Patent ID: 9543169
Date: 2017-01-10
CPC Classifications: H01L,Y10T

Claim:
1. A method of manufacturing a lead frame including: a die pad on which a semiconductor element is to be mounted; and a plurality of lead portions provided on a periphery of the die pad, the plurality of lead portions each having an internal terminal and an external terminal, the external terminal of the plurality of lead portions being arranged in an alternately staggered form such that the external terminal of a pair of lead portions adjacent to each other is alternatively located on an inside or an outside, the plurality of lead portions each having an inside region located on the inside of the external terminal, an outside region located on the outside of the external terminal, and an external terminal region having the external terminal formed on a rear surface of the external terminal region, the method comprising: preparing a metal substrate; and forming the die pad and the lead portions in the metal substrate by way of etching the metal substrate, wherein when the die pad and the lead portions are formed in the metal substrate, the inside region and the outside region of the lead portion, bearing at least the external terminal on the inside, each have a rear surface formed in such a manner that the inside region and the outside region are thinner than the external terminal region, and wherein a maximum thickness of the outside region of the lead portion with the external terminal located on the inside is larger than a maximum thickness of the inside region of the lead portion with the external terminal located on the inside.