Press holding mechanism and press inspection device using it, wafer transfer device

Abstract

The objective of this invention is to provide a presser holding mechanism for accurately checking whether a wafer component is attached to a specified location on a presser, even when the wafer component is small, as well as a presser inspection device and a wafer transfer device using the same. A press holding mechanism is provided for holding a press that transfers wafer components located on a transfer source substrate to a transfer destination substrate by simultaneously attaching multiple wafer components using adhesive properties. The press holding mechanism holds the opposite side of the adhesive side of the press and irradiates the press with light.

Description

Technical Field

[0001] The present invention relates to a presser holding mechanism for holding a presser, a presser inspection device and a chip transfer device using the same. The presser is used when picking up chip parts from a transfer source substrate and transferring them to a transfer destination substrate. Prior Art

[0002] Recently, with the rapid development of μLED displays, there has been increasing interest in chip transfer equipment that picks up chip components densely arranged on a transfer source substrate and mounts them on a transfer destination substrate with an enlarged pitch.

[0003] As such a wafer transfer device, a method using a wafer presser that simultaneously attaches and detaches a plurality of wafer components on an adhesive surface is known (e.g., Patent Document 1). 11 (a) as shown in the cross-sectional view, the presser 2 is provided with an adhesive portion 21 on the plate-shaped presser body 20, the interval between the adhesive portion 21 is an integer multiple of the pitch of the chip parts C on the transfer source substrate S0.

[0004] As shown in FIG11(a), after the presser 2 held by the pickup head 101 is positioned so that the wafer component C is disposed directly below the adhesive portion 21, the adhesive portion 21 is brought into close contact with the wafer component C as shown in FIG11(b). At this stage, if the adhesive portion 21 has a greater adhesive force on the wafer component C than on the transfer source substrate S0, the presser 2 is raised (moved away from the transfer source substrate S0), and the wafer component C in close contact with the adhesive portion 21 is picked up from the transfer source substrate S0 (FIG11(c)).

[0005] The presser 2 that has picked up the chip component C is held by the mounting head 102. After being positioned at a predetermined location on the transfer destination substrate S1 as shown in Figure 12(a), it is then crimped onto the transfer destination substrate S1 as shown in Figure 12(b). At this stage, if the adhesive force of the adhesive portion 21 on the chip component C is weakened relative to the bonding force on the transfer destination substrate S1 by heating, etc., then when the presser 2 is raised (moved away from the transfer destination substrate S1), the chip component C is released from the presser 2 and mounted on the transfer destination substrate S1 (Figure 12(c)). Here, it is feasible to reduce the adhesive force of the adhesive portion 21 by heating the chip component C while strengthening the bonding force between the chip component C and the transfer destination substrate S1.

[0006] As described above, the presser 2 transfers the wafer component C picked up from the transfer source substrate S0 while attached to the adhesive portion 21, as shown in Figure 13(a). As shown in Figure 13(b), the adhesive portion 21 after the transfer is free of the wafer component C. Figure 13(c) shows the structure of the wafer transfer apparatus performing this operation, including the pickup device 5 and the mounting device 6.

[0007] In such a wafer transfer apparatus, the pickup device 5 should hold the wafer components C on all adhesive sections 21, and the mounting device 6 should transfer all wafer components C attached to the adhesive sections 21 to the transfer destination substrate S1. However, in the pickup device 5, as shown in FIG14(a), wafer components C may not be attached to some adhesive sections 21. Furthermore, in the mounting device 6, wafer components C that cannot be mounted on the transfer destination substrate S1 may remain on the adhesive sections 21, as shown in FIG14(b).

[0008] The phenomenon of missed detection, such as that shown in FIG14(a) or FIG14(b), is a serious problem in the wafer transfer process. Therefore, it is preferable to arrange a presser inspection device 7 between the pickup device 5 and the mounting device 6. The presser inspection device 7 confirms whether the wafer component C is attached to the predetermined portion (adhesive portion 21) of the presser 2 in the state of FIG13(a) and inspects whether the wafer component C remains on the presser 2 in the state of FIG13(b).

[0009] Figure 16 shows the configuration of a typical visual inspection device used to observe the state of the wafer component holding surface of the presser 2. In Figure 16, the imaging mechanism, camera 4, captures the wafer component holding surface of the presser 2 illuminated by light from a reflection light source 40. This image is analyzed to determine the presence or absence of wafer components C. For example, Figure 17(a) shows the wafer component holding surface after pickup and before mounting. The IRC corresponding to the portion holding the wafer component C is brighter, while the adhesive portion 21 corresponding to the portion not holding the wafer component C is darker. Figure 17(b) clearly shows the wafer component holding surface after mounting, showing that the wafer component C remains in the brighter portion. [Prior Art Literature] [Patent Document]

[0010] [Patent Document 1] Japanese Patent Application Publication No. 2019-175961 Summary of the Invention

[0011] [Problems to be solved by the invention]

[0012] When inspection is performed using the structure shown in FIG16 , the state of the reflected image varies depending on the light intensity or direction of the reflecting light source 40. If the brightness of the image is used to determine whether the chip component C is present, it is difficult to set the threshold value, and there is a possibility of erroneous judgment.

[0013] In particular, as the chip parts C are further miniaturized or the number of chip parts C attached to one presser 2 increases, the number of pixels of the camera 4 for one chip part C decreases, making it difficult to make accurate judgments.

[0014] The present invention is completed in view of the above problems and provides a presser holding mechanism for accurately checking whether chip parts are attached to a specified position of a presser even if the chip parts are small, and a presser inspection device and a chip transfer device using the same. [Technical means to solve the problem]

[0015] In order to solve the above-mentioned problems, the invention of technical solution 1 is a presser holding mechanism. It is the one that keeps the presser, The above-mentioned presser is a device that transfers the chip components located on the transfer source substrate to the transfer destination substrate by utilizing adhesiveness to simultaneously attach multiple chip components. The presser holding mechanism holds the opposite side of the adhesive surface of the presser and irradiates light toward the presser.

[0016] The invention of technical solution 2 is a presser holding mechanism as in technical solution 1, and includes: An adsorption portion having a function of adsorbing and holding the opposite side of the adhesive surface of the aforementioned presser and having light transmittance; and The lighting part is arranged on the side of the adsorption part opposite to the surface adsorbing the presser, and irradiates light to the presser through the adsorption part.

[0017] The invention of technical solution 3 is a presser holding mechanism as in technical solution 2, wherein: The adsorption part includes: a lower plate, which is composed of a light-transmitting plate with adsorption holes; an upper plate, which is light-transmitting; and a side plate; the adsorption part can form a decompression space inside.

[0018] The invention of technical solution 4 is a presser holding mechanism as in technical solution 2, wherein: The adsorption portion has a porous region, and the porous region closely adsorbs and holds the presser.

[0019] The invention of technical solution 5 is a presser inspection device, which includes: a presser holding mechanism of any one of technical solutions 1 to 4; and a camera mechanism, which obtains an image through the aforementioned presser when irradiating light to the aforementioned presser.

[0020] The invention of technical solution 6 is the presser inspection device of technical solution 5, further comprising: The image processing mechanism determines whether a chip component is attached to a specified position of the presser based on the image obtained by the camera mechanism.

[0021] The invention of technical solution 7 is a wafer transfer device, which includes: A pickup device that uses the aforementioned presser to simultaneously pick up a plurality of wafer components from the aforementioned transfer source substrates; A mounting device that uses the aforementioned presser to simultaneously mount a plurality of chip components on the aforementioned transfer destination substrate; and The presser inspection device of technical solution 5 or 6.

[0022] The invention of technical solution 8 is a wafer transfer device as in technical solution 7. It has the function of the aforementioned presser after the picking action is performed in the aforementioned picking device by the aforementioned presser inspection device, and the function of the aforementioned presser after the mounting action is performed in the aforementioned mounting device by the aforementioned presser inspection device. [Effects of the Invention]

[0023] According to the present invention, even if the chip component is small, it can still be accurately determined whether the chip component is attached to the specified position of the presser. Simple diagram description

[0024] FIG1 is a cross-sectional view illustrating the structure of a presser holding mechanism according to an embodiment of the present invention. Figure 2 is a schematic diagram of the presser holding mechanism of an embodiment of the present invention, (a) is the state observed from the upper side, (b) is the state observed from the lower side without the presser being held, (c) is the state observed from the lower side with the presser close to being present, and (d) is the state observed from the lower side with the presser being held. FIG3 is a cross-sectional view illustrating the structure of the presser holding mechanism according to the embodiment of the present invention, showing an example in which the adsorption portion has a decompression space. FIG. 4 is a diagram showing an embodiment of a presser inspection device using the presser holding mechanism of the present invention. Figure 5(a) shows an example of an image when inspecting a presser for picking up a chip part using a presser inspection device according to an embodiment of the present invention, and Figure 5(b) shows an example of an image when inspecting a presser after installing a chip part using a presser inspection device according to an embodiment of the present invention. FIG. 6 is a diagram showing an example of a method for setting a reference for position information of a chip component within a presser. FIG. 7 is a diagram showing an example of a presser having a presser identification mark. FIG. 8 is a diagram showing an example of a device for obtaining position information of a pressing device identification mark. FIG9 is a diagram showing an example in which adsorption holes of the lower plate of the adsorption portion appear in an image when the presser inspection apparatus according to the embodiment of the present invention is used to inspect a presser that picks up a wafer component. Figure 10 is a schematic diagram of a presser holding mechanism of a variation of an embodiment of the present invention, (a) shows a state where the presser is not held as viewed from the bottom side, and (b) shows a cross-sectional view of an example where the adsorption portion has a decompression space. Figure 11 is a diagram illustrating the operation of the picking device that constitutes the chip transfer device, (a) is a diagram showing the state of the presser approaching the chip part of the transfer source substrate, (b) is a diagram showing the state of the presser in close contact with the chip part, and (c) is a diagram showing the state of the presser picking up the chip part from the transfer source substrate. Figure 12 is a diagram illustrating the operation of the mounting device constituting the chip transfer device, (a) is a diagram showing a state in which a presser holding a chip part is close to a transfer destination substrate, (b) is a diagram showing a state in which the chip part is in close contact with the transfer destination substrate, and (c) is a diagram showing a state in which the presser is moved away after the chip part is mounted on the transfer destination substrate. Figure 13 is a diagram illustrating the status of the presser, (a) is a diagram showing the presser after the picking action, (b) is a diagram showing the presser after the installation action, and (c) is a diagram showing the presser before the picking action and before the installation action. Figure 14 is a cross-sectional view illustrating a defective phenomenon caused by the presser, (a) is a diagram showing a state where the picking action is incomplete, and (b) is a diagram showing a state where the installation action is incomplete. FIG. 15 is a diagram illustrating the inspection of the presser after the picking action and the installation action. FIG. 16 is a diagram showing an apparatus for performing appearance inspection by irradiating light onto the surface of a presser. Figure 17 (a) is a diagram showing an example of an image of the presser surface after picking up, which is obtained by irradiating light onto the presser surface, and (b) is a diagram showing an example of an image of the presser surface after installation, which is obtained by irradiating light onto the presser surface. Implementation Method

[0025] The embodiment of the present invention is described using the drawings. FIG1 is a cross-sectional view of a state in which a presser 2 is held by a presser holding mechanism 1 according to an embodiment of the present invention. FIG2 is a schematic diagram illustrating the shape of the presser holding mechanism 2. FIG2(a) is a view viewed from obliquely above, FIG2(b) is a view viewed from obliquely below in a state in which the presser 2 is not held, FIG2(c) is a state before the presser 2 is held, and FIG2(d) is a state in which the presser is held by adsorption. Furthermore, the connecting portion 31 connects the driving mechanism (not shown) and the presser holding mechanism 1, and is not limited to the shapes shown in FIG1 and FIG2. The presser holding mechanism 1 can be moved up and down or horizontally by the driving mechanism (via the connecting portion 31).

[0026] In this embodiment, the presser body 20 and the adhesive portion 21 constituting the presser 2 are formed of a light-transmitting material. As a specific example, the presser body 20 is glass, quartz, or light-transmitting ceramics, and the adhesive portion 21 is silicone resin.

[0027] The presser holding mechanism 1 has the function of holding the presser 2 from the side opposite to the surface of the presser 2 where the adhesive portion 21 is formed, and irradiating light toward the presser 2. An example thereof is the embodiment shown in FIG. 1 .

[0028] The embodiment of the presser holding mechanism 1 shown in FIG1 is composed of an adsorption portion 11 and an illumination portion 12 overlapping each other. The adsorption portion 11 adsorbs the presser 2 from the side of the presser body 20 opposite to the surface on which the adhesive portion 21 is formed. A adsorption hole 11H is formed on the surface in contact with the presser 2. The adsorption hole 11H is connected to the exhaust hole 11V. The presser 2 can be adsorbed by connecting a pressure reducing mechanism (not shown) to the exhaust hole 11V. In addition, the adsorption portion 11 has light transmittance for irradiating the presser 2 with light emitted from the illumination portion 12. The illumination portion 12 irradiates light to the presser 2 through the adsorption portion 11. It is preferable that the light is evenly irradiated to the entire surface of the presser 2 and is preferably a planar light source. The planar light source mentioned here is not limited to a surface light emitter, but also includes a combination of LEDs and a diffuser plate used in the backlight of an LCD TV. The adsorption portion 11 can be constructed by providing multiple flow paths from the adsorption holes 11H to the exhaust holes 11V within a transparent plate. However, this is not only time-consuming and labor-intensive to manufacture, but also involves light scattering due to the flow paths within the transparent material. Therefore, if the flow paths are not evenly distributed on the front surface, the in-plane distribution of light within the adsorption portion 11 may vary, and the distribution of light directed toward the pressing element 2 may also be uneven, which is unsatisfactory.

[0029] Therefore, the preferred structure for the adsorption unit 11 is as shown in Figure 3 . Specifically, a box is formed by a lower plate 111, an upper plate 112, and side plates 113, forming a reduced-pressure space 110. The lower plate 111 is formed from a light-transmitting plate with adsorption holes 11H, and the upper plate 112 is formed from a light-transmitting plate. This structure allows for a relatively low-cost construction. Furthermore, the lower plate 111 and upper plate 112 can be made of a transparent resin such as acrylic. Glass is ideal for shape stability, and frosted glass is also acceptable for light-transmitting materials. Furthermore, in Figure 3 , the illumination unit 12 is composed of a planar light source, namely a light source 121, and a light source cover 120, which is connected to the adsorption unit 11.

[0030] FIG4 illustrates the configuration of a presser inspection device that uses the presser holding mechanism 1 of the present invention to inspect the state of wafer components attached to presser 2. In FIG4 , the imaging mechanism, namely, camera 4, faces the wafer component holding surface of presser 2, similar to the configuration shown in FIG16 . The image captured by camera 4 is not an image obtained by light reflected from the wafer holding surface of presser 2, but rather an image obtained by light transmitted through presser 2.

[0031] In the case of the presser inspection device shown in FIG4 , light is blocked where wafer components C are present, while light is transmitted through areas where wafer components C are not attached. Consequently, contrast increases depending on the presence or absence of wafer components C. Specifically, in the transmission image captured by camera 4, as shown in FIG5 , ITC, corresponding to the area where wafer components C are attached, becomes darker, while IT21, corresponding to the adhesive portion 21 where wafer components C are not attached, becomes brighter, reaching the same brightness as IT20, corresponding to only the presser body 20.

[0032] Therefore, as shown in Figure 5(a), after the pickup operation and before installation, the difference in brightness between the areas where the wafer component C is not attached is large. By processing the image captured by camera 4 using the image processing mechanism, it is clear that the wafer component C is attached. Furthermore, as shown in Figure 5(b), the presence of the wafer component C remaining on presser 2 is also clearly confirmed by observation after the installation operation.

[0033] Furthermore, there are situations where positional information on the chip components C held by the presser 2 is necessary. In such situations, positional information for each chip component C is obtained using a predetermined position as a reference. Therefore, the predetermined positions may be, for example, positional information for chip components selected from the four outermost corners. However, as shown in Figure 6 , there are situations where no chip components C are held at such locations. Assuming such a situation, using the four corners as an example, positional information for the intersections of several chip components C in the X and Y directions near the four corners can be obtained and used as a reference, as shown in Figure 6 .

[0034] Furthermore, after the mounting operation as shown in Figure 5(b), using a transmission image technique, the brightness of the portion IT21 corresponding to the adhesive portion 21 without the wafer component C attached and the portion IT20 corresponding to only the presser body 20 are equal, making it difficult to obtain contrast and, therefore, difficult to determine a reference. Furthermore, in order to obtain more accurate positional information on each wafer component held by the presser 2, as shown in Figure 7, presser identification marks AS (first presser identification mark AS1 and second presser identification mark AS2) are used, which are protruding shapes and are applied to specific locations on the presser body 20. However, these presser identification marks AS are also difficult to identify in a transmission light image.

[0035] Therefore, when obtaining position information corresponding to the portion of the adhesive portion 21 to which the chip part C is not attached or the presser identification mark AS, it is sometimes ideal to light up the reflection light source 40 in a device structure in which the reflection light source 40 is provided in conjunction with the lighting portion 12 as shown in Figure 8 to obtain a reflection image.

[0036] However, in a configuration where multiple suction holes 11H are formed in the suction portion 11, as in the lower plate 111 in Figure 3 , disadvantages may arise due to the suction holes 11H. For example, as shown in Figure 9 , when comparing the contrast between the portion (ITC) corresponding to the attachment site of the wafer component C, the portion (IT21) corresponding to the adhesive portion 21 to which the wafer component C is not attached, and the portion (IT20) corresponding to only the presser body 20, the portion (IT11H) corresponding to the suction holes 11H may appear, causing interference. Furthermore, if the presser body 20 is attracted to the suction holes 11, causing a dent in the adhesive portion 21, this may hinder the handling of the wafer component C held by the adhesive portion 21.

[0037] To avoid this phenomenon, a modified embodiment of the present invention can be used to adsorb and hold the pressing device 2 on the surface of a porous body. FIG10 shows this example. FIG10(a) shows an example in which a porous region 11P is provided instead of the adsorption holes 11H shown in FIG2(b). FIG10(b) shows an example in which a porous region 11P is provided on the lower plate 111 instead of the adsorption holes 11H shown in FIG3(a).

[0038] By holding the presser 2 by adsorption in the porous region 11P, the obstruction caused by the adsorption holes 11H is improved. However, when the average pore diameter of the porous material increases, the same obstruction as that in the case of providing adsorption holes 11H may occur. Ideally, the average pore diameter is 10 μm or less.

[0039] The porous material is not limited to translucent glass or ceramics; even non-translucent materials such as metals can be used as long as they transmit light through the pores (or reflect light from the inner surface of the pores). Furthermore, if the light reflectivity on the outer surface of the porous material is high, high contrast may not be achieved when detecting the actuator identification mark AS using the reflected image shown in FIG8 , making it difficult to obtain accurate position information. Therefore, the porous material used for the porous region 11P is ideally darker than white (e.g., black). As described above, in the present invention, since transmitted light is used, the light is shielded by the chip component C. On the other hand, the area where the chip component C does not exist can be roughly uniformly bright, and an image with high contrast can be obtained. Therefore, even if the chip component C is small, there is almost no erroneous judgment of whether it is attached or not.

[0040] Therefore, by using the presser inspection device 7 of the present invention to inspect the presser 2 used in the pickup device 5 and the mounting device 6 shown in Figure 15, a chip transfer device with fewer faults can be constructed.

[0041] In addition, if a presser 2 is installed between the presser holding mechanism 1 and the pickup head 101 used by the pickup device 5 or the mounting head 102 used by the mounting device 6, the pickup device 5, the mounting device 6, and the presser inspection device 7 can each operate independently, thereby improving the overall efficiency of the chip transfer device as a device, which is better.

[0042] On the other hand, the pickup head 101 or the mounting head 102 can also be equipped with the function of the presser holding mechanism 1 of the present invention. However, it is difficult for the pickup head 101 to have both the light-emitting function of the presser holding mechanism 1 and the heating function of the mounting device 6. It is relatively easy to have the presser holding mechanism 1.

[0043] 1: Presser holding mechanism 2: Presser 4: Camera 5: Pickup device 6: Install the device 7: Presser inspection device 11: Adsorption part 11H: adsorption hole 11P: Porous area 11V: Exhaust hole 12:Lighting Department 20: Presser body 21: Adhesive part 31: Connection 40: Reflection light source 101: Pickup head 102: Installation head 110: Decompression Space 111: Lower board 112:On the board 113: Side panels 120: Light source cover 121: Light Source AS1: Presser identification mark 1 / Presser identification mark AS2: Presser identification mark 2 / Presser identification mark C: Chip parts IRC: Equivalent to the part that holds the chip parts IT11H: Equivalent to adsorption pores IT20: Equivalent to only the main body of the presser IT21: Equivalent to the adhesive portion where no chip components are attached ITC: Equivalent to the part where the chip parts are attached S0: Transfer source substrate S1: Transfer target substrate X, Y, Z: direction

Claims

1. A press holding mechanism for holding a press, wherein the press is used to transfer wafer components located on a transfer source substrate to a transfer destination substrate by simultaneously attaching a plurality of wafer components using adhesiveness, the press holding mechanism comprising: an adsorption portion having the function of adsorbing and holding the side opposite to the adhesive side of the press, and having light transmittance; and an illumination portion disposed on the side opposite to the adsorption side of the adsorption portion that adsorbs the press, irradiating the press with light through the adsorption portion.

2. The presser holding mechanism of claim 1, wherein the aforementioned adsorption part comprises: a lower plate, which is composed of a light-transmitting plate provided with adsorption holes; an upper plate, which is light-transmitting; and a side plate; the aforementioned adsorption part is configured to form a pressure-reducing space inside.

3. The press holding mechanism of claim 1, wherein the aforementioned adsorption part has a porous region, and the aforementioned porous region tightly adsorbs and holds the aforementioned press.

4. A presser inspection apparatus for inspecting a presser with a wafer component attached thereto, wherein the presser uses adhesiveness to simultaneously attach a plurality of the wafer components to transfer the wafer components located on a transfer source substrate to a transfer destination substrate, and the presser inspection apparatus comprises: a presser holding mechanism that holds the side opposite to the adhesive side of the presser and illuminates the presser with light; and a camera mechanism that acquires an image through the presser while the presser is illuminated with light.

5. The presser inspection device as claimed in claim 4, further comprising: an image processing mechanism that determines, based on an image obtained by the aforementioned camera mechanism, whether a chip component is attached to a specified location of the aforementioned presser.

6. A wafer transfer apparatus comprising: a presser inspection device as claimed in claim 4 or 5; a pick-up device that simultaneously picks up a plurality of wafer components from the aforementioned transfer source substrate using the presser; and a mounting device that simultaneously mounts the plurality of wafer components onto the aforementioned transfer destination substrate using the presser.

7. The wafer transfer apparatus of claim 6, which has the function of checking the presser after a pickup action has been performed in the pickup device by the aforementioned presser inspection device, and the function of checking the presser after an installation action has been performed in the aforementioned mounting device by the aforementioned presser inspection device.

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