Pretesting for the Best Laminate

Posted Nov 9th, 2020

At TFE, we are always searching for ways to make sure we are providing you, our customers, with the very best and most reliable products on the market today. This is why we are proud to introduce the implementation of our 100 percent high voltage, dielectric pretest on all IMS laminates we offer. This pretest will serve as assurance to you, our customers that you are getting the specified dielectric strength that you need, before you start investing your time and money building your PCBs. This is just another way that TFE is there for you.

Pretesting All IMS Laminates

Aismalibar has implemented a 100 percent high voltage, dielectric pretest on all IMS laminates produced. The 1-3 KV high pot test ensures the specified dielectric strength of the thin material. This pretest is the only way to ensure the dialectical strength is perfect before you spend expensive production time processing. A small strip of copper along each side of the panel is removed so that small slivers in production cutting are not allowed to arc over and contaminate results. The voltage breakdown tests are performed in accordance with IPC-TM-650 part 2.5, 6.2. Five voltage tests are averaged to ensure proper voltage dielectric strength.

The production line voltage test exposes  the sheets of copper clad material to DC 1000 volts and then increased by 500 volts per minute to 2000 volts, followed by an increase to 3000 volts, with a five second hold time. The thinner the dielectric material, the higher the overall thermal conductance, which therefore, drives the required higher thermal conductivity. However, as the inner dielectric material becomes thinner, there is more reason to ensure dielectric voltage strength by performing 100 percent voltage breakdown tests.

The 100 percent voltage testing has shown excellent lifetime thermal cycling resistance in UL testing exceeding 100,000 operational hours.  The very high 2000 to 3000/mil voltage breakdown rating of IMS material from Aismalibar is far superior to FR4 products, which typically have a much lower 750 volts per mil rating.  The comparative voltage tracking index of Aismalibar IMS material is rated at 600 volts for safety in UL applications.