Transfer head and method of manufacturing the same

Abstract

To provide a transfer head equipped with a transfer pin with improved shape accuracy.SOLUTION: A transfer head according to the present disclosure is a transfer head for use in a mounting device, and includes a base layer having a first main surface, and a plurality of transfer pins protruding from the first main surface and having protruding surfaces for attaching a transfer material.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a transfer head and a method for manufacturing a transfer head. [Background technology]

[0002] For example, Patent Document 1 discloses a transfer head that contains a plurality of stamp pins arranged in a matrix. Each stamp pin is an independent pin.

[0003] In the transfer head of Patent Document 1, flux is attached to the tip of a stamp pin. When the tip of the stamp pin comes into contact with a substrate, the attached flux is transferred to the substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-266980 Summary of the Invention [Problem to be solved by the invention]

[0005] However, due to miniaturization of electronic devices and integration of components on a substrate, there is a demand for higher accuracy in transferring flux and other transfer materials, and therefore a demand for transfer pins with improved shape accuracy.

[0006] An object of the present disclosure is to solve the above-mentioned problems and to provide a transfer head equipped with transfer pins with improved shape accuracy. [Means for solving the problem]

[0007] The transfer head of the present disclosure is a transfer head for use in a mounting device, and comprises a base layer having a first main surface, and a plurality of transfer pins protruding from the first main surface and having protruding surfaces for attaching a transfer material.

[0008] The mounting apparatus according to the present disclosure includes a transfer head.

[0009] A method for manufacturing a transfer head according to the present disclosure is a method for manufacturing a transfer head for use in a mounting device, and includes laminating a resin film on a first main surface of a base layer, partially removing the resin film by photolithography to form a plurality of openings, forming a transfer pin in each of the plurality of openings by plating, and removing the resin film. Effect of the Invention

[0010] According to the present disclosure, it is possible to provide a transfer head equipped with a transfer pin having improved shape accuracy. [Brief description of the drawings]

[0011] [Figure 1] Schematic diagram of a mounting device equipped with a transfer head according to a first embodiment of the present disclosure. [Diagram 2] Schematic diagram of mounting device equipped with transfer head [Diagram 3] Schematic diagram of mounting device equipped with transfer head [Figure 4] Cross-section of the transfer head [Diagram 5] Flow diagram of the transfer head manufacturing method [Figure 6A] 1 is a cross-sectional view showing a method for manufacturing a transfer head; [Figure 6B] 1 is a cross-sectional view showing a method for manufacturing a transfer head; [Figure 6C] 1 is a cross-sectional view showing a method for manufacturing a transfer head; [Figure 6D] 1 is a cross-sectional view showing a method for manufacturing a transfer head; [Figure 6E] 1 is a cross-sectional view showing a method for manufacturing a transfer head; [Figure 7] Cross-sectional view of a transfer head according to Modification 1 [Figure 8] 10A to 10C are cross-sectional views showing a manufacturing method of a transfer head according to a first modified example; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0013] [Embodiment 1] (Overall composition) 1 to 3 are schematic diagrams of a mounting device 50 equipped with a transfer head 1 according to a first embodiment of the present disclosure. As shown in Fig. 1, the mounting device 50 is a device that mounts a component 61, such as a die or an IC chip, on a substrate 62.

[0014] The mounting apparatus 50 has a component supply unit 51, a mounting head 52, a stage 53, a transfer head 1, a moving unit 54, a flux supply unit 55, and a control unit 56.

[0015] The component supply unit 51 supplies a component 61. The mounting head 52 holds the supplied component 61 and mounts it on a substrate 62 supported by a stage 53.

[0016] The transfer head 1 is a member that holds flux on the tips of transfer pins 12 (described later) and transfers the flux onto the surface of a substrate 62. In this specification, the term "flux" includes not only flux itself, but also solder paste containing flux.

[0017] The moving unit 54 moves the transfer head 1 relative to the stage 53 and the flux supply unit 55 .

[0018] The flux supplying unit 55 supplies flux to the transfer head 1. The flux supplying unit 55 may be a container that contains flux.

[0019] The control unit 56 is a component that controls the mounting device 50. The control unit 56 includes a general-purpose processor such as a CPU, MPU, FPGA, DSP, or ASIC that executes a program to realize a predetermined function. The control unit 56 executes a program stored in a memory (not shown) to realize the function.

[0020] 2, before a component 61 is mounted on a board 62, the moving unit 54 lowers the transfer head 1 toward the flux supply unit 55. When the tip of the transfer pin 12 comes into contact with the flux supplied by the flux supply unit 55, the flux adheres to the tip of the transfer pin 12.

[0021] 3, the moving unit 54 moves the transfer head 1 holding the flux above the stage 53, and lowers it toward the substrate 62. When the transfer head 1 comes into contact with the substrate 62, the flux is transferred to the substrate 62.

[0022] (Transfer head configuration) As shown in FIG. 4, the transfer head 1 has a base layer 10, a seed layer 11, and a plurality of transfer pins 12.

[0023] The base layer 10 is a plate-like member having a first main surface R1 and a second main surface R2 on the opposite side. A plurality of transfer pins 12 are provided on the first main surface R1. The second main surface R2 is a surface that is attached to the mounting device 50. The first main surface R1 and the second main surface R2 are flat. "Flat" may mean, for example, that the variation in height of the target plane is 20 μm or less, more preferably 5 μm or less. On the other hand, as long as the surrounding surface is flat, an opening or a recess may be formed in the first main surface R1 or the second main surface R2, and a structure such as a protrusion lower than the transfer pin 12 may be formed on the first main surface R1.

[0024] The base layer 10 may contain, as a main component, Si, glass containing SiO2, Al2O3 (sapphire), or metal. In this case, since the strength of the base layer 10 is high, even when the base layer 10 is cut, the distortion or deformation of the base layer 10 can be suppressed. Therefore, the interval between the transfer pins 12 formed on the base layer 10 and the protruding direction of the transfer pins 12 can be maintained, and the shape precision of the transfer head 1 can be maintained. The base layer 10 is, for example, a silicon wafer. In this case, the base layer 10 can be easily processed by dicing, polishing, or the like.

[0025] The seed layer 11 is a layer provided between the first main surface R1 of the base layer 10 and the transfer pin 12. The seed layer 11 may be one continuous layer covering the entire first main surface R1. The seed layer 11 may be made of metal and may contain, for example, a combination of Ti and Cu, or a metal such as Cu, Ti, or Pd as a main component. When the seed layer 11 contains a combination of Ti and Cu, for example, the seed layer 11 is provided with a Cu layer with a thickness of 300 nm on a Ti layer with a thickness of 100 nm. The seed layer 11 may also have the same main component as the transfer pin 12.

[0026] Other layers may be provided between the base layer 10 and the seed layer 11. For example, when the base layer 10 is a silicon wafer, a silicon oxide film may be provided between the base layer 10 and the seed layer 11.

[0027] The transfer pins 12 are columnar structures protruding from the first main surface R1 of the base layer 10. The transfer head 1 has a plurality of transfer pins 12. The plurality of transfer pins 12 are arranged in a predetermined pattern corresponding to the substrate 62, for example, at equal intervals in the front, back, left and right directions. Although only one row of transfer pins 12 is shown in FIG. 4, in the first embodiment, a plurality of rows are provided in the direction of the paper surface, and the transfer pins 12 are arranged in a matrix. The transfer head 1 has, for example, 100 transfer pins 12 arranged in a 10 by 10 matrix.

[0028] Each transfer pin 12 has a bottom surface P1 in close contact with the seed layer 11, and a protruding surface P2 that protrudes in a direction away from the seed layer 11 and the first main surface R1. The transfer pin 12 has a solid structure between the bottom surface P1 and the protruding surface P2. This configuration improves the strength of the transfer pin 12. The "solid structure" may mean, for example, that the proportion of cavities in the volume of the transfer pin 12 is 10% or less.

[0029] The protruding surface P2 is a surface to which the flux is attached. The protruding surface P2 is flat and, for example, parallel to the first main surface R1. The protruding surface P2 has a surface roughness based on the properties of the flux to be held. When the surface tension of the held flux is small, the surface roughness of the protruding surface P2 may be large, and when the surface tension of the flux is large, the surface roughness of the protruding surface P2 may be small. Also, when the amount of held flux is small, the surface roughness of the protruding surface P2 may be small, and when the amount of held flux is large, the surface roughness of the protruding surface P2 may be large. The surface roughness of the protruding surface P2 may be, for example, on the submicron order.

[0030] The transfer pin 12 has a diameter and height on the order of 100 μm. The multiple transfer pins 12 may have the same or different structures. Specifically, the multiple transfer pins 12 may have the same or different structures in terms of the protruding height from the base layer 10, the shape of the protruding surface P2 as viewed in the thickness direction, the surface roughness of the protruding surface P2, and the like.

[0031] The diameter of the transfer pins 12 is preferably in the range of 50 μm to 100 μm, and the interval between adjacent transfer pins 12, ie, the distance from the end of one transfer pin 12 to the end of an adjacent transfer pin 12, is preferably in the range of 15 μm to 50 μm.

[0032] The transfer pins 12 have a main component different from the main component of the base layer 10. The transfer pins 12 may include a metal as a main component, such as Ni, Cu, or Au. Depending on the composition of the seed layer 11, the main component of the transfer pins 12 may be another material.

[0033] As described above, since the seed layer 11 and the transfer pins 12 are mainly composed of metal, electricity can be passed through the seed layer 11 and the transfer pins 12 by connecting the terminals of an external device to the substrate having a circuit pattern corresponding to the transfer pins 12. Thus, a continuity test of the substrate can be performed by connecting one terminal of the external device to the substrate and the other terminal to the seed layer 11, and bringing the transfer head 1 into contact with the substrate. In addition, by bringing the transfer pins 12 close to the substrate while measuring the voltage of the external device, it can be determined whether the transfer pins 12 are in contact with the substrate.

[0034] (Manufacturing method of transfer head) A method for manufacturing the transfer head 1 will be described with reference to Fig. 5 and Fig. 6A to Fig. 6E. Fig. 5 is a flow diagram of the method for manufacturing the transfer head 1. Fig. 6A to Fig. 6E are cross-sectional views showing the method for manufacturing the transfer head 1.

[0035] 5 and 6A, first, a seed layer 11 is formed on the first main surface R1 of the base layer 10 (S11). For example, the seed layer 11 is formed by sputtering.

[0036] 6B, a resin film 13 is laminated onto the seed layer 11 (S12). For example, the resin film 13 is a photosensitive dry film.

[0037] 6C, the resin film 13 is exposed and developed using a photolithography method (S13). As a result, the resin film 13 in the area corresponding to the transfer pin 12 is removed, and an opening 14 is formed so as to expose the seed layer 11. The opening 14 has a shape and dimensions corresponding to the transfer pin 12.

[0038] 6D, plating is performed to form the transfer pins 12 in the openings 14 (S14). In the first embodiment, the transfer pins 12 are formed by electroplating. By forming a metallic seed layer 11, electrons can move through the seed layer 11, making it easy to perform electroplating. Alternatively, the transfer pins 12 may be formed by electroless plating such as chemical plating.

[0039] Next, as shown in FIG. 6E, the protruding surface P2 of the transfer pin 12 is polished (S15). For example, the polishing is performed using a surface planer. With this configuration, the height and surface roughness of the transfer pin 12 can be adjusted, and the protruding surface P2 can be flattened. Finally, the resin film 13 is removed using a release agent (S16).

[0040] In order to vary the surface roughness of the protruding surface P2 depending on the position on the first main surface R1, for some of the transfer pins 12, blasting with the dry film still attached, etching, increasing the feed rate of the surface planer, or omitting the polishing process may be performed.

[0041] (effect) The transfer head 1 according to the first embodiment can provide the following effects.

[0042] As described above, the transfer head 1 of the first embodiment is a transfer head for use in the mounting apparatus 50. The transfer head 1 includes a base layer 10 having a first main surface R1, and a plurality of transfer pins 12 that protrude from the first main surface R1 and have protruding surfaces P2 to which flux is attached.

[0043] With this configuration, by providing the base layer 10 separately from the transfer pins 12, the base layer 10 can be plated to form the transfer pins 12. By forming the transfer pins 12 by plating, it becomes easy to form the transfer pins 12 with a narrow pitch and a diameter and height on the order of 100 μm with high precision. Therefore, the shape precision of the transfer pins 12 is improved. The transfer pins 12 formed by plating have a solid structure, and the strength of the transfer pins 12 is improved. Therefore, it becomes easy to perform post-processing such as polishing on the transfer pins 12, and the height and surface roughness of the transfer pins 12 can be precisely adjusted, and the shape precision of the transfer pins 12 is further improved. In addition, even when the transfer head 1 is used repeatedly, the deformation of the transfer pins 12 can be suppressed, and the shape precision of the transfer pins 12 can be maintained. By cutting the base layer 10 after plating, multiple transfer heads 1 can be formed from one base layer 10. In addition to improving the manufacturing efficiency of the transfer head 1, since the base layer 10 is provided separately from the transfer pins 12, even if the base layer 10 is cut, distortion and deformation of the transfer pins 12 can be suppressed, and the shape accuracy of the transfer pins 12 can be maintained.

[0044] In the transfer head 1 of the first embodiment, the main component of the base layer 10 and the main component of the transfer pins 12 are different.

[0045] With this configuration, by providing the base layer 10 and the transfer pins 12 from different materials, it becomes easier to make the base layer 10 and the transfer pins 12 into separate members.

[0046] The transfer head 1 of the first embodiment further includes a metallic seed layer 11 between the first main surface R1 of the base layer 10 and the multiple transfer pins 12.

[0047] With this configuration, even if the base layer 10 is made of a material that does not have electrical conductivity, it is possible to perform electroplating on the base layer 10 to form the transfer pins 12. Furthermore, by providing the seed layer 11, the adhesion of the transfer pins 12 to the base layer 10 can be improved.

[0048] In transfer head 1 of the first embodiment, base layer 10 contains Si, SiO2, or Al2O3 as a main component.

[0049] Such a configuration provides high strength, so that even when the base layer 10 is cut, it is possible to suppress distortion or deformation of the base layer 10. In addition, since a processing method for the base layer 10 is established, it is easy to cut the base layer 10 and to flatten the main surfaces R1 and R2 of the base layer 10.

[0050] In the transfer head 1 of the first embodiment, the multiple transfer pins 12 contain metal as a main component.

[0051] Such a configuration allows the transfer pin 12 to be formed by electroplating.

[0052] In the transfer head 1 of the first embodiment, the multiple transfer pins 12 contain Ni, Cu, or Au as a main component.

[0053] Such a configuration makes it easier to form the transfer pins 12 by electroplating.

[0054] In the transfer head 1 of the first embodiment, the multiple transfer pins 12 contain Ni as a main component.

[0055] With such a configuration, the strength of the transfer pin 12 is maintained and the transfer pin 12 can be easily formed by electroplating.

[0056] In the transfer head 1 of the first embodiment, the first main surface R1 of the base layer 10 is flat.

[0057] With this configuration, the heights of the transfer pins 12 can be easily aligned, and the shape precision of the transfer pins 12 can be further improved.

[0058] In the transfer head 1 of the first embodiment, the second main surface R2 opposite to the first main surface R1 is flat.

[0059] With such a configuration, the second main surface R2 of the base layer 10 can be stably attached to a device such as the mounting device 50.

[0060] In the transfer head 1 of the first embodiment, the protruding surface P2 is flat.

[0061] With this configuration, a predetermined amount of flux can be held on the protruding surface P2.

[0062] The mounting apparatus 50 of the first embodiment includes a transfer head 1.

[0063] With this configuration, the mounting apparatus 50 can transfer the flux to a predetermined position by the transfer head 1.

[0064] The manufacturing method of the transfer head 1 of the first embodiment is a manufacturing method of a transfer head 1 for use in a mounting device 50. The manufacturing method includes laminating a resin film 13 on a first main surface R1 of the base layer 10. The manufacturing method includes partially removing the resin film 13 by photolithography to form a plurality of openings 14. The manufacturing method includes forming a transfer pin 12 in each of the plurality of openings 14 by plating. The manufacturing method includes removing the resin film 13.

[0065] With this configuration, the openings 14 are formed by photolithography, and the transfer pins 12 are formed in the openings 14, making it easy to form the transfer pins 12 with a narrow pitch and a diameter and height on the order of 100 μm with high precision. Therefore, the shape precision of the transfer pins 12 is improved.

[0066] The method of manufacturing the transfer head 1 according to the first embodiment further includes polishing the transfer pins 12 after the transfer pins 12 are formed.

[0067] With this configuration, it is possible to adjust the height of the protruding surface P2 of the transfer pin 12 to a desired value. Also, it is possible to adjust the surface roughness of the protruding surface P2 of the transfer pin 12 to a desired value. Therefore, the shape accuracy of the transfer pin 12 is further improved.

[0068] In the first embodiment, the transfer head 1 transfers flux, but the present invention is not limited to this. The transfer head 1 may transfer other objects. Examples of the other objects include cleaning agents, molten metals, metal pastes, glass frits, pure water, or other chemicals, pastes, powders, or solids used in the modification process, bonding process, and semiconductor manufacturing process. When the transfer head 1 transfers other objects, the material of the transfer pins 12 and the surface roughness of the protruding surface P2 may be adjusted based on the type of the object.

[0069] In the first embodiment, an example in which the transfer head 1 has the seed layer 11 has been described, but the present invention is not limited to this. For example, when the base layer 10 contains a metal as a main component, it is possible to omit the seed layer 11, and the transfer pins 12 are formed directly on the first main surface R1. Therefore, even when the seed layer 11 is omitted, the transfer head 1 has an interface between the first main surface R1 of the base layer 10 and the transfer pins 12.

[0070] In the first embodiment, an example in which the main component of the base layer 10 and the main component of the transfer pin 12 are different has been described, but the present invention is not limited to this. The main component of the base layer 10 and the main component of the transfer pin 12 may be the same. For example, the main component of the base layer 10 and the main component of the transfer pin 12 may be Cu or Ni.

[0071] In the first embodiment, the transfer pin 12 has one layer, but the present invention is not limited to this. As shown in the first modified example, the transfer pin 12 may have a multi-layer structure.

[0072] In the first embodiment, the transfer pins 12 are flattened before the resin film 13 is removed, but the present invention is not limited to this. For example, the transfer pins 12 may be flattened after the resin film 13 is removed.

[0073] (Variation 1) Fig. 7 is a cross-sectional view showing the transfer head 21 according to Modification 1. As shown in Fig. 7, the transfer head 21 according to Modification 1 differs from the transfer head 1 according to the embodiment 1 in that the transfer pins 32 have a multi-layer structure.

[0074] Unless otherwise specified, the transfer head 21 according to the modified example 1 has a common structure with the transfer head 1 according to the embodiment 1. The following describes the points that differ from the embodiment 1.

[0075] The transfer pin 32 has a first layer 32A that adheres to the seed layer 11, and a second layer 32B provided on the first layer 32A. The second layer 32B has a protruding surface P2 to which flux is attached. The first layer 32A and the second layer 32B have different main components. For example, the first layer 32A contains Ni as a main component, and the second layer 32B contains Cu as a main component. Since flux easily adheres to Cu, the first layer 32A can maintain the strength of the transfer pin 32 while improving the flux retention function of the protruding surface P2 of the second layer 32B.

[0076] The thickness of the first layer 32A is greater than the thickness of the second layer 32B. With this configuration, if the first layer 32A is made of a material stronger than the second layer 32B, the strength of the transfer pin 32 can be improved.

[0077] Fig. 8 is a cross-sectional view showing a manufacturing method of the transfer head 21 according to the modified example 1. As shown in Fig. 8, after the first layer 32A is formed by plating, the second layer 32B is formed by another method such as sputtering. The second layer 32B may be formed by plating.

[0078] The transfer head in a first aspect is a transfer head for use in a mounting device, and comprises a base layer having a first main surface, and a plurality of transfer pins protruding from the first main surface and having protruding surfaces for attaching a transfer material.

[0079] In the transfer head of the second embodiment, the main component of the base layer is different from the main component of the transfer pin in the transfer head of the first embodiment.

[0080] A transfer head according to a third aspect is the transfer head according to the first or second aspect, further comprising a metallic seed layer between the first main surface of the base layer and the plurality of transfer pins.

[0081] As the transfer head in a fourth aspect, in the transfer head in the third aspect, the base layer contains Si, SiO2 or Al2O3 as a main component.

[0082] As a transfer head in a fifth aspect, in the transfer head in any one of the first to fourth aspects, the multiple transfer pins contain metal as a main component.

[0083] In a sixth aspect of the transfer head, in any one of the first to fifth aspects, the transfer pins contain Ni, Cu, or Au as a main component.

[0084] As a transfer head in a seventh aspect, in the transfer head in any one of the first to sixth aspects, the multiple transfer pins contain Ni as a main component.

[0085] As a transfer head in an eighth aspect, in any one of the transfer heads in the first to seventh aspects, the first main surface of the base layer is flat.

[0086] As the transfer head in a ninth aspect, in the transfer head in any one of the first to eighth aspects, a second main surface opposite to the first main surface is flat.

[0087] As a transfer head in a tenth aspect, in any one of the transfer heads in the first to ninth aspects, the protruding surface is flat.

[0088] A mounting apparatus in an eleventh aspect includes a transfer head in any one of the first to tenth aspects.

[0089] A manufacturing method for a transfer head in a 12th aspect is a manufacturing method for a transfer head for use in a mounting device, and includes laminating a resin film on a first main surface of a base layer, partially removing the resin film by photolithography to form a plurality of openings, forming a transfer pin in each of the plurality of openings by plating, and removing the resin film.

[0090] A thirteenth aspect of the method for producing a transfer head is the twelfth aspect of the method for producing a transfer head, further comprising polishing the transfer pins after forming the transfer pins.

[0091] As a method for manufacturing a transfer head in a fourteenth aspect, in the method for manufacturing a transfer head in the twelfth or thirteenth aspect, the transfer pin contains Ni as a main component.

[0092] A fifteenth aspect of the method for producing a transfer head is the method for producing a transfer head in any one of the twelfth to fourteenth aspects, in which a main component of the base layer and a main component of the transfer pin are different.

[0093] Although the present disclosure has been fully described in connection with the preferred embodiments with reference to the accompanying drawings, various changes and modifications will be apparent to those skilled in the art, and such changes and modifications should be understood to be included within the scope of the present invention as defined by the appended claims, unless they depart therefrom. [Industrial Applicability]

[0094] The transfer head of the present disclosure has the effect of transferring flux to a predetermined position on a substrate, and is particularly useful in mounting devices that mount components. [Explanation of symbols]

[0095] 1 Transfer head 10 Base Layer 11 Seed layer 12 Transfer pin 13 Resin film 14 Openings 50 Mounting Equipment R1 First main surface R2 Second main surface P1 Bottom P2 protruding surface

Claims

1. 1. A transfer head for use in a mounting apparatus, comprising: a base layer having a first major surface; a plurality of transfer pins protruding from the first main surface and having protruding surfaces for attaching a transfer material.

2. The transfer head of claim 1 , wherein a main component of the base layer is different from a main component of the transfer pin.

3. The transfer head of claim 1 , further comprising a metallic seed layer between the first major surface of the base layer and the plurality of transfer pins.

4. The base layer is mainly composed of Si and SiO ２ Or Al ２ O ３ The transfer head of claim 3 comprising:

5. The transfer head of claim 1 , wherein the plurality of transfer pins include a metal as a primary component.

6. The transfer head of claim 1 , wherein the plurality of transfer pins contain Ni, Cu, or Au as a main component.

7. The transfer head of claim 1 , wherein the plurality of transfer pins contain Ni as a main component.

8. The transfer head of claim 1 , wherein the first major surface of the base layer is flat.

9. The transfer head of claim 1 , wherein a second major surface opposite the first major surface is flat.

10. The transfer head of claim 1 , wherein the protruding surface is flat.

11. A mounting device comprising the transfer head according to any one of claims 1 to 10.

12. 1. A method of manufacturing a transfer head for use in a mounting device, comprising: laminating a resin film onto a first main surface of a base layer; partially removing the resin film by photolithography to form a plurality of openings; forming a transfer pin in each of the plurality of openings by plating; removing the resin film; A method for manufacturing a transfer head, comprising:

13. The method of claim 12 , further comprising polishing the transfer pins after forming the transfer pins.

14. The method for manufacturing a transfer head according to claim 12 , wherein the transfer pin contains Ni as a main component.

15. The method for manufacturing a transfer head according to claim 12 , wherein a main component of the base layer is different from a main component of the transfer pin.

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