JPH06342011A - Probe structure and continuity inspection method - Google Patents

Abstract

(57) [Summary] [Structure] A circuit wiring 2 made of a conductive material is formed on one surface 11 of the insulating base material 1, and a rivet-shaped protruding electrode 3 is formed at one end of the circuit wiring 2. Has been formed. The circuit wiring 2 is connected to a tester (not shown), and when the projecting electrode 3 comes into contact with a circuit of a test object (not shown),
The tester conducts a continuity test of the device under test. A fine through hole 4 penetrating from one surface 11 to the other surface of the insulating substrate 1 is formed in a region of the insulating substrate 1 other than the region where the circuit wiring 2 is formed. [Effects] When conducting a continuity inspection of an object to be inspected, a tensile stress is applied to the probe structure P1 to stretch the insulating base material 1 and the contraction of the probe structure P1 can be corrected, and the dimensional accuracy of the circuit wiring 2 can be corrected. Is improved. In addition, mechanical elasticity (cushioning property) at the time of connection is increased, and connection reliability is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe structure and a continuity inspection method, and more particularly to a semiconductor device, a semiconductor device assembly such as a wafer on which a semiconductor device before dicing is formed,
A probe structure provided at the tip of a test device such as a tester used for a continuity inspection of a semiconductor device and a continuity inspection of a wiring circuit such as a circuit board for mounting a semiconductor device and an LCD circuit board, and this probe structure were used. The present invention relates to a method for inspecting continuity of a device under test such as the semiconductor element.

[0002]

2. Description of the Related Art Manufacturing of electric parts having a large number of terminals,
In an inspection process such as mounting an electronic component on a printed circuit board, measurement and inspection are performed such as electrical continuity between product terminals and voltage state of a predetermined test location. On the other hand, as electronic devices have become thinner, smaller and lighter in recent years, semiconductors have been highly integrated and highly packaged. With these developments, the number of electrodes of semiconductor devices has increased, and the pitch thereof has become narrower year by year.

Conventionally, a mechanical probe system has been adopted for conducting a continuity test of a semiconductor device or the like by bringing a needle-shaped metal terminal into contact with a pad of a chip. However, such a mechanical probe system is highly integrated. However, there is a limit to the continuity test of a semiconductor device having a high density, and development of a new probe has been desired.

Against this background, attention has recently been paid to an inspection probe in which a protruding electrode is formed on the circuit wiring of a flexible circuit board. Since the inspection probe can form the circuit pattern at a fine pitch, it is possible to accurately realize the positional relationship corresponding to the electrode pads of the chips arranged at the fine pitch.

The flexible circuit board is formed by forming a circuit on a two-layer base material in which an insulating film and a metal layer are integrated, or a three-layer base material adhered by an adhesive. Therefore, it is suitable for connecting electronic components mounted in high density.

However, year after year, the degree of integration of semiconductor devices has increased, the pitch of the electrode pads of the chip has become narrower, and the circuit pattern of the inspection probe needs to be further narrowed. Since the heat shrinks slightly (about 1% or less), the dimensional accuracy of the inspection probe is lowered, and it may not be possible to cope with a fine pitch. In addition, when the pattern pitch of the inspection probe is narrowed, the area occupied by the circuit pattern on the surface of the insulating film is increased, the mechanical elasticity (cushioning property) of the probe is reduced, and as a result, the connection reliability is reduced. is there.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and prevents the dimensional accuracy of a circuit pattern from decreasing due to thermal contraction of an insulating base material of a flexible circuit board. A probe structure capable of accommodating a finer pitch and providing a cushioning property to an electrode pad on a semiconductor element and an inspection probe when contacting the probe to improve connection reliability. It is an object of the present invention to provide a continuity inspection method using the same.

[0008]

Therefore, as a result of intensive studies to achieve the above object, the present inventors have found that a through hole is formed in the portion of the insulating base material where the circuit wiring of the flexible circuit board does not exist. By providing the substrate with mechanical stretchability by drilling, when conducting a continuity test of a semiconductor element,
It was found that the pattern pitch can be corrected by applying tensile stress to the base material. Further, by forming the through hole, it was found that when the electrode pad on the semiconductor element and the inspection probe are brought into contact with each other, the cushioning property of the probe is increased, and the connection reliability can be improved, The present invention has been completed.

That is, according to the probe structure of the present invention, the circuit wiring is formed on one surface of the insulating base material, and the insulating base material is provided in the area of the insulating base material other than the area where the circuit wiring is formed. Is characterized in that a through hole is formed in the thickness direction thereof.

In particular, the circuit wiring is characterized in that a metal protrusion is formed.

Further, a through hole is formed in the thickness direction of the insulating base material in a part of the region of the insulating base material where the circuit wiring is formed.

In the continuity inspection method of the present invention, the probe structure is stretched, the probe structure is connected to a test device for conducting continuity inspection, and then the circuit wiring or the metal protrusion of the probe structure is inspected. It is characterized by contacting the circuit of the body.

[0013]

According to the probe structure of the present invention, since the through hole is formed in the thickness direction of the insulating base material in the area of the insulating base material other than the area where the circuit wiring is formed, The elastic base material is provided with mechanical stretchability, and when the insulating base material is thermally shrunk, a tensile stress is applied to the insulating base material so that the pattern pitch of the circuit wiring can be evenly extended. The dimensional accuracy of wiring is improved. Further, since the gap is formed in the insulating base material by forming the through-hole, when the object to be inspected such as a semiconductor element and the probe are brought into contact with each other to conduct the continuity inspection of the object to be inspected. The mechanical elasticity (cushioning property) of the probe structure is increased, and the connection reliability is improved.

In particular, when a metal projection is formed on the circuit wiring, the connection between the metal projection and a device under test such as a semiconductor element is good, and the connection reliability is improved.

Furthermore, when a through hole is formed in the thickness direction of the insulating base material in a part of the area where the circuit wiring is formed, the circuit wiring exposed from the insulating base material through the through hole. Since the portion (1) can be a circuit (electrode) for contacting the circuit of the device under test, the step of forming the electrode on the circuit wiring can be omitted, which is advantageous in manufacturing.

Further, according to the continuity inspection method of the present invention, the probe structure is stretched, and the dimensions of the probe structure are finely adjusted so as to match the object to be inspected such as a semiconductor element, and the circuit wiring Since the pattern pitch is corrected, the circuit wiring of the probe structure or the metal protrusion accurately contacts the circuit of the device under test, and the reliability of the result of the continuity test by the test equipment is improved.

In the present invention, 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.
The "inspection object" refers to 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, and the like. "Circuit" means not only wiring patterns, but also electrodes (pads, terminals),
It is a broad concept that includes lead wires and the like. "Connecting" means that they are in electrical contact with each other. Furthermore, the shape of the “through hole” on the surface of the insulating substrate is not limited to a circle, and may be a triangle, a square, a rectangle, a trapezoid, a parallelogram, other polygons, an ellipse, or the like. The concept of "includes a slit continuous from one end to the other end of the insulating substrate.

[0018]

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 plan view showing an embodiment of the probe structure of the present invention, and FIG. 2 is a sectional view taken along the line AB of FIG. In the probe structure P1 shown in FIGS. 1 and 2, a circuit wiring 2 made of a conductive material is formed on one surface 11 of the insulating base material 1, and one end of the circuit wiring 2 has a rivet-like shape. A protruding electrode 3 which is a metal protrusion is formed. The circuit wiring 2 is connected to a tester (not shown), and when the protruding electrode 3 contacts a circuit of the test object (not shown), the tester conducts a continuity test of the test object. In this example, it should be noted that the insulating base material 1
A fine through hole 4 penetrating from one surface 11 to the other surface 22 of the insulating substrate 1 is formed in a region N other than the region where the circuit wiring 2 is formed.

The material of the insulative base material 1 has electrical insulation properties, and is preferably a material having a small elongation among the mechanical properties. Specifically, polyester resin, epoxy resin, urethane resin, polystyrene resin, polyethylene resin, polyamide resin, polyimide resin,
A thermosetting resin or a thermoplastic resin such as an acrylonitrile-butadiene-styrene (ABS) copolymer resin, a polycarbonate-based resin, or a silicone-based resin may be mentioned.
Of these, a polyimide resin having excellent heat resistance and mechanical strength is particularly preferably used. Further, it is known that ablation by an excimer laser is effective as a method for precisely processing a polymer, but it is preferable to use a polyimide resin in adopting this method.

The insulating base material 1 is preferably made of a material having a small elongation, and the expansion / contraction% when affected by moisture absorption and drying at room temperature.
2% or less, preferably 0.5% or less is used. Note that the above-mentioned expansion / contraction% also includes elongation due to tension when the tape is roll-conveyed.

The thickness of the insulating base material 1 is not particularly limited, but preferably has sufficient mechanical strength and flexibility, and is preferably set to 5 to 150 μm, particularly 10 to 100 μm.

The conductive material forming the circuit wiring 2 is not particularly limited as long as it has conductivity, and known metal materials can be used. For example, gold, silver, copper, platinum,
Lead, tin, nickel, cobalt, indium, rhodium,
Examples include single metals such as chromium, tungsten, and ruthenium, or various alloys containing these, for example, conductive materials such as solder, nickel-tin, and gold-cobalt. The circuit wiring 2 is a circuit formed by etching a layer made of a conductive material formed on the insulating base material 1 to form a desired linear pattern, and is electrically connected to the circuit of the device under test. .

The height of the bump electrode 3 is not particularly limited, but is preferably several microns to several tens of microns. In addition to the rivet shape shown in FIG. 1, the protruding electrode 3 is formed in a hemispherical shape, a mushroom shape (umbrella shape), or the like. As the conductive material forming the protruding electrodes 3, the same conductive material forming the circuit wiring 2 can be used.

The diameter of the fine through holes 4 (hole diameter) is usually 5
To 100 μm, preferably 10 to 50 μm, and the pitch is 5 to 200 μm, preferably 10 to 100 μm. Further, the open area ratio on the surface of the insulating base material 1 (including the area where the circuit wiring 2 is formed) is 30 to 60%, preferably 40 to 50%.

Another embodiment of the probe structure of the present invention will be shown below. 1 and 2 in the following examples.
The parts to which the same reference numerals are attached indicate the same or corresponding parts.

FIG. 3 is a plan view showing another embodiment of the probe structure of the present invention, and FIG. 4 is a sectional view taken along the line CD of FIG. It should be noted that in the probe structure P2 shown in FIGS. 3 and 4, in the region N of the insulating base material 1 other than the area where the circuit wiring 2 is formed, one surface 11 to the other surface of the insulating base material 1 is used. The point is that a through groove 5 that penetrates up to 12 is provided. The width of the through groove 5 is usually 5 to 100 μm.
m, preferably 10 to 50 μm, and the length is usually 1
The thickness is from 00 to 1000 μm, preferably from 200 to 500 μm. According to the present embodiment, even if the ratio of the area where the circuit wiring 2 is formed to the surface of the insulating base material 1 is large, the open area ratio can be set within the above range.

FIG. 5 is a plan view showing another embodiment of the probe structure of the present invention, and FIG. 6 is a sectional view taken along the line EF of FIG. It should be noted that in the probe structure P3 shown in FIGS. 5 and 6, from the one surface 11 to the other surface 12 of the insulating substrate 1 in a part of the region of the insulating substrate 1 where the circuit wiring 2 is formed. The point is that a through hole 6 is formed so as to penetrate therethrough and a part 7 of the circuit wiring 2 is exposed. According to the present embodiment, the exposed portion 7 of the circuit wiring 2 becomes a circuit (electrode) for contacting the circuit of the device under test, and the step of forming the protruding electrode 3 on the circuit wiring 2 can be omitted. Is advantageous in manufacturing.

FIG. 7 is a plan view showing another embodiment of the probe structure of the present invention, and FIG. 8 is a sectional view taken along the line GH of FIG. Notable in the probe structure P4 shown in FIGS. 7 and 8 is the slit 8 crossing the insulating substrate 1.
Is formed and a part 7 of the circuit wiring 2 is exposed. According to the present embodiment, as described above, the step of forming the protruding electrode 3 on the circuit wiring 2 can be omitted, and further, as in the embodiments of FIGS. 5 and 6, a part 7 of the circuit wiring 2 can be omitted. In order to expose the
Since it is not necessary to selectively perforate a part of the insulating base material 1, the productivity is further improved.

FIG. 9 is a cross-sectional view showing the manufacturing process of the probe structure of the present invention, which can be manufactured, for example, as follows.

First, as shown in FIG. 9A, a laminated base material formed by laminating an insulating base material 1 and a conductive material layer 9 is prepared. Examples of the method of forming the conductive material layer 9 on the surface of the insulating base material 1 include a plating method, a sputtering method, a CVD method and the like. In addition, the conductive material layer 9
A conductive foil is used as the insulating base material, and the insulating base material 1 is laminated on the conductive foil, or an insulating material is applied on the conductive foil and solidified to form an insulating base material on the surface of the conductive material layer 9. 1
And a method of forming. The laminated base material is not limited to a two-layered base material in which the insulating base material 1 and the conductive material layer 9 are directly stacked, and for example, an adhesive layer is provided between the insulating base material 1 and the conductive material layer 9. It may be a three-layered base material via.

Next, as shown in FIG. 9B, a resist layer 10 is formed on the surface of the conductive material layer 9 to insulate it, and then the photolithography process is used to perform chemical etching to form the protruding electrode 3. The resist is removed at the position where the conductive material layer 9 is to be formed, and a hole 20 is formed to expose a part of the conductive material layer 9.

Next, as shown in FIG. 9C, the holes 20 are filled with a conductive material to form the protruding electrodes 3. The protruding electrodes 3 are formed by physically embedding a conductive material in the holes 20, a CVD method, a plating method such as electrolytic plating or electroless plating, and a structure obtained by the above-mentioned steps in a conductive material melting bath. It can be performed by a chemical method such as immersing in and pulling up to deposit a conductive substance. Therefore, in the present invention, the filling of the conductive substance is a broad concept including not only the physical filling of the conductive substance but also the above-mentioned chemical deposition. In addition, in consideration of the connection reliability, if necessary, the protruding electrode 3
It is preferable to plate gold, silver, solder or the like.

Further, as shown in FIG. 9D, after the remaining resist layer 10 is removed, the circuit wiring diagram is projected again using the photo process, and the circuit is etched by chemical etching or electrolytic corrosion. The wiring 2 is formed. In addition,
The formation of the protruding electrode 3 may be performed after the circuit wiring 2 is formed.

Next, a plurality of fine through holes 4 are formed in the thickness direction in the region N of the insulating base material 1 other than the region where the circuit wiring 2 is formed to obtain the probe structure P1. Fine through hole 4
In order to correspond to the mechanical punching method 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, and fine pitching. Can be performed by a method such as laser processing capable of fine processing, and among them, opening processing by irradiation of an excimer laser with controlled pulse number or energy amount is preferable. In particular, an ultraviolet laser having an oscillation wavelength of 400 nm or less, which does not damage the insulating base material 1 and has a very sharp processed cross section, is suitable. The through groove 5, the through hole 6 and the slit 8 shown in FIGS. 3 to 8 can also be formed in the same manner as the fine through hole 4.

The probe structure P3 shown in FIGS.
In P4, it is not necessary to form the protruding electrode 3, the step of FIG. 9B can be omitted, and the through hole 6 or the slit 8 can be formed at the same time when the fine through hole 4 is formed. Therefore, it is advantageous in manufacturing and high in productivity.

Hereinafter, more specific production examples of the probe structure of the present invention will be shown.

Polyamic acid was applied onto a copper foil having a thickness of 35 μm, dried and cured to form a polyimide layer having a thickness of 13 μm, to prepare a two-layer base material of a copper foil and a polyimide film.

Next, a resist was applied to the surface of the copper foil and cured except for the portion where the bump electrode was formed, and then immersed in a chemical polishing liquid at 50 ° C. for 2 minutes. After washing these with water, connect the copper foil part to the electrode and immerse it in a gold cyanide plating bath at 60 ° C to grow the gold plating in the hole drilled in the resist layer with the copper foil as the negative electrode. The plating process is interrupted when the metal grows to a height of about 15 μm,
A protruding electrode was formed.

Next, the coated resist layer was peeled off, the resist was again coated on the surface of the copper foil, the circuit wiring diagram was projected and cured, and then immersed in a chemical polishing liquid at 50 ° C. for 2 minutes. . After washing these with water, the copper foil of the two-layer substrate was dissolved and removed with cupric chloride.

Next, the surface of the polyimide film is irradiated with KrF excimer laser light having an oscillation wavelength of 248 nm through a mask to perform dry etching, and fine through holes with a pitch of 25 μm and a pitch of 50 μm are formed in the polyimide film other than the region where the circuit pattern is formed. Drilled.

FIG. 10 is a sectional view showing the continuity inspection method of the present invention. When conducting the continuity inspection of the semiconductor device 30 as the device under test, tensile stress is applied to the probe structure P1 so that the surface area of the insulating base material 1 is 1% or less (usually 0.4 to
The expansion is increased by about 0.5%), and the contraction of the probe structure P1 is corrected in order to align the electrode 31 of the semiconductor element 30 and the protruding electrode 3 of the probe structure P1.
The expanded circuit wiring 2 of the probe structure P1 is also connected to a tester (not shown) via an external connection electrode (not shown), and the protruding electrode 3 formed on the circuit wiring 2 is electrically connected to the tester. .

After arranging the protruding electrode 3 of the probe structure P1 and the electrode 31 of the semiconductor element 30 so as to face each other, the probe structure P1 and / or the semiconductor element 30 are displaced so as to approach each other, and the protruding electrode 3 is formed. And the electrode 31 are brought into contact with each other. A signal of a specific frequency for conducting the continuity test of the circuit of the semiconductor element 30 is input from the tester to the electrode 31 of the semiconductor element 30 via the protruding electrode 3 to conduct the continuity test of the semiconductor element 30. 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-described operation is repeated in order to conduct a new semiconductor element continuity test.

The probe structure of the present invention is used for the continuity inspection of semiconductor elements as described above, the conduction inspection of anisotropic conductors for mounting semiconductor elements, liquid crystal display elements, etc., the inspection of printed wiring boards, flexible boards, Or hybrid I
It can also be used for connection or inspection between fine pitch circuits such as C.

[0045]

According to the probe structure of the present invention, even when the pattern pitch of the circuit wiring formed on the insulating base material is contracted by heat, the tensile stress is applied to the insulating base material, thereby the circuit wiring You can correct the pattern pitch,
The dimensional accuracy of circuit wiring is improved. In addition, when contacting with an object to be inspected such as a semiconductor element to conduct a continuity inspection of the object to be inspected, mechanical elasticity (cushioning property) at the time of connection increases, and connection reliability improves.

According to the continuity inspection method of the present invention, the circuit wiring or the metal protrusion of the probe structure accurately contacts the circuit of the object to be inspected, and the reliability of the result of the continuity inspection by the test equipment is improved.

[Brief description of drawings]

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

FIG. 2 is a sectional view taken along the line AB of FIG.

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

FIG. 4 is a cross-sectional view taken along the line CD of FIG.

FIG. 5 is a plan view showing another embodiment of the probe structure of the present invention.

6 is a cross-sectional view taken along the line EF of FIG.

FIG. 7 is a plan view showing another embodiment of the probe structure of the present invention.

8 is a cross-sectional view taken along the line GH in FIG.

FIG. 9 is a cross-sectional view showing the manufacturing process of the probe structure of the present invention.

FIG. 10 is a cross-sectional view showing the continuity inspection method of the present invention.

[Explanation of symbols]

 1 Insulating Base Material 2 Circuit Wiring 3 Projection Electrode 4 Micro Through Hole 5 Through Groove 6 Through Hole 8 Slit

Claims (4)

[Claims] 1. A circuit wiring is formed on one surface of an insulating base material, and a through hole is formed in a thickness direction of the insulating base material in a region of the insulating base material other than a region where the circuit wiring is formed. A probe structure characterized by being drilled. 2. The probe structure according to claim 1, wherein metal protrusions are formed on the circuit wiring. 3. A through hole is formed in a part of a region of the insulating base material where the circuit wiring is formed in a thickness direction of the insulating base material. Probe structure. 4. The circuit structure or the metal protrusion of the probe structure is inspected after the probe structure according to any one of claims 1 to 3 is stretched and the probe structure is connected to a test device for conducting a continuity test. A continuity test method characterized by bringing into contact with a circuit of a body.