JPH06213928A - Manufacture of probe head - Google Patents

Abstract

PURPOSE:To provide a method for manufacturing a probe head in which a probe head of a high positional accuracy can be manufactured at a fine pitch by automating the steps of connecting and forming a probe needle on an insulating board. CONSTITUTION:The method for manufacturing a probe head comprises the steps of forming a probe needle of the head by wire bonding, fusion-bonding both ends of the bonded wire 140 in an orientating direction, then arranging the wires 140, and then cutting one sides of the ends to form ends of the needles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a probe head in which probe needles are formed on an insulating substrate.

[0002]

2. Description of the Related Art For example, a probe head used for inspecting the electrical characteristics of a semiconductor element such as an IC wafer is provided with a large number of probe needles in accordance with the number of electrode pads formed on the semiconductor element. Is generally known. Then, for example, tungsten is used for the probe needle. When measuring the electrical characteristics of a semiconductor element using this probe needle, a peeling process of the insulating film by overdrive is performed. In other words, this process is a process performed for the case where the electrode pad of the semiconductor element is formed using a material such as aluminum that easily forms an insulating layer of an oxide film on the surface,
The semiconductor element is further moved toward the probe needle from the position where the electrode pad contacts the probe needle. As a result, when the probe needle slides on the pad surface due to the bending restoring force, the oxide film on the pad surface is peeled off, and the tip of the probe needle can be brought into direct contact with the surface of the aluminum.

In the probe head, a large number of probe needles are manually arranged on a support base.
Further, it is necessary to fix a large number of these probe needles on the supporting base with an adhesive and to electrically connect the ends of the probe needles by manual soldering, which is extremely complicated work.

[0004]

In recent years, as the density of semiconductor elements such as ICs has been rapidly increased in recent years, the array pitch between the electrode pads of the elements has become finer and the number of the electrode pads has significantly increased. It tends to increase. In particular, in the case of liquid crystal displays such as televisions, which have been in high demand in recent years, for example, in the case of 15-inch television displays,
The number of electrode pads may reach up to 4000, and the diameter and arrangement pitch of the probe needles on the probe head side are miniaturized accordingly.

Therefore, there is a limit to the manual operation of arranging, adhering and soldering the probe needles for each of these many points. Moreover, considering that the positional relationship between these probe needles must also be accurately maintained, the work time for manual work increases as the array pitch becomes finer, which may increase the manufacturing cost. Inevitable. Incidentally, when forming the probe needle of the probe head for the above liquid crystal, at least about 100 hours of working time is required.

Therefore, an object of the present invention is to solve the problems in the above-mentioned conventional probe head, and to automate the connection and forming process of the probe needles on the insulating substrate to achieve a fine pitch and a high positional accuracy. An object of the present invention is to provide a method for manufacturing a probe head, which is capable of manufacturing a probe head.

[0007]

To achieve this object, the invention according to claim 1 forms a probe needle on an insulating substrate at a predetermined position on a conductive pattern portion on the insulating substrate. After ultrasonically bonding one end of the wire made of a material having good drawability in the drawing direction, drawing the wire in a predetermined direction and wire-bonding the other end on the conductive substrate, and the wire The method is characterized by including a step of press-fitting into grooves formed in accordance with the arrangement pitch and a step of cutting the other end side of the wire in the extending direction.

According to a second aspect of the invention, in the manufacturing method according to the first aspect, the groove is formed by cutting the base material with a dicing saw.

The invention according to claim 3 is the invention according to claim 1 or 2.
In the manufacturing method described above, the arrangement pitch of the wires press-fitted into the grooves is set to 70 μm to 105 μm when the outer diameter of the wires is 20 μm to 50 μm.

[0010]

In the present invention, when forming the probe needle on the insulating substrate, wire bonding, for example, ultrasonic wave, thermocompression bonding, or wire bonding using both ultrasonic wave and thermocompression bonding is employed.

That is, a material having good plasticity is selected for the wire used for wire bonding, and specifically, gold (Au) having an outer diameter of 20 μm to 50 μm is set.
Copper (Cu) is used. Then, one end in the extending direction of the wire is first bonded to a predetermined position of the conductive pattern portion on the insulating substrate by a wire bonder. After that, the wire is stretched in a predetermined direction, and the other end in the stretching direction is second-bonded to the conductive substrate by a wire bonder. The wire stretched to carry out this second bonding is press-fitted into a groove provided so that the position between the bonded ends is aligned with the array pitch of the probe needles, and the array between the probe needles is arranged. It is fixed while being positioned on the pitch. The arrangement pitch in this case is set in the range of 70 μm to 105 μm when the outer diameter of the probe needle is in the above range. After that, the wire fixed at the position corresponding to the arrangement pitch of the probe needles is cut at the other end side in the extending direction to form the tip portion of the probe needles. Therefore, as in the conventional case, an array for probe needles prepared in advance in large numbers,
It is possible to automate each process by wire bonding which can accurately control the positioning and the welding position without requiring manual work such as adhesive fixing and soldering. Moreover, the work cost can be reduced by shortening the manufacturing time.

Further, in the present invention, the wire used for wire bonding can be directly used as the probe needle.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 shows the appearance of a probe head manufactured by the manufacturing method of the present invention. The probe head 10 has, for example, a liquid crystal display (L) in which the number of electrode pads is considerably larger than that of an IC wafer.
It is intended for a CD and has a take-out substrate 12, a probe needle 14 and a guide portion 16 as main parts.

On the take-out substrate 12, conductive patterns 12A are formed according to the number of electrode pads (not shown) on the liquid crystal side. The conductive pattern 12A has a well-known structure composed of a metal film layer formed on an insulating substrate by a plating process or sputtering. And
In the case of this embodiment, gold (A
u) is used, and when sputtering is used, chrome (Cr) is used.

On the other hand, one end of the probe needle 14 in the extending direction is welded to the conductive pattern of the substrate 12, and the other end is inserted into the groove 16A of the guide portion 16 and protrudes to form the tip of the probe needle. Has been done.

Such a probe head 10 is manufactured by the steps shown in FIG.

First, in manufacturing the probe head 10, as shown in FIG. 2, a take-out substrate 12, a guide portion 16 and a material having a good bonding property, for example, a substrate 18 having a good bonding property plated with gold such as gold are used in the manufacturing apparatus. It is prepared by placing it on the set surface.

The guide portion 16 is made of, for example, an insulating material such as ceramics and has a large number of grooves 16A formed by a dicing saw (circular saw) along the arrangement direction of the probe needles 14. In the case of the present embodiment, the groove 16A is set to have a width and depth, and a forming pitch that allows the wires to be press-fitted according to the outer diameter and the arrangement pitch of the wires for wire bonding, and has a rectangular cross section. Has been done. Further, the substrate 18 having good bonding property is a dummy board which is arranged at a position facing the substrate 12 with the guide member 16 interposed therebetween, and a plating layer made of the same material as a wire for wire bonding described later is formed on the surface thereof. Has been done.

On the other hand, the probe needle 14 is, for example, gold (A
It is formed by wire bonding using an alloy having a good plasticity such as u) or copper (Cu) that has been reduced by hydrogen and subjected to corrosion prevention treatment, or a single material as a wire.
And, in the case of the present embodiment, the wire used for wire bonding (hereinafter, indicated by reference numeral 140 for convenience) is
The outer diameter is set to 25 to 30 μm, and the array pitch is set to 80 to 100 μm with reference to this outer diameter. Regarding the arrangement pitch, for example, in the case of the pattern size of the extraction substrate 12 shown in FIG. 5, the minimum distance of the line pattern extended from the electrode pad is 60 μm, which is extremely narrow. Wire 1
The outer diameter and pitch of 40 are set.

Under such preparation, the probe head 10 is manufactured by the process shown in FIG.

That is, in FIG. 3A, when the tip of the capillary 20 is opposed to the conductive pattern 12A (see FIG. 1) of the take-out substrate 12 placed on the set surface of the manufacturing apparatus, it corresponds to the probe needle 14. Wire 14
0 is rolled out. Then, when the tip of the wire 140 contacts the conductive pattern 12A of the take-out substrate 12, the first bonding is performed. For this first bonding, for example, a method of welding the end portion of the wire to the conductive pattern 12A using ultrasonic waves or thermocompression bonding is adopted.

When the end portion of the wire 140 is welded to the conductive pattern 12A of the take-out substrate 12, the capillary 20 moves in a predetermined direction as shown by the alternate long and short dash line in FIG. The edge is brought into contact with the substrate 18 having good bonding properties. The predetermined direction at this time is
The wire 140 is set to extend along the direction in which the groove 16A is formed. Also, the capillary 2
Since 0 moves in a state of straddling the guide portion 16 so as not to interfere with the guide portion 16, the wire 140 is stretched in an arch shape between one end and the other end in the extending direction, and is placed on the substrate 18 having good bonding properties. The other end in the drawing direction is brought into contact. Then, the other end of the wire 140 in the extending direction is welded by the second bonding, and the bonding in this case uses the above-mentioned method utilizing ultrasonic thermocompression bonding.

In this way, the wires 140, whose ends in the extending direction are welded to the take-out substrate 12 and the substrate 18 having good bonding properties, respectively, are the guide grooves 1 of the guide portion 16.
6A is press-fitted and aligned.

That is, in FIG. 3 (B), the wire 140 stretched in an arch shape is inserted into the groove 16A by sliding the sliding member 22 shown in FIG. 4 on the upper surface of the guide portion 16, for example. Pushed in. Therefore, the wire 14
0 is press-fitted into the groove 16A to be positioned in the arrangement direction and prevented from coming off. It should be noted that the wire 140 is not always stretched in an arch shape, but may be in contact with the upper surface of the guide portion 16. When the wire 140 is pressed into the groove 16A, the lid 16B
As a result, the opening of the groove 16A is closed to prevent the wire 140 from coming off more reliably.

By the way, the wire bonding itself is normally completed by bonding both ends of the wire 140 in the extending direction, but in the present embodiment, the end of the bonded wire is intentionally cut. .

In FIG. 3C, the end portion of the wire 140 located on the side opposite to the take-out substrate 12 side is welded by the second bonding on the substrate 18 having good bonding property, but as shown in FIG. , Is cut while leaving the welded end portion on the substrate 18 having good bonding properties. The end portion on the side protruding from the guide portion 16 by cutting serves as the tip of the probe needle.

This cutting is carried out, for example, by a diamond cutter which is widely used in this kind of field, but it goes without saying that the cutting surface is set to have a shape capable of properly contacting the conductive pad. . For example, there is a ball shape as shown in FIG. 6 (A) or a round shape as shown in FIG. 6 (B) by combining molding processes after cutting. As the molding process in this case, for example, a heating process with a torch or a polishing process with electrolysis is selected. In the case of heat treatment, a ball shape is obtained by the surface tension of the melted tip, and in the case of polishing treatment, a round shape is obtained.

In this embodiment, the above procedure is executed. Therefore, the wire 140 that constitutes the probe needle 14
Is made of gold (Au) or copper (Cu), which has good drawability. The selection of such a material is made based on the goodness of the contact characteristics with the electrode pad, taking into consideration the mechanical characteristics of the probe needle. When gold (Au) is selected as the material of the wire, for example, when measuring the electrical characteristics of the liquid crystal, there are the following advantages.

That is, there is a transparent electrode formed on the liquid crystal side, which is made of ITO having a relatively high surface resistance value. With respect to such an electrode, it is said that there is no hindrance to the measurement of electrical characteristics if the contact of the probe needle is accurately guaranteed even if there is contact resistance. Therefore, when the probe needle is made of gold (Au), the operation of simply bringing the probe needle into contact with each other does not require a treatment such as peeling off the insulating layer formed on the surface, as in the case of an aluminum electrode pad. OK.

The present invention is not limited to the above embodiment, but various modifications can be made within the scope of the invention.

For example, gold (Au), which is one of the materials of the wire used for wire bonding, has lower bending rigidity and hardness than tungsten or the like. Therefore, when rigidity or hardness is required, the surface of the wire may be metal-plated by an electric field or the like so as to have necessary mechanical characteristics. Also, in order to have mechanical properties,
As the material composition of the wire that constitutes the probe needle, gold (A
u) and copper (Cu) in the atomic ratio, Au: Cu =
An alloy containing 1: 1 may be used. By changing such mechanical properties, for example, not only the liquid crystal targeted in the above-mentioned examples, but also the element having a composition that can be measured under the condition of contact even if surface resistance is present It is also possible to expand the applicable range.

Further, in the above-mentioned embodiment, the case where the probe needle is stretched is linear, but in the drawing,
For example, the end side corresponding to the tip of the probe needle can be bent. Therefore, in this case, the probe needle can be properly positioned according to the relationship between the installation position of the probe head and the position of the semiconductor element.

Further, in the above-mentioned embodiment, a single probe head has been described, but, for example, as shown in FIG. 7, the probe heads are arranged in a plurality of rows by joining the single probe heads. It is also possible to do so. In this case, the arrangement direction of the probe needles is set in a direction perpendicular to the arrangement direction of the probe needles with a single probe head, so that the so-called matrix-shaped electrode pads are arranged. Can also be measured. Note that FIG. 7 shows a state in which the direction of the probe head 10 when actually used for the electrode pad is reversed.

The guide portion having the groove into which the wire is press-fitted is not limited to the groove formed by the dicing saw, but may be formed in a shape including the groove, for example, by molding using resin. is there. Further, the step of press-fitting the wire into the groove may be performed after cutting.

The wire used for wire bonding can be directly formed as a probe needle. Therefore, depending on the selection of the material of the wire, the over-driving, which has been conventionally required at the time of measuring the semiconductor element, that is, the pre-preparation step for the measurement step can be eliminated, and the measurement time can be shortened. For this reason, it is possible to shorten the time when a large number of semiconductor devices are measured and improve the mass production efficiency of the semiconductor devices including the time required for the characteristic inspection process.

[0037]

As described above, according to the present invention, the probe needle of the probe head is formed by wire bonding. Then, after both ends in the extending direction are welded by wire bonding, one end of the ends is cut to form the tip of the probe needle. Therefore, it is possible to eliminate the need for specially preparing the probe needles, and to eliminate the need for manual alignment, adhesive fixing, and soldering. Moreover, even when the array pitch and the outer diameter of the probe needle are made fine, automation can be performed by wire bonding, so that the work time can be shortened and the cost required for the work can be reduced.

[Brief description of drawings]

FIG. 1 is an external view of a probe head obtained by a manufacturing method according to the present invention.

FIG. 2 is a perspective view schematically showing a configuration for carrying out the manufacturing method according to the present invention.

3A and 3B are schematic diagrams for explaining each step of the manufacturing method according to the present invention, in which FIG. 3A is a first bonding step and a second bonding step, FIG. 3B is a press-fitting step into a groove, and FIG. Each of the cutting steps is shown.

FIG. 4 is a schematic diagram for explaining means used in the press-fitting step shown in FIG. 3 (B).

FIG. 5 is a schematic plan view showing a state of the cutting step shown in FIG. 3 (C).

FIG. 6 is a schematic view showing a tip shape of a probe needle,
(A) shows a case of a ball shape, and (B) shows a case of a round shape.

FIG. 7 is a schematic perspective view showing one application example of a probe head obtained by the manufacturing method according to the present invention.

[Explanation of symbols]

 10 probe head 12 take-out substrate 14 probe needle 16 guide portion 16A groove 18 conductive substrate 22 sliding member

Claims (3)

[Claims] 1. When forming a probe needle on an insulating substrate, after wire-bonding one end of a wire made of a material having good stretchability in a drawing direction at a predetermined position on a conductive pattern portion on the insulating substrate. A step of stretching the wire in a predetermined direction and ultrasonically bonding the other end of the wire on a conductive substrate; a step of press-fitting the wire into a groove formed according to the arrangement pitch thereof; And a step of cutting the other end side in the drawing direction. 2. The manufacturing method according to claim 1, wherein the groove is formed by cutting a base material with a dicing saw. 3. The manufacturing method according to claim 1, wherein the arrangement pitch of the wires press-fitted into the grooves is 50 μm to 120 μm when the outer diameter of the wires is 20 μm to 50 μm.
A method for manufacturing a probe head, characterized in that