Prova

Abstract

This invention provides a prober that can maintain parallelism between the probe card and the wafer, enabling high-precision wafer-level inspection. [Solution] The device comprises a wafer chuck 50, a probe card 56, a pressure reducing means for reducing the pressure in a sealed space S formed between the wafer chuck 50 and the probe card 56, a pogo frame 58 positioned above the probe card 56 and electrically connected to the probe card 56, and supported by a head stage 52, and a test head 54 that is supported by its outer edge to reduce its own weight and placed on the pogo frame 58. The pogo frame 58 is fixed to the head stage 52, the probe card 56 to the pogo frame 58, and the test head 54 to the pogo frame 58, so that the test head 54, the pogo frame 58, and the probe card 56 are integrated into one unit.

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 particularly to a prober having a plurality of measurement units stacked in multiple stages.

Background Art

[0002] The semiconductor manufacturing process has a number of processes, and various inspections are carried out in various manufacturing processes for quality assurance and yield improvement. 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 by the semiconductor devices are measured by the test head to perform a wafer-level inspection to electrically check whether they operate normally.

[0003] After the 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 chips with malfunctions are excluded from the assembly process. Further, the packaged final product is subjected to a shipping inspection.

[0004] The 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, wafer size is increasing and further miniaturization (integration) is progressing to reduce manufacturing costs, resulting in a very large number of chips formed on a single wafer. Consequently, the time required to inspect a single wafer with a prober has also increased, and there is a need to improve throughput. Therefore, to improve throughput, multi-probing is being implemented, which uses multiple probes to inspect multiple chips simultaneously. In recent years, the number of chips to be inspected simultaneously has increased even further, and attempts are being made to inspect all chips on a wafer simultaneously. As a result, the tolerance for alignment of the contact between the electrode pads and probes has become smaller, and there is a need to improve the positional accuracy of the prober's movement.

[0006] On the other hand, the simplest way to increase throughput is to increase the number of probers. However, increasing the number of probers increases the footprint of the probers on the manufacturing line. Increasing the number of probers also increases equipment costs. Therefore, there is a need to increase throughput while minimizing increases in footprint and equipment costs.

[0007] To address these problems, the applicant has proposed a prober having multiple measurement units stacked in a multi-stage configuration (see Patent Document 2). In this prober, since the multiple measurement units are stacked in a multi-stage configuration, wafer-level inspection can be performed for each measurement unit, thereby improving throughput while suppressing increases in installation area and equipment costs. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2009-60037 [Patent Document 2] Japanese Patent Publication No. 2014-150168 [Overview of the project] [Problems that the invention aims to solve]

[0009] By the way, in the prober disclosed in Patent Document 1, the test head is held by a holder and rotated from a retracted position away from the top plate (head stage) of the prober body to a horizontal position. Then, the test head is handed over to a lifting support mechanism provided on the prober body, and the lifting support mechanism lowers the test head to attach it to the prober body.

[0010] This headstage has probe cards attached to it, and in order to perform accurate inspections by making each probe on the probe card contact the electrode pads of each chip on the wafer, it is necessary to ensure parallelism between the probe card and the wafer. In particular, in the so-called simultaneous contact method, where all chips on the wafer are inspected at the same time, the precision of parallelism between the probe card and the wafer is even more important in order to make uniform contact between each probe on the probe card and the electrode pads of each chip on the wafer.

[0011] However, since the probe proposed by the present applicant has multiple measuring sections stacked in a multi-stage manner, it is difficult to implement a configuration like that disclosed in Patent Document 1 due to layout constraints.

[0012] For example, while it is possible to mount the test head directly onto the head stage, if the load of the test head on the head stage exceeds the allowable limit, the deformation of the head stage will become significant, making it impossible to maintain parallelism between the probe card and the wafer. As a result, this can lead to a decrease in the measurement accuracy of wafer-level inspection.

[0013] Furthermore, in the prober proposed by the applicant, the wafer chuck is pulled toward the probe card by reducing the pressure in the internal space formed between the probe card and the wafer chuck. However, due to the influence of uneven loads caused by the components of the wafer chuck, tilting or misalignment of the wafer chuck may occur. In this case, the parallelism between the probe card and the wafer will be poor, making it impossible to uniformly contact each probe on the probe card with the electrode pads of each chip on the wafer, resulting in a decrease in the measurement accuracy of wafer level inspection.

[0014] This invention has been made in view of these circumstances, and aims to provide a prober that can maintain parallelism between the probe card and the wafer and perform wafer-level inspection with high accuracy. [Means for solving the problem]

[0015] To achieve the above objective, the prober according to the present invention comprises 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 depressurization means for sealing the space between the wafer chuck and the probe card to form a sealed space, depressurizing the sealed space, and pulling the wafer chuck upward with respect to the probe card, a pogo frame positioned 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 with its outer edge evenly supported 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, enabling highly accurate wafer-level inspection. [Brief explanation of the drawing]

[0017] [Figure 1] External view showing the overall configuration of a prober according to one embodiment of the present invention. [Figure 2]Plan view showing the probe shown in FIG. 1 [Figure 3] Schematic diagram showing the configuration of the measurement unit [Figure 4] Schematic diagram showing the configuration of the measurement section [Figure 5] Figure showing the state after the wafer chuck is transferred to the head stage side [Figure 6] Plan view showing the planar arrangement relationship of the test head holding section [Figure 7] Side view of the test head holding section as viewed from the side

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 transport unit 22 that transports wafers W between each measuring unit 16 of the measuring unit 12 and the wafer cassette 20. The transport unit 22 is equipped with a transport unit drive mechanism (not shown) and is configured to be movable in the X and Z directions, and rotatable in the θ direction (around the Z direction). The transport unit 22 also includes a transport arm 24 that is configured to extend and retract back and forth by the transport unit drive mechanism. A suction pad (not shown) is provided on the upper surface of the transport arm 24, and the transport arm 24 holds the wafer W by vacuum adsorption of the back surface of the wafer W with this suction pad. As a result, the wafer W in the wafer cassette 20 is removed by the transport arm 24 of the transport unit 22 and transported to each measuring unit 16 of the measuring unit 12 while being held on its upper surface. After the inspection is completed, the inspected wafer W is returned to the wafer cassette 20 from each measuring unit 16 via the reverse path.

[0022] Figure 3 shows the configuration of the measurement unit 12.

[0023] As shown in Figure 3, the measurement unit 12 has a stacked structure (multi-stage structure) in which multiple measurement sections 16 are stacked in a multi-stage manner, and each measurement section 16 is arranged two-dimensionally along the X and Z directions. In this embodiment, as an example, four measurement sections 16 are stacked in the X direction in three stages in the Z direction. Each measurement section 16 has the same configuration and is equipped with a wafer chuck 50, probe card 56, etc., as will be described in detail later.

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

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

[0026] As shown in Figure 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 holder 80, which will be described in detail later. The test head 54 is electrically connected to the probes 66 of the probe card 56 and supplies power and test signals to each chip for electrical testing, as well as detecting the output signals from each chip to measure whether they are operating normally.

[0028] The headstage 52 is supported by a frame member 34 that constitutes part of the housing and has a pogo frame mounting portion 53 which 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 positioned state by the positioning pins. In this embodiment, as an example, the pogo frame mounting portion 53 has a suction surface that attracts and fixes the pogo frame 58, and the pogo frame 58 is attracted to the suction surface of the pogo frame mounting portion 53 and fixed by a suction means (not shown). This ensures that the pogo frame 58 is securely fixed to the headstage 52. Note that the method of fixing the pogo frame 58 is not limited to this embodiment, and mechanical fixing means such as screws may be used, for example.

[0029] The pogo frame 58 is equipped with numerous pogo pins (not shown) that electrically connect terminals formed on the lower surface of the test head 54 (the surface facing the pogo frame 58) to terminals formed on the upper surface of the probe card 56 (the surface facing the pogo frame 58). In addition, ring-shaped sealing members (not shown) are formed on the outer circumference 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. The space enclosed by the test head 54, the pogo frame 58, and the upper sealing member, and the space enclosed by the probe card 56, the pogo frame 58, and the lower sealing member are depressurized by a suction means (not shown), thereby integrating the test head 54, the pogo frame 58, and the probe card 56. The upper and lower surfaces of the pogo frame 58 are examples of a first suction fixing part and a second suction fixing part, respectively.

[0030] The probe card 56 is equipped with multiple probes 66, such as cantilevers and spring pins, which are arranged to correspond to the electrodes of each chip on 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 terminals provided on the upper surface of the probe card 56 (the surface facing the pogo frame 58). Therefore, when the test head 54, pogo frame 58, and probe card 56 are integrated, each probe 66 is electrically connected to the terminals of the test head 54 via the pogo frame 58. In this example, the probe card 56 is equipped with a large number of probes 66 corresponding to the electrodes of all chips on the wafer W to be inspected, and each measurement unit 16 performs simultaneous inspection of all chips on the wafer W held in the wafer chuck 50.

[0031] The wafer chuck 50 holds and fixes the wafer W by vacuum suction or the like. The wafer chuck 50 is detachably supported and fixed to an alignment device 70, which will be described later. The alignment device 70 moves the wafer chuck 50 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.

[0032] Furthermore, an elastic ring-shaped sealing member (hereinafter referred to as "chuck seal rubber") 64 is provided on the outer circumference of the upper surface (wafer mounting 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, which will be described later, the chuck seal rubber 64 comes into contact with the lower surface of the head stage 52, forming an internal space S (see Figure 5) surrounded by the wafer chuck 50, the probe card 56 (head stage 52), and the chuck seal rubber 64. Then, the internal space S is depressurized by a suction means (depressurization means) (not shown), and the wafer chuck 50 is pulled 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, and the inspection can begin. Note that the chuck seal rubber 64 is an example of an annular sealing member.

[0033] Inside the wafer chuck 50, a heating / cooling mechanism (not shown) is provided as a heating / cooling source so that the chip can be subjected to electrical characteristic testing at high temperatures (e.g., up to 150°C) or low temperatures (e.g., down to -40°C). As the heating / cooling mechanism, any known suitable heater / cooler can be used. For example, a double-layer structure consisting of a heating layer of a surface heater and a cooling layer with passages for a cooling fluid, or a single-layer heating / cooling device with a cooling tube embedded in a heat conductor wrapped around a heating element, are all conceivable. Furthermore, instead of electric heating, a system that circulates a thermal 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 positioning between the wafer W held in the wafer chuck 50 and the probe card 56, and includes a Z-axis moving / rotating unit 72 that detachably supports and fixes the wafer chuck 50 and moves the wafer chuck 50 in the Z-axis direction and rotates it in the θ direction with the Z-axis as the center of rotation, an X-axis moving table 74 that supports the Z-axis moving / rotating unit 72 and moves in the X-axis direction, and a Y-axis moving table 76 that supports the X-axis moving table 74 and moves in the Y-axis direction.

[0035] The Z-axis moving / rotating section 72, the X-axis moving table 74, and the Y-axis moving table 76 are each configured to move or rotate the wafer chuck 50 in a predetermined direction by a mechanical drive mechanism including at least a motor. The mechanical drive mechanism is, for example, a ball screw drive mechanism combining a servo motor and a ball screw. However, it is not limited to a ball screw drive mechanism, and may also be composed of a linear motor drive mechanism, a belt drive mechanism, etc. Note that the Z-axis moving / rotating section 72 is an example of a mechanical lifting and lowering means.

[0036] Alignment devices 70 are provided for each stage (see Figure 3), and are configured to move between multiple measuring units 16 located on each stage by an alignment device drive mechanism (not shown). That is, the alignment device 70 is shared among multiple (four in this example) measuring units 16 located on the same stage, and moves between multiple measuring units 16 located on the same stage. Once the alignment device 70 has moved to each measuring unit 16, it is fixed in a predetermined position by a positioning fixing device (not shown), and the aforementioned alignment device drive mechanism moves the wafer chuck 50 in the X, Y, Z, and θ directions to perform relative alignment between the wafer W held in the wafer chuck 50 and the probe card 56. Although not shown, the alignment device 70 is equipped with a needle position detection camera and a wafer alignment camera to detect the relative positional relationship between the electrodes of the wafer W chip held in the wafer chuck 50 and the probe 66.

[0037] In this embodiment, the alignment device 70 (Z-axis moving / rotating section 72) has a suction port (an example of a wafer chuck fixing section) on its upper surface, and the wafer chuck 50 is fixed by suction using a suction means (not shown). However, any known method can be used to fix the wafer chuck 50, as long as it can be fixed detachably, and a mechanical method such as a clamp is also acceptable. Furthermore, 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 remains constant at all times.

[0038] In this embodiment, in addition to the above-described configuration, a chuck guide mechanism 90 is provided to guide the wafer chuck 50 in the Z direction (vertical direction) to prevent misalignment or tilting of the wafer chuck 50 in the X and Y directions (horizontal direction) when the wafer chuck 50 is pulled toward the probe card 56 by reducing the pressure of the internal space S. The chuck guide mechanism 90 is an example of a guiding means.

[0039] The chuck guide mechanism 90 is provided in parallel in multiple locations along the circumferential direction of the outer edge of the wafer chuck 50, specifically the outer circumference of the chuck guide holder 94 integrated with the wafer chuck 50. The chuck guide mechanism 90 functions as a guide mechanism that restricts the horizontal movement of the wafer chuck 50 while moving it parallel to the Z direction by adsorption and fixing the chuck guide 98 (described later) to the head stage 52 by vacuum adsorption or the like, before the wafer chuck 50 is pulled toward the probe card 56 by the depressurization of the internal space S. For this reason, at least three chuck guide mechanisms 90 are provided on the wafer chuck 50 (chuck guide holder 94) at different positions in the horizontal direction (X, Y direction) perpendicular to the direction of movement of the wafer chuck 50 (Z direction). In this example, although not shown in the figures, three chuck guide mechanisms 90 are provided on the chuck guide holder 94 at equal intervals (every 120 degrees) along the circumferential direction (only one is shown in Figure 4).

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

[0041] The chuck guide mechanism 90 includes a bearing portion 96 formed in the 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 direction) is restricted by the bearing portion 96. The bearing portion 96 is composed of, for example, a ball bearing.

[0042] The chuck guide 98 is rotatably supported on the bearing portion 96, and its upper part is provided with a fixing portion 100 for detachably fixing the chuck guide 98 to the head stage 52. A ring-shaped sealing member (hereinafter referred to as "chuck guide seal rubber") 102 is provided on the upper surface of the fixing portion 100, and inside the chuck guide seal rubber 102 is provided a suction port (not shown) connected to a suction means (not shown), and a clearance holding member 104 for maintaining a constant distance (gap) between the fixing portion 100 and the head stage 52. 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 this configuration, the wafer chuck 50 is moved to a predetermined height by the Z-axis movement / rotation unit 72, and the chuck guide seal rubber 102 is brought into contact with the head stage 52. Then, when the internal space Q formed between the chuck guide seal rubber 102, the head stage 52, and the fixing part 100 is depressurized by a suction means (not shown), the fixing part 100 of the chuck guide 98 is attracted to and fixed to the head stage 52. At this time, a certain gap is secured between the head stage 52 and the chuck guide 98 by the clearance holding member 104 described above, so excessive attraction by the fixing part 100 of the chuck guide 98 is suppressed, and tilting of the chuck guide 98 fixed to the head stage 52 can be prevented. When the wafer chuck 50 is pulled 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. This prevents tilting and misalignment due to uneven loading by the components of the wafer chuck 50, allowing for stable transfer of the wafer chuck 50 while maintaining parallelism, and enabling good contact between the electrode pads on the wafer W and the probe 66.

[0044] Furthermore, in this 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 pulled toward the probe card 56 by reducing the pressure of the internal space S. For this reason, the head stage 52 is provided with at least three height detection sensors 92 at mutually different positions in the X and Y directions (horizontal directions) that are perpendicular to the Z direction (vertical direction), which is the direction of movement of the wafer chuck 50 (only one is shown in Figure 4). With this configuration, it is possible to monitor the height position and inclination of the wafer chuck 50 from the detection results of each height detection sensor 92. Therefore, when the wafer chuck 50 is pulled toward the probe card 56 by reducing the pressure of the internal space S, it is possible to check the amount of compression (overdrive amount) of the probe 66, the inclination of the wafer chuck 50, and changes in the state during measurement, making it possible to accurately determine whether the measurement is being performed correctly.

[0045] Next, the configuration of the test head holder 80 will be explained in detail with reference to Figures 4 to 7. Figure 6 is a plan view showing the planar arrangement of the test head holder 80, and Figure 7 is a side view of the test head holder 80 as seen from the side. In Figure 6, the test head 54 is shown with a dashed line for convenience of explanation.

[0046] As shown in Figures 4 to 7, the test head holder 80 is interposed between the receiving portion 54a on the upper surface side of the test head 54 and the frame member 34. The lower end of the test head holder 80 is mounted on the frame member 34, and its upper end supports the receiving portion 54a of the test head 54. In other words, the test head 54 is supported by the frame member 34 by the test head holder 80, so that the load of the test head 54 is not directly applied to the head stage 52, the parallelism between the probe card 56 and the wafer W can be maintained, and wafer level inspection can be performed with high precision. The specific configuration of the test head holder 80 is as follows.

[0047] The test head holding section 80 includes a lifting mechanism 82 for raising and lowering the test head 54 in the Z direction, a guide section 84 for guiding 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 section 86 for maintaining a constant distance (clearance) and parallelism between the test head 54 and the probe card 56.

[0048] The lifting mechanism 82 is composed of, for example, an air cylinder or an electric mechanism, and raises 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 its upper end 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 raise 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. As a result, the load of the test head 54 is distributed to each lifting mechanism 82A and 82B, so that the test head 54 can be raised and lowered stably and reliably in the Z direction. The receiving portion 54a of the test head 54 has a flange surface (projecting surface) that protrudes 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 section 84 has a restricting surface 85 facing the side of the test head 54 (the surface perpendicular to the X direction), and the side of the receiving portion 54a of the test head 54 comes into contact with this restricting surface 85, thereby restricting the horizontal movement (X and Y directions) of the test head 54 while guiding the movement of the test head 54 in the Z direction. The number and arrangement of the guide sections 84 are not particularly limited as long as they can restrict the position and orientation of the test head 54. In this embodiment, as an example, four guide sections 84A to 84D are provided so as to sandwich the sides of the receiving portions 54a on both sides of the test head 54. Specifically, guide sections 84A and 84B are arranged on both sides of the lifting mechanism 82A, and guide sections 84C and 84D are arranged on both sides of the lifting mechanism 82B. In other words, guide sections 84A and 84C, and guide sections 84B and 84D are each arranged in positions that face each other with the test head 54 in between. As a result, when the test head 54 is raised or lowered vertically, 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 section 84 (84A to 84D).

[0050] The buffer section 86 has a spring member 88 interposed between a spring receiving section 87 fixed to the frame member 34 and a receiving section 54a of the test head 54. This spring member 88 has a biasing force that biases the test head 54 upward (i.e., away from the pogo frame 58) and has the function of maintaining the correct distance and parallelism between the test head 54 and the pogo frame 58. In this embodiment, as an example, there are multiple buffer sections 86A to 86D, each of which supports the end of the receiving section 54a of the test head 54. That is, each buffer section 86A to 86D is positioned at an equidistant distance from the center of gravity of the test head 54. As a result, the load on the test head 54 is evenly distributed, making it possible to maintain the correct horizontal position of the test head 54.

[0051] With the above configuration, the test head 54 is guided by the guide section 84 (84A to 84D) while its movement in the X and Y directions (horizontal direction) is restricted, and it moves in the Z direction (vertical direction) by the lifting mechanism 82 (82A, 82B). This allows the test head 54 to move stably between the retracted position and the mounting position.

[0052] Furthermore, when the test head 54 is moved to the mounting position by the lifting mechanism 82 (82A, 82B), the spring member 88 of the buffer section 86 (86A~86D) can properly maintain the distance and parallelism between the test head 54 and the pogo frame 58. Therefore, once the parallelism between the test head 54 and the pogo frame 58 is adjusted during initial setup, the parallelism is always maintained even when the test head 54 is raised or lowered, eliminating the need for further parallelism adjustment of the test head 54 and reducing the time and effort required for adjustment.

[0053] Next, an inspection method using the prober 10 of this embodiment will be described.

[0054] In the inspection method using the prober 10 of this embodiment, an integration process is performed as a preliminary step to integrate the test head 54, pogo frame 58, and probe card 56. Specifically, the integration process is carried out as follows.

[0055] In the integration process, first, the pogo frame 58 is attached to the head stage 52 by vacuum suction or the like, and then the probe card 56 is attached to the pogo frame 58 by vacuum suction or the like. Next, the lifting mechanism 82 moves the test head 54 to the mounting position while restricting its movement in the X and Y directions (horizontal direction) with the guide section 84. At this time, the test head 54 is not in contact with the pogo frame 58, and the spring members 88 of the buffer section 86 (86A~86D) maintain the correct distance (clearance) and parallelism between the test head 54 and the pogo frame 58. Finally, the test head 54 is attached to the pogo frame 58 by vacuum suction or the like. As a result, the test head 54, pogo frame 58, and probe card 56 are integrated into one unit.

[0056] After the integration process is completed in this manner, the prober 10 performs the following operations.

[0057] First, in the loader unit 14, the wafer W in the wafer cassette 20 is removed by the transport arm 24 of the transport unit 22 and transported to each measuring section 16 of the measuring unit 12 while being held on the upper surface of the transport arm 24.

[0058] Meanwhile, in the measurement unit 12, the alignment device 70 provided at each stage moves to a predetermined measurement section 16, and the wafer chuck 50 is positioned on the upper surface of the alignment device 70 and fixed by suction.

[0059] Next, the alignment device 70 moves the wafer chuck 50 to a predetermined transfer position. Then, when the wafer W is transferred from the transport 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 apparatus 70 moves the wafer chuck 50 holding the wafer W to a predetermined alignment position, detects the relative positional relationship between the electrodes of the wafer W chip held in the wafer chuck 50 and the probe 66 using a needle position detection camera (not shown) and a wafer alignment camera, and moves the wafer chuck 50 in the X, Y, Z, and θ directions based on the detected positional relationship to perform relative alignment between the wafer W held in 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 (a position facing the probe card 56), and raises the wafer chuck 50 using the Z-axis movement and rotation unit 72 of the alignment device 70 until the chuck guide seal rubber 102 is at a height that contacts the head stage 52. At this time, it is preferable that the height of the wafer chuck 50 after raising (the height of the upper surface of the wafer chuck 50) is higher than the tip position (contact position) of the probe 66. In this configuration, each probe 66 of the probe card 56 contacts the electrode pad of each chip of the wafer W in an overdrive state, so the tip of the probe 66 bites into the surface of the electrode pad and forms a needle mark on the surface of the electrode pad. This allows the oxide film formed on the electrode pad to be removed by the contact of the probe 66, and also prevents the probe 66 from shifting position (lateral displacement) in the X and Y directions (horizontal direction) due to disturbances (vibrations) that occur when the wafer chuck 50 is transferred from the alignment device 70 to the head stage 52 (probe card 56 side). Furthermore, if the influence of the oxide film formed on the electrode pad is small, the height of the wafer chuck 50 after lifting may be 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 comes into contact with the head stage 52 as described above, the fixing part 100 is fixed to the head stage 52 by suction (depressurization means) (not shown) by reducing the pressure in the internal space Q formed inside the chuck guide seal rubber 102, the head stage 52, and the fixing part 100.

[0063] Next, after releasing the suction fixation of the wafer chuck 50 by the Z-axis movement / rotation unit 72, 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) while detecting the height position of the wafer chuck 50 with a plurality of height detection sensors 92 provided on the head stage 52. At this time, as described above, the chuck guide 98 (fixing part 100) of the chuck guide mechanism 90 is suction fixed to the head stage 52, so the wafer chuck 50 is guided to move in the Z direction (vertical direction) while its movement in the X and Y directions (horizontal direction) is restricted by the chuck guide 98. As a result, the wafer chuck 50 is pulled toward the probe card 56 without tilting or misalignment, the probe card 56 and the wafer chuck 50 become in close contact, and each probe 66 of the probe card 56 contacts the electrode pads of each chip of the wafer W with uniform contact pressure.

[0064] Furthermore, in this embodiment, the height position and inclination of the wafer chuck 50 are determined based on the detection results of each height detection sensor 92, and a process is performed to determine whether these values ​​are within an appropriate range. This determination process is performed by the control device described above. This makes it possible to accurately determine whether the measurement is being performed correctly, as well as to check the amount of compression (overdrive) of the probe 66, monitor the inclination of the wafer chuck 50, and check for changes in the state during measurement when the wafer chuck 50 is pulled toward the probe card 56 by reducing the pressure of the internal space S.

[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), the test head 54, pogo frame 58, probe card 56, and wafer chuck 50 become integrated, as shown in Figure 5, and each probe 66 of the probe card 56 makes contact with the electrode pads of each chip on the wafer W with uniform contact pressure. This makes it possible to start wafer level inspection. Subsequently, power and test signals are supplied from the test head 54 to each chip on the wafer W via each probe 66, and electrical operation tests are performed by detecting the signals output from each chip.

[0066] 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, where contact operations are performed in the same procedure, and wafer level inspections are carried out sequentially.

[0067] As described above, according to this embodiment, the test head 54 is supported by the frame member 34 by interposing the test head holding portion 80 between the receiving portion 54a of the test head 54 and the frame member 34. Therefore, the load of the test head 54 is not directly applied to the head stage 52, and deformation of the pogo frame 58 is prevented, making it easy to ensure parallelism between the wafer W and the probe card 56, thereby improving the accuracy of wafer level inspection.

[0068] In particular, according to this embodiment, the test head holding unit 80 is equipped with a lifting mechanism 82 and a guide unit 84, so that the test head 54 can move stably between the retracted position and the mounting position while being guided with its horizontal movement (position and orientation) restricted by the guide unit 84. This improves the maintainability of the test head 54.

[0069] Furthermore, since the test head holder 80 is equipped with a buffer 86 having a spring member 88, the distance and parallelism between the test head 54 and the pogo frame 58 can be properly maintained. This makes it possible to stably move the test head 54 between the mounting position and the retracted position.

[0070] In this embodiment, the pogo frame 58 is fixed to the head stage 52 by suction, and the test head 54, pogo frame 58, and probe card 56 are also fixed by suction. This ensures the necessary contact pressure for electrical conductivity between the test head 54 and the pogo frame 58, and between the probe card 56 and the pogo frame 58, thereby suppressing the effects of variations in the terminals connecting them.

[0071] Furthermore, in this embodiment, wafer-level inspection is performed with the test head 54, pogo frame 58, probe card 56, and wafer chuck 50 integrated together with respect to the head stage 52. Therefore, the contact operation of bringing the probe 66 into contact with the electrode pads of each chip on the wafer W can be easily performed while maintaining the parallelism between the wafer W and the probe card 56. In other words, the probe 66 can be brought into contact with the electrode pads of each chip on the wafer W with appropriate contact pressure, thereby improving the accuracy of wafer-level inspection.

[0072] Furthermore, in this embodiment, the chuck guide mechanism 90 is provided with a chuck guide mechanism 90 that guides the wafer chuck 50 in the Z direction along the chuck guide 98 while the chuck guide 98 (fixing part 100) of the chuck guide mechanism 90 is fixed to the head stage 52 by vacuum suction or the like. Therefore, when the wafer chuck 50 is pulled toward the probe card 56 by reducing the pressure in the internal space S, displacement or tilting of the wafer chuck 50 can be prevented. Consequently, tilting or 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 performed stably while maintaining parallelism, making it possible to achieve good contact between the electrode pads on the wafer W and the probe 66.

[0073] Furthermore, in this embodiment, the head stage 52 is equipped with at least three height detection sensors 92 that detect the relative distance to the wafer chuck 50, making it possible to monitor the height position and tilt of the wafer chuck 50 based on the detection results of each height detection sensor 92. This makes it possible to check the amount of compression (overdrive) of the probe 66, monitor the tilt of the wafer chuck 50, monitor changes in the state during measurement, and accurately determine whether the measurement is being performed correctly when the wafer chuck 50 is pulled toward the probe card 56 by reducing the pressure of the internal space S.

[0074] In the above-described embodiment, a suction method such as vacuum suction was shown as the fixing method for the chuck guide mechanism 90. However, any well-known method can be used as long as the chuck guide 98 can be detachably fixed to the head stage 52, and a mechanical method such as a clamp is also acceptable.

[0075] Furthermore, in the above-described embodiment, the chuck guide mechanism 90 is provided on the wafer chuck 50 side and the chuck guide 98 (fixing part 100) is attached to the head stage 52 side. However, the chuck guide mechanism 90 may be provided on the head stage 52 side and the chuck guide 98 (fixing part 100) may be attached to the wafer chuck 50 side.

[0076] Furthermore, although the above-described embodiment shows a configuration in which the height detection sensor 92 is provided on the head stage 52, any sensor capable of detecting the relative distance between the wafer chuck 50 and the head stage 52 is acceptable. 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 be made without departing from the spirit of the present invention.

[0078] Furthermore, this invention includes the following technical concepts.

[0079] (Note 1) A prober having a plurality of measuring units stacked in a multi-stage manner, wherein the measuring unit comprises a test head, a probe card having a probe, a pogo frame interposed between the test head and the probe card, a head stage having a pogo frame mounting portion to which the pogo frame is attached, a frame member supporting the head stage, a test head holding portion supported by the frame member and holding the test head, a wafer chuck holding a wafer, a first suction fixing portion fixing the test head and the pogo frame by suction, and the probe card and the pogo frame A prober having a second suction fixing part for fixing the wafer chuck by suction, a wafer chuck fixing part for detachably fixing the wafer chuck, a mechanical lifting means for raising and lowering the wafer chuck fixed to the wafer chuck fixing part, an annular sealing member for forming a sealed space between the wafer chuck and the probe card, and a depressurization means for depressurizing the sealed space so that the wafer chuck is pulled toward the probe card, wherein the prober performs electrical testing of the wafer with the test head, pogo frame, probe card and wafer chuck integrated together with respect to the head stage.

[0080] According to the invention described in Appendix 1, the load of 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] (Note 2) The prober according to Note 1, wherein the test head holding portion comprises a lifting mechanism for moving the test head up and down, a guide portion having a restricting surface for guiding the test head when it moves up and down, and a buffer portion having a spring member for biasing the test head toward the opposite side from the pogo frame.

[0082] According to the invention described in Appendix 2, the test head holder has a lifting mechanism, a guide, and a buffer, and the test head is supported by the frame member through this test head holder. 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, and the distance and parallelism between the test head and the pogo frame are properly maintained by the buffer. Consequently, the load of 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] (Note 3) The buffer portion is provided in multiple locations equidistant from the center of gravity of the test head, as described in Note 2.

[0084] According to the invention described in Appendix 3, the load on the test head is evenly distributed, so the horizontal position of the test head can be properly maintained, and the effects of the present invention become even more pronounced.

[0085] (Note 4) The prober according to any one of Notes 1 to 3, wherein the pogo frame mounting portion has a suction surface for adsorbing and fixing the pogo frame.

[0086] According to the invention described in Appendix 4, the pogo frame is securely fixed to the head stage. Preferably, the pogo frame mounting portion is provided with positioning means such as positioning pins to position the pogo frame relative to the head stage.

[0087] (Note 5) A wafer chuck for holding a wafer, a probe card provided opposite the wafer chuck and having probes at positions corresponding to each electrode pad 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 and 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, and the wafer chuck provided and held by the wafer chuck A prober comprising: an annular sealing member formed to surround the wafer; a wafer chuck fixing portion for detachably fixing the wafer chuck; a mechanical lifting means for raising and lowering the wafer chuck fixed to the wafer chuck fixing portion; a depressurization means for depressurizing the internal space formed by the probe card, the wafer chuck, and the sealing member; and a guide means for guiding the movement of the wafer chuck while restricting movement in a direction perpendicular to the direction of movement of the wafer chuck when the wafer chuck is moved toward the probe card by the depressurization of the internal space by the depressurization means.

[0088] According to the invention described in Appendix 5, when the wafer chuck is pulled toward the probe card by reducing the internal space pressure using the depressurization means, the movement of the wafer chuck is guided by the guide means while restricting movement in a direction perpendicular to the direction of movement of the wafer chuck, thereby preventing misalignment and tilting of the wafer chuck. Therefore, parallelism between the wafer and the probe card can be easily ensured, and the accuracy of wafer level inspection can be improved.

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

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

[0091] (Note 7) The prober according to Note 5 or 6, wherein the guide means is provided at least three at different positions in a direction perpendicular to the direction of movement of the wafer chuck.

[0092] According to the invention described in Appendix 7, it is possible to reliably prevent the wafer chuck from tilting in a direction perpendicular to the direction of movement of the wafer chuck.

[0093] (Note 8) The prober according to any one of Notes 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 depressurized by the depressurization means.

[0094] According to the invention described in Appendix 8, when the wafer chuck is pulled toward the probe card by reducing the internal space pressure using the depressurization means, it becomes possible to set the wafer chuck to an appropriate height.

[0095] (Note 9) The prober according to Note 8, wherein at least three height detection sensors are provided at different positions in a direction perpendicular to the direction of movement of the wafer chuck.

[0096] According to the invention described in Appendix 9, when the wafer chuck is pulled toward the probe card by reducing the internal space pressure using a depressurization means, it becomes possible to check the amount of probe compression (overdrive), monitor the tilt of the wafer chuck, monitor changes in the state during measurement, and accurately determine whether or not the measurement is being performed correctly.

[0097] (Note 10) The prober according to any one of Notes 5 to 9, wherein the test head holding portion comprises a lifting mechanism for moving the test head up and down, a guide portion having a restricting surface for guiding the test head when it moves up and down, and a buffer portion having a spring member for biasing the test head toward the opposite side from the pogo frame.

[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 movement is guided while the position and orientation of the test head are restricted by the guide section, and the distance and parallelism between the test head and the pogo frame are properly maintained by the buffer section. 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] (Note 11) The prober described in Note 10, wherein the buffer portion is provided in multiple locations equidistant from the center of gravity of the test head.

[0100] According to the invention described in Appendix 11, the load on the test head is evenly distributed, so the horizontal position of the test head can be properly maintained, and the effects of the present invention become even more pronounced.

[0101] (Note 12) The prober according to any one of Notes 5 to 11, wherein the pogo frame mounting portion has a suction surface for adsorbing and fixing the pogo frame.

[0102] According to the invention described in Appendix 12, the pogo frame is securely fixed to the head stage. Preferably, the pogo frame mounting portion is provided with positioning means such as positioning pins to position the pogo frame relative to the head stage. [Explanation of symbols]

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

Claims

[Claim 1] A wafer chuck that holds the wafer, A probe card having a plurality of probes on the surface facing the wafer on the wafer chuck, A depressurization means that seals the space between the wafer chuck and the probe card to form a sealed space, depressurizes the sealed space, and pulls the wafer chuck upward with respect to the probe card, A pogo frame is positioned above the probe card and electrically connected to the probe card, and is supported by the headstage. A test head, supported at its outer edge to reduce its own weight, is placed on the pogo frame, Equipped with, A prober in which 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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