JPH09199552A - Measuring prober for circuit element with contact part of fine structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct the contact with a specimen with high accuracy and reliability and obtain low cost and high mass productivity by disposing a metal thin piece for constituting a contact land corresponding to the contact part of a circuit element on a prober board mounted and held on a base via a buffer member. SOLUTION: The measuring prober for a circuit element with the contact part of a fine structure comprises a base 21 and a prober board 1 mounted and held on the base 21 via a buffer member. A conductive metal thin piece having springness to constitute a contact land 3 corresponding to the array pattern of the contact part 6 of a circuit element 5 is disposed on the surface of the board 1 oppositely to the base 21, and the contact 7 which makes it possible to be brought into contact with the corresponding part 6 of the element 5 is given to the piece. A recess is formed at the position corresponding to the contact 7 of the piece on the surface of the board 1, and electric connecting means for electrically connecting the pieces to the external measuring unit is provided between base 21 and the board 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring prober for a circuit element having a contact portion having a fine structure, such as a semiconductor integrated circuit device or a liquid crystal display device.

[0002]

2. Description of the Related Art Conventionally, in an inspection device or an aging device for a semiconductor integrated circuit, probing of a semiconductor integrated circuit device wafer, a pellet containing a single or a plurality of devices (hereinafter referred to as a test object) and the like with high accuracy and high reliability. A prober for measurement is used for the purpose.

As a conventional measuring prober of this type,
It has conductivity only in the vertical direction by arranging needle-shaped hard metal such as tungsten carbide, or by penetrating a thin plastic sheet such as polyimide and forming a number of convex parts made of metal material called bumps on both sides A large number of thin metal wires are embedded in the vertical surface of a relatively thick sheet such as an anisotropic conductive sheet or a silicon rubber generally called anisotropic conductive rubber, and the elasticity of these thin wires is used for bending. was there.

[0004]

However, the needle-shaped hard metal has a very large area per unit as compared with the semiconductor integrated circuit element which is the object to be inspected, and a plurality of semiconductor circuits can be probed at one time. It was impossible to make something like that. In addition, the anisotropic conductive sheet has a poor separability related to the stress applied to each bump due to the rigidity of the plastic sheet as the base material, and a large pressure is applied even to the minute unevenness of the bump height. If it is not, the contact ratio will not be good, and since the anisotropic conductive rubber has a base made of a polymeric elastic body, it is difficult to obtain mechanical precision and has poor temperature characteristics.

An object of the present invention is to provide a measuring prober which can solve the above-mentioned problems of the conventional techniques.

[0006]

According to the present invention, in a measuring prober for a circuit element having a microstructured contact portion, the prober is attached and held to the base through a buffer member. A prober substrate, and the surface of the prober substrate opposite to the base is provided with a spring property that constitutes a contact land in an array pattern corresponding to the array pattern of the contact portion of the circuit element. A conductive thin metal piece is provided, the thin metal piece is provided with a contact capable of contacting a corresponding contact portion of the circuit element, and the thin metal piece is provided on the surface of the prober substrate. A recess is formed at a position corresponding to the contact point of, and between each of the base and the prober substrate, each of the metal flakes is electrically connected to an external measuring device. Electrical connection means provided Measuring prober characterized the door is provided.

In one embodiment of the present invention, each of the metal flakes is shaped like a cantilever with its tip terminating above the corresponding recess.

[0008] In another embodiment of the present invention, each of the metal flakes has a fixed end shape that is stretched across the recess.

In a further embodiment of the present invention, the recess is provided with an auxiliary cushioning member for cushioning the contact of the corresponding thin metal piece.

In another embodiment of the invention,
On the surface opposite to the surface of the probe board, a back surface land electrically connected to each of the metal flakes via a through hole is provided, and the base board is provided on the base board. Is attached to the main board, an electrical connector for connection to the external measuring device, relay lands arranged at positions corresponding to the respective backside lands of the probe board, and the relay lands. And a relay pattern for electrically connecting each of them to corresponding contact terminals of the electrical connector, and the buffer member corresponds to each of the relay lands of the parent board and the prober board. Consisting of individual buffer conductive members interposed between the back surface land and the electrical connection means,
The prober board includes the through hole and the back surface land, the individual buffer conductive members, the relay land of the parent board, the relay pattern, and the electrical connector.

In still another embodiment of the present invention, a surface of the probe substrate opposite to the surface is electrically connected to the metal thin piece through a through hole at a position corresponding to the metal thin piece. A conductive metal thin piece having a spring property that constitutes the backside land is disposed, and the surface of the opposite side of the prober substrate is recessed in a portion located below the metal thin piece forming the backside land. A base board is assembled to the base, and an electric connector for connection to the external measurement device and the back surface land of the probe board are configured on the base board. Relay lands arranged at positions corresponding to each of the metal flakes,
Relay patterns for electrically connecting each of the relay lands to the corresponding contact terminals of the electric connector are provided, and the contacts applied to the metal thin pieces forming the contact lands are the metal thin pieces. It is provided by a fixed conductive precision sphere, and a similar conductive precision sphere is provided between the metal thin piece forming the back surface land and the corresponding relay land of the parent substrate, and the buffer member is Provided by the springiness of the metal flakes forming the back surface land, the electrical connection means, the through-hole of the prober substrate and the metal foil forming the back surface land,
It is composed of a conductive precision sphere provided between the thin metal piece and the corresponding relay land of the parent board, the relay land of the parent board, the relay pattern and the electrical connector.

In still another embodiment of the present invention, the recess on the surface of the prober substrate and the recess on the opposite surface are common to penetrate from the surface to the opposite surface. Is provided by a through hole of
A coupling member is arranged between the thin metal pieces on both sides.

In yet another embodiment of the present invention, the connecting member is made of an elastic material.

In still another embodiment of the present invention, the coupling member is made of an elastic conductive material and also functions as the through hole.

In still another embodiment of the present invention, the surface of the probe substrate is provided with a relay pattern which is electrically connected to each of the metal thin pieces and extends to one end of the probe substrate. The base is assembled with a parent board, the parent board is provided with an electrical connector for connection to the external measuring device, and the electrical connection means is provided on the prober board. A flexible substrate is provided for electrically connecting the relay pattern at the one end to a corresponding contact terminal of the electrical connector.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in more detail with reference to the accompanying drawings.

First, before describing the preferred embodiments of the present invention, the ingenuity and ingenuity of the inventor until the present invention will be outlined below. The inventor of the present invention can contact an object with high accuracy and high reliability, eliminates the drawbacks of the conventional prober and is excellent in mass productivity, and further, IC wafers such as liquid crystal display devices having electrodes of the same fine structure. It was also possible to apply it to other inspection devices than the above, and various investigations were made with the intention of not providing a measurement prober that can be applied to a wide range of applications. As a result, the present inventor has found that the above-mentioned object can be successfully achieved by constructing the measurement probe with the following structure and technique.

That is, a metal thin plate or metal layer of a spring material such as beryllium copper or phosphor bronze is applied to the surface of a prober substrate formed by forming an insulating portion on the surface of an insulator such as ceramic or glass or metal. Set the circuit pattern by chemical etching, laser cutting, discharge cutting, etc., or by pasting a thin plate that has been molded in advance with a press machine, etc., and place it on the circuit pattern at the position that corresponds to the pad of the subject. The protrusions are formed by means such as plating, metal welding, electroforming, adhesion, or molding, or precision balls such as bearings are welded to form contacts.

Then, an opening such as a recess or a through hole is provided in the prober substrate corresponding to the back surface of the circuit pattern near the contact to increase the degree of freedom regarding the movement of the circuit pattern portion, and the tip of the circuit pattern on which the contact is installed. A moving part such as a diaphragm, a cantilever, or a cross-shaped or Y-shaped cross-linking type, a fixed tip type, etc. is formed in the vicinity of the part to make it possible to absorb the unevenness of the object or contacts or the mechanism. If necessary, an elastic body such as silicon rubber may be inserted into the space between the concave or open portion provided on the prober board and the circuit pattern formed by the thin metal plate to perform backup related to strength and elasticity. This allows precise electrical contact with the subject. In addition, half-moon parts are provided at both ends of the prober board,
A boss installed on a base made of a metal having a small thermal expansion coefficient and the half-moon portion are butted against each other to ensure the positional accuracy of the prober substrate.

Further, the prober substrate as described above is assumed to have a size in units of one or several test objects, but the prober board is related to the test object by considering the rigidity of the board and the processing method. In addition to being applicable to objects with a larger scale of integration, it also has the electrical connection and mechanical coupling function of external connection lands related to the circuit patterns on those prober boards, and allows the use of multiple prober boards. It is also possible to combine and expand a large-scale integrated body related to an object such as a semiconductor wafer so that probing can be performed at one time.

In this case, the connecting portion between the parent substrate and each prober substrate to which it belongs is made airtight and flexible so that the prober substrate can move freely, and the parent substrate is pressed by gas or fluid. Is applied or the atmospheric pressure is used by depressurizing the gap between the parent substrate and each prober substrate and the large-scale integrated body, and by the synergistic effect of the degree of freedom of the moving portion near the contact point and the individual prober substrate. It is possible to absorb the error between the contact point and the pad portion of the subject due to the surface error of the subject or the machining error of the mechanism.

According to the present invention as described above, a circuit pattern made of a thin metal plate or a metal layer of elastic metal is set on the surface of a prober substrate made of an insulator or a metal having an insulating portion formed on the surface, and the circuit pattern is further set. An opening such as a recess or a through hole is formed in the prober substrate on the back surface of the contact portion while providing a contact at a position corresponding to the pad of the subject on the top, and a metal thin plate or a metal foil on the recess or the opening is formed. By forming the moving part, it is possible to increase the degree of freedom of each contact, and to correct defects such as machining of the mechanical part, assembly error and difference in height between contacts, that is, contact and subject. It is effective in absorbing the contact error with the pad portion and averaging the contact pressure.

In addition, the connecting portion between the parent substrate and each prober substrate to be combined with the parent substrate is made airtight and flexible to allow the prober substrate to move freely, and the parent substrate is formed by gas or fluid. By applying pressure or depressurizing the gap between the parent substrate and each prober substrate and the large-scale integrated body and using atmospheric pressure, a synergistic effect on the degree of freedom by the moving portion near the contact point and individual prober substrate As a result, it is possible to absorb the error between the contact point and the pad portion of the subject due to the surface error of the subject, the machining of the mechanism, and the assembly error, and it is possible to make a precise and highly reliable contact with the subject.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure and operation of a measuring prober as various embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic plan view showing the structure of a measuring prober as one embodiment of the present invention, and FIG.
FIG. 4 is a sectional view taken along line AA of FIG. As shown in FIGS. 1 and 2, the measuring prober of this embodiment includes a prober substrate 1 and a base 21 for mounting and holding the prober substrate 1. The prober substrate 1 is mounted with contacts that come into contact with the pads (contact portions) of the subject 5 that is a circuit element having a contact portion having a fine structure. The base 21 relays contact signals to an external circuit. The parent board 2 for connection is assembled.

Contact lands 3 made of an elastic metal plate such as phosphor bronze or beryllium copper, and back lands 4 electrically connected by through holes 9 are provided on the front and back surfaces of the prober substrate 1, respectively. ing. Each contact land 3
A precision metal ball is welded to the tip portion 3a of the object 3 at a position corresponding to the pad 6 of the subject 5 shown in FIG.
The prober substrate 1 near the back surface of the contact 7 is provided with an opening 8 such as a through hole or a blind hole as shown in the drawing.

Therefore, each contact land 3 is formed in a cantilever shape, and the tip end portion 3a has a high degree of freedom regarding movement, so that the tip end portion 3a is deformed by the pressure applied to the prober substrate 1, and the subject 5 and the contact point are contacted. It is possible to cope with the mutual or unevenness of the mechanism, and the contact 7 rubs the surface of the pad 6 due to the moment generated at that time, so-called self-clean action occurs, and the oxide film can be destroyed. The contacts 7 may be of various types, but in addition to metal balls, those of ordinary conical shape or similar shape, or of various shapes such as molding a part of the tip in a convex shape. Can be

The electrical signals from the individual contacts 7 transmitted to the back surface land 4 through the through holes 9 pass through the relay pattern 10 formed on the mother board 2 to the connector 11 as shown in FIG. Relay land 1 connected to an external circuit
2, the buffer conductive means 13 such as a conductive rubber or a metal spring is interposed between the back surface land 4 and the relay land 12 at this time, so that the prober board 1 and the parent board 1 are connected. It is possible to absorb a relative error such as a deviation occurring between the two.

Between the back surface near the tip 3a and the open portion 8, auxiliary cushioning means such as silicon rubber or metal spring is provided to assist the elasticity and mechanical strength of the thin metal plate 3 related to the tip 3a. Although 14 is inserted, it may be omitted if the elasticity and flexibility of the thin metal plate 3 are appropriate. Further, as a means for increasing the stroke of the contact 7, a structure in which the vicinity of the tip portion 3a is bent and the tip portion 3a is lifted from the surface of the prober substrate 1 can be used. In that case, the auxiliary buffering means 14 is also applied. be able to.

As the prober substrate 1, an insulator such as ceramic or glass, or a metal substrate having an insulating portion formed on the surface thereof can be used. In particular, a pattern is formed on the glass surface by a photoresist which has recently become popular, and a chemical is used. The technique of forming a three-dimensional structure by etching is optimal.
The contact land 3 and the back surface land 4 are formed by forming a thin metal plate or metal layer of beryllium copper, phosphor bronze or the like, which is a spring material, on the prober substrate 1, and performing a method such as chemical etching, laser cutting or electric discharge machining, or a press machine beforehand. It is possible to form it by pasting a thin plate that has been molded by the above method.

Clamping bosses 15 for attaching and holding the prober substrate 1 and the parent substrate 2 are provided at both ends of the base 21. At both ends of the prober board 1, semi-circular apertures 1a for engaging and positioning the rods of the corresponding bosses 15 are formed. Positioning of the prober substrate 1 with respect to the base 21 and the parent substrate 2 is performed by sliding the semi-circular opening 1a and the corresponding rod portion of the boss 15 by precision fitting. Particles may be generated due to the dust. Therefore, as shown in FIG. 2, a dustproof material made of an elastic material such as silicon rubber is provided near the fitting portion between the boss 15 and the semicircular opening 1a formed in the prober substrate 1. It can also be prevented by applying 16 to form a soft coating film. Further, although the stopper 17 is provided at the bottom of the prober substrate 1 for the purpose of protecting the tip portion 3a and the contact 7, it may be provided between the semicircular portion 1a and the boss 15.

FIG. 3 illustrates several types of structural examples of the tip portion 3a of the contact land 3. In the embodiment shown in FIGS. 1 and 2, the tip portion 3a of the contact land 3 has a cantilever shape in order to obtain a necessary pressure, but the tip portion 3a of the contact land 3 is a recess. Open part 8
It can also be stretched across the top of. For example, the tip portion 3a of the contact land 3 has
It may have a diaphragm shape as shown in FIG.
It may be a cross-shaped type such as a cross type or a Y-shaped type as shown in FIG. 3B, or a fixed tip type as shown in FIG. 3C. In this way, the structure of these tip portions 3a can be selected according to the purpose.

As means for electrically connecting the backside land 4 and the relay pattern 10 relating to the prober substrate 1 and the parent substrate 2, the backside land 4 and the relay land 12 are used in the embodiment shown in FIGS. Also, the buffer conductive means 13 is used, but the invention is not limited to this, and various types can be used. For example, as shown in the partial views of FIGS. 4 and 5, it may be performed through the flexible substrate 18.
In this case, it is not necessary to process the back surface land 4, the relay land 12, the through hole 9 and the like, and the structure of the prober substrate 1 is simplified, but as shown by a black dot 10a in the figure, welding, soldering, etc. Therefore, it is necessary to electrically connect the prober board 1 and the parent board 2 with each other.
It is necessary to interpose a cushioning material 19 made of silicon rubber or the like.

Further, as another means relating to the electrical connection between the rear surface land 4 and the relay pattern 10, as shown in FIG. 6, the rear surface land 4 of the prober substrate 1 is provided with the contact land 3 provided on the surface. It is also possible to adopt a structure similar to that of the mechanism including the tip portion 3a and the contact point 7 so as to be in contact with the relay land 12 formed on the mother board 2.
In this case, as shown in FIG. 7, the open end 8 is formed as a through hole, and a coupling means 20 made of a shock absorbing material such as a spring or silicon rubber, or a rigid body such as a rod is inserted into the through hole so that the tip end is A so-called flying method, which is related to the elasticity assistance near the portions 3a and 4a and the stress between the tip portions 3a and 4a, can also be used. Further, when the coupling means 20 is a conductor, a through It is also possible to omit the hole 9.

Since these mechanisms are often exposed to high temperatures due to accelerated aging, errors due to the expansion coefficient of the material are likely to occur. In the present invention, as a means for ensuring the positional accuracy of the prober substrate 1, as shown in FIG. 1 and FIG.
An alloy having a small coefficient of thermal expansion, or an alloy close to metal such as silicon which is the material of the sample 5 (for example, RE of Nippon Foundry Co., Ltd.
X25 series, etc.) and ceramic base 21
The accuracy is maintained by engaging the boss 15 installed on the above with the half-moon portion 1a of the prober substrate 1. in this case,
Normally, the hole through which the boss 15 penetrates the parent substrate 2 needs to be set to be larger than the diameter of the boss 15 so as not to be affected by the thermal expansion of the parent substrate 2 due to a material such as epoxy resin. Is bonded to the base 21 to control thermal expansion.

For batch probing of a large-scale integrated circuit such as a semiconductor wafer, which has been recently requested, it is possible to increase the integration degree of the prober substrate 1 to deal with it. It is often inconvenient. In such a case, the semi-circular portion 1 of the prober substrate 1 is attached to a large number of bosses 15 that are installed by expanding the parent substrate 2.
By arranging “a” in abutment with each other, it is possible to perform efficient and precise alignment without needing a wasted space.

Further, the boss 15 which influences the positional accuracy of the prober board 1 is installed on the base 21 so as to penetrate the parent board 2 as shown in FIGS. The elastic body 22 such as a cylindrical coil spring shown in FIG.
May be added.

[0037]

According to the structure of the prober for measurement of the present invention, the prober can be brought into contact with the subject with high accuracy and high reliability, and can be mass-produced with good cost.

Application of the measuring prober according to the present invention I
With the C tester and aging device, it is possible to inspect the state of the IC pellets and the state of the wafer before cutting into pellets, so waste of intermediate steps is possible compared to the case of inspection after packaging. It can be prevented in advance, the production efficiency is significantly improved, and by considering the configuration of the device using the prober, it is possible to determine the distribution state of defective portions on the wafer.
There is a great merit that a defect in a retroactive process such as a defect of the IC pattern mask can be detected.

Furthermore, the measuring prober according to the present invention can be applied to a defect inspection device other than an IC wafer such as a liquid crystal display device having an electrode having a similar fine structure as an object, and is widely used. Applications can be expected.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing the structure of a measuring prober as one embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a diagram illustrating several types of structural examples of the tip end portions of contact lands provided on the prober substrate in the measuring prober of the present invention.

FIG. 4 is a partial plan view showing an example in which a flexible substrate is used for electrical connection between a prober substrate and a parent substrate in the measuring prober of the present invention.

FIG. 5 is a sectional view taken along line CC of FIG. 4;

FIG. 6 is a cross-sectional view corresponding to the cross-sectional view taken along the line BB of FIG. 1, showing a case where a contact land and a contact having substantially the same structure as the front surface are provided on the back surface of the prober substrate in the measuring prober of the present invention. is there.

FIG. 7 is a view similar to FIG. 6 showing a case where contact holes and contacts having substantially the same structure as the front surface are provided on the back surface of the prober substrate in the measuring prober of the present invention, and the open portion which is the recess is a through hole. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Prober board 2 Parent board 3 Contact land 3a Tip part 4 Back side land 4a Tip part 5 Specimen 6 Pad 7 Contact point 8 Open part 9 Through hole 10 Relay pattern 11 Connector 12 Relay land 13 Buffer conductive means 14 Auxiliary buffer means 15 Boss 16 Dustproof material 17 Stopper 18 Flexible substrate 19 Cushioning material 20 Coupling means 21 Base 22 Elastic body

Claims (10)

[Claims] 1. A prober for measurement for a circuit element having a microstructured contact portion, comprising a base and a prober substrate attached and held to the base via a buffer member, On the surface of the prober substrate opposite to the base, spring-like conductive metal flakes forming contact lands are arranged in an arrangement pattern corresponding to the arrangement pattern of the contact portions of the circuit element. The metal flakes are provided with contacts capable of contacting the corresponding contact portions of the circuit element, and the surface of the prober substrate has a recess at a position corresponding to the contacts of the metal flakes. An electrical connection means is provided between the base and the prober substrate for electrically connecting each of the metal flakes to an external measuring device. A characteristic prober for measurement. 2. The prober for measurement according to claim 1, wherein each of the metal thin pieces is formed in a cantilever shape such that a tip end thereof is located above the corresponding recess. 3. The prober for measurement according to claim 1, wherein each of the thin metal pieces has a fixed shape in which both ends are stretched across the recess. 4. The prober for measurement according to claim 1, wherein an auxiliary cushioning member that cushions the contact of the corresponding thin metal piece is provided in the recess. 5. A back surface land electrically connected to each of the metal flakes through a through hole is provided on a surface of the probe substrate opposite to the surface, and the base is provided. A main board is attached to the main board, and the main board has an electrical connector for connection to the external measuring device and a relay land arranged at a position corresponding to each of the back surface lands of the probe board. And a relay pattern for electrically connecting each of the relay lands to a corresponding contact terminal of the electrical connector, the buffer member, each of the relay lands of the parent board, The prober board includes individual buffer conductive members interposed between the back surface land and the corresponding back surface land, and the electrical connection means includes the through hole and the back surface land of the prober board. , The individual buffer conductive members,
3. The relay land of the parent board, the relay pattern, and the electrical connector.
Alternatively, the measuring prober according to 3 or 4. 6. A spring property which forms a back surface land electrically connected to the metal thin piece via a through hole at a position corresponding to the metal thin piece on a surface opposite to the surface of the probe substrate. A conductive thin metal piece having a groove is formed, and a recess is formed in a portion of the opposite surface of the prober substrate located below the thin metal piece forming the back surface land. A mother board is assembled to the table, and the mother board has a position corresponding to each of an electrical connector for connecting to the external measuring device and a metal thin piece forming the back surface land of the probe board. And relay patterns for electrically connecting each of the relay lands to the corresponding contact terminals of the electric connector are provided, and the relay lands are provided on the metal thin pieces forming the contact lands. The contact point provided is provided by a conductive precision sphere fixed to a metal thin piece, and a similar conductive precision sphere is provided between the metal thin piece forming the backside land and the corresponding relay land of the parent board. The cushioning member is provided by the spring property of the metal thin piece forming the back surface land, and the electrical connecting means is a metal thin piece forming the through hole of the prober substrate and the back surface land, and the metal. 2. A conductive precision sphere provided between a thin piece and the corresponding relay land of the parent board, the relay land of the parent board, the relay pattern and the electrical connector. Prober for measuring. 7. The recess of the surface of the prober substrate and the recess of the opposite surface are provided by a common through hole penetrating from the surface to the opposite surface, 7. The prober for measurement according to claim 6, wherein a coupling member interposed between the thin metal pieces on both sides is arranged in the through hole. 8. The measuring prober according to claim 7, wherein the coupling member is made of an elastic material. 9. The prober for measurement according to claim 7, wherein the coupling member is formed of a conductive material having elasticity and also functions as the through hole. 10. A relay pattern, which is electrically connected to each of the metal flakes and extends to one end of the probe substrate, is provided on the surface of the probe substrate, and the base is provided with a relay pattern. A substrate is assembled, the parent substrate is provided with an electrical connector for connection to the external measurement device, and the electrical connection means is the relay pattern and the relay pattern at the one end of the prober substrate. 4. A flexible substrate for making an electrical connection between corresponding contact terminals of an electrical connector.
Or the prober for measurement according to 4.