Method for manufacturing a plurality of light-emitting components and components

Abstract

The present invention relates to a method for manufacturing a plurality of light-emitting components (1), each having at least one light-emitting semiconductor element (2), comprising the steps of arranging, fixing and wiring a plurality of semiconductor elements (2) respectively on a substrate (3), introducing a filler (8) into intermediate spaces between the semiconductor elements (2), introducing the substrate (3) together with the semiconductor element (2) fixed to the substrate (3) and the filler (8) into a cavity (12) of a mold (9), generating a negative pressure in the cavity (12) of the mold (9), introducing a matrix material (14) into the filler (8), hardening the matrix material (14), molding the substrate (3) together with the light-emitting component (1), and singulating the component (1).

Description

[Technical Field]

[0001] This application claims priority to U.S. Patent Application Publication No. 2007 / 0129994, the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present invention relates to a method for manufacturing a plurality of light emitting components each having at least one light emitting semiconductor element, to the light emitting components manufactured by this method, and to an apparatus for carrying out the method. [Background technology]

[0003] Conventional vacuum injection molding (VIM) encapsulation of semiconductor components can be performed using unfilled or partially filled materials (injection molding compounds). Unfilled materials have a high coefficient of thermal expansion (CTE). A high CTE can lead to significant substrate warpage and reliability issues, delamination, and lifting of wire contacts and chips. However, while adding fillers reduces the CTE, it also significantly increases the viscosity. Therefore, a higher fill level would not allow for complete and successful encapsulation of semiconductor components, so the highest fill level that can be achieved in practice is approximately 90% by weight. Additionally, high viscosity increases the risk of bonding wires peeling or component damage.

[0004] Until now, the problem of warpage due to high CTE has been solved by using rigid carrier systems, small substrates, and mechanical stress relief cuts or structures. To enable the use of materials with high filler contents (with adapted CTE), transfer molding has mostly been used up to now. This method requires high forces to close the mold and to fill it with the mold compound. This significantly limits the choice of substrate material and also the specific layout of the individual components and composites / panels. In addition, post-processing is usually required (e.g., a deflash step to remove undesirable mold bleed and flash, which is associated with additional mechanical stress and, in some cases, pre-damage to the panel). This method also limits the filler content and the properties of the filler itself, such as the size of the filler particles: the smaller the particles, the higher the viscosity of the mold compound when filling the mold. In optoelectronic components, small filler particles are often advantageous in terms of optical properties. The filler particles act as light guides, and larger filler particles can lead to lower contrast. In general, smaller particles are often desirable, but this should be done as much as possible without compromising the weight ratio of filler particles to matrix material, as this can have a negative impact on the CTE. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] German Patent Application Publication No. DE102021118490.8 Summary of the Invention [Problem to be solved by the invention]

[0006] One of the problems underlying the present invention is to provide a method, a component and an apparatus for implementing the method that avoids the aforementioned drawbacks. [Means for solving the problem]

[0007] The above problem is solved by a method for manufacturing a light-emitting component according to claim 1, a component according to claim 18 and an apparatus for carrying out the method according to claim 24. Preferred embodiments, improvements or developments of the proposed principle are set out in the dependent claims.

[0008] The above-mentioned object is particularly achieved by a method for manufacturing a plurality of light-emitting components, each having at least one light-emitting semiconductor element, which method comprises a step of respectively arranging, fixing, and wiring the plurality of semiconductor elements on a substrate. In a subsequent step, if necessary, the substrate can optionally be fixed to an auxiliary carrier by an adhesive layer. This is suitable when the substrate has a through-hole or a hole or is to be potted on both sides.

[0009] A filler is then introduced into the intermediate spaces between the semiconductor elements. The method further includes the step of introducing a substrate into the mold cavity with the semiconductor elements and the filler secured to the substrate. This step may be replaced by the step of introducing the filler.

[0010] Next, a negative pressure is generated in the mold cavity, and the matrix material is introduced into the filler. The negative pressure causes the thin liquid matrix material to completely disperse into the cavity between the filler and the matrix material. The matrix material is cured, and the auxiliary carrier is molded with the light-emitting component. Subsequently, in some embodiments, the component can be singulated.

[0011] According to the proposed principle, the filler and matrix material are introduced into the mold in two separate steps. This allows for very high filler contents, fewer restrictions on the selection of filler particle size, and significantly reduced clamping forces and filling pressures. In particular, with an appropriate filler size distribution, filling degrees in the range of 80% to 98%, especially greater than 80% or greater than 85%, and in the range of 85% to 93%, can be achieved. Furthermore, as will be explained in more detail later, delamination of the matrix material at the substrate and / or component boundaries can be reduced. Just as with the use of different fillers, a better, locally tailored filling degree distribution is possible. Separate steps allow for greater flexibility in adapting to the specific needs of the semiconductor body and the interconnects.

[0012] The filler is particularly flowable and, in some embodiments, can comprise at least one material selected from spherical SiO2 particles, TiO2, AlN, Al2O3, and BN. The term "flowable" should be understood to mean that the particles do not adhere to one another and, in some embodiments, are smooth, round, or rounded. Combinations can also be used if necessary to match the CTE of the surrounding material overall. Coated particles are also advantageous for optimizing optical and mechanical properties. In one embodiment of the present invention, the filler contains particles of various sizes, or alternatively particles of substantially the same size. In this case, a size distribution can be selected that is well suited to the cavity to be filled. Additionally, in some embodiments, it is contemplated to adapt the particle size distribution to the desired degree of filling. For example, smaller particle sizes can be used for higher degrees of filling. In one development of the present invention, nanoparticles (TiO2, carbon black) are used in the matrix material and / or filler.

[0013] In some embodiments, the matrix material contains silicone and / or epoxy resin, according to the proposed principles.

[0014] In some embodiments of the proposed principle, the semiconductor component is fixed in method step b) by a release foil (e.g., ETFE, PET), which protects the light-emitting surface in particular from contamination. In the molding equipment itself, this foil is provided as an endless roll and is transported further after each molding. Other foils can also be used. Alternatively, the light-emitting surface can be covered with photoresist or the like, thus avoiding contamination or damage. After the molding process, this photoresist can be removed again. In other embodiments, the applied particles can also be used precisely to roughen the surface of the light-emitting component. This can be done, for example, by brushing, as described below, or by doctor blade application.

[0015] In one embodiment according to the proposed principle, in method step c) regions of the light emitting semiconductor component are masked.

[0016] In some embodiments of the proposed principle, in method step c), the filler is doctor bladed and / or brushed through a sieve structure. Alternatively, the filler is shaken off and / or sprinkled and / or poured. In some embodiments, the filler can also be dispensed. Then, in some embodiments of the proposed principle, excess filler can be removed after method step c).

[0017] Some embodiments address particle packing. As mentioned above, the particles can be approximately the same size (or have a fairly narrow size distribution), but can also have relatively large and wide size distributions. The size distribution can depend on the structure of the space to be filled and the desired degree of packing. Regardless of the specific process, mixtures with the respective distributions can be processed during packing. This ensures that the size distribution of the filled space remains approximately the same even in the packed state. However, in some embodiments, particles of different sizes can be packed one after the other. This allows for the formation of layers, with distinct interfaces, but also wider transitions, between the individual layers, achieved through several steps, as will be explained further below. In this case, such stacking can result in both vertical and horizontal interfaces. Correspondingly, such parts exhibit interfaces with large gradients or abrupt rises in filler size or filler material.

[0018] In some embodiments, it is contemplated to use a different filler material on the side of the substrate opposite the semiconductor components, or a different filler level than the side of the substrate bearing the components. The size distribution of the filler material may vary.

[0019] In some embodiments of the proposed principles, different distributions are used to compensate for differences in the coefficients of expansion that may occur in the materials used. For example, a different size distribution or a different degree of fill may be used in some regions of the substrate than in the semiconductor body or in regions around the interconnects of the semiconductor body. Similarly, different materials may be used as fillers. The components thus formed are therefore characterized by gradients in fill, material, or other parameters.

[0020] After method step c), the filler can be densified and / or dispersed by shaking. It should be noted that such shaking also results in a change in size distribution depending on the intensity and duration. Generally, after a longer shaking period, larger particles "float" to the top, while smaller particles sink to the bottom. This process can be precisely utilized, for example, by using a non-uniform particle size distribution during filling, to compensate for this non-uniform particle size distribution again in a subsequent shaking process. In some embodiments of the proposed principle, shaking can also be used to release the light-emitting surface of the component. Steps b) and c) can be repeated several times to ensure uniform filling. This may be necessary, for example, if only a partial amount of filler is filled and then uniformly dispersed in the intermediate space by shaking.

[0021] In step d) of introducing the filler into the cavity, the upper side, i.e., the side with the semiconductor component, can be covered with an elastic punch or cover. This primarily prevents the filler from spilling out. The punch or cover should be elastic and made of a plastic, such as PDMS. This plastic has the advantage that it is transparent, allowing the resin packed into it to be cured with light. The negative pressure generated later creates a tight seal, especially on the upper side of the component, which the matrix material cannot reach, so only a limited amount of pressing or pressure is required. After covering, the structure can be shaken again or rotated to achieve a uniform filler distribution.

[0022] Another aspect of the proposed principle further relates to the step of introducing the matrix material and the step of creating a negative pressure prior to or associated therewith.

[0023] A large, rapid pressure gradient can lead to undesirable particle redistribution, and in the worst case, the filler may move from its position and block the gas outlet. Therefore, in some embodiments, it may be advantageous to generate the necessary negative pressure at a moderate speed rather than suddenly. In this case, the speed may depend on the mold geometry, the circumference of the gas outlet, the shape and type of part present in the mold, and even the particle size or distribution. In some embodiments, a special gas-permeable membrane or sieve can be provided, which is placed at or before the gas outlet, thereby preventing the migration of filler to the gas outlet and the negative pressure line. This membrane or sieve can remain in the part in its completed state.

[0024] The negative pressure can be controlled by a valve or similar device. In some embodiments, the negative pressure is generated during the generation of the negative pressure while the matrix material is being introduced. Thus, in these embodiments, the matrix material is sucked into the interspace of the filler by pumping out the gas. In some other embodiments of the proposed principle, the negative pressure is at least partially generated before the matrix material is introduced. In this way, the flow of the matrix material can be better controlled. In some embodiments, it is expedient to first remove a large amount of gas, for example, until the pressure is less than 10 mbar, particularly less than 1 mbar. Typically, the pressure can be from 0.1 mbar to 50 mbar. This ensures that gas pockets in inaccessible locations do not form.

[0025] In this regard, it is also possible to maintain a negative pressure during the introduction of the matrix material, for example by continuously pumping it out. In all these embodiments, the amount of matrix material can also be controlled by a valve or other measures, for example by the shape of the inlet. Since the negative pressure can be at most the respective air pressure, i.e., about 1000 mbar, a greater pressure difference is not possible, thereby reducing the risk of damage to the wires or semiconductor components when applying a matrix material with a low viscosity. Compared to pressurization under high pressure, this is an important advantage of the principle proposed here.

[0026] In some embodiments of the proposed principle, pressure can be applied to the matrix material at the inlet, thereby pumping additional matrix material into the intermediate space. In some embodiments, this can be achieved by hydrostatic pressure, with the reservoir containing the inlet supply located higher than the area to be filled. The hydrostatic pressure can be adjusted by adjusting the height or controlling the amount of material or a controllable pressure relief valve. In some embodiments, it is contemplated to use hydrostatic pressure as an auxiliary to the introduction process by negative pressure. In some embodiments, hydrostatic pressure can also be achieved by controlled and delicate pressure application, thereby opening up additional degrees of freedom in the process implementation. In some embodiments, the hydrostatic pressure is controlled in time. Thus, for example, the hydrostatic pressure can be increased only several hours after the first introduction or supply, especially if the possibly existing partial negative pressure is no longer sufficient to continue introducing the matrix material.

[0027] In one embodiment of the present invention, the mold includes an inlet for introducing the matrix material and an outlet for creating a negative pressure, the inlet passing through the auxiliary carrier and, if necessary, through a region of the substrate.

[0028] By covering the substrate or the entire assembly, and before or after generating the negative pressure, the substrate or the entire assembly can be rotated, so that the space filled with the filler or matrix material extends substantially vertically. In this case, the material inlet and the gas outlet can be located at the top or bottom depending on the application. Therefore, in some embodiments, it may be useful to provide the gas outlet at the lowest point, thereby acting to assist gravity and capillary forces. It should be noted here that in such cases, the filler must fill the existing hollow space as completely as possible to prevent the filler from falling "down" due to rotation and showing a low filling degree at the top. However, this effect can also be utilized if it is deemed appropriate to create the desired filling degree.

[0029] Thus, in some embodiments, in method step f), the mold is positioned at an angle of approximately 90° to the horizontal. In one embodiment of the present invention, the mold comprises a means for preventing the matrix material from flowing out of the outlet, which is a filter strip or block, particularly made of plastic or ceramic, arranged in the area of ​​the outlet, thereby preventing the matrix material from blocking the outlet. In this case, this means can be arranged in addition to or instead of the above-mentioned membrane or sieve.

[0030] In one embodiment of the present invention, the auxiliary carrier and the adhesive layer have passages, and the negative pressure is generated in the filler by a plurality of gas outlets in the mold corresponding to the passages, in which case it can be envisaged that the substrate is positioned substantially horizontally and the matrix material enters through the passages, disperses there, and partially exits again via the corresponding gas outlets, where it is received in the reservoir.

[0031] In some embodiments of the proposed principle, the mold includes multiple inlets through which the matrix material is introduced into the filler. Additionally, multiple outlets can be provided. In some embodiments, it is expedient to displace the inlets and outlets for the matrix material from one another. In some embodiments, the number of inlets can be different from, and in particular greater than, the number of outlets. It is also possible to configure the inlets to be larger in circumference than the outlets. In this way, better distribution can be achieved.

[0032] Some other aspects relate to a light-emitting component. In some aspects of the proposed principle, the light-emitting component includes at least one light-emitting semiconductor element disposed on a substrate, the light-emitting semiconductor element being at least partially surrounded by a filler embedded in a matrix material. For simplicity, the combination of the filler and the matrix material is also referred to as a mold. The filler is particularly flowable and, in one embodiment of the present invention, contains at least one substance selected from spherical SiO2 particles, TiO2, AlN, and BN. In this case, the filling degree of the mold is greater than 92%, particularly greater than 95%, for example, between 95% and 98%.

[0033] In some embodiments of the proposed principle, the filler introduced comprises a particle size distribution, which allows the degree of filling to be adjusted over a wide range, in particular when the degree of filling is relatively high, i.e., above 95%, the number of smaller particles will be greater than the larger particles.

[0034] In some other embodiments, the filler has a substantially uniform particle size. In various embodiments, the particles can be embedded in a matrix material, particularly a silicone and / or epoxy resin. In some embodiments, based on the advantageous methods proposed herein, the filler exhibits a packing gradient, or even a particle size gradient. Thus, the mold of the part can have a packing gradient that increases in one direction, with higher packing degrees being characterized by smaller average particle sizes. In some other embodiments, the mold can include an interface with the filler, i.e., the mold can be subdivided into a first region having a first packing degree, and therefore a first CTE, and at least one second region having a second packing degree and a second CTE.

[0035] In yet another aspect, the part includes a membrane or sieve, or a portion of a membrane or sieve, embedded in the mold. These can be located, inter alia, on one side of the substrate, with the opening covered by the substrate carrier. In some embodiments, such membrane or sieve residue can also be present on the cut or singulated edges of the part. The proposed method using vacuum injection molding provides parts that largely avoid trapped gas pockets or areas of low mold density. Correspondingly, in some embodiments, the part can have a consistent mold that is substantially free of gas pockets and has no voids.

[0036] The problem stated at the beginning is also solved by an apparatus for carrying out the method according to the invention, which comprises a mold having an upper mold plate and a lower mold plate which surround a cavity and which are separable from each other, the mold having at least one inlet opening through which the matrix material can be introduced and at least one outlet opening through which the cavity can be evacuated.

[0037] In the above-disclosed embodiments of the proposed principle, the characteristics of light-emitting or optoelectronic semiconductor components are utilized. However, it should be emphasized here that the invention is not limited to the use of such specific components. Rather, the proposed method is capable of and is intended to encapsulate semiconductor components, components or chips in general.

[0038] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. [Brief explanation of the drawings]

[0039] [Figure 1] FIG. 1 is a first schematic diagram of an example embodiment to clarify some aspects of the proposed principles. [Figure 2] FIG. 2 is a second schematic diagram of an example embodiment to clarify some aspects of the proposed principles. [Figure 3] 1A-1C show examples of filler application according to some aspects of the proposed principles. [Figure 4] Schematic representation of possible structures of fillers that can be used in the proposed method. [Figure 5] FIG. 10 is another schematic illustration of the introduction of filler after removal of the stencil (Schablone) for the purpose of clarifying some aspects. [Figure 6] 1 is a diagram of an example of a filler introduced into an intermediate space of a support substrate on which a semiconductor component is mounted. [Figure 7] 1A-1C show examples of the creation of negative pressure in a mold cavity and the introduction of matrix material into a filler according to some aspects of the proposed principles. [Figure 8] FIG. 10 is another schematic diagram of an alternative embodiment of creating a negative pressure in the cavity of the mold and introducing matrix material into the filler. [Figure 9] 1 is another example of the implementation of some method steps to illustrate various aspects of the proposed method. [Figure 10]1 is another example of the implementation of some method steps to illustrate various aspects of the proposed method. [Figure 11] 1 is another example of the implementation of some method steps. [Figure 12] 1 is another example of the implementation of some method steps. DETAILED DESCRIPTION OF THE INVENTION

[0040] FIG. 1 shows several light-emitting components 1, each containing a light-emitting semiconductor element 2 in the form of a light-emitting diode or laser diode. In a first method step a), the semiconductor elements 2 are placed on a substrate 3, here a QFN lead frame, and a converter 4 is attached and electrically connected to the wire contacts 5. In the next method step b), the semiconductor elements are mounted on an auxiliary carrier 6 according to the shape and form of the substrate and temporarily fixed thereon, for example, by an adhesive layer 7, e.g., by an adhesive foil or laminate foil. The foil 7 can have temperature-dependent adhesion, allowing the completed component to be easily removed again by heating. The placement using the auxiliary carrier 6 ensures sufficient stability. Additionally, as shown in the cross-sectional view, the pre-mounted substrate 3 (ceramic, PCB, lead frame, etc.) can have openings or through-holes. Thus, the auxiliary carrier on which the underside of the substrate rests creates a cavity that can be filled in a subsequent method step. In this way, the substrate is also surrounded by a mold, thereby protecting it from multiple sides.

[0041] In the next process step c), a flowable filler 8 is applied to the substrate 3. The filler may comprise glass or SiO2 particles, which are initially round but may have other shapes depending on the application and production. Other fillers, such as TiO2, AlN, or BN, are also suitable. If the filler should have additional properties, such as color or conductivity, the filler can be selected appropriately or additional particles with these properties can be added. In this case, the additional particles may have similar CTE properties or must be taken into account when determining the CTE.

[0042] In this embodiment, all intermediate spaces between the semiconductor element 2 and the substrate 3 are completely filled. Depending on the application, the filler may consist of particles of various sizes to achieve a dense sphere packing, or alternatively, particles of the same size to achieve a very homogeneous layer, thereby preventing particle segregation. By using an appropriate size distribution, the degree of filling can also be adjusted without leaving relatively large intermediate spaces between the semiconductor components.

[0043] In the subsequent method step d), as shown in FIG. 2 , the auxiliary carrier 6, together with the semiconductor element 2 and the filler 8 disposed thereon, is placed in the cavity 12 between the two mold plates 10, 11 of the mold 9, where the semiconductor element 2 is fixed and covered by an elastomer, for example, in the form of PDMS 13, thereby protecting the surface of the converter 4, for example. Unlike transfer molding, VIM is performed at significantly lower pressures, so the use of an elastomer is both practical and sufficient. Furthermore, the use of PDMS is advantageous because it is transparent to light, especially UV light, which allows the exposure and curing of the matrix material, as described further below, to occur without the need to remove the cover. The adjustment plate 28 allows the auxiliary carrier 6 to be positioned and fixed as desired within the mold 6.

[0044] In the next method step e), a negative pressure is created in the mold cavity 12, which for clarity is not shown in the drawings, and then in method step f), a liquid matrix material 14, for example a silicone, an epoxide, etc., is added to the particle bed of the pre-packed filler 8. As will be explained below, the matrix material can be introduced in various ways. The matrix material is a thin liquid, i.e., has only a low viscosity, so that it can penetrate into any interstitial spaces still remaining in the filler and fill them.

[0045] In method step g), hardening of the matrix material 14 takes place, then in method step h), shaping of the auxiliary carrier 6 together with the light-emitting component 1 takes place, and in method step i), singulation of the component 1 takes place. Further processing steps can take place between the aforementioned method steps.

[0046] 3 shows a schematic diagram of the application of filler in method step c). First, in method step c1), a stencil 15 or a sheath is placed on the mounted side of the auxiliary carrier 6, thereby covering the light exit surface of the converter 4. An elastomer 29, for example an adhesive foil, can be attached to the sheath on the side facing the semiconductor component 2.

[0047] Then, in step c2), filler 8 is applied and, in method step c3), it is distributed by means of a brush 16 or a doctor blade or the like, by moving it over the stencil 15 in the feed direction V. For this purpose, the stencil 15 has openings 17 through which the filler can flow into the intermediate spaces between the semiconductor elements 2.

[0048] FIG. 4 shows a schematic diagram of the structure of the filler after it has been introduced into the interspace between the semiconductor elements 2. The filler can have particles P as spheres, hollow spheres, etc. The size distribution of the particles P can adjust the degree of filling. Therefore, the process shown in FIG. 3 can also be repeated with fillers of different sizes, potentially resulting in a gradient in the degree of filling or particle size distribution. This gradient can be both vertical and horizontal, for example, when different fillers are spatially arranged in different areas that are subsequently doctor-bladed or removed.

[0049] Alternatively, the particles can have substantially the same size. As an alternative to this variant shown in Figure 3, the filler can also be dispensed after (or even without) the stencil. A simple pour-in is also conceivable, especially if no light-emitting components are used, thereby eliminating the risk of damaging the light-emitting surface. Naturally, the stencil can also be combined with other measures for packing the filler into the intermediate spaces.

[0050] 5, the stencil 15 is now removed, and the filler 8 is now unevenly distributed between the semiconductor elements 2, and the intermediate spaces are not completely filled. The illustrated ridges therefore protrude slightly beyond the light-emitting surface and the converter bodies 4. Nevertheless, in this embodiment the overall amount of plastic introduced in this way is selected so that it fills the remaining cavities and at the same time provides the desired degree of filling across the size distribution used.

[0051] Next, as shown in FIG. 6, the auxiliary carrier is shaken, so that the filler 8, which is flowable per se, is uniformly distributed in the intermediate spaces between the semiconductor elements 2.

[0052] FIG. 7 shows a schematic diagram of process step e) of generating a negative pressure in the cavity 12 of the mold 9 and process step f) of introducing the matrix material 14 into the filler 8. The mold 9 is arranged vertically, so that gravity acts parallel to the auxiliary carrier 6. The mold 9 includes a lower inlet 18 for introducing the matrix material 14 and an upper outlet 19 for generating a negative pressure. The outlet is pneumatically connected to a compressor 20, which may be an optionally configured suction pump. To protect the compressor 20 from the surging matrix material 14, an overflow 21 is arranged downstream of the compressor 20, which, as shown in the schematic diagram, is a vertically arranged tube or collection container. The lower inlet 18 is connected to a filling pipe 22, which is connected to a reservoir 23, the filling height of which is higher than the outlet 19 by a distance h. Thereby, hydrostatic pressure is generated when the matrix material 14 fills and embeds into the cavity of the mold 9 filled with the filler 8, the minimum value of which at the outlet 19 is determined by the height h.

[0053] The dense packing of the filler 8 makes filling difficult. For this reason, several forces are used in parallel to introduce the matrix material. First, negative pressure or vacuum force is generated by a pump 20. Capillary forces between the filler particles are also added. The hydrostatic force is adjusted by a height difference h, where an additional valve (not shown) can be used to adjust the pressure. In this way, it is possible to prevent the filler from being displaced again by a sudden pressure increase or by the inflowing matrix material. Optionally, additional pressure can be applied to the liquid matrix material 14 to assist the filling process.

[0054] FIG. 8 shows a schematic diagram of an alternative embodiment of method step e) of generating a negative pressure in the cavity 12 of the mold 9 and method step f) of introducing the matrix material 14 into the filler 8. Here, the mold 9 is positioned horizontally, with the inlet 18 and outlet 19 now located at the same height. Additionally, the mold with the introduced substrate and filler is rotated. This action has the advantage that the filler falls again toward the converter material and the PDMS punch 13. That is, the filler collects on the PDMS punch. If the distribution in the punch is not uniform, the density will be lower, especially in the substrate region, which will result in more matrix material being deposited there later in the process. In this case, a substrate structure suitable for withstanding these forces can be formed without causing delamination, even though the CTE will be locally increased there.

[0055] Again, a positive or negative pressure can be applied to the reservoir 23 to assist the vacuum. A filter element 24, such as a membrane, filter paper, fine sieve, plastic gauze, or ceramic frit, is placed in front of the outlet 19 in the mold 9 and attached as a strip or block to the auxiliary carrier 6. This filter element prevents the generated vacuum from moving filler particles toward the pump. On the other hand, if the matrix material reaches the outlet, it prevents the particles from being transported by the matrix material. Thus, the filler remains entirely in the intermediate space. In some embodiments, the element 24 is liquid-tight but gas-permeable, thereby reducing or preventing overflow or inflow into the outlet. This allows the outlet in the PDMS punch 13 (see FIG. 2) to remain clean and can be used multiple times without extensive cleaning.

[0056] 9 and 10 show another embodiment of method steps c) to f). Fig. 9 shows a cross-sectional view of the loaded auxiliary carrier after introducing filler 8 and dispersing the filler by rocking. Fig. 10 shows a schematic view of the loaded auxiliary carrier 6 and with filler 8 attached, positioned in a mold 9, when the filler charge is evacuated. Passages 25 are arranged in the auxiliary carrier 6 and adhesive layer 7 between some or all of the substrates 3 or in the areas of voids in the substrates 3. The passages 25 are covered with air-permeable filters or sieves 26, so that the passages are located between elements of the substrates 3 as shown.

[0057] The filter 26 is impermeable to the liquid matrix material 14 and the flowable filler 8. These passages 25 allow for easier and more rapid evacuation of the area packed with the filler material 8. In addition, one of the plates 10 of the mold 9 has a plurality of outlet openings 19 distributed across its surface and connected to pneumatic lines (not shown) and the suction side of one or more compressors. Correspondingly, the other plate 11 has a plurality of inlets 18 for introducing the matrix material 14.

[0058] The number of inlets in the mold plate 11 is smaller than the number of outlet openings 19, and the passages 25 are also significantly smaller in size. However, this also results in a uniform negative pressure and suction action, which allows the matrix material to reach even small areas and intermediate spaces of the substrate 3 and adhesive foil, especially near these passages 25. The membrane becomes part of the part after the matrix material hardens, so that this can even be directly confirmed by the membrane after singulation. In this embodiment, the filter elements 26 are singulated and positioned only above the passages. However, it may also be possible to provide a consistent foil, or the membrane is part of the adhesive foil 7.

[0059] 11 and 12 show another alternative embodiment of method steps c) to f). The auxiliary carrier 6 here corresponds to the auxiliary carrier 1 described with reference to FIG. 1, i.e. does not have the passages 25. The upper mold plate 11, as in the previous embodiment, has a number of inlets 18 for introducing the matrix material 14. In contrast to the previous embodiment, the mold is evacuated laterally, as indicated by the horizontally arranged arrow 27.

[0060] Additionally, this example demonstrates the particle size gradient created by the various filling processes with different size particles of filler introduced and subsequent rocking motion. [Explanation of symbols]

[0061] 1 Light-emitting component 2. Light-emitting semiconductor elements 3. Circuit Board 4 Transformation 5 wire contacts 6 Auxiliary Carrier 7 Adhesive layer 8. Filler 9. Mold 10 Lower mold plate 11 Upper template 12 Cavity between the lower mold plate and the upper mold plate 13 adhesive foil 14 Matrix Materials 15 Stencils 16 Brushes 17 Stencil opening 18 Entrance 19 Exit 20 Compressor 21 Overflow 22 Filling tube 23 Reservoir container 24 filter elements 25 Passage 26 filters 27 Arrow 28 Adjustment plate 29 Elastomer V Feed direction

Claims

1. A method for manufacturing a plurality of light emitting components (1), each having at least one light emitting semiconductor element (2), comprising: a) placing, fixing and wiring a plurality of semiconductor elements (2) on a substrate (3); b) fixing said substrate (3) to an auxiliary carrier (6) by means of an adhesive layer (7); c) introducing filler (8) into the intermediate spaces between the semiconductor elements (2); d) introducing the substrate (3) together with the semiconductor element (2) fixed to the substrate (3) and the filler (8) into the cavity (12) of the mold (9); e) creating a negative pressure in the cavity (12) of the mold (9); f) introducing a matrix material (14) into said filler (8); g) curing said matrix material (14); h) molding said substrate (3) together with said light emitting component (1); i) singulating the light emitting components (1); A method comprising:

2. 2. The method according to claim 1, wherein the filler (8) is flowable and / or the filler and matrix material are introduced one after the other.

3. 3. The method according to claim 1 or 2, wherein the step of introducing the filler is carried out by introducing a suspension comprising a volatile solvent and the filler, and the volatile solvent is evaporated until the intended amount of filler is introduced.

4. 2. The method of claim 1, wherein the filler (8) contains at least one material selected from spherical SiO2 particles, TiO2, AlN, Al2O3, BN.

5. 2. The method of claim 1, wherein the filler (8) has a predetermined size distribution, and the desired degree of filling depends on the predetermined size distribution.

6. 2. The method according to claim 1, wherein the introduction of filler (8) into the intermediate space is carried out several times using fillers with different size distributions.

7. The method of claim 1 , wherein the matrix material (14) comprises a silicone and / or an epoxy resin.

8. 2. The method according to claim 1, wherein in method step d) the semiconductor element (2) is covered by an elastic punch.

9. 2. The method according to claim 1, wherein, before method step c), regions of the semiconductor component (2) are masked.

10. 2. The method according to claim 1, wherein in method step c) the filler (8) is doctor bladed and / or brushed and / or shaken off and / or sprinkled and / or poured through a sieve structure (15).

11. 11. The method according to claim 10, wherein after method step c) excess filler (8) is removed.

12. 12. The method according to claim 10 or 11, wherein after method step c) the filler (8) is densified and / or dispersed by rocking.

13. The method of claim 12 , wherein the step of introducing the filler and / or the step of agitating are repeated.

14. In method step f), the mold (9) is positioned at an angle of approximately 90° to the horizontal, or 2. The method according to claim 1, wherein in method step f) the mould (9) is rotated by 180°.

15. 2. The method of claim 1, wherein the mold (9) comprises an inlet (18) for introducing the matrix material (14) and an outlet (19) for creating the negative pressure.

16. The method described in claim 15, wherein the inlet (18) and the outlet (19) are located on the same side of the mold.

17. 16. The method of claim 15, wherein the mold (9) comprises means (24) for preventing the matrix material (14) from flowing out of the outlet (19).

18. 18. Method according to claim 17, characterized in that the means (24) are filter strips or blocks made of plastic or ceramic, arranged in the region of the outlet (19).

19. 2. The method according to claim 1, wherein the auxiliary carrier (6) and the adhesive layer (7) have passages (25), and a negative pressure is generated in the filler (8) by a plurality of outlets (19) in the mold (9) corresponding to the passages (25).

20. 20. The method of claim 19, wherein a plurality of filter elements are provided, each of the plurality of filter elements being positioned above the passage (25).

21. The method described in claim 20, wherein the plurality of filter elements become part of the light-emitting component after the matrix material hardens.

22. 2. The method of claim 1, wherein the mold (9) includes a plurality of inlets (18) through which matrix material (14) is introduced into the filler.

23. 23. The method of claim 22, wherein the number of inlets is different from the number of outlets.

24. A light-emitting component (1) having at least one light-emitting semiconductor element (2) arranged on a substrate (3), the light-emitting semiconductor element (2) being at least locally surrounded by a filler (8) embedded in a matrix material (14), the degree of filling of the filler in the matrix material being greater than 70% by weight, and the filler (8) in the matrix material having particles with a particle size gradient extending in one direction along the light-emitting component.

25. 25. Light emitting component according to claim 24, wherein the filler (8) is flowable.

26. 26. A light emitting component according to claim 24 or 25, wherein the filler (8) contains at least one substance selected from the group consisting of spherical SiO2 particles, TiO2, AlN, Al2O3, BN.

27. 25. A light emitting component according to claim 24, wherein the filler (8) comprises a size distribution and the degree of filling depends substantially on the size distribution.

28. 25. The light emitting component according to claim 24, wherein the matrix material (14) contains silicone and / or epoxy resin.

29. 10. An apparatus for carrying out the method according to claim 1, comprising a mold (9) having an upper mold plate (11) and a lower mold plate (10) which surround a cavity (12) and which are separable from each other, said mold (9) having at least one inlet opening (18) through which a matrix material (14) can be introduced and at least one outlet opening (19) through which said cavity (12) can be evacuated.

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