EMI and RFI shielding of electronic devices can be critical to their reliability and safety. Proper protection and shielding are vital in many challenging industries including aerospace, medical devices, and transportation. In addition to shielding, grounding of devices as well as protection from galvanic corrosion can extend service life and reliability. Chase Corporation has developed a unique line of preformed gasketing and shielding materials that can combine to serve the multiple functions of shielding, grounding, and corrosion resistance within a single material.
image: Plastic transitioning from solid to amorphous
One of the most common terms that you hear when discussing polymers used as adhesives and coatings is the “glass transition temperature” (often abbreviated Tg). This property is in fact one of the most critical to consider when choosing the correct material for your application. Since many of us never got further than high school physics and chemistry, this term can be a little confusing and deserves explanation.
A layman’s definition of the glass transition temperature of a polymer is the temperature at which an amorphous polymer moves from a hard or glassy state to a softer, often rubbery or viscous state.
The past few decades have seen the emergence and use of ultraviolet (UV) light cured polymers across a range of industries and applications. UV cured polymers have proven their value in applications such as printing inks, adhesives, and protective coatings among others.
One of the first industries to accept and utilize UV curing polymers was the printing industry. Existing technology was mainly polymers and inks dissolved or suspended in highly flammable and hazardous solvents such as Toluene and Xylene. UV curable inks and coatings were ideally suited for this industry. Their nearly immediate curing allowed for high speeds, and their 100% solids composition often eliminated the need for pollution and fire control technology.
Millimeter-wave (mmWave) radar technology has emerged as an accurate and cost-effective approach to motion sensing and control. Resin Designs’ TechFilm B-Stage Epoxies (electrically conductive and structural) have been enhancing the performance of these devices. With their precise bond line thickness and placement accuracy, the B-stage epoxy films play critical roll in ground plane formation and adhesion of patch antenna to power boards. The technology has been front and center in the automotive arena from basic safety innovations like back up and side sensing devices to full autonomous driving development. As mmWave devices increase in number within an automobile, a number of key factors are driving development including:
Cationic and free radical are the two most popular mechanisms for UV adhesives. Approximately 93% of the UV market is in free-radical chemistry while cationic has about 7%. Although a minority of the market, cationic adhesives provide strategic advantages over traditional free-radical acrylate chemistries. These advantages are detailed below.
B-stage epoxy films for clean reliable bonding/thermal and electrical conductivity
Most of us are familiar with epoxy adhesives and coatings, especially those of us within the electronics and medical device industries. We have all seen and often used two-component liquid epoxies. They are provided in syringes or pails for dispensing as adhesives, sealants, gaskets, and coatings. There is, however, a lesser known relative that can be cleaner, more consistent, environmentally friendly, and capable of unique properties such as thermal and electrical conductivity. It is known as B-stage epoxy film.