Silicone oil-filled semiconductor pressure sensor

• US 5,625,151 A
• Filed: 06/01/1995
• Issued: 04/29/1997
• Est. Priority Date: 12/27/1994
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Yamaguchi, Yasuo
• Primary Examiner(s): Chilcot, Richard
• Assistant Examiner(s): Oen, William L.
• Application Number:
  US08/456,306
• Time in Patent Office: 698 Days
• Field of Search: 73/716, 73/717, 73/718, 73/719, 73/720, 73/721, 73/722, 73/723, 73/724, 73/725, 73/726, 73/727, 73/756
• US Class Current: 73/716
• CPC Class Codes: G01L 19/04 Means for compensating for effects of changes of temperature , i.e. other than electric compensation
• CPC Class Codes: G01L 19/0645 using isolation membranes, specially adapted for protection
• CPC Class Codes: G01L 19/147 Details about the mounting of the sensor to support or covering means
• CPC Class Codes: G01L 23/24 specially adapted for measuring pressure in inlet or exhaust ducts of internal-combustion engines

Abstract

A semiconductor pressure sensor that can be inexpensively manufactured with a reduced number of assembly steps and without using spacers includes a stem having an upper surface on which are mounted a pedestal and a semiconductor pressure sensor chip of substantially the same area as that of the stem upper surface. The semiconductor pressure sensor chip and the pedestal include aligned lead insertion holes through which leads are inserted. While spacers have been used in the prior art to reduce vacant space in the sensor that is filled with silicone oil, the spacers can be dispensed with in the invention because the semiconductor pressure sensor chip and the pedestal have areas substantially the same as the stem upper surface and serve as spacers.

Claims

1. A semiconductor pressure sensor comprising:

a case having a central through hole and a metallic diaphragm covering the through hole;

a stem bonded to said case and defining a space between said case and said stem, said stem having an upper surface within and opposite said case and having an area;

a pedestal mounted on the upper surface of said stem, having an area nearly equal to the area of the upper surface of said stem and including lead insertion holes;

a semiconductor pressure sensor chip mounted on said pedestal, having an area nearly equal to the area of the upper surface of said stem, and including lead insertion holes aligned with the lead insertion holes in said pedestal, said semiconductor pressure sensor chip including a thin diaphragm;

leads extending through the lead insertion holes in said pedestal and said semiconductor pressure sensor chip and penetrating through said stem outwardly from said sensor;

wires connected to said semiconductor pressure sensor chip and to said leads; and

silicone oil filling the space between said case and said stem.

2. A semiconductor pressure sensor comprising:

a case having a central through hole and a metallic diaphragm covering the through hole;

a unitary stem bonded to said case and defining a space between said case and said stem, said stem having an upper surface within and opposite said case, an area, and an annular projection projecting from the upper surface within said case;

a pedestal mounted on the upper surface of said stem and surrounded by said protection;

a semiconductor pressure sensor chip mounted on said pedestal, surrounded by said projection, and having a thin diaphragm;

wires connected to said semiconductor pressure sensor chip;

leads connected to said wires and penetrating through said stem outwardly from said sensor; and

silicone oil filling the space between said case and said stem.

5. The semiconductor pressure sensor according to claim 2 wherein said leads penetrate through and extend from said projection within said case.

3. A semiconductor pressure sensor comprising:

a case having a central through hole and a metallic diaphragm covering the through hole;

a semiconductor pressure sensor chip, having a thin diaphragm, and bonded to said case such that said diaphragm is located opposite the central through hole;

a thick film substrate bonded with bump electrodes to a front surface of said semiconductor pressure sensor chip;

a retainer plate mounted to said thick film substrate and mounting said thick film substrate to said case;

leads connected to said thick film substrate; and

silicone oil filling the through hole and a space in said case between the through hole and said semiconductor pressure sensor chip.

4. The semiconductor pressure sensor according to claim 3 including an IC chip for amplification and temperature compensation mounted with bump electrodes to said thick film substrate.