JPS60211956A - Probing machine - Google Patents

Abstract

PURPOSE:To enable to surely perform a marking on defective elements by a method wherein the titled probing machine is constituted in such a way that the marking is performed on the defective elements at a position separated from normal elements after the measurement of all elements, wafers, was completed. CONSTITUTION:Numerous wafers, which have been accommodated in a cassette 4 before being measured, are conducted to a conveying belt 5 one by one, are conveyed along an arrow in the diagram and are fed in a pre-alignment unit 6. The wafers 1, which have come being fed towards an arbitrary direction from the cassette 4, are positioned in a condition aligned in a constant direction as indicated by a one dotted chain line in the diagram in the pre-alignment unit 6. When the measurement of all of the elements, wafers, was completed, the wafers are shifted to a position E, where a marking unit 12 is standing by, in a condition fixed attractingly by a suction table 9, in brief, in the same condition as the positions and directions at a time when the wafers were measured without changing the positions and directions at a time when the wafers were measured. When a defective element, which has been memorized in advance by the instruction sent from the control part, comes right under the marking pen, the defective element is made to stop at a position located right under the marking pen. Then, the suction table 9 is made to ascend or the marking unit 12 is made to descend and a mark is put on the surface of the defective element.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a marking device for a blobbing machine that measures and inspects the electrical characteristics of semiconductor devices such as integrated circuits arranged in a grid on a wafer.

As is well known, in a blobbing machine, wafers 1 as shown in FIG. The electrical characteristics of a large number of elements 2 are measured and inspected one by one using a tester connected to a probe card that has probes in the same position and arrangement as the electrodes of the elements, and defective elements are marked with ink or the like. is marked, and defective elements are removed in a later process according to this mark. In such a blobbing machine, the conventional method for marking defective devices is that each stylus of a probe card contacts each electrode of the device, and its electrical characteristics are measured and inspected by a tester connected to the probe card. Immediately after that, a marking pen was inserted into the middle part of each stylus at that location and a mark was made.

However, as the integration and density of semiconductor devices progresses, the number of electrodes increases, and devices with more than 200 electrodes in a 10 tn m square element, for example, are manufactured. marking methods are difficult to apply. In other words, when measuring the electrical characteristics of a device with a large number of electrodes, it is necessary to use a probe card with a large number of probes in the same arrangement as the number of electrodes, but this requires a large number of probes in a small space. Since they are arranged closely together, it is difficult to insert a marking pen from the center. Furthermore, even if it is possible to insert a marking pen through such a narrow space, troublesome problems such as the marking pen touching each stylus and causing the tip of the stylus to be misaligned, or ink adhering to the stylus may occur. (1°) Also, in the case of a device to be tested, such as a 7-wire array, whose characteristics must be tested with light shining on the device,
The disadvantage was that the marking pen blocked the light, preventing light from hitting the element and making measurements impossible.

Therefore, as another marking method, we measure each element and at the same time write the address of the element [(x1, yl) in Figure 1,
(X2, y 2 ) ·--(x n, yn)] and whether or not that element is a defective element, and after completing the measurement of all the elements on the wafer, separate the wafer. One possible method is to use a dedicated marking machine to mark according to memory, but this requires that the wafer be correctly fed into the marking machine and driven in the exact order and direction as when the measurement was memorized, and that the wafer must be driven correctly before starting measurement. An essential condition is that the position of the reference element, for example (x+, y+), never deviates. Therefore, when using this marking method to process a large number of devices in a fully automated manner in succession, once a mistake occurs, subsequent markings are completely unreliable, which poses a fatal danger in practice.

It is not inconceivable that when a defective element occurs during measurement, it is possible to move the stylus and mark it.
If a defective element that requires very strict positioning is moved every time a defective element occurs, there is a risk of misalignment.
Each contact side of the probe card and the control section are connected by a large number of wires, each having the same number of probes, so it is technically very difficult to move them.

The present invention improves these points and provides a device that reliably marks using a simple mechanism. An embodiment of the present invention will be described below.

FIG. 2 is a plan view of a probing machine incorporating the marking device of the present invention. A large number of wafers to be measured are stored in a cassette 4 and are guided one by one to a conveyor belt 5 along the arrows in the figure. and transported to the pre-alignment device 6.
supplied to In the pre-alignment device 6, the wafers 1 supplied from the cassette 4 in an arbitrary direction are positioned so as to be aligned in a certain direction as shown by the dashed line in the figure. The mechanism of this pre-alignment device 6 is described in detail in Japanese Patent Publication No. 56-34092 1-Wafer Positioning Apparatus, filed by the applicant of the present application, so a description of its structure will be omitted here.

The wafer 1 positioned in the pre-alignment device 6 is sucked at the A position by the wafer suction device 7 which is movable between A and 8, and then moved to the B position. At position B, a suction table 9 that is movable up and down and rotatable on an X-Y table 8 is waiting at a position directly below the wafer suction device 7, and picks up the wafer 1 released from the wafer suction device 7. It is designed to be vacuum suctioned onto a suction table 9. In the figure, in order to clearly show the suction table 9, the first suction table 9 is not shown directly below the wafer suction device 9, but is shown moved in the Y direction.

The wafer 1 suctioned and fixed on the suction table 9 is
The wafer 1 is moved to position C by the table 8, and at this position, the suction table 9 is moved slightly in the X-Y direction or rotated slightly depending on the detection result by the optical method, and precise positioning of the wafer 1 is performed. . The wafer 1 thus positioned is moved to the measurement area D by the X-Y table 8 based on the data inputted in advance.
The probe card 10 is moved to the position D, and at this position D, a number of contacts 3'' 11 of the probe card 10, which are precisely aligned with each electrode of the element using a microscope (not shown), come into contact with each electrode of the element, for example, as indicated by the arrows in FIG. As shown in (×1, yl),
Measurement and inspection are performed in the order of (X2, y2)...(xn, yll).

At that time, if there is a defective element, the memory device of the control unit stores the address of the element, for example (x + n sy + n
) is memorized. When the measurement of all elements is completed, the wafer is moved to the waiting position E of the marking device 12 while being suctioned and fixed to the suction table 9, that is, in the same state as when it was measured without changing the position or direction. Then, the defective element previously marked or marked by a command from the control unit stops directly under the marking pen, and as the suction table 9 rises or the marking pen 12 descends, the surface of the element is removed. mark.

For example, as shown in FIG. 3, the marking device 12 has an ink pot 14 housed in one end of an arm 13 fixed to the base of a blobbing machine, and a marking pen 15 held at the tip of the arm 13. What is available is used. The device shown at 16 in FIG. 3 is a mark sensor, that is, a detector that detects whether or not the marking device 12 has reliably marked a defective element. It is possible to detect whether a mark has been added or not. One mark sensor may be provided close to the marking pen 15 as shown in 16 to detect the presence or absence of a mark immediately after it is attached, or
In addition, as shown in 17.18, two pens are provided before and after the marking pen 14, separated by one or more pens, to detect the presence or absence of a mark when an element with a mark is sent under it. You may also do so. In this case, the reason why two mark sensors are provided at the front and rear is that the wafer is sometimes fed from left to right and sometimes from right to left, as shown by the arrows in FIG. If the mark sensor detects that the defective element is not marked, it may be due to some reason, such as the ink bottle 14 running out of ink or the marking pen 14 not making enough contact with the element. Since it is assumed that a trouble has occurred, by stopping the operation of the device and resolving the trouble, it is possible to prevent defective elements from being mixed with non-defective products in the subsequent process.

The wafer 1 with all the defective elements marked in this manner is moved to the F position while being suctioned and fixed on the suction table 9. A wafer suction device 19 that can move between F-0 is waiting at position F, and picks up the wafer 1 that has been subjected to measurement and inspection, transports it to position G, and releases it. The released wafer 1 is conveyed by the conveyor belt 20 along the arrow in the figure and is housed in the wafer storage cassette 21 to complete the measurement.

As described in detail above, according to the present invention, the defective elements are marked at a different position after the measurement of all the elements on the wafer is completed. Alternatively, it solves the drawbacks of marking methods using a special machine other than a blobbing machine, making it possible to mark reliably and prevent defective elements from being mixed into non-defective products in the subsequent process due to marking mistakes. This makes it possible to contribute to improving the yield (rate of non-defective finished products). Furthermore, the present invention utilizes the drive mechanism of the wafer in the X and Y directions that is originally included in a normal blobbing machine, and by adding a small number of frame parts, it is possible to perform error-free marking, which was previously thought to be difficult. It is possible to add (11) the confirmation function, and it brings extremely large practical effects in terms of reliability and economy.

[Brief explanation of drawings]

FIG. 1 is a plan view of the wafer, FIG. 2 is a plan view of the present invention, and FIG. 3 is a view taken along the line ■-■ of the t52 diagram. 1: Wafer 2: Semiconductor probe 3: Defective element mark 8: X-Y table 9: Suction table 10 Nibrobe card 11: Stylus 12: Marking device 16.17.18: Mark sensor patent applicant Tokyo Seimitsu Co., Ltd.

Claims (2)

[Claims] (1) Equipped with a table on which a wafer is placed, an X-Y table drive mechanism that transports the table to a measurement position and enables step feeding in the X and Y directions, and a control unit thereof,
In a blobbing machine that sequentially measures the electrical characteristics of semiconductor devices arranged in a grid on a wafer through a stylus that contacts each electrode of the device, a marking position is set up separately from the measurement position, and after the measurement is completed, A blobbing machine, characterized in that it is provided with a marking device that moves the wafer using the drive control mechanism and marks defective elements based on the pass/fail determination results stored at the time of measurement. (2) The blobbing machine according to claim 111(1), characterized in that a sensor for confirming a defective element mark is provided at the marking position.