JPS6231825B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for testing semiconductor wafers,
In particular, it relates to a method of bonding a semiconductor wafer and an electrical property testing probe (hereinafter referred to as a probe).

1 and 2 are schematic diagrams of conventional semiconductor testing equipment for testing semiconductor wafers. In the figures, 1 is a fixed stage, 2 is a first guide rail attached to the fixed stage 1, and 3 is this first guide rail. 1 A first movable stage guided in the X-axis direction (horizontal direction in FIG. 1) on a guide rail 2; 4 a second guide rail attached to the first movable stage 3; 5 a second guide rail. A second movable stage 6 is guided on the second movable stage 4 in the Y-axis direction, and the rotation angle can be adjusted.
A chuck top 7 is mounted and fixed on the chuck top 6 and is freely guided in the XY direction together with the second movable stage 5, and a semiconductor wafer to be tested; 7a is a semiconductor wafer formed in large numbers on the semiconductor wafer 7; , 7b is a plurality of electrode pads formed on the semiconductor element 7a, 8 is a test head which has an opening 8a in the center and is placed opposite to the fixed stage 1, and 9 is attached to the lower surface of the test head 8. , an adapter card having an opening 9a concentric with the opening 8a of the test head 8, 1
0 is a probe card made of a donut disk-shaped insulating substrate that is rotatably set in the opening of this adapter card 9, and 11 is a probe card that has one end planted on the insulating substrate of this probe card 10 and the other end that has an opening in the center. A plurality of probes are mounted in the portion 10a so as to be arranged in accordance with the pattern of the electrode pads 7b; 12 is an angle adjustment knob for adjusting the rotation angle of the probe card 10; 13;
14 is a microscope installed above the opening of the test head 8 in order to simultaneously observe the tip of the probe 11 and the electrode pad 7b; 14 is a microscope on which the semiconductor wafer 7 placed and rotated is placed on the chuck top 6; This is a control section that stores and controls the direction and movement position of the chuck top 6.

In the semiconductor test equipment configured in this way,
The electrode pad 7b and the probe 11 are joined as follows.

First, the first semiconductor wafer 7 to be subjected to a characteristic test placed on the chuck top 6 is fixed to the chuck top 6 under the control of the control section 14, and the mounting angle is corrected in a predetermined direction. After this, the probe card 1 is guided from the mounting position by the first and second guide rails 2 and 4.
Move to the adjustment position directly below 0. Next, microscope 13
Accordingly, the probe 11 and the electrode pad 7b of one of the semiconductor elements 7a formed on the semiconductor wafer 7 are observed and the posture is adjusted. This attitude adjustment is performed by moving the chuck top 6 on the first and second guide rails 2, 4 in the X-Y direction,
An electrode pad 7 is placed directly below the tip of each probe 11.
b so that they are facing each other. Next, the probe 1 is applied to the electrode pad 7b set in a predetermined direction.
If there is an angle deviation of 1, the probe card 10 is rotated using the angle adjusting knob 12 to adjust the angle of the probe 11 to the electrode pad 7b.
At this time, to correct the deviation in the X-Y direction between the probe 11 and the electrode pad 7b caused by adjusting the angle of the probe card 10, adjust the chuck top 6 again and align the electrode pad 7b so that it faces the probe 11. Let's do it. This chuck top 6 X-Y
The direction adjustment and the angle adjustment of the probe card 10 are repeated until each electrode pad 7b and each probe 11 face one-on-one. After the attitude adjustment of the probe 11 and the electrode pad 7b with respect to one of the semiconductor elements 7a formed in large numbers on the semiconductor wafer 7 in this way, that is, the facing alignment is completed, the chuck top 6 is raised, and the probe 11 and the electrode The pad 7b is then joined to conduct desired characteristic tests. In this way, after the characteristic test of one semiconductor element 7a on the semiconductor wafer 7 is completed, the X-Y
The electrode pads 7b of the individual semiconductor elements 7a and the probes 11 are aligned in sequence under the control of the control unit 14, which stores the arrangement positions in the directions, and each time the chuck top 6 moves upward and joins. is also done automatically.

Furthermore, by storing the XY position of the chuck top 6 at the time when the facing alignment is completed in the control unit 14, the second and subsequent semiconductor wafers 7 of the same lot can be placed on the chuck top 6. Simply by operating the control section 14, the electrode pads 7b and the probes 11 are automatically aligned and bonded to each other.

However, in this device, the probe 11 and the electrode pad 7 visible below it can be seen through the microscope 13.
Since positioning is performed while simultaneously observing .b, there has been a problem with semiconductor devices 7a, which have recently become highly integrated. For example, with the advent of semiconductor elements 7a having more than 100 electrode pads 7b, more than 100 corresponding probes 11 are required, and in observation using the microscope 13 according to the conventional method, Since the field of view was blocked, it was not possible to observe the electrode pad 7b underneath.
Therefore, there was a drawback that the electrode pad 7b and the probe 11 could not be aligned facing each other.

The present invention has been made in view of the above-mentioned drawbacks, and involves placing a semiconductor wafer and a probe at adjusted positions shifted from each other, and photographing the main surface of a semiconductor element formed on the semiconductor wafer with a first TV camera. Insert the contact part from the tip of the probe into the second
The images are taken with a TV camera, and while displaying these images superimposed on the same screen, the relative posture is adjusted to match the image of the electrode pad of the semiconductor element and the image of the bonding surface of the probe. The object of this invention is to facilitate alignment of electrode pads of a semiconductor element having electrode pads and a probe.

An embodiment of the present invention will be described below based on the schematic diagrams of a semiconductor testing apparatus shown in FIGS. A television camera 16 for photographing the chip for photographing the electrode pad 7b of the semiconductor element 7a at the adjusted position is attached to the lower part of the opening 1a of the fixed stage 1 formed directly below the probe 11. A television camera for photographing a probe that clearly photographs only the portion where the probe 11 is joined to the electrode pad 7b of the semiconductor element 7a, that is, the tip portion, 17 is an eyepiece of the television camera 16 for photographing the probe, and 18 is an eyepiece of this television camera for photographing a probe. It is a monitor cross line drawn on the lens 17,
It is in a parallel relationship with the first guide rail 2 and the second guide rail 4, and serves as an indicator to see that the semiconductor element 7a and the probe 11 are maintained in a parallel relationship. Reference numeral 19 denotes a monitor television that displays images of the electrode pad 7b and the probe 11 taken by the chip photographing television camera 15 and the probe photographing television camera 16, respectively, in a superimposed manner on the same screen.

Next, in the semiconductor testing apparatus constructed in this way, the electrode pads 7b of the semiconductor wafer 7 and the probes 11 are bonded together as follows.

First, as in the conventional example, the first semiconductor wafer 7 to be subjected to a characteristic test is placed on the chuck top 6 and is fixed to the chuck top 6 under the control of the control section 14, and is placed in a predetermined direction. After the placement angle is adjusted, it is moved from the placement position to directly below the probe card 10. Next, the chip top 6 is moved to an adjustment position directly below the chip photographing television camera 15, and at this position, the image of the semiconductor element 7a photographed by the chip photographing television camera 15 and the probe photographed by the probe photographing television camera 16 are displayed. A relative posture adjustment is performed by observing a monitor television 19 on which images of the contact portion side of 11 are displayed in a superimposed manner. At this time, the semiconductor element 7a and the probe 11 are each focused and photographed, so a clear image is displayed on the monitor television 19. Since only the joint surface with the pad 7b is displayed on the monitor television 19, it is convenient for relative posture adjustment. This posture adjustment is performed by moving the chuck top 6 to the first and second positions.
Move it on the guide rails 2 and 4 in the X-Y direction,
The position is adjusted so that the image of the electrode pad 7b overlaps the image of the probe 11. Next, if there is an angular deviation of the image of the probe 11 with respect to the image of the electrode pad 7b set in the determined direction,
Probe card 1 by angle adjustment knob 12
0 to align the angle of the image of the probe 11 with the image of the electrode pad 7b. To correct the deviation in the X-Y direction between the image of the probe 11 and the image of the electrode pad 7b caused by adjusting the angle of the probe card 10, the image of the electrode pad 7b is superimposed on the image of the probe 11 by adjusting the chuck top 6 again. Adjust the position accordingly. The adjustment of the chuck top 6 in the X-Y direction and the angle adjustment of the probe card 10 are repeated until the image of each electrode pad 7b and the image of each probe 11 overlap one-on-one as shown in FIG. In this way, when the image of the electrode pad 7b photographed by the television camera 15 for chip photography and the image of the probe 11 photographed by the television camera 16 for probe photography are superimposed one-on-one, the actual separation distance between the two is: This is the same distance as the separation distance between the chip photographing television camera 15 and the probe photographing television camera 16. Therefore, when the position of the chuck top 6 when the image of the probe 11 and the image of the electrode pad 7b are aligned is used as a reference point, and the chuck top 6 is moved in parallel by the above-mentioned separation distance in the direction of the TV camera 16 for photographing the probe, the electrode pad 7b is It is placed in a position facing the probe 11 one-on-one. After raising the chuck top 6 and joining the probe 11 and the electrode pad 7b,
This is to perform a characteristic test of the semiconductor element 7a.
The position of the chuck top 6 when the relative posture adjustment is completed based on the images of the monitor television 19, the storage of the distance between the chip photographing television camera 15 and the probe photographing television camera 16, and the movement control of the chuck top 6 are all controlled by the control section 14. It is carried out by. Therefore, the electrode pad 7b related to one of the many semiconductor elements 7a formed on the semiconductor wafer 7
After the relative alignment of matching the image of the probe 11 with the image of the probe 11 is completed, the arrangement position of the semiconductor elements 7a group on the semiconductor wafer 7 in the XY direction and the distance between the above relative position and the opposing position are determined. Under the control of the control section 14 which has stored the above, the electrode pads 7b of the individual semiconductor elements 7a and the probes 11 are aligned in order, and the chuck top 6 moves upward each time to automatically perform the bonding. Therefore, all the semiconductor elements 7a formed on the semiconductor wafer 7 can be tested automatically. Further, under the control of the control unit 14 which stores the position of the chuck top 6 at the time when the relative attitude adjustment is completed, the second and subsequent semiconductor wafers 7 of the same lot are also placed on the chuck top 6 and controlled. Part 1
4, the electrode pad 7b and the probe 11 are automatically aligned and bonded to each other.

In the above embodiment, before adjusting the relative posture between the electrode pad 7b and the probe 11, the probe 1 captured by the probe photographing television camera 16 is
By aligning the image of No. 1 with the image of the monitor cross line 18, the semiconductor element 7a on the semiconductor wafer 7 whose mounting angle was originally corrected so that it was parallel to the monitor cross line 18.
The parallel relationship between the electrode pad 7b and the probe 11 is first set, and the superposition of the image of the electrode pad 7b and the image of the probe 11 can be accomplished by a simple operation of moving the chuck top 6 in the XY direction. Further, in the above embodiment, a semiconductor test device was used in which a TV camera 16 for directly photographing the probe was provided at a position opposite to the contact portion side of the probe 11, but a reflecting mirror was provided at the opposing position, and the A similar effect can be obtained in a semiconductor testing apparatus equipped with a probe photographing television camera 16 that indirectly photographs an image of the probe 11.

As described above, the present invention places the semiconductor wafer and the probe at adjusted positions shifted from each other, and separately photographs the electrode pads formed on the semiconductor wafer and the contact portion side of the probe at this adjusted position. After displaying the images of the electrode pads and probes overlappingly on the same screen and adjusting their relative postures to match the images of the electrode pads and probes, the semiconductor wafer and the probes are placed in opposing positions, and the electrode pads and probes are bonded. This method makes it possible to easily adjust the posture of a semiconductor wafer, which has a large number of electrode pads, which would otherwise be impossible to adjust, and a corresponding number of probes. It is effective.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of a conventional semiconductor test equipment;
3 is a schematic diagram of a semiconductor testing device used in an embodiment of the present invention, and FIG. 4 is a television monitor image diagram of FIG. 3. In the figure, 7 is a semiconductor wafer, 7b is an electrode pad, 10 is a probe card, 11 is a probe,
15 is a television camera for chip photography, 16 is a television camera for probe photography, and 19 is a monitor television. Note that the same reference numerals in each figure indicate the same or equivalent parts.

Claims (1)

[Claims] 1. A method for bonding a semiconductor wafer having a large number of electrodes on one main surface and a measuring tool having a plurality of probes corresponding to the electrodes, wherein the semiconductor wafer and the measuring tool are placed in opposing positions. and at each adjustment position, the electrodes of the semiconductor wafer are photographed with a first television camera, and the contact portions are photographed with a second television camera from the tip side of each of the probes. A method for testing a semiconductor wafer, comprising: adjusting the relative posture of the semiconductor wafer and the measuring tool while displaying each of the images on a common screen in an overlapping manner.