ELECTRONIC COMPONENT, MANUFACTURING METHOD FOR ELECTRONIC COMPONENT, AND ELECTRONIC DEVICE

• US 20100290201A1
• Filed: 04/13/2010
• Published: 11/18/2010
• Est. Priority Date: 05/13/2009
• Status: Active Grant

• Current Assignee: Seiko Instruments Incorporated (Seiko Group)
• Original Assignee: SII Crystal Technology Inc. (Seiko Group)
• Inventors: Sato, Keiji, Aratake, Kiyoshi, Sugiyama, Takeshi, Numata, Masashi, Takeuchi, Hitoshi, Terada, Daisuke, Nakamura, Takahiko
• Granted Patent: US 8,441,799 B2
• Time in Patent Office: Days
• US Class Current: 361/752
• CPC Class Codes: H01L 23/055 the leads having a passage through the base H01L23/057 takes precedence
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/19041 being a capacitor
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49124 On flat or curved insulated base, e.g., printed circuit, etc.

Abstract

To provide an improved solderability for mounting an electronic component onto a circuit board, a package of an electronic component (1) is formed by bonding together a base (3) made of glass and a lid (2). Outer electrodes (8) and (18) are formed on a bottom surface of the base (3), and the outer electrodes (8) and (18) are respectively connected to through electrodes (7) and (17). The outer electrodes (8) and (18) each have a laminated structure of three CrAu layers, that is, from a Cr layer (first layer) to an Au layer (sixth layer). When the outer electrodes (8) and (18) are soldered onto a circuit board, the Au layers as the second, fourth, and sixth layers are dissolved into solder, whereas the Cr layers as the third and fifth layers, which hardly form an intermetallic compound with solder, are separated to remain in solder.

Claims

1. An electronic component, comprising:

an electronic element;

a housing case for housing the electronic element in a hollow portion defined inside the housing case;

via electrodes that are electrically connected to electrodes of the electronic element,

the via electrodes being formed from an inside of the housing case to an outside of the housing case; and

outer electrodes that are electrically connected to the via electrodes,

the outer electrodes being formed on a bottom surface of the housing case,

wherein the outer electrodes are each formed by including;

a first metal layer that is formed on the bottom surface of the housing case and is to be soldered to electrodes of a circuit board;

a second metal layer that is formed on a surface of the first metal layer and is to be dissolved into solder; and

a third metal layer that is formed on a surface of the second metal layer and is to be hardly dissolved into solder.

2. An electronic component according to claim 1, wherein the outer electrodes are each formed by further including:

a fourth metal layer that is formed on a surface of the third metal layer and is to be dissolved into solder; and

a fifth metal layer that is formed on a surface of the fourth metal layer and is to be hardly dissolved into solder.

3. An electronic component according to claim 1, wherein the outer electrodes each further include an anti-oxidation film formed as an outermost surface layer.

4. An electronic component according to claim 1, wherein the housing case is formed of glass.

5. An electronic component according to claim 1, wherein the electronic element comprises a crystal resonator.

6. A manufacturing method for an electronic component, comprising:

an electronic element installing step of installing, on a base, an electronic element and via electrodes for wiring to be electrically connected to electrodes of the electronic element;

an enclosing step of bonding a lid to the base on which the electronic element and the via electrodes are installed, to thereby enclose the electronic element in a housing case including the base and the lid; and

an outer electrode forming step of;

forming, on a bottom surface of the housing case, a first metal layer that is to be soldered to;

forming, on a surface of the first metal layer, a second metal layer that is to be dissolved into solder; and

forming, on a surface of the second metal layer, a third metal layer that is to be hardly dissolved into solder, to thereby form an outer electrode.

7. An electronic component, comprising:

an electronic element;

a housing case for housing the electronic element in a hollow portion defined inside the housing case;

via electrodes that are electrically connected to electrodes of the electronic element,

the via electrodes being formed from an inside of the housing case to an outside of the housing case;

a metal film for bonding that is electrically connected to one of the via electrodes and is to be soldered to electrodes of a circuit board,

the metal film for bonding being formed on a bottom surface of the housing case; and

an anti-oxidation film that is formed on a surface of the metal film for bonding,

wherein the anti-oxidation film includes at least one gold layer having a total thickness of 300 nm or more and 1,000 nm or less, and

wherein the at least one gold layer has an uppermost surface bonded to the metal film for bonding.

8. An electronic component according to claim 7, wherein the total thickness of the at least one gold layer is 300 nm or more and 450 nm or less.

9. An electronic component according to claim 7, wherein the anti-oxidation film includes:

a plurality of the gold layers; and

a predetermined metal layer that is formed between the plurality of the gold layers.

10. An electronic component according to claim 9, wherein the predetermined metal layer is made of a metal that is hardly dissolved into solder.

11. An electronic component according to claim 7, wherein the anti-oxidation film includes the at least one gold layer formed as a single layer.

12. An electronic component according to claim 7, wherein the housing case is formed of glass.

13. An electronic component according to claim 7, wherein the electronic element comprises a crystal resonator.

14. A manufacturing method for an electronic component, comprising:

an electronic element installing step of installing, on a base, an electronic element and via electrodes for wiring to be electrically connected to electrodes of the electronic element;

an enclosing step of bonding a lid to the base on which the electronic element and the via electrodes are installed, to thereby enclose the electronic element in a housing case including the base and the lid;

a metal film for bonding forming step of forming, on a bottom surface of the housing case, a metal film for bonding that is to be soldered to; and

an anti-oxidation film forming step of forming, on a surface of the formed metal film for bonding, an anti-oxidation film that includes at least one gold layer having a total thickness of 300 nm or more and 1,000 nm or less, the at least one gold layer having an uppermost surface bonded to the formed metal film for bonding.

15. An electronic device, comprising:

an electronic element;

a housing case for housing the electronic element in a hollow portion defined inside the housing case;

via electrodes that are electrically connected to electrodes of the electronic element,

the via electrodes being formed from an inside of the housing case to an outside of the housing case;

an electrode metal layer that is electrically connected to one of the via electrodes,

the electrode metal layer being formed on a bottom surface of the housing case;

a joint that is bonded to the electrode metal layer without forming an intermetallic compound layer of Sn between the joint and the electrode metal layer; and

a circuit board on which other electronic elements are mounted and to which the joint is bonded.

16. An electronic device according to claim 15, wherein the electrode metal layer is made of a metal selected from the group consisting of Cr, Ti, Mo, W, and Ta.

17. An electronic device according to claim 15, wherein the joint contains in a mixed state at least one metal selected from the group consisting of Cr, Ti, Mo, W, and Ta.

18. An electronic device according to claim 17, wherein the electrode metal layer is made of the same metal as the at least one metal contained in the joint in the mixed state.

19. An electronic device according to claim 15, wherein the joint contains Au.