Composition for sealing a semiconductor device, semiconductor device and method of manufacturing the same

#The present invention relates to a semiconductor device having a semiconductor element sealed with a resin, and more specifically, to a semiconductor device having a highly recyclable package. The present invention further relates to a thermoplastic resin composition excellent in adhesiveness to a carrier member such as a leadframe.

#Conventionally, it is known that a semiconductor device is formed by mounting a semiconductor element on a leadframe and thereafter sealing the semiconductor element with a thermosetting resin. Such a semiconductor device is formed as follows.

#A leadframe having a semiconductor element mounted thereon is placed in a cavity formed by combining an upper mold and a lower mold. The semiconductor element is electrically connected to the leadframe by, for example, a bonding wire. Then, an epoxy resin (thermosetting resin) is injected through an injection port (gate) facing within the cavity. The epoxy resin thus injected is heated to solidify, with the result that the semiconductor element and the leadframe are integrated into one body. As described, the thermosetting resin is widely employed in manufacturing the semiconductor device since the thermosetting resin has a good flowability and adhesiveness.

#The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.

#FIGS. 1A and 1B respectively showing a front view and a side view of a semiconductor device according to a first embodiment of the present invention;

#FIG. 2 is a graph showing the bending strength versus a weight ratio of thermoplastic resin PPS (polyphenylene sulfide) to an adhesion properties imparting agent;

#Now, the present invention will be explained with reference with the accompanying drawings.

#FIGS. 1A and 1B show a constitution of a transistor device 10 according to a first embodiment of the present invention. In the transistor device 10, a bed portion 12 of a leadframe 11 formed of a conducting member such as copper having a good conductivity, is exposed from a package 20 in order to efficiently dissipate heat derived from inside the device. The package 20 is integrally molded into one body with the leadframe 11, the bonding wire 15, and a semiconductor element 14. The package 20 is formed by solidifying a sealing resin composition. When it is not necessary to dissipate heat, the bed portion 12 is not necessary to protrude out of the package 20.

#The leadframe 11 has the bed portion 12 (flat board) having the semiconductor element mounted thereon and a lead portion 13 protruding from an end of the bed portion 12 in contact therewith. To prevent sliding of the bed portion 12 with the package 20, a mooring portion 12a of an uneven structure is arranged in a longitudinal direction of the leadframe.