Thermal Interface Selection Guide - Bergquist Company - #47

Sil-Pad A2000 utilizes a different filler package than Sil-Pad 2000. A: This change results in a more compliant Sil-Pad A2000 material that inherently lowers interfacial resistance losses.This reduction in interfacial resistance results in improved overall thermal performance when measured at lower pressures in standard ASTM D5470 and TO-220 testing.

The answer is based on the assumption that the primary design

intent is to increase thermal performance. If your application Q:

utilizes lower clamping pressures (e.g. 10 to 75 psi) you will find

the Sil-Pad A2000 to provide excellent thermal performance. In A:

contrast, if you are designing for higher clamping pressures (e.g.

100 psi or greater), it is likely that you will require the thermal

performance characteristics of the Sil-Pad 2000.

Yes. Bergquist evaluates and publishes voltage breakdown, Q:

dielectric constant and volume resistivity data per ASTM

standards for these materials. Due to differences between

ASTM lab testing and actual application performance, for best A:

results, these characteristics should be evaluated within the

actual customer system.

Yes. With the new environmentally "green" process improvements added with the introduction of Sil-Pad A2000 products, the A:

materials are now available in roll form.The original Sil-Pad 2000 material cannot be produced in continuous roll form.

Sil-Pad 800 is specifically formulated to provide excellent thermal performance for discrete semiconductor applications that utilize Q: low clamping pressures (e.g. spring clips at 10 to 50 psi). In con- A: trast, if you are designing for higher clamping pressure applications using discrete semi-conductors (e.g. 50 to 100 psi), it is likely that you will prefer the combination of high thermal performance and cut-through resistance inherent in Sil-Pad 900S material.

Sil-Pad 980 is specifically formulated to provide superior cut-through and crush resistance in combination with excellent heat transfer and dielectric properties. Sil-Pad 980 has a proven history of reliability in high-pressure applications where surface imperfections such as burrs and dents are inherently common. These applications often include heavily machined metal surfaces manufactured from extrusions or castings. Sil-Pad 900S carries a high level of crush resistance and is more likely to be used in burr-free or controlled-surface finish applications.

Sil-Pad I500ST and Sil-Pad II00ST have an inherent tack on both sides of the material.This inherent tack is used instead of an adhesive.The tack provides sufficient adhesive for dispensing from the carrier liner and placement on the component. Sil-Pad I500ST and Sil-Pad II00ST can be repositioned after the initial placement.

Sil-Pad I500ST and Sil-Pad II00ST wet-out the application surfaces at a very low pressures. Optimal thermal performance is achieved at pressures as low as 50 psi.

Each application has specific characteristics (e.g. surface finish, flatness tolerances, high pressure requirements, potential burrs, etc.) that determine which Sil-Pad will optimize thermal performance. Select a minimum of two pads that best fit the application, then conduct testing to determine which material performs the best.

The ISO certification is the adoption of a quality management system that is a strategic decision of the organization.This International Standard specifies requirements for a quality management system where an organization: a) needs to demonstrate its ability to consistently provide product that meets customer and applicable regulatory requirements, and b) aims to enhance customer satisfaction through the effective application of the system, including processes for continual improvement of the system and the assurance of conformity to customer and regulatory requirements.

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