JPH06265575A - Fabrication of probe head - Google Patents

Abstract

PURPOSE:To obtain a highly accurate, high density, multiterminal probe head by bonding contact electrodes of a circuit pattern corresponding to LSI electrode pads to conductive rubber contactors having one end applied with a metal film through an adhesive. CONSTITUTION:A resist layer 12 is formed on a bored copper foil 11 and then exposed and developed using the hole to make a hole 13 through the foil 11 and the layer 12 thus forming a film substrate 14. The hole 13 is then filled with a conductive rubber which is subsequently hardened to form a conductive rubber contactor 4. A metal film is adhered thereto by means of plating or the like. The layer 12 is then peeled off such that the contactor 4 projects from at least one plane of the substrate 14. A circuit pattern including contact electrodes 3 previously provided on the substrate 2 while corresponding to the LSI electrode pads is pressure bonded through an organic adhesive 5 while aligning the contact electrodes 3 formed on the circuit board by thin film forming technology with the contactors 4. Subsequently, the foil 11 is removed by etching thus completing a probe head 1.

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, and more particularly, to a method of manufacturing a probe head used in an LSI inspection apparatus which is compatible with high density and multiple terminals.

[0002]

2. Description of the Related Art In recent years, the electrodes of LSIs have become narrower in pitch as shown in ASICs, liquid crystal driving LSIs, etc., and the number of electrodes has been increased. In the near future, it is expected that the pitch will become narrower and the number of electrodes will increase. When electrically measuring such a narrow-pitch, multi-electrode LSI, a method of manufacturing a probe head that makes contact with the LSI electrode has become a serious problem.

On the other hand, as seen in the memory LSI, the memory capacity is being increased, and the lengthening of the measurement time accompanying the increase of the memory capacity leads to an increase in the occupying time of the measuring device and the measurement cost. However, in order to solve this problem, a large number of LSI
Attempts are being made to simultaneously measure chips and reduce the time occupied by the measuring device. However, many such LSIs
In order to simultaneously measure the chips, a multi-terminal probe head arranged in a matrix is required.

As described above, in order to further reduce the pitch, the number of electrodes, and the capacity of LSIs in the future, a technique for manufacturing a probe head having a high density and a large number of terminals is an important issue.

The structure of a conventionally used probe head for an LSI inspection device will be described with reference to FIG.

In FIG. 6, a predetermined circuit pattern 53 is formed on a printed circuit board 52 such as a copper-clad laminated board, and the printed circuit board 52 has an opening 54 for positioning at a position corresponding to the LSI electrode chip to be measured. Is provided. Further, the probe needle 55 made of a thin needle such as tungsten is supported by the support body 56 made of an elastic material and fixed to the printed circuit board 52. One end of the probe needle 55 is positioned corresponding to the electrode pad of the LSI, and the other end of the probe needle 55 is positioned at the printed circuit board 52.
Is connected to the circuit pattern 53 by soldering or the like. In this way, the probe head 51 was formed.

[0007]

However, in the probe head of the conventional example, the probe needle 55 made of a fine needle such as tungsten has the support 56 and the printed circuit board 52 provided at a position apart from the LSI electrode pad. Because of the structure in which the probe needle 55 is positioned and supported by the connection at the circuit pattern 53, the implantation accuracy of the probe needle 55 has a variation of about ± 10 to 20 μm in the plane direction and a variation of about ± 50 μm in the height direction. . When such a probe head 51 is used to make contact with an LSI electrode pad to measure an LSI, the height of the probe needle 55 may vary and the probe head 51 may be tilted when the LSI is attached.
In order to contact all the terminals of the electrode pad, it is necessary to overdrive the probe head 51. Also,
Since the electrode pad of the LSI is made of aluminum, an oxide film is formed on the surface thereof, and it is necessary to break the oxide film to make contact in order to make a stable contact. Overdrive will be applied. This overdrive causes the probe needle 55 to slip on the surface of the LSI electrode pad, and the slip of the probe needle 55 destroys the passivation film made of silicon nitride, phosphosilicate glass, polyimide, etc. around the LSI electrode pad, or near the LSI electrode pad. It has problems such as damage to the provided element region.

Furthermore, particularly the recent narrow pitch, multi-electrode LS
In I, the effective electrode size is 60 to 80 μm, the electrode pitch is less than 100 μm, and the size thereof is steadily shrinking. In the conventional probe head structure, the multi-terminal probe needle 55 is placed on a flat surface and a However, it was not possible to plant it accurately, and future narrow pitch, multi-terminal LS
There were many problems such as not being able to deal with the measurement of I.

Therefore, an object of the present invention is to solve the above-mentioned problems and to provide a method of manufacturing a probe head having high density and multiple terminals and high accuracy.

[0010]

In order to achieve such an object, a method of manufacturing a probe head according to the present invention has a metal layer and an organic layer formed on at least one surface of the metal layer, and further comprises: A step of forming a film substrate having a through hole penetrating the metal layer and the organic layer; a step of filling a conductive rubber into the through hole and forming a conductive rubber contact by curing the conductive rubber; Forming a metal film on one end of the conductive rubber contact and removing the organic layer or the metal layer so that the conductive rubber contact protrudes from at least one surface of the organic layer or the metal layer. Step, the contact electrode of the circuit pattern including the contact electrode provided corresponding to the LSI electrode pad is aligned with the conductive rubber contactor, and the contact electrode and the conductive rubber contact are made with an adhesive. A step of bonding the door, characterized in that it comprises a step of removing the metal layer.

As the metal film in the present invention,
A metal film of gold, silver, copper, aluminum, nickel or the like can be used, and a metal foil of copper, aluminum, nickel, stainless steel or the like can be used as the metal layer.

As the conductive rubber, nickel, iron,
It is possible to use conductive particles obtained by coating carbon, nickel, iron or the like with gold plating, or conductive short fibers dispersed in a binder such as silicone rubber, urethane rubber or styrene butadiene rubber.

Further, as the adhesive, an organic organic material having elasticity is preferable, and an adhesive made of silicone resin, epoxy resin, urethane resin or the like can be mentioned.

The conductive rubber and the adhesive are preferably made of the same material in terms of adhesion and the like, and more preferably the conductive rubber is a silicone rubber and the adhesive is a silicone resin in terms of heat resistance.

[0015]

According to the present invention, since photolithography is mainly used, it is possible to easily perform fine processing,
By appropriately selecting the thicknesses of the metal layer such as copper foil and the organic layer such as resist, the diameter and height of the conductive rubber contact can be widely selected.

Further, according to the present invention, it is possible to form minute conductive rubber contacts, and it is possible to fabricate a probe head having a high density and multiple terminals. Further, according to the present invention, since the metal film is formed on the tip, the metal oxide film on the LSI electrode butt is more easily broken than the structure including only the conductive rubber contactor, and the surface of the conductive rubber contactor is more easily broken. It is possible to suppress the conductive particles that fall off from the conductive rubber contactor, which improves the durability of the conductive rubber contact.

[0017]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a sectional view showing the structure of a probe head to which the present invention is applied.

In the figure, reference numeral 2 is a base substrate made of glass, ceramic, copper-clad laminate, or the like. A single-layer or multi-layer circuit pattern is formed on the base substrate 2 by a thin film forming method, an additive forming method, a subtractive forming method, or the like. At least the uppermost layer of this circuit pattern has contact electrodes 3 at positions corresponding to the LSI electrode pads. Are arranged. Further, a conductive rubber contact 4 is formed on the contact electrode 3. Further, the entire surface of the base substrate 2 except the top 6 of the conductive rubber contact 4 is covered with an organic adhesive 5 for protecting the circuit pattern.

The organic adhesive 5 also serves to reinforce the conductive rubber contact 4. The probe head 1 is formed in this way.

(Embodiment 1) FIG. 2 is a step showing a first embodiment of a method for manufacturing the probe head 1.

Holes are formed in the copper foil 11 at positions corresponding to the LSI electrode pads by methods such as photolithography, etching, and laser processing. A resist layer 12 is formed by pasting or coating a film-like or liquid positive resist on the copper foil 11 on which the holes have been formed. The copper foil 1 is exposed and developed by self-alignment using the holes formed in the copper foil 11.
1. Form a through hole 13 penetrating the resist layer 12. A film substrate 14 including a copper foil 11 having a through hole 13 and a resist layer 12 is formed (FIG. 2A).

Next, conductive rubber is filled in the through hole 13 and cured to form the conductive rubber contact 4 (FIG. 2B).

Next, a metal film is deposited on the formed conductive rubber contact 4 by a method such as a plating method, an electrodeposition method, an evaporation method or a sputtering method, and then the conductive rubber contact 4 is formed. It is formed on top (FIG. 2 (c)).

Next, the resist layer 12 is peeled and removed, and the conductive rubber contact 4 is formed so as to project from at least one surface of the film substrate 14 (FIG. 2D).

Next, a circuit pattern including a contact electrode 3 provided in advance on the base substrate 2 corresponding to the LSI electrode pad is accurately formed by a thin film forming method or an additive plating forming method. 3 and the conductive rubber contactor 4 of the film substrate 14 are positioned by pressure bonding with an organic adhesive 5 to integrate the circuit substrate and the film substrate 14 (FIG. 2 (e)).

Thereafter, the copper foil 11 is removed by etching to manufacture the probe head 1 (see FIG. 2).
(F)).

In the above steps, the resist layer 12 was described using a positive type resist, but in the same step, a layer may be formed by using a negative type resist or another organic resin material instead of the positive type resist. Is possible, in this case
Hole processing is performed by means such as dry etching.

(Embodiment 2) FIG. 3 is a process drawing showing a second embodiment of the method for manufacturing a probe head according to the present invention. Resist layers 22 are formed on both surfaces of the copper foil 21, and holes are formed in the resist layers 22 at positions corresponding to the LSI electrode pads by exposure and development. Next, the resist layer 22
Is used as a mask to etch the copper foil 21,
A through hole 23 penetrating the resist layer 22 is formed. Thus, the copper foil 21 having the through holes 23 and the resist layer 22
To form a film substrate 24 (FIG. 3).
(A)).

Next, the through hole 23 is filled with conductive rubber and cured to form the conductive rubber contact 4 (FIG. 3).
(B)).

Next, a metal film is deposited on the formed conductive rubber contact 4 by a method such as a plating method, an electrodeposition method, an evaporation method or a sputtering method, and then the conductive rubber contact 4 is formed. It is formed on the top (FIG. 3C).

Further, the resist layers 22 formed on both surfaces of the copper foil 21 are peeled and removed to form the conductive rubber contact 4 in which the conductive rubber contact 4 projects from at least one surface of the film substrate 24 (FIG. 3 (d). )).

Next, the conductive rubber contact 4 of the film substrate 24 and the contact electrode 3 are placed on a circuit substrate on which a circuit pattern including the contact electrode 3 is previously formed on the base substrate 2 by a thin film method or an additive plating method. The circuit board and the film board are integrated by pressure contact adhesion with the organic adhesive 5 as if positioning (FIG. 3 (e)).

Then, the copper foil 11 is etched to fabricate the probe head 1 (FIG. 3 (f)).

(Embodiment 3) FIG. 4 is a process diagram showing a third embodiment of the method for manufacturing a probe head according to the present invention. Both sides of the resist layer 32 are laminated with a copper foil 31 that has been subjected to hole processing by photolithography and etching at a position corresponding to the LSI electrode pad, and the resist layer 32 is etched using the holes formed in the copper foil 31 as a mask. By doing so, the through hole 3 penetrating the copper foil 31 and the resist layer 32
3 forming a copper foil 31 having a through hole 33 and a resist layer 3
2 to form a film substrate 34 (see FIG. 4).
(A)).

Next, a conductive rubber contact 4 is formed by filling the through hole with conductive rubber and curing it.
(B)).

Next, a metal film is deposited on the formed conductive rubber contact 4 by a method such as a plating method, an electrodeposition method, an evaporation method or a sputtering method, and then the conductive rubber contact 4 is attached. Formed on top (FIG. 4 (c)).

Next, the copper foils 31 on both surfaces of the resist layer 32 are removed by etching, and the conductive rubber contacts 4 are projected from at least one surface of the film substrate (FIG. 4 (d)).

Next, the conductive rubber contact 4 of the film is formed on the circuit board in which the circuit pattern including the contact electrodes 3 is formed on the base board 2 in advance by the thin film method and the additive plating method.
The circuit board and the film substrate are integrated with each other by pressing and adhering with the organic adhesive 5 so as to position the contact electrode 3 and the contact electrode 3 (FIG. 4E).

Thereafter, the resist layer 32 is peeled and removed to manufacture the probe head 1 (FIG. 4).
(F)).

(Embodiment 4) FIG. 5 is a process drawing showing a fourth embodiment of the method for manufacturing a probe head of the present invention.

An organic resist layer or film 42 such as a thin plate of polyimide, polyester, epoxy containing glass cloth, or the like is covered with a copper foil 41, and photolithography,
A hole is formed in the copper foil 41 at a position corresponding to the LSI electrode pad by a method such as etching. A film substrate 44 having a through hole 43 penetrating the copper foil 41 and the resist layer or film 42 is formed by boring the resist layer or film 42 by a method such as wet etching or dry etching using the hole-processed copper foil 41 as a mask. (Fig. 5)
(A)).

Next, conductive rubber is filled in the through hole 43 and cured to form the conductive rubber contact 4 (FIG. 5B).

Next, after depositing a metal film on the formed conductive rubber contact 4 by a method such as plating, electrodeposition, vapor deposition, sputtering, etc., the conductive rubber contact 4 is formed. Formed on top (FIG. 5 (c)).

Next, the copper foil 41 is removed by etching to form a film having conductive rubber contacts 4 which project on both sides of the resist layer 42 (FIG. 5 (d)).

Next, the contact electrode of the circuit board in which the circuit pattern including the contact electrode 3 provided in advance on the base substrate 2 corresponding to the LSI electrode pad is accurately formed by the thin film forming method or the additive plating forming method. 3 and the conductive rubber contact 4 of the film substrate 44 are positioned by pressure bonding with an organic adhesive 45 so that the circuit board and the film substrate 44 are integrated to produce the probe head 1 (FIG. 5 (e)).

In the first to fourth embodiments, the conductive rubber contact 4 has been described as a conductive rubber. However, nickel, iron or magnetic conductive particles or magnetic conductive short fibers plated with gold on nickel or iron, silicone rubber, urethane rubber or the like is used. By filling the holes in the film substrate with conductive rubber dispersed in the binder, and curing it while applying a magnetic field in the thickness direction of the film substrate, it has anisotropic conductivity showing unidirectional conductivity. The conductive rubber contact 4 can also be used.

Further, in the above-mentioned first to fourth embodiments, the processing of the through holes has been described by etching, but when the LSI electrode pad pitch exceeds 250 μm, it is about 100 μm or less, 30 μm by drilling. Up to this, it is also possible to form the through hole in the film substrate by laser processing.

[0049]

As described above, according to the present invention,
Since photolithography is mainly used, microfabrication can be easily performed, and the diameter and height of the conductive rubber contact can be widely selected by appropriately selecting the thickness of the metal layer and the organic layer. You can

Further, according to the present invention, it is possible to form a conductive rubber contactor having a minute metal film, and it is possible to manufacture a probe head having high density and multiple terminals.

For example, when the thickness of the metal layer is 35 μm and the thickness of the organic layer is 25 μm, the diameter of the conductive rubber contact is about 30 to 40 μm and the height of the conductive rubber contact is 6 μm.
A conductive rubber contact of about 0 μm can be formed.
In that case, the pitch is less than 100 μm.

Further, according to the present invention, it is possible to form a contact group corresponding to a relatively large area, and not only to cope with 1-chip level LSI measurement, but also to a wafer-level multi-chip. It is also possible to form a probe head capable of simultaneously measuring This means that it is possible to simultaneously measure VLSIs in future narrow pitch, multi-terminal LSIs and large-capacity memory LSIs.

Furthermore, according to the present invention, since the contact point with the LSI electrode pad is formed of a conductive rubber having a metal film, the contact pressure is dispersed by the elasticity of the rubber,
The yield at the time of measuring the LSI can be improved without damaging the LSI electrode, the passivation film near the LSI electrode, and the element region.

[Brief description of drawings]

FIG. 1 is a sectional view showing a structure of a probe head to which the present invention is applied.

FIG. 2 is a process drawing showing a first embodiment of the method of manufacturing a probe head of the present invention.

FIG. 3 is a process drawing showing a second embodiment of the method of manufacturing a probe head of the present invention.

FIG. 4 is a process drawing showing a third embodiment of the method of manufacturing a probe head of the present invention.

FIG. 5 is a process drawing showing a fourth embodiment of the method for manufacturing a probe head of the present invention.

FIG. 6 is a sectional view showing the structure of a conventional probe head.

[Explanation of symbols]

 1,51 probe head 2 base substrate 3 contact electrode 4 conductive rubber contactor 5,45 organic adhesive 6 metal coating 11,21,31,41 copper foil 12,22,32 resist layer 13,23,33,43 penetrating Hole 14, 24, 34, 44 Film substrate 42 Resist layer or film 52 Printed circuit board 53 Circuit pattern 54 Opening 55 Probe needle 56 Support

Claims (1)

[Claims] 1. A step of forming a film substrate having a metal layer and an organic layer formed on at least one surface of the metal layer, and further having a through hole penetrating the metal layer and the organic layer; Filling the holes with conductive rubber and forming a conductive rubber contact by curing the conductive rubber; forming a metal film at one end of the conductive rubber; removing the organic layer or the metal layer. A step of forming the conductive rubber contact so as to protrude from at least one surface of the organic layer or the metal layer, and a contact electrode of a circuit pattern including a contact electrode provided corresponding to an LSI electrode pad and the conductive material. A method of manufacturing a probe head, comprising: a step of aligning a rubber contact with each other and adhering the contact electrode and the conductive rubber contact with an adhesive; and a step of removing the metal layer. Build method.