Medical Device Link.

Originally Published EMDM September 2004

Technology News

Packages from Quantum Leap Packaging Inc. made of a liquid-crystal polymer formulation feature heat-dissipating flanges.

A new material produces a hermetic seal in plastic RF power packages when it is moulded using a company’s proprietary process. “This is the first time that a hermetic seal is possible in a nonmetallic package,” according to Mike Zimmerman, chief technical officer at Quantum Leap Packaging Inc. (Wilmington, MA, USA).

Existing plastic technologies are inexpensive, but they lack the robustness needed for critical applications. This is due in part to their inability to maintain a seal, notes Zimmerman. The company’s liquid-crystal polymer (LCP) formulation overcomes this limitation.

Hermeticity is critical in RF power packages. They contain a silicon microchip that is susceptible to dust and moisture. “A hermetic seal [prevents] environmental exposure that could cause the chip to fail prematurely,” says Zimmerman.

Compared with other materials, LCP offers enhanced reliability and performance. Its dielectric constant and loss properties—as low as 2.9–1.9 at 1 MHz—are lower than conventional materials. Moreover, the material’s structural properties permit thin-wall constructions, providing more room to house active and passive components while maintaining the industry-standard footprints of ceramic and metal packages. Standard mounting flanges are designed to dissipate heat produced by the device. Made of a special copper alloy, the flanges improve heat dissipation by 30% compared with typical copper material.

The company’s Ultraseal technology molecularly fuses the lid to the package body. A hermetic seal is created in less than 2 seconds. “The lid is welded to the package, eliminating the need for epoxies that require a 1-hour cure,” says Zimmerman. The technology accelerates production, reduces costs, and eliminates flow and outgassing problems associated with epoxies. 

The LCP RF power packages are available in strip form to facilitate automated assembly. Medical applications include new product development of portable electronic medical devices, such as handheld patient-monitoring modules, notebook-sized defibrillators, and mobile test equipment.

Copyright ©2004 European Medical Device Manufacturer