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BISCO(TM) Silicone press pads reduce downtime in the lamination of multi-layer boards
BISCOTM Silicone press pads reduce downtime in the lamination of multi-layer boards
Keywords Rogers, Lamination
Rogers Corporation has introduced BISCO™ Silicone press pads used in the lamination of multilayer printed circuit boards (PCBs), flexible circuits and liquid crystal display modules (Plate 2).
"Pads made from BISCO™ Silicone materials offer 25 to 100 times longer life than traditional pads made from sheets of brown Kraft paper", said Susan Baushke, BISCO™ Silicone's product manager.
Plate 2 Rogers Corporation has introduced BISCO TM Solid Silicone press pads for PCB lamination operations
"Not only is the product cost effective, it saves time at the press", added John L. Daniels, Rogers' director of Asian Sales. "The ability to reuse a pad means there is one less variable an operator must deal with in the lamination process", Daniels said. He noted that the use of silicone press pads is fairly common in Asia.
BISCO™ Silicone press pads consist of a reinforcement layer made of Fiberglas cloth that is encased between two layers of calendered silicone rubber. Standard thickness is 1/16" (1.6 mm) and the material is supplied in widths up to 36" (91.4 cm). Rogers offers two grades:
BISCO™ HT-1500 Solid Silicone. A general-purpose material, HT-1500 can be used at temperatures of 300-350°F and pressures of 250-400 psi. With a durometer of 75, each pad lasts 25 cycles on average.
BISCO™ HT-1510 Solid Silicone. A high-performance material, HT-1510 can be used at temperatures up to 550°F and pressures of 250-400 psi. These pads, which have a durometer of 80, last approximately 100 cycles each.
At the beginning of the lamination process, an operator positions press pads against the top and bottom platens of the press. The unlaminated printed circuit board is sandwiched between the pads. As the press closes, the pads distribute pressure evenly across the board. They also buffer the PCB assembly from thermal shock as the platens heat.
Conventional padding consists of layers of brown Kraft paper. Before closing the press, the operator measures the stack and adds sheets until reaching the desired thickness. At the end of the lamination process, the paper is removed and thrown out, and the process is repeated.
In contrast, solid silicone press pads are supplied in the needed thickness and are reusable. "Less time is spent changing pads, so there is less downtime", Baushke said.