1. Field of the Invention
The present invention relates to a lead frame and a resin-molded-type semiconductor device using the same.
2. Description of the Related Art
A resin-molded-type semiconductor has been conventionally used mainly for low-frequency purposes. On the other hand, for high-frequency purposes a ceramic package has been generally and widely used. When a high frequency signal is transmitted, since it is difficult to obtain a desired characteristic impedance in a lead frame, the wave shapes of such high-frequency signals may easily be deformed. Therefore, for a high-frequency semiconductor device, a ceramic package can appropriately be used, because the ceramic package is able to be adapted to the desired characteristic impedance. In addition, a ceramic package having multi-layered line patterns can be formed and, therefore, the characteristic impedance thereof can appropriately be matched by suitably designing the distance between adjacent layers or line patterns or the thickness of respective layers.
On the other hand, a lead frame for resin-molded-type semiconductors has not been designed in such a manner that the width of leads or the distance between the adjacent leads are in conformity with those values to obtain a desired characteristic impedance. Therefore, a deflection of a signal may occur due to the miss-matching of the characteristic impedance and, therefore, decay of signal or deformation of the signal wave shape may easily occur. Thus, in general, a conventional lead frame is inappropriate for a high-frequency semiconductor device.