Patent Application
20070047210
The present invention relates in general to active electronic components and more particularly to the packaging of such components for thermal dissipation.
The availability of active components for traditional communication frequencies and power levels is severely limited. Current industry standard packages for low cost, high power electronic components, such as RF power FETs (field effect transistors), are particularly poor at removing excess heat from these components.
Most low cost, injected molded packages for power FETs attempt to remove heat from the component through a metal contact in the bottom of the package. The part is soldered to a circuit board and the heat is transferred from a flag to the opposite side of the board through plated via holes. The product chassis makes contact with the opposite side of the board to draw heat away from the component. This heat dissipation technique requires that the heat be transferred from the package through a layer of solder, via holes, another solder layer, a heat spreader, thermal media (tape or paste) and the product chassis. For packages that remove heat through via holes, a degradation in power amplifier (PA) efficiency and power level has been noted for outputs over 2 watts. Thus, products requiring good thermal performance and efficiency can not use these parts. While bare, untested die can be purchased and manufactured into custom packages, vendors are reluctant to sell untested die and the manufacturing and logistical problems associated with custom packaging approaches are very costly.
Accordingly, there is a need for an improved means of facilitating heat dissipation in a high power electronic component.
The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below, are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention.
Briefly in accordance with the present invention, there is provided herein a an assembly which takes an existing packaged high power electronic component and repackages it in an assembly that allows the heat to be removed through direct chassis contact with the top of the assembly. A high power electronic component can be operated at optimum power levels without degrading performance when contained in the assembly.
Referring to
When a packaged electronic component is contained in an assembly formed in accordance with the present invention, optimum operating performance can be achieved. Packaging assembly 100 allows a power amplifier to operate at maximum power levels without degradation in performance. For example, the 2 watt FET mentioned in the background was operated at an optimum power level of over 10 watts without degradation in performance. The layout of the pcb isolator 104 and contact ring 106 can be configured to adapt and align to other packaged high power components as well.
The packaging assembly of the present invention allows designers to use existing, tested, packaged die in a new way to meet high tier performance standards. Thus, the need to purchase bare, untested die is eliminated. Numerous components that would otherwise be off limits to designers can now be used without having to purchase unpackaged die. By being able to purchase the components in standard packages and incorporating these standard packages into an assembly formed in accordance with the present invention manufacturability and performance issues are eliminated. The packaging assembly formed in accordance with the present invention has proven to be particularly advantageous for high power amplifiers.
While the invention has been described in conjunction with specific embodiments thereof, additional advantages and modifications will readily occur to those skilled in the art. The invention, in its broader aspects, is therefore not limited to the specific details, representative apparatus, and illustrative examples shown and described. Various alterations, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Thus, it should be understood that the invention is not limited by the foregoing description, but embraces all such alterations, modifications and variations in accordance with the spirit and scope of the appended claims.
