Surface Insulation Resistance (SIR) Testing

Measure the reliability of your printed circuit boards under real-world temperature and humidity conditions with surface insulation resistance (SIR) testing from Element.

Surface insulation resistance (SIR) testing, also referred to as temperature humidity bias (THB) testing, is a test process used to determine if a printed circuit board is likely to fail when exposed to various temperature and humidity conditions.

As PCBs become smaller and the spacing between their conductive parts decreases, they become more susceptible to failure modes caused by surface residues and humidity. Element’s testing experts give you detailed insight into how your product behaves under these environmental conditions, helping you design superior, more reliable PCBs.

Why SIR testing is necessary

With the electronics industry continuously demanding smaller, lighter parts that are still able to endure extreme conditions, the engineering challenges associated with delivering reliable PCBs are significant. As new assembly methods, product designs, and product chemistries are introduced, it is especially critical to understand what conditions may cause them to fail.

The most common failure modes for PCBs are caused by a combination of conductive residues left on boards after the assembly process and surface humidity. These conditions cause corrosion that can affect the long-term reliability of the assembly. Surface insulation resistance testing checks a PCB’s resistance to common failure modes like conductive anodic filament (CAF) formation or electrochemical migration and validates and records the effects of new processes on the product’s surface insulation resistance.

How SIR testing is performed

Our experts can help you select the most appropriate SIR testing process for your product, as different methodologies will apply based on the product and its intended use. In general, SIR testing classifies, qualifies, or compares soldering fluxes and/or cleaning processes. The testing process applies differing temperatures and humidities in a controlled setting to mobilize any surface contaminants and accelerate any failures that might happen while the product is in use.

Our experts evaluate the product’s electrical attributes during or after this accelerated environmental exposure to gain a complete picture of the product’s performance under these severe conditions.

Why choose Element?

Element’s testing experts are up to date on the latest SIR testing standards and methodologies and can give you the most complete picture of your product’s performance with the industry’s most advanced testing. We take a hands-on approach to ensuring that you not only get the answers you need, but can accurately interpret and act upon your test results.

We help you qualify and verify new processes or changes in your existing processes and ultimately deliver the best possible product to market.

For a complete list of our capabilities and accreditations, or to speak with one of our testing experts, contact us today.