Master PCB Testing: Essential Methods Explained

Sep 20,2019

Testing is an important aspect of the manufacturing process as it detects defects and helps fix them before the product goes out into the market. This holds true for any product from a plastic toy to a PCB. Printed circuit boards or PCBs are an integral part of most electronic and electromechanical devices nowadays, and they are becoming increasingly complex owing to advanced functionalities and reduced sizes of devices. Hence, testing of PCBs in terms of functionality and mounting of parts is extremely crucial. There are various types of testing methods used for testing of PCBs. This post discusses the importance of PCB testing and various types of testing methods.

Why PCB Testing is Necessary?

PCBs are embedded in umpteen electronic devices, and their functioning largely depends on the functionality of PCBs. It is essential to test the PCBs in design stages and the later stages of production because there is a lot of cost and time involved. If the PCBs are faulty, it will negatively impact the business of the product it is embedded in. Also, error-free products increase the brand credibility in the market.

Tools and Devices Used to Check PCBs

So, PCB tests are necessary as electronic products may become dysfunctional any time, if PCBs fail to perform. There are various tools and techniques to conduct these tests.

• Signal and power integrity tests are used to fix design issues in PCBs. These are PCB design analysis techniques. Test points of the board are checked with the help of certain PCB fixtures, which are electromechanical devices; nowadays they are intelligent as well.

• There is automated test equipment to check the issues related to ICs and system-on-chip.

• To check and fix various parameters such as performance, capacity, soldering issues, tolerance levels of impedance, and so on, there are testing methods mentioned below.

A Discussion on Various Types of PCB Testing Methods

Various types of PCB testing methods are implemented to check the PCBs in terms of several factors through almost all the stages of production. Here are some of them:

• Functional testing:

  This is done in the final stage of manufacturing, which gives a go-ahead to the product if there are no issues, else the product is rejected. So, in this stage, the entire product as a whole is checked, and not individual parameters such as soldering, board, tolerance, and so on. Hence, the code for functional testing is really complex and needs to cover a whole lot of points which may be arranged differently in each PCB. The hardware part for functional testing includes functional testers, power supplies, loads, and probes.

• In-circuit testing:

  This method involves the testing of all the components on a PCB. It can identify defective components and replace them. The integrated circuits (ICs) are checked using certain probes. This test checks for open and short circuits, as well as component values.

• Bare board testing:

  A bare board as the term implies is a plain board without any layers and mountings. Circuit connections are checked on this fabricated board by applying low voltage at specific points. This is done to identify and fix open and short circuits.

• Assembly level testing:

  Functionality of the PCBs after the assembly is checked in this test. This may be manual or automated optical inspection (AOI).

Are you looking for new PCBs or PCB assembly for your application? If yes, ensure you source them from a reputed manufacturer and supplier who uses in-circuit testing, functional testing, and other testing methods covered in this post. Creative-Hi-Tech Ltd. is a known provider of custom PCBs and assemblies, based in Illinois. With a market presence of more than 20 years, the company caters to complex PCB assembly requirements of various industries such as military, medical, aerospace, and industrial electronics.