------------- Date of carrying out the process : ------------------------
Starting time : --------------------------- Ending time : ---------------------------
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Annexure ‘E’
Sl. No.
Operation Number
OPERATION Assembly carried out by (sign &
date with apex
approved stamp)
Verified by QM
(AI) (sign & Date
with apex
approved stamp)
Remark
Pick and place machine details are as follows, Make : ---------------- , Model : ----------------, Location: -------------- Calibration status of (Please tick)
Solder Paste softener machine : YES / NO
Screen printing machine : YES / NO
Screen print height measurement machine : YES / NO
Automatic Pick and place machine : YES / NO
Note : Clean the solder stencil using Iso Profile Alcohol (IPA) and high pressure compressed air before and after screen printing .
13. VISUAL INSPECTION Inspect the boards where components have been placed with 40 x magnifier to
check for component missing, wrong value, polarity reverse, extra component
places, wrong orientation, damaged components, marking erased on the
components and PCB.
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Annexure ‘E’ Sl. No.
Operation Number
OPERATION Assembly carried out by (sign &
date with apex
approved stamp)
Verified by QM
(AI) (sign & Date
with apex
approved stamp)
Remark
14. RE-FLOW SOLDERING: If the reflow soldering for the above board is carried out for the first time, arrive at the reflow solder profile after carrying out trails on 3 boards on 3 different days and if it is already arrived, follow the steps indicated below Re-flow solder as per the Thermal profile indicated below , Program number : --------------------------- Version : ------------------------------- Temp @ Zone 1 : Temp @ Zone 2 : Temp @ Zone 3 : Temp @ Zone 4 : Temp @ Zone 5 : Temp @ Zone 6 : Temp @ Zone 7 : Temp @ Zone 8 : Conveyer speed :
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Annexure ‘E’
Sl. No.
Operation Number
OPERATION Assembly carried out by (sign &
date with apex
approved stamp)
Verified by QM
(AI) (sign & Date
with apex
approved stamp)
Remark
Reflow profile data will be arrived after conducting trials. Ensure reflow soldering is carried out within 8 hours of deposition of solder paste. Date & Time of carrying out Reflow soldering : _________ Reflow machine details are as follows, Make : ---------------- , Model : ----------------, Location: --------------- Note:- Thermal profiler to be used for each batch to validate the thermal profile obtained during the approval of the above reflow profile. Thermocouple point to be soldered at following locations Top side and R-PACKs Thermal profile obtained above should be compared with original profile. Re-flow profile used for soldering are to be attached to Production Root Card (PRC) of each assembled PCBs
15. CLEANING Clean the PCB by dipping in Iso- Propyl Alcohol with ESD brush toremove flux residues and other contaminants within 30 minutes ofsoldering.
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Annexure ‘E’ Sl. No.
Operation Number
OPERATION Assembly carried out by (sign &
date with apex
approved stamp)
Verified by QM
(AI) (sign & Date
with apex
approved stamp)
Remark
16. AUTOMATIC OPTICAL INSPECTION AOI machine details are as follows, Make : ---------------- , Model : ----------------, Location: --------------- Following details to be checked in AOI, 1. Component placement. 2. Component orientation 3. Component marking as per BOM QM to maintain Assembly inspection report
Work Instructions to be followed.
Assembly Inspection Report (AIR) No.-----------------------------
17. VISUAL INSPECTION
Inspect the boards where components have been placed with 40 x magnifier to
check for component missing, wrong value, polarity reverse, extra component
places, wrong orientation, damaged components, marking erased on the
components and PCB.
Assembly Inspection Report (AIR) No : _____________________
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Annexure ‘E’
Sl. No.
Operation Number
OPERATION Assembly carried out by (sign &
date with apex
approved stamp)
Verified by QM
(AI) (sign & Date
with apex
approved stamp)
Remark
18. MANUAL SOLDERING
Carryout rework as per assembly inspection report AIR No :_______________
19. RE-INSPECTION
Verify whether rework has been carried out and parts can be released
for next operation.
20. MOUNTING OF CONNECTORS
(a) Pre Tin the leads of the connector by dipping in solder bath
(b) Mount the connector by using Screws and Washers. Apply specified torque on screw as per GA/Process Standard/Work Instruction. Solder the connector on to the PCB as per GA/PS/WI and clean the solder joints with I P A solution.
21. PRE BAKING OF ICs
Bake the IC at 1250 C for 48 hours
Time started : __________________
Time completed : _________________
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Annexure ‘E’
Sl. No.
Operation Number
OPERATION Assembly carried out by (sign &
date with apex
approved stamp)
Verified by QM
(AI) (sign & Date
with apex
approved stamp)
Remark
22. LEAD FORMING OF ICs
Form leads for IC using lead forming tool
For IC , USE TOOL ( No : ------ ) and Work Instruction No.----------------------
23. ALIGNMENT AND SPOT SOLDERING OF IC
Ensure curing time of 24 hours is completed for the adhesive before taking up for
soldering. Also, care should be taken so that the temperature on the adhesive does
not cross 125 degree centigrade while soldering.
24. MANUAL SOLDERING OF under 10 x magnification IC
Manually solder ICs under 10 x magnification, and ICS used on to the
board using Item ( P/n : ----) and RMA flux ( P/n -----). Avoid swapping of ICs,
which are having same package and same part no. Mask the connectors which are
close to the ICs.
25. JUMPERS AND SHORT CONNECTIONS ZERO OHM COMPONENTS
Solder the wire of item no: (P/n:----) across the pads of components
Solder the wire of item no : (P/n: -----) manually as per General Assembly drawing
(GA).
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Annexure ‘E’ Sl. No.
Operation Number
OPERATION Assembly carried out by (sign &
date with apex
approved stamp)
Verified by QM
(AI) (sign & Date
with apex
approved stamp)
Remark
26. APPLY LOCTITE NO. ---------
Apply loctite No. ----- where ICs is bonded to the PCB as per Work Instruction. Loctite No. ----------- adhesive comes in 2 parts Adhesive (P/n : ---------------------) Activator for Adhesive ( P/n : ------------------------) Apply Loctite No.----- by following the below instruction in the area between ICs and the PCB a. Bond surfaces should be clean and free from grease. b. Use applicator to apply the activator to the surface to be bonded. c. After the solvent evaporates, the active ingredients will appear wet, and will remain active for up to 2 hours after application. Contamination of the surface before bonding should be prevented. d. Apply adhesive to the inactive surface. e. Secure the assembly, and wait for the adhesive to fix/bond (approximately 5 minutes) before any further handling. Full cure occurs in 24 hours. f. The amount of adhesive applied to the part should ensure a minimum coverage of 90 % of the area under the device and should be in contact with the bottom of the part. g. The dispensing or application of the adhesive should be done as to minimize air entrapment. h.Ensure the adhesive should not interfere with the footprint pads or the device leads . Shelf life of Adhesive : ________________________ Shelf life of activator : ________________________
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Annexure ‘E’
Sl. No.
Operation Number
OPERATION Assembly carried out by (sign &
date with apex
approved stamp)
Verified by QM
(AI) (sign & Date
with apex
approved stamp)
Remark
27. CLEANING
Clean the boards with IPA solution using ESD brush within 30 minutes of soldering.
Soldering completion time : __________________
Cleaning time : __________________
28. PHYSICAL INSPECTION
Verify the following under 40x magnification,
1. Soldering quality
2. Soldering defects.
3. Component damage.
4. Foreign Object Debary (FOD).
QM to maintain Assembly inspection report
AIR No : ___________
29. REWORK
Carryout rework as per assembly inspection report
30. RE-INSPECTION
Verify whether rework has been carried out and parts can be released for next operation.
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Annexure ‘E’ Sl. No.
Operation Number
OPERATION Assembly carried out by (sign &
date with apex
approved stamp)
Verified by QM
(AI) (sign & Date
with apex
approved stamp)
Remark
31. APPLICATION OF JET MELT
Apply Jet Melt on to IC as per work instruction: Starting time : ____________________ Ending Time : _____________________ Shelf life expiry period : ________________________
32. MOUNTING OF CARD LOCK
1. Mount the card lock on card lock slot.
2. All screws should be mounted using Loctite no.---- (Make: ----------).
3. Torque applied as specified in process standard.
Shelf life expiry period of Loctite : ______________________
33. REMOVAL OF MASKING Remove the masking done for conformal coating carefully without disturbing the coating.
34. X RAY INSPECTION
Carry out X-ray inspection for checking the soldering quality and to verify any
shorts in the following devices
Integrated Circuits
Crystal Oscillator
Resistor Network
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Annexure ‘E’
Sl. No.
Operation Number
OPERATION Assembly carried out by (sign &
date with apex
approved stamp)
Verified by QM
(AI) (sign & Date
with apex
approved stamp)
Remark
35. MOVEMENT OF PCB ASSY FROM ASSEMBLY HOUSE
The following procedure has to be followed for handling the PCB assemblies during
transportation
a. Each PCB assembly should be packed and vacuum sealed in antistatic aluminium
foil cover with desiccant.
b. Antistatic box with partitions for holding one PCB assembly per partition with
adequate antistatic foam or bubble sheet to givecushioning effect.
36. PHYSICAL INSPECTION
Following verifications done under 40x magnification,
1. Component damage.
2. FOD.
QM to maintain Assembly inspection report
AIR No : _______________
37. TEST AS PER ATP
To be verified by Testing personnel
Card testing has to be carried out as per ATP Document No. ; Issue No. and Date
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Annexure ‘E’ Sl. No.
Operation Number
OPERATION Assembly carried out by (sign &
date with apex
approved stamp)
Verified by QM
(AI) (sign & Date
with apex
approved stamp)
Remark
38. SCREENING OF assembled PCBs which are having; INDUSTRIAL GRADE components. Industrial Grade Electronics Components shall be screened as per the JSG 0667: 2005 (Reaffirmed 2011). Following screening operation carried out: (a) Stabilization bake at + 850 C for 24 Hrs.
(b) Thermal Shock: Thermal shock at - 400 C and + 850 C with 30 minutes dwell time. Carryout for 10 cycles and ensure transfer time is 2 minutes.
(c) Power-on Burning: PCB shall be maintained at maximum rated operating temperature with tolerance +- 50 C for 48 Hrs in power ON condition and functional test to be carried out every five hours.
Annexure ‘E’
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Sl. No.
Operation Number
OPERATION Assembly carried out by (sign &
date with apex
approved stamp)
Verified by QM
(AI) (sign & Date
with apex
approved stamp)
Remark
39. RESISTIVITY CHECK
Carry out the resistivity check on one representative sample of each printed wiring
board assembly type processed during each production shift.
Check as per Quality Standard (QS) / Process Standard (PS).
QM department to maintain the report / record after carrying out the test
40. CONFORMAL COATING PROCESS
Mask the connectors and card lock mounting surface with masking tape (P/n ---) as
per details given in the GA.
Setting :
Mix Coating material (Item no: ---) and thinner (Item no : ---) in the ratio 1:1.
Check for Viscosity. Ensure Viscosity 18 +/-4 Sec in Ford cup no 04 (100 ml).
Spray the mixture on a test sample / aluminium plate from a distance of 150 to 200
mm (Air pressure 7 psi).
Allow the board to air dry for 10 min and cure (@ 75 Deg +/- 3 Deg, 30 mins for
Humiseal material P/n : --- and 60 +/- 3 Deg, 45 mins for Conap material, P/n : -)
Spray to the other side and repeat.
Finish shall be smooth, homogeneous and free from defects like blisters, pin holes,
peeling etc. Only after obtaining satisfactory results, production part should be
taken up.
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Annexure ‘E’ Sl. No.
Operation Number
OPERATION Assembly carried out by (sign &
date with apex
approved stamp)
Verified by QM
(AI) (sign & Date
with apex
approved stamp)
Remark
41. CLEANING
Clean the PCB using Iso Propyl Alcohol (Part no ----) IR grade in three tank cleaning
system as detailed below.
1. Dip the PCB assembly in ‘Tank 1’ for 5 mins.
2. Wear antistatic gloves and clean the PCB using antistatic brush.
3. Shift the PCB assembly to ‘Tank-2’ which has in dipped condition for 3 mins.
4. Dip the PCB assembly in Tank-3 for 3 mins.
5. Dry the PCB in clean air circulated oven 55( +/-5 )deg ( As per Process Standard
(PS )
Note : The solvent in Tank 1 has to be discarded when the boards failed to
meet the resistivity test of solvent extract or sodium chloride salt equivalent
Ionic contamination test as specified in QS. Cleaning of the PCBs also can be carried
using De- Greasing Machine
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Annexure ‘E’
Sl. No.
Operation Number
OPERATION Assembly carried out by (sign &
date with apex
approved stamp)
Verified by QM
(AI) (sign & Date
with apex
approved stamp)
Remark
42. CONFORMAL COATING INSPECTION
Following verifications are to be done
1. Coating coverage (This checked under UV lamp)
2. Peel off, Blow holes and bubbles under 4x magnification.
3. Coating Thickness using instrument
4. Masking area as indicated in drawing are not coated with the coating material.
QM department to maintain Inspection report
43. FUNCTIONAL TESTING
Module is tested as per ATP No.---------------------------------
Testing department to maintain Testing reports / records
44. HIGH RESOLUTION PHOTO
High resolution photo to be taken and soft copy of the same to be maintained by
QM (AI) Dept.
All the documents used for manufacturing of the above PCB assembly including PRC
to be scanned and softcopy of the same to be maintained by QM (AI) Dept.