silicone press pad
I hope at this point most of our customers at least somewhat think of NEDC when they think of their PCB. We make thermal pads, adhesive preforms, and RF absorbers. However, maybe they don’t think about us when they think of press pads. When PCB laminations are used to manufacture printed circuit boards the pressure is almost never even. For that reason, manufacturing engineers utilize press pads to distribute the pressure evenly across the laminated surface of the PCB.
Reasons for Using Silicone Press Pads/Heat Press Pads
NEDC has waterjet cutting capability, and die-cutting capabilities. With those machines, we typically cut press-pads into custom circuit board shapes. We have seen some interesting combinations of conventional gasketing materials coupled with reinforcements to design PCB press pads. We see kraft papers, we see unsupported silicone sponge with a laminated fiberglass surface, and many others. However, in this blog post we decided to talk about some of the commonly used materials for press pads. Typically, we see silicone-based products used for press pad applications – this is for a few reasons:
- They are non-stick. When lamination occurs in the heat press, adhesive is flowing. If adhesive gets onto the pad, you want a pad that can easily pull away from the substrate, or the adhesive itself.
- They have high temperature resistance. Silicone rubber has a high temperature range.
- They typically have a smooth topology.
- For the above reasons, they are almost always reusable for multiple laminations.
Why is Fiberglass needed in Heat Press Pads?
Fiberglass is used in Heat Press Pads to ensure the integrity of the pad after being crushed, and ensuring it does not extrude out during the heat press/laminating process. The fiberglass coupled with silicone helps the pad maintain its dimensional stability during multiple layups processes.
Availability of Silicone Press Pads
In addition, most press pads have some sort of reinforcing material such as fiberglass. The fiberglass reinforcement is to prevent extrusion of the press pad due to the immense pressure of the lamination process.
Saint Gobain Performance Plastics has a few different configurations of silicone rubber materials that are commonly used for press pads.
Rogers Corproation also sells a heat press pad that we have highlighted below.
Product/Type of Product/Reinforcement/Specifications – thicknesses available for press pads
Norseal R10450/Closed Cell Silicone Sponge/Fiberglass/n/a – .063’’, .125’’, .188’’
Norseal 3320/Solid Silicone Rubber/Fiberglass/AMS-3320 – .063’’, .094’’, .125’’
Norseal 4420/Solid Silicone Rubber/Fiberglass/n/a -.045’’, .063’’
Norseal 4444/Solid Silicone Rubber/Fiberglass/n/a – .063’’, .094’’, .125’’
Norseal 4480/Solid Silicone Rubber/Fiberglass/n/a – .063’’
Rogers HT-1500/Solid Silicone Rubber/Fiberglass .016”-0.063”
More Information on Press Pads/Heat Press Pads
At NEDC we also offer lamination services to press pad materials with different tape adhesives such as acrylic or silicone. For more information on different materials offered for PCB Press Pads, or please contact sales@nedc.com.