Thermal Management is the hottest topic in electronics at the moment. Effective control of heat is an increasing concern among today’s electronic device designers and, as products become more compact and powerful the heat generated is more intense. Too much heat can reduce service life and affect reliability so the need to dissipate damaging heat effectively is greater than ever. To address the thermal demands of today’s electronic devices, Techsil provides a complete portfolio of high-performance, user-friendly Thermal Interface Materials (TIMs) to suit a variety of current and future heat control needs.
Air is a poor conductor so manufacturers have developed innovative thermally conductive silicone adhesives that can be robot dispensed to help quickly conduct heat away from the PCB to the heat sink (usually an aluminium case lid) or used as potting to act as a temporary heat store to allow heat to dissipate over time. Any air filled gaps, even microscopic, will inhibit the efficient transfer of heat.
Many electronics design engineers prefer the flexibility of a silicone paste; no two surfaces are completely smooth and therefore often do not mate perfectly which results in the creation of air gaps. The soft paste fills the gaps, eliminating the air on the surface very well. Also it can be robot dispensed in intricate patterns.
Silicones are very versatile and in particular have the advantages of being able to bond to difficult combinations of materials and reliability over a wide temperature range and in difficult environments. Used for potting, their flexibility when cured provides excellent protection to sensitive electronics by absorbing mechanical vibration and thermal shock. Alternatively silicone greases can be used as gap fillers if there is a need to re-work the component at a future date.
Techsil are Authorised Distributors for Momentive who have a comprehensive range of thermal management silicones. A comparison summary of their range of silicone TIMs can be downloaded here: Momentive’s Thermal Management Materials
Techsil’s Latest Thermal Management Solutions
Techsil provides a complete portfolio of high-performance, user-friendly materials to suit a variety of current and future heat control needs. Chemistries include silicones, epoxies, compounds and tapes. Here we highlight some of those products best in range in ascending order of thermal conductivity.
Download: Techsil’s Thermal Management Product Summary
Before choosing a thermally conductive adhesive it is important to consider a number of factors and not just selecting the one with the highest thermal conductivity. E.g.
1. What substrates are you bonding together?
2. What is the size, dimensions and joint design?
3. How strong does the bond need to be?
4. How quickly do you need the adhesive to cure?
5. How will it fit into your production line?
6. What cure mechanism is acceptable in your process?
7. For potting applications – what is the volume of the area to be potted? If large, a slower curing product could be better.
8. How complex is the part? Will the adhesive flow easily around the part leaving no gaps?
Chris Dilley, Sales Director comments, “Application technology is really important because less is always more. The thicker the layer of thermal interface material, the more likely that this will actually limit the rate at which the heat is dissipated. This is because the heat sink itself will have a higher thermal conductivity than the paste, so the aim is to get heat to the heat sink as quickly as possible and this is achieved through thin BLT’s (Bond Line Thickness).
Every application and every surface is different and that is why we like to get involved at the design stage to understand the substrates being used, the heat generated, how to eliminate the air and achieve a good BLT for the client and ultimately this means we can achieve a very efficient heat transfer and good thermal management solution.”
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Tel: 01789 773232
Techsil Ltd
34 Bidavon Industrial Etstae
Waterloo Road
Bidford-on-Avon
Warks
B50 4JN
