How to transfer parts

Abstract

The invention relates to a method for transferring components, in particular optoelectronic components, where at least one component is provided, which is attached to a first carrier via a support holder and has a transfer area on the opposite side of the first carrier. A light-guiding lifting element with a light output area is positioned such that the light output area faces the transfer area, and a first laser light pulse is generated, whereby the transfer material between the light output area and the transfer area is melted, whereby the light output area is bonded to the transfer area by the melted transfer material. The component is lifted and positioned above the rest area. A second laser light pulse is then generated, whereby the transfer material is melted anew and the lifting element is moved out of the transfer area before the transfer material solidifies, with the component remaining in the rest area as a result of the movement of the lifting element.

Description

[Technical field]

[0001] This invention claims priority from U.S. Patent No. 6,399,633, the disclosure of which is incorporated herein by reference in its entirety. FIELD OF THEINVENTION This invention relates to a method and assembly for transferring electronic components. [Background technology]

[0002] Various methods are known for transferring electronic components and components from a growth carrier to an auxiliary carrier or to a target substrate or circuit board. However, the increasingly smaller components, especially small optoelectronic components, make it more difficult to transfer them without errors due to various factors. With small components, the individual adhesion forces are very difficult to control, so that not all components are transferred completely during transfer. It is therefore possible that when placing the components, they still adhere to a conventional stamp pad or are not placed correctly.

[0003] For example, optoelectronic components, so-called light-emitting diodes, or even μ-light-emitting diodes with very small edge lengths, can be transferred using a type of rubber stamp. However, in this case, various attractive forces must be taken into account, which sometimes lead to incorrect or incomplete transfer. It is crucial, among other things, that the attractive forces between the stamp and the individual components must be greater than the adhesive forces of the components on the carrier, but on the other hand must be less than the adhesive forces between the components and the respective receiving areas. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] German Patent Application No. 102021118957.8 Summary of the Invention [Problem to be solved by the invention]

[0005] Thus, there continues to be a need for a method of transferring electronic components that ensures the safest handling and most accurate transfer possible.

[0006] To solve these and other problems, a method for transferring components, particularly optoelectronic components, is proposed.

[0007] In this case, at least one component is provided which is attached to the first carrier via a support holder. The component further comprises a transfer area arranged on the opposite side of the first carrier of the component. In this connection, the first carrier can be a growth substrate, an auxiliary carrier or the like, and the component is held on the first carrier via another existing support holder.

[0008] In a second step, a light-guiding lifting element is provided, which has a light output region. The light output region is positioned opposite the transfer region of the at least one component. A first laser light pulse is then generated through the light output region. The laser light pulse then has an energy input that results in local melting of a transfer material that is arranged between the light output region and the transfer region. By means of the local melting of the transfer material, the light output region is bonded to the transfer region, whereby the component is attached to the lifting element.

[0009] This tight bond then makes it possible in a next step to lift at least one component, so that it is separated from the support holder. The local melting increases the adhesion of the transfer material between the light-emitting area of ​​the lifting element and the transfer area of ​​the component, so that the component can be separated, for example broken off or pulled away, from the support holder. After lifting, the component, which is now attached to the lifting element, is again positioned above the rest area. This rest area can be part of an end carrier or can be a PCB, a rest surface for another component, etc.

[0010] After positioning the at least one component above the cradle area, a second laser light pulse is then generated through the light emission area. The transfer material is then locally melted again by the energy introduced by the laser light pulse. This reduces the adhesion between the at least one component and the transfer material in the transfer area, so that the component falls onto the cradle area or is then held by the cradle area. In the liquid state of the transfer material, the light-guiding lifting element can be moved again, so that the component remains on the cradle area. This last movement takes place before the transfer material solidifies again.

[0011] The method proposed here produces a very strong and tight bond between the lifting element and the part to be transferred, in contrast to the prior art techniques using stamp pads, which can be produced by an introduced light pulse and broken anew by a further light pulse, so that the part remains or is placed in the target position.

[0012] By using a plurality of such lifting elements, mass transfer can be easily accomplished. In addition, laser light pulses can be selectively applied to individual lifting elements, thereby selectively coupling components to the lifting elements and selectively removing such components. In this manner, components can be selectively transferred or selectively placed into still vacant locations during placement.

[0013] The method proposed herein can therefore be used in particular for the manufacture of displays or display devices and for the transfer of very small optoelectronic components, so-called μLED components with edge lengths in the range of just a few μm.

[0014] In some embodiments, the light-guiding lifting element is formed as a glass fiber through which the light pulses are emitted. The light exit surface of the glass fiber is therefore also the area where the part is attached by the transfer material. By using laser light pulses, the energy input to be introduced can be controlled, so that melting is only localized and limited to the transfer material. In that case, very short laser pulses in the range of just a few nanoseconds, for example in the range of 5ns to 20ns, generate enough energy for local melting, while being short enough to avoid heat conduction to the surrounding areas. Damage to the part due to heat generation is thereby prevented.

[0015] Another aspect relates to positioning the light guiding lifting element above or on the transfer region. In some aspects, it is contemplated that the light guiding lifting element is placed on the transfer region, such that the transfer material contacts both the light output region of the lifting element and the transfer region of the part. In this regard, it can be further contemplated that a slight force is applied by the lifting element to the transfer region during the melting process, such that the transfer material bonds intimately with both.

[0016] Alternatively, the light guiding lifting element can be positioned at a predetermined height above the transfer area, where the distance between the transfer area of ​​the part and the lifting element or transfer material is selected such that the transfer material undergoes a shape change during the melting process and thereby comes into contact with the transfer area, for example the transfer material can change into a drop shape during the melting process and thereby have an increased length and thus come into contact with the transfer area, thereby bonding the transfer area to the lifting element after the material has newly solidified.

[0017] In some embodiments, the area of ​​localized melting is smaller than the area of ​​the light exit area. In other words, localized melting occurs especially in the area where the light pulse hits the transfer material, but the energy input is so small that the area outside the area of ​​the light pulse does not melt or only melts slightly. To take particular account of this effect and to realize the benefits of this effect, in some embodiments, a special shape of the light exit area of ​​the lifting element is implemented.

[0018] The exit area can therefore be designed flat, whereby the transfer material is tightly bonded to the light exit area at this flat surface. In an alternative form, however, the lifting element is designed with a tapered tip, at the end of the lifting element the transfer material is provided. In this connection, the light pulse can be designed in such a way that it completely melts the transfer material at the lower end of the tip, whereby the transfer material forms a drop-shaped structure in its molten state. The part is captured by this drop in the transfer area, and after a new solidification, this drop-shaped transfer material bonds the part to the lifting element.

[0019] In an alternative embodiment, the light exit surface of the lifting element can be formed in a cone or hemisphere. Other possibilities would be a bowling pin tapered tip, a pyramidal tapered tip, or an inclined surface. In some embodiments, the area of ​​the light exit surface, or generally the area of ​​the tip of the lifting element, is smaller than the area of ​​the transfer area.

[0020] In some embodiments, the light guiding lifting element is positioned at a predetermined height above the transfer area, and a light pulse is subsequently generated. During the generation of the light pulse, the light guiding lifting element continues to be guided in the direction of the transfer area of ​​the component until the liquid transfer material is bonded to the transfer area. This movement can take place during the light pulse or a short time after the light pulse, the transfer material still being liquid or semi-liquid at this point, thereby allowing contact and wetting of the transfer area and bonding.

[0021] After solidification of the transfer material, the adhesive force of the transfer material in the transfer area or at the light exit surface of the lifting element is greater than the corresponding adhesive force applied to the part by the support holder, so that the part can be separated, for example broken off or pulled away, from the support element without the part becoming detached from the lifting element.

[0022] In the above-mentioned embodiment, the transfer material is arranged on the lifting element and is melted by generating the light pulse by the lifting element. In another embodiment, however, it is also possible to provide the transfer material in the transfer area before the actual transfer process. The melting of the transfer material takes place after positioning, in particular after the light exit surface has come into contact with the transfer material, so that the generated light pulse is transferred directly from the light exit surface to the transfer material, causing local melting there. This embodiment has the advantage that the transfer material can be provided or deposited in the transfer area in various ways already during the manufacturing process.

[0023] Furthermore, in this regard, it is expedient if the transfer material is also available for other steps and subsequent process steps, for example for contacting the components. In these embodiments, it may be useful if only little or no transfer material remains on the lifting element after the new melting and installation of the component on the target carrier. In these embodiments, the transfer area can therefore simultaneously form part of the contact of the component.

[0024] In another embodiment, the transfer material is a part of the lifting element, and in some embodiments, it must not remain or only remain in the transfer area of ​​the part after the transfer. In some embodiments, only a small part of the transfer material remains in the transfer area after the movement of the lifting element. This part may be less than 20% of the initial mass of the transfer material, in particular less than 10% or even less than 5% of the initial mass. In some embodiments, the loss of the transfer material on the lifting element must be as small as possible, in order to be able to carry out multiple transfer processes of the part without having to refill the transfer material on the lifting element.

[0025] In some embodiments, it may be contemplated to position a lifting element above a supply layer of transfer material to refresh the transfer material, and then an energetic light pulse is generated, which causes melting of the transfer material below the light exit surface, and the transfer material is taken up by the lifting element.

[0026] In some embodiments, it is expedient to generate a new light pulse to melt the transfer material remaining on the lifting element after the lifting element is moved. The new melting can flatten or shape the transfer material at the light exit surface as desired. This process is expedient to allow a surface as uniform as possible for a new transfer process.

[0027] A variety of different materials can be used for the transfer material to be used. For one thing, the material that is also required for further processing of the part after transfer can be used. Such use has the advantage that no severe contamination by the transfer material remaining on the part occurs, which would impair its electrical functionality. In another embodiment, the transfer material can include at least one material that also forms the transfer area of ​​the part.

[0028] Such materials are, for example, indium, gallium, nickel, silver, gold or even tin. If transparent electrical contacts, such as ITO, are used for the components, it is expedient to use tin or indium as the transfer material. Gallium can also be used well, since both indium and gallium are low-melting metals, so that the energy input, and therefore the light pulse, can be as short as possible.

[0029] In another embodiment, gold or silver can be used, since these materials are particularly suitable for the surface treatment of the contact surfaces and for producing contacts that can be soldered well.

[0030] Alternatively, thermoplastics or silicones can also be used as transfer materials. These are characterized in particular by a residue-free lifting method, in which little or only a small amount of transfer material remains in the transfer area of ​​the component. In that case, the intensity and the length of the light pulse are set to the transfer material to be used and are selected so that only the amount of transfer material necessary to overcome the adhesive forces of the component on the first carrier is melted.

[0031] Another aspect relates to a transfer assembly having a plurality of glass fiber lines, at the end of which there is a light exit surface. In that case, each glass fiber line is selectively connected to a light generating assembly that generates laser pulses of just a few nanoseconds. In that case, the distance and shape of the plurality of glass fiber lines are selected to be particularly suitable for receiving the parts. A meltable transfer material is disposed on each of the light exit surfaces of the glass fiber lines. In addition, the transfer assembly comprises a moving device that is capable of moving the glass fiber line both vertically and horizontally. According to the invention, the transfer assembly is designed to position the light exit surface of the glass fiber line above the transfer area of ​​each of the plurality of parts, and to subsequently selectively or jointly generate a plurality of laser light pulses to melt the transfer material on the light exit surface of the glass fiber line.

[0032] In some embodiments, the transfer assembly is then designed to perform a vertical movement during the generation of the multiple laser light pulses and thereby apply a force to the surface of the transfer area by the glass fiber line, the force being selected such that the molten transfer material creates a bond between the end of the glass fiber line and the respective transfer area of ​​the part without damaging the part or removing it from the support holder.

[0033] In some embodiments, for vertical alignment, a laser interferometer or other interferometer is provided, which controls the vertical movement of the glass fiber line by coupling. In this way, particularly precise positioning in the vertical direction above the component is possible. Alternatively, it can also be controlled by capacitance measurement between the component and the glass fiber.

[0034] In that case, the light generating assembly is designed to generate laser light pulses in the range of just a few nanoseconds, for example in the range of 5-30 ns.

[0035] Other aspects and embodiments according to the proposed principles will become apparent in connection with the various embodiments and examples described in detail with reference to the accompanying drawings. [Brief description of the drawings]

[0036] [Figure 1] FIG. 2 shows a first step of the part transfer method according to the proposed principle. [Diagram 2] FIG. 13 illustrates another aspect of the part transfer method according to the proposed principle. [Diagram 3] 1 shows a cross section of an embodiment of the tip of a fiberglass line that can be used to transfer parts according to the proposed principle. [Figure 4] FIG. 13 shows another exemplary embodiment of a part transfer method according to the proposed principle. [Diagram 5] FIG. 13 is a detailed view of the transfer material separation process. [Figure 6] 1 is an exemplary embodiment of a transfer assembly according to the proposed principles. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] The following embodiments and examples show various aspects and their combinations according to the proposed principles. The embodiments and examples are not necessarily drawn to scale. Various elements may be drawn enlarged or reduced in size to highlight individual aspects. It is to be understood that individual aspects and features of the embodiments and examples shown in the figures can be combined with one another without compromising the principles according to the invention. Some aspects have regular structures or shapes. It should be noted that in practice, slight deviations from the ideal shapes may occur without going against the ideas according to the invention.

[0038] 1 and 2 show, in their respective subdivisions, FIGS. 1a and 1b and 2c-e, various method steps for transferring electronic components according to the proposed principle.

[0039] In this exemplary embodiment, the component 2 is designed as an optoelectronic component, a so-called μ-light-emitting diode. However, it is also possible without problems to transfer other components, for example based on silicon, or other optoelectronic components in this way. To this extent, the optoelectronic components described here should be understood as merely an example.

[0040] The component comprises a semiconductor stack 50 consisting of various semiconductor layers 53, 54 and 55 and is designed as a vertical light-emitting diode with a rear terminal contact 52 and an upper terminal contact 40. The upper terminal contact 40 is at the same time a transfer area 41 with which the component is subsequently transferred to an end carrier.

[0041] In the illustrated embodiment, the component 2 is connected to the carrier substrate 60 via a support holder 61. As shown, the lower contacts 52 are spaced apart from the surface of the substrate carrier 60, so that the component 2 rests only on the support holder 61. In the embodiment illustrated here, two support holders 61 are provided. These support holders, which abut the edge of the component, are also suitable for supporting other components, not shown here, arranged next to them.

[0042] However, it is also possible to provide only one support holder with components attached, either centrally or offset. In some exemplary embodiments, such a support holder can also be omitted if the adhesion forces between the bottom layer of the component and the carrier substrate 60 are smaller than the subsequent adhesion forces after melting and bonding of the transfer material. However, to avoid high defect densities and the associated functional failures, care must be taken not to damage the component during subsequent lifting out due to this, in particular to ensure that the individual layers remain intact.

[0043] The transfer device 1 according to the proposed principle comprises a light generating device 10 for providing laser pulses with a settable intensity and a settable duration. A number of glass fiber lines 20 are connected to the light generating device 10, one of which is shown here as an example. The glass fiber line 20 comprises a length and a width "d" which in the example embodiment is smaller than the width of the corresponding transfer area 41. For an edge length of the μLED in the range of 10 μm to 20 μm, the width of the tip of the glass fiber line can be, for example, about 5 μm. A certain area ratio is derived therefrom. It has turned out to be useful in some applications if the area of ​​the tip of the glass fiber line or of the lifting element is in the range of 20% to 40% of the area of ​​the transfer area. Larger areas are also possible, but it must then be ensured that the slightest mispositioning does not lead to the glass fiber line coming into contact with adjacent components.

[0044] At the bottom and at the tip of the glass fiber line 20 there is a light exit surface 24. The light exit surface is provided with a transfer material 30. The height "h" of the transfer material is selected such that the transfer material can be melted by the introduced light pulse, but does not or only slightly changes its shape. In this exemplary embodiment, the contact 40 is designed as an ITO, i.e. indium tin oxide, transparent conductive contact. Indium is also contemplated as the transfer material 30, whereby both the contact area 40 or transfer area 41 and the transfer material 30 have the same or similar material.

[0045] 1b, the first step of the transfer method is now shown in detail. In this case, a glass fiber line 20 with a light exit surface is guided towards the component, so that the transfer material 30 comes into contact with the transfer area 41 of the component. During this step, vertical control and regulation is performed by a control circuit (not shown) of the transfer device 1, which determines the height by means of a suitable feedback loop. For example, the height up to which the transfer material 30 comes into contact with the transfer area 41 can be determined by interference measurement. Alternatively, a capacitance or resistance measurement between the transfer material 30 and the transfer area 41 of the component is also possible. In this way, the distance can be determined precisely and excessive lowering and therefore damage to the component can be avoided.

[0046] After the transfer material comes into contact with the transfer area 41, a laser light pulse is generated by the light generating device 10, which then locally supplies the transfer material with energy. The laser light pulse results in local heating and melting of the transfer material 30 in the area of ​​the light exit surface. The laser light pulse is then selected to be short so that a relatively long energy transmission and in particular heat conduction to the transfer area and the component located below is largely avoided. The local melting then bonds the transfer material 30 to the transfer area 41 on the one hand and to the light exit surface of the glass fiber line 20 on the other hand. In other words, the melted transfer material forms a bridge between the tip of the glass fiber line 20 and the transfer area 41. The melted transfer material solidifies again immediately after the laser light pulse and forms a tight bond between the tip of the glass fiber line 20 and the component 2.

[0047] Then, in the next step of the proposed method shown in Fig. 2c, the fiberglass line together with the part connected to it is moved upwards, thereby separating the part 2 from the support holder 61. In that case, the adhesion of the transfer material 30 with the transfer area 41 and the fiberglass line 20 is greater than the corresponding adhesion of the support holder 61 on the part.

[0048] A transfer process then takes place in which the component is positioned above another carrier 70 and the contact area 71 arranged thereon in the split diagram 2d. After positioning, the component is lowered again until it contacts the contact area 71, again with its contact area 52. In addition to that, the component can then be lightly pressed against the contact area 71 by the transfer device, whereby a light contact is already made. The contact area 71 can have the same material as the contact area 52, but can also comprise a solder paste or a similar material. In particular, this material can comprise a soft material, whereby the component 2 is pressed into the contact area 71 by a slight vertical downward movement, whereby a good bond is already achieved.

[0049] In the next step, further laser light pulses are then generated in the glass fiber line 20, which melts the transfer material 30 anew. At the same time, as shown in the partial view of FIG. 2e, an upward movement direction of the glass fiber line 20 and, optionally, of the light-generating device 10 occurs, so that the glass fiber line 20 together with the transfer material 30 adhering thereto is separated and lifted out of the transfer area 41. In this case, the adhesive forces between the now molten transfer material 30 and the transfer area 41 are smaller than the corresponding adhesive forces between the soft contact material 71 and the contact element 52. In this way, the component remains in the contact area 71.

[0050] Alternatively, the component can be aligned slightly above the target position and the laser light pulse can then be generated, in which case the component drops slightly after the melting process onto the end carrier, which can then be attached. In both variants, a reliable transfer of the component to the target substrate 70 and contact areas 71 is ensured.

[0051] As shown in Fig. 2e, the transfer material 30 remains on the glass fiber line 20. In that case, it must be ensured that the adhesion of the transfer material 30 in the molten state at the light exit surface of the glass fiber line 20 is greater than in the transfer area 41. In this way, the molten transfer material can be removed from the transfer area 41, so that only a small residue remains in the transfer area. With proper use of the transfer material, this residue is not problematic for further processing of the transfer area 41' and can even be used for further processing depending on the transfer material used.

[0052] However, in order to allow as many transfer processes as possible with the same glass fiber line and the same transfer material, it is expedient to consume as little transfer material as possible in the process, i.e. to leave it on the surface of the transfer area 41'. In this connection, it can therefore be advantageous to coordinate the vertical movement with the generation of the light pulses, thereby simultaneously moving the glass fiber line 20 upwards during local melting.

[0053] FIG. 3 shows a possible embodiment of the tip of a glass fiber line 20 for transferring parts. In FIG. 3a on the left, the glass fiber line 20 is formed with a hemispherical tip 23, which extends in cross section in a semicircular shape as shown. In this case, this hemispherical tip 23 is provided with a transfer material 31. When melted, the transfer material forms a small drop shape, which causes the melting process to slightly increase the height of the transfer material. The tip can also be positioned slightly (just a few nm) above the transfer area and does not have to be in contact with the transfer area. In an alternative embodiment, the tip can also be moved somewhat downward during the melting process, which increases the contact area of ​​the transfer material to the transfer area and the material substantially fills the intermediate space between the hemispherical tip and the transfer area.

[0054] Besides the spherical shape of the tip 23, lens shapes or other forms are also possible, in particular other contour shapes of the surface of the tip, whereby the light can for example be made more focused or divergent, in order to make it possible to control the melting process to a certain extent.

[0055] In the middle split Fig. 3b, the tip of the glass fiber line is formed into a cone shape, so that the melted transfer material 31 collects as a drop at the tip of the glass fiber line. This makes it easier to control the amount of transfer material, and the melting process allows the structure of the transfer material and the shape of the drop to be changed. Thus, this embodiment allows the tip of the glass fiber line 20 to be positioned above the transfer area, and the transfer material 31 to be subsequently melted, so that the transfer material forms a bridge between the tip of the glass fiber line and the transfer area.

[0056] The right split view shows another embodiment in which the end 22 of the fiberglass line 20 is curved inwards. In this case, the transfer material fills this recess and forms a flat, smooth surface. In the transfer process with this tip, the fiberglass line is lowered onto the part and the transfer area 41, and the transfer material in the recess is subsequently melted. The transfer material then bonds to the transfer area, so that the part can be lifted after solidification of the transfer material. Such a form of the fiberglass tip is advantageous if the adhesion forces between the fiberglass tip and the transfer material and between the transfer material and the transfer area are approximately balanced. The larger surface area at the fiberglass tip allows a larger force to be applied to the transfer material, which remains at the tip after the lifting process.

[0057] Depending on the different adhesion forces, melting processes and the form of the transfer process, different residues can form on the surface of the transfer area. Lifting processes can also result in the transfer material being pulled off or detached, but precisely because of this, these areas require a special combination and setting of the various parameters. On the other hand, this method precisely makes it possible for the various parameters to be adjusted to one another.

[0058] The parameters can be, among others, the temperature of the transfer material, the viscosity of the transfer material upon melting, and the speed of the movement, i.e. vertical movement, in both the first and second melting processes. The choice of the transfer material and the different surface properties of the transfer and light exit areas can also play a role in this process. Split Fig. 5a-c shows different stages of such a lifting process to illustrate some aspects of the proposed principle.

[0059] In the split FIG. 5a, a part of the transfer area of ​​the component is shown after it has been transferred and placed on the target substrate. The component is then connected to the light exit surface 24 of the glass fiber line 20 via a material bridge of the transfer material 30. As shown in this exemplary embodiment, the adhesion area of ​​the transfer material 30 in the transfer area 41 and the adhesion area of ​​the light exit surface 24 are approximately the same size. Then, as shown in the split FIG. 5b, the glass fiber line is slightly displaced after liquefaction of the transfer material 30 by a second melting process. Due to the higher adhesion between the transfer material 30 and the surface of the light exit surface 24, most of the material 30 remains on the glass fiber line, so that a constriction 35 is formed between the surface of the transfer area 41 and the transfer material 30. This constriction is characterized by a smaller amount of material. In a next step, the contact area 71 on the target substrate is further soldered or otherwise attached to the contact 52. This step can also be performed when a bond still exists between the fiberglass line 20 and the transfer area 30, possibly with the advantage that the components are held in place by the fiberglass line during the soldering or bonding process.

[0060] With increasing distance of the glass fiber line from the surface of the transfer area 41, the constriction 35 becomes stronger until it finally breaks away and a solidifying drop of the transfer material 30 is present at the light exit surface 24 of the glass fiber line 20. Only very small residues 36 of the transfer material remain on the surface of the transfer area 41. These only play a secondary role for the further processing of the surface of the transfer area and can therefore be removed by a corresponding cleaning process.

[0061] With a suitable selection of the transfer material 30, residues can be completely or almost completely avoided. With a suitable selection, it is also possible to use the residues in further processing, if necessary. For example, if gold or silver is used as a material for contacts in the transfer area, it is conceivable to use these also as transfer material.

[0062] 4A-4C show another exemplary embodiment of the method for transferring an electronic component according to the proposed principle. In contrast to the exemplary embodiment described above, in this embodiment the transfer material 30 is not present on the light exit surface of the glass fiber line 20 but on the electronic component 2 itself. This embodiment has the advantage that the transfer material can already be provided in the transfer area 41 during the production of the component 2 and is available for further processing steps after the transfer. The component 2 is coupled to the carrier 60 via a support holder 61. In this exemplary embodiment, the support holder 61 is arranged in the center, so that the component is held on the carrier 60 substantially only by the support of the holder 61. In that case, the sacrificial layer between the component 2 and the carrier substrate 60 has been removed.

[0063] As in the above-mentioned exemplary embodiment, the transfer device comprises a light generating device 10 and a fiberglass line 20 with a tip connected to the light generating device. In this exemplary embodiment, the transfer device is formed in an elliptical shape. For the transfer process, the fiberglass line 20 is moved towards the part and the transfer material placed in the transfer area is moved until the tip 24 lightly touches it. For precise positioning, as in the above-mentioned exemplary embodiment, capacitance or interference measurements can also be used.

[0064] After the tip 24 of the fiberglass line is correctly positioned above the transfer material 30, a laser light pulse is generated, which is emitted via the light exit surface. At this point, the transfer material 30 melts and is slightly pulled towards the tip of the fiberglass line 20 by adhesive forces. The laser light pulse is switched off, whereby the transfer material 30 solidifies and forms a spherical bump 36, shown in the split Fig. 4B. The component can then be removed from the support holder 61 and transferred to the target substrate 70. The component is placed in the contact area 71 of the target substrate 70, as shown in Fig. 4c), and is slightly pressed into this target substrate. A second light pulse is then generated, which melts the transfer material anew. During the second melting process, and while the transfer material is still liquid, the fiberglass line 20 is moved slightly upwards, which causes the transfer material to flow out of the tip 24 of the fiberglass line and remain on the component. After the transfer material has completely cooled, only a slight bump may remain in the area 36'. The use of an elliptical surface allows the transferred material to flow back onto the part again during the second melting process, leaving very little material on the light exit surface.

[0065] The process presented here can be applied to multiple electronic components and is easily scalable. In this way, mass transfers of components from a wafer can be performed. During the transfer, it is also possible to only selectively place components on the carrier substrate by a second light pulse, so that the method also offers correction possibilities. For example, a component can be selectively moved to an unpopulated position and placed in this position by a new laser light pulse.

[0066] By means of additional light pulses, the used glass fiber line can be cleaned of excess transfer material. On the other hand, it is also conceivable to precisely apply this transfer material to the optical fiber anew. For this purpose, the tip of the glass fiber line is positioned above a material reservoir, and the material is then locally melted there. The glass fiber is then submerged in the liquid transfer material, so that the material remains at the tip and at the light exit surface.

[0067] By generating light pulses of different intensities and lengths, the energy input to the transfer material can be controlled. Furthermore, it is conceivable to provide different materials for the various components to be transferred, thereby achieving an overall high flexibility.

[0068] FIG. 6 shows a schematic representation of an embodiment of a transfer device. This transfer device comprises, as already explained, a number of glass fiber lines 20, the spacing of which is selected so that it corresponds to the spacing of the parts to be transferred. As shown in the exemplary embodiment, the glass fiber lines can also be controlled individually but also together by the light generating device 10. Thus, to this extent, it is possible to selectively receive or place parts. The tips of the glass fiber lines are appropriately shaped. In some embodiments, the glass fiber lines can also be exchanged, so that different tips can be transferred depending on the size of the parts. In general, the area of ​​the tips of the glass fiber lines is smaller than the area of ​​the transfer area, in this way ensuring that even in the case of slight deviations, the glass fiber lines are still positioned in or above the transfer area and in particular do not come into contact with adjacent parts.

[0069] The transfer device comprises a movement unit 60, by means of which the individual glass fiber lines can be moved both in their vertical direction and in their horizontal direction. In this respect, the movement unit 60 can comprise step motors or even piezoelectric elements for the vertical and horizontal movement. For the corresponding control, a control / control circuit 70 is provided, which is coupled both to the movement device 60 and to the individual light-generating devices 10.

[0070] The control / control circuit 70 can include multiple feedback loops and sensor systems to enable precise positioning and alignment. In this regard, the vertical positioning can be set by capacitance, resistance or even interference measurements. For this purpose, the wafer with the components to be transferred and the target wafer can be provided with corresponding reference points and measurement points for the laser. In the case of capacitance measurements, a potential can be applied to the wafer and the electronic components present thereon, either together or separately, so that the distance between the light exit surface and the surface of the components and the transfer area can be determined. [Explanation of symbols]

[0071] 1. Teleportation Device 2 parts 10 Light generation device 21, 22, 23 Tip 20 Lifting Elements 24 Light exit surface 30 Transfer materials 31 Transfer materials 36, 36' residue 37 40 Contact 41 Transfer area 50 layer rows 53, 54, 55 layers 52 Contacts 60 Substrates 61 Support holder 70 Target Board 71 Contacts

Claims

1. 1. A method for transferring a part, comprising: - providing at least one component attached to a first carrier via a support holder, said at least one component having a transfer area on an opposite side of said first carrier; - positioning a light guiding lifting element having a light exit surface, said light exit surface facing said transfer area; - generating a first laser light pulse passing through a light output region; - locally melting the transfer material present between the light exit surface and the transfer area by means of the first laser light pulse; - bonding said light exit surface to said transfer area by said molten transfer material; - a lifting step of said at least one component, in which said at least one component is separated from said support holder; - positioning said at least one component above a cradle area; - the transfer material is newly melted by generating a second laser light pulse through the light exit surface; - removing the light guiding lifting element from the transfer area before the transfer material solidifies, so that the part remains in the cradle area; A method comprising:

2. The method of claim 1 , wherein the first pulse of laser light and the second pulse of laser light are generated along the light guiding lift element.

3. The method of claim 1 , wherein the duration of the first laser light pulse and / or the second laser light pulse is in the range of 1 ns to 500 ns.

4. The positioning step includes: - placing the light guiding lifting element on the transfer area such that the transfer material is in contact with both the light exit surface and the transfer area, or - positioning said light guiding lifting element at a predetermined height above said transfer area such that said transfer material contacts said transfer area due to a shape change caused by said localized melting during a first laser light pulse, The method of claim 1 , comprising:

5. The method of claim 1 , wherein the localized melting is performed in an area smaller than an area of ​​the light exit surface.

6. The method of claim 1 , further comprising applying a force to the transfer region with the light guiding lifting element during generation of the first laser light pulse.

7. 2. The method of claim 1, wherein the bonding step is performed by the molten transfer material re-solidifying after generation of the first laser light pulse, and an adhesive force of the transfer material in the transfer area and / or the light exit surface is greater than a holding force applied to the at least one component by the support holder.

8. The method of claim 1 , wherein the step of providing the at least one component comprises providing the transfer material in the transfer area.

9. The method of claim 1 , wherein the transfer material comprises a material that is a portion of the material of the transfer region.

10. The method of claim 1 , wherein the transfer region forms at least a portion of a contact of the component.

11. The method of claim 1 , wherein only a portion of the transfer material remains in the transfer region after the light guide lifting element is moved.

12. The method of claim 1 , further comprising the step of freshly melting the transfer material at the light exit surface by generating a laser light pulse for surface shaping of the transfer material.

13. The transfer material may be any of the following materials: -indium, -gallium, -nickel, -silver, -gold, - Tin, The method of claim 1 , comprising at least one of:

14. The method of claim 1 , wherein the light guiding lifting element comprises glass fibers, ends of the glass fibers forming the light exit surface.

15. The method of claim 1 , wherein the area of ​​the light exit surface is in the range of less than 75% of the area of ​​the transfer region.

16. The method of claim 1, further comprising the step of soldering a second contact to the receiving area, wherein the light-guiding lifting element remains coupled to the transfer area via the transfer material during the soldering process.

17. The tip of the light guide lifting element has the following shape: - hemispherical tip, - a conical tip, - a bowling pin shaped tip, - inwardly curved recesses, The method of claim 1 , further comprising one of:

18. A transfer assembly comprising: a light generating device for generating a first pulse of laser light and a second pulse of laser light, a light guiding lifting element having a light exit surface; a movement device designed to position the light exit surface of the light-guiding lifting element above a transfer area of ​​a component and to move the light-guiding lifting element vertically, - to bond said component to said light guiding lifting element by a transfer material melted by said first laser light pulse in said transfer area; and a transfer assembly, which is adapted to release said coupling by said transfer material again after transfer by a second laser light pulse.

19. The transfer assembly of claim 18, wherein a duration of the first laser light pulse and / or the second laser light pulse is in the range of 1 ns to 500 ns.

20. 20. The transfer assembly of claim 18, wherein the area of ​​the light exit surface is in the range of less than 75% of the area of ​​the transfer region.

21. 20. The transfer assembly of claim 18, wherein the transfer assembly is designed to apply a force to the transfer region by the light guiding lifting element during generation of the first laser light pulse.

22. one or more sensors for detecting the distance between a cradle area and said light exit surface, or a value derived from said distance; a control / control circuit coupled to said one or more sensors and to said displacement device for controlling vertical displacement in response to signals of said one or more sensors; The transfer assembly of claim 18 further comprising:

23. The tip of the light guide lifting element has the following shape: - hemispherical tip, - a conical tip, - a bowling pin shaped tip, - inwardly curved recesses, 20. The transfer assembly of claim 18, comprising one of:

24. The transfer assembly of claim 18 , wherein the light exit surface is covered by the transfer material.

25. 20. The transfer assembly of claim 18, further comprising a transfer material reservoir for supplying a transfer material to the light exit surface.

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