Probe device

Abstract

This probe device for electrically measuring a substrate to be inspected in which an electrode pad part is arranged in a region to be inspected comprises a stage that holds the substrate to be inspected so that the electrode pad part is exposed, a flexible probe substrate, a probe arranged standing in a probe formation region on a surface of the probe substrate, a probe substrate holding member having a fixing part that holds a peripheral edge part of the probe substrate so that the probe faces the electrode pad part of the substrate to be inspected held by the stage, and an elastic member arranged on a rear surface side of the probe substrate, the elastic member urging the probe substrate so as to swell and curve toward the stage, and the probe substrate holding member being provided so as to be able to move relative to the stage along a direction at a right angle to the stage.

Description

Probe Device

[0001] The present invention relates to a probe device for electrically measuring and inspecting a substrate to be inspected by bringing probes into contact with electrode pads formed on the surface of the substrate to be inspected.

[0002] A large number of electrode pads are formed on the surface of a package substrate for mounting a semiconductor chip. A probe device equipped with multiple probes is used to measure and inspect the electrical characteristics of a test substrate, such as a package substrate. The probe device is required to simultaneously contact the electrode pads even if the heights of the electrode pads vary. A conventional probe device is known in which mechanical structures biased by spring coils are arranged two-dimensionally so that the tips of the probes can move forward and backward (protruding and retracting) (see, for example, Patent Document 1). Other known probes include a two-dimensional arrangement of multiple cantilever structures manufactured using MEMS (Micro Electro Mechanical Systems) technology.

[0003] Japanese Patent Application Laid-Open No. 2005-315775

[0004] In recent years, semiconductor chips have become increasingly highly integrated due to improvements in manufacturing process technology. Accordingly, the number of electrode pads on the surface of package substrates for mounting these semiconductor chips has increased, and the electrode pads have become finer and more closely spaced. However, it is difficult to two-dimensionally integrate and arrange mechanical probes with spring coils or probes manufactured using MEMS technology on the surface of package substrates so that they face the increasingly finer and more closely spaced electrode pads. When testing using a probe device, a test substrate, such as a package substrate, is placed on a substrate suction plate (stage). If the surface of this substrate suction plate is undulating or the test substrate itself is undulating, other probes or other parts of the probe device may interfere with the test substrate before the tip of the probe contacts the electrode pad of the test substrate, making contact between the probe and the electrode pad difficult. Furthermore, in probe devices, undulations may occur on the surface (imaginary surface) formed by connecting the tips of multiple probes, which can make contact between the probe and the electrode pad difficult.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a probe device that enables reliable measurement and inspection even when there is undulation on the surface of the substrate to be inspected, when the substrate to be inspected itself has undulations, when the stage on which the substrate to be inspected is placed has undulations on its surface, or when there is undulation on the surface connecting the tips of multiple probes.

[0006] In order to solve the above-mentioned problems, one aspect of the present invention is a probe device for performing electrical measurements on a test target substrate having electrode pad portions arranged in an area to be tested, the probe device comprising: a stage for holding the test target substrate so that the electrode pad portions are exposed; a flexible probe substrate; probes arranged upright in probe formation areas on the surface of the probe substrate; a probe substrate holding member having fixing portions for holding the peripheral edge of the probe substrate so that the probes face the electrode pad portions of the test target substrate held on the stage; and an elastic member arranged on the back side of the probe substrate, wherein the elastic member urges the probe substrate so that it bulges and curves toward the stage, and the probe substrate holding member is arranged to be relatively movable along a direction perpendicular to the stage.

[0007] In the above aspect, it is preferable that the elastic member is disposed between the probe substrate holding member and the probe substrate, and a gap is formed to allow deformation of the elastic member as the probe substrate is bent back.

[0008] In the above aspect, it is preferable that the elastic member is made of a resin material having elasticity, and the space has a capacity that can absorb the amount of deformation of the elastic member.

[0009] Another aspect of the present invention is a probe device for performing electrical measurements on a test substrate having electrode pad portions arranged in a test area on its surface, comprising: a probe substrate having probes arranged so that they stand upright in the probe formation area on the surface; a probe substrate holding member for holding the probe substrate; a stage having a fixing portion for holding the peripheral edge of the test substrate so that the electrode pad portions face toward the probe substrate holding member; and an elastic member arranged on the back side of the test substrate, wherein the elastic member urges the test substrate to bulge and curve toward the probe substrate holding member, and the probe substrate holding member is arranged to be movable relatively along a direction perpendicular to the stage.

[0010] In the above aspect, it is preferable that the elastic member is disposed between the stage and the substrate to be inspected, and a gap is formed to allow deformation of the elastic member due to bending back of the substrate to be inspected.

[0011] In the above aspect, it is preferable that the elastic member is made of a resin material having elasticity, and the space has a capacity that can absorb the amount of deformation of the elastic member.

[0012] The probe device according to the present invention has the effect of enabling reliable measurement and inspection even when the surface of the substrate to be inspected is undulating, when the substrate to be inspected itself has undulations, when the stage on which the substrate to be inspected is placed has undulations on its surface, or when the surface connecting the tips of multiple probes is undulating.

[0013] FIG. 1 is a bottom view showing a probe substrate holding member holding a probe substrate in a probe apparatus according to a first embodiment of the present invention, as viewed from below. FIG. 2-1 is a cross-sectional explanatory diagram of the probe apparatus according to the first embodiment of the present invention, showing a state in which the stage is deformed to bend upward. FIG. 2-2 is a cross-sectional explanatory diagram of the probe apparatus according to the first embodiment of the present invention, showing a state in which the stage is deformed to bend upward, and showing a state in which the probe is pressed against an electrode pad portion. FIG. 3-1 is a cross-sectional explanatory diagram of the probe apparatus according to the first embodiment of the present invention, showing a state in which the stage is deformed to bend downward. FIG. 3-2 is a cross-sectional explanatory diagram of the probe apparatus according to the first embodiment of the present invention, showing a state in which the stage is deformed to bend downward, and showing a state in which the probe is pressed against an electrode pad portion. FIG. 4-1 is a cross-sectional explanatory diagram of the probe apparatus according to a second embodiment of the present invention, showing a process in which the probe is positioned at an upper position facing the electrode pad portion and moved toward the electrode pad portion. Fig. 4-2 is a cross-sectional explanatory diagram of a probe device according to a second embodiment of the present invention, showing a state in which a probe is pressed against an electrode pad portion. Fig. 4-3 is a cross-sectional explanatory diagram of a probe device according to a second embodiment of the present invention, showing a process in which the probe substrate is raised and then the test target substrate is raised together with the fixing part. Fig. 4-4 is a cross-sectional explanatory diagram of a probe device according to a second embodiment of the present invention, showing a process in which the test target substrate is moved sideways together with the fixing part. Fig. 5 is a cross-sectional explanatory diagram showing a modified example of the probe device according to the first embodiment of the present invention.

[0014] The details of the probe device according to the embodiment of the present invention will be explained below with reference to the drawings. However, it should be noted that the drawings are schematic and the number of components, dimensions of each component, dimensional ratios, shapes, etc. may differ from the actual ones. Furthermore, the drawings may include parts where the dimensional relationships, ratios, and shapes differ from one another.

[0015] [First embodiment]

[0016] (Schematic Configuration of Probe Apparatus) The configuration of a probe apparatus 1A according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3B.

[0017] The test substrate 2, on which electrical measurement is performed using the probe device 1A according to this embodiment, is made of insulating resin, glass, ceramics, etc., and has a plurality of electrode pads 2A arranged in a detection area (not shown) in the center. Wiring (not shown) is connected to each of the electrode pads 2A.

[0018] The probe apparatus 1A includes a stage 3, a probe substrate 4, a plurality of probes 5, a probe substrate holding member 6, and an elastic member 7.

[0019] The stage 3 is a base having a rectangular planar shape, and is provided with a holding mechanism (not shown) for holding the inspection target substrate 2. The upper surface of the stage 3 is a mounting surface 31 on which the inspection target substrate 2 is mounted. As shown in FIG. 2-1, the inspection target substrate 2 is held in a predetermined area of ​​the mounting surface 31 so that the electrode pad portions 2A are exposed. The mounting surface 31 is processed to be flat, but it is also possible that the mounting surface 31 may be curved upward as shown in FIG. 2-1 depending on the environment in which the probe device 1A is placed.

[0020] As will be described later, it is also possible that the mounting surface 31 undulates downward from the center, as in the stage 3 shown in Figures 3-1 and 3-2. The probe device 1A according to this embodiment is capable of appropriate electrical measurement even when the mounting surface 31 is undulated, as shown in Figures 2-1 and 3-1, or when complex undulations occur. The test substrate 2 is held so that its underside is in close contact with the mounting surface 31 of the stage 3, exposing the electrode pads 2A.

[0021] As shown in FIGS. 1 and 2-1, the probe substrate 4 is made of a rectangular insulating resin and is flexible. The probe substrate 4 is designed so that it will not break or crack even when bent. A plurality of probes 5 are arranged upright in a probe formation region 4C set in the center of the surface (lower surface) 4A of the probe substrate 4. The probes 5 only need to be conductive members formed so as to protrude from the probe substrate 4, so the configuration is simple and a narrow pitch and miniaturization can be achieved. The protruding lengths of these probes 5 from the surface 4A are set to the same dimension.

[0022] The probe substrate holding member 6 has fixing portions 6A that hold the peripheral edge of the probe substrate 4 so that the probes 5 provided on the probe substrate 4 face the electrode pad portions 2A of the test target substrate 2 held on the stage 3. As shown in FIG. 2-1 , both end edges of the probe substrate 4 in the X direction are held by the fixing portions 6A of the probe substrate holding member 6 in a bent state.

[0023] 2-1, the elastic member 7 is disposed on the rear surface 4B side of the probe substrate 4. This elastic member 7 biases the probe substrate 4 so that it bulges and curves toward the stage 3. The elastic member 7 can be made of a material that has elasticity, such as various synthetic resins or rubbers, including polyimide, polyamide, polyester, polyethylene, polyvinyl alcohol, polypropylene, polycarbonate, and polystyrene.

[0024] Furthermore, in the probe substrate holding member 6, the elastic member 7 is disposed between the probe substrate 4 and the rear surface 4B thereof, and a gap 8 is formed which allows deformation of the elastic member 7 accompanying bending back of the probe substrate 4 when the probe substrate 4 is bent back from a bulging state. The surface (imaginary surface) formed by connecting the tips of the probes 5 is curved so as to protrude and come into contact with the test target substrate 2.

[0025] Furthermore, the probe substrate holding member 6 is provided so as to be relatively movable in a direction perpendicular to the stage 3 (the direction indicated by the arrow Z in the figure). Specifically, the probe substrate holding member 6 is provided so as to be movable up and down by a lifting drive mechanism (not shown).

[0026] (Operation, Action, and Effect of the Probe Device of the Present Embodiment) In the present embodiment, the surface (imaginary surface) formed by connecting the tips of the probes 5 is curved so as to protrude and contact the test target substrate 2. Therefore, by moving (lowering) the probe substrate holding member 6 toward the stage 3, the tips of the probes 5 start to contact the electrode pad portions 2A in order from the most protruding top, and by further lowering the probe substrate holding member 6, the probes 5 come into contact with all of the electrode pad portions 2A, as shown in FIG.

[0027] As described above, the probes 5 that come into contact with the electrode pad portions 2A receive a reaction force from the electrode pad portions 2A in order, which deforms the elastic member 7. That is, the elastic member 7 deforms as the probe substrate 4 is bent back. At this time, the gap 8 defined in the probe substrate holding member 6 has a sufficient capacity to absorb the amount of deformation of the elastic member 7. Therefore, the surface (imaginary surface) formed by connecting the tips of the multiple probes 5 can change to fit the surface connecting the tips of the electrode pad portions 2A, and all the probes 5 can reliably contact the corresponding electrode pad portions 2A, enabling electrical measurements.

[0028] 3-1 and 3-2 show the probe apparatus 1A according to the first embodiment of the present invention, in which the mounting surface 31 of the stage 3 is a concave, curved surface. According to the probe apparatus 1A according to this embodiment, as shown in FIG. 3-2, contact between the probes 5 and the electrode pads 2A can be reliably ensured. That is, even if the electrode pads 2A of the test target substrate 2 placed on the mounting surface 31 are located at the bottom of the concaves in the surface of the test target substrate 2, contact with the electrode pads 2A can be ensured because the probe substrate 4 has a plurality of probes 5 that bulge downward.

[0029] According to this embodiment, the probes 5 have a simple structure and are formed so as to protrude from the probe substrate 4, which has the effect of allowing the distance between the probes to be set to a short distance depending on the distance between the electrode pad portions 2A on the substrate to be inspected.

[0030] 2-2 and 3-2, in this embodiment, the elastic member 7 provides the probe 5 with cushioning properties that absorb the reaction force from the electrode pad portion 2 A, which has the effect of preventing damage to the probe 5 and the electrode pad portion 2 A. Therefore, according to this embodiment, it is not necessary to use a probe having a mechanical structure that is biased by a spring coil as in the conventional case, and the stability and precision of the test can be improved.

[0031] Second Embodiment Next, the configuration of a probe apparatus 1B according to a second embodiment of the present invention will be described with reference to FIGS. 4A to 4D.

[0032] The test substrate 2, on which electrical measurements are performed using the probe device 1B according to this embodiment, is made of insulating and flexible resin, and has a plurality of electrode pads 2A arranged in a predetermined detection area on the surface of the substrate. Wiring (not shown) is connected to each of the electrode pads 2A.

[0033] The probe device 1B comprises a probe substrate 4 on which probes 5 are arranged so as to stand upright in a probe formation area (not shown) on a surface 4A, a probe substrate holding member 6 that holds the probe substrate 4, a stage 3A having a fixing portion 9 that holds a peripheral portion 2C of the substrate 2 to be inspected so that the electrode pad portion 2A faces the probe substrate holding member 6, and an elastic member 7 that is arranged on the back surface 2B side of the substrate 2 to be inspected.

[0034] As shown in FIG. 4A, in this embodiment, the elastic member 7 biases the test target substrate 2 so that it bulges and curves toward the probe substrate holding member 6.

[0035] In this embodiment, the probe substrate holding member 6 is provided so as to be relatively movable along a direction perpendicular to the stage 3A (up and down direction).

[0036] The stage 3A has an elastic member 7 placed between the mounting surface 32 and the substrate 2 to be inspected, and when it changes from the state shown in Figure 4-1 to the state shown in Figure 4-2, a gap 10 is formed that allows deformation of the elastic member 7 as the substrate 2 to be bent back.

[0037] In this embodiment as well, the elastic member 7 is made of a resin material having elasticity, and the volume of the gap 10 is set to be able to absorb the amount of deformation of the elastic member 7 .

[0038] Next, the operation, function and effects of the probe apparatus 1B according to this embodiment will be described.

[0039] In the probe device 1B of this embodiment, as shown in FIG. 4-1, the probe 5 is placed at an upper position facing the electrode pad portion 2A, and the probe substrate holding member 6 is lowered to bring the probe 5 into contact with the electrode pad portion 2A as shown in FIG. 4-2, thereby enabling electrical measurement.

[0040] Next, as shown in Figure 4-3, the probe substrate holding member 6 is raised in the direction of arrow Z, and then the fixing portion 9 on the stage 3A is raised in the direction of arrow D, making the fixing portion 9 movable laterally relative to the stage 3A.

[0041] 4-4 shows the state in which the fixing portion 9 is being moved in the direction of the arrow E. This operation also makes it possible to move the test target substrate 2 in the direction of the arrow E so that another electrode pad portion 2A faces the probe 5.

[0042] According to this embodiment, the region to be inspected, on which the electrode pad portions 2A of the inspection target substrate 2 are formed, can be bent by the elastic member 7 so as to bulge toward the probe substrate holding member 6. Therefore, even if undulation occurs in the surface (imaginary surface) connecting the tips of the plurality of probes 5, the surface (imaginary surface) connecting the tips of the electrode pad portions 2A in the region to be inspected is bent so as to bulge, and the reaction force absorbing action of the elastic member 7 allows the tips of the probes 5 to reliably contact the electrode pad portions 2A.

[0043] In other words, since the surface (virtual surface) connecting the tips of the electrode pad portions 2A bulges upward, the components on the stage 3A side do not interfere with the probe substrate 4 side, and the probe 5 can be reliably brought into contact with the electrode pad portions 2A.

[0044] [Other Embodiments] The first and second embodiments of the present invention have been described above, but the descriptions and drawings that form part of the disclosure of the embodiments should not be understood to limit the present invention. Various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from this disclosure.

[0045] In the present invention, the test target substrate 2 can be applied to various substrates such as package substrates, printed wiring boards, flexible boards, multilayer wiring boards, and film carriers, each having a large number of electrode pads on its front or back surface.

[0046] For example, in the first embodiment, a pair of both side edges of the probe substrate 4 are held by the fixing portions 6A of the probe substrate holding member 6, but it is also possible to have a configuration in which all four sides of the probe substrate 4 are held. Similarly, in the second embodiment, it is also possible to have a configuration in which all four sides of the test target substrate 2 are held by the fixing portions 9.

[0047] In the first embodiment described above, one elastic member 7 is disposed on the rear surface 4B of the probe substrate 4. However, as shown in the modified example in FIG. 5 , when groups of probes 5 are provided in multiple regions (two in FIG. 5 ) on the front surface 4A of the probe substrate 4, elastic members 7 may be provided in regions on the rear surface 4B of the probe substrate 4 corresponding to each group of probes 5. As shown in FIG. 5 , piezoelectric actuators 11A and 11B may be interposed between each elastic member 7 and the probe substrate holding member 6. This configuration allows the voltage applied to the piezoelectric actuator 11A to be controlled to control the protrusion dimension P1 (protrusion dimension in the direction of arrow B) of the bulge portion 12 (see FIG. 5 ). Similarly, the voltage applied to the piezoelectric actuator 11B to be controlled to control the protrusion dimension P2 (protrusion dimension in the direction of arrow C) of the bulge portion 13. Thus, the configuration having multiple bulges 12 and 13 allows the probes 5 to reliably contact the electrode pad portions 2A present in multiple test regions 14 and 15 on the test target substrate 2.

[0048] 5, even when undulations occur on the mounting surface 31 of the stage 3 or on the surface of the test target substrate 2, by appropriately setting the protrusion dimensions P1, P2 of the respective bulges 12, 13, it is possible to reliably bring the probes 5 into contact with the electrode pad portions 2A and prevent interference between the stage 3 and the probe substrate holding member 6. Although the probe device 1A shown in FIG. 5 is configured to include two bulges 12, 13, it may also be configured to include three or more bulges.

[0049] Furthermore, in the second embodiment, one elastic member 7 is disposed on the rear surface 2B of the substrate 2 to be inspected. However, elastic members 7 may be interposed between the substrate 2 to be inspected and the stage 3A at multiple locations on the rear surface 2B of the substrate 2 to be inspected. Furthermore, piezo actuators similar to the piezo actuators 11A and 11B shown in FIG. 5 may be provided between each elastic member 7 and the mounting surface 31 of the stage 3. This configuration makes it possible to appropriately set the amount of protrusion deformation of the detection area (not shown) where the electrode pad portion 2A is formed (see detection areas 14 and 15 in FIG. 5 ) and the shape corresponding to the front surface 4A of the probe substrate 4. Note that, in addition to the piezo actuators 11A and 11B, various actuators may be used as means for displacing the elastic member 7.

[0050] REFERENCE SIGNS LIST 1A, 1B Probe device 2 Test target substrate 2A Electrode pad portion 2B Back surface 2C Periphery 3, 3A Stage 4 Probe substrate 4A Front surface 4B Back surface 4C Probe formation area 5 Probe 6 Probe substrate holding member 6A Fixing portion 7 Elastic member 8 Gap 9 Fixing portion 10 Gap 11A, 11B Piezo actuator 12, 13 Bulging portion 14, 15 Test target area 31 Mounting surface 32 Mounting surface

Claims

1. A probe device for performing electrical measurements on a test target substrate having electrode pad portions arranged in an area to be tested, comprising: a stage that holds the test target substrate so that the electrode pad portions are exposed; a flexible probe substrate; probes arranged upright in probe formation areas on the surface of the probe substrate; a probe substrate holding member having fixing portions that hold the peripheral edge of the probe substrate so that the probes face the electrode pad portions of the test target substrate held on the stage; and an elastic member arranged on the back side of the probe substrate, wherein the elastic member urges the probe substrate so that it bulges and curves towards the stage, and the probe substrate holding member is arranged to be movable relatively in a direction perpendicular to the stage.

2. The probe device according to claim 1, wherein the elastic member is disposed between the probe substrate holding member and the probe substrate, and a gap is formed between the probe substrate and the elastic member to allow deformation of the elastic member as the probe substrate is bent back.

3. The probe device according to claim 2, wherein the elastic member is made of a resin material having elasticity, and the gap has a capacity set to absorb the amount of deformation of the elastic member.

4. A probe device for making electrical measurements of a test target substrate having electrode pad portions arranged in a test area on its surface, comprising: a probe substrate having probes arranged so that they stand upright in the probe formation area on the surface; a probe substrate holding member for holding the probe substrate; a stage having a fixing portion for holding the peripheral edge of the test target substrate so that the electrode pad portions face towards the probe substrate holding member; and an elastic member arranged on the back side of the test target substrate, wherein the elastic member urges the test target substrate so that it bulges and curves towards the probe substrate holding member, and the probe substrate holding member is arranged to be movable relatively in a direction perpendicular to the stage.

5. A probe device according to claim 4, wherein the elastic member is disposed between the stage and the substrate to be inspected, and a gap is formed between the stage and the substrate to be inspected that allows deformation of the elastic member due to bending back of the substrate to be inspected.

6. The probe device according to claim 5, wherein the elastic member is made of a resin material having elasticity, and the gap has a volume that can absorb the amount of deformation of the elastic member.

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