Inspection unit and inspection device

Abstract

The present disclosure aims to provide an inspection unit that can easily inspect the conductivity between conductive patterns even on substrates with different spacing between conductive patterns. [Solution] An inspection unit according to one aspect of the present disclosure is a unit for inspecting the conductivity between a plurality of conductive patterns formed on a substrate, comprising a plurality of probes that contact each of the conductive patterns, a plurality of holders that hold each of the plurality of probes, and spacing adjustment means for changing the interval between the plurality of probes to an arbitrary interval, wherein the spacing adjustment means comprises a cam having a plurality of grooves formed on its circumferential surface that engage with each of the plurality of holders, and a drive unit that rotates the cam in the circumferential direction.

Description

Technical Field

[0001] The present disclosure relates to an inspection unit and an inspection apparatus for inspecting the conductivity of a plurality of conductive patterns formed on a substrate.

Background Art

[0002] On the surface of a substrate such as a semiconductor wafer, a solar cell panel, or a printed wiring board, there are some on which a plurality of conductive patterns for conducting electricity are formed. In such a substrate, it is inspected whether the plurality of conductive patterns are electrically connected with a desired potential difference, or whether the plurality of conductive patterns are surely insulated from each other. An inspection apparatus for confirming that a plurality of conductive patterns are insulated from each other is known (Japanese Unexamined Patent Application Publication No. 2021-106467).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the inspection apparatus described in the above publication, the insulation of a plurality of electrode layers (conductive patterns) divided by a plurality of dividing grooves on the surface of a solar cell (substrate) is inspected by bringing a plurality of terminals (probes) of a probe unit into contact with the plurality of electrode layers. In the above inspection apparatus, when the pitch (interval) of a plurality of conductive patterns formed on a substrate is changed, it is necessary to prepare a probe unit in which a plurality of probes corresponding to this interval are arranged. Therefore, the inspection of a plurality of types of conductive patterns having different pitches may become complicated.

[0005] In view of the above circumstances, an object of the present disclosure is to provide an inspection unit that can easily inspect the conductivity between the conductive patterns even for a substrate having different intervals between the conductive patterns. [Means for solving the problem]

[0006] An inspection unit according to one aspect of the present disclosure, made to solve the above problems, is a unit for inspecting the conductivity between a plurality of conductive patterns formed on a substrate, comprising a plurality of probes that contact each of the conductive patterns, a plurality of holders that hold each of the plurality of probes, and spacing adjustment means for changing the interval between the plurality of probes to an arbitrary interval, wherein the spacing adjustment means comprises a cam having a plurality of grooves formed on its circumferential surface that engage with each of the plurality of holders, and a drive unit that rotates the cam in the circumferential direction. [Effects of the Invention]

[0007] An inspection unit according to one aspect of this disclosure can easily inspect the conductivity between conductive patterns even on substrates with different spacings between conductive patterns. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic front view showing an inspection unit according to one embodiment of the present disclosure. [Figure 2] Figure 2 is a schematic side view showing the inspection unit in Figure 1. [Figure 3] Figure 3 is a schematic plan view showing the unfolded circumferential surface of the cam of the spacing adjustment mechanism provided in the inspection unit of Figure 1. [Figure 4] Figure 4 is a schematic plan view showing the inspection unit in Figure 1 with the probes 1 spaced at their minimum. [Figure 5] Figure 5 is a schematic plan view showing the inspection unit in Figure 1 with the probe 1 spacing maximized. [Figure 6] Figure 6 is a schematic plan view showing an inspection unit different from the inspection unit in Figure 1. [Modes for carrying out the invention]

[0009] [Description of Embodiments in this Disclosure] First, the embodiments of this disclosure will be listed and described.

[0010] [1] An inspection unit according to one aspect of the present disclosure is a unit for inspecting the conductivity between a plurality of conductive patterns formed on a substrate, comprising a plurality of probes that contact each of the conductive patterns, a plurality of holders that hold each of the plurality of probes, and spacing adjustment means for changing the interval between the plurality of probes to an arbitrary interval, wherein the spacing adjustment means comprises a cam having a plurality of grooves formed on its circumferential surface that engage with each of the plurality of holders, and a drive unit that rotates the cam in the circumferential direction.

[0011] Since the inspection unit is equipped with spacing adjustment means for adjusting the spacing between multiple probes that contact each of the multiple conductive patterns, it is possible to easily inspect the conductivity between the multiple conductive patterns even if the substrate has substrates with different spacings between the multiple conductive patterns.

[0012] [2] In the above [1], the cam may be cylindrical or columnar, and the plurality of probes may be arranged in a line in the axial direction of the cam. By having a cylindrical or columnar cam and arranging the probes in a line in the axial direction of the cam, the ease of adjusting the probes to any desired interval can be improved.

[0013] [3] In the above [1] or [2], the plurality of holders may move in the axial direction of the cam by the rotation of the cam. Moving the holders in the axial direction makes it easier to adjust the probes to any desired interval.

[0014] [4] In the above [2] or [3], the plurality of grooves may be formed in a range of less than 360° on the circumferential surface of the cam, and may be formed linearly such that one end of adjacent grooves is close to each other and the other end is far from each other in the unfolded plan view of the circumferential surface. With this configuration, the holder can be easily moved to be close to or far from each other at equal intervals in the axial direction.

[0015] An inspection apparatus according to an embodiment of the present disclosure includes any one of the inspection units from [1] to [4] above and an appearance inspection unit that inspects the presence or absence of abnormalities from the appearance of the conductive pattern.

[0016] Since the inspection apparatus includes the inspection unit and the appearance inspection unit, it is possible to easily and surely inspect the quality of the substrate.

[0017] [Details of the Mode for Carrying Out the Invention] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings as appropriate. Note that the drawings are diagrams schematically showing the embodiments, and the shapes, sizes, scales, arrangements, etc. of each component (member) may be different from the actual ones.

[0018] <Inspection Unit> The inspection unit inspects the conductivity between a plurality of conductive patterns formed on a substrate. That is, the inspection unit inspects the continuity or insulation between a plurality of conductive patterns, or the potential of each of the plurality of conductive patterns. As shown in FIGS. 1 and 2, the inspection unit includes a plurality of probes 10 that contact each of the conductive patterns (not shown) formed on the substrate, a plurality of holders 20 that hold each of the plurality of probes 10, and an interval adjustment means 30 that changes the holders 20 at an arbitrary interval. The interval adjustment means 30 has a cam 31 in which a plurality of grooves 312 engaged with each of the plurality of holders 20 are formed on the circumferential surface 311, and a drive unit (not shown) that rotates the cam 31.

[0019] The conductive pattern inspected by the inspection unit is not particularly limited, and may be formed on a substrate such as a semiconductor wafer, a semiconductor substrate for a solar cell panel, or a printed wiring board.

[0020] Although not shown in the figure, the inspection unit 1 includes a conveyance unit that conveys the substrate, a first power source that supplies electricity to the probe 10 or the conductive pattern, a second power source that supplies electricity to the drive unit, a control unit that controls the drive unit to rotate the cam 31 at an arbitrary angle, a measuring instrument that measures conduction, insulation, potential, etc. measured by the contact between the probe 10 and the conductive pattern, or is electrically connected to these. The first power source and the second power source may be the same power source. The control unit may control the conveyance unit.

[0021] The inspection unit makes the tips of a plurality of probes 10 contact each of the plurality of conductive patterns of the substrate conveyed to the inspection position by the conveyance unit, and inspects the conductivity between the plurality of conductive patterns. The conveyance unit preferably has a function of discharging the inspected substrate from the inspection position and conveying another substrate to the inspection position after the inspection. The conveyance unit may have a function of moving the substrate conveyed to the inspection position into contact with the probe 20 and moving it in the normal direction of the substrate surface so as to be separated from the probe 20 after the inspection.

[0022] 〔Probe〕 The probe 10 is not particularly limited and may be a known probe, but it is preferably stretchable in the axial direction. By using a probe that is stretchable in the axial direction, its tip can be brought into contact with the plurality of conductive patterns with a substantially uniform pressing force, improving the accuracy of the inspection. Also, even when the heights (distance from the surface of the substrate) of the surfaces of each of the plurality of conductive patterns are different, the tip can be surely brought into contact with the plurality of conductive patterns.

[0023] 〔Holder〕 The holder 20 that holds the probe 10 engages with the groove 312 of the cam 31. The holder 20 in this embodiment is a rod-shaped member that bends at approximately a right angle in a side view, and has an engaging portion 21 that engages with the groove 312 and extends approximately normal from the circumferential surface 311 of the cam 31, and a holding portion 22 that extends from this engaging portion 21 in a direction approximately parallel to the surface of the substrate and approximately perpendicular to the axial direction of the cam 30. The probe 10 is held in the holder 20 so as to be approximately parallel to the normal direction of the surface of the substrate.

[0024] To improve the sliding performance with respect to the groove 312, a known sliding member such as a bearing may be provided at the end of the engaging portion 21 that engages with the groove 312.

[0025] The material used to form the holder 20 is not particularly limited and may be, for example, a metallic material or a resin material, but it is preferable that it be a non-conductive material (insulating material).

[0026] [Interval adjustment means] The spacing adjustment means 30 includes a cam 31 and the drive unit. Multiple grooves 312 are formed on the circumferential surface 311 of the cam 31, which engage with the ends of the engaging portions 21 of each of the multiple holders 20. The drive unit is not particularly limited and may be, for example, a known electric motor.

[0027] The cam 31 may be cylindrical or columnar. For example, the cross-sectional shape of the cam may be semicircular, elliptical, polygonal, etc., but a circular shape improves the ease of adjusting the spacing between the multiple holders 20 that engage with the groove 312, and also improves the ease of selecting the adjustment range (adjustment width). In this embodiment, the cam 31 will be described as being cylindrical.

[0028] The material used to form the cam 31 is not particularly limited, but if the holder 20 is made of a conductive material, the cam 31 may be made of a non-conductive material (insulating material), and if the holder 20 is made of a non-conductive material, the cam 31 may be made of a conductive material. It is preferable that both the holder 20 and the cam 31 be made of non-conductive materials.

[0029] Each groove 312 formed on the circumferential surface of the cam 31 may be formed in an annular shape around the circumferential surface, but it is preferable that they are not formed around the circumferential surface and that each groove 312 has a pair of ends. In other words, it is preferable that the grooves 312 be formed in a range of less than 360° on the circumferential surface of the cam 31.

[0030] Furthermore, each groove 312 is preferably formed linearly, as shown in the unfolded plan view of the circumferential surface of the cam 31 in Figure 3, such that one end of adjacent grooves 312 is close to each other and the other end is far from each other. Each groove 312 is preferably formed at equal intervals in the axial direction of the cam 31. The grooves 312 are preferably formed symmetrically on a virtual plane perpendicular to the axis of the cam 31, and the angle of inclination with respect to the virtual plane increases as the groove moves away from the virtual plane. In other words, the angle between the groove 312 close to the virtual plane and the virtual plane is small, and the angle gradually increases as the groove moves away from the virtual plane. With this configuration, as the cam 31 rotates, the distance between adjacent holders 20 in the axial direction of the cam 31 can be easily gradually decreased or increased at equal distances. In other words, the distance between multiple probes 10 can be easily narrowed or widened at equal intervals. Furthermore, the spacing between the multiple probes 10 can be adjusted steplessly between the minimum spacing shown in Figure 4 and the maximum spacing shown in Figure 5. The virtual plane is preferably located at the midpoint of the cam 31 in the axial direction.

[0031] If an odd number of holders 20 are arranged and the holder (center holder) 20C located at the midpoint does not move the cam 31 in the axial direction, the cam 40 does not need to have a groove that engages with the center holder 20C. Alternatively, the cam 40 may have a groove that engages with the center holder 20C, but in this case, the groove is formed in a direction substantially perpendicular to the axial direction. That is, the groove is formed so as not to have an inclination angle with respect to the virtual surface.

[0032] The multiple holders 20 (including the central holder 20C) are preferably arranged in a line along the axial direction of the cam 31. In other words, the probes 10 are preferably arranged in a line along the axial direction of the cam 31. Furthermore, each probe 10 is preferably arranged so that its distance (height) from the substrate is approximately equal. The multiple holders 20 are preferably mounted on a stage (not shown) or the like so that they can move freely along the axial direction.

[0033] The inspection unit may include a pair of cams. Specifically, as shown in Figure 6, it may include the above-mentioned cam (first cam) 31 and second cam 61, a plurality of holders 20, 40 that engage with grooves 312, 612 of the respective cams 31, 61, and probes (not shown) held by each of the plurality of holders 20, 40.

[0034] The first cam 31 and the second cam 61 are positioned with their axes approximately parallel to each other and rotate synchronously by the drive unit. The holder 40 of the second cam 61 is positioned between the holders 20 of the first cam 31, and the probes held by each holder 20 and 40 are preferably arranged in a single line (on a straight line). With this configuration, the number of probes can be easily increased and the spacing between the probes can be reduced. Therefore, inspection can be easily performed even when many conductive patterns are formed on the substrate. In addition, inspection can be easily performed even when the pitch between multiple conductive patterns formed on the substrate is small (narrow). Figure 6 shows the minimum spacing between the holders 20 and 40.

[0035] <Inspection equipment> The inspection device comprises the inspection unit and an appearance inspection unit that inspects the appearance of the conductive pattern for any abnormalities.

[0036] [Visual Inspection Unit] The above-mentioned visual inspection unit is not particularly limited and may include, for example, an imaging unit including a known camera, and a determination unit that analyzes the image captured by the imaging unit to determine whether or not there is an abnormality in the conductive pattern.

[0037] The above-mentioned visual inspection unit may have two imaging units. Specifically, it may include a transport unit that transports the substrate parallel to its surface, a first imaging unit that captures the surface of the substrate being transported by the transport unit as a first image, a second imaging unit 30 that captures a second image which is an enlarged view of the abnormal area found in the first image, and a determination unit that determines the presence or absence of the abnormal area from the first image and measures the amount of unevenness of the abnormal area (the difference in height of the surface at the abnormal area) from the second image.

[0038] The first imaging unit may include, for example, a line sensor camera, and capture the surface of the substrate being transported by the transport unit as the first image. Since the line sensor camera can take continuous shots at high speed, it can efficiently capture the surface of the transported substrate. Therefore, the processing speed of imaging by the first imaging unit can be improved.

[0039] The second imaging unit is, for example, positioned downstream of the first imaging unit in the transport direction of the transport unit. The second imaging unit may include, for example, a high-resolution optical device such as a quantitative phase microscope, and may capture a second image that magnifies the abnormal area found in the first image. The second imaging unit may target substrates that the determination unit has determined to have the abnormal area from the first image, and may not target substrates that have been determined not to have the abnormal area.

[0040] A quantitative phase microscope can quantitatively obtain phase information of reflected light from a substrate, allowing for the detection of surface irregularities (height differences) on the substrate at the nanometer level. Therefore, it is suitable for inspecting substrates and other materials requiring high precision.

[0041] If the determination unit determines that a substrate does not have any abnormalities based on the first image above, it may be transported from the first imaging unit to the inspection unit for inspection of the potential difference or insulation of the conductive pattern. If the determination unit determines that a substrate has any abnormalities based on the first image above, it may be transported from the first imaging unit to the second imaging unit.

[0042] The determination unit processes the first image and the second image. If the first imaging unit includes a line sensor camera, the determination unit sequentially receives images of a portion of the substrate surface transmitted from the line sensor camera, processes these images to generate an image of the entire surface, and determines whether or not there are any abnormal areas on the surface. If the determination unit finds an abnormal area, it generates its coordinate information. Based on this coordinate information, the transport unit transports the substrate so that the abnormal area is within the imaging range of the second imaging unit.

[0043] The determination unit described above is not particularly limited and may be, for example, a well-known personal computer. The determination unit may include a control unit that controls the operation of the transport unit, the first imaging unit, and the second imaging unit. The determination unit may also perform the measurement by the inspection unit or the determination of the inspection results by the inspection unit.

[0044] The above-described appearance inspection unit may include a distance measuring unit for measuring the distance between the substrate surface and the second imaging unit. Specifically, the distance measuring unit measures the distance between the surface and the second imaging unit and transmits the measured value to the determination unit. The determination unit determines whether or not the measured value coincides with the focus of the second imaging unit.

[0045] The transport unit may have an adjustment mechanism that moves the substrate in the direction normal to the substrate surface to adjust the distance. Specifically, if the measured value does not coincide with the focus of the second imaging unit, the adjustment mechanism may move the stage on which the substrate is placed in the direction normal to bring the surface to coincide with the focus.

[0046] <Testing Method> The inspection method using the inspection device preferably comprises the steps of: imaging the surface of a transported substrate with a first imaging unit; determining the presence or absence of abnormal areas on the substrate surface from a first image captured by the first imaging unit; transporting the substrate determined to have abnormal areas from the first image to a second imaging unit; imaging the abnormal areas of the transported substrate with the second imaging unit; measuring the amount of unevenness of the abnormal areas from a second image captured by the second imaging unit; determining whether the measured value of the amount of unevenness is less than or equal to a preset value or greater than the preset value; transporting the substrate determined to have no abnormal areas in the first image, and the substrate determined to have an amount of unevenness measured in the second image less than or equal to the preset value, to the inspection unit; and inspecting the potential difference or insulation of the conductive pattern on the substrate transported to the inspection unit.

[0047] The above inspection method may further include a step of measuring the distance between the second imaging unit and the substrate surface before the step of imaging the abnormal area.

[0048] [Process of imaging with the first imaging unit] The first imaging unit captures an image of the surface of the substrate being transported. The first imaging unit may capture an image of the entire surface at once and transmit it to the determination unit, or it may capture an image of a part of the surface sequentially and transmit it to the determination unit.

[0049] [First judgment process] The determination unit determines from the received first image whether there are any abnormalities on the surface, and if it determines that there are abnormalities, it generates coordinate information of the abnormalities. If the determination unit determines that there are no abnormalities on the surface, it sends a command to the transport unit to transport the substrate to the inspection unit. If the determination unit determines that there are abnormalities on the surface, it sends a command to the second imaging unit to transport the substrate and the coordinate information to the transport unit.

[0050] The method for determining the presence or absence of abnormal areas by the above-mentioned determination unit is not particularly limited, and for example, the presence or absence of abnormal areas may be determined by the brightness in the first image. Specifically, in the first image, areas where the brightness is less than a predetermined value (first setting value) may be determined as abnormal areas, and areas where the brightness is equal to or greater than the first setting value may be determined as not abnormal areas (normal areas).

[0051] [Process of transporting to the second imaging unit] The transport unit transports the substrate, which has been determined to have an abnormal area from the first image, to the second imaging unit. Based on the coordinate information, the transport unit transports the substrate so that the abnormal area is located within the imaging range of the second imaging unit.

[0052] [Measurement process] In the measurement process, the distance measuring unit measures the distance between the second imaging unit and the substrate surface. The distance measuring unit transmits the measured value to the determination unit, which determines whether the measured value matches the focal length of the second imaging unit. If the determination unit determines that the measured value does not match the focal length, it sends a command to the transport unit to move the substrate in the direction normal to the substrate surface using the adjustment mechanism. The determination unit moves the substrate so that the difference between the measured value and the focal length is eliminated.

[0053] The distance measuring unit may be positioned between the first imaging unit and the second imaging unit. In other words, the distance measuring unit may be positioned on the path through which the substrate is transported from the first imaging unit to the second imaging unit. The distance measuring unit may also be configured integrally with the second imaging unit (as part of the second imaging unit) and positioned together with the second imaging unit.

[0054] [Process for imaging abnormal areas] The second imaging unit captures the abnormal area of ​​the transported substrate as a second image. The second image is a magnified view of the abnormal area. The second imaging unit transmits the captured second image to the determination unit.

[0055] [Process for measuring the amount of unevenness] The determination unit measures the amount of unevenness (difference in height on the substrate surface) of the abnormal area from the received second image.

[0056] [Second judgment process] The determination unit determines whether the measured value of the amount of unevenness is less than or equal to a preset value (second setting value) or greater than the second setting value. If the amount of unevenness exceeds the second setting value, the determination unit determines the substrate to be defective and terminates the inspection of the substrate by the inspection device. If the amount of unevenness is less than or equal to the second setting value, the determination unit transmits a command to the transport unit to transport the substrate to the inspection unit.

[0057] [Process of transporting to the inspection unit] Substrates that are determined to have no defects in the first image above, and substrates whose amount of unevenness measured in the second image above is determined to be less than or equal to the second set value above, are transported to the inspection unit by the transport unit. In other words, in the first determination step, substrates that are determined to have no defects are transported to the inspection unit, and substrates that are determined to have defects are transported to the second imaging unit. This prevents substrates to be inspected after the first substrate from accumulating in the inspection device, and allows for efficient quality evaluation of multiple substrates. Furthermore, in the second determination step, substrates whose amount of unevenness exceeds the second set value above are not transported to the inspection unit, thus improving the accumulating suppression effect and allowing for more efficient quality evaluation.

[0058] [Inspection process] The circuit boards transported to the inspection unit undergo a conductivity test of the conductive patterns. Circuit boards that are found to have continuity or insulation, or that meet the required potential, are deemed good products, and the inspection by the inspection device is terminated.

[0059] [Other embodiments] The above embodiments do not limit the configuration of the present invention. Accordingly, the above embodiments allow for the omission, substitution, or addition of components of each part of the above embodiments based on the description herein and common technical knowledge, and all such omissions, substitutions, or additions should be interpreted as falling within the scope of the present invention.

[0060] The inspection unit does not necessarily have to include the transport unit described above. In other words, the operator may place the substrate to be inspected at the inspection position.

[0061] In the above embodiment, the holder of the inspection unit was described as a rod-shaped member that bends at approximately a right angle in a side view, but the shape of the holder is not particularly limited. For example, it may be a straight rod-shaped or plate-shaped member. [Industrial applicability]

[0062] An inspection unit according to one aspect of this disclosure can efficiently inspect the conductivity of conductive patterns on a substrate, and is therefore suitable for use in the manufacturing and quality inspection of semiconductor wafers, semiconductor substrates for solar panels, printed wiring boards, and the like. [Explanation of Symbols]

[0063] 10 probes 20,40 holder 20C holder (center holder) 21 Engaging part 22 Holding part 30 Spacing adjustment means 31,61 Cam 311 Peripheral surface 312,612 grooves

Claims

1. A unit for inspecting the conductivity between multiple conductive patterns formed on a substrate, Multiple probes that contact each of the above conductive patterns, Multiple holders for each of the above multiple probes, Interval adjustment means for changing the interval between the multiple probes described above to any desired interval, Equipped with, The above interval adjustment means, A cam having multiple grooves formed on its circumferential surface that engage with each of the multiple holders described above, A drive unit that rotates the above cam in the circumferential direction and An inspection unit having the following features.

2. The inspection unit according to claim 1, wherein the cam is cylindrical or columnar, and the plurality of probes are arranged in a line in the axial direction of the cam.

3. The inspection unit according to claim 2, wherein the plurality of holders move in the axial direction of the cam by the rotation of the cam.

4. The inspection unit according to claim 3, wherein the plurality of grooves are formed in a range of less than 360° on the circumferential surface of the cam, and are formed linearly such that one end of adjacent grooves is close to each other and the other end is far from each other in the unfolded plan view of the circumferential surface.

5. An inspection unit according to any one of claims 1 to 4, An external inspection unit that inspects for abnormalities in the above circuit board from its appearance, An inspection device equipped with the following features.

Images