Method for placing and securing at least one micromirror matrix

Abstract

The invention relates to a method for placing and securing at least one MMA array (10) and / or at least one sub-group (80) thereof on a support layer (18), having the following steps: a) positioning the at least one MMA array (10) or the at least one sub-group (80) thereof on a grid structure (46) of a handling device (40, 42); b) aligning the at least one MMA array (10) or the at least one sub-group (80) thereof positioned in step a) by means of a joining aid (54) which can be retracted into the handling device (40, 42); c) lifting the handling device (40, 42) and lifting up the at least one MMA array (10) and / or the at least one sub-group (80) thereof aligned in step b) from the joining aid (54); d) depositing the at least one MMA array (10) and / or the at least one sub-group (80) thereof onto a support surface (19) provided with an adhesive layer (78); and e) detaching and laterally removing the grid structure (46) made of cutouts (58) and / or gaps (64) below the at least one MMA array (10) or the at least one sub-group (80) thereof.

Description

[0001] Description

[0002] title

[0003] METHOD FOR PLACING AND FASTENING AT LEAST ONE MICROMIRROR MATRIX

[0004] Technical area

[0005] The invention relates to a method for placing and securing at least one MMA assembly and / or at least a subgroup thereof on a carrier layer. Furthermore, the invention relates to a handling device with a joining aid for placing and securing at least one MMA assembly or at least a subgroup thereof, as well as to an MMA support surface equipped with at least one MMA assembly, and to the use of the method for placing and securing at least one MMA assembly and / or at least a subgroup thereof on the carrier layer.

[0006] State of the art

[0007] EP 3 333 882 A1 discloses a method for bonding thin chips to a target substrate. According to this method, an adhesive tape with thin chips mounted thereon is provided. The chips are transferred to a carrier substrate through one or more tape-to-tape transfer steps. The carrier is then cut into individual carrier-chip assemblies, which can be machined with existing tools designed for processing chips of normal thickness. The chips can then be bonded to the target substrate.

[0008] EP 2 284863 A1 discloses an apparatus and method for handling semiconductor chips in a pick-and-place process. A chip handling tool is configured to pick up a chip at a receiving location and transfer it to a delivery location, for example, to a second chip handling tool, which places the chip on a substrate. Thin vacuum channels are used for this transport to temporarily hold the chip. Illumination is used to identify defects.

[0009] WO 96 / 26875 A1 discloses an approach to transport components, such as lead frames, along a rail using compressed air as part of a semiconductor chip manufacturing process.

[0010] When manufacturing MEMS components, such as mirror arrays, customers often require the highest possible optical fill factor. In this context, optical fill factor means that the side of a Micro Mirror Unit (MMU) facing a process chamber should be covered as completely as possible with individual mirror elements. This customer requirement conflicts with the processability of these components using conventional handling solutions within a pick-and-place process, with which the MMA (Micro Mirror Array) assemblies, comprising a MEMS + FE-ASICs, are to be joined to a support plate. Since touching the individual mirror elements is prohibited to avoid damage, a touchable frame surrounding the mirror array appears necessary from the perspective of conventional handling concepts.However, the area of ​​this handling frame would have a detrimental effect on the optical fill factor to be achieved.

[0011] Gripping a frameless MMA from the side for placement on the support plate is conceivable, but would only be applicable if only a single MMA were to be placed on the support plate. This MMA would, however, be designed so large that it would be almost congruent with the support plate and would, for example, comprise 24 x 24 mirror elements. For reasons of manufacturability, however, it is assumed that segmentation of an MMA will be necessary, so that the support plate will be occupied by a plurality of smaller, closely spaced MMAs, for example 2 x 2 MMAs, each of which can contain 12 x 12 mirror elements. In such a divided configuration, the side surfaces of the individual MMA assemblies are not suitable for the placement process on the support plate. MMAs placed first would act as an interfering contour when attempting to place further MMAs.These could not be placed because the gripping tool touching from the side would collide with the previously placed MMAs.

[0012] A backward gripping or suctioning of M MA assemblies using a vacuum gripper also does not appear suitable, since this is the joining surface, i.e. the surface that is to be brought into contact with the support plate.

[0013] From the above considerations, it follows that for frameless MMA assemblies in a split design, neither the front side, where the mirror plane is located, nor the side surface, nor the back side, which represents the electrical contact plane of the FE-ASICs, are suitable for contacting with conventional handling tools, such as mechanical grippers or pneumatic suction elements. Therefore, a new handling device or method is required.

[0014] Disclosure of the invention

[0015] According to the invention, a method for placing and equipping at least one MMA assembly and / or at least one subgroup thereof on a carrier layer is proposed, wherein the following method steps are carried out: a) Positioning the at least one MMA assembly or the at least one subgroup thereof on a network structure of a handling device, b) Aligning the at least one MMA assembly positioned according to method step a) or the at least one subgroup thereof by means of a joining aid that can be inserted into the handling device, c) Lifting the handling device and removing the at least one MMA assembly or the at least one subgroup thereof aligned according to method step b) from the joining aid,d) placing the at least one MMA assembly or the at least one subgroup thereof onto a support surface provided with an adhesive layer to form a material-locking connection and e) severing and laterally removing the mesh structure from recesses and / or gaps below the at least one M MA assembly or the at least one subgroup thereof.

[0016] The procedure proposed according to the invention advantageously enables the handling of highly sensitive MMA assemblies, in particular their placement in an adhesion layer forming a material-tight connection. The support surface is provided with a still pasty joining material, which can be, for example, solder paste or an isotropically electrically conductive adhesive (silver particles dissolved in an epoxy matrix) or an anisotropically conductive adhesive. This joining material is structured, i.e., not applied over the entire surface, in order to keep the electrical signal lines insulated from one another. When placing or setting down the at least one MMA assembly or at least one sub-assembly thereof on the joining material, no lateral movement must occur, as this would smear the joining material.

[0017] In an advantageous development of the method proposed according to the invention, the at least one MMA assembly or the at least one subgroup thereof is inserted into an adhesion layer provided as a pre-printed solder paste according to method step d).

[0018] The method proposed according to the invention provides that the at least one MMA assembly or at least one subgroup thereof is aligned using the joining aid before being picked up by the handling device, without contact with the handling device. This allows for more precise production of predefined positions of the individual MMA assemblies or subgroups thereof.

[0019] Furthermore, the method proposed according to the invention advantageously provides for a lateral alignment of the at least one MMA assembly or at least one sub-assembly thereof on the joining aid to be carried out with pneumatic support. This advantageously provides the possibility of making position corrections before the handling device takes over the finally aligned at least one MMA assembly and / or the at least one sub-assembly thereof. Furthermore, the method proposed according to the invention advantageously provides for the handling device and the joining aid to be aligned relative to one another using indexing pins and openings complementary to these, in method step b).

[0020] In the method proposed according to the invention, after performing method step b), the handling device is lifted, and the at least one MMA assembly or at least one subgroup thereof is taken over by the handling device, while maintaining the previously defined alignment. This enables highly precise placement of the individual MMA assemblies or at least one subgroup thereof on the adhesion layer in the form of the pre-printed solder paste.

[0021] Furthermore, the method proposed according to the invention advantageously provides that, after performing method step d), a reflow soldering process is carried out, according to which the at least one MMA assembly or at least one subgroup thereof is bonded to the support surface. For reflow soldering, for example, the vacuum vapor phase soldering variant can be used, or alternatively, a combination of IR and convection soldering, in this case preferably under a nitrogen atmosphere. If conductive adhesives are used, a simple oven process can also be used to cure these adhesives.

[0022] Furthermore, the invention relates to a handling device with a joining aid for placing and fastening at least one MMA assembly or at least a subgroup thereof on the support surface for carrying out the above-mentioned method, wherein a mesh structure comprises a first group of wires and a second group of wires that form a positioning plane. This facilitates the handling of MEMS components, in particular MMA assemblies, by only contacting their rear side, while the top and side surfaces remain essentially free.

[0023] In an advantageous development of the handling device with joining aid proposed according to the invention, the first group of wires and / or the second group of wires run at right angles or diagonally to one another. The arrangement of the first and second groups of wires or the individual wires depends on the shape of the FE-ASICs. Semiconductor chips are almost always rectangular, which recommends an essentially rectangular arrangement of the individual wires of the first and second groups of wires. Since a high fill factor is also required here, only those FE-ASIC chip shapes that allow Platonic tessellation are considered. In addition to the rectangle, these are the triangle and the hexagon. The wire guide could also be designed so that the individual wires of the first and second groups of wires only need to be guided along the chip sides. Hexagonally configured chips can also be used.

[0024] In an advantageous development of the handling device with joining aid proposed according to the invention, the first and second groups of wires each comprise individual wires whose cross-sections are smaller than the width of the recesses on the top side of the joining aid. This ensures that the first and second groups of wires forming the mesh structures are inserted into the recesses and contact the MMA assemblies or sub-assemblies placed on the joining aid exclusively on their underside.

[0025] In an advantageous development, the handling device including the joining aid is designed such that it comprises clamping devices for the first and second group of wires as well as alignment aids. Adaptive alignment can advantageously be achieved using the alignment aids. A suitable camera system can, for example, record the position of the joining aid. A target / actual deviation is then determined using logic; furthermore, the joining aid is moved via a kinematics. For this purpose, the joining aid can be provided with "fiducials," i.e. markings intended to carry out automated detection and localization, for example precisely etched cross or circle patterns. In addition, the joining aid has suitable stop and gripping surfaces for contacting the kinematics. In the case of positive joining, indexing pins and matching holes can function as alignment aids.

[0026] Furthermore, the handling device and joining aid must be designed to be suitable for cleanroom production. With regard to material selection, care must be taken to avoid contamination through abrasion. Furthermore, the joining aid or handling device is made of a material with a low coefficient of thermal expansion to ensure accuracy. Furthermore, sufficient rigidity is required to prevent deviation from the optimal shape due to deflection.

[0027] Furthermore, the invention relates to an MMA support surface equipped with at least one M MA assembly and / or a subgroup thereof, wherein the MMA support surface is equipped with a number of frameless MMA assemblies and / or at least one frameless subgroup thereof.

[0028] Finally, the invention relates to the use of the method for placing and fastening at least one MMA assembly and / or at least a subgroup thereof on a support surface and forming a material-to-material connection to the support surface.

[0029] Advantages of the invention

[0030] The solution proposed by the invention advantageously achieves the following: by means of a handling device according to the invention with a joining aid, which utilizes the topography of an MMA assembly or a subgroup thereof, particularly for frameless MMA assemblies, the assembly can be precisely picked up, positioned, aligned, and placed on a support surface. For example, an adhesion layer in the form of a pre-printed solder paste can be applied to the support surface, so that cohesive connections can subsequently be formed using a soldering process, in particular reflow soldering.

[0031] The solution proposed according to the invention avoids, in particular, contact with unsuitable surfaces, such as the lateral surfaces of the MMA assemblies or their surface during processing.

[0032] The solution proposed according to the invention allows frameless MMA assemblies to be processed in a partitioned configuration, i.e., in subgroups. This allows the requirements of a very high optical fill factor, which is inherent in a frameless design requirement, to be met, as well as the need for smaller MEMS production. The solution proposed according to the invention makes it possible, in particular, to produce partitioned MEMS dies. MEMS are microelectromechanical systems, in this case dies (chips) manufactured from silicon using semiconductor technology. An MEMS die is understood to be a chip on which several actuatable micromirrors are arranged in an array.

[0033] Furthermore, the solution proposed by the invention allows all MMA assemblies or subassemblies to be placed, particularly on a support surface, which can be done simultaneously. This improves the positioning accuracy of the individual MMA assemblies or subassemblies relative to one another and also offers advantages in terms of the achievable cycle time.

[0034] Short description of the drawings

[0035] Embodiments of the invention are explained in more detail with reference to the drawings and the following description.

[0036] They show:

[0037] Figures 1 - 1.2 an MMA assembly using the example of a frameless MEMS die in front and back view,

[0038] Figures 2 and 2.1 MMA assemblies with different designs,

[0039] Figure 3 shows a support surface equipped with MMA assemblies,

[0040] Figures 4 and 4.1 show a handling device in side view and top view,

[0041] Figures 5 and 5.1 show a joining aid for aligning MMA assemblies to each other and to the handling device in side view and top view,

[0042] Figures 6 - 6.2 show the joining aid retracted into the handling device in side view and top view, Figures 7 - 7.2 show the joining aid with inserted handling device and pre-positioned M MA assembly,

[0043] Figures 8 - 8.2 show a state after a positive connection of the MMA assemblies to the support surface,

[0044] Figures 9 and 9.1 Steps for removing the handling device after establishing the material connection,

[0045] Figure 10 shows a side view of an MMA assembly after completion of the joining process,

[0046] Figure 10.1 is a plan view of the representation according to Figure 10,

[0047] Figure 10.2 is a perspective view of the representation according to Figure 10 and

[0048] Figure 10.3 is a side view of the MMA assembly as shown in Figure 10.

[0049] When developing MMUs (Micro Mirror Units), the aim is to achieve the highest possible optical fill factor. In the present context, optical fill factor means that the sides of the MMU facing a process chamber should be covered as completely as possible, for example with mirror elements. However, these are difficult to join to a support surface 19 using conventional handling solutions, such as a pick-and-place process with which an MMA assembly comprising MEMS + FE-ASICs can be handled. This is due to the fact that, for example, when using mirror elements, contact is prohibited to avoid damage. Even if, as shown in Figure 2, a circumferential handling frame 24 were used, the mere presence of the circumferential handling frame 24 would have a detrimental effect on the optical fill factor.

[0050] Figure 1, for example, shows a front side 14 of an MMA assembly 10 constructed from individual mirrors 12. Instead of individual mirrors 12, other individual elements of an MMA assembly 10 could also be used. Figure 1.1 shows a side view of the illustration according to Figure 1 with ASIC components 20 arranged on a carrier layer 18 (MEMS die). Figure 1.2 shows a rear side 16 of the MMA assembly 10, from which it can be seen that contacts 22 are located on the rear of the individual ASICs 20.

[0051] Figure 2 shows a circumferential handling frame 24, which, as described above, negatively influences the optical fill factor. Figure 2.1 shows a frameless design of an MMA assembly 10 from the front side 14. Reference numeral 18 denotes a carrier layer (MEMS die) on which, in this embodiment, the individual elements 12, here designed as individual mirrors, are placed. It is assumed that segmentation of an MMA assembly 10 will be necessary, so that a support surface 19 is populated with a plurality of smaller MMA assemblies 10 to be placed closely next to one another. In this partitioned configuration, side surfaces of the MMA assemblies 10 are not suitable for the placement process on the support surface 19.Further MMA assemblies 10 to be placed would represent an interference contour 32 according to Figure 3 when attempting to place further MMA assemblies 10, so that the interference contour 32 prevents the placement of further partitioned MMA assemblies 10, namely subgroups 80 thereof, because a gripping tool touching laterally, for example, collides with the previously placed MMA assemblies 10.

[0052] Gripping the MMA assemblies 10 from the rear or suctioning them with a vacuum gripper is also unsuitable, since the rear side of the MMA assemblies 10 is the joining surface, i.e., the surface that is to be brought into contact with the top side 28 of the carrier layer 18. From these considerations, it follows that, particularly for frameless MMA assemblies 10 (see Figure 2.1) in a partitioned, i.e., divided, design as a subassembly 80, neither the front side 14, which represents, for example, a mirror plane, nor the side surfaces, nor the rear side 16 (since this represents the electrical contact plane of the ASICs 20) are suitable for contacting with conventional handling devices, for example, mechanical grippers. Embodiments of the Invention

[0053] In the following description of the embodiments of the invention, identical or similar elements are designated by the same reference numerals, whereby a repeated description of these elements is omitted in individual cases. The figures only schematically illustrate the subject matter of the invention.

[0054] Figures 4 and 4.1 show a variant embodiment of a handling device 40 proposed according to the invention. This essentially comprises a frame 42 in which a mesh structure 46 is spanned. The frame 42 of the handling device 40 proposed according to the invention according to Figures 4 and 4.1 has a square geometry. Instead of the square geometry of the frame 42, it can also be rectangular or polygonal. The mesh structure 46 formed in the frame 42 forms a positioning plane 56 for the at least one M MA assembly 10 to be positioned or placed, or a subassembly 80 thereof.

[0055] The mesh structure 46 according to the top view in Figure 4.1 is formed by a first group of wires 48 and a second group of wires 50 running at right angles to the first group of wires 48. The first group of wires 48 and the second group of wires 50 can run at right angles to one another, as shown in Figure 4.1; a diagonal run or the like can also be selected. Furthermore, the frame 42 comprises alignment aids 44. The individual wires of the first group of wires 48 and the second group of wires 50 can be guided at a suitable distance from one another, preferably parallel or at right angles to one another. The alignment aids 44 can, for example, contain rotationally symmetrical parts with notches, wherein these rotationally symmetrical parts specify the exact position of the wires 48, 50 through the notches designed as recesses. The individual wires can be threaded onto one another, thereby defining their exact position.The alignment aids 44 can be fastened or clamped, for example, using screw heads indicated in the drawings. For example, these screws can act on a piece of sheet metal, which presses against the individual wires of the first group of wires 48 and the second group of wires 40 to fix them. Furthermore, index openings 52 are formed in the frame 42, diagonally opposite one another here. The index openings 52 have a diameter that is complementary to the diameter of indexing pins 62 of a joining aid 54 as shown in Figure 5. From the illustration in Figures 4 and 4.1, it can be seen that the individual wires of the first and second groups of wires 48, 50 can be adjusted with regard to their pretension using clamping devices 47.

[0056] Figure 5 shows a side view of the aforementioned joining aid 54. On its upper side, this comprises a recess pattern 60 of individual recesses 58, into which the individual wires of the first and second groups of wires 48, 50 of the mesh structure 56 engage upon interaction, i.e., upon movement of the handling device 40 and the joining aid 54 into one another. The illustration in Figure 5 shows one of the indexing pins 62, which serves to align the handling device 40 according to Figures 4 and 4.1 and the joining aid 54.

[0057] The illustration in Figure 5.1 shows a top view of the joining aid 54 according to Figure 5.

[0058] The top view according to Figure 5.1 shows that a recess pattern 60 of recesses 58, shown crossed here, runs on the top side of the joining aid 54. The recess pattern 60 is complementary to the pattern of the mesh structure 46, i.e., to the wire path of the individual wires of the first and second groups of wires 48, 50. Air outlets can be provided on the top side of the joining aid 54 in order to be able to pneumatically readjust an MMA assembly 10 that is placed on the joining aid 54. The joining aid 54 according to the illustration in Figure 5.1 comprises two indexing pins 62 that are complementary to the index openings 52 in the frame 42 of the handling device 40.

[0059] Figures 6 and 6.1 show the joining aid 54, which has been retracted into the handling device 40, 42. The pre-positioned MMA assembly 10 is arranged on the mesh structure 46 of the handling device 40 or the frame 42. In this downwardly offset state, the mesh structure 46 is therefore not yet in contact with the at least one MMA assembly 10. As can be seen from Figure 6.1, which shows an enlarged detail from Figure 6, the individual wires of the groups of wires 48, 50 of the handling device 40 run through gaps 64 of adjacently arranged ASICs 20 of the MMA assembly 10. The individual wires of the first and second groups of wires 48, 50 of the frame 42 are not yet in contact with the underside of the carrier layer 18 (MEMS die).

[0060] By subsequently lifting the handling device 40, 42, the at least one MMA assembly 10 is then lifted from the joining aid 54 or from its upper side and taken over by the mesh structure 46, which is spanned within the frame 42 of the handling device 40. The lateral position of the MMA assemblies 10 relative to one another is maintained with sufficient accuracy. In particular, the diameter of the individual wires of the first and second groups of wires 48, 50 of the mesh structure 46 is matched to the spacing, i.e., the width of the recesses 58 or the gap 64, between the ASICs 20 on the underside of the carrier layer 18 or the MEMS die.

[0061] For the sake of completeness, the illustrations according to Figures 6 to 6.2 show the alignment aids 44, which are formed laterally on the frame 42, as well as the tensioning device 47, with which the pretension of the individual wires of the groups of wires 48, 50 can be adjusted.

[0062] The illustration in Figure 6.2 shows that the MMA assembly 10 is located centrally on the spanned mesh structure 46. In the plan view according to Figure 2, the joining aid 54 is arranged below the mesh structure 46, so that when the handling device 40 is lifted, the aligned MMA assembly 10, or a subassembly 80 thereof, is taken over by the mesh structure 46.

[0063] Figures 7 to 7.2 show that an MMA assembly 10 is mounted on the mesh structure 46 (see illustration in Figure 7.2). The joining aid 54 is moved out of the handling device 40 or its frame 42, so that the MMA assembly 10, in the aligned state, rests with its underside on the mesh structure 46 or the individual wires of the first and second groups of wires 48, 50 in the positioned state. The MMA assembly 10, which is held transportably in the handling device 40, 42 according to the sequence of Figures 7 to 7.2, is now applied to a support surface 19 provided with an adhesion layer 78. The adhesion layer 78 can, for example, be a support surface 19 pre-printed with a solder paste.After passing through, for example, a reflow soldering process, the at least one aligned and pre-positioned M MA assembly 10 can be integrally connected to the support surface 19 by means of the soldering process.

[0064] This is illustrated in the sequence of Figures 8 to 8.2. The adhesion layer 78 is located, for example, on the upper side of a stamp 76, which, as shown in Figure 8, is retracted into the opening of the frame 42 of the handling device 40. When performing the reflow soldering process, for example, a material-to-material bond is formed between the carrier layer 18 (MMS die) of the MMA assembly 10, on the one hand, and the adhesion layer 78 in the form of the pre-printed solder paste, on the other. When the material-to-material bonds are formed, the individual wires of the first and second groups of wires 48, 50 are enclosed between the support surface 19, on the one hand, and the underside of the MMA assembly 10, on the other.

[0065] Figures 9 and 9.1 show that in this state, after the material-to-material connection has been established, for example by reflow soldering, between the at least one MMA assembly 10 or a sub-assembly 80 and the support surface 19, the handling device 40 has still remained in its position. The punch 76 has also remained in its position. To remove the frame 42 or the entire handling device 40, the individual wires of the first and second groups of wires 48, 50 must now be severed. This is done, for example, by severing the individual wires of the mesh structure 46 and pulling them out sideways, as indicated in Figure 9, in a withdrawal direction 82. Subsequently, as shown in Figure 9.1, the frame 42 is moved free 84 in a vertical upward direction. At the same time, the punch 76 can also be moved free 84 in a vertical downward direction.Thus, the handling device 40 or its frame 42 is free of the stamp 76, on whose adhesion layer 78 in the form of the pre-printed solder paste the at least one MMA assembly 10 is now materially connected, ie electrically connected.

[0066] Figures 10 to 10.3 show that at least one MMA assembly 10 is electrically contacted on the upper side of the exposed stamp 76. A plane 90, in which, for example, individual mirrors are located, runs above the support surface 19, which is electrically contacted with the underside of the MMA assembly 10 or with the ASICs 20 arranged on the carrier layer 18 (MEMS die) and the contacts 22 provided thereon. The upper side of the stamp 76 is shown in plan view according to Figure 10.1. This shows that, for example, individual subgroups 80 of MMA assemblies 10 lie closely together in plane 90, forming a high optical fill factor. In particular, the subgroups 80 shown in plan view in Figure 10.1 are all frameless, so that a very high optical fill factor can be achieved in this variant. Figure 10.2 shows a perspective view of the plane 90 with MMA assemblies 10 arranged thereon, which are connected in a materially bonded, ie electrically conductive, manner to the carrier surface 19 via the adhesion layer 78, formed as a pre-printed solder paste.

[0067] In the sectional view according to Figure 10.3, the electrical connection is shown again on an enlarged scale, with the carrier layer 18 located below the MMA assembly 10 on the upper side, on which ASICs 20 are arranged at a short distance from one another, the electrical contacts 22 of which are electrically connected, i.e., bonded, to the adhesion layer 78 on the upper side of the support surface 19. The further structure of the stamper 76, as indicated in Figure 10, is not shown in the illustration according to Figure 10.3.

[0068] The invention is not limited to the embodiments described here and the aspects highlighted therein. Rather, numerous modifications are possible within the scope of the claims, which are within the scope of one skilled in the art.

Claims

Claims 1. A method for placing and fastening at least one MMA assembly (10) or at least one sub-assembly (80) thereof on a carrier layer (18), comprising the following method steps: a) positioning the at least one MMA assembly (10) or the at least one sub-assembly (80) thereof on a mesh structure (46) of a handling device (40, 42), b) aligning the at least one MMA assembly (10) positioned according to method step a) or the at least one sub-assembly (80) thereof by means of a joining aid (54) that can be inserted into the handling device (40, 42), c) lifting the handling device (40, 42) and removing the at least one MMA assembly (10) or the at least one sub-assembly (80) thereof aligned according to method step b) from the joining aid (54),d) placing the at least one MMA assembly (10) or the at least one sub-assembly (80) thereof onto an upper side (28) of the carrier layer (18) provided with an adhesion layer (78) to form a material-to-material connection, and e) severing and laterally removing the mesh structure (46) from recesses (58) and / or gaps (64) beneath the at least one MMA assembly (10) or the at least one sub-assembly (80) thereof.

2. Method according to claim 1, characterized in that the at least one MMA assembly (10) or the at least one subgroup (80) thereof is inserted into an adhesion layer (78) provided as a pre-printed solder paste according to method step d).

3. Method according to claims 1 and 2, characterized in that the at least one MMA assembly (10) or the at least a subgroup (80) of this is aligned by means of the joining aid (54) before being picked up by the handling device (40, 42) without contact with the handling device (40, 42).

4. Method according to claim 3, characterized in that a lateral alignment of the at least one M MA assembly (10) or of the at least one sub-assembly (80) thereof on the joining aid (54) is carried out with pneumatic support.

5. Method according to claims 1 to 4, characterized in that according to method step b) the handling device (40, 42) and the joining aid (54) are aligned relative to each other with indexing pins (62) and openings (52) formed complementary to these.

6. Method according to claims 1 to 5, characterized in that after carrying out method step b) the handling device (40, 42) is lifted and the at least one MMA assembly (10) or the at least one sub-assembly (80) thereof is taken over by the handling device (40, 42) and the previously carried out alignment is maintained.

7. Method according to claims 1 to 6, characterized in that after method step d) a reflow soldering process is carried out, according to which the at least one MMA assembly (10) or the at least one sub-assembly (80) thereof is materially connected to an upper side (28) of the carrier layer (18).

8. Handling device (40, 42) with joining aid (54) for placing and fastening at least one MMA assembly (10) or at least a subgroup (80) thereof on an upper side (28) of a carrier layer (18) for carrying out the method according to one of claims 1 to 7, characterized in that a network structure (46) has a first group of wires (48) and a second group of wires (50) which form a positioning plane (56).

9. Handling device (40, 42) with joining aid (54) according to claim 8, characterized in that the first group of wires (48) and / or the second group of wires (50) run at right angles to one another.

10. Handling device (40, 42) with joining aid (54) according to claims 8 and 9, characterized in that the first and second groups of wires (48, 50) comprise individual wires whose cross-section (66) is smaller than a width of recesses (58) on the upper side of the joining aid (54).

11. Handling device (40, 42) with joining aid (54) according to claims 8 to 10, characterized in that it comprises clamping devices (47) for the first and second groups of wires (48, 50) and alignment aids (44).

12. Handling device (40, 42) with joining aid (54) according to claims 8 to 11, characterized in that these are made of a material suitable for clean room applications, having a low coefficient of thermal expansion in order to ensure handling accuracy, and are designed with sufficient rigidity such that deflections due to dead weight are essentially excluded.

13. MMA support surface (19) equipped with at least one MMA assembly (10) and / or at least one subgroup (80) thereof according to the method according to one of claims 1 to 7, characterized in that the MMA support surface (19) is equipped with a number of frameless MMA assemblies (10) and / or at least one subgroup (80) thereof.

14. Use of the method according to one of claims 1 to 7 for placing and fastening at least one MMA assembly (10) and / or at least one sub-assembly (80) thereof on a support surface (19) to form a material-to-material connection to the support surface (19).

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