JPH0669057B2 - Wafer prober device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a wafer prober device used in a semiconductor wafer inspection process, and particularly to a position inspection of a probe needle of the wafer prober device.

[Prior Art] FIG. 5 is a block diagram showing a portion of a conventional wafer prober device, particularly a portion for inspecting the position of a probe needle, as shown in, for example, JP-A-60-213040. In the figure, (1) is a probe needle, (2) is a probe card provided with the probe needle (1), and (3)
Is the wafer under test, (4) is the wafer (3) mounted on X,
A wafer chuck that moves in the Y, Z, and θ directions, and (5) is a microscope that captures the probe needle (1) and the wafer (3). FIG. 6 is a plan view of the probe needle (1) and the wafer under test (3) of the wafer prober device shown in FIG. 5 as seen from above, and (1a) and (1b) are misaligned needles. , (31) is a chip pattern in the wafer (3), (32) is an electrode in the chip pattern (31), and in particular (32a) and (32b) are located on the misaligned needles (1a) (1b), respectively. The corresponding electrodes are shown.

Next, the operation will be described. The wafer (3) mounted on the wafer chuck (4) is moved under the probe needle (1). Here, the operator uses the microscope (5)
The tip of all probe needles (1) and the chip pattern (31) in the wafer (3) are visually recognized, and the relative position between the electrode (32) in the chip pattern (31) and the probe needle (1) is detected by a sensing operation. The joystick lever (not shown) or the like, and the wafer chuck (4) is moved to X,
The electrode (32) and the probe needle (1) are moved in the Y and θ directions so as to be aligned with each other. If it is confirmed that the tip positions of the probe needles (1) are present in all the electrodes (32) in this state, the position of the probe needles (1) is judged to be good. However, like the probe needles (1a) and (1b) in FIG. 6, even if the relative alignment is performed, if the tip is not located in the electrode (32), the probe needle (1a) ) And (1b) are determined to be defective.

[Problems to be Solved by the Invention] As described above, since the probe needle position inspection in the conventional wafer prober apparatus is a sensitive work by the operator, there is a high possibility that an inspection error may occur, and depending on the operator. There were problems such as variations in inspection results.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a wafer prober device that automatically inspects the position of a probe needle without requiring an operator.

[Means for Solving Problems] A wafer prober device according to the present invention detects a tip end position of a urobe needle by using a television camera, and stores position information and an in-chip electrode of a wafer under test stored in advance. The relative position of these is calculated from the positional information of the probe needle tip thus obtained, and the probe needle position is inspected.

[Operation] In the present invention, the tip position of the probe needle is detected by using the television camera, and the tip position of the probe needle and the tip position of the tip of the chip are calculated by calculation based on the position information of the in-chip electrode of the wafer under test stored in advance. Since the relative position with respect to the electrode position is obtained and the probe needle position is inspected, the position inspection can be performed automatically and with high accuracy.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. First
FIG. 1 is a block diagram showing an embodiment of a wafer prober device according to the present invention, particularly showing a portion for inspecting the position of a probe needle. In the figure, (1) is a probe needle, (2) is a probe card provided with the probe needle (1), (3) is a wafer under test, and (4) is a wafer (3) mounted on X, Y, and Z. , A wafer chuck that moves in the θ direction, (6) a television camera located above the probe needle (1), (7) an XY direction moving mechanism section that moves the television camera (6) in the XY directions, (8)
Is a pattern recognition processing unit for pattern recognition of the image of the probe needle (1) taken by the television camera (6), and (9) is a probe needle (1) based on information from the pattern recognition processing unit (8). The tip position of the probe is calculated with high accuracy, and the relative position between the tip of the probe needle (1) and the tip electrode is calculated based on the tip electrode position information stored in the information storage section (9a). This is a calculation control unit that calculates. The arithmetic control unit (9) also controls the position of the television camera (6) and adjusts the magnification through the XY movement mechanism unit (7). Also, FIG. 2 (a) is a plan view of the tip position of the probe needle recognized, and FIG. 2 (b).
Shows a plan view of the in-chip electrode position of the well to be tested.

Next, the operation will be described. First, TV camera (6)
Is moved to a position where the visual field (S) in FIG. 2 (a) can be captured, and the magnification is adjusted. The image taken by the TV camera (6) is transmitted to the pattern recognition processing unit (8),
After the pattern recognition processing, the position of the needle tips (N ₁ ) and (N ₂ ) is recognized by the arithmetic control unit (9), and this is temporarily stored in, for example, a memory (not shown) in the arithmetic control unit (9). To be done. Next, the TV camera (6) is sequentially moved, and all needle tip positions (N ₁ ) (N ₂ ) ...
Recognize (N ₁₂ ). This needle tip position information and second
Based on the position information (indicating the center position of the electrode) of the electrodes (P ₁ ) (P ₂ ) ... (P ₁₂ ) stored in the information storage unit (9a) in advance as shown in FIG. The arithmetic control unit (9) performs the following processing. This will be described with reference to FIG. 3. First, the needle tip positions (N ₁ ) (N ₂ ) ... (N ₁₂ ) in the recognition coordinate system of the television camera (6) are fixed, and the electrode position coordinate system is set. When rotated and translated, the sum of the distances ▲ ▼ (see FIGS. 2 (a) and (b)) between the needle tip positions and the electrode positions Σ ▲ ▼ (however, n = 1, 2, ... 12) Δθ and ΔX, ΔY that minimize the value of
Calculate the value of. Next, a region (A ₁ ) (A ₂ ) ... corresponding to the size of the electrode centered on the electrode position (P ₁ ′) (P ₂ ′) ... (P ₁₂ ′) when moved by Δθ, ΔX, ΔY. (A ₁₂ ), set the needle tip position (N ₁ ) in each area.
(N ₂ ) ... It is determined whether (N ₁₂ ) is located. Third
In the case of the figure, since the needle tip position (N ₁₀ ) is not located in the area (A ₁₀ ), this needle is judged to be in the wrong position. As described above, the position inspection of all needles is automatically performed. For these operations, for example, the arithmetic control unit (9) has a program (not shown) built-in,
It is done according to this. An example of the operation flowchart is shown in FIG.

The needle tip position (N ₁ ) in the above embodiment
(N ₂ ) ... (N ₁₂ ) and electrode position (P ₁ ) (P ₂ ) ... (P ₁₂ ). The amount of deviation of both coordinate systems when the sum Σ ▼ of each distance ▲ ▼ becomes the minimum. The method for obtaining Δθ, ΔX, and ΔY can be directly used for automatic alignment between the electrode and the tip of the needle.

[Effects of the Invention] As described above, according to the present invention, the needle tip position is detected by using the television camera, and the needle tip position is inspected by comparing it with the in-chip electrode position of the controlled wafer stored in advance. Since the above-mentioned procedure is performed, there is an advantage that an operator is not required and the needle tip position can be inspected automatically and more reliably.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a wafer prober device according to the present invention, FIG. 2 (a) is a plan view of a probe needle seen from above, and FIG. 2 (b) is a chip pattern of a wafer under test. FIG. 3 is a plan view seen from above, FIG. 3 is an explanatory diagram showing the inspection method of the present invention, FIG. 4 is a flow chart diagram of a program incorporated in the arithmetic control unit, and FIG. 5 is a configuration diagram showing a conventional wafer prober device. FIG. 6 is a plan view of the probe needle and the in-chip electrode of the wafer showing the visual inspection situation. In the figure, (1) is a probe needle, (2) is a probe card, (3) is a wafer under test, (4) is a wafer chuck, (6) is a television camera, (7) is an XY direction moving mechanism section, ( 8) is a pattern recognition processing unit, (9) is a calculation control unit, and (9a) is an information storage unit. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] 1. A television camera positioned above a probe card provided with a plurality of probe needles for probing a wafer to be tested and photographing the probe card, and pattern recognition of an image of each probe needle photographed by the television camera. The pattern recognition processing unit and the position control of the television camera are performed, and the probe needle tip position is calculated and confirmed with high accuracy based on the information from the pattern recognition processing unit. Based on the in-chip electrode position information stored in advance in the storage unit, the electrode position where the total amount of displacement between each probe needle tip and each in-chip electrode when the probe needle tip position is fixed is the minimum Arithmetic control unit that operates according to a built-in program for obtaining movement amounts Δθ, ΔX, and ΔY of the coordinate system And a wafer prober device. 2. A television camera located above a probe card provided with a plurality of probe needles for probing a wafer to be tested and photographing the probe card, and pattern recognition of an image of each probe needle photographed by the television camera. The pattern recognition processing unit and the position control of the television camera are performed, and the probe needle tip position is calculated and confirmed with high accuracy based on the information from the pattern recognition processing unit. An electrode position coordinate system that minimizes the amount of displacement between each probe needle tip and each tip electrode when the probe needle tip position is fixed based on the tip electrode position information stored in advance in the storage unit. The amount of movement Δθ, ΔX, and ΔY of the electrode is obtained, and the electrode when the electrode position coordinate system is moved according to these movement amounts A wafer prober apparatus comprising: an arithmetic control unit that operates according to a built-in program, that detects a needle position defect depending on whether the position and the tip position of each probe needle are within a predetermined deviation amount.