1. Work Instructions |
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1.1 |
Is there a revision controlled Operator Work Instruction which contains set-up information for the specific product being processed? (Score 0 if any unsigned/undated handwritten instructions or any handwritten instructions more than 48 hrs old) |
1.2 |
Are Work Instructions readily available to the operator and are they followed at Wave? |
1.3 |
Do Set-Up Sheets specify the Solder, the Flux, and the thinners (as applicable) to be used? |
1.4 |
Do Set-Up Sheets specify the Spray Flux parameter settings such as delay, duration, traverse speed, pressure, etc? |
1.5 |
Do Set-Up Sheets specify the Pre-Heater set points and the Solder Pot Temperature and are they the same as those on the machine? |
1.6 |
Do Set-Up Sheets specify the Conveyor Speed and is it the same as that in the program? |
1.7 |
Do Set-Up Sheets specify the Lead Clearance and is it the same as that set by the machine? |
1.8 |
Do Set-Up Sheets specify Wave Type (Chip/Lambda/Omega) to be used? |
1.9 |
Do Set-Up sheets specify the Solder Pot Hot Air Knife Pressure and Temperature settings? |
1.10 |
Do Set-Up sheets specify if the Finger Cleaner must be on? No Finger Cleaner = 0 |
1.11 |
Is the machine Program Name specified on the Work Instruction or set-up sheets? |
1.12 |
Do the all the above wave parameter settings correspond to those settings on the machine? |
1.13 |
Are Generic Wave Set-Up Parameters documented? These are the parameters which are not changed for product changeovers. |
1.14 |
Do these Generic Wave Set-Up Parameters include, pressure settings, conveyor angle, etc. |
2. Machine Capability |
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2.1 |
Is the flux application technology in use suitable for the product being built? |
2.2 |
Is the wave technology in use suitable for the product being built in terms of the ability control critical parameters to achieve desired results? |
2.3 |
Does the wave use a top side pre-heater to ensure PTH barrel fill meets IPC 610 specs given the mass of the board, carrier, and the top hat? |
2.4 |
Are air flow controllers or a centralized control system used to balance exhaust flow rates for each individual exhaust drops? |
2.5 |
Are exhaust flow rate ranges specified and monitored on a regular basis to insure compliance? |
2.6 |
Is Automatic Wave Height control installed to control the laminar wave height? |
2.7 |
Is there a Solder Pot Hot Air Knife installed and used on the wave equipment? |
2.8 |
Is there an automatic Finger Cleaner installed and used on the wave equipment with an appropriated cleaning fluid? No FC = 0 |
2.9 |
Is the machine Program Name revision controlled to show traceability of program changes? |
2.10 |
Is the machine Program Name traceable to the PCB and PCBA part number? |
2.11 |
Is access to the machine program password protected with restricted access? |
2.12 |
Do program changes to critical parameters during machine control remain unsaved unless approved by a technician/engineer? |
2.13 |
Is the safety equipment and protective clothing provided adequate and are they used? Must include boots, apron, gloves, face shield, etc |
3. Flux Application |
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3.1 |
Is flux applied using either a fixed nozzle or moving nozzle spray application method? Any other application method = 0 |
3.2 |
Can the sequence of; detection, delay, trigger, duration, and stop, be clearly explained by a technician? Other method = 0 |
3.3 |
Is the detection, delay, trigger, duration, and stop, controls performing as expected? Other method = 0 |
3.4 |
Is there a feedback link between the conveyor speed and the flux applicator to auto-compensate for changes? Other method = 0 |
3.5 |
Is there an automatic sensor that indicates when a flux drum is near empty? |
3.6 |
Is there a method to determine if the quantity of flux applied to the board to ensure it adequate? Not too much and not too little. |
3.7 |
Is there a test used to check the coverage of flux applied to the board to ensure it is sufficient? |
4. Wave Set-Up |
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4.1 |
Has specifying the Solder Pump Speed value been discontinued as a way to achieve the desired Wave Height? |
4.2 |
Is the relationship between Wave Height set-up and Contact Area/Length known for the product being processed? |
4.3 |
Is there a Quartz Plate available to verify Contact Area/Length achieved for the board being processed? |
4.4 |
Is the documented Contact Area/Length being achieved for the Wave Height set-up used? |
4.5 |
Does the shape of the Contact Area indicate parallelism? |
4.6 |
Does the Contact Length coupled with the Conveyor Speed, achieve the documented dwell time requirement? |
4.7 |
Is there evidence that Contact Area/Length and shape verified after Solder Pot removal and replacement, and maintenance? |
4.8 |
Is there evidence that the Contact Area/Length and shape verified on addition of solder or on adjustment of lead clearance? |
4.9 |
Does the board/pallet exit the Solder Pot in the stagnant area for the set conveyor angle and lead clearance? |
4.10 |
Are all conveyor Fingers in a good state of repair? |
4.11 |
Is the quantity, type and spacing of each Finger design defined for the conveyor? |
4.12 |
Has the pot been set up to run with an intermittent wave so as to reduce dross build up? If gap between subsequent PCBAs too small, score 1 |
4.13 |
Does the level of Dross in the pot suggest that the pot is dedrossed at least once every 8 hours? |
5. Temperature Profile |
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5.1 |
Is there available a Temperature Profile for the product currently being built? |
5.2 |
Is the Temperature Profile assessable and readily available to operators / technicians as and when required? |
5.3 |
Were the Pre-Heat Set Points, Conveyor Speed, and Solder Temperature logged for that Thermal Profile when it was conducted? |
5.4 |
Do the Set Points, Conveyor Speed & Solder Temp written on the Thermal Profile correspond to the current Machine settings? |
5.5 |
Is there available an Engineering based specification to detail the acceptable process window for Temperature Profiles? |
5.6 |
Was the Engineering based spec. derived from the Flux manufacturer’s recommendations but controls to a narrower window? |
5.7 |
Does the product Temperature Profile fall within the Engineering based specification for the process window? |
5.8 |
Does the product Temperature Profile fall within the Engineering based specification for glass transition temperature requirements? |
5.9 |
Can any excursions outside of the process window be justified and supported with hard evidence and logical analysis? |
5.10 |
Does the product Temperature Profile meet the requirements of the SMT components already attached to the PCBA? |
5.11 |
Are the boards used to establish the initial Thermal Profile kept as engineering samples? |
5.12 |
Have at least five thermocouples been used at various points on the board to establish the Thermal Profile? Note* |
5.13 |
Is there a documented and systematic approach used to identify the most appropriate locations to attach the thermocouples? |
5.14 |
Is there evidence that each thermocouple ball was bonded to a board joint using Hi Temp. Solder or Conductive Epoxy? |
5.15 |
Is the top side Temperature Profile low enough to prevent secondary reflow? Must be below 160 degrees C. |
5.16 |
Has a Calibration Profile been established in order to detect machine long term performance degradation? |
5.17 |
Is there a documented frequency for running a Calibration Profile and was it established based upon historical performance data? |
5.18 |
Is there evidence to demonstrate that Calibration Profiles are conducted and that records are up-to-date? |
5.19 |
Is the practice of comparing the current Calibration Profile to the Standardized Calibration Profile used to identify changes? |
5.20 |
Is the current Calibration Overlay/Profile used to determine if a variation in the wave’s thermal characteristics has occurred? |
5.21 |
Is the current Calibration Overlay/Profile used to determine if a variation in conveyor speed has occurred? |
5.22 |
Is there evidence to demonstrate that action was taken when the Calibration Profile was different to the Standard? |
5.23 |
Is a standardized tool, like a WaveRider, used with a standardized profile to conduct a Calibration Profile? |
6. Solder Analysis |
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6.1 |
Is there a documented frequency for conducting Solder Analysis and was this frequency established based upon historical results? |
6.2 |
Is there evidence to demonstrate that Solder Analysis records are up-to-date? |
6.3 |
Does the Solder Analysis results suggest that contaminants in the solder pot are within acceptable levels? |
6.4 |
Is there evidence to demonstrate that action was taken when Solder Analysis results were unsatisfactory? |
7. Manual Inspection |
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7.1 |
Are outputted boards at least sample inspected post wave for wave solder defects as part of machine performance control? |
7.2 |
Are Workmanship Standards defined for soldering, and are they accessible so that machine performance can be measured accurately? |
7.3 |
Is Defect Density Charting used to identify the common location of defects so that actions may be take to eliminate them? This may include addition of solder thieves, pallet/carrier modification, etc. |
7.4 |
Is there evidence of the use of at least sampling X-ray to ensure via penetration and barrel fill are to acceptable standards? |
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