Transfer stamp and method for forming a transfer stamp - Patent application

Abstract

The invention relates to a transfer stamp for transferring optoelectronic components, which comprises a stamp body (10) having a height and a stamp surface (11) with a side length, the ratio of height to side length being greater than 1.3, in particular greater than 2. A stabilization layer (101) made of a material different from that of the stamp body (10), is applied to the side of the stamp body, the stamp surface (11) remaining material-free, the stabilization layer material having a higher rigidity than the stamp body material.

Description

[Technical Field]

[0001] This application claims priority from German Patent Application No. 102022122478.3, filed Sep. 05, 2022, the disclosure of which is hereby incorporated by reference.

[0002] The present invention relates to a transfer stamp for transferring semiconductor components and a method for forming such a transfer stamp. [Background technology]

[0003] When transferring multiple small (<20 μm) semiconductor components in parallel by a stamping process (e.g., using a structured silicone mat), the mechanical properties of the stamp elastomer create various problems when picking up and placing the devices. For one thing, the stamp itself is made with a certain degree of adhesion, and in this case, the strength of this adhesion must be carefully selected.

[0004] Current transfer stamps are made of materials with defined hardness and tackiness, often PDMS or silicone. Currently, different material mixtures allow for pre-adjusted tackiness and hardness. However, the tackiness and hardness of PDMS cannot be independently adjusted.

[0005] During placement of the semiconductor component, the semiconductor component is often removed using a certain degree of shear force, i.e., not only by a force acting perpendicular to the surface. The same applies at least partially to the receiving process, although in this specification, this may also be done without the use of shear force. This requires a defined tolerance in the dimensions and a defined shape for the stamp cushion to ensure that the semiconductor components can be placed as closely as possible. In this case, the hardness or rigidity of the elastomer-based stamp is generally a problem. While a higher rigidity certainly allows for a higher tolerance, especially when transferring semiconductor components with side lengths of less than 10 μm or less than 5 μm, in practice, the shear movement during component placement imposes a limiting range on the stamp dimensions.

[0006] It has therefore been found that with the stamp materials used so far (mainly elastomer-based methods), the stamp has a height to edge length ratio of about 1, but especially not greater than this, because otherwise the deflection would be too strong. Furthermore, only small placing forces can be achieved in this way.

[0007] When transferring multiple parts simultaneously, mechanical stability is required, which results in a certain minimum spacing between two adjacent stamps.

[0008] Therefore, there is a need to provide a transfer stamp that overcomes at least some of the above-mentioned problems, thereby allowing a larger quantity of devices to be transferred simultaneously. Summary of the Invention

[0009] This need is taken into account by the subject matter of the independent claims. Improved versions and configurations of the proposed principle are set out in the dependent claims.

[0010] The inventors propose that an additional layer applied to the side of the actual stamp mechanically stabilizes the stamp, particularly against further shear forces. Meanwhile, the contact surface required for transfer remains unchanged. This advantageously achieves various effects. For one, it allows the use of different interconnection materials, particularly those requiring increased placement forces. The additional stabilization also makes it possible to change the ratio of the height to the side length in favor of the stamp height. In short, the stabilization allows for longer stamps. Correspondingly, the density of transfer stamps according to the proposed principle can be increased, allowing more components to be transferred simultaneously.

[0011] The proposed principle allows the transfer of devices with dimensions of 1 μm to 5 μm without the need for laborious optimization of machine precision, and allows the use of other substrates or panels that could not be used before due to tight height tolerances.

[0012] In some embodiments, a transfer stamp for transferring optoelectronic components comprises one or more stamp bodies having a stamping surface with a height and a side length, the ratio of height to side length being greater than 1.2, particularly greater than 2. Thus, the stamp is significantly longer than its corresponding side length, and thus the ratio may be, particularly, between 1.5 and 5. In some embodiments, the ratio is greater than 2 and between 2.5 and 4.5.

[0013] According to the proposed principle, a stability layer made of a material different from the stamp body is applied to the side of the stamp body, leaving the stamp surface substantially free of material. The material of the stability layer has a higher rigidity than the material of the stamp body. In this context, a material different from the stamp body also means a material that is fundamentally different from the material of the stamp body, but which arises from the material of the stamp body by chemical or physical action (for example, temperature, pressure or plasma treatment).

[0014] Thus, the proposed principle provides a transfer stamp in which shear motion reduces the adhesion between the stamp and the device to be transferred, thereby enabling reliable placement of the device on the receiver surface. In addition to higher transfer yields, shorter process times are achieved. Furthermore, additional linear freedom or a larger process parameter space is possible for each different receiver surface. Furthermore, surprisingly, it has been found that lateral adhesion is dramatically reduced due to the stability layer. This significantly reduces tilting of the part to be transferred in the event of slight misalignment, thereby improving placement tolerances and yields. In some embodiments, a transfer stamp according to the proposed principle includes a support longitudinally connected to the stamp body. This support may transition to a wider base in some embodiments, particularly useful for improving stability. The support has a surface on which the stamp body is arranged, particularly concentrically. In this case, this surface may be larger than the stamp surface.

[0015] In the following description, reference is often made to only one stamp body and one support, but this should be understood to apply equivalently to multiple stamp bodies and multiple supports.

[0016] In some embodiments, the support has a different material than the stamp body. In this regard, the support may be made of a material that is more rigid than the material of the stamp body. The support may be made transparent, so that the transfer process or the result of the transfer process can be checked from the support.

[0017] In some embodiments, the support is at least partially, especially on the sides, covered with the material of the stability layer, which in part allows for possibly easier manufacturing or allows for additional functionality to be incorporated therein.

[0018] In this case, the material of the stamp body may be a plastic that is softer than the stabilizing material. Possible materials are, for example, based on PDMS. Various components may be used as the material of the stabilizing layer. Coatings made of SiO2 or graphite have proven particularly suitable. In other embodiments, a metal may be applied to the side surface as a thin layer, for example, by electroplating or vapor deposition. Metals are conductive, which may enable additional functions. Ag, Au, Ni, Ti, or Pt are particularly suitable as metals. Composites, such as TiN, are also possible. In further embodiments, the material of the side surface of the stamp may be (pre)treated with plasma, which chemically or physically changes the surface. In some embodiments, the surface of the side surface may also be glass-coated or oxidized.

[0019] One aspect relates to the thickness of the stabilizing layer. It is desirable for the layer to be thick enough to provide the necessary mechanical rigidity against shear forces. It has been found that, for shorter edge lengths, the thickness should be proportionally increased to ensure the necessary rigidity. Therefore, in some embodiments, it is proposed that the thickness of the stabilizing layer be within the range of 1 / 1000 to 1 / 50, particularly 1 / 800 to 1 / 100, and particularly 1 / 700 to 1 / 200 of the edge length of the stamping surface. In other words, the thickness of the stabilizing layer depends on the edge length of the stamping surface. In some embodiments, for edge lengths of less than 10 μm, the layer thickness is within the range of several tens of nanometers, i.e., between 20 nm and 90 nm. Therefore, in some embodiments, the thickness is between 5 nm and 100 nm, particularly between 10 nm and 75 nm, and particularly between 20 nm and 50 nm.

[0020] Additionally, the material of the stabilization layer can affect the required thickness. For example, SiO2 generally has a smaller thickness than a layer made of metal. In some embodiments, a stamp surface has a side length in the range of 2 μm to 50 μm. In particular, this side length can be 2 μm to 30 μm, especially less than 10 μm. For example, for a side length of 10 μm, the stamp length is in the range of 13 μm to 50 μm, especially between 12 μm and 25 μm.

[0021] One aspect concerns the area near the stamping surface, which itself remains essentially free of the material of the stability layer and thus has a defined adhesion, which reduces tilting during placement due to displacement tolerances, since the parts adhere specifically to the stamping surface but no longer along the sides as with conventional transfer stamps.

[0022] However, a further aspect is the dissipated placement force, which in some embodiments results in a slight compression of the stamp perpendicular to the stamp surface. In this case, to ensure contact of the stamp surface with the part to be transferred even during slight compression or thermal length changes, in some embodiments, a small end region along the side edge of the stamp surface may be specified to remain free of stability layer material. In other words, the stability layer is slightly depressed relative to the stamp surface. This free region may be within a range of 1 nm to 30 nm, particularly 2 nm to 10 nm, on the side starting from the stamp surface.

[0023] Some aspects relate to the shape of the stamp body. The stamp body may have a rectangular parallelepiped shape, with the longest side of the rectangular parallelepiped defining the height. Alternatively, the sides of the stamp body may be tapered toward the stamping surface. Thus, in some aspects, the stamp body defines a truncated pyramid. In other aspects, the stamp body defines a truncated cone.

[0024] A further aspect relates to a method for forming a transfer stamp or multiple such transfer stamps. In the proposed method, a support is provided with a stamp body. The stamp body has a height and a stamp face having a side length, where the ratio of the height to the side length is greater than 1.3, particularly greater than 2. The method also includes forming a stability layer on at least the side of the stamp body, where the stamp face remains without the stability layer and the material of the stability layer has a higher rigidity than the material of the stamp body.

[0025] Depending on the configuration and, if necessary, the design requirements, the stamp surface may be covered with, for example, a plate, a dummy semiconductor body, or the like, to form a stability layer. In this case, the cover is preferably at least as large as the stamp surface in order to completely cover the stamp surface. In some embodiments, the cover may be larger and therefore extend beyond the stamp surface. A metal, particularly Ag, Au, PT, Ni, or Ti, may then be applied to at least the side surface of the stamp body. Graphite may also be applied to the side surface of the stamp body. This may be done, for example, by electroplating, vapor deposition, sputtering, or deposition.

[0026] In some embodiments, the side surface may be treated with plasma. This can cause a physical or chemical reaction, depending on the stamp body material, which results in a more rigid and stable layer. In some embodiments, the surface may be hardened, thereby forming a stable layer. Glass coating, i.e., the application or formation of glass on the surface, is also possible. In some embodiments, the glass is SiO2.

[0027] Depending on the configuration, the cover applied to the stamping surface creates a shadow area. This prevents the stabilization layer from reaching the edge of the stamping surface, leaving the area of ​​the side of the stamp body adjacent to the stamping surface free of stabilization layer material. The area free of material at the upper edge can have a height of 1 nm to 30 nm, in particular 2 nm to 10 nm, from the upper edge toward the support.

[0028] In some aspects, the step of providing a support with a stamp body includes providing a support with a mounting surface, providing a stamp body with a stamping surface, and attaching the stamp body to the support. The support and stamp body may be made of the same material, but may also be made of different materials. In particular, the support may have a more rigid material than the stamp body. Alternatively, the support and stamp body may be made integrally.

[0029] An adhesive may be used to fasten the stamp body to the support. However, it is also possible to activate the surfaces to be bonded together, for example by plasma treatment. The stamp body may then be placed on the activated support surface. In some embodiments, the surfaces are bonded together by bringing the support surface into contact with a planar material reservoir, and then moving the support and the material reservoir away from each other again.

[0030] This causes the material forming the stamp body to be pulled or removed from the material reservoir. To simplify this process, a target break point may be provided. In this case, it is advantageous if the stamp material is softer or more elastic than the material of the support. In some embodiments, an additional release layer may be provided between the material reservoir and the temporary carrier, allowing the stamp material to be released from the reservoir in the desired shape. Furthermore, the temporary carrier may be structured and then prepared with the material reservoir. In this way, the material for the stamp body can be provided in a recess in the temporary carrier that is provided for this material. A release layer may be provided for easier release.

[0031] In some aspects, the stamp body is provided on a temporary carrier that has an adhesion force to the stamp body that is less than the adhesion force between the surface of the support and the surface of the stamp body, allowing the support and stamp body to be manufactured separately and then bonded together.

[0032] Further aspects and embodiments according to the proposed principles will be disclosed with respect to different embodiments and examples, which will be explained in detail in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0033] [Figure 1] 1 is a perspective view of a transfer stamp having some aspects according to the proposed principles; [Figure 2A] 1A-1C illustrate method steps for forming a transfer stamp according to some embodiments of the proposed principles. [Figure 2B] 1A-1C illustrate method steps for forming a transfer stamp according to some aspects of the proposed principles. [Figure 2C] 1A-1C illustrate method steps for forming a transfer stamp according to some aspects of the proposed principles. [Figure 3A] 10A-10C illustrate another embodiment of a method for forming a transfer stamp according to some aspects of the proposed principles. [Figure 3B] 10A-10C illustrate another embodiment of a method for forming a transfer stamp according to some aspects of the proposed principles. [Figure 3C] 10A-10C illustrate another embodiment of a method for forming a transfer stamp according to some aspects of the proposed principles. [Figure 3D] 10A-10C illustrate another embodiment of a method for forming a transfer stamp according to some aspects of the proposed principles. [Figure 4A] 10A-10C illustrate another embodiment of a method for forming a transfer stamp according to some aspects of the proposed principles. [Figure 4B] 10A-10C illustrate another embodiment of a method for forming a transfer stamp according to some aspects of the proposed principles. [Figure 4C] 10A-10C illustrate another embodiment of a method for forming a transfer stamp according to some aspects of the proposed principles. [Figure 5A]10A-10C illustrate steps of yet another embodiment of a method for forming a transfer stamp according to some aspects of the proposed principles. [Figure 5B] 10A-10C illustrate steps of yet another embodiment of a method for forming a transfer stamp according to some aspects of the proposed principles. DETAILED DESCRIPTION OF THE INVENTION

[0034] The following embodiments and examples illustrate various aspects and their combinations according to the proposed principles. The embodiments and examples are not always drawn to scale. Also, various elements may be drawn enlarged or reduced in size to highlight individual aspects. It is clear that the individual aspects and features of the embodiments and examples shown in the drawings may be readily combined with one another without compromising the principles according to the invention. Some aspects have regular structures or shapes. It should be noted that slight deviations from the ideal shapes may occur in practice, but do not deviate from the spirit of the invention.

[0035] Additionally, individual figures, features, and aspects are not necessarily drawn to scale, nor are the proportions between individual elements necessarily correct. Some aspects and features may be more clearly seen by illustrating them at an enlarged scale. However, terms such as "top," "upper," "lower," "belower," "larger," "smaller," and the like, are properly indicated in relation to elements in the figures. Thus, such relationships between elements can be derived based on the figures.

[0036] 1 shows an embodiment of a transfer stamp according to the proposed principle. This transfer stamp is attached to an elastomer carrier 13 and, in addition to the base 13, essentially comprises a support 12 and a stamp body 10 arranged on this support. In this illustrated embodiment, the support 12 is square and has a height H and a face length L. The length L and the height H are selected so that the supports 12 are supported at a sufficient distance from adjacent supports 12 so that they do not act on the semiconductor components to be transferred during component transfer, in particular during the shear movements required for this purpose.

[0037] The stamp body 10 is located in the center of the surface 120 of the support 12. This stamp body 10 also has a square base surface that forms the stamp surface 11 on its upper surface. The stamp body 10 is made of PDMS, although other plastics are also suitable. The elastomeric material PDMS may optionally contain additives that modify its elasticity or stiffness. Since the side length l of the stamp surface 11 is shorter than the height h of the stamp body 10, the ratio of h to the side length l is greater than 1 (h / l>1), e.g., in the range of 1.5 to 2.5 as shown in FIG. 1 . The actual stamp surface is located on the upper surface of the stamp body 10. This stamp surface interacts with the semiconductor component to be transferred and, for this purpose, has a slightly adhesive surface relative to the material of the semiconductor component.

[0038] According to the proposed principle, the lateral surfaces of the stamp body 10 are covered with a stabilizing layer 101. This stabilizing layer 101 is applied to the lateral surfaces of the stamp body 10 and has a stiffness higher than the stiffness of the elastomeric material of the stamp body 10. In this case, the stabilizing layer 101 is applied to the lateral surfaces of the stamp body 10, in particular in the form of a thin coating.

[0039] In other words, the stabilizing material applied to the sides of the stamp body 10 is less elastic and prevents or reduces deflection of the stamp body 10 during shear movements during the semiconductor body placement or pick-up process.

[0040] In this way, the height h of the stamp body 10 can be increased without shear forces occurring during pick-up or placement of the semiconductor body causing damage to the stamp body or causing adjacent transfer stamps to interfere with each other. The greater height h also ensures a greater distance of the semiconductor component to the support 12 during the pick-up process, so that misalignment of the stamp body during the transfer process has less of an effect. In particular, the greater height h of the stamp body 10 ensures that the support 12 does not accidentally interact with the semiconductor component.

[0041] The material 101 on the sides of the support may also extend onto the surface 120 of the support 12 and onto the surfaces of the sides and base 13. In an embodiment, the material may be evaporated, sputtered or otherwise applied to the surface of the transfer stamp shown in Figure 1 during manufacture of the stamp, with the thickness of the applied material 101 being selected to achieve sufficient rigidity depending on the material of the stamp body 10.

[0042] The thickness required for this purpose therefore depends not only on the material of the stamp body 10 and its mechanical or elastic properties, but also on the properties of the applied material itself. An example of such a material is silicon dioxide SiO2 applied to the side in the form of a glass coating as material 101. In this case, the thickness of the silicon dioxide SiO2 is in the range of a few nanometers to several tens of nanometers. Alternative materials for applying increased rigidity to the material of the stamp body 10 can be graphite or various metals. The latter also have the advantage that they are electrically conductive, thereby preventing unwanted electrostatic charging during transport. Possible metals include, for example, silver, gold, platinum, but also titanium or nickel.

[0043] 2A to 2C show different method steps for manufacturing a transfer stamp 1 according to the proposed principle.

[0044] 2A, the transfer stamp material is applied to a transparent, sturdy base 130 and is already correspondingly structured. Each transfer stamp 1 comprises a support 12 and a stamp body 10 arranged on the support. The support 12, stamp body 10, and base material 13 are manufactured in one piece and comprise an elastic plastic, such as PDMS Sylgard 184®. This material has only slight adhesion to the semiconductor material to be transferred, so that the semiconductor component adheres well to the stamp cushion when it comes into contact with the stamp surface 11 and can be picked up from the carrier by the stamp cushion.

[0045] 2A, the height h of the stamp body 10 is clearly greater than the corresponding side length l of the stamping surface 11. The ratio of the height h to the side length is in the range of 2-3 in this embodiment.

[0046] To protect the stamp surface 11 from subsequent process steps, a cover 25, e.g., a plate made of semiconductor material, is applied to the stamp surface 11, completely covering the exposed stamp surface 11. Then, as shown in FIG. 2B , the side surfaces of the stamp body 10, as well as the side surfaces of the support 12 and the surface of the base 13, are covered with a stabilizing material 101. In this case, the stabilizing layer 101 is applied to the side surfaces of the stamp bodies 10, particularly in the form of a thin coating, so that the areas between the stamp bodies 10 or the support bodies remain free of the stabilizing material 101. Accordingly, the stabilizing material 101 does not fill the intermediate spaces between the stamp bodies, but only covers the side surfaces of the stamp bodies 10.

[0047] As already mentioned, this material has a higher rigidity than the plastic used for the stamp body 10. In this case, the thickness of the applied material is in the range of approximately 20 nm to 100 nm and depends, inter alia, on the side length l of the stamp face. In general, the greater the ratio h / l, the greater the thickness of the material of the stabilization layer. The protection applied to the stamp face 11 prevents the deposition of the stabilization material 101 on the stamp face. The cover provided on the stamp face 11 is then removed again in FIG. 2C, thereby exposing the stamp face.

[0048] During the deposition of material 101 on the flank, in some embodiments, the protective body 25 applied to the stamping surface 11 may protrude slightly beyond the edge of the stamping surface. This is advantageous, in part, to reduce the effects of possible misalignment, i.e., slightly offset application of the cover 25 to the surface 11, or slippage during the process. Secondly, the protruding area of ​​the cover 25 forms a shadow along the edge region of the flank, i.e., the area adjacent to the stamping surface. This leaves the edge or marginal area of ​​the flank near the stamping surface 11 without stabilizing material, since little or no stabilizing material is applied to this area.

[0049] Simply put, the height h of the stamp body protrudes only slightly beyond the height of the flanks of the stabilization by a small amount, ranging from a few nanometers to a few tens of nanometers. Alternatively, the stabilization material is slightly depressed by this amount. This has the advantage that the flanks of the stabilization do not come into contact with the semiconductor component due to slight compression of the stamp surface when pressed against the semiconductor component. This improves adhesion of the stamp surface 11 to the semiconductor component, without the flanks of the stabilization coming into contact with the semiconductor component and possibly damaging it. The completed transfer stamp of the embodiment shown in FIG. 2C may be used for multiple transfers of elements.

[0050] 3A-3D show another embodiment for producing a transfer stamp according to the proposed principle. In this configuration, a stamp substrate is provided, which comprises a base 13 and a support 12' attached to the base. The support 12' and the base 13 comprise a material that is significantly harder and more rigid than the material of the subsequent stamp body 10. In the next step, shown in FIG. 3B, the surface 120 of the support 12' is subjected to a plasma process, which activates the surface. This activation creates free bonds that allow particularly good adhesion of the significantly softer second layer 100, which is fixed as a material reservoir to the temporary carrier 20.

[0051] As shown in the embodiment of FIG. 3B, the plasma-activated surface 120' is positioned facing the surface of the material 100 and pressed stationary against this surface. Additionally, the surface of the softer material reservoir for the stamp body 10 may be activated by a corresponding plasma process. After pressing the surface 120' against the surface of the reservoir 100, the surfaces adhere to each other, and the plasma-activated surfaces are bonded together. The support 12' is then removed again, which causes a portion of the material of the stamp body 10 to peel off, leaving the truncated pyramidal structure 10' on the surface of the support 12' as the stamp body. The truncated pyramidal structure 10' is relatively firmly bonded to the support 12' and may be provided for subsequent part transfer by subsequent processes.

[0052] Depending on the process design, in this example, a frustoconical structure may be formed.

[0053] In a subsequent step, the stamping surface of the structure 10' is again covered with a protective cover, and then a stabilizing material 101 is applied to the sides of the stamp body 10' and the sides of the support 12'. The resulting structure is then shown in FIG. 3D. In this case, the stabilizing layer 101 is applied, in particular in the form of a thin coating, to the sides of the structure 10' and the sides of the support 12', so that the areas between the structures 10' or the supports remain free of the stabilizing material 101. This stabilizing material 101 accordingly does not fill the intermediate spaces between the stamp bodies and the supports 12', but only covers the sides of the stamp body 10' and the sides of the support 12'.

[0054] In this embodiment, the diameter of the stamp body 10' tapers towards the stamping face 11, so that the stamp body 10' forms a truncated pyramid or truncated cone. The resulting stamp differs from the previous embodiment in that the side lengths remain substantially equal over the height while the stamp body consists of a rectangular parallelepiped structure.

[0055] The embodiment shown in Figures 3A-3C, which includes different materials for the support 12 and the stamp body 10, may further be modified to achieve different configurations adapted to the parts to be transferred.

[0056] 4A-4C further illustrate some method steps for producing a number of transfer stamps according to the proposed principle. In Fig. 4A, again a substrate 13' with a support 12' is provided, which in Fig. 4B is activated on its surface via a plasma process. Also provided is a temporary carrier 20 with a number of rectangular parallelepiped stamp bodies 10, the surfaces of which are also activated by a plasma process.

[0057] In this case, the spacing between the individual stamp bodies 10 corresponds to the spacing between the centers of the respective supports 12'. The carrier 20 with the respective elements and the base body 13' are placed opposite each other, and the surfaces of the stamp bodies 10 are bonded to the support 12. Thus, after removing the glass carrier 20, the stamp bodies 10 are left on the support 12 and can be supplied with a stable material for subsequent process steps. In this way, for example, the embodiment shown in FIG. 1 can be realized.

[0058] 5A and 5B show further configurations of the transfer stamp. In FIG. 5A, a substrate is provided which, in addition to the base 13′ and the support 12′, also has a concentrically arranged stamp body 10″. The material of the stamp body 10″ is the same as that of the support 12′, and the side length of the stamp body 10″ at the upper or lower surface is clearly shorter than the corresponding height to the support 12′. This also provides a height to side length ratio greater than 1, which in the present invention is in the range of 2-3.

[0059] This assembly is placed against a structured glass carrier 20, which has a number of evenly spaced recesses into which the release layer 30 and the soft elastomeric material 103 present in the release layer 30 are introduced. The plasma activated surface of the stamp body 10'' is introduced into the recesses, which bonds the material 103 to the surface, so that after detachment the material can also be easily removed from the recesses by the release layer 30.

[0060] The release occurs due to tearing of the elastomeric material 103 at the edges of the recesses. In an alternative implementation, the glass carrier 20 is configured so that the release layer 30 is present only at the bottom of the recesses as well as at the side edges of the recesses. In this case, the introduced soft elastomeric layer is brought into contact with the plasma-activated surface of the stamp body 10" at the surface and is thus bonded. During the separation movement, the elastomeric layer in the recesses is easily released and cleaves at the side edges. Additional structuring of the release layer to fit the recesses therefore provides a further improvement and results in a defined stamp made of soft elastomeric material.

[0061] A small elastomeric stamp cushion 103 made of the softer PDMS material is thus formed on top of the stamp body 10''. After removal of the stamp cushion 103, the sides of the stamp cushion 103, the sides of the remaining body 10'' and the sides of the support 12' are then coated with a stable material. The transfer stamp thus formed is shown in Figure 5B. [Explanation of symbols]

[0062] 1 Transfer Stamp 10 Stamp body 10' Stamp Body 10'' stamp body 11 Stamp surface 12 Support 12' support 13 Base 20 Temporary Carriers 25 Cover 101 Layer of Stability 103 Stamp Cushion 120 surface 120' activated surface 130 base H,h height L,l length

Claims

1. 1. A transfer stamp for transferring a number of optoelectronic components, comprising: a number of stamp bodies (10, 10', 10'') each having a height (h) and a stamping surface (11) with a side length (l), the ratio of said height to said side length being greater than 1.3, in particular greater than 2; a stability layer (101) made of a material different from that of the stamp body (10, 10', 10'') provided on the side of the stamp body (10, 10', 10''), the stamp surface (11) remaining substantially free of said material, the stability layer (101) material having a higher stiffness than the material of the stamp body (10, 10', 10''); a number of supports (12, 12') each connected longitudinally to one of the stamp bodies (10, 10', 10''), the supports (12, 12') having a surface (120) which is in particular concentrically arranged and which is larger than the stamping surface (11); A transfer stamp comprising:

2. 2. The transfer stamp according to claim 1, wherein the support (12, 12') comprises a material different from that of the stamp body (10, 10', 10''), in particular a material having a higher stiffness than the material of the stamp body.

3. Transfer stamp according to claim 1 or 2, wherein the support (12, 12') is at least partially, in particular at the side surfaces, covered by the material of the stability layer (101).

4. The material of the stability layer (101) is selected from the group: Yes ２ 、 graphite, Metals, in particular Ag, Au, Ti, and TiN The transfer stamp according to any one of claims 1 to 3, comprising at least one material from:

5. 5. Transfer stamp according to any one of claims 1 to 4, wherein the thickness of the stability layer (101) is 1 / 1000 to 1 / 50, in particular 1 / 800 to 1 / 100, in particular 1 / 700 to 1 / 200 of the length (l) of one side of the stamping surface (11) and / or is between 5 nm and 100 nm, in particular 10 nm to 75 nm, in particular 20 nm to 50 nm.

6. 6. Transfer stamp according to any one of claims 1 to 5, wherein one stamping surface (11) has a side length (l) in the range of 2 μm to 50 μm, in particular in the range of 2 μm to 30 μm, in particular less than 10 μm.

7. 7. The transfer stamp according to claim 1, wherein a region of the side surface of the stamp body (10, 10', 10'') adjacent to the stamp surface, in particular a region in the range of 1 nm to 30 nm, in particular in the range of 2 nm to 10 nm on the side surface starting from the stamp surface, is free of the material of the stability layer.

8. Transfer stamp according to any one of the preceding claims, wherein the sides of the stamp body (10) are tapered towards the stamping surface.

9. 1. A method for forming a transfer stamp, comprising: - providing a number of supports (12) each with one stamp body having a height and a stamping surface with a side length, the ratio of said height to said side length being greater than 1.3, in particular greater than 2; - forming a stability layer (101) at least on the side of the stamp body (10, 10', 10''), the stamping face (11) remaining without said stability layer, the material of which is more rigid than the material of the stamp body (10, 10', 10''); A method comprising:

10. The step of forming the stability layer (101) comprises: - covering said stamping surface (11) with a cover (25), in particular a plate, and depositing a metal, in particular Ag, Au or Ti, on at least the side surface of the stamp body; depositing graphite on the side surface of the stamp body; - treating at least the side surface of the stamp body with plasma; - glass-coating at least the side surface of the stamp body; and at least one of the steps of:

11. 11. The method according to claim 10, wherein after forming the stability layer, the region of the side surface of the stamp body (10, 10', 10'') adjacent to the stamping surface (11), in particular a region of the side surface starting from the stamping surface within a range of 1 nm to 30 nm, in particular within a range of 2 nm to 10 nm, remains free of the material of the stability layer (101).

12. The step of providing the plurality of supports (12, 12') each having one stamp body (10, 10', 10'') comprises: - providing said supports (12) each with one resting surface (120), - providing a number of stamp bodies (10) with one stamping surface (11); - attaching said stamp body (10) to said support (12); 11. The method of claim 9 or 10, comprising:

13. The step of attaching the stamp body to the support includes: - treating, in particular plasma treating, said placing surface (120) and the surface opposite said stamping surface (11); - joining the treated mounting surface (120) with the surface opposite the stamp face (11) and, optionally, drawing the material forming the stamp body from a material reservoir (100) by a moving away movement of the support (12); The method of claim 12, comprising:

14. 14. The method according to claim 9, further comprising providing the stamp body (10) on a temporary carrier (20) having an adhesion force to the stamp body that is smaller than the adhesion force between the surface of the support and the surface of the stamp body.

15. 15. The method according to any one of claims 9 to 14, wherein the material (100) of the stamp body (10) is provided in a recess in a temporary carrier (20) provided for said material, optionally having a release layer (30).

16. 16. The method according to any one of claims 9 to 15, wherein the material of the support is different from the material of the stamp body, the material of the support having a higher stiffness than the material of the stamp body.

Images