JP2559242B2 - Probe card - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a probe card.

(Prior Art) In general, a probe card is arranged in a probe device or the like and is used as a connection body for electrically wiring an inspected element formed on a semiconductor wafer, for example, an inspected element such as an IC chip electrode pad and a tester. Has been.

In recent years, the integration of IC chips has been advanced due to the innovation of the miniaturization technology, and the number of terminals constituting the IC chip has been increased.
The number of electrode pads per chip is increasing. When inspecting an IC chip having this increased number of electrode pads, a probe contact device such as a probe card technology is also required. For example, a probe card having an increased number of probe terminals is required. As a means for increasing the number of probe terminals of this probe card, there has been proposed one in which the probe terminals are mounted substantially perpendicularly to the device under test. For example, JP-A-60-189949 and JP-A-61-154137
JP-A No. 61-205870, JP-B No. 62-44365 and the like propose a probe in which a probe terminal is vertically fixed to a substrate wired so as to be electrically conductive, and JP-B-58-11741.
No., Mitsui Sho 57-4755, Mitsui Sho 58-148935, Mitsukoshi Sho 59-1
In Japanese Patent No. 2615, Japanese Utility Model Publication No. 62-36139, etc., there is proposed one in which a substrate wired so as to be electrically conductive and a probe terminal are connected via an elastic body such as a conductive spring.

(Problems to be solved by the invention) However, in the case where the probe terminal is vertically fixed to the above-mentioned substrate, the probe terminal and the DUT are brought into contact with each other at the time of inspection, the probe is further overdriven. There is a problem that the terminals are damaged by distortion and the probe terminals become brittle and lack in durability.

As a countermeasure for this problem,
Some of them are connected via an elastic body such as a conductive spring, but if they are connected via a spring or the like, the electrical conductivity is poor and accurate inspection cannot be performed, and the probe card manufacturing also has a complicated configuration. Therefore, it is difficult to attach minute parts, and it takes a long time for accurate manufacture, and lacks versatility.

The present invention has been made to solve the above problems, the probe can be arranged at a fine pitch corresponding to the fine-pitch electrode pads formed on the device under test, and the durability is excellent and the reliability is high. Moreover, it is an object of the present invention to provide a probe card that can extremely easily position the probe with respect to the measurement end.

[Structure of Invention]

(Means for Solving the Problems) A probe card of the present invention is a probe that is arranged corresponding to the measurement end of a device to be inspected and is made of a coaxial cable, and that the probe is fixed and held together with an optical fiber from the peripheral surface. In addition, a holding member formed of a transparent insulating member that distributes the contact pressure when the probe comes into contact with the measurement end, and a support body that supports the holding member from the outer peripheral surface are provided. It is a feature.

(Operation and Effect) According to the present invention, the probe can be easily aligned with the measurement end such as the electrode pad through the transparent holding member when inspecting the device to be inspected. When the probe comes into contact with the measuring end of the inspected element, not all of the contact pressure with the measuring end of the probe is applied to the probe, and it is distributed as shear stress to the holding member that holds the probe fixed, and the holding member becomes It elastically deforms and reduces the contact pressure of the probe. When the holding member elastically deforms, since the holding member is supported from the outer peripheral surface by the support, the holding member is deformed in the vertical direction by the step stress caused by the contact pressure from each probe, and the position deviation of the probe is caused. Can be prevented. Further, by irradiating the element to be inspected with light from the optical fiber, the holding member is transparent, so that each probe can be extremely easily aligned with the corresponding measurement end. Therefore, the probes can be arranged at a fine pitch corresponding to the fine-pitch electrode pads formed on the object to be inspected, and the durability and reliability are high, and the probe can be positioned very easily with respect to the measurement end. It is possible to provide a probe card that can do this.

(Example) Next, one example of the probe card of the present invention will be described with reference to the drawings.

First, as shown in FIG. 1, the configuration of the probe card (1) corresponds to the arrangement pattern of the electrode pads (3) of the IC chip which is the measurement end formed on the measured object, for example, the semiconductor wafer (2). At the position, a material (e.g., elastically deformable tungsten) and a probe (4) having a diameter of, for example, 80 [mu] m and a tapered input / output terminal are provided. Each probe (4) is made of elastically deformable electrically insulating resin such as silicone synthetic resin, fluororesin, polyethylene resin and other thermoplastic resin (hereinafter represented by silicone synthetic resin) (5). It is held perpendicular to the semiconductor wafer (2). The side surface of the silicone synthetic resin holding each probe (4) is supported by a support body which does not elastically deform so as to surround the silicone synthetic resin (5), for example, a ceramic side body (6). Here, as shown in FIG. 1 (B), the probe (4) is configured to be substantially vertical from the inside of the silicone synthetic resin (5) to the position where it is led out to the wafer (2) side. Then, the contactor (4) led out from the other end side is provided with, for example, a probe (not shown) on an electrically conductive conductor pattern (not shown) formed on the upper surface of the side body (6) made of ceramics. 4) is bent and wired. One end of the conductor pattern is wired to a terminal connected to a tester (not shown) that is an inspection and measurement device for the object to be measured. Also, as described above, the probe (4)
In case of wiring without bending, the probe (4) is constructed almost vertically in the silicone synthetic resin (5) and in the lead-out portions on both sides, and a film having a conductor pattern is installed on the tester connection side. You may wire.

Next, a method for manufacturing the above-mentioned probe card (1) will be described.

First, for example, a guide plate (7) for vertically guiding the probe (4) is provided on the upper surface and the lower surface of a side body (6) made of ceramics having a circular hole in the center and having a thickness of, for example, about 10 mn. Arrange in parallel. Each of the guide plates (7) is made of, for example, stainless steel, and has a small hole (about 100 μm in diameter) at a predetermined position, that is, at each position corresponding to the arrangement pattern of the electrode pads of the IC chip, for example. 8) are provided in large numbers. The small holes (8) of the guide plates (7) provided on the upper surface and the lower surface are coaxially provided. Here, the probe (4) is inserted into each of the coaxial small holes (8) provided in each of the guide plates (7), and the tip, that is, the free end is, for example, from the guide plate (7) on the lower surface side. It is set to derive about 300 μm. After setting all the tips (4), the side body (6)
Also, each probe (4) is held in the space (9) formed by the two guide plates (7) arranged on the upper and lower surfaces, and the contactor (4) contacts the electrode pad (3). In order to distribute the contact pressure at that time to the elastic force of the probe (4), a liquid resin, for example, a silicone synthetic resin, flows in through an opening (10) previously provided in the upper guide plate (7). After this inflow, the silicone synthetic resin (5) is cured at room temperature while maintaining the above state. In order to shorten the curing time, it may be cured at a high temperature using an oven or the like. After the silicone synthetic resin (5) is cured, the guide plates (7) respectively arranged on the upper and lower surfaces of the side surface body (6) are separated from the silicone synthetic resin (5). In order to facilitate the peeling, it is desirable to apply a release agent on the contact surface of the silicone synthetic resin (5) of each guide plate (7) before the liquid silicone synthetic resin (5) flows in. After peeling off each guide plate (7), the probe (4) extending to the upper surface side is curved and connected to, for example, soldered to the conductor pattern formed on the upper surface of the side surface body (6), and the probe card ( 1) is completed.

Next, the above-prepared probe card (1) is placed in a probe device (not shown) which is a measuring device for the semiconductor wafer (2), and an operation action in the measurement of the semiconductor wafer (2) will be described.

First, an object to be measured, for example, a semiconductor wafer (2) is installed at a position facing the probe card (1). Here, the wafer (2) and the probe card (1) are moved relative to each other in the vertical direction, for example, the wafer (2) is raised, and the tip of each probe (4) of the probe card (1) and the wafer (2) are moved. 2) is brought into contact with the electrode pad (3). Here, further wafer (2)
, I.e., overdrive, e.g. 60-100μ
take m. By this overdrive, the oxide film or the like adhered to the electrode pad (3) of the wafer (2) is destroyed at the tip of the probe (4), and the tip of the probe (4) and the conductive portion of the electrode pad (3). Make an accurate connection with the agent. At this time, for protection, each probe (4) is distributed upward by the elastic force of the probe (4) and the elastic force of the silicone synthetic resin (5) in the vertical direction. Here, the elastic deformation of the silicone synthetic resin (5) is caused by the ceramic side body (6), the elastic force of the resin, the distance between the probe (4) and the side body (6), and the silicone synthetic resin (5). The elastic deformation in the lateral direction is suppressed by adjusting the thickness of the above and the adhesive force of the silicone synthetic resin (5) to >>>.

In the connection state as described above, the test signal output from the tester (not shown) is input to the input electrode of the IC chip by the probe (4).
From the other contactor (4) to the tester, and the electrical signal generated on the electrode pad (3) of the IC chip is applied to the tester, and the quality and function level of the IC chip are compared with the signal based on the tester. judge. After completion of the inspection measurement, the wafer (2) is lowered by a predetermined amount. This brings the probe (4) and the electrode pad (3) into a non-contact state. At this time, the probe (4) returns to its original position due to the elastic deformation of the silicone synthetic resin (5).

As described above, the probe is held by an elastically deformable material, and the contact pressure of the probe contacting the measuring end is distributed to the contactor and the above material so that the probe can be moved in the vertical direction. Since the height position of the needle is reproducible, the height position of the probe is always set at an accurate height, and the reliability can be improved.

In particular, when a silicone synthetic resin is used as the elastically deformable material, the silicone synthetic resin has inorganic and organic characteristics and the main skeleton of the compound bond is a siloxane bond (Si-O-Si).
Therefore, it has excellent heat resistance, electrical insulation and water resistance, and is transparent, which facilitates the alignment of the probe and the electrode pad.

The present invention is not limited to the above-mentioned embodiment, and the material of the probe is not limited to tungsten and may be any material having a good electric conductivity.

Further, as shown in FIG. 3, the probe (4) may be coated (11) in order to enhance the electrical characteristics. Here, gold plating may be coated (11) to improve conductivity, and Teflon (trade name) or the like may be coated (1) to enhance insulation resistance.
1) OK. Further, a cone-shaped blanker (1) is attached to the contacting position of the electrode pad (3) of the contactor (4) to assist the adhesive force due to the vertical movement of the contactor (4).
2) may be provided.

Further, as shown in FIG. 4, by configuring the probe (13) with a coaxial cable, it is possible to avoid superposition of electrical noise at the probe (13). In addition, this probe (1
4) and optical fiber cable (1) in the center of silicone synthetic resin (5) (center surrounded by multiple probes (14))
By mounting 4) vertically, if the element to be inspected is a light receiving element or the like, the silicone synthetic resin (5) is transparent by illuminating the element to be inspected with light from the optical fiber cable (14). Together, the electrode pad (3) can be easily visually confirmed, and each probe (13) can be extremely easily aligned with the corresponding electrode pad (3).

Furthermore, as shown in FIG. 5, it is possible to inspect a plurality of IC chips to be inspected at the same time as the arrangement configuration of the probe (4) or an insult having a large number of electrodes. In this case, a silicone synthetic resin is used. In order to obtain the same elastic force in (5), it is possible to make the distance between each side contactor (4) from the side face body (15) equal. In particular, if the probes are arranged so as to correspond to the arrangement of the electrode pads (3) of all the IC chips formed on the wafer (2), the wafers (2) can be collectively measured and the throughput is improved.

Furthermore, the object to be measured may be an LCD substrate or the like instead of a semiconductor wafer, and the same effect can be obtained even if it is used as a test fixture used for inspecting a printed circuit board.

Further, the curved portion of the probe may be coated with electrically insulating Teflon (trade name) or the like so that the insulating state can be maintained even when the curved portions come into contact with each other.

Furthermore, as shown in FIG. 6, a printed board (16) is provided on the outer periphery of the side surface body (6) provided with the probe (4) and the silicone synthetic resin (5).
Each probe (4) held by the above-mentioned silicone synthetic resin (5) is attached to each conductor pattern (17) wired to the connection terminal of the tester (not shown) provided in 6).
The same effect as that of the above-described embodiment can be obtained even if the wiring is curved and bonded, for example, soldered.

Furthermore, as shown in FIG. 7, a printed board (16) is provided on the outer periphery of the side surface body (6) provided with the probe (4) and the silicone synthetic resin (5).
Conductor patterns (17) wired to the connection terminals of a tester (not shown) provided in 6) in an insulated state.
When wiring each probe (4), each probe (4) is provided vertically, and an FPC (Flexible Print Circuit) (18) with a conductor pattern provided on the upper surface of this probe (4) is provided. Arranged,
The probe (4) and the conductor pattern (17) of the printed board (16) may be wired.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a probe card for explaining an embodiment of the present invention, FIG. 2 is a diagram for explaining the manufacture of the probe card of FIG. 1, and FIGS. 3, 4, 5 FIG. 6, FIG. 6 and FIG. 7 are diagrams showing other examples of FIG. 1 ... probe card, 4 ... probe 5 ... silicone synthetic resin, 6 ... side body 7 ... guide plate, 8 ... small hole

Claims (2)

(57) [Claims] 1. A probe, which is arranged corresponding to the measuring end of an element to be inspected and is composed of a coaxial cable, and a probe which is fixedly held together with an optical fiber from the peripheral surface and which is in contact with the measuring end. A probe card comprising: a holding member formed of a transparent insulating member to which contact pressure is distributed; and a support body that supports the holding member from the outer peripheral surface. 2. The probe card according to claim 1, wherein the insulating member is a silicone synthetic resin, a fluororesin, polyethylene or a thermoplastic resin.