OKI Launches Rigid-Flex PCBs with Embedded Copper Coins Featuring Improved Heat Dissipation for Space Equipment Applications

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OKI Circuit Technology, the OKI Group’s printed circuit board (PCB) business company, has developed rigid-flex PCBs with embedded copper coins that offer improved heat dissipation for use in rockets and satellite-mounted equipment operating in vacuum environments. Sales will start in August 2025. Targeting the rapidly growing New Space market, the new PCBs not only resolve the issue of heat management for high heat-generating components, but also enable space savings and weight reductions and reduce mounting man-hours because they are connector-less. OTC is targeting annual sales of 20 million yen in FY2026.

Rigid-flex PCBs have a structure that combines a thin, light, soft, and durable flexible circuit board (FPC, Note 1) made from insulating film, with a high-strength rigid PCB. This structure allows bending for installation in tight spaces inside equipment. Since no connectors are required to link the boards, these PCBs allow for space savings, weight reductions, and reductions in mounting man-hours. On the other hand, as the higher performance of components mounted on PCBs generates more heat, effective heat dissipation measures have become an issue in vacuum environments like space, where no convective heat dissipation occurs.

OTC has resolved this heat dissipation issue for rigid PCBs using its proprietary PCB technology with copper coin insertion whereby cylindrical-shaped copper coins with high thermal conductivity (Note 2) are inserted into PCB through-holes (Note 3) and bonded to heat-generating components to dissipate heat to the underside of the PCB. Applying this technology to rigid-flex PCBs has made it possible to create rigid-flex PCBs with embedded copper coins that demonstrate high heat dissipation performance in vacuum environments.

Having gained certification for all seven schedules of the JAXA (Japan Aerospace Exploration Agency) PCB standards, OTC offers strong expertise and highly reliable technologies for PCBs for use in space equipment. In addition, OTC can flexibly accommodate the small-lot production of PCBs to meet differing specification requirements according to the shape, size, and mounting location, allowing it to supply products for use at stages from development and prototyping to mass production. In its Medium-Term Business Plan 2025, OKI designates the aerospace market as a strategic focus for its EMS business. Drawing on its space-quality manufacturing capabilities, not only in design and production, but also simulations at the equipment design phase, OKI is working to expand technological development and sales in the global aerospace market.

OTC will exhibit at the Japan Booth of the Small Satellite Conference to be held from August 10 to August 13, 2025, at the Salt Palace Convention Center in Utah, USA, where it will showcase its rigid-flex PCBs with embedded copper coins.