Prober

Abstract

To provide a prober capable of maintaining parallelism between a probe card and a wafer, and performing a wafer level inspection with high accuracy.SOLUTION: A prober includes: a wafer chuck 50; a probe card 56; decompression means for decompressing a sealed space S formed between the wafer chuck 50 and the probe card 56; a pogo frame 58 that is disposed above the probe card 56, is electrically connected to the probe card 56, and is supported by the head stage 52; and a test head 54 that is placed on the pogo frame 58 while its outer edge part is uniformly supported and its own weight is reduced. The test head 54, the pogo frame 58, and the probe card 56 are integrated by fixing the pogo frame 58 to the head stage 52, the probe card 56 to the pogo frame 58, and the test head 54 to the pogo frame 58.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a prober for inspecting the electrical characteristics of a plurality of semiconductor devices (chips) formed on a semiconductor wafer, and more particularly to a prober having a plurality of measurement units stacked in multiple stages.

Background Art

[0002] The semiconductor manufacturing process has a large number of steps, and various inspections are performed in various manufacturing steps to ensure quality and improve yield. For example, at the stage where a plurality of chips of semiconductor devices are formed on a semiconductor wafer, the electrode pads of the semiconductor devices of each chip are connected to a test head, a power supply and test signals are supplied from the test head, and the signals output from the semiconductor devices are measured by the test head to electrically inspect whether they operate normally. Wafer-level inspection is being carried out.

[0003] After wafer-level inspection, the wafer is attached to a frame and cut into individual chips by a dicing saw. Only the chips that have been confirmed to operate normally among the cut chips are packaged in the next assembly process, and the malfunctioning chips are removed from the assembly process. Furthermore, the packaged final product is subjected to a shipping inspection.

[0004] Wafer-level inspection is performed using a prober that brings probes into contact with the electrode pads of each chip on the wafer (see, for example, Patent Document 1). The probes are electrically connected to the terminals of the test head, and a power supply and test signals are supplied from the test head to each chip via the probes, and the output signals from each chip are detected by the test head to measure whether they operate normally.

[0005] In semiconductor manufacturing processes, in order to reduce manufacturing costs, wafers are being made larger and further miniaturized (integrated), and the number of chips formed on a single wafer has become extremely large. Along with this, the time required to inspect a single wafer with a probe has also become longer, and an improvement in throughput is demanded. Therefore, in order to improve throughput, multiprobing is carried out, in which a large number of probes are provided so that multiple chips can be inspected simultaneously. In recent years, the number of chips inspected simultaneously has been increasing steadily, and attempts have even been made to inspect all the chips on a wafer simultaneously. For this reason, the allowable error in alignment for bringing the electrode pads into contact with the probes has become smaller, and it is required to increase the positional accuracy of movement in the probe.

[0006] On the other hand, as the simplest method of increasing throughput, it is conceivable to increase the number of probes. However, increasing the number of probes causes a problem that the installation area of the probes in the manufacturing line also increases. In addition, increasing the number of probes will also increase the equipment cost accordingly. Therefore, it is required to increase the throughput while suppressing an increase in the installation area and an increase in the equipment cost.

[0007] In response to such problems, the applicant of the present application has proposed a probe having a plurality of measurement units stacked in multiple stages (see Patent Document 2). In this probe, since the plurality of measurement units have a stacked structure (multi-stage structure) stacked in multiple stages, wafer-level inspection can be performed for each measurement unit, and the throughput can be improved while suppressing an increase in the installation area and an increase in the equipment cost.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0009] By the way, in the prober disclosed in Patent Document 1, the test head is held by a holder, rotated from a retracted position away from the top plate (head stage) of the prober body to a horizontal position, and then the test head is delivered to an elevating support mechanism provided in the prober body. The test head is lowered by this elevating support mechanism to attach the test head to the prober body.

[0010] A probe card is attached to this head stage. In order to accurately perform inspection by bringing each probe of the probe card into contact with the electrode pads of each chip of the wafer, it is necessary to ensure the parallelism between the probe card and the wafer. Particularly in the case of the so-called batch contact method of simultaneously inspecting all chips of a wafer, higher accuracy of the parallelism between the probe card and the wafer is required to uniformly bring each probe of the probe card into contact with the electrode pads of each chip of the wafer.

[0011] However, since the prober proposed by the applicant of the present application has a plurality of measurement units stacked in multiple stages, it is difficult to realize the configuration as disclosed in Patent Document 1 in terms of layout.

[0012] For example, although it is conceivable to directly mount the test head on the head stage, if the load of the test head applied to the head stage exceeds the allowable range, the deformation of the head stage becomes large, and the parallelism between the probe card and the wafer cannot be maintained. As a result, it becomes a factor for reducing the measurement accuracy of wafer-level inspection.

[0013] In addition, in the prober proposed by the applicant of the present application, the internal space formed between the probe card and the wafer chuck is depressurized to draw the wafer chuck toward the probe card. However, due to the influence of uneven load such as the components of the wafer chuck, the wafer chuck may tilt or shift in position. In this case, the parallelism between the probe card and the wafer deteriorates, and each probe of the probe card cannot be uniformly brought into contact with the electrode pads of each chip of the wafer, resulting in a decrease in the measurement accuracy of the wafer-level inspection.

[0014] The present invention has been made in view of such circumstances, and an object thereof is to provide a prober capable of maintaining the parallelism between a probe card and a wafer and performing wafer-level inspection with high accuracy.

Means for Solving the Problems

[0015] To achieve the above object, a prober according to the present invention includes a wafer chuck for holding a wafer, a probe card having a plurality of probes on a surface facing the wafer on the wafer chuck, a sealing means for sealing between the wafer chuck and the probe card to form a sealed space, a decompression means for decompressing the sealed space to draw the wafer chuck upward with reference to the probe card, a pogo frame disposed above the probe card and electrically connected to the probe card and supported by the apparatus, and a test head placed on the pogo frame while being evenly supported at the outer edge portion to reduce its own weight.

Effects of the Invention

[0016] According to the present invention, the parallelism between the probe card and the wafer can be maintained, and wafer-level inspection can be performed with high accuracy.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0018] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0019] FIGS. 1 and 2 are an external view and a plan view showing the overall configuration of a probe according to an embodiment of the present invention.

[0020] As shown in FIGS. 1 and 2, the probe 10 of the present embodiment includes a loader unit 14 that supplies and recovers a wafer W (see FIG. 4) to be inspected, and a measurement unit 12 that is arranged adjacent to the loader unit 14 and has a plurality of measurement units 16. The measurement unit 12 has a plurality of measurement units 16. When the wafer W is supplied from the loader unit 14 to each measurement unit 16, each measurement unit 16 inspects the electrical characteristics of each chip of the wafer W (wafer-level inspection). Then, the wafer W inspected by each measurement unit 16 is recovered by the loader unit 14. The probe 10 also includes an operation panel 21, a control device (not shown) that controls each part, and the like.

[0021] The loader unit 14 includes a load port 18 on which the wafer cassette 20 is placed, and a transfer unit 22 that transfers the wafer W between each measurement unit 16 of the measurement unit 12 and the wafer cassette 20. The transfer unit 22 is provided with a transfer unit drive mechanism (not shown), and is configured to be movable in the X and Z directions, and is also configured to be rotatable in the θ direction (around the Z direction). Further, the transfer unit 22 includes a transfer arm 24 that is configured to be telescopically extendable and retractable by the above-described transfer unit drive mechanism. An adsorption pad (not shown) is provided on the upper surface portion of the transfer arm 24, and the transfer arm 24 holds the wafer W by vacuum-adsorbing the back surface of the wafer W with this adsorption pad. Thereby, the wafer W in the wafer cassette 20 is taken out by the transfer arm 24 of the transfer unit 22 and is transferred to each measurement unit 16 of the measurement unit 12 while being held on its upper surface. Also, the inspected wafer W after the inspection is returned from each measurement unit 16 to the wafer cassette 20 through the reverse path.

[0022] FIG. 3 is a diagram showing the configuration of the measurement unit 12.

[0023] As shown in FIG. 3, the measurement unit 12 has a stacked structure (multi-stage structure) in which a plurality of measurement units 16 are stacked in multiple stages, and each measurement unit 16 is two-dimensionally arranged along the X and Z directions. In the present embodiment, as an example, four measurement units 16 in the X direction are stacked in three stages in the Z direction. Note that each measurement unit 16 has the same configuration, and as will be described in detail later, is configured to include a wafer chuck 50, a probe card 56, and the like.

[0024] The measurement unit 12 includes a housing (not shown) having a lattice shape formed by combining a plurality of frames in a lattice pattern. This housing is formed by combining a plurality of frames extending in the X, Y, and Z directions in a lattice pattern, and the components of the measurement unit 16 are arranged in each space portion surrounded by these frames.

[0025] Next, the configuration of the measurement unit 16 will be described. FIG. 4 is a schematic diagram showing the configuration of the measurement unit 16.

[0026] As shown in FIG. 4, the measurement unit 16 includes a wafer chuck 50, a head stage 52, a test head 54, a probe card 56, and a pogo frame 58.

[0027] The test head 54 is supported above the head stage 52 by a test head holding unit 80, the details of which will be described later. The test head 54 is electrically connected to the probes 66 of the probe card 56, supplies power and test signals to each chip for electrical inspection, and detects the output signals from each chip to measure whether it operates normally.

[0028] The head stage 52 is supported by a frame member 34 that forms part of the housing, and has a pogo frame mounting portion 53 that is a circular opening corresponding to the planar shape of the pogo frame 58. The pogo frame mounting portion 53 has positioning pins (not shown), and the pogo frame 58 is fixed to the pogo frame mounting portion 53 in a state positioned by the positioning pins. In the present embodiment, as an example, the pogo frame mounting portion 53 has a suction surface for sucking and fixing the pogo frame 58, and the pogo frame 58 is sucked and fixed to the suction surface of the pogo frame mounting portion 53 by suction means (not shown). Thereby, the pogo frame 58 is reliably fixed to the head stage 52. Note that the fixing method of the pogo frame 58 is not limited to the present embodiment, and for example, mechanical fixing means such as screws may be used.

[0029] The pogo frame 58 includes a number of pogo pins (not shown) that electrically connect each terminal formed on the lower surface of the test head 54 (the surface facing the pogo frame 58) and each terminal formed on the upper surface of the probe card 56 (the surface facing the pogo frame 58). Further, ring-shaped seal members (not shown) are formed on the outer peripheral portions of the upper surface (the surface facing the test head 54) and the lower surface (the surface facing the probe card 56) of the pogo frame 58, respectively. Then, by reducing the pressure in the space surrounded by the test head 54, the pogo frame 58, and the upper surface side seal member, and the space surrounded by the probe card 56, the pogo frame 58, and the lower surface side seal member by suction means (not shown), the test head 54, the pogo frame 58, and the probe card 56 are integrated. Note that the upper surface and the lower surface of the pogo frame 58 are examples of a first adsorption fixing portion and a second adsorption fixing portion, respectively.

[0030] The probe card 56 is provided with a plurality of probes 66 such as cantilevers and spring pins, which are arranged corresponding to the electrodes of each chip of the wafer W to be inspected. Each probe 66 is formed to protrude downward from the lower surface of the probe card 56 (the surface facing the wafer chuck 50), and is electrically connected to each terminal provided on the upper surface of the probe card 56 (the surface facing the pogo frame 58). Therefore, when the test head 54, the pogo frame 58, and the probe card 56 are integrated, each probe 66 is electrically connected to each terminal of the test head 54 via the pogo frame 58. Note that the probe card 56 in this example includes a number of probes 66 corresponding to the electrodes of all the chips of the wafer W to be inspected, and in each measurement unit 16, simultaneous inspection of all the chips on the wafer W held by the wafer chuck 50 is performed.

[0031] The wafer chuck 50 adsorbs and fixes the wafer W by vacuum adsorption or the like. The wafer chuck 50 is detachably supported and fixed to an alignment device 70 described later. The alignment device 70 performs relative alignment between the wafer W held by the wafer chuck 50 and the probe card 56 by moving the wafer chuck 50 in the X, Y, Z, and θ directions.

[0032] Also, a ring-shaped seal member (hereinafter referred to as "chuck seal rubber") 64 having elasticity is provided on the outer peripheral portion of the upper surface (wafer placement surface) of the wafer chuck 50. When the wafer chuck 50 is moved (raised) toward the probe card 56 by the Z-axis movement / rotation unit 72 described later, the chuck seal rubber 64 contacts the lower surface of the head stage 52, thereby forming an internal space S (see FIG. 5) surrounded by the wafer chuck 50, the probe card 56 (head stage 52), and the chuck seal rubber 64. Then, by evacuating the aforementioned internal space S by a suction means (pressure reducing means) (not shown), the wafer chuck 50 is attracted toward the probe card 56. As a result, each probe 66 of the probe card 56 comes into contact with the electrode pads of each chip of the wafer W, enabling the inspection to start. Note that the chuck seal rubber 64 is an example of an annular seal member.

[0033] Inside the wafer chuck 50, a heating / cooling mechanism (not shown) as a heating / cooling source is provided so that electrical characteristic inspection can be performed on the chip in a high-temperature state (for example, up to 150°C) or a low-temperature state (for example, down to -40°C). As the heating / cooling mechanism, a known appropriate heater / cooler can be adopted. For example, a double-layer structure having a heating layer of a surface heater and a cooling layer provided with a passage for a cooling fluid, or a heating / cooling device having a single-layer structure in which a cooling pipe with a heating heater wound around a heat conductor is embedded can be considered. Also, instead of electric heating, a device that circulates a heat fluid may be used, or a Peltier element may be used.

[0034] The alignment device 70 includes an alignment device 70 that detachably supports the wafer chuck 50 by vacuum suction or the like. As described above, the alignment device 70 performs relative alignment between the wafer W held by the wafer chuck 50 and the probe card 56. The alignment device 70 detachably supports and fixes the wafer chuck 50, moves the wafer chuck 50 in the Z-axis direction, and rotates it in the θ direction around the Z-axis as the rotation center. It also includes a Z-axis movement / rotation unit 72, an X-axis moving stage 74 that supports the Z-axis movement / rotation unit 72 and moves in the X-axis direction, and a Y-axis moving stage 76 that supports the X-axis moving stage 74 and moves in the Y-axis direction.

[0035] The Z-axis movement / rotation unit 72, the X-axis moving stage 74, and the Y-axis moving stage 76 are each configured to be movable or rotatable in a predetermined direction with respect to the wafer chuck 50 by a mechanical drive mechanism including at least a motor. As the mechanical drive mechanism, for example, it is configured by a ball screw drive mechanism that combines a servo motor and a ball screw. Also, it is not limited to the ball screw drive mechanism and may be configured by a linear motor drive mechanism, a belt drive mechanism, or the like. Note that the Z-axis movement / rotation unit 72 is an example of mechanical lifting means.

[0036] The alignment device 70 is provided for each stage (see FIG. 3) and is configured to be movable relative to each other among a plurality of measurement units 16 arranged in each stage by an alignment device drive mechanism (not shown). That is, the alignment device 70 is shared among a plurality (four in this example) of measurement units 16 arranged in the same stage and moves among the plurality of measurement units 16 arranged in the same stage. The alignment device 70 that has moved to each measurement unit 16 is fixed in a state of being positioned at a predetermined position by a positioning and fixing device (not shown), and the wafer chuck 50 is moved in the X, Y, Z, and θ directions by the above-described alignment device drive mechanism to perform relative alignment between the wafer W held by the wafer chuck 50 and the probe card 56. Although not shown in the figure, the alignment device 70 includes a needle position detection camera and a wafer alignment camera in order to detect the relative positional relationship between the electrodes of the chips of the wafer W held by the wafer chuck 50 and the probes 66.

[0037] In this embodiment, the alignment device 70 (Z-axis movement / rotation unit 72) has a suction port (an example of a wafer chuck fixing unit) on its upper surface, and adsorbs and fixes the wafer chuck 50 by a suction means (not shown). However, as a fixing method of the wafer chuck 50, various well-known methods can be adopted as long as the wafer chuck 50 can be detachably fixed, and a mechanical method using a clamp or the like may be used. Further, it is preferable that the alignment device 70 is provided with a positioning member (not shown) so that the relative positional relationship with the wafer chuck 50 is always constant.

[0038] In this embodiment, in addition to the above-described configuration, further, when the wafer chuck 50 is attracted toward the probe card 56 by depressurizing the internal space S, as a configuration for preventing the positional deviation and inclination of the wafer chuck 50 in the X and Y directions (horizontal directions), a chuck guide mechanism 90 for guiding the wafer chuck 50 in the Z direction (vertical direction) is provided. The chuck guide mechanism 90 is an example of a guiding means.

[0039] The chuck guide mechanism 90 is provided in parallel in the circumferential direction of the peripheral edge of the wafer chuck 50, specifically, the outer peripheral portion of the chuck guide holding portion 94 integrated with the wafer chuck 50. The chuck guide mechanism 90 functions as a guide mechanism that adsorbs and fixes the chuck guide 98 described later to the head stage 52 by vacuum suction or the like before the operation of attracting the wafer chuck 50 toward the probe card 56 by depressurizing the internal space S, thereby restricting the horizontal movement of the wafer chuck 50 and moving it parallel in the Z direction. Therefore, at least three chuck guide mechanisms 90 are provided at positions different from each other in the horizontal directions (X and Y directions) orthogonal to the moving direction (Z direction) of the wafer chuck 50 (chuck guide holding portion 94). In this example, although not shown in the figure, three chuck guide mechanisms 90 are provided at equal intervals (every 120 degrees) along the circumferential direction in the chuck guide holding portion 94 (only one is shown in FIG. 4).

[0040] Here, the configuration of the chuck guide mechanism 90 will be described in detail.

[0041] The chuck guide mechanism 90 includes a bearing portion 96 formed in a chuck guide holding portion 94, and a chuck guide (guide shaft portion) 98 configured to be movable in the Z direction (vertical direction) while its movement in the X and Y directions (horizontal directions) is restricted by the bearing portion 96. The bearing portion 96 is composed of, for example, a ball bearing or the like.

[0042] The chuck guide 98 is rotatably supported by the bearing portion 96, and a fixing portion 100 for detachably fixing the chuck guide 98 to the head stage 52 is provided on its upper portion. A ring-shaped seal member (hereinafter referred to as "chuck guide seal rubber") 102 is provided on the upper surface of the fixing portion 100, and a suction port (not shown) connected to a suction means (not shown) and a clearance holding member 104 for keeping the distance (gap) between the fixing portion 100 and the head stage 52 constant are provided inside the chuck guide seal rubber 102. The shape of the clearance holding member 104 is not particularly limited as long as it can maintain a constant gap between the fixing portion 100 and the head stage 52.

[0043] With such a configuration, the wafer chuck 50 is moved to a predetermined height by the Z-axis movement / rotation unit 72. After the chuck guide seal rubber 102 is brought into contact with the head stage 52, when the internal space Q formed between the chuck guide seal rubber 102, the head stage 52, and the fixing portion 100 is depressurized by a suction means (not shown), the fixing portion 100 of the chuck guide 98 is adsorbed and fixed to the head stage 52. At this time, since a constant gap is secured between the head stage 52 by the clearance holding member 104 described above, excessive adsorption by the fixing portion 100 of the chuck guide 98 is suppressed, and the inclination of the chuck guide 98 fixed to the head stage 52 can be prevented. Then, when the wafer chuck 50 is attracted toward the probe card 56 by depressurizing the internal space S, the wafer chuck 50 can move in the Z direction while its movement in the X and Y directions is restricted by the chuck guide 98 fixed to the head stage 52. As a result, it is possible to prevent inclination and displacement due to uneven load by the components of the wafer chuck 50, and it becomes possible to stably perform the transfer operation of the wafer chuck 50 while maintaining parallelism, and it becomes possible to realize good contact between the electrode pads on the wafer W and the probes 66.

[0044] In addition, in the present embodiment, a height detection sensor 92 for detecting the relative distance between the head stage 52 and the wafer chuck 50 is provided on the head stage 52. This height detection sensor 92 is provided to monitor the height position and inclination of the wafer chuck 50 when the wafer chuck 50 is attracted toward the probe card 56 by decompression of the internal space S. Therefore, at least three height detection sensors 92 are provided at different positions from each other in the X and Y directions (horizontal directions) orthogonal to the Z direction (vertical direction), which is the moving direction of the wafer chuck 50, on the head stage 52 (only one is shown in FIG. 4). According to this configuration, it is possible to monitor the height position and inclination of the wafer chuck 50 from the detection results of the respective height detection sensors 92. Therefore, when the wafer chuck 50 is attracted toward the probe card 56 by decompression of the internal space S, it is possible to monitor the crushing amount (overdrive amount) of the probe 66, the inclination of the wafer chuck 50, the state change during measurement, etc., and it is possible to accurately determine whether the measurement is being performed correctly.

[0045] Next, with reference to FIGS. 4 to 7, the configuration of the test head holding portion 80 will be described in detail. Note that FIG. 6 is a plan view showing the planar arrangement relationship of the test head holding portion 80, and FIG. 7 is a side view of the test head holding portion 80 as viewed from the side. In FIG. 6, for convenience of explanation, the test head 54 is illustrated by a dashed line.

[0046] As shown in FIGS. 4 to 7, the test head holding portion 80 is provided intervening between a receiving portion 54a provided on the upper surface side of the test head 54 and the frame member 34. The lower end of the test head holding portion 80 is installed on the frame member 34, and its upper end supports the receiving portion 54a of the test head 54. That is, the test head 54 is supported by the frame member 34 by the test head holding portion 80, and the load of the test head 54 is not directly applied to the head stage 52, so that the parallelism between the probe card 56 and the wafer W can be maintained, and wafer-level inspection can be performed with high accuracy. The specific configuration of the test head holding portion 80 is as follows.

[0047] The test head holding unit 80 includes a lifting mechanism 82 that raises and lowers the test head 54 in the Z direction, a guide unit 84 that guides the movement of the test head 54 in the Z direction when the lifting mechanism 82 raises and lowers the test head 54, and a buffer unit 86 that maintains constant the distance (clearance) and parallelism between the test head 54 and the probe card 56.

[0048] The lifting mechanism 82 is configured, for example, with an air cylinder or an electric mechanism, and lifts and lowers the test head 54 in the Z direction. The lower end of this lifting mechanism 82 is fixed to the frame member 34, and the upper end thereof supports the receiving portion 54a of the test head 54. The number and arrangement of the lifting mechanisms 82 are not particularly limited as long as they can lift and lower the test head 54 in the Z direction. In this embodiment, as an example, two lifting mechanisms 82A and 82B are provided corresponding to the receiving portion 54a of the test head 54. This distributes the load of the test head 54 to each of the lifting mechanisms 82A and 82B, allowing the test head 54 to be lifted and lowered stably and reliably in the Z direction. The receiving portion 54a of the test head 54 has a flange surface (protruding surface) protruding laterally (in the X direction) from the upper end of the test head 54, and this flange surface is supported by the upper end of the lifting mechanism 82.

[0049] The guide portion 84 has a regulating surface 85 facing the side surface of the test head 54 (a surface perpendicular to the X direction), and the side surface of the receiving portion 54a of the test head 54 abuts against this regulating surface 85 to guide the movement of the test head 54 in the Z direction while restricting the movement of the test head 54 in the horizontal directions (X and Y directions). The number and arrangement of the guide portions 84 are not particularly limited as long as they can regulate the position and orientation of the test head 54. In the present embodiment, as an example, four guide portions 84A to 84D are provided so as to sandwich the side surfaces of the receiving portions 54a on both sides of the test head 54. Specifically, the guide portions 84A and 84B are arranged on both sides sandwiching the elevating mechanism 82A, and the guide portions 84C and 84D are arranged on both sides sandwiching the elevating mechanism 82B. In other words, the guide portion 84A and the guide portion 84C, and the guide portion 84B and the guide portion 84D are arranged at positions facing each other with the test head 54 therebetween. Thereby, when the test head 54 is moved up and down in the vertical direction, the vertical movement of the test head 54 is guided while the horizontal movement (position and orientation) of the test head 54 is restricted by each guide portion 84 (84A to 84D).

[0050] The buffer portion 86 has a spring member 88 interposed between a spring receiving portion 87 fixed to the frame member 34 and the receiving portion 54a of the test head 54. This spring member 88 has a biasing force for biasing the test head 54 upward (that is, on the side opposite to the pogo frame 58), and has a function of properly maintaining the distance and parallelism between the test head 54 and the pogo frame 58. In the present embodiment, as an example, it has a plurality of buffer portions 86A to 86D, and each of the buffer portions 86A to 86D supports the end portion of the receiving portion 54a of the test head 54. That is, each of the buffer portions 86A to 86D is arranged at a position equidistant from the center of gravity of the test head 54. Thereby, the load of the test head 54 is evenly distributed, and it is possible to properly maintain the horizontal posture of the test head 54.

[0051] With the above configuration, the test head 54 is guided while the movement in the X and Y directions (horizontal directions) is restricted by the guide portions 84 (84A to 84D), and moves in the Z direction (vertical direction) by the elevating mechanism 82 (82A, 82B). As a result, the test head 54 can move stably between the retracted position and the mounted position.

[0052] Also, when the test head 54 is moved to the mounted position by the elevating mechanism 82 (82A, 82B), the spring members 88 of the buffer portions 86 (86A to 86D) can appropriately maintain the distance and parallelism between the test head 54 and the pogo frame 58. Therefore, once the parallel adjustment between the test head 54 and the pogo frame 58 is performed at the initial setting, the parallelism is always maintained even when the test head 54 is raised and lowered, so that it is not necessary to readjust the parallelism of the test head 54, and the time and labor required for the adjustment can be reduced.

[0053] Next, the inspection method using the probe 10 of the present embodiment will be described.

[0054] In the inspection method using the probe 10 of the present embodiment, as a prior preparation, an integration process for integrating the test head 54, the pogo frame 58, and the probe card 56 is performed. Specifically, the integration process is performed as follows.

[0055] In the integration process, first, after the pogo frame 58 is adsorbed and fixed to the head stage 52 by vacuum adsorption or the like, the probe card 56 is adsorbed and fixed to the pogo frame 58 by vacuum adsorption or the like. Subsequently, while restricting the movement of the test head 54 in the X and Y directions (horizontal directions) by the guide portion 84, the test head 54 is moved to the mounting position by the elevating mechanism 82. At this time, the test head 54 is not in contact with the pogo frame 58, and the distance (clearance) and parallelism between the test head 54 and the pogo frame 58 are appropriately maintained by the spring members 88 of the buffer portions 86 (86A to 86D). Then, the test head 54 is adsorbed and fixed to the pogo frame 58 by vacuum adsorption or the like. As a result, the test head 54, the pogo frame 58, and the probe card 56 are in an integrated state.

[0056] After the integration process is performed in this way, the following operations are carried out in the prober 10.

[0057] First, in the loader unit 14, the wafer W in the wafer cassette 20 is taken out by the transfer arm 24 of the transfer unit 22 and transferred to each measurement unit 16 of the measurement unit 12 while being held on the upper surface of the transfer arm 24.

[0058] On the other hand, in the measurement unit 12, the alignment device 70 provided for each stage moves to a predetermined measurement unit 16, and the wafer chuck 50 is positioned on the upper surface of the alignment device 70 and fixed by adsorption.

[0059] Subsequently, the alignment device 70 moves the wafer chuck 50 to a predetermined delivery position. And when the wafer W is delivered from the transfer unit 22 of the loader unit 14, the wafer W is held on the upper surface of the wafer chuck 50.

[0060] Next, the alignment device 70 moves the wafer chuck 50 holding the wafer W to a predetermined alignment position, and detects the relative positional relationship between the electrodes of the chips of the wafer W held by the wafer chuck 50 and the probes 66 using a needle position detection camera (not shown) and a wafer alignment camera. Based on the detected positional relationship, the wafer chuck 50 is moved in the X, Y, Z, and θ directions to perform relative alignment between the wafer W held by the wafer chuck 50 and the probe card 56.

[0061] After this alignment is performed, the alignment device 70 moves the wafer chuck 50 to a predetermined measurement position (the position facing the probe card 56), and raises the wafer chuck 50 by the Z-axis movement / rotation unit 72 of the alignment device 70 until the chuck guide seal rubber 102 contacts the head stage 52. At this time, as the height of the wafer chuck 50 after the raising (the upper surface height of the wafer chuck 50), a mode where it is higher than the tip position (contact position) of the probe 66 is preferable. In this mode, each probe 66 of the probe card 56 contacts the electrode pads of each chip of the wafer W in an over-drive state, so the tip of the probe 66 sinks into the surface of the electrode pad, forming stitch marks on the surface of each electrode pad. Thus, the oxide film formed on the electrode pad can be removed by the contact of the probe 66, and the positional deviation (lateral deviation) of the probe 66 in the X and Y directions (horizontal directions) can be prevented against the disturbance (vibration) generated when the wafer chuck 50 is transferred from the alignment device 70 to the head stage 52 (probe card 56 side). When the influence of the oxide film formed on the electrode pad is small, the height of the wafer chuck 50 after the raising may be a position lower (clearance height) than the tip position (contact position) of the probe 66.

[0062] Next, the chuck guide 98 of the chuck guide mechanism 90 is fixed to the head stage 52. Specifically, after the chuck guide seal rubber 102 contacts the head stage 52 as described above, the internal space Q formed inside the chuck guide seal rubber 102, the head stage 52, and the fixing portion 100 is depressurized by a suction means (pressure reducing means) (not shown), thereby adsorbing and fixing the fixing portion 100 to the head stage 52.

[0063] Next, after releasing the adsorption and fixing of the wafer chuck 50 by the Z-axis movement / rotation unit 72, while detecting the height position of the wafer chuck 50 by a plurality of height detection sensors 92 provided on the head stage 52, the internal space S surrounded by the head stage 52 (probe card 56), the wafer chuck 50, and the chuck seal rubber 64 is depressurized by a suction means (not shown). At this time, since the chuck guide 98 (fixing portion 100) of the chuck guide mechanism 90 is adsorbed and fixed to the head stage 52 as described above, the movement of the wafer chuck 50 in the X and Y directions (horizontal directions) is restricted by the chuck guide 98, and the movement in the Z direction (vertical direction) is guided. As a result, the wafer chuck 50 is attracted toward the probe card 56 without tilting or displacement, and the probe card 56 and the wafer chuck 50 are in close contact with each other, and each probe 66 of the probe card 56 contacts the electrode pads of each chip of the wafer W with a uniform contact pressure.

[0064] Also, in the present embodiment, based on the detection results of each height detection sensor 92, the height position and inclination of the wafer chuck 50 are obtained, and a process of determining whether or not these values are within an appropriate range is performed. Note that this determination process is performed by the control device described above. Thereby, when the wafer chuck 50 is attracted toward the probe card 56 by depressurizing the internal space S, it is possible to accurately confirm the amount of crushing (overdrive amount) of the probe 66, monitor the inclination of the wafer chuck 50, changes in the state during measurement, etc., and accurately determine whether or not the measurement is being performed correctly.

[0065] As described above, when the wafer chuck 50 is transferred from the alignment device 70 (Z-axis movement / rotation unit 72) to the head stage 52 (probe card 56 side), as shown in FIG. 5, the test head 54, the pogo frame 58, the probe card 56, and the wafer chuck 50 are integrated, and each probe 66 of the probe card 56 contacts the electrode pads of each chip of the wafer W with a uniform contact pressure. As a result, the wafer-level inspection can be started. Thereafter, power and test signals are supplied from the test head 54 to each chip of the wafer W via each probe 66, and signals output from each chip are detected to perform an electrical operation inspection.

[0066] Note that after the wafer chuck 50 is transferred from the alignment device 70 (Z-axis movement / rotation unit 72) to the head stage 52 (probe card 56 side), the alignment device 70 moves to another measurement unit 16, and a contact operation is performed in the same procedure in the measurement unit 16, and wafer-level inspections are sequentially performed.

[0067] As described above, according to the present embodiment, by interposing the test head holding unit 80 between the receiving unit 54a of the test head 54 and the frame member 34, the test head 54 is configured to be supported by the frame member 34. Therefore, the load on the test head 54 is not directly applied to the head stage 52, and deformation of the pogo frame 58 is prevented, so that it is possible to easily ensure the parallelism between the wafer W and the probe card 56, and the accuracy of the wafer-level inspection can be improved.

[0068] In particular, according to the present embodiment, since the test head holding unit 80 includes the elevating mechanism 82 and the guide unit 84, the test head 54 can be stably moved between the retracted position and the mounted position while being guided in a state where the horizontal movement (position and orientation) is restricted by the guide unit 84. As a result, the maintainability of the test head 54 is improved.

[0069] Furthermore, since this test head holding portion 80 is provided with a buffer portion 86 having a spring member 88, the distance and parallelism between the test head 54 and the pogo frame 58 can be properly maintained. As a result, it becomes possible to stably move the test head 54 between the mounting position and the retracted position.

[0070] Also, in the present embodiment, the pogo frame 58 is fixed to the head stage 52 by suction, and further, the test head 54, the pogo frame 58, and the probe card 56 are fixed by suction. Thereby, it is possible to secure the contact pressure necessary when electrically connecting between the test head 54 and the pogo frame 58 and between the probe card 56 and the pogo frame 58, and it is possible to suppress the influence due to the variation of the terminals connecting these.

[0071] Also, in the present embodiment, wafer level inspection is performed in a state where the test head 54, the pogo frame 58, the probe card 56, and the wafer chuck 50 are integrated with the head stage 52 as a reference. Therefore, it is possible to facilitate the contact operation of bringing the probe 66 into contact with the electrode pads of each chip of the wafer W while maintaining the parallelism between the wafer W and the probe card 56. That is, the probe 66 can be brought into contact with the electrode pads of each chip of the wafer W with an appropriate contact pressure, and it is possible to improve the accuracy of the wafer level inspection.

[0072] In addition, in the present embodiment, since the chuck guide mechanism 90 includes a chuck guide 98 (fixed portion 100) that is suction-fixed to the head stage 52 by vacuum suction or the like, and guides the wafer chuck 50 in the Z direction along the chuck guide 98, when the wafer chuck 50 is attracted toward the probe card 56 by decompression of the internal space S, displacement and inclination of the wafer chuck 50 can be prevented. Therefore, inclination and displacement due to uneven load caused by the components of the wafer chuck 50 can be prevented, and the transfer operation of the wafer chuck 50 can be stably performed while maintaining parallelism, and good contact can be realized between the electrode pads on the wafer W and the probes 66.

[0073] Further, in the present embodiment, since at least three height detection sensors 92 for detecting the relative distance from the wafer chuck 50 are provided on the head stage 52, it is possible to monitor the height position and inclination of the wafer chuck 50 based on the detection results of the respective height detection sensors 92. Thereby, when the wafer chuck 50 is attracted toward the probe card 56 by decompression of the internal space S, it is possible to confirm the amount of crushing (overdrive amount) of the probe 66, monitor the inclination of the wafer chuck 50, changes in the state during measurement, etc., and accurately determine whether the measurement is being correctly performed.

[0074] In the above-described embodiment, as the fixing method of the chuck guide mechanism 90, an adsorption method such as vacuum adsorption is shown. However, any well-known method can be adopted as long as the chuck guide 98 can be detachably fixed to the head stage 52, and a mechanical method using a clamp or the like may be used.

[0075] Also, in the above-described embodiment, the configuration in which the chuck guide mechanism 90 is provided on the wafer chuck 50 side and the chuck guide 98 (fixed portion 100) is adsorbed on the head stage 52 side is shown. However, the chuck guide mechanism 90 may be provided on the head stage 52 side and the chuck guide 98 (fixed portion 100) may be adsorbed on the wafer chuck 50 side.

[0076] In the above-described embodiment, the configuration in which the height detection sensor 92 is provided on the head stage 52 has been shown. However, any device capable of detecting the relative distance between the wafer chuck 50 and the head stage 52 may be used. For example, the height detection sensor 92 may be provided on the wafer chuck 50.

[0077] Although the probe of the present invention has been described in detail above, the present invention is not limited to the above examples, and various improvements and modifications may of course be made without departing from the gist of the present invention.

[0078] Note that the present invention includes the following technical ideas.

[0079] (Appendix 1) A probe having a plurality of measurement units stacked in multiple stages, wherein the measurement unit includes a test head, a probe card having probes, a pogo frame interposed between the test head and the probe card, a head stage having a pogo frame attachment portion to which the pogo frame is attached, a frame member that supports the head stage, a test head holding portion that is supported by the frame member and holds the test head, a wafer chuck that holds a wafer, a first adsorption fixing portion that fixes the test head and the pogo frame by adsorption, a second adsorption fixing portion that fixes the probe card and the pogo frame by adsorption, a wafer chuck fixing portion that detachably fixes the wafer chuck, mechanical lifting means for lifting and lowering the wafer chuck fixed to the wafer chuck fixing portion, an annular seal member that forms a sealed space between the wafer chuck and the probe card, and decompression means for decompressing the sealed space so that the wafer chuck is attracted toward the probe card. The probe performs an electrical inspection of the wafer in a state where the test head, the pogo frame, the probe card, and the wafer chuck are integrated with reference to the head stage. [[ID=|14]]

[0080] According to the invention described in Supplementary Note 1, the load on the test head is not directly applied to the head stage, deformation of the pogo frame is prevented, parallelism between the wafer and the probe card can be easily ensured, and the accuracy of wafer-level inspection can be improved.

[0081] (Supplementary Note 2) The test head holding part includes a lifting mechanism for moving the test head up and down, a guide part having a restricting surface for guiding the test head when the test head moves up and down, and a buffer part having a spring member for biasing the test head to the side opposite to the pogo frame. The probe according to Supplementary Note 1.

[0082] According to the invention described in Supplementary Note 2, the test head holding part has a lifting mechanism, a guide part, and a buffer part, and the test head is supported by the frame member by this test head holding part. Therefore, when the test head is moved up and down between the mounting position and the retracted position by the lifting mechanism, the lifting movement is guided while the position and orientation of the test head are restricted by the guide part, and the distance and parallelism between the test head and the pogo frame are properly maintained by the buffer part. Therefore, the load on the test head is not directly applied to the head stage, deformation of the pogo frame is prevented, parallelism between the wafer and the probe card can be easily ensured, and the accuracy of wafer-level inspection can be improved.

[0083] (Supplementary Note 3) The buffer part is provided in plurality at positions equidistant from the center of gravity of the test head. The probe according to Supplementary Note 2.

[0084] According to the invention described in Supplementary Note 3, since the load on the test head is evenly distributed, the horizontal posture of the test head can be properly maintained, and the effect of the present invention becomes more remarkable.

[0085] (Supplementary Note 4) The pogo frame mounting part has a suction surface for sucking and fixing the pogo frame. The probe according to any one of Supplementary Notes 1 to 3.

[0086] According to the invention described in Supplementary Note 4, the pogo frame is securely fixed to the head stage. It is preferable that the pogo frame mounting portion is provided with positioning means such as positioning pins for positioning the pogo frame with respect to the head stage.

[0087] (Supplementary Note 5) A wafer chuck for holding a wafer, a probe card provided so as to face the wafer chuck and having probes at positions corresponding to the respective electrode pads of the wafer, a test head held on the opposite side of the probe card from the wafer chuck by a test head holding portion, a pogo frame interposed between the probe card and the test head for electrically connecting the test head and the probe card, a head stage having a pogo frame mounting portion to which the pogo frame is attached, an annular seal member provided on the wafer chuck and formed so as to surround the wafer held by the wafer chuck, a wafer chuck fixing portion for detachably fixing the wafer chuck, mechanical lifting means for lifting and lowering the wafer chuck fixed to the wafer chuck fixing portion, a decompression means for decompressing the internal space formed by the probe card, the wafer chuck, and the seal member, and a guide means for guiding the movement of the wafer chuck while restricting the movement of the wafer chuck in a direction orthogonal to the moving direction of the wafer chuck when the wafer chuck is moved toward the probe card by the decompression of the internal space by the decompression means.

[0088] According to the invention described in Supplementary Note 5, when the wafer chuck is attracted toward the probe card by the decompression of the internal space by the decompression means, the movement of the wafer chuck is guided while the movement of the wafer chuck in a direction orthogonal to the moving direction of the wafer chuck is restricted by the guide means. Therefore, displacement and inclination of the wafer chuck can be prevented. Accordingly, the parallelism between the wafer and the probe card can be easily ensured, and the accuracy of wafer level inspection can be improved.

[0089] (Appendix 6) The probe according to Appendix 5, wherein the guiding means includes a bearing portion provided on the wafer chuck and a guide shaft portion that is detachably fixed to the head stage and is pivotally supported by the bearing portion.

[0090] The invention described in Appendix 6 shows one specific configuration of the guiding means.

[0091] (Appendix 7) The probe according to Appendix 5 or 6, wherein at least three guiding means are provided at different positions in a direction orthogonal to the moving direction of the wafer chuck.

[0092] According to the invention described in Appendix 7, it is possible to reliably prevent the inclination of the wafer chuck in a direction orthogonal to the moving direction of the wafer chuck.

[0093] (Appendix 8) The probe according to any one of Appendices 5 to 7, further comprising a height detection sensor for detecting the relative distance between the wafer chuck and the wafer chuck when the internal space is decompressed by the decompression means.

[0094] According to the invention described in Appendix 8, when the wafer chuck is attracted toward the probe card by decompressing the internal space by the decompression means, it is possible to set the wafer chuck to an appropriate height.

[0095] (Appendix 9) The probe according to Appendix 8, wherein at least three height detection sensors are provided at different positions in a direction orthogonal to the moving direction of the wafer chuck.

[0096] According to the invention described in Appendix 9, when the wafer chuck is attracted toward the probe card by decompressing the internal space by the decompression means, it is possible to accurately confirm the amount of probe crushing (overdrive amount), monitor the inclination of the wafer chuck, changes in the state during measurement, etc., and accurately determine whether the measurement is being performed correctly.

[0097] (Appendix 10) The test head holding part has a lifting mechanism for moving the test head up and down, a guide part having a regulating surface for guiding the test head when the test head moves up and down, and a buffer part having a spring member for biasing the test head to the side opposite to the pogo frame. The probe according to any one of Appendices 5 to 9.

[0098] According to the invention described in Appendix 10, when the test head is moved up and down between the mounting position and the retracted position by the lifting mechanism, the lifting and lowering movement is guided while the position and orientation of the test head are regulated by the guide part, and the distance and parallelism between the test head and the pogo frame are properly maintained by the buffer part. Therefore, the parallelism between the wafer and the probe card can be easily ensured, and the accuracy of wafer-level inspection can be improved.

[0099] (Appendix 11) The buffer part is provided in plurality at positions equidistant from the center of gravity of the test head. The probe according to Appendix 10.

[0100] According to the invention described in Appendix 11, since the load of the test head is evenly distributed, the horizontal posture of the test head can be properly maintained, and the effect of the present invention becomes more remarkable.

[0101] (Appendix 12) The pogo frame mounting part has a suction surface for sucking and fixing the pogo frame. The probe according to any one of Appendices 5 to 11.

[0102] According to the invention described in Appendix 12, the pogo frame is securely fixed to the head stage. It is preferable that the pogo frame mounting part is provided with positioning means such as positioning pins for positioning the pogo frame with respect to the head stage.

Explanation of Reference Numerals

[0103] 10…Prober, 12…Measurement unit, 14…Loader section, 16…Measurement section, 18…Load port, 20…Wafer cassette, 21…Operation panel, 22…Conveyor unit, 24…Conveyor arm, 30…Housing, 32A, 32B, 32C…Separate housing, 50…Wafer chuck, 52…Head stage, 54…Test head, 56…Probe card, 58…Pogo frame, 64…Chuck seal rubber, 66…Probe, 70…Alignment device, 72…Z-axis movement / rotation section, 74…X-axis moving stage, 76…Y-axis moving stage, 80…Test head holding section, 82…Lift mechanism, 84…Guide section, 85…Restricting surface, 86…Buffer section, 88…Spring member, 90…Chuck guide mechanism, 92…Height detection sensor, 94…Chuck guide holding section, 96…Bearing section, 98…Chuck guide, 100…Fixing section, 102…Chuck guide seal rubber, 104…Clearance holding member

Claims

【Claim 1】 a wafer chuck for holding a wafer; a probe card having a plurality of probes on a surface facing the wafer on the wafer chuck; a decompression means for sealing between the wafer chuck and the probe card to form a sealed space, decompressing the sealed space, and pulling the wafer chuck upward with reference to the probe card; a pogo frame disposed above the probe card, electrically connected to the probe card, and supported by a head stage; a test head evenly supported at an outer edge portion to reduce its own weight and placed on the pogo frame; comprising; a prober, wherein the test head, the pogo frame, and the probe card are integrated by fixing the pogo frame to the head stage, the probe card to the pogo frame, and the test head to the pogo frame, respectively.

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