PCBA Quality Process Audit — SMT Pick and Place machine

1. Work Instructions
1.1Is there a revision controlled Operator Work Instruction which contains loading information for the specific product being built? (Score 0 if any unsigned/undated handwritten instructions or any handwritten instructions more than 48 hrs old)
1.2Are Work Instructions readily available to the operator and are they followed at Component Placement?
1.3Are component part numbers and descriptions included on the Work Instructions?
1.4Are component descriptions sufficiently detailed to check at first-article that the correct components are being used?
1.5Is the machine head/slot number for component loading specified for each part number on Work Instructions?
1.6Are the reference designators and the quantity per part number specified on Work Instructions?
1.7Is the component feeder type/size specified on Work Instructions or otherwise for each component package type?
1.8Is the machine Program Name specified on the Work Instruction or line set-up instructions?
2. Component Loading and Verification
2.1Is there an automated bar coded component loading verification aid in order to reduce the probability of incorrect loading? Note*
2.2Are the component loading verification aids hard linked to the placement program so that loading is verified against program data?
2.3Can traceability of component lot codes be demonstrated for critical devices?
2.4Is component loading/changes verified and cross checked by an individual other than the set-up operator at product changeover? Note*
2.5Is a component loading/changes verification log signed by the set-up operator and countersigned by the cross checker before start up? Note*
2.6Is the correct feeder loading base used to facilitate real to feeder loading?
2.7Are first-built boards verified against documentation for missing/misplaced components and for correct component polarity?
2.8Are first-articles conducted using AOI methods and complemented with description verification and value metering?
2.9Are all Resistors & Capacitors measured for a value within the tolerance (one per part number) at first-article & at reel change?
2.10Is a first-article log signed to verify acceptance before start up?
2.11Is the orientation of Tantalum SMT capacitors, Diodes, etc in tape format, standardized and documented for polarity orientation?
2.12Is the IC tray loading polarity standardized for each type of polarity indicator that can be used for each component?
2.13Is loading polarity referenced both from the tray and the component so as to ensure retrayed components are correctly loaded?
3. Nozzles, Feeders, and Tooling
3.1Is there a document which details the standardized nozzle diameter set-up selected for each type of placement equipment?
3.2Are these standardized nozzle diameter set-up documents readily available for when nozzles need to be replaced or changed?
3.3Is there a document which details the range of component XYZ body sizes that each selected nozzle type can successfully place?
3.4Is there a documented requirement to conduct daily nozzle centering and is there evidence that this is done?
3.5Is each feeder identified with its own unique serial number?
3.6Is there a documented and effective Feeder Maintenance Program? Records (s/w or otherwise) must be by Feeder Serial Number.
3.7Are database records maintained for each feeder serial number for the purpose of tracking its maintenance history and performance?
3.8Is feeder maintenance history used to monitor feeder life so that problematic feeders can be removed from the process?
3.9Can it be demonstrated that the number of feeder indexes is counted & monitored for each unique feeder using software or otherwise?
3.10Is this information used to flag that feeder preventative maintenance is required after x number of indexes?
3.11Is there a documented requirement to indicate that Blocks or Support Pins are needed for specific products?
3.12Is the No, location, type and height of Support Blocks/Pins identified on a product by product basis? Score NA if in 3.11 there are not needed.
3.13Are the Support Pin locations identified for each product using templates/tooling or some other effective solution? Comment as above.
4. Moisture Sensitive Devices
4.1Are components stored before loading and after unloading in a manner which prevents damage?
4.2Are the Moisture Sensitive Devices (MSDs) and their sensitivity level readily known to the operator?
4.3Are MSDs time stamped at opening and their exposure time monitored against pre determined limits?
4.4Is there a flag to indicate that the exposure time has been exceed for any given device in a dry box?
4.5Is there a flag to indicate the MSD exposure has expired for any MSD device currently loaded in the placement machines?
4.6Have MSD procedures been updated to reflect the JEDEC standard for MSD control? (J-STD-033A MSD released in July 2002)
4.7Is there evidence of correct implementation of J-STD-0033A for all MSD devices?
4.8Are there MSD procedures in place to ensure MSD shelf life is reduced based on measured Relative Humidity conditions?
4.9Is there a method in place to address the time spent in dry storage and its effect on remaining life based on MS Level and RH Level?
4.10Is it clearly understood that MSD ‘shelf life’ continues to degrade during dry cabinet storage of some MSD devices?
4.11If MSDs are on both sides of a PCBA, is there an effective method to account for time between 1st and 2nd reflow?
4.12Can MSD control be demonstrated for MSD devices that need internal/external pre-programming?
4.13Can MSD control be demonstrated for rejected devices and devices used for rework?
4.14Have MSD recovery methods been defined and adequate for all component types?
4.15Does the control of Moisture Sensitive Components include those components on reels?
4.16Is the baking or hot room storage time and temperature documented and controlled for component recovery?
4.17Has this time and temp been determined based on the component supplier’s guidelines / J-STD-0033A?
4.18Is there evidence to demonstrate that the control process for MSDs is in use and is effective?
5. Machine Capability
5.1Are Component Placement Programs generated from CAD XY coordinate data?
5.2Is there a standardized nomenclature for Shape Code definition?
5.3Can this nomenclature be used to determine the most appropriate shape code to allocate to a given part of given dimensions?
5.4Are localized fiducials used for fine pitch devices when localized component fiducials exist on the board?
5.5Has manual component moving been eliminated given correct CAD, nozzle set-up, Shape Code allocation, local fiducials, Cam speed, etc?
5.6Does the Fine Pitch placement machine have the capability to check lead Coplanarity in xyz?
5.7Does the Fine Pitch placement machine use its coplanarity capability on all leads of 20 mil pitch or less, and all programmed parts?
5.8Does the Fine Pitch placement machine have the capability to check ball arrays? If no such device, score NA.
5.9Does the Fine Pitch placement machine use its ball array verification capability for all BGA devices? If no such device, score NA.
5.10Is the machine Program Name revision controlled to show traceability of program changes?
5.11Is the machine Program Name traceable to the PWB and PCBA part number?
6.1Are outputted boards at least sample inspected pre reflow for placement positional accuracy for machine control purposes?
6.2Is the frequency for this verification defined and documented, and is there evidence to suggest it is followed?
6.3Is there a visual aid available which identifies the populated locations with polarity, and also the no-pop locations?
6.4Is there a placement standard pre reflow to validate placement accuracy for the shape code, nozzle allocation, etc. parameters used?
6.5Is there evidence to demonstrate that action is taken to adjust the machines performance for when this standard is exceeded?
7. Attrition Rates and Rejected Components
7.1Is attrition rate monitoring conducted systematically to ensure feeder and/or nozzle problems are captured at least hourly?
7.2Is there documented evidence to ensure attrition rates are checked and actioned at least hourly to ensure process control?
7.3Is there a specification defined for acceptable attrition rates for the individual feeders?
7.4Is there a specification defined for the maximum allowable number of nozzle skips per machine before it is shut down for repair?
7.5Are these specifications determined based on a percentage combined with the number of placements for a given time period?
7.6Is there evidence to demonstrate that attrition rate monitoring is conducted, effective, and used to make process control decisions?
7.7Is there a documented process for the disposition or reuse of machine rejected components? Rs and Cs must not be reused even for rework.
7.8Are rejected components reviewed and repaired to ensure conformance before reuse, even if only used for rework?
7.9Are there repair blocks available or a lead conditioner in use for repairing ‘real’ Coplanarity rejects? Score 0 if parts not repaired.
7.10Does the re-traying process always ensure that component polarity wrt the tray and the component loading polarity is preserved?
7.11Is there a documented Process Deviation procedure to manage machine skips for hand placement if hand placement is allowed?
8. Process Capability
8.1Has a Process Capability Analyses (PCA) been conducted and the Cpk acceptable for the suite of shape codes in use?
8.2Were shape code allocations, component nozzle allocations, cam speeds, etc. recorded for this PCA?
8.3Are the recorded shape code allocations, component nozzle allocations, and cam speeds, the same as those used today?