JP3098791B2 - Probe board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe board and, more particularly, to a technique effective for use in obtaining electrical connection with a semiconductor chip completed on a semiconductor wafer.

[0002]

2. Description of the Related Art Instead of a probe board using a thin probe needle made of tungsten or the like as in the prior art, a wiring made of a fine pattern is formed on a flexible film base by using photographic technology, and the wiring is formed. Probe cards for use as probes have been developed. In this probe card, signal lines that act as probes can be formed by using photographic technology. Therefore, a semiconductor integrated circuit having a high-density electrode that cannot be measured using a conventional probe needle made of thin filaments cannot be measured. The circuit can be measured. For such a probe card, for example, the magazine "SEMICONDUCTOR INTE
RNATIONAL) ", August 1988, pages 98 to 101.

[0003]

In the above-mentioned probe card, a wiring layer is formed on a conical integral film base having a bottom surface corresponding to a semiconductor chip. Therefore, the tip of the wiring contacting the electrode of the semiconductor chip is in a completely fixed state. In this configuration, the tip of the wiring is simply pressed against the surface of the semiconductor chip, so that an oxide film cannot be formed on the electrode made of an aluminum layer or the like of the semiconductor chip, or the attached dust cannot be broken through. The problem is that a good electrical contact cannot be obtained. On the other hand, when a conventional thin probe needle made of tungsten or the like is used, since the probe needles correspond to the electrodes of the semiconductor chip one by one, the assembly is relatively complicated. However, since a needle mainly containing is used, there is a problem in high frequency characteristics as a transmission path. SUMMARY OF THE INVENTION An object of the present invention is to provide a probe board capable of simplifying assembly and obtaining good signal transmission characteristics. The above and other objects and novel features of the present invention are as follows.
It will be apparent from the description of this specification and the accompanying drawings.

[0004]

The following is a brief description of an outline of a typical invention among the inventions disclosed in the present application. That is, wiring means corresponding to the electrode provided on one side of the semiconductor device is formed on the flexible wiring board, and the connection end side is electrically connected thereto,
A probe whose tip is fitted to the electrode to be measured is provided, and a guide portion for inserting the probe is provided along with the flexible wiring board so that the probe is sandwiched between the probe and the laminated structure. A probe assembly is configured by attaching an elastic body for imparting the property to the lower surface of the probe mounting body and pressing the lower surface of the probe mounting body from the lower surface side, and forming the probe assembly on one or a plurality of electrodes of the semiconductor device. One or more correspondingly provided probe assemblies are attached to the wiring board.

[0005]

According to the above-described means, the probe inserted into the guide portion of the film can be inserted into the laminated structure of the flexible wiring board and the film and attached to the probe assembly. Accordingly, the electrodes of the semiconductor device are brought into contact with each other, and since most of the signal transmission paths can use wiring means formed on the flexible wiring board, good signal transmission characteristics can be obtained.

[0006]

FIG. 1 is a sectional view of an embodiment of a probe board according to the present invention, and FIG. 2 is an enlarged sectional view of a main part thereof. The probe board is mounted on a semiconductor wafer prober in a horizontal direction as shown in FIG. 2, but is drawn in a vertical direction in FIG. The tab (TAB) substrate uses a manufacturing technology such as a flexible flat cable, and is formed of a plurality of electrodes (bonding pads, etc.) formed on one side of a semiconductor integrated circuit to be measured using a photographic technology on a flexible film base. )
In this case, the leading end is roughly aligned and is formed of a wiring layer. A film as a needle hole guide is formed corresponding to the tip of the tab substrate. A hole as a needle hole guide (probe guide) having an arrangement corresponding to the electrodes is formed at the leading end of the film. The needle hole is not particularly limited, but is accurately formed in accordance with the arrangement of the electrodes by using a stamping process or a laser beam.

The tip of a probe needle made of a conductive metal having a relatively high hardness mainly containing tungsten or the like is inserted into the needle hole. This probe needle can be basically the same as the probe needle used for the conventional fixed probe board, but the length thereof is significantly shorter than the conventional one. That is, the tip of the probe needle of this embodiment is bent by about 90 °, and cut from the bent portion by a length of several mm. Since the needle holes of the film are formed exactly in accordance with the electrode arrangement of the semiconductor chip, the bent tip portions of the probe needles are inserted into the holes, so that the tip of each needle is to be measured. It can be correctly aligned with the electrode.

[0008] By overlapping the tab substrate from above the probe needles arranged on the film as described above, the connection end of the probe needle and the wiring formed on the tab substrate can be brought into electrical contact. . In order to more reliably fix this contact, soldering may be performed using, for example, solder, or connection may be performed using a connection medium such as an anisotropic conductive film. The above soldering is relatively simple, for example, by forming a solder layer at the connection portion of the wiring means formed on the tab substrate and the connection end of the probe needle, and performing heat treatment in the state of being overlapped as described above. Can be done. At this time, a spacer slightly thinner than the diameter (height) of the probe needle may be provided on the surface of the film base other than the portion where the probe needles are arranged.
In this embodiment, silicon rubber as described later is used as the spacer. As described above, the probe needle is fixed by being sandwiched from above and below by the tab substrate and the film. As described above, the tab substrate forming the signal transmission path, the probe needle for making contact with the electrode of the semiconductor chip, and the film for aligning the tip of the probe are integrated into a laminated structure.

In the case where electrodes are provided corresponding to four sides of a semiconductor chip (semiconductor device) having a square shape, four probes having a laminated structure corresponding to the electrodes provided on the four sides are provided. Is formed.

The probe having the above-mentioned laminated structure is mounted on the lower surface of the probe mounting body via silicon rubber as an elastic body in order to impart a spring property to the tip portion.
The lower surface of the probe mounting body is tapered or cone-shaped so as to have an angle with respect to the surface of the semiconductor chip. A silicon rubber is provided at the tip of the probe having the above-mentioned laminated structure. The mounting of the probe having the above-mentioned laminated structure to the probe mounting body is performed by a clamping plate. The clamping plate is fixed so as to be supported by the lower surface of the film and pressed against the support surface of the probe mounting body. In other words, the clamping plate has a concave cross section in a direction perpendicular to the axis of the probe needle, supports the probe of the laminated structure on its bottom surface, and is screwed on both sides so as to sandwich the probe mounting body. ing. This makes it possible to maintain a laminated structure composed of a film, a flexible wiring board, and probe needles having the above-described flexibility with appropriate strength against repeated pressure bonding to a semiconductor chip or a semiconductor device. A probe assembly corresponding to a plurality of electrodes provided on one side of a semiconductor chip or a semiconductor device is constituted by a probe having the above-mentioned laminated structure and a probe attaching body attached to the probe via an elastic body such as silicon rubber. Is done.

Although not particularly limited, wires formed on the tab substrate are omitted in FIG. 1 in order to perform good signal transmission, but shield wires are provided between wires as signal transmission lines. Can be If the space for forming the shield line becomes insufficient due to the denseness of the wiring layers at the leading end, the shield line is provided except for that part. A power supply line for applying a power supply voltage or a ground potential to the semiconductor chip is guided to the vicinity of the connection end of the probe needle by a thick wiring on the opposite side of the tab substrate, and is connected to a wiring layer connected to the probe needle through a through hole therefrom. May be used. By doing so, the power supply impedance can be reduced. Alternatively, the tab substrate may extend toward the board while spreading in a fan shape from the connection portion with the probe. With this configuration, the space between the wirings can be widened, so that a mounting space for forming the above-described shielded wire can be secured.

The probe assembly is mounted on a ring plate provided along an opening provided at the center of a board made of a printed wiring board. The attachment to the ring plate is performed by an attachment screw, and the tip of the probe needle is finely adjusted by a push screw. The set screw is used to correctly set the relative positions of a plurality of probe assemblies provided corresponding to two or more sides of one semiconductor chip. That is, the tip of the probe needle corresponding to the electrode on one side is
Correct alignment is achieved by the needle holes in the film. However, unless the relative positions of the individual needle tips corresponding to the plurality of sides are performed, electrical contact cannot be made to all the electrodes of one semiconductor chip at the same time.

The fine adjustment of the needle point in the horizontal direction is performed by lightly loosening the mounting screw and then adjusting the height of the needle tip by the height of a total of four push screws as described later with reference to FIG. I do. An elliptical hole is provided in the X-axis and Y-axis directions for the mounting screw, and a knob with an eccentric cam is provided in this hole.
By operating these knobs, the Y axis or X
Tighten the mounting screws while making fine adjustments along the axis. By performing the above operation on the four probe assemblies, it is possible to obtain the probe needles respectively aligned with the electrodes of one semiconductor chip.

FIG. 3 is a bottom view of the probe board according to the present invention, and FIG. 4 is an enlarged view of a central portion. In the figure, the left and right portions of the circular probe board are omitted because they are similar or similar to the upper and lower portions shown. The needle hole is formed vertically long along the extension direction of the probe needle, and when the needle tip comes into contact with the semiconductor chip, the tip portion corresponds to the bite amount of the needle,
It is made so as not to hinder sliding movement on the electrode surface by a very small distance toward the front. The movement of the tip of the needle causes the tip and the electrode surface of the IC to be measured to be rubbed and moved while having a predetermined contact pressure. Waste can be removed. By such a contact operation, a good electrical contact can be stably obtained.

The needle hole as described above is provided with play with respect to the needle tip, so when setting the needle in the needle hole,
What is necessary is just to fix the position of the front-end | tip part bent before the needle hole. In the figure, mounting screws provided on the left and right sides of the probe mounting body are for mounting the concave clamping plate. In FIG.
The other end of the wiring pattern provided on the tab substrate is connected to the connection end of the wiring pattern provided on the board by solder or the like. The other end of the wiring means provided on the board terminates in a circular through hole, where a connecting pin is provided. If the tab substrate is made to spread in a fan shape when extending to the board side, it is possible to secure the above-described shielded wires and to increase the pitch of the connection ends provided on the board. The connector pins provided on the board are the same as those of a conventional probe board in which tungsten needles are fixed radially. That is, the probe board of this embodiment is of a so-called plug-in type which is attached to the mother board via the connector pins.

FIG. 5 is a plan view showing another embodiment of the needle holes provided in the film. The needle holes do not need to be completely independent of each other in the shape of a long circle, and may have any configuration as long as the needle contacts the electrode of the semiconductor chip and covers the minute movement amount of the tip portion. Therefore,
As shown in the figure, the needle hole may be configured such that a comb-shaped groove is connected at the needle tip, or a comb-shaped groove is provided at the end corresponding to the needle point of the film base, and the groove is substantially formed. It may be configured as a simple needle hole.

FIG. 6 is a bottom view of the probe board according to the present invention. In the figure, the left and right portions of the circular probe board are omitted because they are similar or similar to the upper and lower portions shown. Four probe assemblies as described above for making electrical connections to the electrodes corresponding to the four sides of the semiconductor chip are mounted on the ring plate. This mounting is performed by mounting screws. An elliptical hole is provided in one direction (X) in the arrangement direction and a direction perpendicular thereto (Y direction) with the mounting screw interposed therebetween, and fine adjustment in the X and Y directions is performed by the eccentric cam or the like as described above. Will be In addition, four push screws are provided around the mounting screw, and are used for fine adjustment of the needle tip in the horizontal direction.

For a semiconductor chip in which electrodes are provided only on opposite short sides of a rectangular semiconductor chip, such as a semiconductor chip of a dynamic RAM having a storage capacity of about 1 Mbit or less, Correspondingly, two probe assemblies are mounted on the ring plate. In this case, two or more semiconductor chips arranged side by side such that the short sides on which the electrodes are provided are linear are regarded as one semiconductor chip, and the electrodes arranged over a plurality of semiconductor chips on one straight line , A single-layered probe may be formed and attached to a probe mounting body to form a single probe assembly. In this case, since a plurality of semiconductor chips can be simultaneously electrically contacted and an operation test can be performed at the same time, the test time of the semiconductor chips can be shortened.

The ring plate does not need to be circular, and a rectangular opening corresponding to the shape of the semiconductor chip is provided at the center of the board made of the wiring board, and a rectangular ring plate corresponding to the opening is provided. May be used. The opening as described above, the tip of the probe needle,
When aligning the needle with the electrode of the semiconductor chip to be measured,
A needle tip portion and an electrode pattern corresponding to the tip portion are photographed by the imaging device through the opening, and the image is processed to be used for automatic positioning. It is also used for observing the tip of the needle and the surface of the semiconductor chip through an opening with a microscope or the like, and manually adjusting the needle to the first semiconductor chip.

The functions and effects obtained from the above embodiment are as follows. (1) A wiring means corresponding to an electrode provided on one side of a semiconductor chip or a semiconductor device is formed on a flexible wiring board, a connection end side thereof is electrically connected to the wiring means, and a tip end portion is formed on an electrode to be measured. A probe needle bent together is provided, and a needle hole for inserting the bent portion of the probe needle is provided in a film which sandwiches the probe needle together with the flexible wiring board. A probe assembly is formed by attaching an elastic body for imparting a spring property to the tip and pressing the lower surface of the probe mounting body against the lower surface of the probe mounting body from the lower surface side to form a probe assembly. Attach one or more probe assemblies corresponding to the electrodes to the wiring board . In this configuration, the tip of the bent probe needle is inserted into the needle hole of the film, and it is easy to assemble because it can be attached to the probe assembly in a laminated structure with the flexible wiring board and the film, and the tip of the needle connects to the electrode. In this case, stable and good contact can be performed, and most of the signal transmission paths can use wiring means formed on the flexible wiring board, so that the effect of improving signal transmission characteristics can be obtained.

(2) The probe needle does not need to have a spring property to determine the contact pressure by itself, and is fixed by being sandwiched between the tab substrate and the film, so that an extremely thin wire can be used. Accordingly, there is no need to form a tapered taper unlike the conventional probe needle, and the effect of simplifying the processing of the probe needle and arranging a large number of needles at a high density can be obtained. (3) The use of an elastic body such as silicon rubber as the probe and the laminated structure have the effect that the total needle pressure can be averaged and uniformized. Incidentally, in the conventional probe using a probe needle such as tungsten or the like, the needle pressure varies due to the variation in the thickness of each probe needle. (4) The semiconductor chip itself is a piezoelectric element as a whole, and if the mechanical pressure applied to the chip becomes uneven, the element characteristics change due to the piezo effect, and a highly reliable characteristic test result cannot be obtained. Therefore, according to the above (3), an effect is obtained that a highly reliable test result can be obtained. (5) According to the above (1), since the assembling process can be simplified, the effect of reducing the manufacturing cost can be obtained.

Although the invention made by the inventor has been specifically described based on the embodiment, the invention of the present application is not limited to the embodiment, and various modifications can be made without departing from the gist of the invention. Needless to say. For example, the probe may be of any type as long as it has a configuration in which the tip portion is attached to the electrode to be measured and the tip portion is inserted into the guide portion of the film. For example, the probe may be configured so as to linearly extend from the wiring of the tab substrate to the surface of the electrode of the semiconductor chip or the semiconductor device. The wiring provided on the tab substrate (or the flexible wiring substrate) uses a film base as a dielectric, forms the above-described wiring and a conductor acting as a probe on one surface side, and covers the entire other surface side. The known stripline that forms a conductor
line). In such a strip line, at an extremely high frequency, a surface wave is slightly induced on the substrate surface and has an electromagnetic field component in the traveling direction. For this reason, a signal propagating through a strip line is often called a quasi-TEM (quasi-TEM) wave.
The other end of the tab substrate is connected directly to a connector and connected to a cable or the like connected to an IC tester or the like without being connected to the wiring means formed on the board as in the above embodiment. Is also good.

The elastic body for imparting a spring property to the probe needle attached to the probe having the above-mentioned laminated structure is not limited to silicon rubber, and various elastic bodies such as those incorporating a leaf spring along a film base or a tab substrate are used. The following embodiment can be adopted. INDUSTRIAL APPLICABILITY The present invention can be widely used as a probe board for obtaining electrical connection to a small electronic component having a large number of similar electrodes, in addition to electrical measurement of a semiconductor chip formed on a semiconductor wafer.

[0024]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows. That is, a probe in which wiring means corresponding to an electrode provided on one side of a semiconductor chip is formed on a flexible wiring board, a connection end side thereof is electrically connected thereto, and a tip portion is bent to fit an electrode to be measured. A needle is provided, and a needle hole for inserting a bent portion of the probe needle is provided in a film which sandwiches the probe needle together with the flexible wiring board, and these laminated structures have a spring property at the tip of the probe needle. A probe assembly is formed by attaching an elastic body to the probe mounting body so as to be pressed against the lower surface of the probe mounting body from the lower surface side by interposing an elastic body, and corresponding to electrodes on one or a plurality of sides of the semiconductor chip. One or more provided probe assemblies are attached to the wiring board. In this configuration, the tip of the bent probe needle is inserted into the needle hole of the film, and a laminated structure is formed by the flexible wiring board and the film. The signal transmission characteristics can be improved because stable and good contact is made with the wiring means, and most of the signal transmission paths can use wiring means formed on the flexible wiring substrate.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a probe board according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is a bottom view showing one embodiment of the probe board according to the present invention.

FIG. 4 is an enlarged view of a central portion of FIG.

FIG. 5 is a plan view showing another embodiment of the needle holes provided in the film.

FIG. 6 is a top view showing one embodiment of the probe board according to the present invention.

[Explanation of symbols]

Claims (5)

(57) [Claims] 1. A flexible wiring board on which wiring means is formed corresponding to an electrode provided on one side of a semiconductor device, and a connection end side is electrically connected to the wiring means,
A probe having a tip attached to the electrode to be measured, a film provided with the flexible wiring board so as to sandwich the probe, and a guide portion into which the probe is inserted; and a spring at the tip of the probe. The flexible wiring board having the above-mentioned laminated structure, the probe mounting body to which the probe and the film are attached via the elastic body for imparting the property, and the flexible wiring board, the probe and the film having the above-mentioned laminated structure, from the lower side. A probe assembly including a clamping plate that is mounted so as to be pressed against the lower surface of the probe assembly; and a wiring board to which one or a plurality of probe assemblies provided corresponding to electrodes on one or a plurality of sides of the semiconductor device are mounted. A program characterized by Bubodo. 2. The method according to claim 1, wherein the one or more probe assemblies are commonly attached to a ring plate provided at an opening portion of the wiring board by positioning screws, and the other end of the flexible wiring board is connected to the wiring board. 2. The probe board according to claim 1, wherein the probe board is connected to a connection end of a wiring means provided in the probe board. 3. A silicone rubber scan between the flexible wiring board and the film except the portion where the probe is provided
3. The probe board according to claim 1, further comprising a pacer . 4. The probe guide portion provided on the film is formed in a long circle or a comb shape along the direction in which probes are arranged.
Or the probe board of claim 3. 5. The probe board according to claim 1, wherein the wiring means of the flexible wiring board is formed to constitute a microstrip line.