JPH02172249A - Jig for inspecting probe - Google Patents

Abstract

PURPOSE:To prevent influence of noise caused by a transmission system connected to a probe by a method wherein signal transmission between the probe and respective inspection machines is performed by using optical fiber cables. CONSTITUTION:A plurality of optical fiber cables 1 are used, which are to be connected to inspection machines and an optic fiber cable connector 2 on a probe. Therefore, a signal from a signal generator or the like is output to the optical fiber 1, and an electric signal is supplied to a probe 5 for supplying signal with photoelectric conversion at its end 3 and printed on a specimen 11 to be inspected. On the other hand, an electric signal output from the specimen 11 is photoelectrically converted at a signal processing unit 4 immediately after it exits from the probe 5 for outputting, and the optical signal is applied to a measurement input unit of an inspection machine via the optical fiber 1. This enables signal transmission to be performed by optical signals so that the signal is completely free from influence of noise and measurement accuracy may not deteriorate.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to technology for improving the performance of probes connected to signal generators, signal analysis devices, etc., and in particular, to improving the performance of probes used for testing ultra-high frequency ICs. and technology suitable for achieving multifunctionality.

[Conventional technology]

Probe inspection techniques in the semiconductor manufacturing process are described in Japanese Patent Application Laid-Open No. 55-44708.

In addition, in the past, it has been used to contact a specific point of an object to be inspected or measured such as a semiconductor wafer, and to supply a signal to this input point from a signal generator, or to input signals and information from the measurement point into a signal analysis device. , probes are used.

This probe consists of a holder made of insulating material and placed above the object to be inspected, and a probe needle supported by the holder and whose tip can come into contact with a specific part of the object to be inspected. and a coaxial cable is further connected to the probe needle.

By the way, the present inventor has studied probe testing of ICs in a high frequency band.

The following are the techniques studied by the present inventor, and the outline thereof is as follows.

For example, in the inspection of ICs, an inspection system as shown in FIG. 4 has conventionally been used. A plurality of probe needles 21 are pressed against a plurality of predetermined points on the wafer 20 from above, and the probe needles 21 are fixed to a performance pod 22 . Power is supplied to the performance port 22 from the IE source device 23, and a number of connectors 24 corresponding to the number of testing devices are attached.
The data generator 26 and the analyzer 2
An inspection device such as No. 7 and the probe needle 21 are connected.

A coaxial cable with a specified characteristic impedance (for example, 50 ohms) is used for electrical connection to the probe body in order to achieve impedance matching with the input line and output line of the above inspection equipment and to prevent noise from entering. It is being

[Problem to be solved by the invention]

However, as the coaxial cable between the inspection equipment and the probe needle becomes thicker, the length of the cable becomes longer, and the frequency handled becomes higher, a problem arises in that noise is more likely to be picked up through the coaxial cable. If noise enters the signal line, there is a problem in that the analysis accuracy in an analyzer or the like is significantly reduced.

An object of the present invention is to provide a probe inspection technique that can prevent the influence of noise caused by a transmission system connected to a probe section.

Another object of the present invention is to provide a probe inspection technique in which signal processing can be performed in the probe section.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means to solve the problem]

A brief overview of typical inventions disclosed in this application is as follows.

That is, the signal transmission between the input probe needle for supplying signals to the test object and the output probe needle for extracting the operation signal of the test object based on the signal supply result, and the inspection equipment is carried out. This is done using optical fiber cables.

[Effect]

According to the above-mentioned means, a signal from a signal generator or the like is output to an optical fiber, and at the end of the optical fiber, an electrical signal is supplied to a signal supplying probe needle through optical-to-electrical conversion, and is applied to the object to be inspected. On the other hand, the electrical signal output from the object to be inspected is subjected to electrical-to-optical conversion immediately after exiting the output probe needle, and the optical signal is applied to the measurement unit of the inspection equipment via an optical fiber. Therefore, since the signal transmission to the probe needle is performed by an optical signal, it is not affected by noise at all, and measurement accuracy is not degraded.

〔Example〕

FIG. 1 is a plan view showing an embodiment of a probe inspection jig according to the present invention, and FIG. 2 is a cross-sectional view taken along the line -■ of the embodiment shown in FIG.

The optical fiber cable 1 is connected to the inspection equipment shown in FIG. 4 and the optical fiber connector 2 of the probe section, and a plurality of optical fiber cables are used. For example, the cable can be laid in approximately the same position as a conventional coaxial cable, and its length can be approximately the same. The number of optical fiber connectors 2 corresponding to the number of optical fiber cables 1 is arranged in a circle on the performance pod 9 so as to surround the wafer 11. This optical fiber connector 2 has a group connected to a signal supply side device (for example, the data generator 26 shown in FIG. 4) and a measurement side device that processes signals from the probe side (for example, the data generator 26 shown in FIG. 4). The signal processing unit 3 is connected to the connector 2 on the supply side (input side), and the signal processing section 3 is connected to the connector 2 on the measurement side (output side). A processing section 4 is connected.Signal processing section 3
and the signal processing section 4 are interconnected by a bus 10 so that they can exchange information with each other and other signal processing sections.

As shown in FIG. 2, the signal processing unit 3 receives the light emitted from the signal supplying device via the optical fiber cable 1 and converts the light into
A photodiode 31 for electrical conversion, the photodiode 3
1, and a signal processing circuit 33 that is interconnected with each of the other signal processing sections 3 and 4 to exchange control signals and data signals. There is.

Both the signal processing section 3 and the signal processing section 4 are installed on the performance port 9 adjacent to the optical fiber connector 2. The probe needle 5 electrically connected to the signal processing section 3 and the signal processing section 4 is made such that its tip can come into contact with a predetermined position of the wafer 11, and the opening 6 ( The wafer 11 is held toward the center of the hole (a hole opened so that the wafer 11 can be visually recognized).

The signal processing section 4 also includes a signal processing circuit 41 that is interconnected with the signal processing section 3 and other signal processing sections 4 to exchange control signals and data signals;
An amplifier 42 that amplifies the output signal of the amplifier 42, and a light emitting diode 43 that performs electrical-to-optical conversion (light emission) according to the output voltage of the amplifier 42.

The probe needle 5 has a power probe needle for supplying power to the power line of the wafer 11 in addition to the signal probe needle connected to the signal processing circuit 33, 41, and the lead wire 7 is connected to this power probe needle. It is connected. Furthermore, a power supply electrode 8 is provided at the upper side end of the performance port 9, and a lead wire from a power supply device 23 shown in FIG. 4 is connected to this power supply electrode 8.

Next, the operation of the embodiment with the above configuration will be explained with reference to FIG.

First, the wafer 11 is fixed on the wafer chuck 12, and then the performance pod 9 and the wafer 11 are moved relative to each other, and the tips of the probe needles 5 are set so as to coincide with the inspection position of the wafer 11.

In this state, power is supplied from the power supply device to the power supply electrode 8, and as shown in Fig. 2, an optical signal is generated from the signal supply side equipment (data generator, etc.) (although not shown, the signal supply side An electrical-to-optical conversion unit is provided between the signal output end of the device and the optical fiber cable 1), then the optical signal is transmitted through the optical fiber cable 1, reaches the optical fiber connector 2, and is further transferred to the photodiode. The light is received at 31. The photodiode 31 generates an electric signal corresponding to the brightness of the optical signal, and this signal is amplified by an amplifier 32 and processed by a signal processing circuit 33, and the signal is applied to the probe needle 5.

When a signal is applied to the wafer 11 from the probe needle 5 in this way, a voltage corresponding to the operating state of the IC is detected in the measurement probe needle 5 that is in contact with the pad of the IC, and the voltage is The signal is applied to the signal processing circuit 41. The signal processing circuit 41 processes the input terminal and supplies it to the amplifier 42, and the light emitting diode 43 emits light according to the output voltage of the amplifier 42. By comparing the light emitting state with a light emitting state estimated in advance, it is possible to determine whether the wafer 11 is good or bad. Although not shown, the analyzer is provided with a conversion unit that performs optical-to-electrical conversion of the optical signal from the optical fiber cable 1.

As described above, by using the optical fiber cable 1 that transmits optical signals instead of electrical signals as a signal transmission medium, there is no electrical transmission system interposed between the probe section and the inspection equipment. be able to. Therefore, since there is no noise caused by impedance mismatching as in the conventional case, no erroneous measurements occur. Furthermore, since it is not affected by noise, it can also be used in ultra-high frequency bands.

In addition, since the signal processing section 3 and signal processing section 4 can be installed in the probe section, the probe section itself has a signal processing function, so data processing can be performed on the performance board 9, making inspections using the probe faster and more multifunctional. It can be carried out.

As above, the invention made by the present invention has been specifically explained based on the examples, but it goes without saying that the present invention is not limited to the above-mentioned examples and can be modified in various ways without departing from the gist thereof. Nor.

In the above explanation, the invention made by the present inventor was mainly explained in terms of its field of application, which is a probe inspection jig for inspecting wafers, but it is not limited to this. It can also be applied to inspection jigs for printed circuit boards with components mounted on them.

〔Effect of the invention〕

Among the inventions disclosed in this application, the effects obtained by typical ones are as follows.

That is, the signal transmission between the input probe needle for supplying signals to the test object and the output probe needle for extracting the operation signal of the test object based on the signal supply result, and the inspection equipment is carried out. By using an optical fiber, it is possible to eliminate noise generated between the inspection equipment and the probe needle, which prevents erroneous measurements and enables use in an ultra-high frequency range.

Further, by providing a signal processing section in the probe section, multifunctionality of probe inspection can be achieved.

[Brief Description of the Drawings] Fig. 1 is a plan view showing an embodiment of the probe inspection jig according to the present invention, Fig. 2 is a cross-sectional view taken along the arrow ■-■ of the embodiment shown in Fig. 1, and Fig. 3 is a plan view showing an embodiment of the probe inspection jig according to the present invention. FIG. 2 is a front sectional view showing how the inspection jig is used, and FIG. 4 is a front sectional view showing a conventional probe inspection jig. DESCRIPTION OF SYMBOLS 1... Optical fiber cable, 2... Optical fiber connector, 3.4... Signal processing unit, 5... Probe needle, 6... Opening, 9... Performance port,
10...Bus. Fig. 1 Fig. 3 Fig. 2 Fig. 774 謬弘benden 1 Fig. 4 70: No.

Claims (1)

[Scope of Claims] 1. A probe that supplies a signal to an object to be inspected through an input probe needle, and applies a resulting operation signal of the object to be inspected to a measuring device via an output probe needle. 1. A probe testing jig, characterized in that signal transmission between each of the probe needles and testing equipment including the measuring device is performed using an optical fiber. 2. Claim 1, characterized in that optical-to-electrical conversion or electric-to-optical conversion is performed at a site close to each of the probe needles.
Probe inspection jig as described. 3. The probe inspection jig according to claim 1, wherein a data processing circuit section is connected to each of the probe needles.