PCBA function test guide

pcba Functional testing, which is performed to ensure that the product meets the design requirements both in terms of product description, user plans and operating programs, is performed according to the characteristics of the product description, user plans and operating programs. Functional testing ensures that the program works properly, tests the software against functional requirements, and tests all features and functions of the system to ensure that it meets the requirements and specifications.

Functional testing is also known as black box testing or data driven testing because only the various functions need to be tested one by one from the software product interface, the test case architecture based on written requirements, and the evaluation of the input data between the expected results and the actual results one by one, not the internal structure and code of the software.

PCBA functional testing will cover both hardware and software. The customer must send the test plan to the manufacturer to guide the test engineers. You need to list the behaviors and results (e.g., if you press, for example, button one, the green light comes on).

Why need Functional Testing

The purpose of PCBA functional testing is to ensure the quality of the product, improve the product qualification rate, improve the production process and get a better user experience. Functional testing can gain these following benefits:

·By simulating the operating environment for the PCB assembly under test, functional testing minimizes the cost for the customer. It is not necessary to provide the real and expensive testing equipment.

·It helps to avoid expensive system tests that often save the customer time and financial resources.

·It is possible to test 50-100% of the product before shipping, thereby minimizing the customer’s time and effort to test and debug the PCB assembly.

·It is possible for skilled professionals to extract the maximum productivity with a functional test, making this the most effective testing apart from a full system test.

·Along with ICT and flying probe tests, functional testing can make the PCB assembly error free and more robust.

PCBA function test method

1. Manual Test Fixture

Manual test fixtures use baking paint and acrylic pinboard output PCB input/output and power supply, and manually simulate input/output. The results are confirmed by the tester.

Due to high labor costs and low efficiency, manual testing is gradually replaced by manual test fixtures, which are only part of the test, but less demanding and less costly for manual participation.

2.MCU control function test

Make the fixture lock or pneumatic fixture and pull out the probe. Then connect the input/output power supply to the microcontroller circuit so that the microcontroller can run the test program and automatically measure the analog input/output.

This method is characterized by moderate price, high test efficiency, guaranteed test quality and less human intervention. However, this method lacks versatility is generally only applicable to machines equipped with fixtures.

3.PCBA Universal Automated Test System

PCBA universal automated test system designed for most manual testing and design. Because the test system is powerful, you can test a variety of PCBA and become a universal test system.

Humanized test principle: By sampling the model parameters, setting the error range, and comparing with the test board to determine whether it is qualified or not.

Simplicity test: Press the needle bar manually and the system automatically handles it. Product quality can be judged by the system, excluding the influence of human judgment factors. Moreover, its speed is incomparable to manual testing.

The system consists of acquisition, control board and test software. It is connected to a programmable AC/DC power supply and DC load. High sample rate products can be equipped with an external oscilloscope.

The system can test PCBA synchronization signals, user interfaces, modular programming environment models and conversions.

This method is costly, but testing is fast and requires no human intervention. It is versatile in its application and provides more comprehensive testing.

PCBA function test content

PCBA function test content voltage, current, power, power factor, frequency, duty cycle, position determination and other functional parameters of the measurement.PCBA function test contains content: general part:

1: The power supply part of the test–whether the power supply is working properly, test the voltage of each point–use a comparator or other.

2: Port (interface) test, whether there is Short & Open, resulting in abnormalities.

3: Integrated circuit module IC I/O read/write function test – Flash & EEPROM & CPU & SDRAM & logic IC etc.

4: Special function tests (different board requirements are inconsistent) – such as infrared, the need for external receivers.


At LSTPCB, we provide customers with complete PCB testing solutions and test all products. We have experience testing a wide range of PCBA products and can quickly provide test solutions to our customers to help them find the best test methods to improve performance, quality, manufacturability, reliability and reduce costs.