JPS6246268A - Probe card - Google Patents

Abstract

PURPOSE:To improve the reliability of measured values in a high frequency operation by optically interchanging signals between a sample and a measuring instrument. CONSTITUTION:A probe card 1 is comprised of a rectangular-plate-shaped circuit board 2 and a cylindrical insulative member 3 fixed to the through-hole 2a of the board 2 and a plurality of light/electricity converting elements 4 and electricity/light converting elements 5 are arranged in the thick wall portion 31 of the member 3. When outputted from a measuring instrument, a light signal passes through a light transmitting cable 6 and is irradiated onto the elements 4. The elements 4 convert the light signal to an electric signal to output and input it to the electrical input portion of a sample via a wiring 33 and a measuring electrode 32. On the other hand, an electric signal produced from the circuit of the sample is inputted to the elements 5 via another measuring electrode 32 and another wiring 33. The elements 5 convert the electric signal to a light signal to output and input it to the measuring instrument via the cable 6. Thus, the electric characteristics of the sample are measured and the reliability of measured values can be improved especially in a high frequency operation.

Description

Detailed Description of the Invention 1. The present invention relates to a probe card used to measure the electrical characteristics of various electronic components as samples, and particularly relates to a probe card that is used to measure the electrical characteristics of various electronic components as samples. The present invention relates to a probe card that allows signals to be exchanged from a sample to a measuring device via a measuring electrode using an optical transmission cable.

Failure analysis and measurement of electrical characteristics of electronic components such as integrated circuits and thermal print heads formed on semiconductor wafers as strain samples are generally performed using a measuring device called a blower set. This blower set uses a probe card equipped with probes arranged in accordance with the arrangement of electrical input/output parts (bonding band parts) of the sample to be measured.

Here, the probe card shown in FIG. 2 will be explained as a conventional technique. FIG. 2 is a sectional view showing the configuration.

In the figure, 21 is a circuit board on which various heel electronic components and the like are mounted (not shown), and printed wiring is provided. An opening 22 is provided in the center of this circuit board 21, and a fitting part 23 is formed on the back side of this opening 22. An insulating ring 24 having an inclined surface is fitted into the fitting part 23, and a plurality of needle-shaped probes 25 serving as measurement electrodes are arranged radially on this inclined surface. The needle 25 is held by an insulating synthetic resin 26.Furthermore, on the front and back surfaces of the circuit board 21,
Printed wiring 27 is arranged so as to extend radially outward from the vicinity of the insulating ring 24. The probe 25 is connected to the end of the printed wiring 27 on the insulating ring 24 side by soldering or the like. Note that the printed wiring 27 provided on the front side is omitted in the drawing.

Then, the probe card is connected to a measuring device called a probe (not shown), and the probe 25 is directly pressed against the surface of the electrical input/output section of the sample, and various electrical characteristics are measured by exchanging signals. I try to do this.

By the way, since signals are exchanged between the electrical input/output section on the sample and the prober via the probe 25 and the printed wiring 27, the probe 25 and the printed wiring 27 The wiring 27 inevitably inserts an inductance component and a capacitance component between the electrical input/output section of the sample and the measuring device, resulting in impedance mismatch. Furthermore,
Generally, it is difficult to shield the printed wiring 27,
As a result, the induced noise components have a large effect on the measured waveform. For these reasons, with conventional probe cards, the reliability of measured values has been unavoidably lowered, especially during high frequency operation.

This invention was devised in view of the above circumstances, and the purpose is to provide a probe card that can minimize impedance mismatch and noise components and improve the reliability of measured values, especially during high frequency operation. There is.

In order to achieve the above-mentioned object of "low-counting", the present invention is configured to optically exchange signals between the sample and the measuring device. An optical transmission cable was provided on the circuit board instead of wiring.

An insulating member was attached to this circuit board, and an electric/optical conversion element and an optical/electrical conversion element for converting electricity into light and light into electricity were arranged on this insulating member. Each of these elements was arranged to face the distal end surface of the optical transmission cable. Furthermore, measurement electrodes were provided on the lower surface of the insulating member to be connected to each of the elements through extremely short wiring. Note that since this measurement electrode is brought into contact with the electrical input/output section of the sample to be measured, it is formed to correspond to the arrangement of the electrical input/output section.

When sending a signal from the dish measuring device to the sample, the optical signal output from the measuring device is transmitted to the vicinity of the measuring electrode via an optical transmission cable. The transmitted optical signal is converted into an electrical signal by an optical/electrical conversion element disposed near the measurement electrode. This electrical signal is applied to the electrical input/output section of the sample via the measurement electrode.

On the other hand, the electrical signal output from the sample is converted into an optical signal by an electrical/optical conversion element disposed in the vicinity of the measurement electrode via a measurement electrode different from the one described above. This optical signal is given to the measuring device side via an optical transmission cable.

dog J1 masu FIG. 1 is a sectional view of a main part showing an embodiment of the present invention.

In the figure, reference numeral 1 denotes a probe card, and the probe card 1 includes a substantially rectangular plate-shaped circuit board 2 and a cylindrical insulating member 3 fixed to a through hole 2a of the circuit board 2.

Specifically, the insulating member 3 is fixed to protrude from the lower surface of the circuit board 2 coaxially with a through hole 2a formed in the center of the circuit board 2. Thick part 31 of this insulating member 3
Inside, a plurality of holes 31a are formed bent in a substantially doglegged shape. At the center of this hole 31a, there is an optical/electrical conversion element 4 that converts light into electricity and electricity into light.
A plurality of electrical/optical conversion elements 5 are arranged. The optical/electrical conversion element 4 may be, for example, a high-speed switching element or a light-emitting element capable of intermittent light at high speed, while the electric/optical conversion element 5 may be, for example, a light-receiving element capable of following high-speed intermittent light. It is desirable to employ high-speed switching elements, respectively.

Therefore, below the hole 31a in which the optical/electrical conversion element 4 and the electric/optical conversion element 5 are formed, the element 4 is
．． 5 and the measuring electrode 3 connected by an extremely short wiring 33
2 are arranged. In this embodiment, the measuring electrode 32 is a rod-shaped contact bottle 3 whose lower end is rounded.
21 and a resilient member 322 such as a coil spring interposed between the upper end of this contact bin 321 and the lower end of each element 4.5. That is, although the contact pin 321 is always elastically biased downward by the resilient member 322, the contact pin 3 is not attached to the stepped portion of the hole 31a.
Since the flange of 21 is caught, the contact bottle 321 will not come out downward. The reason why the measurement electrode 32 is configured as described above is that when the contact bottle 321 is brought into contact with the electrical input/output section of the sample, the elastic member 322 contracts and pushes the contact bottle 321 upward. Mitigating the impact on the electrical input/output section-U
It's for the sake of it. It goes without saying that this measurement type wide 32 is arranged in accordance with the arrangement of the electrical input/output section (bonding pad section) of the sample such as various electronic components to be measured. The contact pin 321 constituting the measurement electrode 32 is made of, for example, tungsten, phosphor bronze alloy, or the like.

Further, an optical transmission cable 6 such as an optical fiber is inserted into the hole 31a of the insulating member 3 on the other side. The distal end surface of the optical transmission cable 6 faces the upper surfaces of the optical/electrical conversion element 4 and the electric/optical conversion element 5 with a small distance therebetween. The other end of the optical transmission cable 6 is led out along the upper surface of the circuit board 2 to a measuring device called a blower (not shown). Generally, a measuring device outputs an electrical signal, and in order to convert the electrical signal into an optical signal externally, the electrical/optical conversion element/t described above or the optical/electrical It is necessary to arrange an element similar to the conversion element 5 on the circuit board 2, for example. In this case, the optical transmission cable 6 may be led out to the element. Note that if the electrical signal is converted into an optical signal and the optical signal is directly output within the measuring device, the optical transmission cable 6 may be introduced into the measuring device.

When using the probe card 1 described above, the exchange of signals between the measuring device and the sample is as follows. First, when an optical signal is output from the measuring device, this optical signal passes through the optical transmission cable 6 and passes through the optical/electrical conversion element 4.
is irradiated. This optical/electrical conversion element 4 converts the optical signal into an electrical signal, outputs it, and inputs it to the electrical input/output section of the sample 2 via the wiring 33 and the measurement electrode 32. On the other hand, the electrical signal output from the sample circuit is sent to a measurement electrode 3 different from the one described above.
2. Input to the electrical/optical conversion element 5 via the wiring 33.

This electrical/optical conversion element 5 converts the electrical signal into an optical signal, outputs it, and inputs it to the measuring device through the optical transmission cable 6. In this way, the electrical opening characteristics of the sample are measured.

Note that the measurement electrode 32 in this invention is of course not limited to that described in the above embodiment. According to the measurement electrode 32 configured as in the embodiment, there is an effect that scratches fg are less likely to be attached to the electrical input/output portion of the sample.

As explained above, in the probe card according to the present invention, the elements forming the inductance component and the capacitance component have only extremely short wiring connecting the optical/electrical conversion element and the electric/optical conversion element and the measurement electrode. Therefore, the inductance component and capacitance component are almost negligible, and impedance mismatch can be minimized. Moreover, pudding 1~
Since the wiring is an optical transmission cable and no electrical signals are passed through the optical transmission cable, no noise components are generated.

Based on the above, according to the present invention, it is possible to improve the reliability of measured values, especially during high frequency operation.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing an embodiment of the present invention, and FIG. 2 is a sectional view showing the structure of a conventional probe card. ■...Probe card, 2...Circuit board, 3...
Insulating member, 32... Measurement electrode, 4... Optical/electrical conversion element, 5... Electrical/optical conversion element, 6... Optical transmission cable. Patent Applicant Japan Electronic Materials Co., Ltd. Agent Patent Attorney Takaharu Ohnishi No. 17 +7'11-AgarY

Claims (1)

[Claims] (1) A circuit board on which an optical transmission cable for exchanging signals between the electrical input/output section of the sample to be measured and the input/output section of the measuring device is installed, and an insulating member to which the tip of the optical transmission cable is fixed; and an insulating member arranged on the lower surface of the insulating member in accordance with the arrangement of the electrical input/output section of the sample and brought into contact with the electrical input/output section. a plurality of measurement electrodes, a plurality of optical/electrical conversion elements and electrical/optical conversion elements that are disposed on the insulating member so as to face the distal end surface of the optical transmission cable and that convert light to electricity and electricity to light; A probe card characterized by being equipped with an element.