PCB Assembly Test
- We fully comprehend that poor quality products would cause our customers to suffer significant financial loss and will harm both our reputation and that of our clients, thus we go through a number of quality assurance measures before shipping any of our boards to ensure their quality.
- These testing methods include:
- Visual Inspection,
- X-Ray Inspection,
- AOI Inspection,
- Voltage Test,
- Chip Programming,
- ICT test (In-circuit test), and
- Functional test (test software and instructions need to be supplied).
Automated Optical Inspection (AOI)
| Range | Tolerance |
|---|---|
| Accuracy | ±0.0024mm |
| Speed | 5in²/sec(60FOV/sec) |
| PCB Max size | 400mm*330mm |
| Available package | 01005 and fine pitch |
| Defect Type | AOI | |||||||||||||||
| Components | Lifted lead | √ | ||||||||||||||
| Missing components | √ | |||||||||||||||
| Misaligned/Misplaced components | √ | |||||||||||||||
| Soldering | Open circuits | √ | ||||||||||||||
| Solder bridges | √ | |||||||||||||||
| Solder shorts | √ | |||||||||||||||
| Insufficient solder | √ | |||||||||||||||
| Excess solder | √ | |||||||||||||||
Automated X-Ray Inspection（AXI）
AXI is used to test complex circuit boards that incorporate components with array-style or fine pitch packaging, such as BGAs, CGAs (Column Grid Arrays), CSPs (Chip Size Package), and so on. AXI is often installed during the assembly process, just following the last soldering, whether wave soldering or reflow soldering. Furthermore, AXI is frequently used in conjunction with boundary scan tests, ICT, and functional tests to achieve the best inspection results.
What defects AXI can distinguish:
| Defect Type | AXI | |||||||||||||||
| Components | Lifted lead | √ | ||||||||||||||
| Missing components | √ | |||||||||||||||
| Misaligned/Misplaced components | √ | |||||||||||||||
| Soldering | Open circuits | √ | ||||||||||||||
| Solder bridges | √ | |||||||||||||||
| Solder shorts | √ | |||||||||||||||
| Insufficient solder | √ | |||||||||||||||
| Solder void | √ | |||||||||||||||
| Solder quality | √ | |||||||||||||||
| Excess solder | √ | |||||||||||||||
| BGA and CSP | BGA Shorts | √ | ||||||||||||||
| BGA open circuit connections | √ | |||||||||||||||
Functional Test (FCT)
For Functional test, we just need customers provide us the testing instructions and testing software, then we will design the testing fixtures, programme the chips and test the boards as instructed. In such ways, all boards quality can be guaranteed before delivery.
After IC programming, AOI, and X-ray inspection, printed circuit board assemblies (PCBAs) need to be tested for functionality. You can be sure that the PCBAs will perform as expected in the field because Yingstar, a contract manufacturer with expertise in turnkey PCB assembly, adds value to your assembly projects by offering functional testing (FCT) services. The most thorough test to identify the final pass/fail status of your board after production is PCBA functional testing.
Functional Testing Applications :
●Opens & Shorts
●Display Test
●Power Supply
●Digital Sections
●Analog Sections
●Mixed Signals
●Interface / Communication Test (Calling, Bluetooth…)
●Boundary Scan Test
●Calibration
FCT is accomplished by attaching a wire to your PCB’s on-board connections and using test probes to contact test locations on your board as needed. The testing software for the board is designed to run tests in accordance with the unique requirements of the board’s function. The functional test’s purpose is to examine the entire PCB assembly and its functionality to evaluate whether or not it was produced in accordance with your specifications. This demands a dependable EMS provider who understands how to efficiently work with your PCB assembly for testing.
How to Carry Out Functional Testing ?
The final phase in the PCB assembly process is functional testing. A functional test simulates the operational environment to check that the PCBA functions properly. A device that communicates with the PCBA DUT may be included in the operational environment. Typically, the DUT’s power supply and software test program will load the parameters required for the DUT to function properly.
Functional testing helps ensure that your PC board assembly works properly. It will accomplish this by applying a variety of different signals and currents to stimulate the board’s behavior using testing software designed specifically for the board, and then measuring how the PCBA reacts. It will detect distortions, erroneous currents, and signal timing faults in both analog and digital signals.
A succession of signals and power supply voltages may be applied to the printed circuit board assembly (PCBA). To ensure proper functionality, responses are checked at key points. All testing is carried out in accordance with the specifications and procedures established by the customer’s test engineer.
Chip Programming
And chip programming will be performed before the chips are mounted on the board. We support various package types including:
| DIP, SDIP | QSOP, SSOP | ||||
| TSSOP, PLCC | QFN, MLP | ||||
| BGA, CSP | SOT | ||||
| SOP, MSOP | TSOP | ||||
| QFP, MLF | DFN | ||||
