METHOD AND FORMING TOOL FOR EMBEDDING OPTOELECTRONIC COMPONENTS IN A LAYER

Abstract

A method for embedding optoelectronic components in a layer, wherein the components are arranged side by side at intervals on a support, wherein a molding tool with a support plate is provided, the support plate having resilient support areas on a bottom side, wherein the support plate with the resilient support areas is placed on the top sides of the components, wherein a space between the components, the support, and the support plate is filled with a molding material, the molding material being cured to form the layer, and wherein the molding tool is removed from the layer and the embedded components, wherein the molding tool has a pressure plate, the pressure plate having support elements on a bottom side, the support elements being spaced apart from one another, and wherein the pressure plate with the support elements rests on a top side of the support plate.the pressure plate with the support elements presses the support plate against the components when the molding material is poured into the space.

Description

[0001] The invention relates to a method for embedding optoelectronic components in a layer and a mold for carrying out the method.

[0002] It is known from the prior art to embed optoelectronic components in a layer using an injection molding process or a foil-assisted molding process. However, this can result in damage to the components or overmolding of the upper surface of the components.

[0003] DE 10 2011 078 906 A1 discloses a method for producing an optoelectronic semiconductor component by means of transfer molding, wherein a molding tool is provided which has a carrier onto which the semiconductor components are placed. The semiconductor components have radiation conversion elements on their upper surfaces. A tool part in the form of a cap is applied over the semiconductor components, which cap rests on the upper surfaces of the radiation conversion elements of the semiconductor components. In one embodiment, the support plate can have projections that rest on the radiation conversion elements of the semiconductor components. After the support plate has been placed on the radiation conversion elements of the semiconductor components, the space between the components is filled with molding material. In one embodiment, a photoresist or a film can be arranged between the support plate and the radiation conversion elements.

[0004] The object of the invention is to provide an improved method for embedding optoelectronic components in a layer. Furthermore, the object of the invention is to provide an improved mold for embedding optoelectronic components in a layer.

[0005] The objects of the invention are solved by the independent patent claims.

[0006] An advantage of the proposed method is that the contact pressure on the components is reduced, while still reliably protecting the upper side of the components from the application of molding material. This is achieved by providing a molding tool with a support plate, the support plate having resilient support areas on its underside. The resilient support areas of the support plate are placed on the upper sides of the components. The components are arranged on a carrier. A space between the components, the carrier, and the support plate is then filled with molding material. The molding material is cured to form the layer. The molding tool is then removed. The layer with the components can, for example, be separated into individual components.The optoelectronic components can be designed, for example, in the form of light-emitting components, particularly light-emitting diodes. The resilient support areas of the support plate allow components of different heights or components with inclined upper surfaces to be more reliably covered and protected from mold material. This allows the mold to be placed on the components with less pressure. This reduces the risk of component damage.

[0007] The mold has a pressure plate, wherein the pressure plate has support elements on an underside. The support elements are spaced apart from one another. For example, the support elements are arranged in a second grid. The pressure plate rests with the support elements on an upper side of the support plate. When the mold material is poured into the intermediate space, the pressure plate is pressed against the upper side of the support plate by the support elements. The support elements are arranged at least partially laterally next to the components. In this way, the pressure plate can exert high pressure on the support plate with the help of the support elements. The support elements allow the pressure to be transferred to the support plate in areas between the components. This can reduce the direct pressure on the components. This reduces the risk of damage to the components.

[0008] In one embodiment, the support plate is made of a resilient material. Thus, the underside of the support plate provides the resilient support areas. For example, the support elements of the pressure plate can be arranged at least partially laterally next to the components. For example, all support areas are arranged laterally next to the components. Thus, the pressure can be transferred between the pressure plate and the support plate between the components. Due to the resilient design of the support plate, the pressure can be transferred more evenly to the components. For example, the support plate can bend in the area between the components. This allows height differences between the components and inclined top sides of the components to be compensated for with minimal stress on the individual components.

[0009] In one embodiment, the support plate has support blocks on its underside. The support blocks protrude from a base plate of the support plate at the bottom. The support blocks are arranged in the same grid as the components. The support blocks have support surfaces, wherein the support surfaces are provided for resting on the components. The support blocks have, for example, an approximately identical shape and / or an approximately identical size to the upper sides of the components. However, it is advantageous if the support blocks at least completely cover the upper sides of the components. In this way, covering the components with molding material can be avoided. By providing the support blocks, the support pressure from the support plate can be transferred directly to the upper sides of the components.In particular, when the base plate and / or the support blocks are made of a resilient material, a good distribution of the support pressure on the individual components can be achieved in this way without damaging the components.

[0010] In one embodiment, the support blocks are resiliently connected to the base plate of the support plate. This embodiment allows for a certain degree of mobility of the support blocks, even with a rigid base plate. If the support plate itself is made of a resilient material, the resilient connection of the support blocks to the support plate can further increase the flexibility of the support blocks. This allows for better adjustment of the height position of the support blocks and / or their inclination relative to the components.

[0011] In one embodiment, the support blocks can be connected to the support plate via spring elements. The spring elements can be designed, for example, in the form of leaf springs or disc springs. The spring elements can be connected to the support blocks and the support plate via adhesive or welding.

[0012] In one embodiment, molding material is poured into the gap as a molding material. A silicone-glass composite, for example, can be used as the molding material. Using the molding material, a molding process can be used to produce the layer.

[0013] In one embodiment, a film is arranged between the mold and the components, or between the mold and the intermediate space. The film protects the mold from wetting with molding material. Furthermore, the film is made of an elastic material and thus represents an elastic component between the mold and the components. For example, the film can have a thickness of 40 µm.

[0014] To carry out the method, a molding tool is proposed which, in a simple embodiment, comprises a support plate, wherein the support plate has resilient support areas. The resilient support areas are provided for being placed on components. The components can be arranged on a carrier. The support plate is also designed to define a gap between the support plate, the components, and the carrier for filling molding material. By providing the resilient support areas, different height positions of the components or different inclinations of the upper sides of the components can be covered with less pressure and with greater reliability. Thus, the application of molding material to the upper sides of the components can be reliably avoided.

[0015] The mold has a pressure plate, with the pressure plate having support elements on its underside. The support elements are spaced apart from one another. The pressure plate rests with the support elements on an upper side of the support plate. The support elements transfer the pressure to the support plate. The support elements can compensate for any unevenness of the support plate for even pressure distribution. The underside of the support plate has resilient support areas. The support areas are intended to be placed on the components. Furthermore, the support plate can be designed to bend in areas between the components.

[0016] In one embodiment, the support plate has support blocks on its underside. The support blocks are arranged at a distance from one another. The support blocks have support surfaces for resting on the components.

[0017] In one embodiment, the support blocks are spring-mounted to the support plate. This increases the flexibility of the support blocks. Thus, larger unevenness or larger height differences between the top surfaces of the components can be compensated for with fewer pressure peaks for the individual components.

[0018] In a further embodiment, the support plate is made of a resilient material, in particular spring steel. The resilient design of the support plate improves pressure equalization when applied to components of different heights and / or to surfaces of the components with different inclinations.

[0019] Depending on the selected embodiment, the molding tool can have a film arranged between the molding tool and the components or between the molding tool and the intermediate space. This protects the molding tool from wetting with molding material. Furthermore, the film can be made of an elastic material, which further increases the resilient properties of the molding tool.

[0020] The above-described properties, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more readily understood in connection with the following description of the embodiments, which are explained in more detail in connection with the drawings. Fig. 1 a schematic cross-section through a device for embedding components in a layer, Fig. 2 a schematic partial view of a pressure plate of the mold, Fig. 3 a schematic plan view of an underside of a support plate, Fig. 4 a schematic representation of the arrangement of the components and the support elements of the printing plate of the Fig. 1, Fig. 5 a schematic cross-section through a further embodiment of a device for embedding the components in a layer, Fig. 6 a schematic partial view of an underside of the support plate of the Fig. 5, Fig. 7 a schematic cross-section through a further embodiment of a device for embedding components in a layer, Fig. 8 a schematic partial view of an underside of the support plate of the Fig. 7, Fig. 9 a schematic cross section through a further embodiment of a device for embedding components in a layer, Fig. 10 a schematic partial view of the printing plate of the Fig. 9, Fig. 11 a schematic cross-section through a further embodiment of a device for embedding components in a layer, Fig. 12 a schematic partial section through a layer with embedded components, Fig. 13 a schematic partial view of a top side of the layer of Fig. 12, and Fig. 14 a schematic partial section through a further layer with embedded components.

[0021] Fig. 1 shows a schematic cross-section through a device for embedding optoelectronic components 1 in a layer. A molding tool 2 is provided, which in the illustrated embodiment has a cover plate 3 and a support plate 4. In addition, a film 5 is arranged on the underside of the support plate 4. The film 5 covers the entire underside of the support plate 4 and is thus arranged between the support plate 4 and the components 1. Depending on the selected embodiment, the film 5 can be omitted. The optoelectronic components 1 are designed, for example, as radiation-emitting components. For example, the optoelectronic components 1 can be designed in the form of light-emitting diodes. The components 1 are arranged on a carrier 6. The support plate 4 is made of a resilient material in the illustrated embodiment.For example, the support plate 4 can be formed from spring steel. The support plate 4 has a substantially flat underside 7 when not under load. The underside 7 of the support plate 4 is arranged on the upper sides 8 of the components 1. Depending on the selected embodiment, the film 5 is arranged between the support plate 4 and the components 1. The film 5 can be formed from an elastic material.

[0022] Support elements 10 of the printing plate 3 are arranged on an upper side 9 of the support plate 4. The support elements 10 extend in the form of pins from an underside of the printing plate 3. The support elements 10 are of equal length and are arranged in a predetermined grid. The support elements 10 can be arranged in a predetermined grid. The printing plate 3 is arranged on the upper side of the support plate 4 in such a way that at least some of the support elements 10, in particular all of the support elements 10, are arranged laterally of the components 1 in regions between the components 1.

[0023] Pressure is exerted on the pressure plate 3 in the direction of the support plate 4. The support elements 10 press the support plate 4 against the upper sides 8 of the components 1. Due to the design of the support plate 4 from a resilient material, the underside 7 of the support plate 4 can bend between the components 1 in the direction of a gap 11. Due to the resilient design of the support plate 4, height differences between the upper sides 8 of the components 1 or differently inclined upper sides 8 of the components 1 can be better covered with the support plate 4. To form the layer, molding material is introduced, in particular injected, into the gap 11 between the components 1 and the carrier and the support plate 4. Depending on the selected embodiment, an injection molding process, in particular a molding process, can be used to introduce the molding material into the gap 11.In addition, the support plate 4 can have a surrounding frame 12 that rests on the carrier 6 and laterally seals the intermediate space 11. However, an opening (not shown) is provided in the carrier 6 or in the frame 12 through which the molding material can be introduced. For example, plastic or molding material, in particular a silicon-glass composite mixture, can be used as the molding material. After the layer has cured, the molding tool 2 with the film 5 can be removed from the layer with the embedded components 1.

[0024] Fig. 2 shows a schematic view of a partial section of an underside of the printing plate 3. The support elements 10 that protrude from the underside of the printing plate 3 are shown schematically.

[0025] Fig. 3 shows a schematic representation of an underside of the support plate 4 with a transparent film 5 that covers the entire support plate 4.

[0026] Fig. Figure 4 shows a schematic representation of the arrangement of the components 1 in the form of larger squares and the arrangement of the support elements 10 in the form of smaller squares. In the illustrated embodiment, the components 1 are arranged in a first uniform grid. The support elements 10 are arranged in a second uniform grid, with the support elements 10 each being arranged between the components 1. In this way, a uniform pressure distribution on the support plate 4 and thus on the upper surfaces of the components 1 can be achieved.

[0027] Fig. Figure 5 shows a schematic cross-section through another device that can be used for embedding optoelectronic components in a layer. The arrangement essentially corresponds to the arrangement of Fig. 1, but in this embodiment the support plate 4, in contrast to the embodiment of the Fig. 1 has support blocks 13 on its underside. The support blocks 13 are arranged on the upper sides 8 of the components 1. The support blocks 13 have support surfaces 17 that cover at least the entire upper side 8 of the components 1. Furthermore, depending on the selected embodiment, a film 5 can be provided between the support blocks 13 and the components 1, as shown.

[0028] Fig. 6 shows a schematic partial section of the underside of the support plate 4 with the support blocks 13. In this embodiment, the support plate 4 can be made of a resilient or a rigid material. The support blocks 13 can be resiliently connected to a base plate 14 of the support plate 4. Thus, in this embodiment, the support plate 4 has a base plate 14, from the underside of which the support blocks 13 protrude. The support blocks 13 thus transfer the pressure of the pressure plate 3 directly to the upper sides 8 of the components 1. Depending on the selected embodiment, the support blocks 13 can be resiliently connected to the base plate 14. For this purpose, the support blocks 13 can have a correspondingly thin cross-section, at least in the transition area to the base plate 14, so that pivoting of the support blocks 13 relative to the base plate 14 is possible.This allows for easy compensation of different inclinations of the top surfaces 8 of the components 1. The support blocks 13 are arranged in the same grid as the components 1 on the carrier 6. Depending on the design, one support surface 17 of a support block 13 can also cover several components 1.

[0029] Fig. Fig. 7 shows a further embodiment of a device for embedding optoelectronic components 1 in a layer, this device being constructed essentially according to Fig. 5. The device differs from the device of the Fig. 5 in the structure of the support plate 4. In this embodiment of the support plate 4, the support blocks 13 are connected to the base plate 14 via spring elements 15. The spring elements 15 can be designed, for example, in the form of disc springs, leaf springs, or lens springs, or in other forms. The arrangement of the spring elements 15 between the support blocks 13 and the base plate 14 improves the resilient mounting of the support blocks 13. This allows for compensation of greater inclinations and / or greater height differences between the upper sides 8 of the components 1. The spring elements 15 can be glued and / or welded to the base plate 14 and / or to the support blocks 13.

[0030] Fig. 8 shows a schematic partial view of the underside of the support plate 4 of the Fig. 7. For better illustration, the spring elements 15 are shown larger than the support blocks 13. This illustration does not necessarily correspond to the realized embodiments of the support blocks 13 and the spring elements 15.

[0031] Fig. 9 shows a schematic cross section through a further embodiment of a device for embedding optoelectronic components in a layer, this device being essentially similar to the device of Fig. 5. However, this device differs from the device of the Fig. 5 in that the printing plate 3 does not have any support elements 10, but has a flat underside.

[0032] Fig. 10 shows a schematic plan view of the underside of the printing plate 3. In this embodiment, the provision of support elements 10 is not necessary due to the resilient mounting of the support blocks 13 on the base plate 14 of the support plate 4. In this embodiment, the support plate 4, in particular the base plate 14, can also be formed from a resilient material.

[0033] Fig. 11 shows a schematic cross section through a further embodiment of a device for embedding optoelectronic components in a layer, this device being essentially similar to the device of Fig. 7. In contrast to the embodiment of the Fig. 7, the pressure plate 3 is also in this embodiment in the form of a plate with a flat underside according to Fig. 10. The spring-loaded mounting of the support blocks 13 by means of the spring elements 15 on the base plate 14 of the support plate 4 enables the use of a simpler pressure plate 12.

[0034] Fig. Figure 12 shows a schematic cross section through an arrangement with a carrier 6 on which components 1 are arranged, wherein the components 1 are embedded in a layer 16 of molding material. This arrangement was, for example, produced with one of the devices of Fig. 1 to 11 produced.

[0035] Fig. 13 shows a schematic plan view of a section of an arrangement with a carrier 6 on which components 1 are arranged, wherein the components 1 are embedded in a layer 16 of molding material.

[0036] Depending on the device used, the layer 16 may also extend beyond the top surfaces 8 of the components 1. However, due to the devices used, the top surfaces 8 of the components 1 themselves are prevented from being covered by the layer 16.

[0037] Fig. Fig. 14 shows a cross section through a corresponding arrangement of a carrier 6 on which components 1 are arranged, wherein the layer 16 projects beyond the upper sides 8 of the components 1. This arrangement was, for example, produced with a device according to Fig. 5, Fig. 7, Fig. 9 or Fig. 13 manufactured.

[0038] The invention has been illustrated and described in more detail using the preferred embodiments. LIST OF REFERENCE SYMBOLS 1 component 2 mold tool 3 printing plate 4 support plate 5 Slide 6 carriers 7 Underside of the support plate 8 Top of the component 9 Top of the support plate 10 support element 11 space 12 frames 13 support block 14 Base plate 15 Spring element 16 shift 17 Support surface support block

Claims

[1] A method for embedding optoelectronic components in a layer, wherein the components are arranged next to one another at intervals on a carrier, wherein a molding tool with a support plate is provided, wherein the support plate has resilient support areas on a lower side, wherein the support plate with the resilient support areas is placed on upper sides of the components, wherein a space between the components, the carrier and the support plate is filled with a molding material, wherein the molding material is cured to form the layer, and wherein the molding tool is removed from the layer and the embedded components, wherein the molding tool has a pressure plate, wherein the pressure plate has support elements on a lower side, wherein the support elements are spaced apart from one another, wherein the pressure plate with the support elements rests on an upper side of the support plate,whereby the pressure plate with the support elements presses the support plate against the components when the molding material is filled into the space. [2] Method according to claim 1, wherein the support plate is formed from a resilient material, wherein the underside of the support plate represents the resilient support areas, and wherein the support elements of the pressure plate are arranged at least partially laterally offset from the components. [3] Method according to one of the preceding claims, wherein the support plate has support blocks on the underside, wherein the support blocks are arranged in the same grid as the components, wherein the support blocks have the support surfaces, wherein in each case a support surface of a support block is arranged above an upper side of a component. [4] A method according to claim 3, wherein the support blocks are resiliently connected to the support plate. [5] Method according to claim 4, wherein the support blocks are connected to the support plate via spring elements. [6] Method according to one of the preceding claims, wherein molding material is filled into the space between the component, the carrier and the support plate as molding material. [7] Method according to one of the preceding claims, wherein a film is arranged between the molding tool and the components, wherein the film rests on the upper sides of the components, wherein the film is arranged between the intermediate space and the molding tool, and wherein the film protects the molding tool against wetting with molding material. [8] Molding tool for embedding optoelectronic components (1) in a layer (16), comprising a support plate (4), wherein the support plate (4) has resilient support regions (7, 13), wherein the resilient support regions (7, 13) are provided to be placed on components (1) arranged on a carrier (6), wherein the support plate (4) is designed to delimit an intermediate space (1) between the support plate, the components and the carrier for filling in molding material, comprising a pressure plate (3), wherein the pressure plate (3) has support elements (10) on a bottom side, wherein the support elements (10) are arranged at a distance from each other, wherein the pressure plate (3) rests with the support elements (10) on a top side (9) of the support plate (4), wherein a bottom side (7) of the support plate (4) represents the resilient support regions which are placed on the components (1), and wherein the support plate (4) is designed is,to bend in areas between the components (1). [9] Molding tool according to claim 8, wherein the support plate (4) has support blocks (13) on the underside (7), wherein the support blocks (13) are arranged at a distance from one another, wherein the support blocks (13) have support surfaces (17) for resting on the components (1). [10] Molding tool according to claim 9, wherein the support blocks (13) are resiliently connected to a base plate (14) of the support plate. [11] Molding tool according to one of claims 8 to 10, wherein the support plate (4) is formed from a resilient material, and wherein in particular the support plate is formed from a spring steel. [12] Molding tool according to one of claims 10 or 11, wherein the support blocks (13) are connected to the support plate (4) via spring elements (15) of a base plate (14). [13] Moulding tool according to one of claims 8 to 12, wherein a film (5) is arranged on the underside (7) of the support plate (4), wherein the film (5) is designed to rest on the components (1) and to protect the support plate (4) against wetting with moulding material.

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