This invention relates to a light-receiving module in which transmission impedance
of lead terminals are matched by simple method. The module has a semiconductor
light-receiving device, such as a photo diode, a plurality of lead terminals for
transmitting an electrical signal converted by the semiconductor device, and a
metal base with a plurality of through holes, the lead terminals passes therethrough.
The diameter of the lead terminal for signal transmission is smaller as compared
with that of other lead terminal and the diameter of the through holes is adjusted
and filled by a sealant glass with a dielectric constant so as to match the impedance thereof.
