JP2016152334A - Probe device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a probe device capable of cleaning a probe card properly without removing a probe card, in a probe device where the pressure is reduced in a space on the probe tip side of the probe card, when bringing a probe into contact with the electrode pad of a wafer.SOLUTION: When cleaning a probe card 20, a cleaning wafer CW is suction held by a wafer chuck 12, and brought into contact with the probe 21 of the probe card 20. Furthermore, the cleaning wafer CW is reciprocated in the vertical direction thus removing the deposits of the probe 21. Damage on the probe card 20 is prevented by opening a ventilation path 60, provided in the wafer chuck 12, and to the atmosphere and interconnecting with the atmosphere.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a probe apparatus, and more particularly to a probe apparatus for inspecting electrical characteristics of semiconductor elements (chips or dies) such as a plurality of integrated circuits formed on a semiconductor wafer.

  In the semiconductor manufacturing process, in the dicing process, a disk-shaped semiconductor wafer fixed to a dicing frame by a dicing apparatus is cut into a plurality of chips (dies). A wafer test process for inspecting the electrical characteristics of each chip is performed before or after the dicing process, and a probe apparatus is used in the wafer test process.

  The probe device is a device for bringing the probe of the probe card connected to the tester into contact with the electrode pad of each chip of the wafer held on the stage, and the tester supplies power and various test signals to the chip via the probe. , And a response signal output from the electrode of the chip is obtained through a probe and analyzed to check whether the chip operates normally (see, for example, Patent Document 1).

  Further, in such a probe apparatus, an improvement in throughput is strongly demanded for reducing manufacturing costs, and multi-probing is performed in which a plurality of chips (dies) are simultaneously inspected by a single contact operation. In recent years, the number of chips to be inspected at one time has been increasing, and all chips on a wafer are inspected at the same time.

  In the inspection of a semiconductor device, a burn-in test is performed in which the semiconductor device is operated for a long time under unusual environmental conditions such as high temperature or low temperature. In the burn-in test, especially when the test is performed for each chip, the test cost and time are enormous. Therefore, it is important to be able to simultaneously perform the burn-in test for all the chips on the wafer in the wafer state.

  In this way, when all the chips or a large number of chips on the wafer are simultaneously inspected, all the probes of the probe card are pressed against the electrode pads on the wafer with a substantially uniform contact pressure. In this case, the space between the probe card and the wafer is sealed by the sealing means and depressurized, and the probe of the probe card is applied to the electrode pad of the wafer by the pressure difference between the internal space sealed by the sealing means and the atmospheric pressure. A configuration for pressing is disclosed.

JP 2007-95938 A JP 2011-91262 A

  By the way, foreign matters such as aluminum scraps adhere to the tip of the probe of the probe card as the inspection is repeated. If foreign matter adheres to the tip of the probe, the contact resistance value between the probe card and the wafer increases, which adversely affects the inspection result. Therefore, it is necessary to appropriately perform cleaning for removing the deposit on the tip of the probe.

  On the other hand, since it takes time and effort to remove the probe card from the probe device and perform cleaning, it is desirable that the probe card can be cleaned while attached to the probe device.

  The present invention has been made in view of such circumstances, and in a probe device that depressurizes the space on the probe tip side of the probe card when the probe is brought into contact with the electrode pad of the wafer, the probe card is removed without removing the probe card. It is an object of the present invention to provide a probe device that can perform cleaning appropriately.

  In order to achieve the above object, a probe apparatus according to an aspect of the present invention includes a wafer supported by a wafer chuck, and a chip formed by a tester connected to the probe by contacting the chip formed on the wafer with the probe of the probe card. A probe apparatus for inspecting electrical characteristics of a probe card, comprising: a sealing means for sealing a space in which a probe tip of a probe card is disposed; and a decompression means for decompressing the space. And an air passage for communicating the space with the atmosphere, and shutter means for closing or opening the air passage.

  According to this aspect, the space at the tip of the probe sealed by the sealing means can be brought into communication with the atmosphere (external space) through the air passage by setting the shutter means to be open. Therefore, the probe deposits can be reliably removed by bringing the probe card cleaning wafer into contact with the tip of the probe and reciprocating in the perspective direction. Further, since the space at the tip of the probe is not sealed, the probe card is not loaded during the reciprocating movement of the wafer, and the probe card is not damaged.

  In the probe device according to another aspect of the present invention, the shutter means is a shutter member that is displaced by switching on and off the suction by the suction pump, and closes the air passage when the suction of the suction pump is off. It can be set as the aspect which has a shutter member which moves to a position and moves to the position which opens a ventilation path, when suction of a suction pump is ON.

  In the probe apparatus according to still another aspect of the present invention, when cleaning the probe card, the shutter means is set in a state of opening the air passage, and the cleaning wafer supported by the wafer chuck is brought into contact with the probe. It can be set as the aspect which has a control means to reciprocate in the perspective direction at a position.

  In the probe device according to still another aspect of the present invention, the air passage may have an opening communicating with a space where the tip of the probe is disposed at a position where the wafer supported by the wafer chuck is not disposed.

  According to the present invention, in a probe apparatus that depressurizes the space on the probe tip side of the probe card when the probe is brought into contact with the electrode pad of the wafer, the probe card can be appropriately cleaned without removing the probe card.

Overall configuration diagram of a wafer test system to which the present invention is applied Diagram showing the wafer chuck close to the probe card The figure explaining the structure and operation | movement for the cleaning of a probe card The perspective view which showed the shutter mechanism part from the upper surface side of a wafer chuck FIG. 5 is a cross-sectional view showing the shutter mechanism section in a cross section including the axis of the vent hole and showing a state in which the vent path is closed FIG. 5 is a cross-sectional view showing the shutter mechanism section in a cross section including the axis of the vent hole, and a view showing a state in which the vent path is opened

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic configuration diagram of a wafer test system 1 to which the present invention is applied. A wafer test system 1 shown in FIG. 1 is a prober that supports a wafer W, which is an object (inspection target) on which a large number of semiconductor chips (hereinafter simply referred to as chips) are formed, and moves and positions the inspection position. 10 (probe device), a probe card 20 having a probe 21 in contact with an electrode pad of each chip of the wafer W at the inspection position, and a test signal is given to each chip of the wafer W via the probe card 20 And a tester 30 for inspecting performance (electrical characteristics).

  The prober 10 has a wafer chuck 12 (wafer stage) that supports (holds) a wafer W as a subject by vacuum suction. On the upper surface side of the wafer chuck 12, an annular seal rubber 14 is provided as a sealing means along the peripheral edge. As will be described later, when the wafer chuck 12 (wafer W) is brought close to the probe card 20, the seal rubber 14 comes into close contact with the lower surface of the probe card 20 as shown in FIG. 2, and the inner space (probe space 50), that is, The space where the tip of the probe 21 of the probe card 20 is arranged is sealed. The sealing means for sealing the probe space 50 is not limited to the one in the present embodiment.

  The wafer chuck 12 is supported by a stage moving mechanism 16 operated by a motor so as to be movable in the X, Y, and Z axial directions orthogonal to each other and in the θ direction. The X axis and the Y axis are axes along the horizontal direction, the Z axis is an axis along the vertical direction, and the θ direction is an axis around the θ axis along the vertical direction passing through the center of the wafer chuck 12. Indicates the direction.

  The stage moving mechanism 16 is controlled by a control unit 40 that is a control unit that comprehensively controls the entire system, and is controlled by the control unit 40 with respect to the stage moving mechanism 16 based on information of a camera (not shown) and the like. The wafer W held by the wafer chuck 12 is moved and positioned. The control unit 40 is connected to an input unit (not shown) through which a user inputs predetermined information and an output unit such as a monitor that outputs predetermined information.

  Further, the prober 10 has a plate-like head stage 18 at the top, and the probe card 20 is attached to an opening 18A provided in the head stage 18.

  The probe card 20 has a large number of probes 21 arranged on the lower surface side according to the electrode arrangement of the device to be inspected, and is exchanged according to the type of device to be inspected (type of wafer W). The probe card 20 in the present embodiment is a probe card used when all the chips on the wafer W are inspected at the same time, and includes a large number of probes 21 that simultaneously contact the electrode pads of the plurality of chips. Have.

  A plurality of terminals connected to each probe 21 are provided on the upper surface side of the probe card 20, and a contact ring 31, a test head 32, and a tester body constituting the tester 30 are provided on the upper surface side of the probe card 20. The contact ring 31 and the test head 32 of 33 are arranged in a state supported by the prober 10.

  The contact ring 31 is disposed between the probe card 20 and the test head 32, and electrically connects a terminal on the upper surface side of the probe card 20 and a circuit inside the test head 32 through a number of contacts.

  The test head 32 is a circuit that is electrically connected to the wafer W via the contact ring 31 and the probe card 20, and generates a test signal to be applied to each chip of the wafer W and outputs the test signal. On the other hand, it has a circuit for fetching response signals output from each chip.

  A tester body 33 disposed on the side of the prober 10 or the like is electrically connected to the test head 32. The tester body 33 controls the test head 32 to cause the test head 32 to generate and output a test signal, take in a response signal, and the like. The tester body 33 inspects the performance of each chip (measures electrical characteristics) based on the state of the response signal to the test signal obtained via the test head 32, and determines whether each chip is good or bad (non-defective and bad). Sorting non-defective products).

  The operation of the wafer test system 1 will be described. The wafer test system 1 is comprehensively controlled by the control unit 40, and the operation of each unit corresponding to the processing content input by the user from input means (not shown) is controlled by the control unit. It is implemented by 40 controls.

  For example, when inspecting the wafer W, normally, a plurality of wafers W as a subject are accommodated in a cassette (not shown), and the wafers W are sequentially taken out from the cassette (not shown) by transfer means (not shown). It is transferred to the wafer chuck 12 and held by suction. The wafers W sequentially transferred to the wafer chuck 12 are sequentially returned to the cassette by the transfer means when the inspection is completed.

  When the wafer W is transported to the wafer chuck 12 and sucked and held, the stage moving mechanism 16 performs alignment so that the arrangement direction and position of each chip on the wafer W are in a predetermined state. Then, as shown in FIG. 2, the wafer chuck 12 moves to an inspection position where the electrode pads of the chips of the wafer W come into contact with the probes 21 of the probe card 20.

  When the wafer chuck 12 is moved to the inspection position, the seal rubber 14 of the wafer chuck 12 is in close contact with the lower surface of the probe card 20, and the probe space 50 inside the seal rubber 14 in which the probe 21 is disposed, that is, the wafer chuck 12; A probe space 50 that is a space surrounded by the probe card 20 and the seal rubber 14 is sealed. Then, the probe space 50 is depressurized by suction from a suction hole provided on the upper surface of the wafer chuck 12. As a result, the probe space 50 is set to a substantially vacuum state, and the probe card 20 is pushed to the wafer W side by the pressure difference between the atmospheric pressure on the upper surface side and the internal pressure of the probe space 50, so that all the probes 21 are substantially omitted. It is pressed against the electrode pad on the wafer W with a uniform contact pressure.

  Note that the suction hole for bringing the probe space 50 into a vacuum state may serve as a suction hole for attracting the wafer W to the wafer chuck 12 or may be other than that, or may be a wafer chuck. It may be provided in a portion other than 12.

  When this state is set, a test signal is output from the test head 32 to the wafer W according to an instruction from the tester main body 33, and a response signal is taken into the test head 32. As a result, the performance of each chip is inspected (electrical characteristic measurement), and the tester main body 33 determines the quality of each chip (selection between a good product and a defective product).

  When the inspection by the tester 30 is completed, the wafer chuck 12 and the wafer W are separated from the probe card 20 by the stage moving mechanism 16, and the wafer W is transferred from the wafer chuck 12 to the cassette by the transfer means (not shown) and stored in the cassette. .

  In addition, the wafer test system 1 performs the cleaning of the probe 21 of the probe card 20 as follows in accordance with a user instruction from the input means to the control unit 40.

  Next, cleaning of the probe 21 of the probe card 20 in the wafer test system 1 will be described.

  A foreign substance such as aluminum dust adheres to the tip of the probe 21 of the probe card 20 while the above inspection is repeated. Such adhesion of foreign substances increases the contact resistance value between the probe card 20 and the wafer W and adversely affects the inspection result.

  Therefore, it is necessary to perform cleaning at an appropriate frequency and timing to remove the deposits from the tip of the probe 21. However, removing the probe card 20 from the head stage 18 for cleaning requires troublesome work and time.

  Therefore, in the wafer test system 1 of the present embodiment, as a method of appropriately cleaning the probe card 20 without removing it from the head stage 18, a cleaning sheet is attached to a wafer made of ceramic or a mirror wafer. The attached wafer is used as a cleaning wafer for cleaning. Then, like the normal wafer W, the cleaning wafer is sucked and held by the wafer chuck 12 and brought into contact with the tip of the probe 21 of the probe card 20.

  At this time, as a special operation at the time of cleaning, as shown in FIG. 3, a position P1 where the surface CWS of the cleaning wafer CW contacts the tip of the probe 21 and pushes it up by a predetermined amount, and a position away from the tip of the probe 21 by about 300 μm The wafer chuck 12 is reciprocated up and down several times so as to reciprocate with P0. That is, the cleaning wafer CW is reciprocated a predetermined number of times in the perspective direction with respect to the probe 21.

  As a result, the tip of the probe 21 moves so as to rub against the surface CWS of the cleaning wafer CW, so that the deposit on the tip of the probe 21 is reliably removed.

  On the other hand, even during such a cleaning operation, the probe space 50 is formed by the seal rubber 14 of the wafer chuck 12, and the probe space 50 is sealed. That is, the seal rubber 14 is attracted to the probe card 20.

  For this reason, if the wafer chuck 12 is reciprocated at high speed in the vertical direction, the probe card 20 may be pulled down and damaged when the wafer chuck 12 is lowered.

  Therefore, in the wafer chuck 12 of the present embodiment, as shown in FIG. 3, an air passage 60 that allows the probe space 50 to communicate with the atmosphere (external space) is formed, and a shutter mechanism that opens and closes the air passage 60. 62 is provided on the back side of the wafer chuck 12 as shutter means. The opening of the air passage 60 communicating with the probe space 50 is provided at a position where the wafer W supported by the wafer chuck 12 is not disposed.

  In addition, switching of the opening and closing of the air passage 60 by the shutter mechanism unit 62 is performed by switching on and off the suction of the suction pump 64 that is a decompression unit (suction unit) controlled by the control unit 40.

  According to this, when the wafer W is inspected, the probe space 50 can be sealed by closing the air passage 60 by the shutter mechanism 62. On the other hand, at the time of cleaning the probe card 20 (probe 21), the probe space 50 can be brought into an unsealed state by opening the air passage 60 by the shutter mechanism 62. Therefore, the seal rubber 14 is not attracted to the probe card 20 during cleaning, and the probe card 20 is hardly damaged even when the wafer chuck 12 is reciprocated at high speed in the vertical direction (far-near direction) as a cleaning operation. The shutter mechanism 62 closes the air passage 60 when the suction by the suction pump 64 is off, and opens the air passage 60 when the suction by the suction pump 64 is on.

  Next, the configuration of the shutter mechanism unit 62 will be described. FIG. 4 is a perspective view showing the shutter mechanism 62 from the upper surface side of the wafer chuck 12.

  As shown in the figure, the wafer chuck 12 is formed in a disc shape, and a top surface of the wafer chuck 12 is a circular region including the position of the central axis (θ axis), and holds the wafer W or the cleaning wafer CW by suction. 12A (see also FIG. 3) and an annular region on the outer peripheral side of the support portion 12A, and is disposed outside the outer peripheral edge of the wafer W or the cleaning wafer CW supported by the support portion 12A. The peripheral portion 12B is formed, and the support portion 12A protrudes above the peripheral portion 12B. Further, as described above, the annular seal rubber 14 is provided on the peripheral edge portion 12B. The support portion 12A and the peripheral portion 12B are provided with a suction groove or the like having a suction hole for sucking and holding the wafer W or the cleaning wafer CW and depressurizing the probe space 50 when the wafer W is inspected.

  On the other hand, a plurality of air holes 80 forming the air passage 60 are formed inside the seal rubber 14 at the peripheral edge portion 12B where the wafer W and the cleaning wafer CW are not disposed, and the lower surface of the wafer chuck 12 through which the air holes 80 pass. The shutter mechanism 62 described above is attached to the position on the side. The vent hole 80 and the shutter mechanism 62 are provided at several locations (for example, three locations) on the peripheral edge portion 12B.

  5 and 6 are cross-sectional views showing one shutter mechanism 62 in a cross section including the axis of the air hole 80. FIG. 5 shows a state where the air passage 60 is closed, and FIG. 6 shows the air passage. 60 shows the open state.

  As shown in these drawings, the shutter mechanism 62 has a plate-like base member 90 fixed to the back surface of the wafer chuck 12, and a U-shaped flange member 92 is attached to the base member 90 with screws 94, 94. (See FIG. 4). As a result, a space portion 96 is formed between the base member 90 and the flange member 92 so as to penetrate in a radial direction (a direction perpendicular to the paper surface) when viewed from the central axis of the wafer chuck 12.

  The base member 90 is provided with a through hole 97 that communicates with the air hole 80 of the wafer chuck 12 and also communicates with the space portion 96. A vacuum pad 98 is provided at the lower end of the through hole 97.

  Pins 99 and 99 projecting from the lower surface of the base member 90 to the space portion 96 are provided on the left and right sides of the through hole 97, and the plate-like shutter member 100 having insertion holes 100A and 100A through which the pins 99 and 99 are inserted. Is disposed in the space 96. The shutter member 100 is supported by the pins 99 and 99 so as to be movable in the vertical direction in the space portion 96.

  The through hole 101 is provided in the flange member 92 so as to face the vent hole 80 of the base member 90. A vacuum pad 102 is provided at the upper end of the through hole 101. A joint 103 is provided on the lower end side of the through hole 101. The suction pump 64 shown in FIG. 3 is connected to the joint 103 via a tube.

  Further, on the upper surface side of the flange member 92, an annular recess 104 is formed in the periphery of the through hole 101, and the lower surface of the shutter member 100 is fitted into the recess 104 and slides on the inner wall surface of the recess 104. An annular convex portion 105 is provided in contact therewith. As a result, the inner space and the outer space are substantially blocked from the convex portion 105 of the shutter member 100, and the through hole 101 communicates only with the inner space of the convex portion 105 of the shutter member 100.

  Further, springs 106, 106 that urge the shutter member 100 upward are attached to the upper surface side of the flange member 92.

  According to the shutter mechanism 62 described above, when suction by the suction pump 64 connected to the joint 103 is off, the shutter member 100 is biased upward by the spring 106 as shown in FIG. The through hole 97 is closed by setting the position close to the vacuum pad 98. As a result, the vent hole 80 of the wafer chuck 12 is closed, and the probe space 50 is sealed. Therefore, when the wafer W is inspected, the suction by the suction pump 64 is set to OFF, and the probe space 50 is sealed.

  On the other hand, when the suction by the suction pump 64 is on, the shutter member 100 moves downward against the biasing force of the spring 106 by the suction force, and the vacuum pad 102 of the flange member 92 is applied to the vacuum pad 102 as shown in FIG. Move to the close contact position. As a result, the vent hole 80 of the wafer chuck 12 is opened, and the probe space 50 communicates with the atmosphere (non-sealed state). Therefore, when cleaning the probe card 20 (probe 21), the suction by the suction pump 64 is set to ON, and the probe space 50 is communicated with the atmosphere.

  As described above, in the above embodiment, the switching of the closing or opening of the air passage 60 in the shutter mechanism section 62 is not limited to the intake pump, and may be performed by any means such as an electric means.

  Further, in the above-described embodiment, the ventilation path 60 may have an opening communicating with the probe space 50 at a position where the wafer W supported by the wafer chuck 12 is not disposed.

  Moreover, in the said embodiment, this invention is applicable regardless of whether the prober 10 performs a burn-in test. Further, the present invention is not limited to the case where the probe card performs the inspection of all the chips on the wafer W at the same time, and the tip side of the probe 21 of the probe card 20 when the probe 21 is brought into contact with the electrode pad of the wafer W. This can be applied to the prober 10 that depressurizes the space (probe space 50).

  W ... wafer, CW ... cleaning wafer, 1 ... wafer test system, 10 ... prober (probe device), 12 ... wafer chuck, 14 ... seal rubber, 16 ... stage moving mechanism, 18 ... head stage, 20 ... probe card, 21 ... Probe 30. Tester 31 Contact ring 32 Test head 33 Tester body 40 Control unit 50 Probe space 60 Air passage 62 Shutter mechanism 64 Suction pump 90 Base Member, 92 ... flange member, 100 ... shutter member

Claims (4)

A probe apparatus for supporting a wafer by a wafer chuck, contacting a chip formed on the wafer with a probe of a probe card, and inspecting electrical characteristics of the chip by a tester connected to the probe, comprising: In a probe apparatus comprising: sealing means for sealing a space in which a probe tip is disposed; and decompression means for decompressing the space;
An air passage provided in the wafer chuck and communicating the space with the atmosphere;
Shutter means for closing or opening the air passage;
A probe device comprising:   The shutter means is a shutter member that is displaced by switching on and off of suction by a suction pump, and moves to a position that closes the air passage when suction of the suction pump is off. The probe apparatus according to claim 1, further comprising a shutter member that moves to a position that opens the air passage when suction is on.   When cleaning the probe card, the shutter means is set in a state in which the air passage is opened, and the cleaning wafer supported by the wafer chuck is reciprocated in the perspective direction at a position in contact with the probe. The probe device according to claim 1, further comprising a control unit for controlling the probe device.   The probe device according to claim 1, wherein the air passage has an opening communicating with the space at a position where a wafer supported by the wafer chuck is not disposed.

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