JPS5811741B2 - probe board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to inspection and measurement of a monolithic semiconductor integrated circuit device completed on a semiconductor substrate.

This invention relates to a glove board used for.

Conventionally, in the inspection and measurement of a monolithic semiconductor integrated circuit device completed on a semiconductor wafer, for example, as a means for obtaining electrical connection with the input/output terminals of the monolithic semiconductor integrated circuit device, there was a
The technique described as "use of fixed probe card" on page 145 of Electronic Materials (November Special Issue) published on January 5th is publicly known.

This replaces the adjustable multi-point probe and is attached via a mounting piece radially toward the center of the opening in the printed circuit board, at a position corresponding to the electrode (ponding pad) of the wafer chip to which contact is to be made. It has a structure in which a probe needle having a tip bent approximately perpendicular to the electrode surface is fixed.

By the way, on a wafer chip with a size of 4tn x 4mm,
In an LSI (Large Scale Semiconductor Integrated Circuit) with 128 electrodes, the size of one electrode is 70μ×
The spacing between adjacent electrodes is as small as about 70μ, and the distance between the midpoints of both electrodes is about 120μ to 150μ, which is extremely close to each other.

Therefore, the diameter should be about 250μ, and the diameter should be 31mm from the tip.
With conventional probe needles that are tapered from a portion of about tv, adjacent probe needles come into contact with each other and cannot be used for high-density measurements as described above.

Therefore, it is possible to make the probe needles thinner to ensure the spacing (insulation) between the probe needles, but this weakens the springiness of the probe needles, making it difficult to obtain the necessary contact pressure and lacking in durability. In fact, it cannot be put to practical use.

In addition, when soldering a Ueno chip to a ceramic substrate on which external terminals are formed by forming solder bumps on the electrode portions of the wafer chip instead of wire bonding, the thermal expansion coefficients of the wafer chip and the ceramic substrate are different. In order to reduce the mechanical stress of wafer chips, it has been considered to form solder bumps (electrodes) closer to the center of the wafer chip.

In wafer chips with such a configuration, the electrode spacing is narrower and the electrodes are densely formed in multiple rows, and the surface of the solder bumps is approximately spherical, so it is no longer possible to use a fixed probe card with the above structure. I can't.

The present invention has been made in order to provide a probe board that can achieve good alignment and electrical connection with an object to be measured having a high density of measurement points as described above.

The present invention has a small hole that penetrates the upper surface and the lower surface substantially perpendicularly corresponding to the measurement point, and a spring is applied in the axial direction to the small hole of the substrate whose surface including the small hole has at least an insulating property. A probe plate with a structure that has a flexible structure is inserted, is fixed to the substrate on the upper surface side, and is provided with wiring means, and has a tip protruding on the lower surface side. The device is characterized in that it includes an alignment plate having a small hole passing through the alignment plate and the lower surface, and guide means for aligning and superimposing the probe plate on the alignment plate.

Hereinafter, this invention will be explained in detail together with examples.

FIG. 1 is an enlarged sectional view showing an embodiment of the main part of the probe plate according to the present invention.

In the probe plate in this embodiment, a small hole 3 is formed in a substrate 1 made of an aluminum plate, and the small hole 3 is formed in a substrate 1 corresponding to a point to be measured, passing through the upper surface and the lower surface almost perpendicularly. An aluminum oxide film 1a is formed on the surface of the substrate 1 including the aluminum oxide film 1a.

This aluminum oxide film 1a is formed, for example, by so-called alumite treatment, which is a well-known technique for compensating for the corrosion-prone defect of aluminum, and specifically by electrolysis in an oxalic acid solution. .

The aluminum plate was used as the substrate in consideration of workability for forming small holes 3 corresponding to the measurement points with high precision.

However, as it is, insulation between the probes cannot be obtained when inserting the probe into the small hole as described later.
An aluminum oxide film 3 is formed on the surface of the substrate 1 including the small holes 3.
A is formed and its electrical insulating properties are utilized.

A probe consisting of a conductive coil spring 4a and a tipped needle 4b is inserted into the small hole 3 of the substrate 1, and the end of the spring 4a is fixed to the upper surface side of the substrate using the adhesive material 5. It is something that sticks.

The spring 4a and needle 4b are electrically and mechanically connected by welding, soldering, winding, or the like.

Alternatively, the tip of the needle may be made thinner and a stopper may be provided on the lower surface of the substrate 1 to prevent the needle 4b from coming off.

Then, on the upper surface side, a wiring means such as a lead wire 2 is connected to the end of the spring 4a to lead it to an inspection device.

FIG. 2 is a plan view of the probe plate, and as shown in the figure, a large number of upper holes 3 are provided corresponding to bonding pads or solder bumps.

In this embodiment, there are only 40 wafer chips for drawing purposes, but the measurement of wafer chips to be achieved by this invention is as described above, for example, a large number of 120 or more chips, and the intervals between the chips are narrow. A probe as described above is inserted into each small hole (not shown).

Small holes 6 provided around the substrate 1 constituting this probe plate
penetrates vertically through the upper and lower surfaces of the substrate 1,
This is used to perform alignment with an alignment plate, which will be described next.

That is, with the probe plate having the above configuration, the position of the tip of the probe cannot be observed from the top surface side in alignment with the wafer chip during measurement.

Therefore, in order to easily perform this alignment, an alignment plate as shown in FIG. 3 is used.

This alignment plate has small holes 8 formed in an aluminum substrate 7 similar to the above, corresponding to measurement points, and
This small hole 8 is counterbore-shaped to have a so-called grove-like shape with an inclined surface toward the center on the upper surface side, which is the probe insertion side.

This is to facilitate insertion of the probe into the small hole 8 of the alignment plate.

Then, as described above, an aluminum oxide film 7a is formed on the surface including the small holes 8.

Further, a window 18at1ab is formed around the small hole 8,
The wafer chip surface is observed through this window 18at1sb to facilitate alignment of the alignment plate and the wafer chip.

FIG. 4 is a plan view of the alignment plate, and shows the small holes 8
are provided in large numbers in the same pattern as the probe plate.

An insertion rod 9 for positioning is vertically provided on the upper surface of the substrate 7 at a position corresponding to the small hole 6 of the probe plate.

Further, in the substrate 7, in addition to the small hole 8,
A slit 10 is formed in the axial direction (and/or the Y-axis direction).

This is used for alignment adjustment used to align the wafer chip with the X axis (or Y axis).

In this embodiment, as shown in FIG. 5, the above-mentioned alignment plate, which is fixed and crushed to the prober body, is provided on the wafer chip 12 placed on the wafer chuck top 11, and the above-mentioned small Hole 8. Observe the top surface of the wafer chip using a microscope or the like through the slit 10, align the measurement point, for example, the solder bump 13, with the corresponding small hole 8 through the small hole 8, and then attach the probe plate to the alignment plate. The probe and the solder bump are aligned by overlapping them using the alignment guide.

That is, as shown in the schematic diagram of the wafer blowbar shown in FIG.
The wafer chip is moved in the horizontal direction by moving in the direction and rotating in the θ direction, and is moved up and down by a two-stage mechanism.

The alignment plate 7 is fixed to the prober main body 16 at a predetermined position on the upper surface side of the wafer chuck top 11 via a connecting body 15.

Furthermore, an observation means 17 such as a microscope is attached to a predetermined position on the upper surface side of the alignment plate 7.

Therefore, by moving the wafer chuck top 11 in the X-axis direction and observing it through the slit 10, alignment is performed so that the X-axis of the wafer chip arrangement and the slit 10 are aligned in the same direction by adjusting the θ direction. can be done.

Then, alignment is performed by controlling the X and Y stages so that the measurement point such as a solder bump on the chip to be measured first matches the small hole 8 of the alignment plate 7.

During this alignment, the window 18a. Using 18b,
The first chip to be aligned can be easily found.

After this, the alignment holes 6 of the probe plate 1 are inserted into the insertion rods 9 of the alignment plate 7, and the alignment plate 7 and the probe plate 1 are overlapped and fixed by, for example, screws. The tip of the probe is made to protrude through the small hole 8 of the alignment plate 7.

Thereby, the probe and the soldering bump etc. can be aligned.

When performing the above alignment, it is desirable that the wafer chuck top 11 be pushed up in two directions to shorten the distance from the alignment plate to facilitate observation.

Furthermore, when overlapping the alignment plate 7 and the probe plate 1, the wafer chuck top 11 is lowered. The probe is pushed up to connect the probe to the measurement point, such as a solder bump, with the required contact pressure.

Note that alignment with the next wafer chip is automatically performed by moving the chip in the X direction or Y direction by the chip interval.

In this embodiment as explained above, since the probe plate has a structure in which the probes are installed vertically, the small holes into which the probes are inserted can be formed with high accuracy to form the probe tip pattern and the measurement point pattern. It is possible to perform alignment with

In other words, the small hole acts as a positioning guide for the probe, and it is possible to prevent a short circuit between the probes due to horizontal displacement or bending of the tip when crimping the tip to the point to be measured. This enables high-density measurements.

Furthermore, since an aluminum plate with excellent workability is used as the substrate, it is possible to form small holes with a diameter of about 100 μm that are aligned with high precision.

Since an aluminum oxide film is formed on the surface, when inserting the probe into the small hole, the insulation between the probes is maintained, and the surface of the small hole is smooth due to the aluminum oxide film. Therefore, during probing, the vertical movement of the probe needle, which moves up and down using this small hole as a guide, is not impaired.

In addition, in the probe plate having the above structure, since the probe is attached perpendicularly to the substrate, the tip of the probe and the measurement point of the wafer chip cannot be observed at the same time.

Therefore, using an alignment plate with small holes and alignment slits having the above-mentioned probe pattern (which is also the wafer chip measurement pattern), the wafer chip surface is measured through the small holes and slits of this alignment plate. can be observed, and alignment between the alignment plate and the wafer chip can be achieved.

By superimposing the probe plate on this alignment plate, the probe plate and the wafer chip can be easily aligned.

The present invention is not limited to the above-mentioned embodiments, and the substrate constituting the probe plate and the alignment plate may be any substrate as long as it has excellent workability and has at least its surface insulated. As for the structure of the needle, one that uses a bamboo shoot spring as a means to provide springiness in the axial direction, or one that uses a bamboo shoot spring itself as a probe, etc. can be used.

Furthermore, the alignment method when overlapping the alignment plate and the probe plate is to form an insertion rod on the probe plate and provide a corresponding insertion hole in the alignment plate, or as shown in FIG. To,
The probe plate and the alignment plate may be connected at a hinge portion 9' so that they are overlapped.

Furthermore, it is possible to form marks on the alignment plate, to form small holes corresponding to the marks on the probe plate, and to align the two while observing with an observation means. It's okay.

Moreover, the shape and number of windows 18a and 18b can be changed in various ways.

In addition to measuring the wafer chips formed at high density, the glove board according to the present invention has a plurality of semiconductor chips each having various circuits configured thereon, and has wiring and external electrodes that connect each semiconductor chip using thin film technology. Wiring of the above-mentioned ceramic substrate when one composite ultra-LSI (large-scale integrated circuit) is obtained by directly connecting the formed ceramic substrate with wire bonding or solder bumps and integrally sealing them. It can be widely used for measurements with high density and a large number of measurement points, such as probe boards used for checking.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of a probe plate showing an embodiment of the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is an enlarged sectional view of a positioning plate showing an embodiment of the invention. , FIG. 4 is a plan view thereof, FIG. 5 is an enlarged sectional view of the object to be measured, FIG. 6 is a schematic diagram of a wafer prober, and FIG. 7 is a globe showing another embodiment of the present invention. FIG. 3 is a side view of the board. 1...Substrate, 1a...Aluminum oxide film, 2...Lead wire, 3...Small hole,
4a... Spring, 4b... Needle, 5...
...Fixing material, 6...Small hole, 7...Substrate, 8...Small hole, 9...Insertion rod, 9'
...Hinge part, 10...Slit, 11.
...Wafer chuck, 12...Wafer chip, 13...Solder bump, 14...
Stage mechanism, 15... Connection body, 16...
...Prober body, 17...Observation means, 18a
t1sb...window.

Claims (1)

[Claims] 1. A substrate having a small hole extending substantially perpendicularly through an upper surface and a lower surface corresponding to a measurement point, and at least a surface including the small hole having an insulating property. A probe with a springy structure is inserted into the probe plate, which is fixed to the board on the top side and provided with a wiring means, and a tip protrudes from the bottom side, corresponding to the above measurement points. 1. A probe board comprising: an alignment plate having a small hole penetrating an upper surface and a lower surface; and guide means for aligning and superimposing a probe plate on the alignment plate. 2. A probe board according to claim 1, wherein the small hole provided in the alignment plate has an inclined surface facing the center on the probe insertion side.