JP2011064663A - Probe pin for probe card - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a probe pin for probe cards that has improved performance on corrosion resistance, wear resistance, and the like, is elastic, and can be readily bent by providing a highly practical method of bonding a tip contact section to a body section, when manufacturing the tip contact section of the probe pin from a material with indium as the main component and manufacturing the body section from a material having improved bending properties, elasticity and electrical conductivity. <P>SOLUTION: The probe pin 21 for probe cards includes a probe pin 22 that includes a conical section 23, a cylindrical section 24 and a stepped shaft section 25 and is mainly made of indium; and a thin-walled pipe 26 made of a material having improved electrical conductivity and cold working properties, such as copper and beryllium, set in the stepped shaft section 25. An average surface roughness within a range of 0.5 to 5 micron, or metal plating having improved electrical conductivity, such as copper and nickel, is applied to the stepped shaft section 25. The thin-walled pipe 26 is heated and softened, and the inner surface bites into the surface roughness of the stepped shaft section 25 or is melted and is bonded to the metal plating and joints the probe pin 22 to the thin-walled pipe 26. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a probe pin for a probe card that performs an electrical continuity test of a semiconductor.

  Conventionally, as a probe pin for a probe card, iridium having excellent corrosion resistance and wear resistance is used for a tip portion in contact with a semiconductor inspection site, and beryllium copper is used for a body portion that requires elasticity, toughness and electrical conductivity. Probe pins using tungsten or tungsten as the main body material have been proposed.

  In fact, the probe card requires bending workability, electrical conductivity, and elasticity with respect to the probe pin. Therefore, iridium, which is a hard and brittle material with excellent corrosion resistance and wear resistance, There is a need to use it only at the tip contact area.

  Since iridium is a hard and brittle material, it can be easily considered that iridium is used only at the contact portion as used at the tip of the fountain pen.

  However, in the conventionally proposed probe pin, a concrete and highly feasible method for joining the iridium of the contact portion and the main body material is not proposed, and it does not go out of the mere abstract idea.

  For example, a probe pin proposed in Japanese Patent Laid-Open No. 2005-098895 is shown in FIG. In the probe pin shown in the figure, the probe 1 of the main body is made of a hardened steel wire, and a pipe-shaped gold alloy member 3 is fitted to the stepped portion 2 of the probe 1.

  A gold alloy member 5 is press-fitted inside the pipe-shaped gold alloy member 3, and an iridium member 6 is welded and fixed to the tip of the gold alloy member 5.

  However, according to the experience of the inventors, iridium, which is a platinum-based noble metal, has poor affinity with a gold alloy, and it is difficult to weld and fix iridium to the gold alloy. Furthermore, the tip of the probe pin is fine, and it is questionable in productivity to fix by welding in terms of accuracy and reliability.

  Further, even in the claims of Japanese Patent Application Laid-Open No. 2005-098895, there is no specific provision in the fixing method of iridium and a gold alloy, and it is easily assumed from known information that iridium is used at the tip of a fountain pen. Not out of idea.

  Next, a probe pin proposed in Utility Model Registration No. 3025108 is shown in FIG. In the figure, the probe 100 includes a main body portion 110 made of tungsten or beryllium copper and a contact portion 120 made of iridium.

  In the main body 110, a straight portion 112 ahead of the bent portion 111 is joined to the contact portion 120 by spot welding 130.

  However, according to the experience of the inventors, iridium has poor affinity with different metals and is difficult to join by spot welding.

  In addition, the probe pin before bending is required to have a strict straightness accuracy for the convenience of production, such as tapering of the tip and incorporation into a probe card. The structure of the probe pin is not practically usable at all.

  Furthermore, in recent probe cards for semiconductor inspection, the interval between adjacent probe pins is narrow, and probe pins having a structure that occupies a large space as shown in FIG. 5 are out of the question.

  In spite of the above practical problems, the utility model registration No. 3025108 claim describes a non-specific abstract joining method in which the main body and the contact portion are electrically and mechanically connected. And not out of the realm of unrealizable ideas.

  The present invention has been made in view of the problems of the probe pins proposed in the prior art as described above. The tip contact portion of the probe pin is made of a material containing iridium as a main component, and the main body portion is bent and has elasticity. Providing a highly practical method for joining the tip contact portion and the main body when making a material with good conductivity and electrical conductivity, and having contact portion performance excellent in corrosion resistance, wear resistance, etc. An object is to realize a probe pin for a probe card that is elastic and easy to bend.

  The present invention provides a stepped shaft at one end of a probe pin mainly composed of iridium, and has an average surface roughness in the range of 0.5 to 5 microns on the surface of the stepped shaft, or copper, nickel, etc. Thin metal mainly composed of a material having excellent electrical conductivity and cold workability, such as copper or beryllium copper, after imparting both of the metal plating with good electrical conductivity or the surface roughness and the metal plating. The pipe is fitted to the stepped shaft, and the thin pipe is heated and softened so that the inner surface of the thin pipe is bitten into the surface roughness or fused to the metal plating. .

  First, the effect of applying metal plating with good electrical conductivity will be described. According to the inventors' experience, plating of iridium with nickel, copper, etc. is possible. In the plating pretreatment, the iridium surface is activated. As a result, some of the iridium atoms are replaced with the plating metal atoms at the boundary surface between the plating layer and the iridium base surface.

  The plating metal substituted with iridium atoms at the interface between the plating layer and the iridium base surface realizes a strong bond between the plating layer and the iridium base surface by a nano-level anchor effect.

  The inner diameter surface of the thin pipe fused to the plating layer having a strong bond with the iridium base surface has a strong bond with the iridium base surface, and as a result, the thin pipe is mainly composed of iridium. It is firmly connected to the stepped portion of the probe pin.

  Next, the effect of imparting surface roughness to the stepped portion will be described. Since the inner surface of the heat-thinned thin pipe bites into the surface roughness and has a macro anchor effect, the thin pipe is firmly coupled to the stepped portion of the probe pin mainly composed of iridium.

  Furthermore, in the method of joining the iridium at the tip according to the present invention and the body part such as beryllium copper or copper, it is easy to ensure the straightness accuracy as a probe pin, and does not increase the occupied volume of the probe pin. There is no hindrance to the taper processing of the tip of the pin or the incorporation of the probe pin into the probe card, and the coupling method with high productivity and reliability and high feasibility is provided.

  In addition, when the probe pin for a probe card according to the present invention is realized, the following beneficial industrial effects are brought about.

  Because iridium has excellent corrosion resistance, wear resistance, and electrical conductivity and has a low high-temperature specific resistance, probe pins with iridium applied to the tip contact area are highly reliable in electrical testing of semiconductors. As well as an economic effect of realizing a long-life probe card.

  Furthermore, in the production of probe cards, the amount of expensive iridium material used is reduced, and the cost is reduced, and the bending workability of the main body is good, so the workability of the soldering work is improved and the productivity is increased. Increase.

Embodiments of the present invention will be described in detail below with reference to the drawings.
Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1, 2, and 3.

First embodiment

Details of the first embodiment according to the present invention will be described with reference to FIG.
In FIG. 1, a probe card probe pin 21 is composed of a probe pin 22 containing iridium as a main component and a thin pipe 26. The probe pin 22 containing iridium as a main component includes a conical portion 23, a cylindrical portion 24, and a stepped portion 25.

  Whether the outer peripheral surface of the stepped shaft portion 25 is given an average surface roughness in the range of 0.5 to 5 microns, or is metal plating with good electrical conductivity such as copper or nickel applied? Or both the surface roughness and the metal plating are applied.

  The outer diameter dimension of the cylindrical portion 25 is equal to the outer diameter dimension of the thin-walled pipe 26 whose main component is a material excellent in electrical conductivity and cold workability such as copper or beryllium copper. The outer diameter of the attached shaft portion 25 is set to an interference fit tolerance that is equal to or slightly larger than the inner diameter of the thin pipe 26.

  After fitting the thin-walled pipe 26 to the stepped portion 25, the probe card probe pin 21 is subjected to the rolling process shown in FIG. 3 immediately after being softened by heating, or while being softened by heating, Rolled.

  In FIG. 3, the slider 29 is guided to be slidable in the vertical direction by a guide member (not shown), and the table 30 is guided to be slidable in the horizontal direction by a guide member (not shown).

  A plurality of probe card probe pins 21 are stacked on the table 30 at regular intervals, and receive a vertical pressing force indicated by an arrow 32 from a slider 29.

  When the table 30 reciprocates in the direction indicated by the arrow 31, the probe card probe pin 21 sandwiched between the slider 29 and the table 30 performs reciprocating rotational movement as indicated by the arrow 33.

  When the probe card probe pin 21 heated and softened in such a state is subjected to a rolling process, the straightness accuracy of the probe card probe pin 21 is ensured, and the uniformity of the diameter is also ensured.

  Since the melting point of iridium is 2400 ° C. or more, while the melting point of copper is about 200 ° C., only the thin-walled pipe 26 can be softened to perform the rolling process.

  In the probe pin for probe card shown in the first embodiment, the tip part is made of iridium as a main component, but the rear main part is a thin pipe. Therefore, the present invention is applied to a cantilever type probe card having a small current value for inspection such as logic or memory semiconductor inspection.

Second embodiment

  If the current value of the inspection is large, or if the vertical probe has elasticity or some toughness in the main body behind the probe pin, a solid rod probe is required for the main body on the rear side. The Hereinafter, an example thereof will be described with reference to FIG.

  In FIG. 2, a probe card probe pin 21 is composed of a probe pin 22 mainly composed of iridium, a short thin-walled pipe 27, and a stepped rod 28. The probe pin 22 containing iridium as a main component includes a conical portion 23, a cylindrical portion 24, and a stepped portion 25.

  Whether the outer peripheral surface of the stepped shaft portion 25 is given an average surface roughness in the range of 0.5 to 5 microns, or is metal plating with good electrical conductivity such as copper or nickel applied? Or both the surface roughness and the metal plating are applied.

  The outer diameter dimension of the cylindrical portion 25 is equal to the outer diameter dimension of the short thin-walled pipe 27 whose main component is a material excellent in electrical conductivity and cold workability such as copper or beryllium copper, The outer diameter dimension of the stepped shaft portion 25 is set to an interference fit tolerance dimension that is equal to or slightly larger than the inner diameter dimension of the thin-walled pipe 26.

  After the short thin pipe 27 is fitted to the stepped portion 25 and the stepped rod 28 is fitted to the short thin pipe 27, the probe card probe pin 21 is shown in FIG. The rolling process is performed while being heated or softened by heating.

These are the block diagrams of the probe pin for probe cards which shows the 1st Example of this invention. These are the block diagrams of the probe pin for probe cards which shows the 2nd Example of this invention. These are explanatory drawings which give a rolling process after heating the probe pin for probe cards of this invention. These are the block diagrams of the probe pin for demonstrating a prior art. These are the block diagrams of the probe pin for demonstrating a prior art.

21 Probe pin for probe card 22 Probe pin mainly composed of iridium 23 Conical portion 24 Cylindrical portion 25 Stepped portion 26 Thin-walled pipe 27 Short thin-walled pipe 28 Stepped rod 29 Slider 30 Table 31 Arrow 32 Arrow 33 Arrow

Claims (1)

  A stepped shaft is provided at one end of a probe pin mainly composed of iridium, and the surface of the stepped shaft is given an average surface roughness in the range of 0.5 to 5 microns, or copper, nickel, etc. The main component is a material with excellent electrical conductivity and cold workability, such as copper or beryllium copper, after applying a metal plating with good electrical conductivity or providing both the surface roughness and the metal plating. The thin pipe is fitted to the stepped shaft, and the thin pipe is heated and softened so that the inner surface of the thin pipe is bitten into the surface roughness or fused to the metal plating. The probe pin for the characteristic probe card.

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