Stamp holding means, stamp inspection device using the same, and chip transfer device

Abstract

To provide stamp holding means used to accurately inspect whether chip components are adhered to predetermined locations on a stamp, even if the chip components are small, and a stamp inspection apparatus and a chip transfer apparatus using the same.SOLUTION: Stamp holding means that holds a stamp, uses adhesiveness to simultaneously adhere multiple chip components to transfer chip components on the source substrate to the destination substrate, and holds the opposite side of the adhesive side of the stamp to irradiate the stamp with light.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to stamp holding means for holding a stamp used when picking up a chip component from a transfer source substrate and transferring it to a transfer destination substrate, and to a stamp inspection device and a chip transfer device using the same. [Background technology]

[0002] As μLED displays become more widely used, there has been growing interest in chip transfer devices that pick up densely packed chip components on a source substrate, widen the pitch, and mount them on a destination substrate.

[0003] As such a chip transfer device, a method using a chip stamp that simultaneously attaches and detaches multiple chip components to and from an adhesive surface is known (see, for example, Patent Document 1). As shown in the cross-sectional view of Figure 11(a), the stamp 2 has adhesive portions 21 provided on a plate-shaped stamp body 20, and the spacing between the adhesive portions 21 is an integer multiple of the pitch of the chip components C on the source substrate S0.

[0004] As shown in Fig. 11(a), the stamp 2 held by the pick-up head 101 is aligned so that the chip component C is placed directly under the adhesive portion 21, and then the adhesive portion 21 is brought into close contact with the chip component C as shown in Fig. 11(b). At this stage, if the adhesive force of the adhesive portion 21 to the chip component C is greater than the adhesive force to the source substrate S0, the stamp 2 is raised (moved away from the source substrate S0), and the chip component C that is in close contact with the adhesive portion 21 is picked up from the source substrate S0 (Fig. 11(c)).

[0005] The stamp 2 that has picked up the chip component C is held by the mounting head 102, and after being aligned with a predetermined position on the destination substrate S1 as shown in FIG. 12(a), it is pressed onto the destination substrate S1 as shown in FIG. 12(b). At this stage, if the adhesive strength of the adhesive portion 21 to the chip component C is weakened by heating or the like to be weaker than the bonding strength to the destination substrate S1, then when the stamp 2 is raised (moved away from the destination substrate S1), the chip component C will be separated from the stamp 2 and mounted on the destination substrate S1 (FIG. 12(c)). Here, the chip component C may be heated to weaken the adhesive strength of the adhesive portion 21 while strengthening the bonding strength between the chip component C and the destination substrate S1.

[0006] As described above, the stamp 2 transfers the chip component C picked up from the source substrate S0 to the destination substrate S1 with the chip component C attached to the adhesive portion 21 as shown in Fig. 13(a), and after transfer, as shown in Fig. 13(b), the chip component C is not attached to the adhesive portion 21. Fig. 13(c) shows the configuration of a chip transfer device that performs such operations, and is equipped with a pickup device 5 and a mounting device 6.

[0007] In such a chip transfer device, chip components C should be held on all adhesive portions 21 in the pickup device 5, and all chip components C attached to the adhesive portions 21 should be transferred to the destination substrate S1 in the mounting device 6. However, in the pickup device 5, chip components C may not be attached to some of the adhesive portions 21 as shown in Figure 14(a). Also, in the mounting device 6, chip components C that could not be mounted on the destination substrate S1 may remain on the adhesive portions 21 as shown in Figure 14(b).

[0008] 14(a) and 14(b) would be a major problem in the chip transfer process, so it is preferable to place a stamp inspection device 7 between the pickup device 5 and the mounting device 6. The stamp inspection device 7 checks whether or not a chip component C is attached to a predetermined location (adhesive portion 21) of the stamp 2 in the state of FIG. 13(a), and inspects whether or not any chip component C remains on the stamp 2 in the state of FIG. 13(b).

[0009] Fig. 16 shows a configuration using a typical appearance inspection device for observing the state of the chip component holding surface of stamp 2. In Fig. 16, the chip component holding surface of stamp 2 illuminated by light emitted by reflective light source 40 is photographed by camera 4, which is an imaging means, and the image is analyzed to determine whether or not chip components C are attached. For example, Fig. 17(a) shows the state of the chip component holding surface after pick-up and before mounting, where the IRC corresponding to the portion holding chip components C is bright and the portion corresponding to adhesive portion 21 not holding chip components C is dark. Fig. 17(b) shows the state of the chip component holding surface after mounting, and it can be seen that chip components C remain in the bright portion. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Publication No. 2019-175961 Summary of the Invention [Problem to be solved by the invention]

[0011] When performing inspection with the configuration shown in Figure 16, the state of the reflected image varies depending on the light intensity and direction of the reflection light source 40, and if you try to determine the presence or absence of a chip component C based on the brightness of the image, it is difficult to set a threshold value, which may result in an erroneous judgment.

[0012] In particular, as chip components C become smaller and the number of chip components C attached to one stamp 2 increases, the number of pixels of the camera 4 for each chip component C decreases, making accurate determination difficult.

[0013] The present invention has been made in consideration of the above problems, and provides a stamp holding means used to accurately inspect whether or not a chip component is attached to a specified location on a stamp, even if the chip component is small, as well as a stamp inspection device and a chip transfer device using the same. [Means for solving the problem]

[0014] In order to solve the above problem, the invention of claim 1 is as follows: A stamp holding means for holding a stamp, The stamp uses its adhesiveness to simultaneously attach multiple chip components, transferring the chip components on the source substrate to the destination substrate. A stamp holding means holds the side of the stamp opposite to the adhesive surface and irradiates the stamp with light.

[0015] The invention described in claim 2 is the stamp holding means described in claim 1, a light-transmitting adsorption portion that adsorbs and holds the opposite side of the stamp's adhesive surface; The stamp holding means includes an illumination unit that is disposed on the opposite side of the surface of the adsorption unit that adsorbs the stamp, and that irradiates light onto the stamp through the adsorption unit.

[0016] The invention described in claim 3 is the stamp holding means described in claim 2, The suction unit is a stamp holding means having a translucent lower plate with suction holes, a translucent upper plate, and side plates, and is configured to form a reduced pressure space inside.

[0017] The invention described in claim 4 is the stamp holding means described in claim 2, The adsorption portion is a stamp holding means having a porous region, and the porous region adheres closely to the stamp to adsorb and hold the stamp.

[0018] The invention described in claim 5 is a stamp inspection device comprising a stamp holding means described in any one of claims 1 to 4 and an imaging means for acquiring an image transmitted through the stamp while irradiating the stamp with light.

[0019] The invention described in claim 6 is the stamp inspection device described in claim 5, The stamp inspection device further comprises image processing means for determining whether or not a chip component is attached to a predetermined location on the stamp from the image acquired by the imaging means.

[0020] The invention described in claim 7 is a pickup device that uses the stamp to simultaneously pick up a plurality of chip components on the transfer source substrate; a mounting device that simultaneously mounts a plurality of chip components on the destination substrate; A chip transfer device comprising the stamp inspection device according to claim 5 or 6.

[0021] The invention described in claim 8 is the chip transfer device described in claim 7, This is a chip transfer device that has a function in which the stamp inspection device inspects the stamp after the pickup operation has been performed by the pickup device, and a function in which the stamp inspection device inspects the stamp after the mounting operation has been performed by the mounting device. [Effects of the Invention]

[0022] According to the present invention, it is possible to accurately determine whether or not a chip component is attached to a predetermined location on a stamp, even if the chip component is small. [Brief explanation of the drawings]

[0023] [Figure 1] 3 is a cross-sectional view illustrating the configuration of a stamp holding means according to the embodiment of the present invention. FIG. [Figure 2] 1A and 1B are schematic diagrams of a stamp holding means according to an embodiment of the present invention, showing (a) a state seen from above, (b) a state where no stamp is being held as seen from below, (c) a state where the stamp is approaching as seen from below, and (d) a state where a stamp is being held as seen from below. [Figure 3] FIG. 2 is a cross-sectional view illustrating the configuration of a stamp holding means according to an embodiment of the present invention, showing an example in which an adsorption part has a reduced pressure space. [Figure 4]1 is a diagram showing an embodiment of a stamp inspection device using a stamp holding means of the present invention. [Figure 5] 1A shows an example of an image when inspecting a stamp that has picked up a chip component, and FIG. 1B shows an example of an image when inspecting a stamp after mounting a chip component, using a stamp inspection device according to an embodiment of the present invention. [Figure 6] 10A and 10B are diagrams showing an example of a method for setting a reference for position information of a chip component in a stamp. [Figure 7] FIG. 10 is a diagram showing an example of a stamp having a stamp recognition mark. [Figure 8] FIG. 10 is a diagram illustrating an example of a device configuration for acquiring position information of a stamp recognition mark. [Figure 9] 10 is a diagram showing an example of an image obtained when inspecting a stamp that has picked up a chip component using a stamp inspection device according to an embodiment of the present invention, in which a suction hole in a lower plate of the suction part is reflected. FIG. [Figure 10] 1A and 1B are schematic diagrams of a stamp holding means according to a modified embodiment of the present invention, in which (a) shows a state in which the stamp is not held as viewed from below, and (b) shows a cross-sectional view of an example in which the suction part has a reduced pressure space. [Figure 11] This explains the operation of the pickup device that constitutes the chip transfer device, and shows (a) a state in which the stamp is approaching the chip component on the transfer source substrate, (b) a state in which the stamp is in close contact with the chip component, and (c) a state in which the stamp has picked up the chip component from the transfer source substrate. [Figure 12] This explains the operation of the mounting device that constitutes the chip transfer device, and shows (a) a state in which a stamp holding a chip component is approaching a destination substrate, (b) a state in which the chip component is in close contact with the destination substrate, and (c) a state in which the stamp moves away after mounting the chip component on the destination substrate. [Figure 13] 1A and 1B are diagrams illustrating the state of the stamp, showing (a) the stamp after the pick-up operation, (b) the stamp after the mounting operation, and (c) the stamp before the pick-up operation and before the mounting operation. [Figure 14]1A and 1B are cross-sectional views illustrating a defect phenomenon that occurs in a stamp, showing a state in which the pick-up operation is incomplete and a state in which the mounting operation is incomplete. [Figure 15] 10A and 10B are diagrams illustrating stamp inspection after a pick-up operation and after a mounting operation. [Figure 16] FIG. 1 is a diagram showing a configuration of an apparatus for performing an appearance inspection by irradiating light onto the surface of a stamp. [Figure 17] 1A and 1B are diagrams showing an example of an image of the stamp surface after picking up, and an example of an image of the stamp surface after mounting, both obtained by irradiating the stamp surface with light. DETAILED DESCRIPTION OF THE INVENTION

[0024] An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a stamp holding means 1 in an embodiment of the present invention holding a stamp 2. FIG. 2 is a schematic diagram illustrating the shape of the stamp holding means 2, with FIG. 2(a) being a view from diagonally above, FIG. 2(b) being a view from diagonally below showing the stamp 2 not being held, FIG. 2(c) being a view before the stamp 2 is held, and FIG. 2(d) being a view holding the stamp by suction. Note that the connecting portion 31 connects the stamp holding means 1 to a drive mechanism (not shown), and is not limited to the shape shown in FIGS. 1 and 2; the stamp holding means 1 can be moved up and down and horizontally by the drive mechanism (via the connecting portion 31).

[0025] In this embodiment, the stamp body 20 and adhesive portion 21 that constitute the stamp 2 are formed from a translucent material, and as a specific example, the stamp body 20 is glass, quartz, or translucent ceramics, and the adhesive portion 21 is silicone resin.

[0026] The stamp holding means 1 has the function of holding the stamp 2 from the side opposite to the surface on which the adhesive portion 21 of the stamp 2 is formed, and irradiating the stamp 2 with light, an example of which is the embodiment shown in FIG.

[0027] The stamp holding means 1 of the embodiment shown in FIG. 1 is configured by stacking an adsorption section 11 and an illumination section 12. The adsorption section 11 adsorbs the stamp 2 from the side opposite to the side on which the adhesive section 21 of the stamp body 20 is formed. Adsorption holes 11H are formed on the surface that contacts the stamp 2, and the adsorption holes 11H are connected to exhaust holes 11V. The stamp 2 can be adsorbed by connecting a pressure reducing means (not shown) to the exhaust holes 11V. The adsorption section 11 is also translucent so that light emitted from the illumination section 12 can be irradiated onto the stamp 2. The illumination section 12 irradiates the stamp 2 with light through the adsorption section 11, but it is preferable that the light be irradiated evenly over the entire surface of the stamp 2, and is preferably a planar light source. The planar light source referred to here is not limited to a surface light emitter, but also includes a combination of an LED and a diffuser, such as that used in the backlight of an LCD television. Although the suction unit 11 may be configured to have many flow paths from the suction holes 11H to the exhaust holes 11V in a transparent plate-like material, this requires time and effort to process, and the flow paths in the transparent material scatter light. Therefore, if the flow paths are not evenly distributed on the front surface, the in-plane distribution of light within the suction unit 11 may change, resulting in a bias in the distribution of light irradiated onto the stamp 2, which is not desirable.

[0028] Therefore, it is preferable to configure the suction unit 11 as shown in FIG. 3. That is, a box is formed by a lower plate 111 made of a translucent plate with suction holes 11H, and an upper plate 112 and side plates 113 also made of translucent plates, forming a reduced pressure space 110. This structure can be constructed relatively inexpensively. The material of the lower plate 111 and the upper plate 112 may be a transparent resin such as acrylic, but glass is preferable in consideration of shape stability, and frosted glass may also be used as long as it is translucent. In addition, in FIG. 3, the illumination unit 12 is composed of a light source 121, which is a surface light source, and a light source cover 120, and the light source cover 120 is connected to the suction unit 11.

[0029] Fig. 4 shows the configuration of a stamp inspection device that uses the stamp holding means 1 of the present invention to inspect the state in which chip components are attached to a stamp 2. In Fig. 4, the camera 4, which is the imaging means, is directed toward the chip component holding surface of the stamp 2, just as in Fig. 16, but what the camera 4 captures is not an image obtained by light reflected from the chip holding surface of the stamp 2, but an image obtained by light that passes through the stamp 2.

[0030] In the stamp inspection device shown in Fig. 4, light is blocked where chip components C are present, while light is transmitted where chip components C are not attached, resulting in a greater contrast depending on the presence or absence of chip components C. That is, in the transmission image captured by camera 4, as shown in Fig. 5, ITC in the portion corresponding to the portion where chip components C are attached is dark, and IT21 in the portion corresponding to adhesive portion 21 where chip components C are not attached is bright, so that IT21 has the same brightness as IT20 corresponding to only stamp body 20.

[0031] 5(a), when observed after the pick-up operation and before mounting, there is a large difference in brightness between areas where no chip components C are attached, and when the image captured by the camera 4 is processed by image processing means, it is clearly apparent that there are chip components C attached. Also, as shown in FIG. 5(b), when observed after the mounting operation, the presence of chip components C remaining on the stamp 2 is clearly apparent.

[0032] There may be cases where positional information on chip components C on stamp 2 is required. In such cases, the positional information of each chip component C is obtained using a predetermined position as a reference. For example, the predetermined position may be the positional information of a chip component selected from the four outermost corners. However, as shown in Figure 6, there may be cases where no chip component C is held in the relevant location. In anticipation of such a situation, taking the four corners as an example, the positional information of the intersections of several chip components C in each of the X and Y directions near the four corners may be obtained and used as a reference, as shown in Figure 6.

[0033] 5(b), in the method using a transmitted light image, it is difficult to obtain a reference because the portion IT21 corresponding to the adhesive portion 21 to which the chip component C is not attached and the portion IT20 corresponding to only the stamp body 20 have the same brightness, making it difficult to obtain contrast. Furthermore, in order to obtain the positional information of each chip component held on the stamp 2 with even higher precision, as shown in FIG. 7, stamp recognition marks AS (first stamp recognition mark AS1, second stamp recognition mark AS2) with protrusions formed in predetermined locations on the stamp body 20 are used, but these stamp recognition marks AS are also difficult to recognize in a transmitted light image.

[0034] Therefore, when obtaining position information of the portion corresponding to the adhesive portion 21 to which the chip component C is not attached or the stamp recognition mark AS, it may be desirable to obtain a reflected image by turning on the reflection light source 40 while turning off the illumination unit 12 in an apparatus configuration as shown in Figure 8, which also includes a reflection light source 40.

[0035] 3, in a configuration in which a plurality of suction holes 11H are formed in the suction portion 11, the suction holes 11H can cause problems. One such problem is that, as shown in FIG. 9, when comparing the contrast between the ITC in the portion corresponding to the location where the chip component C is attached, the IT21 in the portion corresponding to the adhesive portion 21 where no chip component C is attached, and the IT20 in the portion corresponding to only the stamp body 20, the IT11H corresponding to the suction holes 11H may be reflected and cause disturbance. Furthermore, if the stamp body 20 is sucked into the suction holes 11H and a dent is formed in the adhesive portion 21, handling of the chip component C held by the adhesive portion 21 may be hindered.

[0036] To avoid this phenomenon, as a modified example of the embodiment of the present invention, the stamp 2 may be held by suction on the surface of a porous body, an example of which is shown in Figure 10. Figure 10(a) shows an example in which a porous region 11P is provided instead of the suction holes 11H shown in Figure 2(b). Figure 10(b) shows an example in which a porous region 11P is provided in the lower plate 111 of Figure 3(a) instead of the suction holes 11H.

[0037] By suction-holding the stamp 2 in the porous region 11P, the problems caused by the suction holes 11H are alleviated. However, if the average pore size of the porous region becomes too large, problems similar to those caused by the suction holes 11H may occur, and therefore it is desirable that the average pore size be 10 μm or less.

[0038] The porous material is not limited to translucent glass or ceramics; non-translucent materials made of metal can also be used as long as they transmit light through the holes (or reflect light from the inner surfaces of the holes). Furthermore, if the light reflectance of the outside of the porous material is high, it may be difficult to obtain high contrast and accurate position information when detecting the stamp recognition mark AS using the reflected image shown in Figure 8. For this reason, it is desirable that the appearance of the porous material used in the porous region 11P be a darker color (such as black) than white. As described above, in the present invention, transmitted light is used, and while light is blocked by chip components C, areas where chip components C are not present are almost uniformly bright, and an image with high contrast is obtained, so there is almost no chance of erroneously determining whether or not chip components C are attached, even when the chip components C are small.

[0039] Therefore, by using the stamp inspection device 7 of the present invention to inspect the stamp 2 used in the pickup device 5 and mounting device 6 shown in FIG. 15, a chip transfer device with fewer problems can be configured.

[0040] Incidentally, if the stamp 2 is switched between the stamp holding means 1 and the pickup head 101 used in the pickup device 5 or the mounting head 102 used in the mounting device 6, the pickup device 5, the mounting device 6, and the stamp inspection device 7 can each be operated independently, which is preferable as it increases the efficiency of the chip transfer device as a whole.

[0041] On the other hand, the function of the stamp holding means 1 of the present invention may be provided in the pickup head 101 or the mounting head 102. However, it is difficult to provide both the light emitting function of the stamp holding means 1 and the heating function of the mounting device 6, but it is relatively easy for the pickup head 101 to provide the stamp holding means 1. [Explanation of symbols]

[0042] 1. Stamp holding means 2. Stamps 4. Camera 5 Pickup device 6 Mounting equipment 7 Stamp inspection equipment 11 Adsorption part 11H Adsorption hole 11P porous area 11V exhaust hole 12 Lighting Department 20 Stamp body 21 Adhesive part 31 Connecting part 40 Reflection light source 101 Pickup head 102 Mounting head 110 Decompressed Space 111 Lower plate 112 Upper Plate 113 Side wall 120 Light source cover 121 Light source AS1, AS2 stamp recognition mark C Chip parts S0 Original substrate S1 Destination substrate

Claims

1. A stamp inspection device that inspects the state of attachment of chip components to a stamp, The stamp uses its adhesiveness to simultaneously attach multiple chip components, transferring the chip components on the source substrate to the destination substrate. a stamp holding means for holding the side opposite to the adhesive surface of the stamp and irradiating the stamp with light; and an imaging means for capturing an image transmitted through the stamp while irradiating the stamp with light.

2. The stamp inspection device according to claim 1, The stamp inspection device further comprises image processing means for determining whether or not a chip component is attached to a predetermined location on the stamp from the image acquired by the imaging means.

3. The stamp inspection device according to claim 1, The stamp holding means a light-transmitting adsorption portion that adsorbs and holds the opposite side of the stamp's adhesive surface; a lighting unit disposed on the opposite side of the adsorption unit from the surface that adsorbs the stamp, and that irradiates light onto the stamp through the adsorption unit.

4. The stamp inspection device according to claim 3, The stamp inspection device is characterized in that the suction unit has a lower plate made of a translucent plate with suction holes, an upper plate that is also translucent, and side plates, and is configured so that a reduced pressure space can be formed inside.

5. The stamp inspection device according to claim 3, The stamp inspection device is characterized in that the suction portion has a porous region, and the porous region adheres closely to the stamp and holds it by suction.

6. a pickup device that uses the stamp to simultaneously pick up a plurality of chip components on the transfer source substrate; a mounting device that uses the stamp to simultaneously mount a plurality of chip components on the destination substrate; A chip transfer device comprising the stamp inspection device according to claim 1 or 2.

7. 7. The chip transfer device according to claim 6, a function of inspecting the stamp after the pick-up operation is performed by the pick-up device using the stamp inspection device; and a stamp inspection device that inspects the stamp after the mounting operation has been performed by the mounting device.

Images