INERTIAL SENSOR AND METHOD OF MANUFACTURING THE SME

• US 20130118258A1
• Filed: 10/12/2012
• Published: 05/16/2013
• Est. Priority Date: 11/10/2011
• Status: Abandoned Application

• Current Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kang, Yun Sung, Kim, Jong Woon
• Application Number:
  US13/650,532
• Publication Number:
  US 20130118258A1
• Time in Patent Office: Days
• US Class Current: 73/514.35
• CPC Class Codes: G01C 19/5755 the devices having a single sensing mass
• CPC Class Codes: G01C 19/5769 Manufacturing; Mounting; Housings
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/09 by piezoelectric pick-up
• CPC Class Codes: Y10T 29/42 Piezoelectric device making

Abstract

Disclosed herein are an inertial sensor and a method of manufacturing the same. The inertial sensor includes: a flexible part; a mass body movably supported by the flexible part and including a metal; a post supporting the flexible part; piezoelectric elements driving the mass body or sensing displacement of the mass body; and a package enclosing the flexible part, the mass body, and the post, wherein the metal has a melting point lower than the Curie temperature of the piezoelectric elements and higher than that of a solder forming connection parts for a surface mounting technology (SMT) provided on the package.

Claims

1. An inertial sensor comprising:

a flexible part;

a mass body movably supported by the flexible part and including a metal;

a post supporting the flexible part;

piezoelectric elements driving the mass body or sensing displacement of the mass body; and

a package enclosing the flexible part, the mass body, and the post,

wherein the metal has a melting point lower than the Curie temperature of the piezoelectric to elements and higher than that of a solder forming connection parts for a surface mounting technology (SMT) provided on the package.

2. The inertial sensor as set forth in claim 1, wherein the piezoelectric element is formed of lead zirconate titanate (PZT), barium titanate (BaTiO₃), lead titanate (PbTiO₃), lithium niobate (LiNbO₃), or quartz (SiO₂).

3. The inertial sensor as set forth in claim 1, wherein the solder forming the connection part for an SMT has a ratio of tin (Sn) to lead (Pb) of 63%:

37%.

4. The inertial sensor as set forth in claim 1, wherein the metal is a solder having a melting point higher than that of the solder forming the connection part for an SMT.

5. The inertial sensor as set forth in claim 1, wherein the metal is a solder formed of tin (Sn) and lead (Pb), and the solder has a melting point higher than a eutectic temperature of tin (Sn) and lead (Pb).

6. The inertial sensor as set forth in claim 1, wherein the mass body includes an interface layer formed therein.

7. An inertial sensor comprising:

a flexible part;

a mass body movably supported by the flexible part and including a metal;

a post supporting the flexible part;

piezoelectric elements driving the mass body or sensing displacement of the mass body; and

connection parts for an SMT provided on the package enclosing the flexible part, the mass body, and the post and formed using a solder,

wherein the metal has a melting point lower than the Curie temperature of the piezoelectric elements and higher than that of the solder forming the connection parts for an SMT.

8. The inertial sensor as set forth in claim 7, further comprising a main board electrically connected to the connection parts for an SMT.

9. A method of manufacturing an inertial sensor, the method comprising:

(A) forming piezoelectric elements on one surface of a base substrate;

(B) forming a first concave part in the other surface of the base substrate;

(C) forming a mass body in the first concave part by filling a filling material including a metal therein;

(D) forming a depressed second concave part in the other surface of the base substrate at an outer side of the mass body and forming a flexible part on an upper portion of the second concave part in the base substrate; and

(E) enclosing the base substrate with a package and forming connection parts for an SMT on the package, the connection parts for an SMT being formed using a solder,

wherein the metal has a melting point lower than the Curie temperature of the piezoelectric elements and higher than that of the solder forming the connection parts for an SMT.

10. The method as set forth in claim 9, wherein the piezoelectric element is formed of lead zirconate titanate (PZT), barium titanate (BaTiO₃), lead titanate (PbTiO₃), lithium niobate (LiNbO₃), or quartz (SiO₂).

11. The method as set forth in claim 9, wherein the solder forming the connection part for an SMT has a ratio of tin (Sn) to lead (Pb) of 63%:

37%.

12. The method as set forth in claim 9, wherein the metal is a solder having a melting point higher than that of the solder forming the connection part for an SMT.

13. The method as set forth in claim 9, wherein the metal is a solder formed of tin (Sn) and lead (Pb), and the solder has a melting point higher than a eutectic temperature of tin (Sn) and lead (Pb).

14. The method as set forth in claim 9, further comprising, before step (C), forming an interface layer in the first concave part.

15. A method of manufacturing an inertial sensor, the method comprising:

(A) forming piezoelectric elements on one surface of a base substrate;

(B) forming a penetration part penetrating through the base substrate;

(C) forming a mass body in the penetration part by filling a filling material including a metal therein;

(D) forming a flexible part patterned so as to penetrate through the base substrate at an outer side of the mass body; and

(E) enclosing the base substrate with a package and forming connection parts for an SMT on the package, the connection parts for an SMT being formed using a solder,

wherein the metal has a melting point lower than the Curie temperature of the piezoelectric elements and higher than that of the solder forming the connection parts for an SMT.

16. The method as set forth in claim 15, wherein the piezoelectric element is formed of lead zirconate titanate (PZT), barium titanate (BaTiO₃), lead titanate (PbTiO₃), lithium niobate (LiNbO₃), or quartz (SiO₂).

17. The method as set forth in claim 15, wherein the solder forming the connection part for an SMT has a ratio of tin (Sn) to lead (Pb) of 63%:

37%.

18. The method as set forth in claim 15, wherein the metal is a solder having a melting point higher than that of the solder forming the connection part for an SMT.

19. The method as set forth in claim 15, wherein the metal is a solder formed of tin (Sn) and lead (Pb), and the solder has a melting point higher than a eutectic temperature of tin (Sn) and lead (Pb).

20. The method as set forth in claim 15, further comprising, before step (C), forming an interface layer in the penetration part.