Surface mount type package unit

• US 6,388,887 B1
• Filed: 11/28/2000
• Issued: 05/14/2002
• Est. Priority Date: 12/27/1993
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Matsumoto, Masahiro, Miki, Masayuki, Suzuki, Seikou
• Primary Examiner(s): Picard, Leo P.
• Assistant Examiner(s): FOSTER, DAVID A
• Application Number:
  US09/722,564
• Time in Patent Office: 532 Days
• Field of Search: 361/760, 361/728, 361/736, 361/737, 361/743, 361/748, 361/763, 361/767, 361/772, 361/764, 361/783, 734/93, 737/56, 734/31, 735/143.5, 735/140.1, 257/678, 257/690, 257/692, 257/723, 257/724, 438/53, 174/260, 174/250, 174/255, 174/52.5
• US Class Current: 361/760
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: G01P 2015/0828 the mass being of the paddle type being suspended at one of its longitudinal ends
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details

Abstract

An acceleration sensor is disclosed which includes a capacitance-type acceleration detection element mounted on a ceramic base plate. The element comprises a movable electrode mounted between a pair of fixed electrodes. Acceleration of the sensor in a measurement direction causes the movable electrode to move relative to the fixed electrodes and the element has opposite ends in a direction perpendicular to the measurement direction. The acceleration detection element is mounted on the base at a first one of the opposite ends. Accordingly, the mounting surface of the acceleration sensor is parallel to the direction of acceleration to be detected. Thus the acceleration sensor can be surface-mounted on a printed board, and more be easily mounted in an automobile air bag control system or the like.

Claims

1. A surface mount type package unit comprising:

a circuit board;

a conductive member provided on the circuit board;

a package body having a mounted surface and mounted on the circuit board with the mounted surface facing the circuit board through the conductive member;

a circuit element held on the package body;

a first conductor provided on the mounted surface of the package body adjacently to an end portion of the mounted surface and electrically connected to the circuit element, the first conductor directly connected to the conductive member of the circuit board through solder; and

a second conductor provided on the mounted surface of the package body and connected to the conductive member of the circuit board through solder;

wherein the solder connecting the first conductor and the conductive member is exposed to an outside of the mounted surface of the package body when the first conductor is joined to the conductive member through the solder; and

wherein a clearance between the package body and the circuit board is held by the first conductor or the second conductor connected to the conductive member by the solder.

2. The surface mount type package unit according to claim 1, wherein the first conductor has a shape extending from an inner portion of the mounted surface to an end portion of the mounted surface.

3. The surface mount type package unit according to claim 1, wherein the circuit board has a main surface on which the package body is mounted, and the main surface of the circuit board is substantially parallel to the mounted surface of the package body.

4. The surface mount type package unit according to claim 1, wherein an area of the mounted surface of the package body is the largest of all surfaces of the package body.

5. The surface mount type package unit according to claim 1, wherein the second conductor is arranged on the mounted surface at a distance from a center of the mounted surface.

6. The surface mount type package unit according to claim 1, wherein the circuit element includes a circuit for processing an electrical signal of a sensor.

7. The surface mount type package unit according to claim 6, wherein the circuit element includes an element for converting a dynamic amount into an electrical signal.

8. The surface mount type package unit according to claim 7, wherein the dynamic amount is an amount of acceleration.

11. The method for manufacturing a surface mount type package unit according to claim 7, wherein the second conductor is formed on the mounted surface of the package body at a distance from a center of the mounted surface.

9. A method for manufacturing a surface mount type package unit including a package body directly mounted on a circuit board with solder, the method comprising steps of:

forming a first conductor on a mounted surface of the package body;

forming a second conductor on the mounted surface of the package body to be in a non-contacting state with respect to the signal electrode;

preparing the circuit board having a conductive member on a surface thereof; and

bonding the first conductor and the second conductor of the package body to the conductive member of the circuit board by solder.

10. The method for manufacturing a surface mount type package unit according to claim 9, the first conductor and the second conductor are formed in the same process.

12. A surface mount type package unit comprising:

a circuit board;

a package body mounted on the circuit board, the package body having a mounted surface facing the circuit board and a secondary surface adjacent to the mounted surface, the secondary surface being non-parallel to the mounted surface;

a circuit element held on the package body;

a first conductor provided on the mounted surface of the package body to face the circuit board, and electrically connected to the circuit element;

a first solder portion provided between the first conductor and the circuit board to make contact between the first conductor and the circuit board;

a second conductor provided on the mounted surface of the package body to face the circuit board, and electrically insulated from the first conductor and the circuit board; and

a second solder portion provided between the second conductor and the circuit board.

13. The surface mount type package unit according to claim 12, wherein the second solder portion is exposed to the outside of the package unit.