Pin terminal, connector, wiring harness with connector and control unit

Patent metadata

Field	Value
Publication number	US-2022393375-A1
Application number	US-202017760693-A
Country	US
Kind code	A1
Filing date	Aug 31, 2020
Priority date	Sep 19, 2019
Publication date	Dec 8, 2022
Grant date	—

Abstract

A pin terminal includes a bar-like base material and a plating layer covering a predetermined region of the base material. A constituent material of the base material is pure copper or a copper alloy. The plating layer includes a tin-based layer made of metal containing tin. One end side of the base material includes a tip covering portion covering an entire region in a circumferential direction of the base material. The tin-based layer includes the tip covering portion. The tip covering portion includes a thin film portion and a thick film portion at positions different in the circumferential direction of the base material. The thin film portion is provided in contact with the base material. The number of whiskers present on a surface of the thin film portion is 15 or less in a square visual field having one side length of 0.35 mm.

First claim

1 . A pin terminal, comprising:
a bar-like base material; and a plating layer covering a predetermined region of the base material, wherein: a constituent material of the base material is pure copper or a copper alloy, the plating layer includes a tin-based layer made of metal containing tin, one end side of the base material includes a tip covering portion covering an entire region in a circumferential direction of the base material, the tin-based layer includes the tip covering portion, the tip covering portion includes a thin film portion and a thick film portion at positions different in the circumferential direction of the base material, the thin film portion is provided in contact with the base material, the number of whiskers present on a surface of the thin film portion is 15 or less in a square visual field having one side length of 0.35 mm, and a maximum wetting force of the tip covering portion measured by a meniscograph tester is 0.25 mN or more.

2 . The pin terminal according to claim 1 , wherein:
the tip covering portion includes an outer layer and an inner layer, a constituent material of the outer layer is pure tin, and a constituent material of the inner layer is an alloy containing tin and copper.

3 . The pin terminal according to claim 2 , wherein:
a thickness of the outer layer in the thin film portion is 0.5 μm or more, and a thickness of the inner layer in the thin film portion is 0.1 μm or more.

4 . The pin terminal according to claim 1 , wherein a difference (t 1 −t 2 ) of a maximum value t 1 and a minimum value t 2 of a thickness of the tip covering portion measured at a measurement location set at a spot of 1 mm from one end of the pin terminal along a longitudinal direction of the pin terminal is 0.20 μm or more.

5 . The pin terminal according to claim 1 , wherein a ratio t 2 /t 1 of a maximum value t 1 and a minimum value t 2 of a thickness of the tip covering portion measured at a measurement location set at a spot of 1 mm from one end of the pin terminal along a longitudinal direction of the pin terminal is 0.20 or more and less than 0.8.

6 . The pin terminal according to claim 4 , wherein:
the thin film portion has the minimum value t 2 , and the thick film portion has the maximum value t 1 .

7 . The pin terminal according to claim 4 , wherein, in a cross-section of a part provided with the tip covering portion in the base material cut by a plane orthogonal to an axis of the base material,
the base material has a rectangular shape, an outer peripheral surface of the base material has a first surface and a second surface arranged to face each other and a third surface and a fourth surface arranged to face each other, a part of the tip covering portion covering at least one of the first and second surfaces has the maximum value t 1 , and a part of the tip covering portion covering at least one of the third and fourth surfaces has the minimum value t 2 .

8 . The pin terminal according to claim 7 , wherein:
the plating layer includes an underlayer between parts of the tip covering portion covering the first and second surfaces and the base material, parts of the tip covering portion covering the third and fourth surfaces are provided in contact with the base material, and a constituent material of the underlayer is pure nickel or a nickel alloy.

9 . The pin terminal according to claim 7 , wherein, in the first, second, third and fourth surfaces, a spot of 1 mm, a spot of 3 mm and a spot of 5 mm from the one end of the pin terminal along the longitudinal direction of the base material are set as measurement locations for the thickness of the tip covering portion, a difference between a maximum thickness and a minimum thickness is taken at the three measurement locations, and a maximum value of the differences is 1.0 μm or less.

10 . The pin terminal according to claim 1 , wherein:
the constituent material of the base material is the copper alloy, and a Zn content in the copper alloy is 20% by mass or less.

11 . The pin terminal according to claim 1 , wherein:
the other end side of the base material includes a rear end covering portion and an exposed region at positions different in the circumferential direction of the base material, the tin-based layer includes the rear end covering portion, the rear end covering portion covers a partial circumferential region on the other end side of the base material, and the plating layer is not provided and the base material is exposed in the exposed region.

12 . A connector, comprising the pin terminal according to claim 1 .

13 . A wiring harness with connector, comprising:
the connector according to claim 12 ; and a wiring harness, the wiring harness being connected to the other end side of the pin terminal.

14 . A control unit, comprising:
the connector according to claim 12 ; and a circuit board, the circuit board and the region on the one end side of the pin terminal being connected by solder.

15 . The control unit according to claim 14 , wherein the circuit board controls at least one of engine fuel injection and engine ignition.

16 . A control unit, comprising:
the wiring harness with connector according to claim 13 ; and a circuit board, the circuit board and the region on the one end side of the pin terminal being connected by solder.

17 . The control unit according to claim 16 , wherein the circuit board controls at least one of engine fuel injection and engine ignition.

Assignees

• Autonetworks Technologies Ltd
• Sumitomo Wiring Systems
• Sumitomo Electric Industries

Inventors

• Sato Mikio
• Kato Akihiro
• Kumondai Mitsuhiro
• Saka Yoshifumi

Classifications

• H01R43/0256

  for soldering or welding connectors to a printed circuit board · CPC title

• H01R13/03 Primary

  characterised by the material, e.g. plating, or coating materials · CPC title

• H01R12/58 Primary

  terminals for insertion into holes · CPC title

• C25D7/00

  Electroplating characterised by the article coated · CPC title

• C25D5/505

  of electroplated tin coatings, e.g. by melting · CPC title