JPH06347481A - Probe structure - Google Patents

Abstract

PURPOSE:To secure the contact of a bump and an electrode by putting in the bump together with an insulating base material in an through hole, giving a cushion effect in a continuety test, and correcting the unevenness of the distance between the bump and the electrode of a semiconductor, when a pressure head is lowered, and the bump and the electrode of a semiconductor are made to abut against each other. CONSTITUTION:A lead 2 is placed between an insulating base material 1 and a dielectric layer 5, and a bump 3 is formed on the other side surface of the insulating base material 1. A conductive passage 4 to connect the lead 2 and the bump 3 is formed in the thickness direction of the insulating base material 1. A through hole 6 penetrating in the thickness direction is formed in the dielectric layer 5. The diameter of the through hole 6 is larger than the diameter of the conductive passage 4, and the area N of the through hole 6 includes the area n where the conductive passage 4 is formed. And the center point of the through hole 6 is coincident to the center point of the conductive passage 4, or almost coincident with it.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a probe structure,
Especially used for semiconductor device assembly, semiconductor device assembly such as wafer on which semiconductor device before dicing is formed, TAB, continuity inspection of semiconductor device, semiconductor device mounting circuit board, wiring circuit continuity inspection of LCD circuit substrate, etc. The present invention relates to a probe structure provided at the tip of a test device such as a tester.

[0002]

2. Description of the Related Art In recent years, high-density mounting technology has advanced mainly in semiconductor technology, the number of electrodes in a related device group has increased, and the formation of electrodes has become finer. Moreover, as the number of expensive parts increases, the demand for inspection equipment is becoming more and more severe. Conventionally, needle type probes have been used for semiconductor chips, TAB
In a packaged semiconductor device, a spring-type pin probe has been used in a dedicated socket, and an FPC terminal probe has been used in the panel inspection of an LCD, which is a typical display device.

However, such a method cannot follow the inspection of high-density electrodes, or cannot cope with the electrode arrangement changing from the array type to the area type. In order to meet the demands of such an inspection apparatus, a probe structure with bump-shaped metal protrusions (hereinafter referred to as "bumps") has been proposed (for example, Japanese Patent Laid-Open No. 2323736).
No. 9, JP-A-3-293566, etc.).

FIG. 9 is a sectional view showing a conventional probe structure with bumps. According to the probe structure P4, the problems of the electrode density and the electrode arrangement described above can be solved, but since the bumps 90 serving as contacts have no cushioning property, the bumps 90 are mounted on the electrodes 92 of the semiconductor element 91 as the inspection object. In order to prevent the electrode 92 from being damaged during the contact, the pressure head 93
The cushion member 94 must be interposed between the probe structure P4 and the probe structure P4, and there is a problem of contamination from the cushion member and dimensional change due to expansion and contraction of the cushion member.

Further, in order to ensure electrical continuity with the electrodes 92 during the continuity inspection, it is necessary to form the bumps 90 to have a uniform height, but if the number of the electrodes 92 increases, it is difficult to control them. Alternatively, if the electrode 92 does not have flatness, the contact with the bump 90 may be incomplete, which may cause a problem in the result of the continuity test.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a cushioning effect on an object to be inspected at the time of a continuity inspection, and a contact portion and a terminal of the object to be inspected. It is an object of the present invention to provide a probe structure that can reliably conduct electricity to a terminal of a device under test by eliminating a connection failure due to a variation in the distance between them.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to achieve the above object, and as a result, by providing the following probe structure, a cushioning effect can be obtained during a continuity test. The inventors have found that a poor connection due to variations in height with the terminals of the device under test is eliminated, and have completed the present invention.

That is, in the probe structure of the present invention, the circuit wiring connected to the test equipment for conducting the continuity inspection of the object to be inspected is laminated between the insulating base material and the dielectric layer, On the surface of the base material opposite to the surface on which the circuit wiring is formed,
A contact portion that contacts the terminal of the device under test is formed, and a conduction path that connects the circuit wiring and the contact portion is formed in the thickness direction of the insulating base material, and in the plane direction of the dielectric layer. A recess is formed on the surface of the dielectric layer, the recess being larger than the width of the conductive path and including the region of the conductive path.

Further, the center point of the recess is deviated from the center point of the conducting path.

Further, a coating layer for coating the recess is laminated on the dielectric layer.

In the present invention, "inspection object" means a semiconductor element, a semiconductor element assembly (a silicon wafer before dicing, a silicon chip after dicing, etc.), a semiconductor device, a semiconductor device mounting circuit board, an LCD circuit board. The term “terminal” includes the concepts of electrodes, pads, and lands. “Circuit wiring” is a broad concept including not only a wiring pattern but also electrodes, leads and the like. "Test equipment" means not only testers but also, for example,
It also includes a device used for impedance matching between the device under test and the circuit wiring.

The term "contact part" means a conductor which is brought into conduction when it comes into contact with a terminal of a device under test. The shape of the “contact point” is not particularly limited, and includes flat surfaces such as triangles, squares, rectangles, trapezoids, parallelograms, other polygons and circles, or prisms, cylinders, spheres, cones (cones, pyramids), etc. It may be three-dimensional. The insulating base material does not necessarily have to be formed so as to project outward from the surface of the insulating base material, and can be arbitrarily set depending on the layout of the device under test, the shape of the circuit, and the like. Similarly, the shape of the “conduction path” is not limited.

Similarly to the contact portion, the shape of the "recess" is not limited, and the recess is formed on the surface of the dielectric layer opposite to the circuit wiring side (either one surface or both surfaces of the dielectric layer). It may be formed so as to penetrate the dielectric layer so that the circuit wiring and the dielectric layer are exposed.

[0014]

According to the probe structure of the present invention, since the recess which is larger than the width of the conductive path in the surface direction of the dielectric layer and includes the area of the conductive path is formed on the surface of the dielectric layer, it is possible to form the contact portion. When the terminals of the device under test come into contact with each other, the stress causes the insulating base material in the region where the recess is formed to enter the recess. Therefore, the circuit wiring, the conductive path, and the contact portion in the region enter the recess together with the insulating base material, so that the cushion effect of the contact portion can be obtained and the terminal of the device under test can be prevented from being damaged. Furthermore, since the variation in the distance between the contact portion and the terminal of the device under test is corrected, the compliance is further improved, and the electrical connection becomes more reliable.

Further, when the center point of the concave portion is deviated from the center point of the conducting path, the distance from the central point of the conducting path to the peripheral edge of the concave portion varies. The contact part tilts along with the passage, and the contact part slides in contact with the surface of the terminal of the DUT, and the frictional force rubs the oxide formed on the surface of the terminal and the insulating layer due to adhesion, transfer, etc. The connection between the terminal and the contact portion is ensured.

Further, when the coating layer for coating the recess is laminated on the dielectric layer, the coating layer seals the gas or liquid in the recess and resists the stress caused by the contact between the contact portion and the terminal. When the internal pressure in the recess increases and the contact part and the terminal are separated from each other, the insulating base material is pushed outward, and the contact part is restored to the original state. Therefore, the cushioning property of the contact part is improved, the contact part is restored more reliably, and the continuity with the terminal is assured in the continuity test thereafter.

[0017]

EXAMPLES Examples will be given below to explain the present invention in detail, but the present invention is not limited to these examples.

FIG. 1 is a sectional view showing an example of the probe structure of the present invention, and FIG. 2 is a plan view of the probe structure P1 shown in FIG. Probe structure P shown in FIG.
1, a lead 2 which is a circuit wiring is formed on one surface 1a of the insulating base material 1, and the lead 2 is connected to a test device (tester) not shown. The leads 2 are electrically connected to the circuit pattern of the device under test and the electrode terminals on the semiconductor element by the bumps 3 and the conduction paths 4 which will be described later, so that the continuity test can be performed to determine whether or not the leads 2 have a predetermined function. Wired in the linear pattern.

On the other surface 1b of the insulating base material 1,
Bumps 3 which are contact portions formed so as to project outward from the surface 1b of the insulating base material 1 are formed, and the bumps 3 come into contact with the electrodes 11 on the semiconductor element 10 which is the device under test. Is formed in position.

A conductive path 4 penetrating the insulating base material 1 in the thickness direction is formed in the area in which the lead 2 contacts the insulating base material 1 or in the vicinity of the area including the area. The passage 4 is connected to the lead 2 and the bump 3. The shape of the bumps 3 is not particularly limited, but it is preferable that the bumps 3 have a mushroom shape as shown in the figure in order to surely make contact with a device under test such as a semiconductor element, an electric circuit, or an electric circuit component.

In the present invention, as shown in FIG. 1, the contact portion does not rise in a bump shape, and the surface 1 of the insulating substrate 1
It goes without saying that a mode in which the conduction path 4 is formed on the same plane as b and the end portion of the conduction path 4 serves as a contact portion is also included.

A dielectric layer 5 is laminated on one surface 1a of the insulating base material 1 to cover a part of the lead 2. The dielectric layer 5 is provided with a through hole 6 penetrating in the thickness direction, and the lead 2 and a part of the insulating base material 1 are covered with the through hole 6.
Exposed through. The diameter of this through hole 6 is equal to
Region N of the through hole 6 includes a region n in which the conduction path 4 is formed. Further, the center point of the through hole 6 coincides with or substantially coincides with the center point of the conduction path 4, and the distance from the center point of the conduction path 4 to the peripheral portion of the through hole 6 is It is almost equal to the radius and uniform.

In this embodiment, the through hole 6 is a circular hole, but the through hole 6 is not particularly limited to a circular hole, and the shape of the conducting path 4 is not particularly limited to a cylindrical shape. Furthermore, the recess formed in the dielectric layer 5 may not be penetrated, and for example, the recess may be formed to the extent that the lead 2 and the insulating base material 1 are not exposed. That is, the thickness of the dielectric layer 5 in the region where the recess is formed is smaller than the thickness of the dielectric layer 5 in the region other than the recess, and a gap is formed to allow a part of the insulating base material 1 to enter. If you have.

FIG. 3 is a cross-sectional view showing a continuity test using the probe structure P1. At the time of the continuity test, the probe structure P1 is interposed between the semiconductor element 10 which is the object to be inspected and the pressure head 20, the probe structure P1 and the semiconductor element 10 are aligned, and then the pressure head 20 is moved. The bump 3 is moved in the direction close to the semiconductor element 10 (downward in FIG. 1) to bring the bump 3 into contact with the electrode 11 of the semiconductor element 10. Further, by lowering the pressure head 20, the insulating base material 1 comes close to the semiconductor element 10, and the bump 3
Together with the insulating base material 1 in the region N of the through hole 6 penetrates directly into the through hole 6 and has a cushioning effect at the time of the continuity test. By the bumps 3 entering the through holes 6,
The height variation of the bump 3 and the electrode 11 of the semiconductor element 10 is corrected, and the contact between the bump 3 and the electrode 11 is ensured.

After that, a signal of a specific frequency for inspecting the circuit of the semiconductor element 10 is input from the tester (not shown) to the electrode 11 of the semiconductor element 10 via the bump 3, and the continuity inspection of the semiconductor element 10 is performed. Be seen. After the continuity test is completed, when the pressure head 20 is displaced in the direction away from the semiconductor element 10 (upward in FIG. 3),
The stress applied to the bumps 3 is relaxed, the expansion of the insulating base material 1 is restored, and the state shown in FIG. 1 is restored.

The material for forming the insulating base material 1 and the dielectric layer 5 is not particularly limited as long as it has electric insulation properties and has appropriate flexibility. Specifically, polyester resin, epoxy resin, urethane resin, polystyrene resin, polyethylene resin, polyamide resin, polyimide resin, acrylonitrile-
A thermosetting resin or a thermoplastic resin such as a butadiene-styrene (ABS) copolymer resin, a polycarbonate-based resin, a silicone-based resin, or a fluorine-based resin can be used. Among these resins, those having a light-transmitting property are preferable from the viewpoint of easiness of alignment at the time of continuity inspection, and further, polyimide resin is particularly preferably used from the viewpoint of heat resistance and mechanical strength. .

The thickness of the insulating substrate 1 and the dielectric layer 5 is
Although not particularly limited, in order to have sufficient mechanical strength and flexibility, it is 5 to 500 μm, preferably 5 to 1
Set to 50 μm. The forming materials of the insulating base material 1 and the dielectric layer 5 may be different from each other, but it is preferable to use the same forming material from the viewpoint of warpage of the probe structure itself.

The material for forming the leads 2, the bumps 3, and the conductive paths 4 is not particularly limited as long as it has conductivity, and known metal materials can be used. For example, gold, silver, copper, platinum. , Single metals such as lead, tin, nickel, cobalt, indium, rhodium, chromium, tungsten, and ruthenium, or various alloys containing these,
For example, solder, nickel-tin, gold-cobalt, etc. may be mentioned. Usually, a metal that is hard and resistant to oxidation and has a low electric resistance, such as rhodium, so that the oxide layer on the electrode 11 which is the terminal of the device under test or the insulating layer on the wiring pattern can be destroyed. Noble metals such as aluminum, ruthenium and platinum are preferably used.

The thickness of the lead 2 is not particularly limited,
It is set to 1 to 200 μm, preferably 5 to 80 μm.
The height of the bump 3 from the surface 1b of the insulative base material 1 is not particularly limited and can be arbitrarily set according to the size of the terminal of the DUT to be contacted, and is usually 0.1 μm.
The thickness is preferably m to several hundreds of μm. The bump 3 is shown in FIG.
In addition to mushroom-shaped (umbrella-shaped) as shown in, hemispherical,
It is formed into a spherical shape.

The material forming the conductive path 4 is the bump 3
It may be either the same substance as the forming material constituting the above or a different substance, but usually the same substance is used, and in this case, the bump 3 and the conductive path 4 may be integrally formed. It is preferable in manufacturing.

The bump 3 is not limited to a single metal layer, but may have a multi-layer structure using a plurality of kinds of metals in order to control physical properties suitable for the terminals of the device under test. For example, when the bump 3 is used for a contact to which stress is repeatedly applied or when it is necessary to bite into the terminal of the DUT, a relatively hard metal such as nickel is used for the core metal of the bump 3. It is preferable to form a multi-layered structure using a joining metal such as gold or solder as the surface metal.

FIG. 4 is a sectional view showing another embodiment of the probe structure of the present invention, and FIG. 5 is a plan view of the probe structure P2 shown in FIG. In the following embodiments, the same reference numerals as those in FIGS. 1 to 3 denote the same or corresponding parts. It should be noted in the probe structure P2 shown in FIGS. 4 and 5 that the center point of the through hole 6 is deviated from the center point of the conduction path 4 and the distance from the center point of the conduction path 4 to the peripheral portion of the through hole 6 is increased. The point is that the distance is different. According to the present embodiment, as shown in FIG. 4, the insulating base material 1 enters the through holes 6 as stress is applied to the bumps 3 during the continuity test. At this time, since the conductive path 4 is formed to be displaced from the recessed bottom portion 1c of the insulating base material 1, the bump 3 is inclined together with the conductive path 4, and the bump 3 comes into contact with the surface of the electrode 11 of the semiconductor element 10. It slides in the state, and the frictional force scrapes off the oxide film, contaminants, etc. formed on the surface of the electrode, and ensures the electrical continuity between the bump and the electrode 11.

FIG. 6 is a sectional view showing still another embodiment of the probe structure of the present invention, and FIG. 7 is a sectional view showing a continuity test using the probe structure P3 of FIG. What should be noted in the probe structure P3 shown in FIGS. 6 and 7 is that the coating layer 7 that covers the through holes 6 is laminated on the dielectric layer 5. By forming the coating layer 7, the through hole 6 is closed and the buffer layer 8 is formed. Gas or liquid is hermetically sealed in the buffer layer 8. When the pressure head 20 is lowered, the internal pressure in the buffer layer 8 rises against the stress due to the contact between the bump 3 and the electrode 11. . When the pressure head 20 is raised after the continuity inspection is completed, the stress applied to the bumps 3 is reduced, and the insulating base material 1 is pushed outward due to the difference between the internal pressure and the stress in the buffer layer 8. , The bump 3 is restored to the state shown in FIG. in this way,
Since the bump 3 is restored by utilizing the change in the internal pressure of the buffer layer 8 sealed by the coating layer 7, the cushioning property of the bump 3 is improved, and the restoration of the bump 3 becomes more reliable.

The material for forming the coating layer 7 is the same as the material for forming the insulating base material 1 and the dielectric layer 5, and the thickness of the coating layer 7 is not particularly limited, but a sufficient mechanical strength is used. 5 to 50 in order to have dynamic strength and flexibility
The thickness is set to 0 μm, preferably 5 to 150 μm.

FIG. 8 is a sectional view showing a manufacturing process of the probe structure of the present invention, which can be manufactured, for example, as follows.

First, as shown in FIG. 8 (a), a laminated base material formed by laminating a conductive material layer 9 on one surface 1a of the insulating base material 1 by a known method is prepared. To do. Examples of the method for forming the conductive material layer 9 on the one surface 1a of the insulating base material 1 include methods such as sputtering, various vapor depositions, and various platings. In addition, a conductive foil is used as the conductive material layer 9, and the insulating base material 1 is laminated on the conductive foil, or an insulator is applied on the conductive foil and solidified to form the conductive material layer 9 The method of forming the insulating base material 1 on the surface is mentioned.

Next, as shown in FIG. 8B, a resist layer is formed on the surface 9a of the conductive material layer 9 to insulate it, and then the leads 2 are formed by a chemical etching process using a photo process. The resist in the area other than the area to be formed is removed. Then, the conductive material layer 9 is etched,
The leads 2 are formed by forming a desired linear pattern.

Next, as shown in FIG. 8C, a dielectric layer 5 covering the leads 2 is formed on the one surface 1a of the insulating base material 1 by a method such as casting or pressure bonding.

Next, as shown in FIG. 8D, fine through holes 9 are formed by punching only the positions on the other surface 1b of the insulating base material 1 where the bumps 3 are to be formed. The fine through holes 9 are formed by penetrating only the insulating base material 1, and the leads 2
Are partially exposed through the fine through holes 9.

The fine through holes 9 are formed by mechanical punching such as punching, plasma processing, laser processing, photolithography processing, or chemical etching using a resist having different chemical resistance from the insulating base material 1, In order to correspond to the fine pitch, it is possible to provide the holes at an arbitrary hole diameter or hole pitch by a method such as laser processing which enables fine processing. Among them, the laser processing method of irradiating an ultraviolet laser such as an excimer laser whose pulse number or energy amount is controlled is particularly preferable from the viewpoints of fine processability and degree of freedom of processed shape. The diameter of the fine through holes 9 is 5 to 1000 μm, preferably about 5 to 500 μm. The diameter of the fine through holes 9 is increased to such an extent that adjacent fine through holes are not connected to each other and the pitch between the fine holes is made as small as possible to increase the number of the fine through holes 9 in contact with the leads 2. This is preferable in reducing the electric resistance of the conductive path 4 formed in the hole 9.

Next, as shown in FIG. 8E, the fine through holes 9 are filled with a conductive material to form the conductive paths 4 and the bumps 3.

The conductive paths 4 and the bumps 3 are formed by physically embedding a conductive material in the fine through holes 9, or by CVD.
Method, plating method such as electrolytic plating or electroless plating, wire bonding method, cream solder potting method, chemical to deposit the conductive material by immersing and pulling up the structure obtained in the above step in a molten bath of conductive material Although it can be performed by a method or the like, an electrolytic plating method using the lead 2 as an electrode is preferable from the viewpoints of easy formation of fine protruding electrodes and workability. In the present invention, the term “filling with a conductive substance” includes not only physical filling of a conductive substance but also the above-mentioned chemical deposition and the like. It is a broad concept that also includes hole plating.

Finally, as shown in FIG. 8F, on the surface of the dielectric layer 5 opposite to the surface on which the insulating base material 1 is formed,
A through hole 6 is formed. The diameter of the through hole 6 is set to be larger than that of the fine through hole 9 described above, and is usually 2 to 100 times the diameter of the fine through hole 9, preferably about 2 to 10. Further, in the case of the probe structure P1 shown in FIGS. 1 to 3, the center point of the through hole 6 is set so as to coincide with or substantially coincide with the center point of the fine through hole 9. In the case of the probe structure P2 shown in FIG. 5, the through hole 6
The center point of is set so as to deviate from the center point of the fine through hole 9. The deviation between the center point of the through hole 6 and the center point of the fine through hole 9 is 1/100 to 10 times the hole diameter of the fine through hole 9,
It is preferably about 1/10 to 1 times.

Although the through holes 6 may be formed in the same manner as the above-described fine through holes 9, one of the insulating base materials 1 is formed after the step of FIG. The surface 1a may be formed by pressure-bonding a dielectric layer in which the through holes 6 are previously formed.

Through the above steps, FIGS.
The probe structure P1 shown in FIG. 6 is manufactured. To manufacture the probe structure P3 shown in FIGS. 6 and 7, the coating layer 7 is further laminated on the dielectric layer 5 by pressure bonding or the like.

[0046]

As described above, the probe structure of the present invention is
The probe structure itself has a cushioning property, and does not require any other material for giving a cushioning effect when conducting a continuity test, and is suitable for semiconductors, high-density electrical components, electrical circuits, and other devices under test. The conduction test can be performed accurately and easily. Even if the DUT lacks flatness, the variation in the distance between the contact point and the terminal of the DUT is corrected, which further improves compliance and improves electrical connection. It will be more certain.

When the center point of the concave portion is deviated from the center point of the conduction path, the contact portion slides in contact with the surface of the terminal of the object to be inspected during the conduction inspection, and the frictional force causes the contact point portion to slide. The oxide formed on the surface of the terminal and the insulating layer formed by adhesion, transfer, or the like are scraped off, so that electrical continuity between the terminal and the contact portion is ensured.

Further, when the coating layer for covering the concave portion is laminated on the dielectric layer, the cushioning property of the contact portion is improved and the contact portion is restored more reliably, and the terminal is checked in the continuity test thereafter. Conduction with is reliable.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a probe structure of the present invention.

2 is a plan view of the probe structure P1 shown in FIG. 1. FIG.

3 is a cross-sectional view showing a continuity test using the probe structure P1 shown in FIG.

FIG. 4 is a cross-sectional view showing another embodiment of the probe structure of the present invention.

5 is a plan view of the probe structure P2 shown in FIG. 4. FIG.

FIG. 6 is a sectional view showing still another embodiment of the probe structure of the present invention.

7 is a sectional view showing a continuity test using the probe structure P3 shown in FIG.

FIG. 8 is a cross-sectional view showing the manufacturing process of the probe structure of the present invention.

FIG. 9 is a cross-sectional view showing a conventional probe structure with bumps.

[Explanation of symbols]

 1 Insulating Substrate 1a One Surface 1b Other Surface 2 Lead (Circuit Wiring) 3 Bump (Contact Point) 4 Conducting Path 5 Dielectric Layer 6 Through Hole (Concave) 7 Cover Layer 10 Semiconductor Element (Inspection Object) 11 Aluminum Electrode (Terminal) P1, P2, P3 probe structure

Claims (3)

[Claims] 1. A circuit wiring connected to a test device for conducting a continuity test of an object to be inspected is layered between an insulating base material and a dielectric layer, and the circuit wiring of the insulating base material is On the surface opposite to the formed surface, a contact portion that contacts the terminal of the DUT is formed, and a conduction path that connects the circuit wiring and the contact portion is formed in the thickness direction of the insulating base material. A probe structure characterized in that a concave portion is formed on the surface of the dielectric layer, the recess having a width larger than the width of the conductive path in the surface direction of the dielectric layer and including a region of the conductive path. 2. The probe structure according to claim 1, wherein a center point of the recess is displaced from a center point of the conduction path. 3. The probe structure according to claim 1, wherein a coating layer that covers the recess is laminated on the dielectric layer.