Appeal No. 95-4927
Serial No. 08/216,772
tip ends to be separated by a distance greater than the
selected value: "the distance between all uninsulated portions
of any pair of leads is always greater than the selected
distance value between the tip ends" (our emphasis). The
claims stand rejected under 35 U.S.C. § 103 as unpatentable
for obviousness over Mizuguchi in view of Yasui. Figure 1 of
Mizuguchi shows a prior art resin-encapsulated semiconductor
device which includes external leads 2-4 extending in what
appears to be a single plane from a resin housing 1.
Referring to Figure 2, which is an internal view of the prior
art device, the center lead 3 has two 90E bends therein so
that its outer portion lies in the same plane as leads 2 and
4, which are flat. The inner ends of leads 2 and 4 are
connected by internal leads 6 and 7 to the semiconductor
element 5. Mizuguchi attributes two problems to this prior
art construction. The first is that linear shape of the outer
leads 2 and 4 minimizes the amount of the leads that is
covered by the resin mold, thereby reducing the support
strength of the leads (translation at p. 3, lines 15-19). The
second is that the large vertical distance between the
semiconductor element and the inside ends of leads 2 and 4
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