JP2939657B2 - Probe inspection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

 The present invention relates to a probe inspection device.

[Prior art]

When testing whether or not a microcircuit formed on a chip, which is a component of a silicon wafer, is configured as designed, a circuit tester including a signal generator and a waveform analyzer is used. . In this case, the probe tip of the probing card is pressed into contact with the pad formed on the chip, and a test signal is applied from the circuit tester to the fine circuit via the probe tip and the pad to determine whether or not the circuit of the chip is formed. Has been determined. On the other hand, with the recent development of semiconductor VLSI, chips have become larger, and for example, as shown in FIG.
Above, a large rectangular chip 51 having a size of three conventional chips C is formed. This chip 51 has
As shown in FIG. 4, bonding wires (not shown)
Are formed. In order to check the pass / fail of the chip 51, as shown in FIG. 5, the needle 55 of the probing card 54 is placed on the test surface of the pad 52 of the chip 51 placed on a test table 53 having a flat upper surface.
By applying a test signal from a circuit tester (not shown) to the chip 51, it is checked whether or not the circuit configuration of the chip 51 is as designed. Further, as apparent from FIG. 4, the tips of the respective needles 55 are pressed against the respective pads 52.

[Problems to be solved by the invention]

However, for example, as shown in FIG.
Since the stylus 51 and the stylus of the probing card 54 are not parallel to each other, the pad 52
And the balance of the pressing force against the pressure is inconsistent. If a test signal is applied from the circuit tester to the chip 51 in this mismatched state, uniform signal application is not performed, and there is a possibility that the pass / fail of the circuit type of the chip 51 is erroneously determined. The present invention has been made to solve the above problems, and has as its object to provide a probe inspection apparatus in which a chip (subject) and a probing card are parallel to each other.

[Means for Solving the Problems]

In order to achieve this object, the present invention provides a support for supporting a subject, a parallelism detecting means provided above the support for detecting the parallelism between the subject and a probing card, and Parallel control means for moving the subject based on the detection result of the degree detection means to make the subject parallel, and testing means for testing the subject after performing the parallel control by the parallel control means. The control means
A motor for raising and lowering three points on the support table to adjust the inclination in all directions is provided. A part of the inspection means is constituted by the probing card, and the probe tip of the probing card is pressed against the subject. Thus, a trace to be detected by the parallelism detecting means is formed.

[Action]

According to the present invention, first, the probe tip of the probing card is pressed against the test surface of the test subject placed on the support base to form a trace on the test surface. The trace is read by a trace reading unit which is parallelism detecting means. In this case, if the needle tip is pressed against the surface to be inspected in a parallel state, all the traces should be substantially uniform in size,
If they are pressed against each other in a parallel state, for example, the size of the trace should be different between the left and right sides of the surface to be inspected. That is, the test surface is inclined with respect to the probing card. Based on the magnitude of such traces, the inclination determining unit determines the degree of inclination between the probing card and the surface to be inspected, and based on this determination data, the parallel control unit performs an operation for bringing the surface to be inspected and the probing card into a parallel state, The motor is driven based on the calculation result to control the surface to be measured and the probing card to be parallel. When a test signal is applied to the probing card from the circuit tester in a state where the probing card and the test surface are parallel, an accurate signal is applied to the test surface from each probe tip of the probing card.

【Example】

An embodiment of the present invention will be described below with reference to FIGS.
This will be described with reference to the drawings. 3 to 5 are denoted by the same reference numerals, and redundant description is omitted. FIG. 1A is a block diagram for explaining an embodiment of the semiconductor inspection apparatus. As shown in FIG. 1 (A), the X and Y directions (horizontal direction), Z
A sample, for example, a silicon wafer W is placed on a sample table 1 which is a support table that moves in the direction (vertical direction) and the θ direction (rotation direction). Chip 51 is formed (see FIG. 3). The sample stage 1 is arranged on the pedestal 4 and is shown in FIG.
As shown in FIG. 2, servo motors 3a to 3c that constitute a part of the parallel control means are arranged on the vertices of the equilateral triangle in the pedestal 4. The rotation of the output shafts 3d to 3f of the servo motors 3a to 3c, that is, the elevation movement, allows the mounting surface 1a of the sample stage 1 to be tilted in all directions. Above the silicon wafer W, a probing card 54 as a probe constituting a part of an inspection unit driven by a vertical driving unit (not shown)
Is arranged. The probing card 54 has a needle tip of each needle 55 on which the electrode pattern needle tip of the chip 51 is arranged,
The silicon wafer W is pressed against each pad 52 of the chip 51 of the silicon wafer W by moving up and down. After the pressing, the probing card 54 is lifted, for example, upward from the state shown in the figure, and then retracted to the right. An imaging device above the silicon wafer W,
For example, a trace reading unit 5 which is a parallelism detecting means composed of a CCD camera or the like is provided, and light emitted from the lamp 11 is reflected by the pad 52, and based on the reflected light, the light is formed on the pad 52 by the pressure contact. The trace is read as pattern information. The CPU 6 includes an inclination determining unit 6a, a parallel control unit 6b, and the like. The data (pattern) read by the trace reading unit 5 is converted into an electric signal and sent to the inclination determining unit 6a. A control signal is output so that this pattern information becomes a similar pattern at predetermined several points on the silicon wafer surface.
With this output signal, the parallel control unit 6b
The servo motors 3a to 3c are driven via the first to third motor driving units 7a to 7c according to the inclination data determined by 6a, and the output shafts 3d to 3f of the servo motors 3a to 3c are rotationally driven, that is, moved up and down. By moving, the parallelism of the surface of the sample stage 1, ie, the surface of the silicon wafer W is adjusted. The CPU 6 is connected to a ROM 8 storing a program for controlling the entire semiconductor inspection apparatus, and a RAM 9 for temporarily storing processing data. Since the configuration of the semiconductor wafer inspection apparatus is well known to those skilled in the art, the description is omitted here. Next, the operation will be described. With the silicon wafer W positioned at a predetermined position on the sample table 1 placed thereon, the probing card 54 is driven to a predetermined lower position by vertical driving means (not shown), and the sample table 1 is moved upward. The tip of the needle 55 is pressed against the pad 52 of the tip 51 by moving and overdriving. Now, it is assumed that large and small traces are formed on the pads of the selected one chip 51 of the silicon wafer W by the pressing as shown in FIG. That is, large traces A1 to A4 are formed on the pads 52a, 52g, 52h, 52i on the left side of the chip 51, and the traces are B1 to F as going rightward.
1, B4 to F4. From these traces, the probing card 54 and the chip 51 are not in parallel. That is, as shown in FIG. 6, it is determined that the probing card 54 and the chip 51 are closer to the left and farther to the right. This is determined by a pattern recognition technique. The state described above is read as trace data by the trace reading unit 5 as reflected light of the light emitted from the lamp 11 by the pad 52. When the read trace data is sent to the inclination determining unit 6a, the inclination determining unit 6a determines whether the probing card 54 and the chip 51 are in the sixth position based on the trace data.
It is determined that the vehicle is in the inclined state shown in the figure. The parallel control unit 6b determines the probing card 54 based on the judgment data.
Then, an operation for making the chip 51 parallel is performed, and the relative movement, for example, the parallelism of the silicon wafer W is adjusted.
This calculation result is sent to each of the servo motors 3a to 3c as parallel control signals Ha to Hc via the motor driving units 7a to 7c. The servo motors 3a to 3c are rotated forward and backward in response to the parallel control signals Ha to Hc, and the output shafts 3d to 3f are moved up and down accordingly, the sample stage 1 is tilt-controlled, and the probing card 54 is rotated.
And the chip 51 are made parallel to each other. In this parallel state, a predetermined test signal is applied to the pad of the chip from the tip of the probing card 54 by a circuit tester (not shown), and it is determined whether or not the circuit mechanism of the chip is formed as designed. .

【The invention's effect】

As is clear from the above description, according to the present invention, the degree of inclination between the tip of the probing card and the tip is determined based on the size of the trace formed by pressing the tip of the probing card against the tip. Since the judgment is made and the needle of the probing card and the chip are made parallel according to the judgment result, an accurate test signal can be applied to the pad of the chip from the needle tip of the probing card.

[Brief description of the drawings]

1 (A) and 1 (B) are a block diagram and a plan view of a main part of an embodiment of the present invention. FIG. 2 is a plan view showing the size of a trace of a chip. FIG. 3 shows a silicon wafer and a large chip. FIG. 4 is an enlarged view of the above-mentioned large chip, FIG. 5 is a view in which the tip of the needle of the probing card is pressed against the conventional large chip, and FIG. 6 shows a defect of the conventional large chip and the probing card. It is a side view. Description of symbols (1)… Sample stage (support stage) (3a) to (3c) ... Servo motor (3d) to (3f) ... Output shaft of servo motor (5) ... Trace reading part (Parallelism detection Means) (6) CPU (6a)… Inclination determination unit (6b)… Parallel control unit (51)… Silicon wafer chip (subject) (54)… Probing card (55)… Probing Card needle (A) to (F) ... Trace (W) ... Silicon wafer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 21/66 G01R 1/073 G01R 31/26

Claims (1)

(57) [Claims] 1. A support for supporting a subject, a parallelism detecting means provided above the support and comprising an imaging device for detecting the parallelism between the subject and a probing card; A parallel control unit that moves the subject based on a detection result of the unit and parallelizes the subject, and an inspection unit that performs the inspection of the subject after performing the parallel control by the parallel control unit. Is equipped with a motor that raises and lowers three points on the support table to adjust the inclination in all directions. A part of the inspection means is constituted by the probing card, and the probe tip of the probing card is attached to the subject. A probe inspection apparatus characterized in that the probe is pressed to form a trace detected by the parallelism detection means.