| 摘要 |
PURPOSE:To prevent a sealing glass from cracking by providing integrally a projection planely disposed corresponding to the peripheral edge of a sealing cap on a substrate formed with metallized layer of an insulating substrate, and mounting the cap in hermetically sealing manner with sealing glass at the projection. CONSTITUTION:A projection 9 formed in a square frame shape along the periphery of a transparent window 3a of plane shape is integrally formed corresponding to the peripheral edge of a cap 6 on an insulating substrate 3. The projection 9 is formed by baking with the same ceramic as the substrate 3 in thickness slightly larger than that of a metalized layer 4 or external leads 8. The cap 6 is bonded at the peripheral edge by sealing glass 7 made of low melting point glass on the projection 9. Thus, the sealing glass does not generate cracking even by thermal stress due to the thermal expansion difference between a heat sink plate and the substrate. |
