Probe Pin Materials｜TANAKA Precious Metals

Probe Pin Materials

Product image of Probe Pin Materials

Precious metal probe pin materials used in the inspection process of semiconductor manufacturing.

A wide range of precious metal materials are available as probe pins for inspections conducted in the front-end and back-end processes of semiconductor manufacturing.

Application for Probe Pin Materials

Semiconductor integrated circuits are subjected to current-carrying tests at each of the front-end and back-end processes of the manufacturing process.
The current-carrying test in the front-end process is called a wafer test, and a probe card is used. Probe cards use cantilever or vertical probe pins.
The current-carrying test performed in the back-end process is called the final test, and a test socket is used. Pogo pin type probe pins are used for the test sockets.
We offer a lineup of various probe pin materials, as the performance required in terms of mechanical properties such as hardness and bendability, and electrical properties such as electrical resistivity, etc., vary depending on the application.

[Application diagram of Probe Pin Materials] (Front-end-process) Wafer test - cantilever type/vertical type, (Backt-end-process) Final test - Pogo pin type

Types and Features of Probe Pins

Cantilever Type

(Features) These probe pins are used for probe cards for testing wiring boards with a terminal structure that works on the principle of a cantilever beam. The tip of the probe pin is tapered into a needle shape and bent.
(Material Requirements) Material hardness, linearity, electrical resistivity, bendability, etc.
(Wire diameter) Φ50～300µm

Vertical Type

(Features) These are used for probe cards for testing wiring boards with a terminal structure that works on the principle of buckling stress. The tip of the probe pin is processed into a needle or hemispherical shape, depending on the board.
(Material Requirements) Material hardness, linearity, electrical resistivity, bendability, etc.
(Wire diameter) Φ20～70µm

Pogo Pin Type

(Features) These are also called spring probes or contact probes. They are used for electric current inspection of ICs, electronic components, and printed circuit boards. The tip is processed into a shape that corresponds to the object to be inspected.
(Material Requirements) Material hardness, linearity, contact resistance, etc.
(Wire diameter) Φ500µm～1,000µm

Major Materials for Probe Pins

		SP-1	SP-2	SP-3	TK-1	TK-H	TK-FS	Rh	Ir
Composition [mass%]	Pd	35	–	43	40	45	55.8	–	–
	Ag	30	10	40	29.5	19.5	6.9	–	–
	Au	10	70	–	–	–	–	–	–
	Pt	10	5	0.5	–	–	–	–	–
	Others	Cu, Zn	Cu, Ni	Cu	Cu, others	Cu, others	Cu, others	Rh	Ir
Capable wire diameter [mm]		0.08-1.00	0.08-1.00	0.08-1.00	0.05-1.00	0.50-1.00	0.04-1.00	0.03-0.30	0.03-0.30
Electrical resistivity [µΩ・cm, @R.T.]		25.0	13.3	28.3	10.4	10.6	6.8	4.8	5.6
Electrical conductivity [%IACS]		6.9	13.0	6.1	16.6	16.3	25.4	35.9	30.8
Temperature coefficient of resistance [ppm]		299	420	–	814	1091	1346	–	–
Vickers hardness [HV]		300-350	300-360	-320	460-490	500-520	400-520	400-550	500-750
Tensile strength [MPa]		1210-1450	1210-1350	1140-1395	1550-1750	1470-1550	1250-1720	1400-1800	1700-3600
Elongation at failure [%]		1-2	1-2	1-2	2-3	1-2	8-13	1-2	1-2
Young’s modulus [GPa]		112	106	119	110	112	150	380	530
0.2%offset yield strength [MPa]		1160-1400	1100-1250	–	1410-1630	1360-1490	1180-1640	～1700	～3400
Elastic limit [MPa]		1110-1170	1050-1100	–	1100-1280	900-1100	1000-1500	～1350	～2900
Elongation at elastic limit [%]		0.9-1.3	0.8-1.0	–	1.5-1.7	0.7-0.9	0.8-1.1	0.3-0.6	0.4-0.6
90° bending times^*1 [times]		3-6	3-6	8.5	0-2	0-1	8-10	–	–
Remarks		ASTM B540 equivalent	–	–	–	–	Patent registered	Patent registered	Patent registered

*1:Repeated bending times to failure at 0.10mm in dia. (acc. to in-house standard)

The above is just an example, and we can also accommodate compositions not listed here, so please contact us for more information.

Developed Material（TK-FS）

Low electrical resistivity, high bendability, and a wide range of hardnesses are all achieved simultaneously.

There was no material in our existing products that could simultaneously achieve the three qualities of high hardness, low electrical resistivity, and high bendability, but we have succeeded in solving this problem with this product, making it possible to use the same material for various types of probe pins. This material can be applied to a wide range of probe pin types, such as the cantilever type and the vertical type for wafer testing (front-end process) probe cards.

Features

Achieves three qualities simultaneously: Vickers hardness of 500 or more, electrical resistivity of 7.0 µΩ・cm or less, and resistance to bending more than 10 times repeatedly (in-house standard).
Our unique processing technology enables adjustment to a wide range of Vickers hardness (400 to 520).
Higher elongation (8% to 13%) than TANAKA Kikinzoku Kogyo K.K.’s existing probe pin materials.

Performance of TK-FS (comparison with Major Materials for Probe Pins)

Comparison of Major Materials for Probe Pins (Vickers Hardness vs Electrical Conductivity)
Comparison of Major Materials for Probe Pins (Elongation at Failure)
Comparison of Major Materials for Probe Pins (90° Bending Times)
Features of TK-FS (High Bending Durability)
Schematic Diagram of Repeated 90° Bending Test