| 摘要 |
1,094,134. Semi-conductor devices. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. June 29, 1965 [May 7, 1964], No. 19053/64. Heading H1K. The intersection of a junction with the surface of the silicon or germanium body containing it lies within a sealed duct whose cross-section is formed in part by the body and in part by a member of insulating material such as glass. Openings into the duct are used to introduce liquid or gaseous etchants for cleaning the junction. Etchants are removed before sealing and may be replaced by a gaseous, liquid, or subsequently solid insulating filler. A getter material may be placed within the duct. The semi-conductor device may be a thyristor but the embodiments described are diodes. Figs. 1 and 2 (not shown), illustrate a semi-conductor body with a junction parallel to its major faces and mounted within a glass tube sealed to the body at its major faces while leaving the surface portion of the junction exposed within the tube. Etchant, flushant, and if desired, a filler are passed through the tube which is then sealed off. Nickel electrodes may be plated on to the major faces through holes cut in the glass. The embodiment of Fig. 3 (not shown), has a glass annulus (16) sealed to a silicon wafer (11) and a semi-conductor plate (14) bonded to the mesa of the wafer and to the annulus. Holes (18) in the plate allow etchant &c. to be introduced into the duct (17) which is subsequently sealed by a gold-silicon alloy body or by further silicon plate (19) bonded to the first plate by gold-silicon solder. Several of these devices may be formed on a single silicon body which is divided after completion of the devices. In a modification, the first plate (14) is in the form of an annulus mounted with its upper surface flush with the mesa of the wafer. The embodiment of Fig. 8 (not shown), has a silicon wafer in the shape of a flanged spool with its groove sealed by a glass ring. The PN junction, which is parallel to the flanges, may be formed at the same time as the ring is fused to the body or may be formed subsequently by diffusion through one of the flanges. Holes are formed in one of the flanges to introduce the etchant &c. and are sealed by a silicon plate. Electrodes are applied to the plate and to the free face of the wafer. Fig. 4 shows semi-conductor wafer 20 bonded between a finned heat sink 35 and braided conductor 36. The braided conductor may be replaced by a plurality of coiled copper conductors connected in parallel. An annular glass duct is bonded to the periphery of the major face of the wafer and etchant introduced through one or more tubes 23 to form or enlarge a previously formed groove exposing the junction. The variants of Figs. 6 and 7 (not shown), have heat sinks of smaller diameter than the wafer. In one, instead of tubes, holes are drilled through the insulating member. In the other (Fig. 7) access to the duet is by holes drilled through the semi-conductor wafer. The holes in these embodiments are sealed by semi-conductor plates. |
