TWI716977B - Transfer stamp - Google Patents

Abstract

A transfer stamp includes a substrate and a plurality of posts. The substrate has a transfer area and a frame area surrounding the transfer area. The posts are disposed on the transfer area. The frame area includes a plurality of trenches. The substrate includes a top surface and a bottom surface opposite to the top surface. The trenches extend from the top surface into the substrate. The trenches surround the transfer area.

Description

Transposed head

This disclosure is about a transposed head.

Miniature light-emitting diodes have the advantages of miniaturization, lightness and thinness, self-luminescence, high brightness and high contrast. The micro light emitting diode display includes a plurality of light emitting diodes and a driving circuit substrate. In the manufacturing process of the micro light emitting diode display, a plurality of micro light emitting diodes are first formed on the growth substrate, and then the micro light emitting diode can be transferred from the growth substrate to the driving circuit substrate by the mass transfer technology. The transfer technology can pick up and place miniature light-emitting diodes through the flexible transposing head, however. Generally speaking, the manufacturing method of the elastic transposition head is to pour the polymer material into a mold, and the polymer material is cured and then demolded to obtain the elastic transposition head.

During demolding, the elastic transposition head may be deformed unavoidably due to the properties of polymer materials. One of the traditional solutions is to raise the transposition head to contact the transposition area of the micro-components. The heightening method is for example double coating The method forms the platform area below it, and then cures it in an oven. However, during the curing process, air may not be completely exhausted to form bubbles, resulting in small holes in or on the surface of the platform area after molding, which affects the transposition yield of the micro light emitting diodes in the transposed area.

The present disclosure provides a transposing head, which can ensure the transposing yield of the micro light emitting diode by the transposing area.

The transposed head of the present disclosure includes a substrate and a plurality of bumps. The substrate defines a transposed area and a frame area surrounding the transposed area. The bump is arranged on the transposed area. The frame area includes a plurality of grooves. The substrate has opposite top and bottom surfaces, the groove extends from the top surface into the substrate, and the groove surrounds the transposed area.

Based on the above, in the transposition head proposed in the present invention, through the frame area with multiple grooves, and the grooves surround the transposition area, during demolding, the demolding point between the frame area and the mold can be increased ( peeling point), which makes the frame area and the mold form a discontinuous stripping line during the stripping process, suppresses the warping of the top surface of the frame area and reduces the edge deformation of the transposed area, thereby ensuring that the transposed area is opposite to the micro light emitting diode The transposition yield rate. Among them, the application of this kind of transposed head is not limited to the transposition of miniature light-emitting diodes, and can also be used in transposition and applications of other semiconductor devices.

10, 10a, 10b, 10c, 10d‧‧‧Transposed head

100‧‧‧Substrate

100A‧‧‧Top surface

100B‧‧‧Bottom

102‧‧‧ bump

104‧‧‧Groove

104a‧‧‧Groove

104b‧‧‧Groove

104c‧‧‧Groove

104d‧‧‧Groove

Section A-A’‧‧‧

Section B-B’‧‧‧

D1‧‧‧direction

D2‧‧‧direction

D3‧‧‧direction

E1‧‧‧First endpoint

E2‧‧‧second endpoint

FA‧‧‧Frame Area

H‧‧‧depth

L‧‧‧Maximum length

PA‧‧‧Transpose area

S‧‧‧Pitch

T‧‧‧Thickness

Read the following detailed description and match the corresponding drawings to understand many aspects of this disclosure. It should be noted that many of the features in the drawing are not drawn in actual proportions according to the standard practice in the industry. In fact, the size of the feature can be increased or decreased arbitrarily to facilitate the clarity of the discussion.

FIG. 1A is a schematic top view of a transposition head according to an embodiment of the disclosure.

Figure 1B is a schematic cross-sectional view of Figure 1A along the section line A-A'.

Figure 1C is the top surface of the frame area measured from the edge of the transposed area to the frame area Comparison chart of warpage.

2A to 2C are schematic top views of a transposition head according to another embodiment of the disclosure.

3A and 3B are schematic top views of a transposition head according to another embodiment of the disclosure.

FIG. 4 is a schematic top view of a transposition head according to another embodiment of the disclosure.

FIG. 5A is a schematic top view of a transposition head according to another embodiment of the disclosure.

Figure 5B is a schematic cross-sectional view of Figure 5A along the section line B-B'.

6A to 6D are schematic top views of a transposition head according to another embodiment of the disclosure.

7A to 7F show schematic cross-sectional views of the groove of the transposition head in FIG. 6A.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

FIG. 1A is a schematic top view of a transfer stamp 10 according to an embodiment of the disclosure. Figure 1B is a schematic cross-sectional view of Figure 1A along the section line A-A'. Referring to FIGS. 1A and 1B at the same time, the transposition head 10 of the embodiment of the disclosure includes a substrate 100 and a plurality of bumps 102. The substrate 100 has a top surface 100A and a bottom surface 100B opposed to each other. The substrate 100 defines a post area PA and a frame area FA. The frame area FA surrounds the transposed area PA, and the bumps 102 are disposed on the transposed area. Area PA, so the transposed area PA is also called convex Block area. In this embodiment, the transposing head 10 is used to transpose a miniature light emitting diode to manufacture a display device as an example. In other embodiments, it can also be used to transpose other semiconductor components. In this embodiment, the material of the transposition head 10 is, for example, polydimethylsiloxane (PDMS), but the disclosure is not limited to this. In other embodiments, the transposition head 10 can be Young's modulus (Young's modulus) elastomer. The material of the bump 102 is, for example, an insulating material, such as an inorganic material, an organic material, a combination of the foregoing, or a stacked layer thereof.

FIG. 1A also shows an enlarged schematic diagram of the bump 102. The bump 102 is used to contact the target micro-light-emitting diode to extract multiple target micro-light-emitting diodes. The manufacturing method of the transposing head 10 is, for example, pouring the polymer material into a mold, and then demolding the polymer material after curing, thereby obtaining the transposing head 10, wherein the top surface 100A of the substrate 100 can be regarded as the contact of the transposing head 10 The face of the mold. In this embodiment, the frame area FA includes a plurality of grooves 104, where the grooves 104 can be used as demolding points. The trench 104 extends from the top surface 100A into the substrate 100, and the trench 104 surrounds the transposition area PA. As a result, the frame area FA has a plurality of grooves 104. During demolding, the release point of the interface between the frame area FA and the mold can be increased, so that the frame area FA and the mold form a discontinuous release line when the mold is released. Therefore, the top surface 100A of the substrate 100 in the frame area FA is prevented from warpage and edge deformation, thereby ensuring the transposition yield of the transposition area PA.

In this embodiment, the top-view shape of the trench 104 is a square. The contour shape of the arrangement of the trenches 104 is substantially the same as the contour shape of the transposed area PA. The trench 104 is point-symmetric with respect to the transposed area PA. The symmetrical grooves of this solution are used to balance the release stress in various directions during the release, and increase the area utilization rate of the top surface 100A of the substrate 100. That is, the substrate 100 located in the frame can be more effectively used The top surface 100A of the area FA is equipped with more grooves 104, so as to increase the release point of the interface between the frame area FA and the mold, so that the frame area FA and the mold form a discontinuous release line when the mold is released. The top surface 100A of the substrate 100 located in the frame area FA is prevented from warpage and edge deformation, thereby ensuring the transposition yield of the transposition area PA.

As illustrated by FIG. 1C, the groove 104 of the frame area FA extends from the top surface 100A into the substrate 100 and the groove 104 surrounds the transposition area PA, which can prevent the substrate 100 from warping and deforming on the top surface 100A of the frame area FA. .

FIG. 1C is a comparison diagram of the warpage of the substrate 100 on the top surface 100A of the frame area FA measured from the edge of the transposed area PA to the edge of the frame area FA. The curve 1000 represents the warping result of the top surface 100A in FIG. 1A, and the frame area FA in FIG. 1A includes a plurality of grooves 104. Assuming that the transposed head 10 without the groove 104 is a comparative example (hereinafter referred to as "comparative example 1"), the curve 1002 represents the warpage result of the top surface 100A of the comparative example 1. Like the curve 1000 shown in FIG. 1C, the warping height of the frame area FA in FIG. 1A at a position about 8 mm from the edge of the transposed area PA is about 4 microns. As shown in the curve 1002 in Fig. 1C, the warping height of the frame area FA of the comparative example 1 from the edge of the transposed area PA is about 18 microns. It can be seen that the degree of warping of the frame area FA of the comparative example 1 The degree of warpage is greater than that of the frame area FA in Figure 1A. This result confirms that the transposition head 10 of the present disclosure can indeed extend from the top surface 100A into the substrate 100 by providing the groove 104 and the groove 104 surrounds the transposition area PA to prevent the substrate 100 from being located on the top surface 100A of the frame area FA. Warping occurs and the edge is deformed, thereby ensuring the transposition yield of the transposition area PA, and achieving the effect of improving the reliability of the transposing head 10.

In addition, although Figure 1A shows that the top view shape of the trench 104 is positive Square, but the invention is not limited to this. In other embodiments, the top-view shape of the groove 104 may also be a circle (as shown in Figure 2A), a triangle (as shown in Figure 2B), or a diamond (as shown in Figure 2C).

3A and 3B are schematic top views of a transposition head 10a according to another embodiment of the disclosure. The transposition head 10a of FIG. 3A is similar to the transposition head 10 of FIG. 1A. Therefore, only the main differences between each other will be described below.

Please refer to Figure 3A, the top view of the transposed head 10a is a square, and there is a gap S between the grooves 104a. The ratio of the maximum length L of the groove 104a to the gap S is approximately in the range of 1/5000 to 5000. In an embodiment where the top-view shape of the groove 104a is circular, the maximum length L of the groove 104a is equal to the diameter of the groove 104a. In this way, the groove 104a can effectively provide the effect of suppressing warpage and edge deformation of the top surface 100A of the substrate 100 located in the frame area FA, thereby ensuring the transposition yield of the transposition area PA. In addition, although FIG. 3A shows that the top-view shape of the trench 104a is circular, the present invention is not limited to this. In other embodiments, the top view shape of the trench 104a may also be a square (as shown in FIG. 3B).

FIG. 4 is a schematic top view of a transposition head 10b according to another embodiment of the disclosure. The transposition head 10b of Fig. 4 is similar to the transposition head 10 of Fig. 1A. Therefore, only the main differences between each other will be described below.

Referring to FIG. 4, the trench 104b extends from the edge of the transposed area PA to the edge of the substrate 100. The trench 104b has a first end E1 and a second end E2 opposite to each other. The second end E2 is greater than the first end E1 is farther away from the bump 102, the ratio of the number of grooves 104b to the length of the line of the second end E2 is approximately in the range of 0.1/mm to 100/mm, and the second end E2 is located on the substrate 100 Therefore, it can also be considered that the ratio of the number of grooves 104b to the circumference of the substrate 100 is about 0.1 In the range of pieces/mm to 100 pieces/mm. In this way, the groove 104b can effectively provide the effect of suppressing warpage and edge deformation of the top surface 100A of the substrate 100 in the frame area FA, thereby ensuring the transposition yield of the transposition area PA.

FIG. 5A is a schematic top view of a transposition head 10c according to another embodiment of the disclosure. Figure 5B is a schematic cross-sectional view of Figure 5A along the section line B-B'. The transposition head 10c of FIG. 5A is similar to the transposition head 10 of FIG. 1A. Therefore, only the main differences between each other will be described below.

Please refer to FIGS. 5A and 5B at the same time. The top view of the groove 104c is annular and concentric with the transposed area PA as the center. The ratio of the number of grooves 104c to the maximum radius R of groove 104c is approximately In the range of 0.1 pcs/mm to 100 pcs/mm. In this way, the trench 104c can effectively provide the effect of suppressing warpage and edge deformation of the top surface 100A of the substrate 100 located in the frame area FA, thereby ensuring the transposition yield of the transposition area PA. The depth H of the groove 104c gradually becomes smaller from the edge of the transposition area PA toward the edge of the substrate 100, thereby improving the ease of demolding of the transposition head 10c and avoiding deformation of the frame area FA.

6A to 6D are schematic top views of a transposition head 10d according to another embodiment of the disclosure. The transposition head 10d of Fig. 6A is similar to the transposition head 10 of Fig. 1A. Therefore, only the main differences between each other will be described below.

Referring to FIG. 6A, the groove 104d extends from the edge of the transposed area PA to the edge of the substrate 100, the frame area FA has a first area in the orthographic projection of the substrate 100, and the sum of the orthographic projection of the groove 104d on the substrate 100 has a second area. Area, the ratio of the second area to the first area is about 1x10 ^-7 to 0.75. The groove 104d extends along the direction D1 and the direction D2 to the edge of the substrate 100, and the direction D1 and the direction D2 intersect. In this way, by demolding the transposed head 10d along the direction D1 and the direction D2, the demolding can be achieved. The ease is improved, and the top surface 100A of the substrate 100 in the frame area FA is prevented from warping and edge deformation. When the translating head 10d transposes the target micro light emitting diode (not shown) on the receiving substrate (not shown), and then separating it from the target micro light emitting diode, leaving the target micro light emitting diode on the receiving substrate By separating the transposing head 10d from the target micro light-emitting diode along the direction D1 and the direction D2, the transposition efficiency can be improved. In this embodiment, the direction D1 and the direction D2 are substantially perpendicular, but the disclosure is not limited thereto.

In other embodiments, the trench 104d only extends along the direction D3 (see FIG. 6B). By demolding the transposed head 10d along the direction D3, the ease of demolding is improved, and the top surface 100A of the substrate 100 in the frame area FA is prevented from warping and edge deformation. In this embodiment, the direction D3 is different from the directions D1 and D2, but the disclosure is not limited thereto.

In addition, although FIG. 6B illustrates that the top-view shape of the trench 104d is linear, the disclosure is not limited to this. In other embodiments, the top-view shape of the groove 104d may also be a wave shape (as shown in Figure 6C) or a continuously arranged diamond shape (as shown in Figure 6D).

Fig. 7A shows a schematic cross-sectional view of the groove 104d of the transposition head 10d from Fig. 6A to Fig. 6D. The substrate 100 has a thickness T. The depth H of the groove 104e is smaller than the thickness T of the substrate 100, and T>H>5 Micrometer (μm), the thickness T is approximately in the range of 1 mm (mm) to 10 mm. In this way, the groove 104d can effectively provide the effect of suppressing the warpage and edge deformation of the substrate 100 on the top surface 100A (see Figures 6A to 6D) of the frame area FA, thereby ensuring the transposition of the transposed area PA Yield rate. In addition, although FIG. 7A shows that the cross-sectional profile of the trench 104d is rectangular, the disclosure is not limited to this. In other embodiments, the profile wheel of the groove 104d The profile can also be tower-shaped (as shown in Figure 7B), arc-shaped (as shown in Figure 7C), inverted triangle (as shown in Figure 7D), and inverted trapezoid (as shown in Figure 7E) Or trapezoid (as shown in Figure 7F). Since the groove 104d of the present disclosure is not limited to the profile profile, it can increase the flexibility and convenience of the manufacturing process.

In summary, in the transposition head proposed in the present disclosure, the groove extends from the top surface into the substrate by providing the groove, and the groove surrounds the transposition area. As a result, the frame area has a reduced top surface area. During demolding, the release point of the interface between the frame area and the mold can be increased, so that the frame area and the mold form a discontinuous stripping line during the stripping process and inhibit the substrate The top surface of the frame area is warped and the edge is deformed, thereby ensuring the transposition yield of the transposition area.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention shall be determined by the scope of the attached patent application.

10‧‧‧Transposed head

100‧‧‧Substrate

100A‧‧‧Top surface

102‧‧‧ bump

104‧‧‧Groove

PA‧‧‧Transpose area

FA‧‧‧Frame Area

Section A-A’‧‧‧

Claims (9)

A transposition head includes: a substrate defining a transposition area and a frame area surrounding the transposition area; and a plurality of bumps arranged on the transposition area, wherein the frame area includes a plurality of grooves, The substrate has a top surface and a bottom surface opposite to each other, the grooves extend from the top surface into the substrate, and the grooves surround the transposed area, and the grooves are point-symmetrical with respect to the transposed area . The transposed head according to claim 1, wherein the grooves have a distance between them, and the ratio of the maximum length of the grooves to the distance is approximately in the range of 1/5000 to 5000. The transposed head according to claim 1, wherein the grooves have a first end and a second end opposite to each other, and the second end is farther from the transposed area than the first end, the The ratio of the number of the grooves to the line length of the second end point is approximately in the range of 0.1 grooves/mm to 100 grooves/mm. The transposed head according to claim 1, wherein the ratio of the number of the grooves to the maximum radius of the grooves is approximately in the range of 0.1/mm to 100/mm. The transposed head according to claim 1, wherein the frame area has a first area in the orthographic projection of the substrate, and the sum of the orthographic projections of the grooves on the substrate has a second area, and the second area is The ratio of the first area is about 1×10 ^-7 to 0.75. The transposed head according to claim 1, wherein a depth of the grooves is H, a thickness of the substrate is T, and T>H>5 micrometers (μm). The transposition head according to claim 1, wherein the grooves extend from the edge of the transposition area to the edge of the substrate. The transposed head according to claim 1, wherein the contour shape of the arrangement of the grooves is substantially the same as the contour shape of the transposed area. The transposed head according to claim 1, wherein a depth of the grooves gradually decreases from the edge of the transposed area toward the edge of the substrate.

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