# US 8,787,028 B2 · Terminal structure, printed circuit board, module board, electronic device, and method for manufacturing terminal structure

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- Number: US 8,787,028 B2
- Document ID: US8787028B2
- Status: Granted
- Kind: B2
- Application number: 13/677,432
- Filed: 2012-11-15
- Published: 2013-05-30
- Granted: 2014-07-22
- Earliest claimed: 2011-11-30
- Assignees: TDK Corporation
- Applicants: TDK Corporation
- Inventors: Yuhei Horikawa; Shin Fujita; Kenichi Yoshida; Hisayuki Abe; Makoto Orikasa; Hideyuki Seike
- Web page: https://patentgrep.com/patent/US8787028B2

## CPC

- H05K 1/11: Printed elements for providing electric connections to or between printed circuits
- H01R 4/02: Soldered or welded connections {(H01R4/625, H01R4/723, H01R12/59 take precedence)}
- H01R 43/00: Apparatus or processes specially adapted for manufacturing, assembling, maintaining, or repairing of line connectors or current collectors or for joining electric conductors (of trolley lines B60M1/28)
- H05K 3/3436: {having an array of bottom contacts, e.g. pad grid array or ball grid array components}
- H05K 1/111: {Pads for surface mounting, e.g. lay-out}
- H05K 1/141: {One or more single auxiliary printed circuits mounted on a main printed circuit, e.g. modules, adapters (H05K1/142 and H05K1/147 take precedence)}
- H05K 3/244: {Finish plating of conductors, especially of copper conductors, e.g. for pads or lands (selective plating methods H05K3/243; finish plating of conductors made by printing techniques H05K3/246; solder as finish H05K3/3465)}
- H05K 3/3494: Heating processes for reflow soldering
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- Y10T 29/49204: Contact or terminal manufacturing
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H01R: ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

The electronic device includes a terminal structure and a printed circuit board including the terminal structure. The terminal structure includes a solder-joint conductor region placed on a wiring conductor, an intermediate layer contacting with the conductor region, and a solder region contacting with the intermediate layer. The intermediate layer includes an intermetallic compound including tin and at least one of copper and nickel as principal components. When the indentation elastic modulus of the conductor region is E1 and the indentation elastic modulus of the intermediate layer is E2, the ratio of E1 to E2 is equal to or more than 0.8 and equal to or less than 1.5.

## Claims

### Claim 1

A terminal structure comprising:
a solder joint conductor region placed on a wiring conductor;
an intermediate layer contacting with the conductor region; and
a solder region contacting with the intermediate layer,
wherein the intermediate layer comprises an intermetallic compound including tin and at least one of copper and nickel as principal components; and
wherein E1 and E2 satisfy the following expression (1):
0.8≦E1/E2≦1.5 (1),
where an indentation elastic modulus of the conductor region is E1 and an indentation elastic modulus of the intermediate layer is E2.

### Claim 2 (depends on 1)

The terminal structure according to claim 1, wherein the conductor region is copper or a copper-based alloy.

### Claim 3 (depends on 1)

The terminal structure according to claim 1, wherein the conductor region is nickel or a nickel-based alloy.

### Claim 4 (depends on 1)

The terminal structure according to claim 1, wherein when an indentation elastic modulus of the solder area is E3, E3 is smaller than E2.

### Claim 5 (depends on 2)

The terminal structure according to claim 2, wherein when an indentation elastic modulus of the solder area is E3, E3 is smaller than E2.

### Claim 6 (depends on 3)

The terminal structure according to claim 3, wherein when an indentation elastic modulus of the solder area is E3, E3 is smaller than E2.

### Claim 7 (depends on 1)

A printed circuit board comprising the terminal structure according to claim 1.

### Claim 8 (depends on 7)

A module board comprising the printed circuit board according to claim 7.

### Claim 9 (depends on 8)

An electronic device comprising the module board according to claim 8.

### Claim 10

A method for manufacturing a terminal structure, the method comprising:
a step of preparing a terminal structure including a solder joint conductor region placed on a wiring conductor, an intermediate layer contacting with the conductor region, and a solder region contacting with the intermediate layer;
a step of measuring the indentation elastic modulus of the conductor region;
a step of measuring the indentation elastic modulus of the intermediate layer;
a step of judging whether resistance to drop impact of the terminal structure is favorable based on a value of the indentation elastic modulus of the conductor region and a value of the indentation elastic modulus of the intermediate layer; and
a step of producing a terminal structure under the same condition as a production condition of the terminal structure that has been judged to show favorable resistance to drop impact at the step of judging.

### Claim 11 (depends on 10)

The method for manufacturing a terminal structure according to claim 10, wherein the intermediate layer comprises an intermetallic compound including tin and at least one of copper and nickel as principal components.