JP2012112681A - Contact probe pin and inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contact probe pin that forms a carbon coating having electric conductivity and durability on a substrate whose tip is divided and that is capable of reducing Sn deposition as much as possible even under conditions where temperature is high in usage environment and keeping electric contact stable over a long period of time, and a useful inspection method with the contact probe pin.SOLUTION: In a contact probe pin where a tip is divided into two or more protrusions and the protrusions repeatedly contact a surface to be inspected, a carbon coating containing a metal and/or a carbide thereof is formed at least on surfaces of the protrusions, respective apexes of the protrusions include flat surfaces in a direction substantially vertical to a direction contacting the surface to be inspected, and a total area of the flat surfaces is 500 μmor more and 5000 μmor less.

Description

  The present invention relates to a contact probe pin having a shape in which a tip is divided into a plurality of protrusions, and an inspection method using the contact probe pin, which are used for inspecting electrical characteristics of a semiconductor element, and in particular, repeated inspection. It is related with the contact probe pin excellent in durability so that electroconductivity does not deteriorate by this, and the test | inspection method.

  Electronic components such as integrated circuits (ICs), large-scale integrated circuits (LSIs), and light-emitting diodes (LEDs) (that is, electronic components using semiconductor elements) have their electrical characteristics brought into contact with the electrodes of the semiconductor elements by probe pins. Is inspected. The probe pin (contact probe pin) used in such an inspection apparatus (semiconductor inspection apparatus) has not only good conductivity (low contact resistance value) but also the surface of the electrode (covered) to be inspected. It is required to show a stable resistance value (the contact resistance value does not fluctuate) even by repeated contact with the surface.

  The contact resistance value of the contact probe pin is generally set to about 100 mΩ or less. However, it may deteriorate from several hundred mΩ to several Ω by repeatedly inspecting the surface to be measured.

  Conventionally, contact terminals have been regularly cleaned and replaced as countermeasures, but these may significantly reduce the reliability and availability of the inspection process, so other countermeasures are being considered. . In particular, solder materials and Sn-plated electrodes have a characteristic that they are scraped off because they are soft and easily adhere to the surface of the contact terminal, and because the surface is easily oxidized, the resistance becomes high and the contact is maintained while maintaining a stable resistance value. It becomes difficult to let you.

  The shape of the contact probe pin for the metal that forms a highly resistant oxide film on the surface, such as solder material (for example, lead-free solder such as SnAgCu alloy) or Sn plating electrode, is more They tend to be sharp and are developed based on these trends. This is because it is considered that it is advantageous to have a sharp tip in order to efficiently remove the oxide film of the counter electrode in contact and maintain a good contact state. It is also considered that even if the electrode material adheres in a sharp shape (hereinafter, sometimes represented by “Sn adhesion”), the exclusion force is likely to work.

  As such a technique, for example, in Patent Document 1, the tip is sharpened by a special manufacturing method, and the surface coating with a film containing carbon reduces Sn adhesion and efficiently removes the counter electrode surface oxide film. A technology to be realized has been proposed. Further, Patent Document 2 proposes a technique for cutting a non-conductive layer of a mating electrode with a sharp tip structure to prevent accumulation of particles scraped from the mating electrode on the tip of the contact probe pin. Thus, it is useful to make the tip of the contact probe pin sharp from the viewpoint of efficiently removing the oxide film of the counterpart electrode and preventing the accumulation of particles scraped from the counterpart electrode. It is a form.

  As a material for the contact probe pin, a material obtained by plating Au, Pd or the like on the surface of a base material such as tungsten (W) or beryllium copper (Be-Cu) having high hardness has been used. However, in contact probe pins made of these materials, electrode materials (particularly Sn) from materials such as solder materials and Sn plating are likely to adhere to the tips of the contact probe pins, and the attached electrode materials are surface oxidized. For this reason, there is a problem that the contact resistance value due to the contact probe pin becomes unstable.

  As a method to reduce the above problems caused by Sn adhesion and stabilize the contact resistance value, we also propose a technique for coating a carbon film near the tip of the contact probe pin (the tip contacting the electrode and its vicinity). (For example, Patent Documents 3 to 6). In these techniques, an alloy element such as tungsten (W) is mixed into a carbon film typified by diamond-like carbon (DLC) to the test surface (counter electrode) of the carbon film. It is an important requirement to provide a surface film that has both low adhesion and high conductivity due to the action of the mixed metal (or its carbide).

  On the other hand, a ball grid array (BGA) package is widely used as a semiconductor element mounting technology. In such a BGA package, the electrodes are in the form of half-ball solder. In addition, mounting forms in which solder is directly formed on a semiconductor wafer are increasing. With respect to these three-dimensional electrodes, stable contact can be realized by having two or more projections (particularly, three or more projections). In addition, even with a flat surface like an electrode of a conventional electronic component, it has a plurality of vertices (the tops of the protrusions), so that it can cope with misalignment or unexpected particle bites. It has a function.

JP 2006-38641 A JP 2010-73698 A Japanese Patent Laid-Open No. 10-226874 JP 2002-318247 A JP 2003-231203 A JP 2007-24613 A

  The technique of coating a carbon film near the tip of a contact probe pin is considered to be useful as a method for reducing problems due to Sn adhesion and stabilizing the contact resistance value. However, even when the carbon film is coated, there is a problem in that Sn adhesion may occur on the carbon film under conditions where the electronic component is heated, that is, under conditions where the contacted partner electrode is heated. is there.

  The carbon film does not react with Sn or the like, and an alloy is not formed on the surface of the carbon film even if Sn becomes high temperature. For this reason, compared with the conventional contact probe pin of Au or Pd alloy, it was said that the contact probe pin formed with the carbon film tends to be hard to adhere to the surface. Further, it has been considered that Sn adhering to the surface of the carbon film is relatively easy to remove mechanically and chemically, and that there is no problem. However, Sn that hardly adheres at room temperature tends to increase under high temperature conditions of 90 ° C. and 130 ° C., and problems due to Sn attachment may become apparent.

  Sn and solder materials are originally soft even at room temperature, and there is a problem that they are scraped off by contact with the contact probe pins and adhere to the contact probe pins. However, the hardness is further lowered at a high temperature, and this tendency is increased. This is considered to be the reason why Sn deposition proceeds. According to what the present inventors have confirmed through experiments, Sn is Vickers hardness: 8.9 Hv at room temperature (25 ° C.), but when it reaches 85 ° C., it decreases to Vickers hardness: 6.8 Hv. It turns out. The hardness of the Sn film is a value obtained by converting the value measured by the nanoindentation method (Vickers hardness: 8.9 Hv and 6.8 Hv are 0.117 GPa and 0.089 GPa by the nanoindentation method, respectively. Equivalent).

  The present invention has been made paying attention to the above-mentioned circumstances, and the purpose thereof is a contact that forms a carbon film having both conductivity and durability on a substrate whose tip is divided. In the probe pin, a contact probe pin and a contact probe pin that can reduce Sn adhesion as much as possible and maintain stable electrical contact for a long period of time even under conditions where the usage environment becomes high temperature are used. It is to provide a useful inspection method.

The contact probe pin of the present invention capable of solving the above-mentioned problem is that the tip is divided into two or more protrusions, and the protrusions are for repeatedly contacting the surface to be measured, and at least on the surface of the protrusions A carbon film containing a metal and / or a carbide thereof is formed, and each top portion of the protrusion is a flat surface substantially perpendicular to a direction in contact with the test surface, and the total of the flat surfaces. area of 500 [mu] m ² or more, has the gist to the point at 5000 .mu.m ² or less. The “substantially vertical direction” basically means the vertical direction, but means that it may be inclined to about 20 ° with respect to this vertical direction.

  In the contact probe pin of the present invention, it is preferable that the shape of the side surface is adjusted so that the flat surface forms an obtuse angle with the side surface of the contact probe pin. The term “obtuse angle” means that the angle θ formed by the tangent of the flat surface and the tangent of the side surface of the contact probe pin is an obtuse angle (90 ° <θ <180 °) in the cross section including the axis of the contact probe pin. ). However, the said tangent means the tangent obtained in the range within 0.1 mm from the intersection of the said flat surface and the said side surface.

  Whichever configuration is employed, the metal is preferably at least one selected from the group consisting of W, Ta, Mo, Nb, Ti, and Cr. Moreover, it is preferable that content of the said metal and / or its carbide | carbonized_material is 5-30 atomic%. Further, the thickness of the carbon film is preferably 0.1 to 5 μm.

  The effect of the contact probe pin of the present invention is effectively exhibited when the test surface to be inspected is made of Sn or Sn alloy.

On the other hand, the inspection method of the present invention capable of achieving the above object is to use a contact probe pin whose tip is divided into two or more protrusions, and inspecting the protrusions repeatedly contacting the surface to be inspected. In addition, a carbon film containing a metal and / or a carbide thereof is formed at least on the surface of the protrusion, and each top portion of the protrusion is a flat surface substantially perpendicular to the direction in contact with the test surface. And the flat surface is in contact with the surface to be inspected at a pressure of 10 N / mm ² or more and 1000 N / mm ² or less.

In the present invention, a carbon film containing a metal and / or a carbide thereof is formed on the surface of the protrusion whose tip is divided into two or more, and each top portion of the protrusion is in a direction in contact with the test surface. converting mechanism having a flat surface substantially perpendicular direction, the total area of the flat surface is 500 [mu] m ² or more, or constitute a contact probe pin as is 5000 .mu.m ² or less, or flat surface 10 N / mm ² or more, 1000 N / mm ² Since the test surface is contacted at the following pressures, the adhesion of Sn, etc. can be reduced as much as possible even under conditions where the usage environment is high, and stable electrical contact can be maintained over a long period of time. I was able to.

It is a schematic explanatory drawing which shows an example of the external appearance shape of the contact probe pin (Example) of this invention. It is the schematic explanatory drawing which showed typically the condition which the contact probe pin of this invention contacts a ball-shaped electrode. It is a graph which shows the change of an electrical resistance value when using the contact probe pin of this invention. It is a graph which shows the change of an electrical resistance value when the contact probe pin of the comparative example 1 is used. It is a graph which shows the change of an electrical resistance value when the contact probe pin of the comparative example 2 is used.

  As a configuration of the contact probe pin, there is a tendency to make the shape of the tip portion sharper, and it has been developed based on such a tendency. This is because it is considered that it is advantageous to have a sharp tip in order to efficiently remove the oxide film of the counter electrode in contact and maintain a good contact state.

  Although contact probe pins having a flat surface at the tip are known, they are often used exclusively to ensure a stable contact area and are limited to those for stable counterpart electrodes such as Au electrodes. Therefore, it is considered disadvantageous when the counter electrode is made of solder material, Sn or the like. Further, contact probe pins having a flat surface at the tip are limited to those having only one contact point (that is, having no plurality of protrusions), and having a plurality of protrusions (of this shape) Is generally called “crown shape”), which has a sharp tip.

The present inventors, without being bound by the existing concept as described above, in a contact probe pin whose tip is divided into a plurality of protrusions, a form that can reduce Sn adhesion to the carbon film formed on the top of the protrusion as much as possible, We examined from various angles. As a result, a carbon film containing a metal and / or a carbide thereof is formed on the surface of the protrusion, and each top portion of the protrusion is a flat surface substantially perpendicular to the direction in contact with the test surface. with some, the total area of the flat surface 500 [mu] m ² or more, if as is 5000 .mu.m ² or less, even under such as use environment is a high temperature situations, as much as possible can reduce the adhesion of the Sn or the like, over a long period of time The present inventors have found that a contact probe pin capable of maintaining stable electrical contact can be realized, and the present invention has been completed.

  FIG. 1 is a schematic explanatory view showing an example of the external shape of a contact probe pin (Example) according to the present invention. The contact probe pin 1 has a tip divided into four protrusions 2, and the top of each protrusion 2 is a flat surface 3 that is substantially perpendicular to the direction in contact with the surface to be examined. In this contact probe pin 1, the flat surface 3 of each protrusion 2 has a substantially fan shape (two sides are straight and one side is an arc) as shown in the figure. Each flat surface 3 is basically located on the same plane when the projections 2 have three or more. Further, the protrusion 2 becomes thinner toward the tip, and in this embodiment, the outer surface is substantially upright and the inner surface is inclined.

  In the contact probe pin of the present invention, the combination of the formation of the carbon film and the flat surface as described above can stably reduce the Sn adhesion even under the circumstances where the Sn adhesion is likely to occur at a high temperature, and the Sn-based electrode. As a result, it was possible to continuously achieve stable contact while efficiently removing the surface oxide film.

  The mechanism of Sn adhesion reduction due to the formation of a carbon film and the presence of a flat surface is not clear, but can be considered as follows. In a typical crown-shaped contact probe pin, a contact mark having a depth of about 5 to 20 μm is often formed on a solder material or Sn. That is, in a typical crown-shaped contact probe pin with a sharp tip, a contact mark larger than the tip shape may occur, and the slope is almost perpendicular to the flat part or the gentle slope part of the probe. The contact with the opponent material at is repeated.

  In such a place, contact is made such that the counterpart electrode is strongly rubbed in the lateral direction against the film surface, and Sn is scraped off by slight unevenness (from the base material) on the film surface, and there is a high possibility of transfer. It is considered to be. In the case of a probe with a sharp tip, the conditions differ from the flat part when mechanically cutting the substrate or forming a thin film (including Ni, Au, and carbon film) on the substrate. There is a possibility that slight unevenness may increase due to changes in wrinkles and film quality, and it is considered that Sn adhesion increases.

  On the other hand, unlike the contact probe pin of the present invention, since the top of the protrusion is a flat surface, it is not rubbed unnecessarily against the counterpart electrode. In addition, since the substrate can form a flat surface by a simple cutting process without forming a complicated curved surface, and the ease of forming a thin film (carbon film) on this flat surface, The existence itself can be reduced. If a predetermined amount of such a flat surface is present and a carbon film is formed on the surface, adhesion of the mating electrode material (especially Sn) can be prevented. Further, stable contact can be realized by bringing the surface of the counterpart electrode from which the oxide film is removed into contact with such a portion, that is, contacting the deformed electrode after deforming it. In addition, low cost can be realized due to the ease of manufacture.

  Such an effect can be exhibited not only in the case where the counterpart electrode has a flat surface but also in an electrode having a spherical surface, such as a half-ball-shaped electrode such as a BGA package. FIG. 2 (schematic explanatory diagram) schematically shows the situation of contact with the ball-shaped electrode. The ball-shaped electrode has a flat surface perpendicular to the direction in which the contact probe 1 is brought into contact. In this case, a shape in which the tip of the entire probe is narrowed first is preferable so that the flat surface can easily come into contact with the ball.

  The contact probe pin 1 of the present invention preferably has a configuration in which the shape of the side surface is adjusted so that the flat surface 3 forms an obtuse angle with the side surface 4 of the contact probe pin 1 (see FIG. 1). The presence of such a portion makes it possible to stabilize the contact between the probe and the counterpart electrode and reduce the attachment of the counterpart electrode material to the side surface of the probe as much as possible. By pressing the flat surface, the deformed Sn or Sn alloy including the surface oxide film is efficiently removed from the contact surface, and a good contact surface can be formed. Moreover, the loss more than necessary on the electrode side can be reduced. The side surface 4 of the contact probe pin forms a continuous surface with the side surface (outer surface) of the protrusion 2.

  Further, from the viewpoint of durability improvement and quality stability, a curved surface R is formed by rounding the boundary portion 5 (see FIG. 1) between the flat surface 3 and the side surface 4 of the contact probe pin 1 (see FIG. 1). Is also effective. Formation of such a part can be easily achieved by increasing the thickness of the carbon film formed on the surface, etching etching treatment with a chemical agent, or the like.

In order to exhibit the above effects, the total area on the top flat surface needs to be 500 to 5000 μm ² . Preferably 800 [mu] m ² or more and 3000 .mu.m ² or less. If this total area is less than 500 μm ^2, the area of the flat surface for reducing Sn adhesion is not sufficient, and the area where Sn adhesion increases due to repeated contact is large, so that stable contact is difficult to obtain. On the other hand, if the total area exceeds 5000 μm ² , the oxide film on the electrode surface cannot be sufficiently removed, and the resistance tends to be high.

  The contact probe pin of the present invention is configured by forming a carbon film containing a metal and / or a carbide thereof on the surface of the substrate (surface near the tip). As the substrate to be used, for example, a beryllium alloy One made of either (Be—Cu) or carbon tool steel can be applied. However, it is not limited to these. In addition, it is also known that the base material is formed with a noble metal such as Au, Pd, Au alloy or Pd alloy on the surface or in contact with the electrode. Either can be applied. Alternatively, the base material itself may be made of Au, Pd, Au alloy, Pd alloy, or the like.

  Since the carbon film has low reactivity with respect to the above various base materials and is hard and has a large internal stress, it is difficult to stably form the carbon film on the base material. From these facts, it is also known that it is effective to interpose a layer containing Cr or W between the two in order to enhance the adhesion between the base material and the carbon film, and to further provide a gradient composition layer as necessary. However, this configuration can also be adopted. In order to further improve the adhesion between the layer containing Cr and W and the surface of the base material, a layer made of Ni or Ni alloy is further interposed as an underlayer of the layer containing Cr or W as described above. It is preferable because the carbon film can be stably adhered on the surface of the base material made of Au, Pd, or the like.

  As a method for forming a carbon film on the substrate surface of the contact probe pin, a CVD method (chemical vapor deposition method), a sputtering method, or the like can be applied. Among these, in the CVD method, since a material containing hydrogen is used as a raw material gas, hydrogen is contained in the carbon film, and only a low carbon film can be formed. On the other hand, it is preferable to apply a sputtering method because a carbon film having good characteristics can be formed.

  When the metal contained in the carbon film is a metal that easily forms a carbide, it is uniformly dispersed in the carbon film and kept in an amorphous and uniform state. From this point of view, examples of the metal contained in the carbon film include tungsten (W), tantalum (Ta), molybdenum (Mo), niobium (Nb), titanium (Ti), and chromium (Cr). One or more metals can be used. Of these, tungsten is most preferable in consideration of the stability of carbides and availability at low cost.

  The metal contained in the carbon film is in the form of a single metal or a carbide (or a mixed state) based on the manufacturing principle, and the electric resistance value of the carbon film is determined by the content. The carbon film formed with the contact probe pin of the present invention exhibits the above characteristics, and the value satisfies the contact resistance value and hardness required at the time of inspection. From the viewpoint of satisfying the above characteristics, the metal and / or carbide content in the carbon film at the tip of the contact probe pin is preferably about 5 to 30 atomic%.

  In the contact probe pin of the present invention, if the thickness of the carbon film is too thin, the effect of forming the carbon film is not exhibited. However, if the thickness of the carbon film is too thick, the resistance value increases, and therefore it is preferably 5 μm or less. The thickness of the carbon film is more preferably 0.2 μm or more, and more preferably 2 μm or less.

  The surface to be inspected (contact electrode) to be inspected by the contact probe pin of the present invention usually uses solder, which basically contains Sn, and this Sn particularly adheres to the surface of the contact probe pin. It is easy. Therefore, when the test surface is made of Sn or an Sn alloy, the effect is particularly effectively exhibited when the contact probe pin of the present invention is applied.

  By the way, in the inspection with the contact probe pin, it is common to apply a load of several grams to several tens of grams at the time of contact, more specifically, about 5 to 50 g, but this corresponds to the hardness of the mating electrode material at this time. Thus, the angle at which the electrode is deformed and finally comes into contact is determined. The inventors of the present invention divided the tip into two or more protrusions, and formed a carbon film containing a metal and / or a carbide thereof at least on the surface of the protrusions. When a load of about 5 to 40 g is applied using a contact probe pin that is a flat surface substantially perpendicular to the contact direction, the pressure (pressure per unit area of the flat surface) and the durability of the contact probe We also examined the relationship between

As a result, if the flat surface is inspected by contacting with the test surface at a pressure of 10 N / mm ² or more and 1000 N / mm ² or less, the contact probe pin itself or the counterpart electrode is reduced while reducing Sn adhesion as much as possible. It has also been found that good electrical contact can be realized stably without mechanical breakage. In order to exert such an effect, the pressure when contacting the flat surface needs to be 10 N / mm ² or more and 1000 N / mm ² or less per area of the flat surface. If this pressure is less than 10 N / mm ² , electrical contact cannot be sufficiently achieved especially when a highly resistant carbon film is on the surface, resulting in high resistance. If it exceeds 1000 N / mm ² , both the electrode and the probe are excessively pressurized. Damage can be significant and promotes extra Sn adhesion, which in turn results in a stable contact material. Preferably, it is about 50 to 800 N / mm ² .

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, but may be appropriately modified within a range that can meet the purpose described above and below. Of course, it is possible to implement them, and they are all included in the technical scope of the present invention.

In the contact probe pin, as shown in FIG. 1 (schematic explanatory diagram showing an example of the external shape), a probe with a built-in spring whose tip is divided into four protrusions and the total area of the flat part at the top of the protrusion is about 2000 μm ^2. Was made. The total diameter of the tip is 0.3 mm (300 μm). This contact probe pin has a surface plated with Au, and the substrate 1 is made of Be-Cu (commercially available). Due to the function of the spring, a load of 30 gf (147 N / mm ² ) is generated when the electrode contacts with the counter electrode and is pushed in through a predetermined stroke.

Each of a carbon (graphite) target, a Cr target, and a Ni target was placed in a magnetron sputtering apparatus, and a contact probe pin (base material) was placed at a position facing them. The sputtering chamber was evacuated to 6.7 × 10 ⁻⁴ Pa or less, and Ar gas was introduced to adjust the pressure to 0.13 Pa. After applying Ar ion etching by applying a high-frequency voltage to the base material, Ni is formed by stacking 50 nm and Cr with a thickness of 50 nm as an adhesion layer with the base material, and further a carbon film containing Cr and W The intermediate layer of the gradient composition layer that gradually increases the ratio of the carbon film is formed (thickness: 100 nm), and finally, the input power density is formed when the outermost carbon film is formed. A graphite target with a W chip mounted at 5.66 W / cm ² was subjected to DC magnetron discharge, a bias voltage of −100 V was applied to the substrate, and coating was performed to a thickness of about 400 nm (0.4 μm). At this time, it adjusted so that content of W of the outermost surface of a carbon film might be 5-10 atomic%.

Using the formed contact probe pin with carbon film (contact probe pin of the present invention), a sample of lead full solder (made by Senju Metal) having a composition of SnAg _3.0 Cu _0.5 was processed at a temperature of 130 ° C. Contact was made 10,000 times, and the Sn adhesion state of the tip (projection) was observed. Moreover, in order to confirm the presence or absence of the stability of an electrical resistance value, electricity supply of 100 mA was implemented for every contact, and the change (resistance value fluctuation | variation) of the electrical resistance value was calculated | required. However, the resistance was measured once every 100 times.

  At this time, for comparison, (A) the same as the above except that the protrusion at the tip is sharp and has no flat surface, and a carbon film is formed on a probe that generates a load of 25 gf at a predetermined stroke. A contact probe pin with carbon coating (Comparative Example 1) and (B) the same probe as Comparative Example 1 (Comparative Example 2) were prepared. With respect to these contact probe pins, the state of the tip after contact was observed in the same manner as described above, and the presence or absence of stability of the electrical resistance value was investigated.

  FIG. 3 shows changes in the electrical resistance value (relationship between the number of contacts and fluctuations in the electrical resistance value) when the contact probe pin (Example) of the present invention is used. FIG. 4 shows changes in electrical resistance values (relationship between the number of contacts and fluctuations in electrical resistance values) when the contact probe pins of Comparative Example 1 are used. FIG. 5 shows changes in electrical resistance values (relationship between the number of contacts and fluctuations in electrical resistance values) when the contact probe pins of Comparative Example 2 are used.

  These results can be considered as follows. First, it can be seen that the contact probe pin (Example) of the present invention maintains an electrical resistance value substantially equal to the initial value even after 100,000 contacts (FIG. 3). The contact probe pin of Comparative Example 1 shows a tendency that the resistance gradually increases although the fluctuation of the electric resistance value is small (FIG. 4). Assuming that the allowable value of the fluctuation of the electric resistance value is 200 mΩ, the contact probe pin of the present invention is 70,000 times or more, and the contact probe pin of Comparative Example 1 is additional about 20,000 times. It can be seen that a stable connection is possible without performing work.

  On the other hand, in the contact probe pin of Comparative Example 2 in which no carbon film is formed, an increase in the electrical resistance value is recognized early after contact due to a large amount of Sn adhesion (FIG. 5). For this reason, the resistance transition up to 10,000 times in the initial stage is shown in FIG.

For each contact probe pin, the following results were obtained for the state of the tip. First, the contact probe pin (Example) of the present invention has an effective contact area of 500 μm ² or more (the original flat surface surface is exposed) even after 100,000 contacts. There was found.

The contact probe pin of Comparative Example 1 retains an effective contact area of 500 μm ² or more after 10,000 contacts, but most of the flat surface after 100,000 contacts. , And was covered with the deposited Sn compound. Furthermore, in the contact probe pin of Comparative Example 2, most of the flat surface was covered with the deposited Sn compound until 10,000 times of contact.

Note that hit the the evaluation as described above, to that the reference and 500 [mu] m ^2, if the contact area of 500 [mu] m ² is ensured, and a high carbon film electrical resistance than the metal is formed This is because the resistance of the contact portion can be generally kept at a low value of 10 mΩ or less even in the case of being present.

1 Contact probe pin 2 Protrusion 3 Flat surface 4 Side surface 5 Boundary portion

Claims (7)

The tip is divided into two or more protrusions, and the protrusions are for repeatedly contacting the test surface, and at least the surface of the protrusions is formed with a carbon film containing a metal and / or a carbide thereof. and, the top of said protrusions, and characterized in that with a flat surface substantially perpendicular to the direction in contact with the test surface, the total area of the flat surface 500 [mu] m ² or more and 5000 .mu.m ² or less Contact probe pin to be used.   The contact probe pin according to claim 1, wherein the shape of the side surface is adjusted such that the flat surface forms an obtuse angle with the side surface of the contact probe pin.   The contact probe pin according to claim 1, wherein the metal is at least one selected from the group consisting of W, Ta, Mo, Nb, Ti, and Cr.   The contact probe pin according to claim 1, wherein a content of the metal and / or carbide thereof is 5 to 30 atomic%.   The contact probe pin according to claim 1, wherein the carbon film has a thickness of 0.1 to 5 μm.   The contact probe pin according to claim 1, wherein the test surface to be inspected is made of Sn or an Sn alloy. When a contact probe pin whose tip is divided into two or more protrusions is used and the protrusion is repeatedly brought into contact with the surface to be inspected, at least the surface of the protrusion contains a metal and / or a carbide thereof. A carbon film is formed, and a flat surface substantially perpendicular to the direction in contact with the test surface is formed on each top of the protrusion, and the flat surface is 10 N / mm ² or more and 1000 N An inspection method comprising inspecting the surface to be inspected with a pressure of / mm ² or less.

Images