Semiconductor sensor with protective cap covering exposed conductive through-holes

• US 5,852,320 A
• Filed: 08/15/1996
• Issued: 12/22/1998
• Est. Priority Date: 02/19/1996
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Ichihashi, Motomi
• Primary Examiner(s): MEIER, STEPHEN D
• Application Number:
  US08/698,321
• Time in Patent Office: 859 Days
• Field of Search: 257/415, 257/418, 257/419, 257/686, 257/698, 257/700, 257/704, 257/711, 257/417
• US Class Current: 257/419
• CPC Class Codes: G01L 19/0038 being part of the housing other details about the housing G01L19/14
• CPC Class Codes: G01L 19/0084 to the outside of the housing other details about the housing see G01L19/14
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/92247 the second connecting process involving a wire connector
• CPC Class Codes: H01L 2924/01046 Palladium [Pd]
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/16151 Cap comprising an aperture, e.g. for pressure control, encapsulation
• CPC Class Codes: H01L 2924/16152 Cap comprising a cavity for hosting the device, e.g. U-shaped cap

Abstract

A semiconductor sensor comprising a substrate having thick-film conductors formed on both sides of the substrate, a semiconductor sensor chip having a diaphragm to which a pressure to be detected is applied and a pan-shaped cap bonded to the mounting side of the substrate with a die bond agent, further comprises plural through-holes pierced through the substrate, conductors formed in plural through-holes which connect the thick-film conductors to each other, bonding electrodes formed from a thick-film conductor on the mounting side of the substrate, each being connected to the thick-film conductor of the mounting side of the substrate and to the semiconductor sensor chip by a wire bonding, and a protection glass film formed on the thick-film conductor of the mounting side having apertures for forming exposed conductor portions of the thick-film conductor, wherein the opening of each through-hole and the exposed conductor portions are disposed at the position to which the cap is bonded and covered by the die bond agent for bonding the cap.

Claims

1. A semiconductor sensor comprising:

a substrate having a mounting side, a non-mounting side, and through-holes pierced through said substrate to connect said mounting and non-mounting sides;

a semiconductor sensor chip with a pedestal mounted on a mounting surface of said substrate mounting side with die bond agent;

a pan-shaped cap bonded by an adhesive to said mounting surface to cover said semiconductor sensor chip;

thick-film conductors connected to each other by conductors formed on the walls of said through-holes and formed in a specific pattern on both sides of said substrate;

bonding electrodes connected to said thick-film conductors of the mounting side of said substrate, and connected to said semiconductor sensor chip by wire bonding; and

a protective glass film forming a protective layer directly over said through-holes and portions of said thick-film conductors, other portions of said thick-film conductors remaining uncovered by said protective glass film thus forming exposed conductors;

wherein the through-holes and exposed conductors formed on the mounting side are disposed at the position to which the cap is bonded to the substrate, and

the through-hole openings on the mounting side are each directly covered by and in contact with a protective composite formed of a portion of said protective glass film and the adhesive directly covering the portion of said protective glass film, and the exposed conductors on the mounting side are directly in contact with and covered by the adhesive.

2. A semiconductor sensor for detecting a pressure applied thereto comprising:

a substrate having a mounting side, a non-mounting side, and through-holes pierced through said substrate to connect said mounting and non-mounting sides;

a semiconductor sensor chip having a diaphragm formed in the center thereof;

a pan-shaped cap bonded on said substrate by an adhesive to cover said sensor chip, said sensor chip being supported with a pedestal bonded on a mounting surface of said substrate mounting side with a die bond agent, the pressure being applied to said diaphragm through a pressure conveyance hole of said substrate and a pressure conveyance hole formed through said pedestal;

thick-film conductors connected to each other by conductors formed on the walls of the through-holes and formed in a specific pattern on both the mounting and non-mounting sides of the substrate;

bonding electrodes connected to said thick-film conductors of the mounting side of the substrate, and connected to the semiconductor sensor chip by wire bonding; and

a protective glass film forming a protective layer directly over said through-hole openings and portions of said thick-film conductors, other portions of said thick-film conductors remaining uncovered by said protective glass film thus forming exposed conductors;

wherein the through-hole openings on the mounting side and the exposed conductors on the mounting side are disposed at the position to which the cap is bonded to the substrate so that each through-hole opening on the mounting side is directly covered by and in contact with a protective composite formed of a portion of said protective glass film and the adhesive covering the portion of said protective glass film, and said exposed conductors are directly in contact with and covered by the adhesive.

3. The semiconductor sensor according to claim 2 further comprising:

a first dike formed on the mounting side as a wall of at least one thick-film layer to encircle the outside circumference of said pressure conveying hole of said substrate,

said first dike preventing the die bond agent from flowing into the pressure conveying holes in the pedestal and the substrate.

4. The semiconductor sensor according to claim 3 further comprising:

a second dike formed as a wall of at least one thick-film layer between said pedestal and the bonding electrodes, said second dike preventing the die bond agent from flowing over the bonding electrodes.

5. The semiconductor sensor according to claim 2 further comprising positioning marks on the mounting side of the substrate indicating the position to which the cap is to be bonded to the substrate.

6. The semiconductor sensor according to claim 5, wherein the positioning marks are formed from a thick-film conductor.

7. A semiconductor sensor comprising:

a substrate having a mounting side, a non-mounting side, and through-holes connecting said mounting and non-mounting sides;

a sensor unit adhered to said mounting side with a bonding agent;

a protective cap adhered to said mounting side with an adhesive, said protective cap covering and forming a boundary around said sensor unit at the location where said cap is adhered to said mounting side, the boundary of said protective cap being positioned over said through-holes such that said through holes are beneath said adhesive;

a plurality of thick-film conductors formed on respective surfaces of said mounting and non-mounting sides to form a specific pattern;

bonding electrodes located on said mounting side, said bonding electrodes connected to said sensor unit and said thick-film conductors located on said mounting side surface;

a glass film forming a protective layer over said through-holes and portions of said thick-film conductors, other portions of said thick-film conductors remaining uncovered by said glass film, the uncovered portions of said thick-film conductors on said mounting side being positioned under the boundary of said protective cap such that these uncovered portions are directly in contact with and covered by said adhesive, wherein said through-holes are directly covered by and in contact with a protective composite formed of a portion of said glass film and said adhesive directly covering the portion of said glass film.

8. A semiconductor sensor according to claim 7 wherein said substrate includes a pressure conveying through-hole aligned with said sensor unit.

9. A semiconductor sensor according to claim 8, further comprising:

a dike forming a barrier around said pressure conveying through-hole, said dike preventing the bonding agent used to adhere said sensor unit to said mounting side from leaking into said pressure conveying through-hole.

10. A semiconductor sensor according to claim 7, further comprising:

a dike forming a barrier between said bonding electrodes and said sensor unit, said dike preventing the bonding agent used to adhere said sensor unit to said mounting side from leaking onto said bonding electrodes.

11. A semiconductor sensor according to claim 7, further comprising:

a dike forming a barrier between said bonding electrodes and said protective cap, said dike preventing the adhesive used to adhere said protective cap to said mounting side from leaking onto said bonding electrodes.