JPS61125031A - Probe card - Google Patents

Abstract

PURPOSE:To cope with multi-pinning of an IC and to easily cope with a probe test in a high frequency band by raising up a probe needle in a ground conductor, too. CONSTITUTION:A signal pad 12 in a pellet 11 of a wafer is contacted with a signal probe needle 5, and a ground pad 13 is contacted with a ground probe needle 9. A communication with a tester IC of a wafer probe is had by a closed circuit of a signal conductor 3, a signal probe needle 5, a signal pad 12, an IC, a ground pad 13, a ground probe needle 19 and a ground conductor 6. As, in this case, a ground probe needle 7 is exclusively provided besides a signal probe needle 5, and a distance between each ground probe needle 7 and an earth terminal 10 on the probe card is arranged equally in length, a pass length in each closed circuit becomes equal. Therefore, an impedance between each closed circuit becomes equal and a probe test in a high frequency band is effectively made without a hitch.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a probe card, and particularly to one that is effective for probe testing in high frequency bands.

[Background technology]

In the manufacture of semiconductor devices (hereinafter referred to as IC), a signal conductor is formed on the outside of an insulated substrate, and a ground conductor is formed inside, as a probe card used for probe testing with a wafer blower. A device configured to secure a grounding probe needle by standing the probe needle upright and electrically connecting the number of signal conductors necessary for grounding to the grounding conductor via through-hole conductors. Conceivable.

However, in such a probe card, the number of signal probe needles allocated decreases, which goes against the trend of increasing the number of pins in ICs. The inventor of the present invention has revealed that there is a problem in that a difference in impedance occurs, making probe testing in a high frequency band insufficient.

An example of a wafer blower mentioned is the "Electronic Materials November 1982 Special Edition" published by Kogyo Chosenkai Co., Ltd.
Published on November 18, 1981, there are pages 227 to 231.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a probe card that can cope with the increase in the number of pins of an IC and can easily handle probe tests in high frequency bands.

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.

[Summary of the invention]

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

That is, by erecting a probe needle also on the ground conductor, the signal probe needle and the ground probe needle can be used independently.

[Embodiment] FIG. 1 is a partially cutaway plan view showing a probe card according to an embodiment of the present invention, FIG. 2 is a bottom view thereof, and FIG. 3 is an enlarged partial longitudinal sectional view thereof.

In this embodiment, the probe card includes an insulating substrate, and the insulating substrate 1 is formed into a substantially rectangular flat plate with a multilayer structure using an insulating material such as glass epoxy resin. A large window hole 2 for image recognition is provided approximately at the center of the insulating substrate 1.

A large number of signal conductors 3 are wired radially around the window hole 2 on the bottom surface of the insulating substrate 1, and through-hole conductors 4 are formed in the signal conductors 3 at predetermined positions to penetrate the insulating substrate 1 to the top surface. It is formed to do so. A single signal probe needle 5 is arranged at the end of each signal conductor 3 on the window hole 2 side, and one end of each signal conductor 3 is welded and mechanically and electrically connected. The fifth group is arranged annularly along the window hole 2 and protrudes radially toward the center of the window hole 2.

A grounding conductor 6 is formed in the form of a thin film over almost the entire surface of the insulating substrate 1, and a relief portion 7 is provided at a position corresponding to the through-hole conductor 4 of the grounding conductor 6. They are each set up to avoid short circuits. An exposed portion 8 is formed around the window hole 2 of the ground conductor 6 in an annular shape by cutting out the upper peripheral portion of the window hole 2 of the insulating substrate l, and this exposed portion 8 has a plurality of wires. A ground probe needle 9 is welded at one end and is mechanically and electrically connected.

The three groups of signal conductors and the ground conductor 6 have impedances of communication closed circuits of a predetermined value (for example, 50 ohms).
The mutual path resistance values, insulation gap values, etc. are set in a microstrip line relationship so as to match.

Next, the effect will be explained.

When the probe test is performed, the pellet 11 of the wafer
The signal probe needle 5 is on the signal pad 12 in
The grounding probe needles 9 are brought into contact with the grounding pads 13, respectively.

Communication between the wafer blower tester and the IC is through a closed circuit through the signal conductor 3, signal probe needle 5, signal pad 12, IC, ground pad 13, ground probe needle 9, and ground conductor 6. Each is performed by

Here, the characteristics of a closed circuit will be considered in the case where some of the signal probe needles are used as ground probe needles.

Now, suppose that the two signal probe needles 5a and 5b at different positions in FIG. flows through
Since it flows to the ground of the signal generation source of the probe needle 5a, impedance matching by the microstrip cannot be achieved, which causes problems especially in probe tests in high frequency bands.

However, in this embodiment, a ground probe needle 7 is provided exclusively in addition to the signal probe needle 5, and the distances of each ground probe needle 7 from the ground terminal 10 on the probe card are equal. Therefore, the path lengths of each closed circuit are equal to each other. Therefore, the mutual impedance of each closed circuit is equal,
Probe tests in high frequency bands can also be carried out effectively without any problems.

〔effect〕

By providing a dedicated grounding probe needle in addition to the signal probe needle, there is no need to divert the signal probe needle to the grounding probe needle, making it possible to secure a large number of signal probe needles. This makes it possible to cope with the increase in the number of pins of an IC.

(2) By arranging a dedicated grounding probe needle, the impedance between the signal line and the ground can be matched with the impedance of the signal system, so even high frequency band probe tests can be performed effectively.

(3) By exposing the grounding conductor in an annular manner around the opening of the window hole, each grounding probe needle can be arranged at a desired position.

(4) By configuring the signal conductor and the ground conductor in a microstrip line relationship, impedance matching can be precisely set, so the reliability of the probe test can be further improved.

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

For example, instead of arranging the signal conductor on the outside and the ground conductor on the inside, the signal conductor may be arranged on the inside and the ground conductor on the outside.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway plan view showing a probe card according to an embodiment of the present invention, FIG. 2 is a bottom view thereof, and FIG. 3 is an enlarged partial i-plane view thereof. 1... Insulating board, 2... Front window hole, 3... Signal conductor,
4...Through-hole conductor, 5...Signal probe needle, 6...Ground conductor, 7...Escape part, 8...
Exposed part, 9... Grounding probe needle, 10... Earth terminal, 11... Bellet, 12... Signal pad, 13... Grounding pad.

Claims (1)

[Claims] 1. A signal conductor is provided on either the outside or inside of the insulating substrate,
A grounding conductor is formed on the other side, and a part of the conductor formed inside has an exposed part, and a probe needle is connected to this exposed part. A probe card with a probe needle connected to the conductor. 2. The probe card according to claim 1, wherein the signal conductor and the ground conductor are configured to have a microstrip line relationship.