What are the key function tests of PCBA processing? What should be noted during testing?

Date：2021-11-10 15:31:41 Views：1793

There are many links involved in PCBA processing and manufacturing process. We must control the quality of each link to produce good products. Generally, PCBA consists of a series of processes, such as PCB circuit board production, component procurement and inspection, SMT patch processing, plug-in processing, program firing, PCBA testing, aging, assembly and so on, Let's focus on analyzing the related problems of function test:

1、 Functional test plan

DFM instructions are usually provided in the design process before SMT processing of a circuit board. This will keep you in the time planning of "design for testability" throughout the design process. It will clearly state the schematic diagram, PCB layout and even what test aspects are included in the microcontroller code.

All components have the correct voltage, capacitive touch sensors and LEDs are correctly installed, and the microcontroller has been programmed and operated as expected. This plan for functional testing will guide the whole PCBA circuit board processing quality and have a significant guarantee.

2、 Test point

The test point is just a PCB pad on the board, which is specially used for easy detection. For various reasons, I do not want to rely on the pins or pads of the detection assembly. The dimensions of these pads are not specified, but they should be large enough for easy contact with the test probe.

3、 In system programming

If you look at the internal structure of any sufficiently complex product, you may find a programming connector or an empty position on the PCB where the programming connector may be placed. This connector is usually used to program the microcontroller installed on the PCB, so it is called "in system". In the mass production scenario, it is meaningless to install this head. It is used by designers for debugging purposes and is not installed in the production process to eliminate costs.

4、 Test fixture

For early prototypes or a small number of designs, you can manually test each circuit board yourself.

The welding quality of components on PCB board directly affects the performance of products. Therefore, the quality inspection and testing of PCB board is a necessary link for the quality control of PCB manufacturers.Pay attention to the following points when testing PCB:

1. Insulation performance of electric soldering iron: do not use live soldering iron for welding, and confirm that the soldering iron is not live.

2. Do not cause short circuit between pins: when measuring voltage or testing waveform with oscilloscope probe, do not cause short circuit between IC pins due to sliding of lead or probe.

3. Attention should be paid to the heat dissipation of power integrated circuits: do not work when the radiator is at high power.

4. Reasonable detection of PCB lead: if it is necessary to add peripheral components to replace the damaged parts inside the integrated circuit, small components shall be selected, and the wiring shall be reasonable to avoid unnecessary parasitic coupling.

5. Ensure welding quality: carefully check the welded integrated circuit, confirm that there is no solder adhesion, and turn on the power supply.

The above is the related content of "PCBA processing function test" brought by the core creation test. I hope it will be helpful to you. We will bring more wonderful content in the later stage. Our testing services include: electronic component testing and verification, IC true and false identification, product design and material selection, failure analysis, function testing, factory incoming material inspection, tape braiding and other testing items. Warmly welcome to call, we will serve you wholeheartedly.