JPH06347480A - Probe structure - Google Patents

Abstract

PURPOSE:To prevent the damage of a bump and an electrode by disintgrating the pressure loaded on the electrode so as to reduce the force loaded in the vertical direction (the thickness direction) of the electrode, when the bump and the electrode are made to abut against each other. CONSTITUTION:A bump 3 is formed on the rear side 1b of an insulating layer 1, and a lead 2 is formed on the front side 1a of the insulating layer 1. A conductive passage 4 to connect the lead 2 and the bump 3 is formed by penetrating in a oblique direction of the insulating layer 1. In the continuety testing, a holder 6 is fixed to the front side 1a of the insulating layer 1 where the lead 2 is formed, through an adhesive layer 5. A probe structure P1 and a semiconductor element 10 are positioned, and the bump 3 and an aluminum electrode 11 are made to abut against each other. A signal of a specific frequency to detect the continuety of the circuit of the semiconductor element 10 is input to the electrode of the semiconductor element 10 from a tester through the bump 3, so as to carry out the continuety test of the semiconductor element 10.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a probe structure,
Particularly, it is used for a semiconductor element assembly, a semiconductor element assembly such as a wafer on which semiconductor elements before dicing are formed, a continuity inspection of a semiconductor device, and a continuity inspection of a wiring circuit such as a semiconductor device mounting circuit board and an LCD circuit board. The present invention relates to a probe structure provided at the tip of test equipment such as a tester.

[0002]

2. Description of the Related Art In recent years, the semiconductor wafer manufacturing technology has been remarkably developed, and along with this, finer patterns of IC wiring have been developed, and the number of substrates on which ICs with such fine patterns are mounted are increasing year by year. Usually, such a substrate is made of a copper clad laminate, a glass substrate, a ceramic substrate, etc. For the continuity inspection of a substrate having a fine pattern, conventionally, a mechanical probe such as a needle probe is used to inspect one by one. Was going on.

On the other hand, with the miniaturization of patterns, card-type probes have been developed because the mechanical probe described above has difficulty in alignment during inspection and may damage the pattern during alignment. Therefore, the continuity check can be performed collectively. Also,
A probe in which a plurality of bump-shaped metal protrusions are formed has been proposed for the purpose of relaxing the pressure when the electrode pad of a semiconductor element is pressed (see Japanese Patent Application No. 4-179683).

[0004]

However, in such a card-type probe, a plurality of hemispherical (dome-shaped) metal protrusions are formed in a portion which contacts the pattern of the circuit to be inspected, that is, a head portion. In this case, a step of forming a metal protrusion as a core and then masking with a resin or the like is indispensable, and a lot of time and cost are required for manufacturing the probe. Further, even if a metal protrusion that abuts on the electrode pad is formed around the head portion, it is loaded when the core metal protrusion is pressed through the conduction path formed in the thickness direction of the insulator layer. Since the pressure applied to the electrode pad is applied vertically to the electrode pad, damage to the electrode pad cannot be prevented.

Therefore, the inventors of the present invention have solved the problems of the conventional card type probe described above, prevent damage to the electrode pads of the object to be inspected during the continuity inspection of the object to be inspected, and, at the same time, protrude the metal of the probe. The present invention has been completed through intensive improvements in order to provide a probe structure capable of preventing damage to the object itself.

[0006]

That is, in the probe structure of the present invention, a contact portion that abuts a terminal of a device under test is formed on one surface of an insulating layer, and the other surface of the insulating layer is formed on the other surface.
Circuit wiring connected to a test device for conducting a continuity test of the device under test is formed, and the contact portion and the circuit wiring are connected by a conductive path formed in an oblique direction of the insulator layer. It is characterized by being

In the present invention, the "inspection object" means a semiconductor element, a semiconductor element assembly (such as a silicon wafer before dicing and a silicon chip after dicing), a semiconductor device, a semiconductor device mounting circuit board, an LCD circuit board. Etc. The "contact part" means a terminal (pad, pad,
A conductor that conducts electricity when connected to a land, etc., and its shape is not particularly limited, and may be a triangle, a square, a rectangle, a trapezoid, a parallelogram, another polygon, a plane such as a circle, or a prism, a cylinder, It may be a three-dimensional body such as a sphere or a cone (cone or pyramid), and does not necessarily have to be formed so as to project outward from the surface of the insulator layer. It can be designed arbitrarily according to the shape and the like.

Further, the "test equipment" includes not only a tester but also a device used for impedance matching between a device under test and circuit wiring, for example. “Circuit wiring” is a broad concept including not only a wiring pattern but also electrodes, leads and the like. "Connecting" means
It means to be electrically connected by physical connection.

[0009]

In the probe structure of the present invention, since the contact portion and the circuit wiring are connected by the conductive path formed in the insulator layer in the oblique direction, the contact portion and the terminal of the device under test are brought into contact with each other. At this time, the pressure applied to the terminal of the inspection object is decomposed, and the force applied in the vertical direction (thickness direction) of the terminal is reduced. Therefore, damage to the contact portion and the terminal can be prevented.

[0010]

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 embodiment of the probe structure of the present invention. Probe structure P1 shown in FIG.
In the above, a lead 2 which is a circuit wiring is formed on the surface 1a of the insulator layer 1, and the lead 2 is connected to a test device (tester) not shown. Lead 2
A desired linear pattern is electrically connected to a circuit pattern of an object to be inspected or an electrode terminal on a semiconductor element by a bump 3 and a conduction path 4 which will be described later, so that a continuity inspection can be performed to determine whether or not it has a predetermined function. Wired at.

In addition, bump-shaped metal protrusions (hereinafter simply referred to as "bumps") which are contact portions formed on the surface 1b of the insulating layer 1 so as to project outward from the surface 1b of the insulating layer 1. ) 3 is formed, and the bump 3 is formed at a position where it abuts the aluminum electrode 11 on the semiconductor element 10 which is the object to be inspected.

In the area where the lead 2 contacts the insulator layer 1,
Alternatively, a conduction path 4 penetrating the insulator layer 1 in an oblique direction is formed in the area including the area, and the conduction path 4 is connected to the lead 2 and the bump 3.

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

In the inspection, for example, the support 6 is fixed to the surface 1a of the insulator layer 1 on which the leads 2 are formed, with the adhesive layer 5 interposed therebetween, and the probe structure P1 and the semiconductor element 10 are aligned with each other. To do. The probe structure P1 and / or the semiconductor element 10 is displaced in a direction in which they are close to each other, and the bump 3 and the aluminum electrode 11 are brought into contact with each other. A signal of a specific frequency for inspecting the circuit of the semiconductor element 10 is input from the tester to the electrode terminal 11 of the semiconductor element 10 via the bump 3 to inspect the semiconductor element 10 for continuity. After the continuity test is completed, the probe structure P1 and / or the semiconductor element 30 are moved in directions away from each other, and the above operation is repeated in order to conduct a new semiconductor element continuity test.

Since the lead 2 and the bump 3 are connected by the conductive path 4 formed in the insulator layer 1 in the oblique direction, when the bump 3 and the aluminum electrode 11 are brought into contact with each other, the semiconductor element 10 is connected. The pressure applied to the aluminum electrode 11 is decomposed, and the force applied in the vertical direction (thickness direction) of the aluminum electrode 11 is reduced. Therefore,
It is possible to prevent the bump 3 and the aluminum electrode 11 from being damaged.

The material for forming the insulator layer 1 and the support 6 is not particularly limited as long as it is a film having electric insulation properties. Specifically, polyester resin, epoxy resin, urethane resin, polystyrene resin, polyethylene resin, polyamide resin, polyimide resin,
Examples thereof include thermosetting resins or thermoplastic resins such as acrylonitrile-butadiene-styrene (ABS) copolymer resin, polycarbonate resin, silicone resin, and fluorine resin, and among these, excellent heat resistance and mechanical strength. In addition, a polyimide resin is particularly preferably used because it can be matched with the coefficient of linear expansion of the test object.

The thickness of the insulator layer 1 is not particularly limited, but it is preferably set to 2 to 500 μm, preferably 10 to 150 μm in order to have sufficient mechanical strength and flexibility. Further, the thickness of the support 6 is 5 to 200 μm in order to have sufficient mechanical strength.
m, preferably 25 to 100 μm.

The constituent material of the adhesive layer 5 is, for example, an epoxy resin or an alkaline resin, and the thickness of the adhesive layer 5 is 5 to 200 μm, preferably 20 to 100 μm.
It is preferable to set to.

The forming material for forming the leads 2, the bumps 3, and the conductive paths 4 which are circuit wirings is not particularly limited as long as it has conductivity, and known metal materials can be used. For example, gold or silver. , Copper, platinum, lead, tin, nickel,
Examples include single metals such as cobalt, indium, rhodium, chromium, tungsten, and ruthenium, or various alloys containing these as components, such as solder, nickel-tin, and gold-cobalt. A metal that is hard and difficult to oxidize and has a low electric resistance, such as an oxide layer on the aluminum electrode 11 which is a terminal of the device under test or an insulating layer on the wiring pattern, is usually used. Noble metals such as rhodium, ruthenium and platinum are preferably used.

The thickness of the lead 2 which is the circuit wiring is not particularly limited, but is 1 to 200 μm, preferably 5 to 80 μm.
It is preferable to set to m.

The height of the bump 3 from the surface 1b of the insulator layer 1 is not particularly limited, but is preferably 0.1 μm to several hundreds μm. The bump 3 is formed in a hemispherical shape in addition to the mushroom shape (umbrella shape) as shown in FIG. The shape of the bump 3 may be a triangle, a quadrangle, or a circle. When the bottom shape is a circle, the entire shape formed may be a hemisphere or a cylinder, and can be arbitrarily designed according to the layout of the object to be inspected.

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 different substances, but normally the same substance is used, and in this case, the bumps 3 and the conducting paths 4 are integrally formed. Is preferred for production.

FIG. 2 is a sectional view showing another embodiment of the probe structure of the present invention, which is the probe structure P2 of FIG.
As shown in, a structure using three types of forming materials may be used. That is, an inexpensive metal substance such as copper is used for the conductive path 4 connected to the lead 2, and gold or the like having high connection reliability is used for the surface layer 3a of the bump 3 that contacts the aluminum electrode 11 or the like. Then, the conduction path 4 and the surface layer 3a
Nickel or the like is used as the barrier metal substance for preventing the mutual reaction of the metal substances in the intermediate layer 3b interposed between and. Further, the structure is not limited to the above-mentioned three kinds of forming materials, and may be formed into a structure using four or more kinds of forming materials.

FIG. 3 is a sectional view showing another embodiment of the probe structure of the present invention. As shown in the probe structure P3 of FIG. 3, the bump 3 has a plurality of minute metal protrusions on its surface. The object 31 may be included. The metal protrusion 31 is
The bump 3 may be formed using a single metal or alloy different from the bump 3. In general, inexpensive nickel or copper having excellent conductivity is preferably used as the material for forming the bumps 3, whereas the material for forming the metal protrusions 31 is an oxide layer or wiring on the aluminum electrode 11. Hard and difficult to oxidize so that the insulating layer on the pattern can be destroyed,
Further, a metal having a low electric resistance, for example, a noble metal such as rhodium, ruthenium or platinum is preferably used.

Mutual reaction between the bump 3 and the metal protrusion 31.
When the response occurs, each changes the physical properties of the metal, so
In order to maintain the physical properties, the bump 3 and the metal protrusion 31
It is preferable to apply a barrier metal between them. For example, gold and copper
When diffusion occurs like a combination of
Then, nickel is preferably applied between gold and copper. Na
By using a single metal, the bumps 3 and the metal bumps can be plated.
When it forms with the product 31, it has a hydrogen embrittlement property and a sulfur embrittlement property.
Plating conditions that make the metal more brittle are not preferred.
For example, using nickel sulfamate plating solution
As a brightener for nickel plating liquid, saccharin or naphth
Sulfur-containing additives such as sodium talin sulfonate
Nickel metal formed by using or using is a pure metal.
Axel and Ni ₃S₂It is a eutectic of the intermetallic compound of
When heated by treatment, this Ni₃S₂Intermetallic compound
Objects gather and become brittle.

By forming the minute metal protrusions 31 on the surfaces of the bumps 3 as described above, it becomes easy to destroy, for example, the oxide layer on the aluminum electrode 11 or the insulating layer on the wiring pattern. Since there are a plurality of contact points between the bumps 3 and the bumps 11, a reliable continuity test can be performed.

FIG. 4 is a cross-sectional view showing another embodiment of the probe structure of the present invention. As shown in the probe structure P4 of FIG. 4, the insulating layer 1 on the side where the bumps 3 are formed is shown. The protective resin layer 7 may be formed on the surface 1b.
The protective resin layer 7 is usually 5 to 50 μm, preferably 10
The protective resin is provided with a thickness of ˜30 μm, and a thermosetting resin such as an epoxy resin or a thermoplastic resin such as a fluorine resin is used as the protective resin.

In FIG. 4, the protective resin layer 7 is provided in advance on the surface of the insulator layer 1 and then the bumps 3 are formed. After the bumps 3 are formed, a protective resin layer in the form of a film or ribbon is formed. 7 may be thermocompression bonded, or a protective resin may be formed by extrusion molding, casting coating, or the like.
In this case, it is necessary to prevent the bump 3 and the metal protrusion 31 from being completely covered with the protective resin layer 7.

With this structure, it is possible to prevent damage to the object to be inspected by the head portion when conducting the continuity inspection. Further, when the protective resin layer 7 is provided after forming the bumps 3, it is possible to further protect the bumps 3 and the metal protrusions 31 and prevent them from falling off.

FIG. 5 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. 5 (a), a laminate formed by laminating the insulator layer 1 and the conductive material layer 8 on the surface 1a of the insulator layer 1a by a known method. Prepare a base material. Examples of the method for forming the conductive material layer 8 on the surface of the insulator layer 1 include sputtering, various vapor depositions, various platings, and the like. In addition, a conductive foil is used as the conductive material layer 9 and the insulator layer 1 is laminated on the conductive foil, or an insulator is applied on the conductive foil and solidified to form the surface of the conductive material layer 8. A method of forming the insulating layer 1 may be mentioned.

Next, as shown in FIG. 5B, after forming a resist layer on the surface 8a of the conductive material layer 8 to insulate it, 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 8 is etched,
It is formed into a desired linear pattern.

Next, as shown in FIG. 5C, a through hole 9 reaching the lead 2 is formed obliquely in the insulator layer 1. The formation of the through hole 9 is important for achieving electrical connection between the lead 2 and the bump 3, and is provided in the region where the lead 2 of the insulator layer 1 abuts the insulator layer 1 or the region including the region. At least one fine through hole 9 is formed in the vicinity region at a hole pitch smaller than the width of the lead 2. The inclination of the through hole 9 is 30 ° or more and less than 90 ° with respect to the thickness direction of the insulating layer 1, and preferably 45 ° to 80 °.
Let be °. If the inclination of the through hole 9 is less than 30 °, the cushioning property becomes poor and the bump 3 or the aluminum electrode 1
It may not be possible to prevent the damage of 1.

The through holes 9 are formed by mechanical punching such as punching, plasma processing, laser processing, photolithography processing, or chemical etching using a resist having chemical resistance different from that of the insulating layer 1, fine pitch. In order to cope with this, 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, perforation processing by irradiation of excimer laser with controlled pulse number or energy amount is preferable. The hole diameter of the through hole 9 is 5 to 200 μm, preferably 8
Approximately 50 μm. In order to increase the number of through-holes 9 in contact with the leads 2, the through-holes 9 are formed so that the diameter of the through-holes 9 is increased to the extent that adjacent through-holes are not connected to each other and the pitch between the holes is made as small as possible. Conducting path 4
This is preferable in reducing the electric resistance of.

Next, as shown in FIG. 5D, a protective insulating layer 12 is formed on the surface 1a of the insulating layer 1 so as to cover the leads 2. After that, the through hole 9 is filled with a conductive material to form the conductive path 4 and the bump 3, the protective insulating layer 12 is removed by a conventional method, and the probe structure P1 is formed as shown in FIG. 5 (e). obtain.

The conductive paths 4 and the bumps 3 are formed by a method of physically embedding a conductive material in the through holes 9, CVD.
Method, a plating method such as electrolytic plating or electroless plating, a chemical method of precipitating a conductive substance by immersing the structure obtained by the above step in a molten bath of a conductive substance and pulling it up, The method of electrolytic plating using the lead 2 as an electrode is preferable because it is a simple method. In the present invention, the term “filling with a conductive substance” includes not only physical filling with a conductive substance but also the above-mentioned chemical deposition and the like, and a through hole for forming a tubular plating on the wall surface of the through hole 9. It is a broad concept that also includes plating.

In order to form the metal protrusion 31 as shown in FIG. 3, for example, the following method can be adopted.

First, after the bumps 3 are formed and before the metal protrusions 31 are formed, the metal powder is dispersed in the plating bath and electroplating is performed. By doing so, the metal powder adheres to the surface of the bump 3 and becomes a seed (nucleus) for plating growth, and the metal protrusion 31 is formed. The metal powder to be dispersed is preferably in the form of fine powder in order to form the fine metal protrusions 31, and the particle size is 0.01 to 2
00 μm, preferably 0.1 to 50 μm, further 1 to
The one having a thickness of about 3 μm is used.

Also, as shown in FIG.
Is preferably formed near the apex of the bump 3 from the viewpoint of increasing the number of contacts during the continuity test. In order to form in this way, it is preferable to apply a magnetic field in the apex direction of the bumps 3, that is, in the drilling direction of the through holes 9 to perform the electrolytic plating. The strength of the magnetic field at this time is about 1 kilogauss to 15 kilogauss, preferably about 2 kilogauss to 5 kilogauss. When electrolytic plating is performed by applying a magnetic field, a magnetic metal such as nickel or cobalt is used as the metal powder dispersed in the plating solution.

As another method, a plating solution in which metal powder is dispersed is sprayed onto the surface of the formed bump 3 by using a circulating pump or the like to form the metal protrusion 31 on the surface of the bump 3. There is a method of forming seeds.

Further, as another method, there is a method of performing electrolytic plating while applying ultrasonic waves to the plating bath. In this case, it is preferable to activate the surface of the bump 3 by etching or the like from the viewpoint of the formability of the metal protrusion 31.

A more specific production example of the probe structure of the present invention will be shown below. On a copper foil having a thickness of 35 μm, a polyimide precursor solution was applied so that the thickness after drying would be 25 μm, dried, and cured to obtain a copper foil and a polyimide film.
A layer film was prepared.

Next, after forming a resist layer on the surface of the copper foil to insulate it, a photo step was used to form a desired linear pattern.

Next, the surface of the polyimide film is irradiated with KrF excimer laser light having an oscillation wavelength of 248 nm from a direction of 45 ° with respect to the thickness direction of the polyimide film through a mask to perform dry etching, and the polyimide film is 60 μmφ in pitch 200 μm. A fine through hole having a depth of 25 μm was provided in an area of 8 cm ² at 5 holes / mm ² .

Next, a resist was coated on the surface of the copper foil, cured to insulate it, and immersed in a chemical polishing liquid at 50 ° C. for 2 minutes. After washing this with water, connect the copper foil to the electrode and
Immersed in the cyanide gold plating bath, the copper foil is used as a negative electrode to grow the gold plating in the through-hole part of the two-layer film, and when gold crystals project from the surface of the polyimide film (protrusion height about 5 μm), the plating treatment is performed. Suspended. Finally, the coated resist layer was peeled off to obtain the probe structure of the present invention.

[0047]

As described above, according to the probe structure of the present invention, since the contact portion and the circuit wiring are connected by the conductive path formed in the diagonal direction of the insulator layer, the contact portion and the covered wiring are covered. When the terminals of the inspection body are brought into contact with each other, the pressure applied to the terminals of the inspection object is decomposed, and the force applied in the vertical direction (thickness direction) of the terminals is reduced. Therefore, damage to the contact portion and the terminal can be prevented. In addition, the probe structure itself has a cushioning effect upon contact, and the stress can be sufficiently relaxed even when an external stress is applied, and the contact portion does not fall off from the insulating layer together with the conductive path.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a probe structure of the present invention.

FIG. 2 is a sectional view showing another embodiment of the probe structure of the present invention.

FIG. 3 is a sectional view showing another embodiment of the probe structure of the present invention.

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

FIG. 5 is a cross-sectional view showing the manufacturing process of the probe structure of the present invention.

[Explanation of symbols]

 1 Insulator Layer 1a Other Surface 1b One Surface 2 Lead (Circuit Wiring) 3 Bump (Contact Point) 4 Conduction Path 10 Semiconductor Element (Inspection Object) 11 Aluminum Electrode (Terminal) P1 Probe Structure

Front page continuation (72) Inventor Toshiki Naito 1-2 1-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto Denko Corporation

Claims (1)

[Claims] 1. A test device for conducting a continuity test of an object to be inspected is formed on one surface of an insulating layer, and a contact portion abutting a terminal of the object to be inspected is formed on the other surface of the insulating layer. A probe structure, in which circuit wiring to be connected is formed, and the contact portion and the circuit wiring are connected by a conductive path formed in an oblique direction of the insulator layer.