KR101358788B1 - High density probe card and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a probe card for determining whether a semiconductor integrated circuit is defective. The probe card of the present invention includes a probe unit unit, an interposer unit, and a main board unit, and the probe unit unit contacts the electrode pad of the integrated circuit. And a plurality of probes and a wiring board coupled to the plurality of probes, wherein the plurality of probes are fixed to an upper surface of the wiring board so that both of the probes are electrically connected to each other. It is energized up and down through an electrode hole, the main board portion includes a top plate, a bottom plate, a transmission line (Trace) and via holes (Via Hole), a plurality of circuit patterns for the test is formed, the interposer portion conductive elastomer It has a structure, and positioned between the wiring board and the top plate of the main board portion to be electrically connected, the area of the top plate is Is formed smaller than the area of the plate is characterized in that the thickness of the central portion being connected to the probe unit portion than the thickness of the main plate portion connector mounting portion connected to the tester thick.
According to the probe card of the present invention, by manufacturing a multi-stage PCB to replace the space transformer PCB of the conventional probe card to improve the performance to maximize the amount of testable semiconductor at the same time, thereby reducing the cost of semiconductor testing.

Description

High Density Probe Card And Method For Manufacturing The Same

The present invention relates to a probe card for determining whether a semiconductor integrated circuit is defective. To determine whether the defect is a defect, the probe card transmits an electrical signal generated by a tester as an interface board for conduction test to an integrated circuit.

Generally, the integrated circuit manufactured by the semiconductor process is very complicated, the number of electrodes is large, and the types are various. When the manufacture of such integrated circuits is completed, the electrical characteristics and defects of the integrated circuits are inspected using the inspection apparatus. A probe card is used to check the electrical characteristics of such integrated circuits. Such a probe card connects the circuit tester and the integrated circuit to inspect the electrical characteristics of the circuit.

The probe card for wafer testing includes a tester for reading test data and generating test signals in Electrical Die Sorting (EDS) for checking the electrical characteristics of an integrated circuit chip in a wafer state and loading the wafer It is the interface part that connects the probe station to enable the test to be performed. The probe card is mounted on the probe station and is connected to a tester, and each probe contacts the electrode pads and transmits a signal of the tester to the integrated circuit chip of the wafer.

Integrated circuit chips formed on a semiconductor wafer through a wafer fabrication process are classified into good and defective products by Electrical Die Sorting (EDS) conducted in a wafer state. The electric characteristic inspection includes a tester for generating an inspection signal and determining the inspection result, a probe station for loading and unloading semiconductor wafers, a semiconductor wafer and a tester A test apparatus composed of a probe card for electrical connection is mainly used.

In the above-described inspection apparatus, a probe card is generally constructed in such a manner that a probe block of a ceramic material is fixed on a main board, and a probe is fixed to the probe block by an epoxy resin . A conventional probe card uses a space transformer in which a main circuit board and a probe are electrically connected and fixed and an interposer to electrically connect the space transformer and the probe. The space transformer electrically connects the probe and the main circuit board, and appropriately converts the pitch difference between the probe and the main circuit board. Particularly, as the degree of directivity of a semiconductor device is improved, a probe card for testing it is required to be capable of high-density and high-speed testing. As the size of the integrated circuit chips becomes smaller, the density of the test channel for testing increases, and as a result, the density of the main substrate increases and the distance between the via-holes becomes smaller. As the distance between the via-holes decreases, the number of circuit patterns passing between the via-holes decreases, thereby increasing the number of layers of the main substrate. However, since the size and thickness of the main substrate are determined according to the specifications of the tester, there is a problem that the main substrate is restricted.

Registration Utility Model No. 20-0450813 (Probe Card Using Space Transformer Substrate)

As semiconductor integrated circuits become smaller, faster, and have higher performance, probe cards for testing them are required to be capable of high density and high speed testing. In particular, as the degree of directivity of a semiconductor device is improved, the probe density of the probe card for testing the semiconductor device is greatly increased. In addition, the conventional tester resources are limited, and the area in which the probe card can be tested at the same time in order to reduce the test cost is continuously increasing.

Accordingly, the number of mounting of electronic components such as relays and ASICs required to expand the inspection area in the printed circuit board of the probe card is also greatly increased. As a result, the number of wirings in the printed circuit board is greatly increased, thereby increasing the number of layers of the board. Done.

However, due to the limitation of the interface structure between the prober and the tester, it is difficult to use the thickness of the main PCB over a specific thickness. Due to this limitation, the main PCB has a problem that it becomes difficult to accommodate the rapidly increasing wiring.

To solve this problem, most probe cards use a space transformer between a printed circuit board and a contact probe to house a part of the printed circuit board wiring using a multilayer ceramic substrate or a separate space transformer PCB.

However, the price of the multilayer ceramic substrate and the space transformer PCB used here is over 50% of the cost of the probe card, and the manufacturing time is also long, so the economy is largely lacking.

The present invention increases the number of layers or increases the number of layers by applying a printed circuit board for a probe card in a multistage form in which the substrate thickness of the inner portion without mechanical constraints of the interface between the prober and the tester is extended. The fabrication of a high density probe card is facilitated by applying a BVH / IVH type multi-stage substrate which is manufactured by bonding the substrate separately. That is, in order to improve the performance by replacing the space transformer PCB in the conventional probe card by manufacturing a multi-stage PCB.

In order to achieve the above object, the probe card of the present invention includes a probe unit unit, an interposer unit and a main board unit, and the probe unit unit includes a plurality of probes and the plurality of probes in contact with electrode pads of an integrated circuit. And a plurality of probes fixed to an upper surface of the wiring board so that both of the probes are electrically connected to each other. The wiring board has a pattern circuit on the upper and lower surfaces and is energized up and down through an electrode hole. The main board portion includes a top plate, a bottom plate, a trace line, and a via hole, and a plurality of circuit patterns are formed for a test, and the interposer portion has a conductive elastic structure and is electrically connected to the wire. Located between the substrate and the upper plate of the main board portion, the area of the upper plate is formed smaller than the area of the lower plate and the tester The thickness of the center portion connected to the probe unit portion is thicker than the thickness of the connector mounting portion of the main board portion to be connected.

In addition, the probe card may include a main printed circuit board formed of a multilayer printed circuit board, a via hole gap of the upper substrate is smaller than a via hole gap of the housing substrate, and the main board unit may be formed of the multi-layer printed circuit board. A reinforcing plate supporting the lower plate by tightly coupling with the lower plate at an opposite side of the upper plate; And a connector, wherein the main board part is electrically connected to the tester by a test channel formed in the connector, and the test channel is connected to the inside of the main board part through the transmission line and the via hole.

The probe card may further include a fixing frame connecting the probe unit part to the reinforcement plate and fixing the fastening member installed through the lower plate or the probe unit part to the main board part.

The configuration of the probe card is largely divided into a main board part electrically connected to the tester, a probe unit part contacting the integrated circuit, and an interposer part electrically connecting the main board part and the probe unit part.

Each test channel is electrically connected to each other through a connector such as a tester and a connector. Each channel of the tester is connected to the inside of the main board through a transmission line and a via hole inside the main board.

The interposer part performs a function of electrically connecting each test channel connected to the inside of the main board part with the probe unit part, and is made of a contact type so that the probe unit part is easily detachable. Therefore, the conductive elastomer is often formed.

The probe unit includes a probe that is in direct contact with an electrode pad of an integrated circuit (IC), and a wiring board to which the probe is fixed and electrically connected.

The wiring board has pattern circuits on the top and bottom and is energized through the electrode holes up and down. The probe is fixed to the upper pattern, and the signal of the tester is connected to the probe to the lower pattern.

In the pro unit unit, the wiring board to which the probe is fixed is mainly a ceramic substrate.

The probe card having the above structure is mounted on a prober (wafer transfer device) for testing a wafer. As the test header of the tester is docked, the connector located on the outside of the printed circuit board of the probe card and the connector of the test header are electrically connected. Connected.

At this time, the connector of the probe card and the connector of the tester header to mechanically limit the distance between the male and female connectors during the manufacturing of the equipment for accurate locking (Locking).

Therefore, the printed circuit board for the probe card must maintain a specific size and thickness according to the interface specification of the prober and tester head. For this reason, the user of the probe card is presenting the manufacturing specifications such as the size and thickness of the printed circuit board for the probe card to the probe card manufacturer.

The printed circuit board for the probe card is limited to be manufactured according to the type of tester, so it is impossible to design the circuit board more than a specific number of stacks.

Examining the environment of using a conventional probe card, the outer part of the printed circuit board where the connector of the tester head and the connector of the probe card are combined cannot be physically changed in thickness unless the equipment is remodeled. The thickness can be changed within a limited range. Accordingly, the number of layers can be increased by maintaining the thickness of the outer portion of the printed circuit board as it is, and increasing the thickness of the inner portion where the degree of adhesion of the wiring circuit is high.

That is, by using a multi-stage circuit board having dual thicknesses of the outside and the inside of the printed circuit board for the probe card, it is possible to manufacture a semiconductor test probe card for high para and high pin count by manufacturing a printed circuit board capable of ultra-high multilayer implementation. In addition, when the multi-stage printed circuit board is implemented, the substrate is divided into upper and lower parts, and in the case of the upper substrate, the via density can be increased by implementing the via pitch smaller than the lower substrate.

According to the present invention, it is possible to maximize the amount of semiconductors that can be tested at the same time by overcoming the design constraints caused by the multiplexing of the printed circuit board for the probe card, thereby reducing the semiconductor cost.

In addition, it improves the contact problems and electrical characteristics between the conventional interposer and the printed circuit.

1 is an exploded perspective view of a schematic portion of a conventional probe card.
2 is an exploded bottom perspective view of a schematic portion of a conventional probe card.
3 is a schematic cross-sectional view taken along line DE of a conventional probe card.
4 is a schematic cross-sectional view of another conventional probe card.
5 is a cross-sectional view of the probe card according to the first embodiment of the present invention.
6 is a sectional view of a probe card according to a first embodiment of the present invention.

The above and other objects, features, and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings, which are not intended to limit the scope of the present invention. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to denote the same or similar elements.

The conventional probe card 100 includes a probe unit unit 10, an interposer unit 20, and a main circuit board unit 30.

The probe unit unit 10 may be configured of the probe 11 and the wiring board 13.

The probe 11 has a cantilever shape, such as an enlarged area of portion A shown in FIG. 1, with one end portion 110 of the probe 11 positioned on the same plane, and formed on the wafer. It is arranged in the same position and spacing as the pads for connection terminals. The other end 111 of the probe 11 is electrically connected by being attached in various forms such as solder bonding or intermetallic bonding by a circuit pattern formed on the wiring board 13. In the present embodiment, the probe 11 is a cantilever shape, but is not limited thereto. The probe 11 may have various shapes such as a vertical shape.

The wiring board 13 may be electrically connected to the opposite surface from the surface attached to the probes 11 to be electrically connected to the first interposer 21 together with the elastic contact.

The probe card 300 according to the first embodiment of the present invention includes a probe unit 310, an interposer 320, and a main board 330.

Since the probe unit unit 310 of the present invention is similar to the conventional pro unit unit 10, a detailed description thereof will be omitted.

The main board unit 330 includes an upper plate 332, a lower plate 331, and a reinforcing plate 335.

The upper plate 332 and the lower plate 331 may be manufactured integrally, or may be manufactured separately for convenience of manufacturing. The thickness of the center portion connected to the pro unit unit 310 is greater than the thickness of the connector 336 mounting portion of the main board 330 connected to the tester because the area of the upper plate 332 is smaller than that of the lower plate 331. thick.

The upper plate 332 and the lower plate 331 are formed with a plurality of circuit patterns for testing the integrated circuit chip on the wafer, and include a transmission line and a via hole.

An inspection device (not illustrated) in which one surface of the upper plate 332 is electrically connected to the interposer 320 and electrically connected thereto, and one surface of the lower plate that is not in contact with the interposer 320 is generated to transmit a test signal to a probe. May be electrically connected). The upper plate 332 and the lower plate 331 may be formed of FR-4, a BT resin, or the like, which is a heat resistant epoxy resin.

The upper plate 332 and the lower plate 331 may be manufactured separately, but in order to solve the electrical characteristics and contact problems, it is preferable to manufacture integrally. That is, the upper plate and the lower plate can be formed by the PCB manufacturing process, and it is also possible to manufacture the main board unit 330 by lowering and removing the outer portion of the thickly manufactured PCB to the tester limit height. That is, the upper plate 332 and the lower plate 331 may be distinguished through a process of removing the outer portion from the integrally manufactured PCB without separately manufacturing the upper plate 332 and the lower plate 331 of the main board unit 330. You can do that.

In the past, due to technical limitations on the PCB fabrication, it was difficult to form ultra-high-layered and multi-stage PCBs. However, as technology advances, PCB fabrication technology has been improved, making multilayer PCB easier to implement. In the present invention, it is possible to manufacture a multi-stage PCB of a desired shape by using the (IVH) method, such as forming a PCB after the PCB fabrication or by combining two PCBs.

The reinforcing plate 335 is installed on the lower surface of the lower plate 331, which is the opposite side of the upper plate 332, and serves to prevent physical deformation of the main board unit 330. The material of the reinforcing plate 335 is preferably made of a material having the same coefficient of thermal expansion as the upper plate 332 and the lower plate 331. For example, it may be composed of a metal such as carbon steel or stainless steel. The reinforcement plate 335 has a circular plate-shaped square shape at the center, but in addition, it may have various other shapes such as hexagonal and octagonal.

The fastening member 340 connects the probe unit 310 and the reinforcement plate 335 and is installed to penetrate the lower plate 331.

The interposer 320 serves to electrically connect the probe unit 310 and the main board 330 to be in elastic contact with each other. The interposer 320 forms a thin plate shape and serves as a conductive elastic body. The interposer 320 includes a plurality of conductive elastic pins and the plurality of conductive elastic pins are arranged in a plane vertically in a straight line according to the position of the terminal to be contacted to serve to electrically interconnect the middle. . The elastic pin may be a pogo pin. The interposer 320 and the probe unit 310 may have a greater elasticity than the wafer contact load. The upper plate 332 and the lower plate 331 may be formed of a multilayer printed circuit board (MLB) to perform a function of a space transformer.

The space transformer may extend the pitch of the probe unit 310.

The multilayer printed circuit board performs the function of the space transformer. That is, the upper plate 332 and the lower plate 331 may be formed of a multilayer printed circuit board in order to convert a pitch difference between the probe unit 310 and the main board 330. The multilayer printed circuit board should be resistant to thermal deformation and lamination, and the material of the multilayer printed circuit board may be FR-4, BT resin, or the like, which is a heat resistant epoxy resin.

According to the embodiment of the present invention, by forming the space transformer as a multilayer printed circuit board, the pitch interval of the upper plate 332 can be formed larger than the pitch interval of the interposer 320, the lower plate 331 The pitch interval may be greater than the pitch interval of the upper plate 332.

A plurality of via holes and traces may be formed in the multilayer printed circuit board forming the upper plate and the lower plate. Via holes form vertical electrical passages and traces form horizontal electrical passages.

 The via hole may be divided into a normal via hole, a blind via hole, and a buried via hole. The normal via hole is a hole connected from the uppermost layer to the lowest layer, and both ends are penetrated. The blind via hole is a hole connected from the uppermost layer to the intermediate layer or from the bottom layer to the intermediate layer, and the buried via hole is a hole connected from the intermediate layer to another intermediate layer. The via hole is plated with a conductive material to conduct electricity to the inner circumferential surface of the hole.

Meanwhile, in this embodiment, the via hole may be any one of the normal via hole, the blind via hole, and the via via hole.

The trace is an internal transmission line which is covered with a conductive material and composed of conductive wires for electrically connecting the via holes to each other. Thus, the internal connection of the multilayer printed circuit board can be electrically connected by via holes and traces. The upper plate 332 and the lower plate 331 may be electrically connected to each other by an internal connection structure of the via holes and the traces.

The space transformer may be formed of an embedded printed circuit board (not shown). The embedded printed circuit board refers to a substrate in which passive components such as a capacitor, a resistor, an inductor, and the like are integrated in the printed circuit board. Preferably, the embedded printed circuit board may be formed in multiple layers.

When the space transformer is formed of an embedded printed circuit board (not shown), since a passive element such as a capacitor, a resistor, an inductor, etc. may be built in, the space may be additionally secured to accommodate many circuits. The interposer 320 may be integrally attached to the embedded printed circuit board. In addition, when the space transformer is formed of an embedded printed circuit board as described above, the number of probes of the probe unit 310 is increased as a result, and many semiconductor chips can be inspected, thereby making it possible to manufacture a high speed and high density card.

As such, the test signals of the main board 310 pass through the interposer 320 through the via holes and the horizontal path traces. The test signals passing through the interposer 320 are transmitted to a plurality of probes through a wiring board to check a good / bad state of a chip on a wafer to be inspected.

The probe card according to the second embodiment of the present invention includes a fixing frame 433 instead of the fastening member.

The fixing frame 433 is fixed to the lower plate 431 and fixes the probe unit 410 and the interposer 420 so as not to be shaken. The plurality of probes 411 of the probe unit 410 should not be shaken or moved because they must be correctly connected to the chip to be inspected of the wafer. Likewise, since the interposer 420 must transmit the test signal of the main board 430 to the probe unit 410 correctly, the interposer 420 must be connected to a precisely defined connection and must not be shaken or moved. Therefore, in order to fix them all to the lower plate 431, the fixed frame 433 is applied.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, But the present invention is not limited thereto.

310 probe unit
320 interposer
330 Main Board
331 lower plate
332 tops
335 gusset
336 connectors
340 fastening member
433 fixed frame

Claims (8)

A probe card comprising a probe unit portion, an interposer portion, and a main board portion,
The probe unit unit includes a plurality of probes in contact with an electrode pad of an integrated circuit and a wiring board coupled to the plurality of probes, and the plurality of probes are fixed to an upper surface of the wiring board so that both are electrically connected. The wiring board has pattern circuits at the top and bottom and is energized up and down through the electrode holes.
The main board portion includes an upper plate, a lower plate, a transmission line and a via hole, and a plurality of circuit patterns are formed for the test.
The interposer portion has a conductive elastic structure, and is located between the wiring board and the upper plate so as to be electrically connected.
And an area of the upper plate surface smaller than an area of the lower plate surface, and having a thickness greater than that of the main board portion connected to the tester to a thickness of the central portion connected to the probe unit. The method of claim 1,
And the main board portion is formed of a multilayer printed circuit board. 3. The method of claim 2,
Probe card, characterized in that the via hole spacing (Via Pitch) of the upper plate is smaller than the via hole spacing (Via Pitch) of the lower plate. The method of claim 1,
The main board portion,
A reinforcing plate supporting the lower plate by tightly coupling with the lower plate at an opposite side of the upper plate; And
Further includes a connector,
And the main board part is electrically connected to the tester by a test channel formed in the connector, and the test channel and the lower plate are electrically connected through the transmission line and the via hole. The method of claim 4, wherein the probe card,
And a fastening member connecting the probe unit to the reinforcement plate and installed through the lower plate. The method according to any one of claims 1 to 4, wherein the probe card,
And a fixing frame to fix the probe unit to the main board. 5. The method according to any one of claims 1 to 4,
The main board portion is a probe card, characterized in that manufactured using the IVH (Inner Via Hole) or BVH (Buried Via Hole) method for manufacturing and bonding the upper plate and the lower plate separately of the PCB manufacturing method. 5. The method according to any one of claims 1 to 4,
The main board portion, the probe card, characterized in that manufactured by removing the outer portion of the upper plate of the outer portion of the PCB manufactured integrally.

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