ThermoSink 35-1 Potting Gel

Resin Designs has released a new silicone potting gel that has exceptional thermal conductivity. ThermoSink 35-1 is a two part silicone that cures at room temperature to a flexible Shore A hardness of 50. With a thermal conductivity of 3.4 W/mK, it is well suited for potting power supplies, transformers, inverters, and many other electronic devices generating heat that needs to be removed. Dielectric properties are also excellent, making it a superb choice for high voltage applications. Specific values can be found on the data sheet. Finally, it has a UL 94 flammability rating of V-0.

ThermoSink 35-1 combines high thermal conductivity with premium dielectric properties in a protective, soft solid that sets a new standard for potting materials. Already used in automotive applications we believe it is applicable in other markets such as electric power, telecommunications infrastructure, aerospace, military, and so forth. Click
here for more information and to request a sample or quote.

PINK Plasma Representation

We are very pleased to announce that Assembly Answers now represents PINK GmbH Thermosysteme providing sales and support for plasma systems. With engineering and manufacturing in Germany, PINK is looking to expand its business in North America. Reaction has already been very favorable, with high accolades from customers familiar with more established brands in the US.

PINK plasma systems are ideal for cleaning organic residues from surfaces prior to bonding or coating. Even surfaces that have been previously cleaned with wet processes can still retain contaminants that might interfere with adhesion of subsequent coatings. With a PINK plasma treatment they can be removed, leaving an ultrapure surface. As a dry process, there is no drying or waste disposal required.

A major area of application for PINK Plasma Systems is surface activation, especially for plastics. Many plastics are nonpolar and therefore don’t wet well. By activating the surface with polar groups, wetting is substantially enhanced, allowing for good adhesion with adhesives or coatings. PINK Plasma Systems are distinctive for activating plastics with very little temperature rise, thus preventing distortion of the plastic body.

PINK plasma systems are powered with microwave energy (2.45 GHz) as opposed to the more common RF and microwave frequencies. Efficient, clean. and safe for your product, PINK Plasma Systems are perfect for creating ultra-clean / ultra-active surfaces that will bond or coat well. The tabletop model V6-G is shown below. Larger cabinet and custom systems are available as well. Click
here for further information.

PiNK Plasma V6 benchtop system

Adhesive Dispensing: Human vs. Robot

The keys to dispensing any adhesive are volume and placement control. Thin coating on a large area? Think of painting with a brush, roller, or sprayer. Putting down long traces thick or thin? Use a syringe or cartridge with an air pressure valve. Small dots? Then a syringe with precision dispenser is called for. All of these applications can be done by hand, usually with skilled technicians and in some cases with the aid of a microscope. But wouldn’t it be easier to let a robot do it? Teach it once with a simple set of instructions and it will do the repetitive, difficult work for you, with much greater accuracy. Even a one-time task can be easier by inputting a program than doing it manually. I liken it to ripping a long board with a circular saw. You can scribe a line and follow it manually (more or less). Or you can set up a fence and push the saw along it. It takes a little more work up front to set up, but the result is a straight, clean cut that is ultimately more satisfying.

Our desktop robots are not the cheapest available. They are also not the most expensive. They are robust machines that fit comfortably in both low and high volume environments, from one-off R&D projects to full-on production. We have extensive dispensing experience and will customize a system for your specific needs. Go to our
Robot Systems page for more information and to see a video of a more advanced system in operation. You may not need this much capability, but rest assured we can provide it if you do.

Choosing Epoxy Film For Cost Reduction

Selection of an adhesive can take many paths and every application has unique constraints. We have provided a technical checklist for adhesive selection, but ultimately cost is a big factor. The fact is that film format epoxy is more expensive than a liquid format on a volume or weight basis. This is very simply due to the higher level of processing necessary to make a filmed product. But does that mean all users of epoxy film are automatically producing a more costly product? The answer is clearly no, but the question is why?

After reviewing numerous applications across many industries, the standout cost driver for epoxy film is first pass yield in production. Yield improvement of just a few points can reduce cost significantly. For example, moving from 90% to 95% yield means the effective cost of goods drops 5.3%. Considering that adhesives typically represent a very small fraction of the material budget for most products, a moderate increase in adhesive cost could lead to significant savings overall. Many processes using film adhesives approach 100% first pass yield. Some of the reasons for improvement are:
  • Reproducible bond line thickness
  • Reproducible amount of adhesive deposited
  • Elimination of rework due to insufficient or excessive adhesive
  • High strength bond
  • Reduced functional tuneup time of device (most notably in microwave applications)

If an assembly process is currently running 90% or better yield, there may be an opportunity for cost improvement that justifies looking at alternative adhesives. Any process running less than 90% probably justifies a critical assessment.

Yes, epoxy film adhesives are more expensive than liquid epoxies. Yet in considering the total production process, they can in fact contribute to the lowest cost solution.
Click here to review the many options available.

Delivering Unique Epoxy Film Structures

Sometimes an adhesive interface needs to be more than just a mechanical bond. Sometimes it needs to be electrically conductive, or conversely, electrically insulating. Sometimes it needs to be thermally conductive, or again conversely, thermally insulating. But there are also applications that require specific structures for assembly or design reasons. For example, to set a specific gap in a bond line the use of a carrier film such as DuPont™ Kapton® polyimide or Mylar® polyester coated with b-stage epoxy on both sides is very effective. Coating the epoxy on just one side produces an overlay adhesive that is readily cut and easily processed in an automated line. Both of these carrier materials also offer excellent dielectric and chemical barrier properties. For a high breakdown voltage, it’s hard to beat an epoxy-Kapton-epoxy bond line.

Resin Designs has the flexibility to coat any of their
B-stage epoxies on these carriers, either one side or both sides. With a distinctive set of resin systems, a wide variety of fillers, and multiple carriers, Resin Designs can produce a broad selection of b-stage epoxy products. What application do you have that might benefit from a unique structure?
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