Circuit card burn-in

This is a contributed article, for November 2022. Thanks to Ken!

What is Burn-in Testing, and its importance in PCB Assembly

The reliability of a PCB is crucial to the reliability of an electronic product. Particularly when PCBs are being deployed in mission-critical equipment, their failure can have dire consequences. It is, therefore, imperative that PCB manufacturers take the utmost care in their PCB fabrication process ensuring that the PCBs live up to the highest quality standards. This involves conducting a whole series of tests. Among those tests, burn-in testing remains very important. Let us take a closer look at what exactly is Burn-in testing & what is its importance.

What is Burn-in Testing?

Simply put, Burn-in testing helps manufacturers figure out if the board can handle excessive heat. During this testing, the technicians run a current through the board while there is a high-temperature environment. Typically this is done for between 48 & 168 hours. Post this, the board’s functionality is tested. This offers the manufacturer the time & the space to correct any defects and to see whether any components failed.

What Does Burn-In Testing Do?

Essentially with Burn-in testing, the manufacturer conducts a simulation of what the circuit board would need to go through, should there be extended use. Burn-in testing is therefore often also referred to as Accelerated Lifetime Tests.

You can compare Burn-In testing to crash testing that is undertaken on vehicles. With burn-in testing, the PCBs likelihood to break down, especially in its early period of use, is determined. Needless to say that with issues identified early, costly errors can be avoided.

Advantages of Burn-In Testing

The biggest benefit that Burn-in testing offers, of course, is that it ensures that any errors are detected early & therefore the boards do not break down. In fact, electronics are known to have a high failure rate at the beginning of their life cycle. With Burn-In testing instances of infant mortality failure are significantly reduced.

Other than that also, it offers a number of benefits. Let us look at some of them below:

  • Ensures repairs are cost-effective & easy- A corollary of detecting a defect early is that the manufacturer can fix the issue easily.
  • Ensures the board meets customer needs- It makes sure that the boards are designed as per the needs of the product & their potential use.
  • Cuts down on returns & replacement costs- It stands to reason that with the board designed in a manner that chances of failure are minimized, it cuts down on return & replacement costs.
  • Helps in component testing- It helps to test any potential issues in components early so that components that aren’t operating at optimal capacity are replaced early on.

Types of Burn-In Testing

There are primarily two types of burn-in tests:

  • Static Burn-In Testing
  • Dynamic Burn-In Testing

Static Burn-In Testing

Static testing tests the board against a single criterion.  It, therefore, is quicker as also extremely cost-effective. What static testing entails is running probes from component to component in a temperature-controlled environment.

With this test, you can determine what constant exposure to extreme temperatures can do to the board. For boards that have to perform in high-temperature environments, for example, this kind of testing is ideal. Since each component is tested, it is easy to replace components that show an error.

Dynamic Burn-In Testing

This involves setting up a testing chamber. What is done here is that the chamber is set at a particular temperature & then current is run through every component. The difference here is that components run input signals into every element. With this testing the following objectives are attained:


  • The components are tested against voltage
  • They are also tested for temperature resistance

For boards that need to operate in harsh environmental conditions, this testing works best. It ensures that any malfunctioning components are identified early & replaced.

It is prudent to carry out burn-in testing several times to ensure that you are fully protected after PCB manufacturing. Of course, besides burn-in testing a professional manufacturer will also carry out a bunch of other tests including but not limited to:

  • X-Ray
  • AOI
  • Flying probe
  • Functional testing
  • In-circuit testing

ith the above testing, the number of defective products that hit the market can be significantly reduced. Also, the average lifetime of the product is known to increase significantly.

Author Bio:

Ken Ghadia works as Sales Engineer at Technotronix. He brings 15 years of experience in Printed Circuit Board sales and technical client service. Feel free to get in touch with him on Twitter.