JP2007322369A - Contact probe and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a form capable of efficiently manufacturing a contact probe of a type for obtaining contact pressure to a material brought into contact for measuring electric characteristics by bending with load applied to both ends, and to provide its manufacturing method. <P>SOLUTION: On the contact probe having an insulative coat around an outer periphery of a pin-shaped metallic conductor, (1) a shape of one or both ends of the probe 1 comprises worked end surfaces 2a and 2b of the metallic conductor 2 and worked end surfaces 3a and 3b of the coat 3, and the shape of the end is one selected from a hemispherical form, a conic form, a conic form having a hemispherical form at the tip and a conic form having a flat form at the tip; and/or (2) one or both ends of the probe 1 are formed of the worked end surfaces 2a and 2b of the metallic conductor 2 with the tip exposed by grinding and the worked end surfaces 3a and 3b of the insulative coat 3 ground concurrently with the worked end surfaces 2a and 2b of the metallic conductor 2 and consisting of a form along the forms of the end surfaces 2a and 2b of the conductor 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a contact probe for inspection mainly used for continuity inspection of electronic components and substrates, and more particularly to a manufacturing method thereof. More specifically, the present invention relates to obtaining a contact pressure with respect to a contacted object by applying a weight to both ends. The present invention relates to a shape of a contact probe that can efficiently manufacture a contact probe that measures electrical characteristics, and a manufacturing method thereof.

  In recent years, various circuit boards such as high-density mounting boards used for mobile phones and the like, IC package boards such as BGA (Ball Grid Array) and CSP (Chip Size Package) incorporated in personal computers, etc., are often used. Yes. Such a circuit board is subjected to, for example, a measurement of a direct current resistance value or a continuity test in the processes before and after mounting, and the electrical characteristics of the circuit board are inspected. The inspection of electrical characteristics is performed using an inspection apparatus jig (hereinafter referred to as “probe unit”) connected to an inspection apparatus for measuring electrical characteristics. For example, a pin shape mounted on the probe unit is used. The probe (referred to as “contact probe” in this application) is brought into contact with the electrode (hereinafter also referred to as “measurement object”) of the circuit board (see, for example, Patent Document 1). .

  FIG. 8 is a schematic cross-sectional view showing an example of a conventional contact probe, and FIG. 9 is a schematic cross-sectional view for explaining a method for inspecting the electrical characteristics of a measurement object using a probe unit including a conventional contact probe. FIG. In the contact probe 101 shown in FIG. 8, a linear metal conductor 102 having a spring property is coated with an insulating film 103, and the insulating film at both ends is peeled off to expose the metal conductor 102. Both ends of the contact probe 101 have both ends composed of a front end 102a that contacts the electrode 112 of the measured object 111 and a rear end 102b that contacts the lead wire 150 on the inspection apparatus side (see FIG. 9). In such a contact probe 101, (1) after both ends of a metal conductor 102 cut to a predetermined length are ground into a predetermined shape, an insulating paint is spray-coated in a state where a predetermined region including both ends is masked. Manufactured or (2) A metal conductor with an insulating coating that is continuously baked and enameled on a long metal conductor is cut to a predetermined length, and an insulating coating in a predetermined region including both ends is laser-peeled or mechanically peeled off It is manufactured by grinding both ends after removing by.

  The probe unit 110 shown in FIG. 9 includes a plurality of to several thousand contact probes 101, a guide plate 130 with a guide hole that guides the lead wire side of the contact probes 101, and the tip of the contact probe 101 is the object 111 to be measured. At least a guide plate 120 with a guide hole for guiding the electrode side of the contact probe 101 so as to contact the electrode 112 is provided. In the inspection of the electrical characteristics, the probe unit 110 or the measured object 111 is relatively moved up and down, and the contact probe 101 is pressed against the electrode 112 of the measured object 111 with a predetermined pressure using the elastic force of the contact probe 101. Is done. At this time, the rear end 102b of the contact probe 101 bent by the force pressed against the electrode 112 strongly contacts the lead wire 150, and an electrical signal from the measured object 112 passes through the lead wire 150 and is inspected (shown). Not sent.)

  Note that, as a form example when inspecting the electrical characteristics of the measurement object 111, the form shown in FIG. 9 is upside down, and the tip 102a of the contact probe 101 presses against the downward electrode 112 from below. In some cases, the probe unit 110 and the measured object 111 may be positioned while the contact probe 101 and the lead wire 150 are kept in contact with each other. In FIG. 9, reference numeral 140 denotes a lead wire holding plate.

Setting of the contact probe 101 to the probe unit 110 is normally performed by inserting the contact probe 101 from a guide hole provided in the guide plate 130. Therefore, the guide hole is formed with a diameter larger than the diameter of the contact probe 101 covered with the insulating film.
JP 2002-131334 A

  However, in the manufacturing method in which insulating coating is spray-coated after masking on a metal conductor of a predetermined length, it is manufactured through at least cutting, grinding, masking, and coating, while cutting long metal conductors with insulating coatings. After that, the method of peeling off the insulating coatings at both ends is manufactured through at least enamel baking, cutting, peeling, and grinding, and each of the manufacturing methods has a large number of processing steps and causes a cost increase.

  Further, as shown in FIG. 9, the clearance between the guide hole of the guide plate 130 on the lead wire side and the end portion 102b on the lead wire side of the contact probe 101 is large, and the centering of the end portion 102b of the metal conductor 102 is sufficient. However, the contact between the end portion 102b and the lead wire 150 becomes unstable.

  Further, when the probe unit 110 shown in FIG. 9 is configured upside down and the electrode 112 of the measured object 111 is formed of a solder bump, the probe unit 110 is raised and the contact probe 101 is pushed against the electrode 112. When the contact is made, the tip of the contact probe 101 and the electrode 112 may adhere to each other so that the electrode 112 sticks, and then the contact probe 101 may be separated. If such a phenomenon continues, solder powder is generated, which may cause a problem that the solder powder accumulates on the electrode-side guide plate 120 and an adjacent contact probe is short-circuited.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to use a contact that measures electrical characteristics by obtaining a contact pressure with respect to a contacted object by applying a weight to both ends to bend. An object of the present invention is to provide a shape of a contact probe that can efficiently manufacture a probe, enables stable contact, and does not cause a short-circuit problem, and a manufacturing method thereof.

  A contact probe according to a first aspect of the present invention for solving the above-described problems has an insulating coating on the outer periphery of a pin-shaped metal conductor, and contacts the object to be measured by applying a weight to both ends. In a contact probe of a type that obtains pressure and measures electrical characteristics, one or both ends of the contact probe are ground at the same time as the processed end surface of the metal conductor with the tip exposed by grinding and the processed end surface of the metal conductor. It is processed and formed with the process end surface of the insulating film which consists of a shape along the process end surface shape of the said metal conductor.

  According to the present invention, one end or both ends of the contact probe are obtained by grinding the end face of the metal conductor and the end face of the insulating coating at the same time. Therefore, the obtained contact probe is obtained by a conventional process. It can be obtained with a smaller number of processing steps than those obtained, and cost reduction can be realized.

  In addition, at one or both ends of the contact probe, since the insulating coating is covered to the vicinity of the exposed metal conductor tip, the clearance between the guide hole of the guide plate and the contact probe is small, and the end of the metal conductor is Sufficient centering can be achieved, and instability of contact between the metal conductor and the lead wire can be eliminated. Similarly, since the insulating coating is covered to the vicinity of the exposed metal conductor tip, the probe unit shown in FIG. 9 is configured upside down, and when the electrode of the object to be measured is formed of solder bumps, Even when the generated solder powder accumulates on the guide plate on the electrode side, there is no problem of shorting adjacent contact probes.

  A contact probe according to a second aspect of the present invention for solving the above-described problems has an insulating coating on the outer periphery of a pin-shaped metal conductor, and contacts the object to be measured by applying a weight to both ends. In the contact probe of the method for measuring the electrical characteristics by obtaining pressure, the shape of one end or both ends of the contact probe consists of the end face shape of the metal conductor and the end face shape of the insulating coating, and the one end The shape of the part or both ends is any one selected from a hemispherical shape, a conical shape, a conical shape having a hemispherical shape at the tip, and a conical shape having a flat shape at the tip.

  According to this invention, the shape of one end part or both end parts composed of the end face of the metal conductor and the end face of the insulating coating has a hemispherical shape, a conical shape, a conical shape having a hemispherical shape at the tip, and a flat shape at the tip. Since it is any one selected from a conical shape, the insulating coating is covered to the vicinity of the exposed metal conductor tip unlike the conventional method having many processing steps. The contact probe with such a shape has a small clearance between the guide hole of the guide plate and the contact probe, can sufficiently center the end of the metal conductor, and eliminates unstable contact between the metal conductor and the lead wire. it can. Similarly to the above, even when the generated solder powder is stored on the electrode-side guide plate, there is no problem of shorting adjacent contact probes.

  In the contact probe according to the first and second aspects of the present invention, the material of the insulating coating is at least selected from polyurethane resin, nylon resin, polyester resin, epoxy resin, polyesterimide resin, polyamide resin and polyamideimide resin. It is preferably a kind of resin.

  In order to solve the above-mentioned problems, the contact probe manufacturing method of the present invention has an insulating coating on the outer periphery of a pin-shaped metal conductor, and obtains a contact pressure with respect to the object to be measured by applying a weight to both ends. A method of manufacturing a contact probe of a method for measuring electrical characteristics by cutting a long metal conductor on which an insulating film is formed, and one or both ends of the cut metal conductor with an insulating film The end face of the metal conductor and the end face of the insulating coating are simultaneously ground to form a shape consisting of the end face of the metal conductor and the end face of the insulating coating, a hemispherical shape, a conical shape, and a conical shape having a hemispherical shape at the tip And a step of making any shape selected from a conical shape having a flat shape at the tip.

  This invention includes a step of spray-coating an insulating paint after masking on a metal conductor of a predetermined length, and a step of laser-peeling or mechanically peeling off the insulating coating at both ends after cutting a long metal conductor with an insulating coating. Since it is unnecessary, it is an efficient manufacturing method that requires less processing steps and can realize cost reduction.

  According to the contact probe of the present invention, one or both ends of the contact probe are obtained by grinding the end face of the metal conductor and the end face of the insulating coating at the same time. It can be obtained with fewer processing steps than those obtained in the process, and cost reduction can be realized. In addition, since the insulating coating is covered to the vicinity of the exposed metal conductor tip, the clearance between the guide hole of the guide plate and the contact probe is small, and the end of the metal conductor can be sufficiently centered. Unstable contact with lead wires can be eliminated. Similarly, since the insulating film is covered to the vicinity of the exposed metal conductor, this occurs when the probe unit shown in FIG. 9 is configured upside down and the electrodes of the object to be measured are formed of solder bumps. Even when the solder powder accumulates on the electrode-side guide plate, there is no problem of shorting adjacent contact probes.

  According to the method for manufacturing a contact probe of the present invention, since it is an efficient method with a small number of processing steps, a low-cost contact probe can be provided. In addition, when the tip is ground into a shape such as a hemisphere or a cone suitable for a contact probe, an insulating coating of, for example, 0.01 to 0.2 mm can be simultaneously ground and removed from the tip of the metal conductor. Thus, it is possible to reduce or halve the conventional process for removing the insulating film near both ends, and to provide a low-cost contact probe.

  Hereinafter, a contact probe and a manufacturing method thereof according to the present invention will be described with reference to the drawings. In addition, this invention is not limited to the following embodiment.

(Contact probe)
FIG. 1 is a schematic sectional view showing an example of the contact probe of the present invention, and FIG. 2 is a schematic sectional view showing another example of the contact probe of the present invention. FIG. 3 is a sectional view showing a characteristic embodiment of one or both ends of the contact probe of the present invention.

  As shown in FIGS. 1 and 2, the contact probe 1 of the present invention (hereinafter sometimes simply referred to as “probe 1”) has a pin-shaped metal conductor 2 and an insulating coating 3 on the outer periphery of the metal conductor 2. This is a probe of a type that measures the electrical characteristics by obtaining a contact pressure with respect to the object to be measured by applying a weight to both ends to bend. The features of the probe 1 are as follows: (1) The shape of one end or both ends of the probe 1 is made up of the processed end faces 2a, 2b of the metal conductor 2 and the processed end faces 3a, 3b of the insulating coating 3. The shape of the end portion is any one selected from a hemispherical shape, a conical shape, a conical shape having a hemispherical shape at the tip, and a conical shape having a flat shape at the tip, and / or (2) the probe 1 One end or both ends of the metal conductor 2 are ground at the same time as the processed end faces 2a and 2b of the metal conductor 2 with the tip exposed, and the processed end faces 2a and 2b of the metal conductor 2, and the processed end face of the metal conductor 2 is processed. It is formed by the processed end faces 3a and 3b of the insulating coating 3 having a shape along the shapes 2a and 2b.

  In FIG. 1 and FIG. 2, the processed end surface 2 a is a processed end surface of the metal conductor 2 on the “tip” side that is arranged on the measured object side and contacts the electrode 12 of the measured object 11, and the processed end surface 2 b is This is a processed end face of the metal conductor 2 on the “rear end” side that is arranged on the inspection apparatus side and contacts the lead wire 50 of the inspection apparatus (not shown). The processed end face 3a is a processed end face of the insulating coating 3 on the front end side, and the processed end face 3b is a processed end face of the insulating coating 3 on the rear end side. Further, in the present application, the “one end portion” is a one end portion having a characteristic shape of the contact probe 1 according to the present invention, for example, a region including the processing end surfaces 2b and 3b on the rear end side shown in FIG. The “both end portions” are both end portions having the characteristic shape of the contact probe 1 according to the present invention. For example, the region including the processing end surfaces 2a and 3a on the front end side shown in FIG. It refers to both of the regions including the processed end faces 2b and 3b.

  As the metal conductor 2, a metal wire (also referred to as “metal spring wire”) having high conductivity and high elastic modulus is used. Examples of the metal used for the metal conductor 2 include metals having a wide elastic range. For example, a copper alloy such as beryllium copper, tungsten, rhenium tungsten, steel (for example, high speed steel: SKH) or the like is preferably used. it can.

  The metal conductor 2 is usually subjected to plastic working such as cold or hot wire drawing until the metal becomes a linear conductor having a predetermined diameter. The outer diameter of the metal conductor 2 is arbitrarily selected from the range of 20 μm or more and 400 μm or less, preferably 25 μm or more and 200 μm or less, depending on the interval between adjacent probes 1 in the probe unit 10 (see FIGS. 6 and 7). can do.

  In addition, it is easy to attach the probe 1 to the probe unit 10 and to prevent the movement of the probe 1 from being hindered by the tip of the probe 1 being caught in the guide hole of the guide plate 20 when the probe unit 10 is used. Therefore, it is preferable that the straightness of the metal conductor 2 is high. Specifically, the straightness is preferably 1000 mm or more in terms of the radius of curvature R. The metal conductor 2 with high straightness is subjected to straightening treatment before the insulating coating 3 is provided, or by straightening the long metal conductor 2 provided with the insulating coating 3 as described later. Obtainable. The straightening process here is performed, for example, by a rotary die type straightening apparatus or the like.

  The shape of the processing end surface 2a on the front end side and / or the processing end surface 2b on the rear end side of the metal conductor 2 is a hemispherical shape shown in FIG. 3 (A), a conical shape shown in FIG. 3 (B), and a shape shown in FIG. It is any one selected from a cone shape having a hemispherical shape at the tip shown, a cone shape having a flat shape at the tip shown in FIG. The “hemispherical shape” and “conical shape” here include an accurate hemisphere and a cone, but also include a substantially cone and a substantially hemisphere. In the end face shape having such characteristics, the lengths L1 to L4 of the metal conductor 2 protruding from the front end or the rear end shown in FIG. 3 are in the range of 0.01 mm or more, 0.2 mm or less, preferably 0.1 mm or less. . When the wire diameter of the metal conductor 2 is small, the protrusion lengths L1 to L4 of the metal conductor 2 are shifted to the lower limit side, and when the wire diameter of the metal conductor 2 is large, the protrusion lengths L1 to L1 of the metal conductor 2 are shifted. L4 shifts to the upper limit side.

  In the processed end faces 2a and 2b, a plating layer is provided on the processed end faces 2a and 2b in order to suppress an increase in the contact resistance value between the metal conductor 2 and the electrode 12 of the measured object 11 or the lead wire 50 of the inspection apparatus. It may be done. Examples of the metal forming the plating layer include metals such as nickel, gold, and rhodium, and alloys such as gold alloys. The plating layer may be a single layer or a multilayer. Preferred examples of the multi-layered plating layer include those in which a gold plating layer is formed on a nickel plating layer.

  The insulating coating 3 is provided on the metal conductor 2 and acts to prevent short circuits by preventing the probes from contacting each other when inspecting the electrical characteristics of the measurement object 11. The insulating coating 3 may be provided on the metal conductor 2, that is, on the outer periphery of the metal conductor 2 in the longitudinal direction, and may be provided directly or via another layer. May be.

  The insulating film 3 is not particularly limited as long as it is an insulating film, but it is any one selected from polyurethane resin, nylon resin, polyester resin, epoxy resin, polyesterimide resin, polyamide resin and polyamideimide resin. Is preferred. Usually, it is formed of one kind of resin. Since the insulating film made of these resins has different heat resistance, it can be arbitrarily selected in consideration of the heat generated during the inspection. For example, when more heat resistance is required, the insulating coating 3 is preferably formed of a polyesterimide resin, a polyamideimide resin, or the like. The thickness of the insulating coating 3 may be a thickness that can ensure electrical insulation, and is appropriately set within a range of 1 μm to 50 μm in consideration of the relationship with the diameter of the metal conductor 2.

  In the present invention, the insulating coating 3 is preferably formed as a baked enamel coating. As will be described later, the baking enamel coating is formed in a continuous process by repeated application of coating and baking, so that the productivity is good, the adhesion between the metal conductor 2 is high, and the coating strength is higher. be able to.

  The probe 1 of the present invention has one end portion or both end portions composed of the end surface shape of the metal conductor 2 and the end surface shape of the insulating coating 3, and as shown in FIG. Alternatively, the shape of both ends is selected from a hemispherical shape, a conical shape, a conical shape having a hemispherical shape at the tip, and a conical shape having a flat shape at the tip, and / or (2) one end of the probe 1 Alternatively, both end portions are ground at the same time as the processing end surfaces 2a and 2b of the metal conductor 2 with the tip portions exposed by grinding and the processing end surfaces 2a and 2b of the metal conductor 2, and the processing end surfaces 2a and 2b of the metal conductor 2 are processed. It is formed with the process end surfaces 3a and 3b of the insulating coating 3 which has a shape along the shape of the above. As used herein, “the processed end faces 3a and 3b of the insulating coating 3 having a shape along the shape of the processed end faces 2a and 2b of the metal conductor 2” refers to the processed end faces 3a of the insulating coating 3 as shown in FIG. The shape formed by grinding simultaneously with the processing end surface 2a of the metal conductor 2.

  For example, as shown in FIG. 1, the shape of the above (1) is obtained by grinding one end or both ends of the probe 1 so that the end faces 2a, 2b of the metal conductor 2 and the end faces 3a, 3b of the insulating coating 3 are simultaneously formed. Although it is formed by grinding, other processing methods may be adopted as long as a similar shape can be expressed. The above (2) is formed by grinding the end faces 2a, 2b of the metal conductor 2 and the end faces 3a, 3b of the insulating coating 3 simultaneously by grinding. The detailed shape of one end or both ends of the probe 1 is not particularly limited, and various shape elements may be provided. For example, the curvature of the curved surface in FIGS. 3A and 3C, the angle of the inclined surface in FIGS. 3B and 3D, the area of the flat surface at the tip in FIG. 3D, etc. Various values can be arbitrarily set for the shape element.

  Examples of the grinding process include a grinding process using emery paper and a grinding process using a diamond wheel. The tip shape can be obtained by rotating the probe 1 brought into contact with a rotating emery paper or a diamond wheel at a predetermined angle (the shapes shown in FIGS. 3B and 3D), and further, emery paper or diamond. It can be obtained by changing the angle with respect to the wheel or the like (the shapes of FIGS. 3A and 3C). Moreover, as a grinding apparatus, the commercially available grinding machine which can grind a pin-shaped metal material may be used, for example, you may use the grinding apparatus of Unexamined-Japanese-Patent No. 2005-3516.

  In addition, in the probe 1 shown in FIG. 2, the code | symbol 3c has shown the end surface of the insulating film 3 located in area | regions other than the both ends (2a, 2b) of the metal conductor 2. FIG. The end face 3c is formed at a position where it abuts on the guide hole of the guide plate 20 used when measuring the electrical characteristics. When the electrical characteristics inspection using the probe unit is repeatedly performed, the end 3c is repeatedly provided in the guide hole. It hits. The end 3c acts so as to prevent the probe 1 from falling off from the guide plate 20 provided in the probe unit 10.

(Contact probe manufacturing method)
Next, a method for manufacturing the probe of the present invention will be described. FIG. 4 is a process flow chart showing an example of the probe manufacturing method of the present invention, and FIG. 5 is a process flow chart showing another example of the probe manufacturing method of the present invention. The probe manufacturing method of the present invention is a method for manufacturing the above-described probe 1 of the present invention, in which the step of cutting the long metal conductor 2 on which the insulating coating 3 is formed, and the cut metal with the insulating coating. For one end or both ends of the conductor 2, the end faces (2 a, 2 b) of the metal conductor 2 and the end faces (3 a, 3 b) of the insulating coating 3 are ground simultaneously, and the end faces (2 a, 2 b) of the metal conductor 2 The shape formed by the end faces (3a, 3b) of the insulating coating 3 is any one selected from a hemispherical shape, a conical shape, a conical shape having a hemispherical shape at the tip, and a conical shape having a flat shape at the tip. The method which has a process to do.

  The cutting step is a step of cutting the long metal conductor 2 on which the insulating coating 3 is formed to a predetermined length. In this cutting step, for example, a long-sized metal conductor having a baking enamel film formed as the insulating film 3 is formed into a predetermined length by taking into account that the end is processed using a standard cutting device or the like. Disconnect.

  The long metal conductor on which the baking enamel film provided for the cutting process is formed is repeatedly applied with an enamel paint and baking on the long metal conductor having spring properties, as already described in the description of the probe 1. It is formed by an insulating film forming process (baking enamel insulating coating process) to be performed.

  A normal enameled wire manufacturing apparatus (manufacturing line) can be used in the insulating film forming step. That is, enamel paint is applied to a linear metal conductor (hereinafter also referred to as a wire) fed from a wire feeder such as a bobbin in a paint tank, and then a paint such as a die or felt provided immediately after that. Handle the paint on the surface of the wire to a substantially uniform thickness with a drawing tool, then introduce the wire into a high-temperature baking furnace such as an electric heating furnace or hot air circulating furnace, and remove the solvent in the paint applied on the wire in the furnace. The process of volatilizing and removing the paint is reactively cured, and a cured coating layer is formed on the surface of the wire, and is derived from the baking furnace. The process of passing the derived wire through the paint tank, paint squeezing tool and baking furnace is repeated several times. After a cured coating film layer having a desired thickness is formed on the surface of the wire, the enamel coating film is continuously formed by winding it on a winding device such as a take-up bobbin by a pulling device such as a capstan.

  By using such an enameled wire manufacturing apparatus, an insulating film having a uniform film thickness can be easily formed. In the insulating coating forming process, the enamel coating and baking are usually repeated until the insulating coating has a desired average film thickness. The enamel paint is prepared by mixing the resin already described in the description of the probe and an organic solvent.

  It is desirable to increase the straightness of the metal conductor before the cutting step. As a means for that, (1) Obtain a metal conductor with high straightness and coat the enamel with the metal conductor, or (2) Straighten the metal conductor and use the metal conductor with the enamel coating. Or (3) a straight work in which straightening is performed after the enamel coating is applied to the metal conductor. Straightening can be performed by current annealing while applying axial tension to a long metal conductor. In addition, as a metal conductor with an insulation film with high straightness, the material which concerns on the patent (patent 3415442) which Tokyo Special Electric Cable Co., Ltd. which is this patent applicant has, for example is used preferably.

  The grinding process is a process in which the end face (2a, 2b) of the metal conductor 2 and the end face (3a, 3b) of the insulating coating 3 are simultaneously ground for one or both ends of the cut metal conductor 2 with the insulating coating. is there. By this processing step, the shape composed of the end faces (2a, 2b) of the metal conductor 2 and the end faces (3a, 3b) of the insulating coating 3 has a hemispherical shape, a conical shape, a conical shape having a hemispherical shape at the tip, Any shape selected from conical shapes having a flat shape is used.

  After this grinding process, a plating process may be provided for plating the end portion after grinding (that is, the end portion where the metal conductor is exposed). By this plating step, a plating layer for reducing contact resistance can be formed at the end.

  Further, after the cutting process, as shown in FIG. 2, there is an insulating film removing step for forming a region where the insulating film 3 is removed by a certain length from the end portion 2a on the tip side of the probe to be measured. You may do it. The end face 3c of the insulating coating 3 on the side from which the insulating coating 3 has been removed is in contact with the guide hole of the guide plate 20 used when measuring the electrical characteristics, and is a stopper that prevents the probe 1 from falling off the guide plate 20 provided in the probe unit 10. Function as. At this time, the insulating film can be removed by irradiating a region to be peeled with a laser beam or using a mechanical peeling means such as a stripper. The removal of the insulating film at this time may be performed before or after the end portion is ground. Further, when the insulating coating is removed after the end portion is ground, the insulating coating may be removed before or after the plating step, but may be performed after the plating step. preferable.

  In the contact probe manufacturing method of the present invention, the example of the manufacturing method shown in FIG. 4 that does not have the above-described insulating film removing step can be applied to the probe shown in FIG. 1, and the probe shown in FIG. The example of the manufacturing method shown in FIG. 5 in which the insulating film removing step is performed only at one end can be applied. In FIG. 5, the one-end film peeling process and the tip part grinding process may be reversed (see Example 2 described later).

  In the present invention, the step of laser-peeling or mechanically peeling the insulating coating at both ends after cutting the long metal conductor with an insulating coating, or the step of spray-coating the insulating coating after masking on the metal conductor of a predetermined length Is an efficient manufacturing method that requires less processing steps and can reduce costs. In addition, when the tip is ground into a shape such as a hemisphere or a cone suitable for a contact probe, an insulating coating of, for example, 0.01 to 0.2 mm can be simultaneously ground and removed from the tip of the metal conductor. Thus, it is possible to reduce or halve the conventional process for removing the insulating film near both ends, and to provide a low-cost contact probe.

(Inspection method of electrical characteristics using probe)
Next, a method for inspecting electrical characteristics using the above-described probe of the present invention will be described. FIG. 6 is a schematic cross-sectional view for explaining a method for inspecting the electrical characteristics of the object to be measured using the probe unit having the contact probe of the present invention. FIG. 7 is a diagram illustrating the probe unit shown in FIG. It is a schematic cross section which shows the example comprised by.

  The probe 1 of the present invention is attached to a probe unit and used for checking the quality of electrical characteristics of a measured object such as a circuit board. As shown in FIGS. 6 and 7, the probe unit 10 includes a plurality of thousands of probes 1, a guide plate 20 that guides the probes 1 to the electrodes 12 of the measured object 11, and the probes 1 of the inspection apparatus. A guide plate 30 for guiding the lead wire 50 is provided. The guide plate 30 on the inspection apparatus side has a guide hole slightly larger than the outer diameter of the probe 1, and the guide hole guides the metal conductor 2 of each probe 1 to the lead wire 50. In the probe unit 10 of the form shown in FIG. 6, the guide plate 20 on the measured object side has a guide hole slightly larger than the diameter of the metal conductor 2, and the guide hole is a metal conductor of each probe 1. 2 is guided to the electrode 21. On the other hand, in the probe unit 10 of the form shown in FIG. 6, the guide plate 20 on the measured object side has a guide hole that is slightly larger than the outer diameter of the probe 1, and the guide hole is one for each probe 1. The metal conductor 2 is guided to the electrode 2.

  The position of the probe unit 10 and the measured object 11 are controlled so that the probe 1 and the electrode 12 correspond to each other when the electrical characteristics of the measured object 11 are inspected. The inspection of the electrical characteristics is performed by moving the probe unit 10 up and down and pressing the tip 2a of the probe 1 against the electrode 12 of the measurement object 11 with a predetermined pressure using the elastic force of the probe 1. At this time, the rear end 2b of the probe 1 comes into contact with the lead wire 50, and an electrical signal from the measured object 11 is sent to the inspection device (not shown) through the lead wire 50. 6 and 7, reference numeral 40 denotes a lead wire holding plate.

  In the contact probe of the present invention, one end portion on the lead wire side shown in FIG. 6 and both end portions shown in FIG. 7 are covered with the insulating coating 3 to the vicinity of the exposed tip of the metal conductor 2. The clearance between the hole and the contact probe is small, the end of the metal conductor 2 can be sufficiently centered, and instability of contact between the metal conductor 2 and the lead wire 50 can be eliminated. Similarly, since the insulating coating 3 is covered up to the vicinity of the tip of the exposed metal conductor 2, when the probe 12 shown in FIG. 7 is used and the electrode 12 of the measured object is formed of a solder bump, Even when the generated solder powder accumulates on the guide plate on the electrode side, there is no problem of shorting adjacent contact probes.

  Hereinafter, the present invention will be described based on examples. Note that the present invention is not limited thereby.

Example 1
As the metal conductor, a long straight beryllium copper wire (outer diameter 0.10 mm) having straightness straightened to 1500 mm with a radius of curvature R in advance was used. In addition, a polyurethane resin-based enamel paint (manufactured by Tohoku Paint Co., Ltd., trade name: TPU5100) was used as the paint for the insulating coating.

  First, the polyurethane-based enamel paint was applied to a wire made of the beryllium copper wire fed from a wire feeder such as a bobbin in a paint tank. After that, the coated paint on the surface of the wire is handled with a felt (paint squeezing tool) just after that to a substantially uniform thickness, and then the wire is introduced into the baking furnace, and the solvent in the paint applied on the wire in the furnace is removed. The process of volatilizing and removing the paint, curing the coating, forming a cured coating layer on the surface of the wire, and drawing it out from the baking furnace, passing the drawn wire again through the paint tank, paint squeezing tool and baking furnace in turn 10 times After repeatedly forming a cured coating layer having an average film thickness of 15 μm on the surface of the wire, it was wound around a winding device such as a take-up bobbin by a pulling device such as a capstan to produce an enameled wire. In this example, the furnace length was 3 m, the furnace temperature was 450 ° C., and the line speed was 100 m / min.

  Next, the long metal conductor on which the insulating coating is formed is cut with a regular cutting machine to cut out a metal conductor with an insulating coating having a length of 25 mm, and both ends of the metal conductor with the insulating coating are beryllium by a grinding apparatus. The copper wire and the insulating coating were simultaneously processed into a hemispherical shape. Grinding was performed by pressing an end face of a metal conductor with an insulating film cut into a fixed length on a rotating disk with emery paper.

  Next, the metal conductor 2 exposed by processing is plated to form two plating layers (total film thickness 2 μm) consisting of a nickel plating layer (film thickness 1.7 μm) and a gold plating layer (film thickness 0.3 μm). Formed. This two-layered plating layer is free of nickel plating solution (trade name; BEL-801, manufactured by Uemura Kogyo Co., Ltd.) after pretreatment such as degreasing and pickling treatment on the end face portion where the metal conductor is exposed. An electrolytic plating treatment was performed, and then an electroless plating treatment was performed with a gold plating solution (trade name; Au-601, manufactured by Meltex Co., Ltd.). Thus, the contact probe manufactured based on the process order of FIG. 4 was obtained.

(Example 2)
As the metal conductor, a long straight beryllium copper wire (outer diameter 0.10 mm) having straightness straightened to 1500 mm with a radius of curvature R in advance was used. In addition, a polyurethane resin-based enamel paint (manufactured by Tohoku Paint Co., Ltd., trade name: TPU5100) was used as the paint for the insulating coating. Next, an enameled wire was produced in the same manner as in Example 1 above.

  Next, the long metal conductor on which the insulating coating is formed is cut with a regular cutting machine to cut out a metal conductor with an insulating coating having a length of 25 mm, and both ends of the metal conductor with the insulating coating are beryllium by a grinding apparatus. The copper wire and the insulating coating were simultaneously processed into a hemispherical shape. Grinding was performed by pressing an end face of a metal conductor with an insulating film cut into a fixed length on a rotating disk with emery paper.

  Next, in order to form the end surface 3c of the insulating coating 3 at a position where it abuts the guide hole of the guide plate 20, a laser beam is irradiated using a laser beam irradiation device (manufactured by Keyence Corporation, model number: ML-9110), and the probe The insulating coating from 2 mm to 2 mm was peeled off. Next, in the same manner as in Example 1, the metal conductor 2 exposed by processing is subjected to a plating treatment to form a two-layer plating comprising a nickel plating layer (film thickness 1.7 μm) and a gold plating layer (film thickness 0.3 μm). A layer (total film thickness 2 μm) was formed. In this way, the contact probe manufactured based on the process order of FIG. 5 (No. 4 and No. 5 were changed) was obtained.

It is a schematic cross section which shows an example of the contact probe of this invention. It is a schematic cross section which shows another example of the contact probe of this invention. It is sectional drawing which shows the example of a characteristic form of the one end part or both ends of the contact probe of this invention. It is a process flow figure showing an example of the manufacturing method of the probe of the present invention. It is a process flow figure showing other examples of the manufacturing method of the probe of the present invention. It is a schematic cross section for demonstrating the method to test | inspect the electrical property of a to-be-measured object using the probe unit provided with the contact probe of this invention. FIG. 7 is a schematic cross-sectional view showing an example in which the probe unit shown in FIG. 6 is configured upside down. It is a schematic cross section which shows an example of the conventional contact probe. It is a schematic cross section for demonstrating the method to test | inspect the electrical property of a to-be-measured object using the probe unit provided with the conventional contact probe.

Explanation of symbols

1 Contact probe 2 Metal conductor 2a, 2b End face (end face)
3 Insulating coating 3a, 3b, 3c End face (end face)
DESCRIPTION OF SYMBOLS 10 Probe unit 11 Measured object 12 Electrode 20 Measured object side guide plate 30 Inspection device side guide plate 40 Lead wire holding plate 50 Lead wire L1-L4 Length of metal conductor

Claims (4)

In the contact probe of the system that has an insulating film on the outer periphery of the pin-shaped metal conductor and obtains a contact pressure against the object to be measured by applying a load to both ends and measuring the electrical characteristics,
One end or both ends of the contact probe are ground at the same time as the processed end surface of the metal conductor exposed at the tip by grinding and the processed end surface of the metal conductor, and the shape along the processed end surface shape of the metal conductor A contact probe comprising: a processed end face of an insulating coating. In the contact probe of the system that has an insulating film on the outer periphery of the pin-shaped metal conductor and obtains a contact pressure against the object to be measured by applying a load to both ends and measuring the electrical characteristics,
The shape of one end portion or both end portions of the contact probe consists of the end face shape of the metal conductor and the end face shape of the insulating coating, and the shape of the one end portion or both end portions is a hemispherical shape, a conical shape, a tip end A contact probe selected from a conical shape having a hemispherical shape and a conical shape having a flat shape at the tip.   The material of the insulating coating is at least one resin selected from polyurethane resin, nylon resin, polyester resin, epoxy resin, polyesterimide resin, polyamide resin, and polyamideimide resin. Contact probe. A method of manufacturing a contact probe that has an insulating coating on the outer periphery of a pin-shaped metal conductor, and obtains a contact pressure against the object to be measured by applying weight to both ends to measure the electrical characteristics. ,
The step of cutting the long metal conductor on which the insulating coating is formed, and the end face of the metal conductor and the end face of the insulating coating are simultaneously ground for one or both ends of the cut metal conductor with the insulating coating. The shape composed of the end face of the metal conductor and the end face of the insulating coating is any one selected from a hemispherical shape, a conical shape, a conical shape having a hemispherical shape at the tip, and a conical shape having a flat shape at the tip. And a step of manufacturing the contact probe.

Images