Long-Term Thermal Reliability of PCB Materials


Reading time ( words)

Abstract

This paper describes the purpose, methodology, and results to date of thermal endurance testing performed at Amphenol Printed Circuit Board Technology in Nashua, NH. The intent of this thermal aging testing is to establish longterm reliability data for PWB materials for use in applications that require 20+ years (100,000+ hours) of operational life under different thermal conditions.

Underwriters Laboratory (UL) testing only addresses unclad laminate (resin and glass) and not a fabricated PWB that undergoes many processing steps, includes copper and plated through holes, and has a complex mechanical structure. UL testing is based on a 5000 hour expected operation life of the electronic product. Therefore, there is a need to determine the dielectric breakdown/degradation of the composite PCB material and mechanical structure over time and temperature for mission critical applications.

Thermal aging testing consisted of three phases.

  • Phase I: 500-hour pre-screen at four fixed temperatures following IEEE98 A.1 and UL746B 20A (completed)
  • Phase II: Short-term aging for 1000 hours at four revised fixed temperatures. Plated through-hole reliability testing using IST and HATS was also completed
  • Phase III: Long-term aging for 25,000 hours at five revised fixed temperatures

This paper will discuss results of this testing to date.

Introduction

The objective of this testing is to establish the electrical strength-temperature Arrhenius curve (temperature life curve) for materials used in PWB for applications that exceed the typical 5,000 hour end of life test defined in UL Standard UL746B. The test methodology presented in this report generates data representing 25,000 hours of operational life.

Read the full article here.

 

Editor's Note: This article originally appeared in the April 2016 issue of The PCB Magazine.

Share

Print


Suggested Items

The ICT 2019 Christmas Seminar

12/16/2019 | Pete Starkey, I-Connect007
Since 2016, the Institute of Circuit Technology (ICT) has held its northern area Christmas seminar at the Majestic Hotel in Harrogate—the elegant and historic English spa town in North Yorkshire. Pete Starkey provides an overview of this popular ICT event.

Calumet Electronics and Averatek Team Up on A-SAP

12/02/2019 | Nolan Johnson, PCB007
Nolan Johnson talks with Brian Hess of Calumet Electronics and Mike Vinson of Averatek about the new, insertable additive processes that the companies are working on together to help factories running primarily subtractive processes to quickly convert to very high-density interconnect (HDI) features, including trace and space from 2.5-mil line and space to 1-mil line and space and below.

Decreasing Bend Radius and Improving Reliability- Part II

11/22/2019 | Kelsey Smith, All Flex
Many of the issues that arise when using a flex circuit come from a lack of knowledge about how to properly design one, especially when the circuit is required to bend. Many novices will design a circuit that calls for bending the flex in too tight of a bend radius, which can cause damage to the circuit and lower the reliability of the end product. This series of articles will focus on the seven key aspects to consider when designing for maximum durability and maximum “flexibility.”



Copyright © 2020 I-Connect007. All rights reserved.