Panacol has developed a new range of high-performance adhesives for frame-and-fill applications on printed circuit boards. Such processes are used to protect highly complex or sensitive areas on printed circuit boards. In the first step, a frame is applied with a high-viscosity adhesive. In the next step, this area is filled with a low-viscosity filler material. In this way, areas on the PCB can be protected from mechanical influences.
The combination of frame-and-fill materials enables the application of minimal barrier and potting heights and cures to form a homogeneous coating. In Panacol's new frame-and-fill adhesive range, the components are coordinated in such a way that frame and fill can be optimally dispensed wet-on-wet without the adhesives, which are still liquid, causing unwanted running on the PCB.
The frame material Structalit 5704 is a black, thermally curable, one-component epoxy resin adhesive. This frame and glob top material has excellent bead stability and a high glass transition temperature of 150 °C to 190 °C, depending on the curing parameters and layer thicknesses produced. Due to its very low ion content of less than 20 ppm, the frame material can also be used without hesitation for chip encapsulation on printed circuit boards.
Panacol has developed a range of adhesives with different rheological properties as fill materials. The adhesives Structalit 5717 to Structalit 5721 have optimized flow properties so that they can be used on various chip and bond wire geometries due to the different viscosities. As the fills are based on the same chemistry as the frame material, they also offer the same physical and chemical properties of high glass transition range, ion purity, temperature stability and minimal shrinkage behavior.
When cured, the frame and matching fill form a black, opaque and scratch-resistant coating with a temperature stability of up to 200 °C.
