Question: What thermal conductivity test method was used to achieve the values given on the data sheets?
Answer: The Anter Quickline 10 was used to run this test. Bergquist has published an application note about the modifications to the ASTM D5470 test method to appropriately test Gap Pad materials at low 10 psi pressure; see Bergquist Application Note #112.
Question: Is Gap Pad offered with an adhesive?
Answer: Currently, Gap Pad VO, Gap Pad VO Soft and Gap Pad VO Ultra Soft are offered with or without an adhesive on the Sil-Pad 800/900 carrier-side of the material. The remaining surface has natural inherent tack. All other Gap Pads have inherent tack.
Question: Is the adhesive repositionable?
Answer: Depending on the surface being applied to, if care is taken, the pad may be repositioned. Special care should be taken when removing the pad from aluminum or anodized surfaces to avoid tearing or delamination..
Question: What is meant by "natural tack"?
Answer: The characteristic of the rubber itself has a natural inherent tack, without the addition of an adhesive. As with adhesive-backed products, the surfaces with natural tack may help in the assembly process to temporarily hold the pad in place while the application is being assembled. Unlike adhesive-backed products, inherent tack does not have a thermal penalty since the rubber itself has the tack. Tack strength varies from one Gap Pad product to the next.
Question: Can Gap Pad with natural tack be repositioned?
Answer: Again, depending on the material that the pad is applied to, in most cases they are repositionable. Again, care should be taken when removing the pad from aluminum or anodized surfaces as to avoid tearing or delaminating the pad. The side with natural tack is always easier to reposition then an adhesive side.
Question: Is Gap Pad reworkable?
Answer: Depending on the application and the pad being used, Gap Pad has been reworked in the past. Bergquist has customers that are currently using the same pad for reassembling their applications after burn-in processes and after fieldwork repairs. However, this is left up to the design engineer’s judgment as to whether or not the Gap Pad will withstand reuse.
Question: Is liquid Gap Filler reworkable?
Answer: It is highly dependent on the application and its surface topography. Liquid Gap Filler will cure with low adhesive strength to the application surfaces.
Question: Will heat make the material softer?
Answer: In the temperature range of -60°C to 200°C, there is no significant variance in hardness for silicone Gap Pads and Gap Fillers.
Question: What is the shelf life of Gap Pad?
Answer: Shelf life for most Gap Pads is one (1) year after date of manufacture. For Gap Pad with adhesive, the shelf life is six (6) months after the date of manufacture. After these dates, inherent tack and adhesive properties should be recharacterized.
Question: What are the upper processing temperature limits for Gap Pad and for how long can Gap Pad be exposed to them?
Answer: Gap Pad VO materials and Gap Pad A3000 are more stable at elevated temperatures. Gap Pad in general can be exposed to temporary processing temperatures of 250°C for five minutes and 300°C for one minute.
Question: Is Gap Pad electrically isolating?
Answer: Yes, all Gap Pad materials are electrically isolating. However, keep in mind that Gap Pad is designed to FILL gaps and is not recommended for applications where high mounting pressure is exerted on the Gap Pad.
Question: How much force will the pad place on my device?
Answer: Refer to the Pressure vs. Deflection charts in Bergquist Application Note #116.
Question: Will Gap Pad and Gap Filler work in my application? What size gaps will Gap Pad and Gap Filler accomodate?
Answer: Gap Pad and Gap Filler can be used wherever air can be replaced, such as between a heat generating device and a heat sink, heat spreader or housing. This can be done by using one sheet of Gap Pad or individual pieces of appropriate thicknesses if stack-up tolerances and height variations are significant.
Question: What is meant by "compliance" and "conformability", and why is this important?
Answer: The better a Gap Pad complies and conforms to a rough or stepped surface, the less interfacial resistance will be present due to air voids and air gaps. This leads to a lower overall thermal resistance of the pad between the two interfacest.
Question: Is anything given off by the material (i.e. extractables, outgassing)?
Answer: Primarily for aerospace applications, outgassing data is available by contacting a Bergquist representative.
Question: What is ISO9001:2000?
Answer: 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 if the system, including processes for continual improvement of the system and the assurance of conformity to customer and regulatory requirementst.