3. By customer request, all components can pass a thorough final inspection in our Assembly facility.
PCBA Quality Control
PCBA QC techniques that may be performed during PCB assembly include: 1. Visual Inspections 2. X-ray Inspection 3.AOI Test 4. Electrical Testing, Flying Probe E Test, Bed of Nails Test 5. ICT Test 6. FCT Test
PCB Assembly Quality Control System
X-Ray Inspection for BGA Assembly
Our automated X-ray inspection systems are able to monitor a variety of aspects of a printed circuit board in assembly production. The inspection is done after the soldering process to monitor defects in soldering quality. Our equipment is able to”see” solder joints that are under packages such as BGAs, CSPs and FLIP chips WHERE the solder joints are hidden.
This allows us to verify that the assembly is done right. The defects and other information detected by the inspection system can be quickly analyzed and the process altered to reduce the defects and improve the quality of the final products. In this way not only are actual faults detected, but the process can be altered to reduce the fault levels on the boards coming through. Use of this equipment allows us to ensure that the highest standards are maintained in our assembly.
Components Quality control
To make sure the components to be used are good quality, there are several processes that we follow:
1. An overview of the visual electronic components inspection process includes:
* Packaging examined:
-Weighed and checked for damage
-Taping condition inspected-dented package etc.
-Original factory sealed vs. non-factory sealed
* Shipping documents verified
-Country of origin
-Purchase order and sales order numbers match
* Body marking inspection (faded markings, broken text, double print, ink stamps, etc.)
* Physical conditions inspection (lead bands, scratches, chipped edges, etc.)
* Any other visual irregularities found
Once our visual distribution inspection is completed, products are escalated to the next level-electronic components engineering distribution inspection for review.
2. Engineering Components Inspection
Our highly skilled and trained engineers receive the components for evaluation at a microscopic level to ensure consistency and quality. Any suspect parts or discrepancies that are discovered in the visual inspection process will either be verified or discounted by taking a product sampling of the material/parts.
The engineering electronic components distribution inspection process includes:
* Review visual inspection findings and notes
* Purchase and sales orders numbers verified
* Verification of labels (bar codes)
* Manufacturer’s logo and date log verification
* Moisture sensitivity level (MSL) and RoHS status
* Extensive marking permanency tests
* Review and comparison to manufacturer datasheet
* Additional photos taken and cataloged
* Solderibility Testing, the samples undergo an accelerated ‘aging ‘ process before being tested for solderibility, to take into consideration the natural aging effects of storage prior to board- mounting; In addition to the Engineering Components Inspection we have a higher level of inspection under the customer request.
Detectable defects list
| Defect No. | Defect Description | Selected Inspection Technology(s) | Defect Class | Automated Detection by final prototype |
|---|---|---|---|---|
| 1 | Dry joints | AOI | Soldering | No |
| 4 | BGA voiding | X-ray | Soldering | Yes |
| 5 | BGA bridging | X-ray | Soldering | Yes |
| 6 | BGA tilted | X-ray | Soldering | Yes |
| 7 | BGA missing balls | X-ray | Soldering | Yes |
| 8 | BGA poor wetting | X-ray | Soldering | Not reliable detection |
| 9 | BGA poor reflow | X-ray | Soldering | Yes |
| 10 | Leaded CC poor heel joint | X-ray | Soldering | No |
| 13 | Leaded CC lifted leads | AOI | Soldering | No |
| 14 | SOT SOIC lead lift | AOI | Soldering | Not reliable detection |
| 15 | Solder balls | AOI | Soldering | Yes |
| 16 | PTH solder poor fill | AOI | Soldering | No |
| 17 | PTH poor lead wetting | AOI | Soldering | No |
| 18 | Heat plane delamination | SAM/Active thermography | Board | Yes |
| 19 | Plastic Encapsulated Delamination | SAM/Active thermography | Components | Yes |
| 20 | Chip capacitor crack | SAM/X-ray | Components | Yes |
| 21 | Missing component | AOI | Placement | Yes |
| 22 | Tomb-stoning | AOI | Soldering | Yes |
| 23 | Flipped | AOI | Soldering/Placement | Yes |
| 24 | Tilted | AOI | Placement | Yes |
| 25 | Solder short | Passive thermography | Soldering | Yes |