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Japan’s  Polyplastics Co., Ltd. (U.S. office in Farmington Hills, Mich.) has been successfully using computer-aided engineering (CAE) analysis to forecast part deformation during the reflow process when manufacturing connector parts made of liquid crystal polymer (LCP). Such connectors are finding growing use in mobile devices such as smartphones and switches, along with automotive-related applications.

LCP parts can expand considerably in the high-temperature conditions of the reflow process, potentially affecting product flatness. Since heat deformation can cause poor bonding as a result of insufficient soldering to the metal terminals, it is important to find ways to reduce heat deformation, particularly as the market sees growing demand for smaller connectors.

Responding to this need, Polyplastics opted to employ CAE and began considering design stage deformation forecasting for molded articles in the reflow process. LCPs like Polyplastics’ Laperos resin, are characterized by rigid molecular structures that are hard to bend, and possess very little of the molecular interlocking behavior that is typical of most polymers. As a result, they deliver excellent dimensional accuracy and heat resistance, and handle high reflow temperatures in the solder bonding process.

The company has identified three stages of deformation that can be forecast by CAE analysis:

• Post-molding initial deformation (warpage)
• At-peak heat deformation mainly due to the effects of thermal expansion plus post-molding shrinkage
• Post-cooling deformation mainly attributed to the effects of thermal shrinkage.

Polyplastics plans to continue to work on the development of CAE analysis technology to improve its accuracy and expand its range of applicability.