JPS62123732A - Probe card - Google Patents

Abstract

PURPOSE:To supply a host computer with signals, outputted by a circuit under inspection, already after preparatory processing accomplished while traveling through an inspection circuit by a method wherein said inspection circuit is built in a probe card itself. CONSTITUTION:A water 2 is subjected to inspection that is accomplished with a probe card 1 attached to a wafer prober. In an inspection process, the point of a probe 5 protruding from a prober main body 3 is caused to abut against a pad 22 of a pellet 21 installed on a wafer 2 that is the object of inspection, which establishes electrical contact between the pad 22 and probe 5. The signals outputted by the pellet 21 of the pad 22 are applied through the probe 5 to an inspection circuit 12 formed on a probe wafer 11. In the inspection circuit 12, a prescribed preparatory inspection us performed, which is accomplished on the basis of said outputted signals. The signals are outputted by the inspection circuit 12 as inspection data. The inspection data arrive at a host computer after traveling through a bump electrode 7b, wiring layer 8 belonging to the probe main body 3, and an external output cable 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a technique that is effective when applied to a probe card, and particularly to a probe card that tests the circuit of each pellet formed on a semiconductor wafer.

[Background Art] In order to inspect the circuit formation state of each verve l-8N region formed on the surface of a semiconductor wafer (hereinafter simply referred to as wafer), an auxiliary tool having a plurality of contacts called a probe card is placed on the wafer. It is known that the probe card contacts a predetermined position and sends a signal via a cable connected to the probe card to a large host computer into which a test program has been input in advance, thereby inspecting the quality of the pellet.

By the way, when a wafer is inspected using a probe card having the above structure, if the distance between the probe card and the host computer is large, a predetermined length of the connection cable is also required.

However, as the cable becomes longer, the waveform of the signal extracted from the pellet becomes distorted while being transmitted through the cable, and the signal transmission speed also slows down, leading to problems such as inaccurate testing and reduced testing efficiency. The present inventor has clarified that there is.

A detailed example of wafer inspection technology using a probe card is given in "Electronic Materials November 1983 Special Issue, VLSI Manufacturing and Testing Equipment" published by Kogyo Research Association Co., Ltd., November 15, 1983. Guidebook”, P1
95 to P198 [Object of the Invention] An object of the present invention is to provide a probe card that can perform accurate and highly efficient wafer inspection.

Another object of the present invention is to downsize a wafer inspection system.

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.

In other words, by having a structure in which the test circuit is formed on the probe card itself, the output signal from the circuit under test can be transmitted to the host computer in the state of preprocessed information via the test circuit. Accurate information can be transmitted without causing waveform distortion even if

Moreover, this makes it possible to prevent signal delays caused by cables.

Furthermore, by forming the test circuit on the probe card itself, the test system can be made smaller.

[Embodiment 1 LID is a sectional view showing a probe card according to an embodiment of the present invention, and FIG. 2 is a plan view thereof.

The probe card 1 of the first embodiment is used to inspect the quality of the signal output state of each pellet formed on a wafer 2 as an object to be inspected. It is in a state where it has been formed.

The probe body 3 is made of, for example, silicon carbide (S
iC), etc., and has a donut-shaped planar shape with a probe hole 4 in the center.

A plurality of contacts, that is, probe needles 5 are provided protruding from the periphery of the probe hole 4 in a predetermined direction.

The probe needle 5 is electrically connected to a bump electrode 7a provided on the front side by a through-hole wiring 6 that penetrates the probe body 3 in the front and back directions. Further, a predetermined wiring layer 8 is formed near the peripheral edge of the probe body 3, one end side of this wiring layer 8 is connected to the bump electrode 7b, and an electrode 9 is formed on the other end side. An external output cable 10 is connected to the electrode.

On the other hand, a bump electrode 7a is provided on the surface side of the probe body 3.
, 7b, the probe wafer 11 is attached with its circuit-forming surface facing the front surface of the probe body 3. A test circuit 12 corresponding to the output signal taken out from the probe needle 5 is formed on the circuit forming surface of the probe wafer 11, and the test circuit 12 has its input/output side electrically connected to the bump electrodes 7a, 7b. It is connected. In addition,
This test circuit 12 is formed through steps such as oxidation and diffusion, similar to the manufacturing of normal semiconductor device wafers. Note that an inspection hole 13 is formed in the center of the probe wafer 11 in correspondence with the probe hole 4 of the probe body 3;
In the first manufacturing process, the test circuit 12 may be opened before or after the test circuit 12 is formed.

The probe card 1 obtained as described above is attached to, for example, a wafer prober (not shown), and the wafer 2 is inspected. That is, in the inspection work, first, the tip of the probe needle 5 protruding from the probe body 3 is
The pads 22 of each pellet 21 on the wafer 2, which is the object to be inspected, are brought into contact with each other to establish an electrical connection between the pads 22 and the probe needles 5. The output signal from the pad 22 of the pellet 21 is transmitted to the probe wafer l via the probe needle 5.
The signal is sent to a test circuit 12 formed on the top of the circuit.

Here, a predetermined pretest is performed based on this output signal, and the output signal is output from the test circuit 12 as predetermined test information. This inspection information is sent to a host computer (not shown) via the bump electrode 7b, the wiring layer 8 of the probe body 3, and the external output cable 10.

As described above, according to this embodiment, the inspection circuit 12 is formed on the probe card l itself, that is, the probe wafer 11 mounted on the probe body 3, and the inspection circuit 12 is formed on the probe card l itself, that is, on the probe wafer 11 mounted on the probe body 3, and the test circuit Since the wafer is inspected, converted into inspection information, and output, the host computer can perform accurate and highly efficient wafer inspection without being affected by the external output cable IO.

[Effects] (1) By using a probe card structure in which a test circuit corresponding to each signal output of the test object is formed, the output signal from the test circuit passes through the test circuit and the information state is preprocessed. can be transmitted to the host computer via a cable, without causing any distortion in the waveform.
Accurate information can be transmitted.

(2) According to (1) above, wafer inspection can be performed accurately.

(3) According to (1) above, test information can be transmitted to the host computer in a pre-processed state, so signal delays due to cables can be prevented.

(4) By forming the test circuit on the probe card itself, the scale of the host computer can be reduced, and as a result, the entire test system can be made smaller.

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, although the test circuit has been described as being formed on a wafer, the present invention is not limited to this, and the test circuit may be mounted as a semiconductor device packaged on the probe body.

[Field of Application] In the above explanation, the invention made by the present inventor was mainly applied to the field of application, which is a probe card for inspecting semiconductor wafers. However, the present invention is not limited to this, and for example, This technique is also effective when applied to probe cards used for testing other electronic devices.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a probe card according to an embodiment of the present invention, and FIG. 2 is a plan view showing a probe card according to the embodiment. DESCRIPTION OF SYMBOLS 1... Probe card, 2... Wafer, 3... Probe body, 4... Probe hole, 5... Probe needle, 6... Through-hole wiring, 7a, 7b... Bump electrode , 8... Wiring layer, 9... Electrode, 10... External output cable, 11... Probe wafer, 12...
-Test circuit, 21...Bellet, 22...Pad. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. A probe card characterized in that a test circuit corresponding to each signal output of an object to be tested is formed. 2. The probe card according to claim 1, wherein the test circuit is formed on a semiconductor substrate. 3. The probe card according to claim 1 or 2, which is a probe card for inspecting semiconductor wafers.