Optoelectronic component and process

Abstract

Optoelectronic component (100, 101), comprising a lead frame (110), a molded body (140) connected to the lead frame (110), and an optoelectronic semiconductor chip (150) arranged on the lead frame (110), wherein the lead frame (110) has an alignment opening (130), wherein the molded body (140) has a recess (143, 146, 147) via which the lead frame (110) is exposed in the region of the alignment opening (130), and wherein the molded body (140) has a further recess (141) exposing the lead frame (110), within which the optoelectronic semiconductor chip (150) is arranged on the lead frame (110).

Description

[0001] The invention relates to an optoelectronic component and a method for producing an optoelectronic component.

[0002] This patent application claims priority from German patent application DE 10 2013 225 552 A1.

[0003] An optoelectronic component can comprise one or more optoelectronic semiconductor chips and a carrier serving as a housing. The semiconductor chips can be designed to generate light radiation. The semiconductor chips can be light-emitting diode (LED) chips. Conversion elements for radiation conversion can be arranged on the LED chips. The carrier can comprise a lead frame overmolded with a molded body, which forms rear connection surfaces. In this embodiment, the component is suitable for surface mounting (SMT, Surface Mounting Technology). Here, the component can be placed on a circuit board printed with solder, and a reflow soldering process can be performed to solder the component to the circuit board. During the soldering process, the SMT component can float into its final position on the circuit board.

[0004] A surface-mount optoelectronic component can be used, for example, in a motor vehicle headlight or in a projector. In such applications, the component can be combined with a downstream secondary optics system. Typically, the aim is to position the secondary optics with high precision relative to the component's light-emitting surfaces. To achieve smaller tolerances and suppress deviations due to floating during soldering, it may be considered to position the component as precisely as possible on the circuit board and to fix it during the soldering process. The decisive factor here is the position of the light-emitting surfaces (usually the semiconductor chips). These often cannot be accurately detected using image recognition.Therefore, other features, such as markings on the mold body, component edges, or similar, are used to determine the positioning. However, such features can also fluctuate in their position relative to the semiconductor chips, which can result in a suboptimal tolerance chain overall.

[0005] DE 11 2011 103 147 T5 relates to a multi-chip LED device comprising a substrate on which LED chips and a lens are arranged. The substrate has a structured metal layer for connecting and supplying power to the LED chips. The structured metal layer may have holes and notches for alignment.

[0006] US 2012 / 0 138 967 A1 relates to an LED package and a method for its production. In the method, a lead frame is created by etching a metallic starting layer. Marks used for alignment are formed on the lead frame. Further steps include arranging LED chips on the lead frame, forming a resin body encapsulating the LED chips on the lead frame, and dicing.

[0007] US 2010 / 0 053 929 A1 describes an LED package and a related manufacturing method. In the method, a circuit board with LED chips is provided, and a cover having conductor structures is connected to the circuit board. The circuit board and the cover may have reference markings.

[0008] US 2007 / 0 235 845 A1 describes a surface-mount component comprising a leadframe with conductor elements, a housing body with a recess, and an optoelectronic element arranged on a conductor element in the recess. The housing body has markings for alignment.

[0009] US 2006 / 0 180 824 A1 describes an LED device with a metallic heat-dissipating element and an LED chip arranged on the heat-dissipating element. The LED device has metallic mounting sections for holding the heat-dissipating element, metallic conductor sections for supplying power to the LED chip, and a housing body with a recess. The mounting sections have holes for receiving a portion of the housing body. The LED chip and the heat-dissipating element are arranged within the recess of the housing body. The conductor sections, as well as the mounting sections in the region of the holes, are partially exposed via the recess in the housing body.

[0010] The object of the present invention is to provide a solution for an improved optoelectronic component.

[0011] This object is achieved by the features of the independent patent claims. Further advantageous embodiments of the invention are specified in the dependent claims.

[0012] According to one aspect of the invention, an optoelectronic component is proposed. The optoelectronic component comprises a leadframe, a molded body connected to the leadframe, and an optoelectronic semiconductor chip arranged on the leadframe. The leadframe has an alignment opening. The molded body has a recess through which the leadframe is exposed in the region of the alignment opening.

[0013] The optoelectronic component, which may be suitable for surface mounting (SMT, Surface Mounting Technology), can be used, for example, in a motor vehicle headlight or in a projector. With such potential applications in mind, the component is designed to emit light radiation. The optoelectronic semiconductor chip of the component is designed to generate light radiation. Alternatively, an embodiment of the component may also be considered in which the optoelectronic semiconductor chip is designed to detect or absorb light radiation.

[0014] The component can be configured such that the optoelectronic semiconductor chip arranged on the leadframe and the alignment opening present on the leadframe have a precise position relative to each other. This can be used in several ways to enable precise alignment with a short tolerance chain.

[0015] The optoelectronic component can, for example, be soldered onto a circuit board with high precision. For this purpose, the component can be precisely placed on the circuit board using the alignment opening and fixed during a reflow soldering process. In this way, the optoelectronic semiconductor chip can assume a specified position on the circuit board with high precision. With regard to a design of the semiconductor chip for generating light radiation, it is correspondingly possible for a light-emitting area provided by the semiconductor chip to assume a specified position on the circuit board.

[0016] The alignment opening can further be used to position another component with high precision relative to the semiconductor chip. For example, the alignment opening can be used to precisely position a secondary optic relative to a light-emitting surface provided by the semiconductor chip in a configuration of the semiconductor chip for generating light radiation.

[0017] The existence of a defined relative position between the optoelectronic semiconductor chip and the alignment opening of the leadframe can be achieved in different ways. For example, it is possible to align the semiconductor chip directly with the alignment opening during component manufacture. This allows the shortest possible tolerance chain to be achieved.

[0018] The optoelectronic component can also be manufactured by arranging the optoelectronic semiconductor chip on the leadframe using at least one other alignment structure of the leadframe, which is no longer present in the finished component. The alignment opening can be created together with the other alignment structure and therefore have a precise position, possibly with a minimal tolerance deviation, with respect to the other alignment structure. This therefore applies correspondingly to the relative position between the alignment opening and the semiconductor chip.

[0019] A further advantage is that the design of the optoelectronic component with the alignment aperture does not result in additional manufacturing costs compared to a conventional component (without an alignment aperture). This is because the alignment aperture can be created during component manufacturing along with the rest of the leadframe structure.

[0020] The alignment opening can also be used to secure the optoelectronic component. The fixation can be achieved on a circuit board on which the optoelectronic component can be arranged. The fixation can be achieved, for example, using a screw, a pin, or another fastening device that can be inserted into the alignment opening.

[0021] The alignment opening or the recess in the molded body through which the alignment opening is exposed can also be used, for example, to mechanically align and / or fix another component, such as a secondary optic, to the optoelectronic component. For this purpose, the component or secondary optic may be provided with, for example, an alignment pin or other suitable alignment or fastening structure that can be inserted into the recess or the alignment opening.

[0022] Further possible embodiments of the optoelectronic component are described in more detail below.

[0023] In one possible embodiment, the alignment opening of the lead frame is circular. This can facilitate precise alignment, as the center of the circular alignment opening can be used as a reference point for alignment. The position of the center point can be independent of the size of the alignment opening.

[0024] However, it is also possible for the alignment opening to have a shape other than circular. One possible example is a cross shape.

[0025] The recess in the mold body, through which the alignment opening of the lead frame is visible and can be used for alignment, can have different shapes. For example, a round, circular, or oval geometry is possible. Such a design enables simple production of the optoelectronic component. For example, the mold body can be produced using a molding process. A round recess enables easy demolding after the molding process.

[0026] According to the invention, the molded body has a further recess that exposes the lead frame. The optoelectronic semiconductor chip is arranged on the lead frame within this recess.

[0027] The optoelectronic semiconductor chip can be a light-emitting diode (LED) chip designed to generate light radiation. A conversion element for radiation conversion can optionally be arranged on the semiconductor chip.

[0028] In a further embodiment, the optoelectronic component comprises a plurality of, for example, two, optoelectronic semiconductor chips. Accordingly, the plurality of semiconductor chips can have a defined, precise position relative to the alignment opening. The plurality of semiconductor chips can be arranged in a common recess of the molded body on the lead frame. The plurality of semiconductor chips can be configured to generate or detect light radiation. In one embodiment of the semiconductor chips for generating radiation, a separate conversion element for radiation conversion can be arranged on each of the semiconductor chips.

[0029] The leadframe may have multiple leadframe sections or be structured into multiple leadframe sections. The multiple leadframe sections, or a portion thereof, may be electrically separated from one another and mechanically connected via the molded body. The multiple leadframe sections may form connection pads on a rear side of the optoelectronic component, with which the component can be soldered to a printed circuit board. The alignment opening may, as stated above, be produced together with the remaining structuring of the leadframe, and thus together with the rear connection pads of the component.

[0030] The alignment hole may be located in the area of a connection surface.

[0031] The alignment opening can be created on a separate leadframe section that is designed solely for the alignment opening. However, it is also possible for the alignment opening to be created on a leadframe section that also serves, for example, to support or contact a semiconductor chip. The following configurations may be considered for this purpose.

[0032] In a further embodiment, the leadframe comprises a first leadframe section and a second leadframe section. The optoelectronic semiconductor chip is arranged at least on the first leadframe section.

[0033] With regard to the aforementioned embodiment, it can be provided, for example, that the optoelectronic semiconductor chip has a front-side contact and a back-side contact, and that the semiconductor chip is arranged on the first leadframe section. The back-side contact can electrically and mechanically connect the semiconductor chip to the first leadframe section. A connection can be established via a suitable connecting layer, for example a solder layer or a layer of an electrically conductive adhesive. The front-side contact of the semiconductor chip can be electrically connected to the second leadframe section via a suitable connecting structure, for example in the form of a bonding wire.

[0034] Other configurations may also be considered for the optoelectronic semiconductor chip. For example, the semiconductor chip may have two front-side contacts. The semiconductor chip may be arranged on the first leadframe section, and one of the two front-side contacts may be electrically connected to the first leadframe section via a connecting structure. The other of the two front-side contacts may be electrically connected to the second leadframe section via a further connecting structure. The connecting structures may be in the form of bond wires.

[0035] The optoelectronic semiconductor chip can further comprise, for example, two rear contacts. The semiconductor chip can be a so-called flip chip. In this configuration, the semiconductor chip can be arranged on the first and second leadframe sections. The semiconductor chip can be electrically and mechanically connected to the first leadframe section with one of the rear contacts, and the semiconductor chip can be electrically and mechanically connected to the second leadframe section with the other rear contact. The connection can be established in each case via a suitable connecting layer, for example, a solder layer or a layer of electrically conductive adhesive.

[0036] If the optoelectronic component comprises a plurality of optoelectronic semiconductor chips, the leadframe of the component can comprise a suitable number of leadframe sections or a plurality of first and second leadframe sections for the plurality of semiconductor chips. Each semiconductor chip can be arranged on at least one leadframe section in the manner described above and electrically connected to two leadframe sections.

[0037] It may be provided that the alignment opening is formed on one of the first and second leadframe sections or on one of the first and second leadframe sections.

[0038] Furthermore, it is conceivable for the leadframe to have a further leadframe section on which the alignment opening is formed. In this embodiment, it may be possible to not use the further leadframe section for soldering when soldering the optoelectronic component to a circuit board.

[0039] In a further embodiment, the leadframe has a plurality of alignment openings. It is possible to perform the above-mentioned alignment processes, for example, aligning the optoelectronic semiconductor chip(s) on the leadframe, aligning the optoelectronic component on a circuit board, and / or aligning a further component or a secondary optic with respect to the component, based on all of the component's plurality of alignment openings. This allows an alignment process to be performed with high accuracy and reliability. The plurality of alignment openings of the leadframe can each be circular, for example. Furthermore, the leadframe of the component can be formed with three alignment openings, for example.

[0040] When designing the optoelectronic component with multiple alignment openings, features and details described above for a (single) alignment opening can be applied analogously. Furthermore, it is possible for some or all of the multiple alignment openings to be provided on different leadframe sections. It is also possible for some or all of the multiple alignment openings to be formed on a common leadframe section. Furthermore, separate, exposing recesses can be formed in the molded body for each of the multiple alignment openings, or a common recess can be provided in the molded body for some or all of the multiple alignment openings.

[0041] In a further embodiment, the leadframe is a leadframe formed by etching. The alignment opening(s) can be created, together with the remaining structure of the leadframe, during the etching process. This allows the alignment opening(s) to be fixed to the leadframe with high precision and thus positioned.

[0042] The optoelectronic component can have further components. For example, a recess in the molded body, within which at least one semiconductor chip can be arranged, can be filled with a potting compound. This can be a reflective potting compound. The recess can be filled with the reflective potting compound in such a way that only a front side of the at least one semiconductor chip or of at least one conversion element arranged thereon is exposed. This can ensure that, during operation of the component designed for light emission, light is emitted only via this front side(s).

[0043] According to a further aspect of the invention, a method for producing an optoelectronic component is proposed. The component has the structure described above or a structure according to one or more of the embodiments described above. The method comprises providing a leadframe. The provided leadframe has an alignment opening. The method further comprises forming a molded body connected to the leadframe. The molded body has a recess via which the leadframe is exposed in the region of the alignment opening. The method further comprises arranging an optoelectronic semiconductor chip on the leadframe.

[0044] The optoelectronic component manufactured according to the method can prove advantageous in several respects. The alignment opening and the optoelectronic semiconductor chip can have a precise position relative to one another. Therefore, using the alignment opening, it is possible to precisely mount the component on a circuit board with a predetermined position of the semiconductor chip on the circuit board. With the aid of the alignment opening, it is also possible to position another component, such as a secondary optic, with high accuracy relative to the semiconductor chip.

[0045] In one possible embodiment of the method, the alignment opening of the lead frame is used to align the optoelectronic semiconductor chip when arranging the optoelectronic semiconductor chip on the lead frame. If the alignment opening, as stated above, is also used when arranging the optoelectronic component on a printed circuit board and when positioning another component or secondary optics, the shortest possible tolerance chain can be achieved in this way.

[0046] In a further embodiment of the method, providing the leadframe comprises providing a metallic starting layer and structuring the metallic starting layer. The leadframe thus produced may have multiple leadframe sections. The alignment opening is formed during structuring. This allows the alignment opening to be fixed to the leadframe with high precision.

[0047] This applies, for example, to a possible embodiment in which the structuring comprises a front-side and a back-side etching of the metallic starting layer. The alignment opening is formed by the back-side etching. The back-side etching can simultaneously form the back-side connection pads of the lead frame, which can be used to solder the component to a printed circuit board. Thus, the alignment opening can be created with a precise position relative to the connection pads.

[0048] The leadframe can also be provided or structured in other ways. For example, mechanical structuring of the metallic starting layer is possible, using processes such as punching and / or embossing. In this way, the alignment opening can also be formed together with the remaining structuring of the leadframe and thus together with the rear connection pads of the leadframe.

[0049] After structuring, the leadframe can also be coated with a metallic coating. The coating can be created, for example, by electrochemical deposition or electroplating. The coating can make the leadframe suitable for soldering and connecting a bond wire. Forming the coating can be considered, for example, for a metallic starting layer made of copper. The coating can, for example, comprise a layer stack of Ni, Pd, or Au.

[0050] Forming the molded body can involve overmolding the structured leadframe with a housing or molding compound made of a plastic material. A molding process can be performed for this purpose. In this embodiment, the arrangement of leadframe and molding compound can be a so-called premold housing.

[0051] In the manufacturing method, further features and details explained above with reference to the optoelectronic component can also be applied. For example, it is possible to provide the leadframe with multiple alignment openings, so that precise alignment can be achieved using the multiple alignment openings of the component. Furthermore, the component can be implemented with multiple optoelectronic semiconductor chips.

[0052] According to the invention, the molded body is formed such that the molded body has a further recess exposing the leadframe, within which the optoelectronic semiconductor chip is arranged on the leadframe. In an embodiment of the optoelectronic component with a plurality of optoelectronic semiconductor chips, the plurality of semiconductor chips can be arranged within the further recess on the leadframe. The further recess can be filled with a potting compound, for example, a reflective potting compound.

[0053] With regard to the method, it is further noted that it is possible to carry out the method in such a way that a coherent assembly is produced from a plurality of optoelectronic components, each of which has at least one optoelectronic semiconductor chip. In this case, the leadframe can be provided with a plurality of alignment openings assigned to the individual components. One or more alignment openings can be assigned to each component. Furthermore, the molded body can be produced with a plurality of recesses for the alignment openings and for the semiconductor chips. After the coherent assembly has been produced, the assembly can be separated into separate optoelectronic components.

[0054] When manufacturing multiple optoelectronic components in parallel, the leadframe can be provided with additional alignment structures assigned to all components to determine the position of the semiconductor chips. Such global or universal alignment structures can also be present in the form of openings in the leadframe. The universal alignment structures can be formed together with the alignment openings assigned to the individual components, allowing them to be positioned with a small tolerance deviation relative to one another. The arrangement of semiconductor chips on the leadframe can be carried out using the universal alignment structures.Because the universal alignment structures and the individual alignment openings can be precisely positioned relative to each other, the semiconductor chips can also assume a precise position relative to the individual alignment openings of the components. During singulation, not only can the components be separated, but a portion of the assembly containing the universal alignment structures can also be separated from the components. Because the semiconductor chips and the alignment openings of the components can be precisely positioned relative to each other, the alignment openings can be used for precise alignment.

[0055] Alternatively, it is possible to arrange the semiconductor chips on the leadframe using the individual alignment openings of the components. This eliminates the need to form the leadframe with universal alignment structures.

[0056] The advantageous embodiments and further developments of the invention explained above and / or reproduced in the subclaims can - except, for example, in cases of clear dependencies or incompatible alternatives - be used individually or in any combination with one another.

[0057] 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 exemplary embodiments, which are explained in more detail in conjunction with the schematic drawings. They show: Fig. 1 is a side view of an optoelectronic component having an alignment opening in a separate portion of a lead frame; Fig. 2 a top view of a front side of the optoelectronic component of Fig. 1; and Fig. 3 a side view of another optoelectronic component in which an alignment opening is formed in a portion of a lead frame intended to support a semiconductor chip.

[0058] The following figures describe possible embodiments of surface-mount optoelectronic components. These are designed to enable alignment with high accuracy and reliability. This includes, for example, precise mounting on a printed circuit board. Another example is the precise positioning of a secondary optic.

[0059] The embodiments shown in the figures and described below can be manufactured using processes known from semiconductor technology and from the manufacture of optoelectronic components. Materials commonly used in this field can also be used, so this will only be discussed in part. Likewise, it is conceivable that the components may contain further components and structures in addition to those shown and described. It is further noted that the figures are merely schematic in nature and are not to scale. In this sense, components and structures shown in the figures may be exaggerated or reduced in size for the sake of clarity.

[0060] Fig. 1 shows a schematic side view of a surface-mount optoelectronic component 100. A schematic top view of a front side of the component 100 is shown in Fig. 2. The SMT component 100, which is implemented in the form of a so-called package, comprises two optoelectronic semiconductor chips 150 for generating light radiation and a carrier serving as a housing. The carrier comprises a metallic leadframe 110, which is overmolded by a housing or molded body 140.

[0061] The metallic lead frame 110 has a plurality of lead frame sections 111, 112, 113, 114, 115, 116, 117. As shown in Fig. As shown in Figure 2, the leadframe sections 111, 112, 113, 114, 115, 116, 117 are partially concealed by the molded body 140 (and the semiconductor chips 150). The leadframe sections 111, 112, 113, 114, 115, 116, 117 can be electrically separated from each other and mechanically connected via the molded body 140.

[0062] The four lead frame sections 111, 112, 114, 115 serve to support and electrically connect the two semiconductor chips 150 (cf. Fig. 2). An alignment opening 130, circular in plan view, is formed on each of the three other leadframe sections 113, 116, 117. The three alignment openings 130 of the component 100 can be used for precise alignment. This can take advantage of the fact that the alignment openings 130 can have a minimal tolerance deviation from structures used in the manufacture of the component 100 to determine or fix the position of the semiconductor chips 150 in the component 100. Further details on this will be described in more detail below.

[0063] A design for the Fig. 2 in the area of the left side of the component 100, the three lead frame sections 111, 112, 113 are shown schematically from the side in Fig. 1. The leadframe sections 111, 112, 113 are flush with the molded body 140 on a rear side of the component 100, and form exposed connection surfaces 125 (solder pads) in this area. Furthermore, the leadframe sections 111, 112, 113 are stepped laterally at the edge and have recesses 119 on the edge or around the edge. This structure enables the molded body 140 to be interlocked with the leadframe 110, thus creating a mechanically strong connection. The molded body 140 or parts thereof border, as shown in Fig. 1, at the edge and in the region of the recesses 119, to the leadframe sections 111, 112, 113, and can also cover part of the leadframe sections 111, 112, 113 at the front edge. A comparable design (stepped edge shape, exposed connection surfaces 125, etc.) is also present in the other leadframe sections 114, 115, 116, 117 not shown from the side. The leadframe 110 and thus the component 100 can be soldered to a printed circuit board (not shown) via the connection surfaces 125 of the leadframe sections 111, 112, 113, 114, 115, 116, 117.

[0064] As in Fig. 2, the molded body 140 has four recesses 141, 143, 146, 147, whereby the leadframe sections 111, 112, 113, 114, 115, 116, 117 are partially exposed on a front side opposite the rear side. With respect to the three leadframe sections 113, 116, 117 provided with the alignment openings 130, the molded body 140 has three corresponding recesses or cavities 143, 146, 147 (see also Fig. 1 for the leadframe section 113). The recesses 143, 146, 147 have a round or oval geometry in plan view. The leadframe sections 113, 116, 117 are exposed in the area of the alignment openings 130 via the recesses 143, 146, 147. In this way, the alignment openings 130 are visible on the front or chip side and can be used for alignment.

[0065] The lead frame sections 111, 112, 114, 115 used to support and connect the semiconductor chips 150 are partially exposed on the front side via the further recess 141. The recess 141 has a more complex contour in plan view than the other recesses 143, 146, 147. The recess 141 has a rectangular partial area exposing the lead frame sections 111, 114, and two extending in the direction of the other lead frame sections 112, 115 (ie in Fig. 2 upwards) and exposing the lead frame sections 112, 115.

[0066] Based on Fig. 1 it is clear that the lead frame sections 111, 112 intended for one of the semiconductor chips 150 are exposed on the front side via the recess 141 of the molded body 140. In Fig. 1 further shows that in the region of the recess 141 and in a region adjacent to or between the leadframe sections 111, 112, a partial region 241 of the molded body 140 is present, which is connected to the leadframe sections 111, 112. The partial region 241 of the molded body 140 has a smaller height or layer thickness than a part of the molded body 140 surrounding the recess 141.

[0067] A comparable partial area 242 of the molded body 140 in the area of the recess 141 with the same (smaller) layer thickness is also present between the other leadframe sections 114, 115 and connected to them (only in Fig. 2). The partial regions 241, 242 of the molded body 140 have different contours in plan view.

[0068] As further stated in Fig. As shown in Figure 2, a further partial region 243 of the molded body 140 is located between the leadframe sections 111, 114 of the leadframe 110. The partial region 243 of the molded body 140 has a thin, strip-shaped contour in plan view. The partial region 243 can be flush with the leadframe sections 111, 114 at the front.

[0069] The optoelectronic semiconductor chips 150 of the component 100 are designed to generate light radiation. On each of the semiconductor chips 150, as shown in Fig. 2, a platelet-shaped conversion element 155 is arranged for radiation conversion. The conversion elements 155 can be attached to the semiconductor chips 150 using a radiation-permeable adhesive. The optoelectronic semiconductor chips 150 can be light-emitting diode chips. The semiconductor chips 150 can be surface emitters produced using thin-film technology, in which a substantial portion of the generated radiation can be emitted via a front surface (light exit side) and thus coupled into the conversion elements 155 arranged at this location.

[0070] The optoelectronic semiconductor chips 150 can be manufactured in a conventional manner and can comprise components not shown, such as a semiconductor layer sequence with an active zone for generating radiation. The semiconductor chips 150 further each comprise a rear contact and a front contact, via which electrical energy for generating radiation can be supplied to the semiconductor chips 150. The rear contacts serve to arrange the semiconductor chips 150 on the leadframe 110. Fig. The front contacts indicated in 2 are bond pads for connecting bond wires 159.

[0071] In Fig. 1 is a contact for one of the semiconductor chips 150 (left in Fig. 2) shown from the side. The respective semiconductor chip 150 is arranged on the front side of the leadframe section 111. The rear contact of the semiconductor chip 150 is electrically and mechanically connected to the leadframe section 111 via a connecting layer 158. The connecting layer 158 is, for example, a solder layer or a layer of an electrically conductive adhesive. The front contact of the semiconductor chip 150 is connected to the leadframe section 112 via a bonding wire 159. The bonding wire 159 extends over the partial region 241 of the molded body 140.

[0072] With regard to the other of the two semiconductor chips 150, comparable circumstances exist (see right in Fig. 2). This semiconductor chip 150 is arranged with the associated rear contact on the leadframe section 114. Furthermore, the front contact of the semiconductor chip 150 is connected to the leadframe section 115 via another bonding wire 159. The bonding wire 159 extends over the other partial region 242 of the molded body 140.

[0073] The conversion elements 155 arranged on the front side of the semiconductor chips 150 have, as shown in Fig. 2, each has a recess at a corner. In this way, the front-side contacts of the semiconductor chips 150, which are formed at the corners of the semiconductor chips 150, are freely accessible for contacting with the bond wires 159.

[0074] With the help of the conversion elements 155, the light radiation primarily generated by the semiconductor chips 150 can be at least partially converted. The primary light radiation emitted by the semiconductor chips 150 can be, for example, blue light radiation. The conversion elements 155 can be used to at least partially convert the primary light radiation into one or more light radiations of another wavelength range(s), for example, in the green to red spectral range. In this way, light radiation with a desired color, for example, white light radiation, can be generated, which can be emitted via the conversion elements 155. In this embodiment, the component 100 can be used, for example, in a headlight of a motor vehicle.

[0075] It may also be considered to design the optoelectronic component 100 in such a way that radiation is emitted only via the front sides of the conversion elements 155. This can be achieved by filling the recess 141 of the molded body 140 with a reflective potting compound 160, as shown in Fig. 1 by the dashed line. The encapsulating compound 160 can comprise a radiation-transmissive base material, for example, silicone, and reflective particles contained therein, for example, TiO2 particles. The semiconductor chips 150 and conversion elements 155 are surrounded by the encapsulating compound 160 such that only the front sides of the conversion elements 155 are exposed. The encapsulating compound 160 extends to the front sides of the conversion elements 155 and is also present between the semiconductor chips 150 and conversion elements 155.

[0076] In relation to Fig. 1 it is pointed out that the shaped body 140 outside the recess 141 deviates from the Fig. 1 may have a greater thickness. The molded body 140 may project beyond the front sides of the conversion elements 155 and thus the potting compound 160.

[0077] A possible manufacturing method for producing an optoelectronic component 100 is described below. In the method, a coherent assembly is formed from a plurality of similar components 100, which is subsequently separated. It should be noted that the aspects already mentioned above regarding individual component components and structures will not be described in detail again. Instead, reference is made to the above description.

[0078] In the method, a metallic starting layer made of copper is provided. The starting layer is structured into a lead frame 110. The structured lead frame 110 has lead frame sections 111, 112, 113, 114, 115, 116, 117 for each of the components 100 to be produced, as well as connecting structures for holding the lead frame sections 111, 112, 113, 114, 115, 116, 117 together (not shown). Lead frame sections 111, 112, 113, 114, 115, 116, 117 of different components 100 are connected in a suitable manner.

[0079] Structuring is carried out by etching the metallic starting layer on the front and back. In this way, the Fig. The lateral step shape of the leadframe sections 111, 112, 113, 114, 115, 116, 117 with the recesses 119, as explained in Figure 1, is created. The shape of the soldering or connection surfaces 125 is determined by the backside etching.

[0080] In the lead frame sections 113, 116, 117, recesses 135 are formed by the front-side etching (cf. Fig. 1 for the lead frame section 113). The front recesses 135 can be rectangular (cf. Fig. 2). The front-side recesses 135 have larger lateral dimensions than the alignment openings 130. The alignment openings 130 are formed by the back-side etching, and thus together with the back-side connection pads 125. In this way, the alignment openings 130 can be created with a precise position relative to the connection pads 125.

[0081] It is possible for the structured leadframe 110 to have one or more further sections (for example, at the edge) provided with global or universal alignment structures (not shown). The universal alignment structures can also be in the form of openings and can be created by backside etching. In this way, the universal alignment structures and the alignment openings 130 (three each) associated with the individual components 100 can be positioned precisely and with a small tolerance deviation relative to one another.

[0082] After patterning, the copper lead frame 110 is provided with a metallic coating by electroplating (not shown). This serves to make the lead frame 110 suitable for soldering and connecting bond wires 159. The coating can be a layer stack of Ni, Pd, or Au.

[0083] Subsequently, a molded body 140 connected to the leadframe 110 is produced. For this purpose, a molding process is carried out in which the leadframe 110 is overmolded with a molding or housing compound made of a suitable insulating plastic material, forming the molded body 140. The molded body 140 has four recesses 141, 143, 146, 147 per component 100, through which the leadframe 110 is partially exposed on the front side. The oval or round design of the recesses 143, 146, 147, but also of the recess 141 with partially rounded corners or edges (cf. Fig. 2) enables easy demoulding after the molding process.

[0084] Subsequently, processes such as arranging optoelectronic semiconductor chips 150 on the leadframe sections 111, 114 of the leadframe 110, arranging conversion elements 155 on the semiconductor chips 150, connecting bond wires 159, and filling the recesses 141 with a potting compound 160 are performed. Following this, the coherent assembly is separated into separate optoelectronic components 100. In this process, the molded body 140 and the leadframe 110, or the connecting structures of the leadframe 110, are severed. One or more parts of the leadframe 110 with the aforementioned universal alignment structures are also separated.

[0085] It is possible to arrange the semiconductor chips 150 on the lead frame 110 using the universal alignment structures. Since the universal alignment structures are precisely generated with respect to the alignment openings 130, the alignment openings 130 for each component 100 can have a precise position with respect to the associated semiconductor chips 150, and thus with respect to the light-emitting surfaces of the semiconductor chips 150 or the light-emitting front surfaces of the conversion elements 155. This property enables precise alignment of a manufactured component 100.

[0086] It is also possible to arrange the semiconductor chips 150 on the leadframe 110 directly using the alignment openings 130 individually assigned to the individual components 100. In this way, the alignment openings 130 and the semiconductor chips 150, or the light-emitting surfaces, can be positioned with high precision relative to one another. This enables alignment with the shortest possible tolerance chain. Forming the leadframe 110 with the universal alignment structures can also be omitted.

[0087] In an optoelectronic component 100 manufactured in this way, the alignment openings 130, which have a precise position relative to the semiconductor chips 150, can enable precise alignment in several respects.

[0088] For example, it may be provided to assemble a printed circuit board with the optoelectronic component 100 with high precision using the three alignment openings 130 (not shown). The printed circuit board to be assembled has contact areas (landing pads) corresponding to the soldering areas 125. For assembly, the contact areas of the printed circuit board can be provided with a solder or printed thereon. The component 100 can be placed on the printed circuit board with the connection areas 125 and electrically and mechanically connected to the printed circuit board in a reflow soldering process. Precise positioning can be achieved by precisely placing the component 100 on the printed circuit board using the alignment openings 130 and fixing it in place during the soldering process.In this way, the semiconductor chips 150 and the light-emitting surfaces of the component 100 can assume a predetermined position on the circuit board with high accuracy.

[0089] The circular shape of the alignment openings 130 can also prove advantageous for precise alignment. This is because the centers of the alignment openings 130 can be used for alignment. The position of the center of an alignment opening 130 is independent of the size of the respective alignment opening 130. In this way, manufacturing-related size deviations of the alignment openings 130 can have no or negligible influence on precise alignment.

[0090] The alignment openings 130 can also be used to secure the housing consisting of the lead frame 130 and the molded body 140, and thus the component 100, to the printed circuit board. For example, screws, pins, or other fastening means that can be inserted into the alignment openings 130 (not shown) can be used for fastening.

[0091] Depending on the application, it may be possible to combine the optoelectronic component 100 with a secondary optics system arranged downstream of the component 100 (not shown). The secondary optics system may comprise, for example, a lens and / or a reflector. With the aid of the alignment openings 130, it is possible to arrange the secondary optics system with high precision with respect to the semiconductor chips 150 and thus with respect to the light-emitting surfaces. The secondary optics system can be arranged, for example, on the component 100, the circuit board, or another component.

[0092] The alignment openings 130 and the recesses 113, 116, 117 of the molded body 140, via which the alignment openings 130 are exposed, can also be used to mechanically align the secondary optics to the optoelectronic component 100 and / or to secure it to the component 100. For this purpose, alignment pins or other structures can be provided on the secondary optics, for example, which can be inserted into the recesses 113, 116, 117 or into the alignment openings 130.

[0093] The optoelectronic component 100 can be manufactured, as described above, such that the leadframe sections 111, 112, 113, 114, 115, 116, 117 are separated from one another. This makes it possible to use only the soldering pads 125 of the four leadframe sections 111, 112, 114, 115, which are used to support and electrically connect the two semiconductor chips 150, for soldering the component 100 to a circuit board. However, for the three other leadframe sections 113, 116, 117, which are provided with the alignment openings 130, or their soldering pads 125, such use can be omitted.

[0094] It is possible to realize a component in which, unlike the component 100, lead frame sections are partially combined or connected to one another.

[0095] To illustrate such a variant, Fig. 3 shows a schematic side view of a further optoelectronic component 101. The component 101 represents a modification of the previously explained component 100. Corresponding features as well as identical and identically acting components, possible production, etc. are therefore not described in detail again below. For details, reference is instead made to the above description. Furthermore, it is pointed out that the component 101, in plan view, has a Fig. 2 can have a comparable form.

[0096] In the component 101 of Fig. 3, the leadframe section 111 is larger than that of the component 100 and additionally has an alignment opening 130. The leadframe section 111 also serves to support a semiconductor chip 150. The leadframe section 111 of the component 101 corresponds to a combination of the sections 111, 113 that are separate in the component 100. Furthermore, the component 111 has a leadframe section 112 for connecting a bonding wire 159.

[0097] The leadframe section 111 of the component 101 may, for example, be in the form of a planar section. Furthermore, it may be considered to design the component 101 such that the leadframe section 111 has a first subsection for supporting the semiconductor chip 150 and a second subsection with the alignment opening 130. The two subsections may be connected via a suitable connecting structure, which may be formed only in the Fig. 3. Such configurations may also apply to other leadframe sections of the component 101.

[0098] In this context, it is noted that the component 101, like the component 100, may have further leadframe sections, for example the sections 114, 115 for a further semiconductor chip 150 (cf. Fig. 2). In this case, it is possible for the leadframe section 115 of the component 101 to be implemented in the form of a connected configuration or combination of the sections 115, 117 of the component 100, and / or for the leadframe section 114 to be implemented in the form of a connected configuration or combination of the sections 114, 116.

[0099] The embodiments explained with reference to the figures represent preferred or exemplary embodiments of the invention. In addition to the described and illustrated embodiments, further embodiments are conceivable, which may include further modifications and / or combinations of features. For example, it is possible to use other materials instead of the materials specified above, and to replace the above information regarding the colors of light radiation with other information.

[0100] In a further possible modification, a component can be realized which has only one optoelectronic semiconductor chip, or more than two optoelectronic semiconductor chips.

[0101] Other numbers of alignment openings may also be considered. A component can therefore be implemented with fewer or more than three alignment openings. A component can also be designed with only one alignment opening.

[0102] In this context, it is also noted that it is possible to form one or more alignment openings with a structure that deviates from a circular shape. One possible example is an alignment opening that is cross-shaped when viewed from above.

[0103] Furthermore, components can be implemented in which other semiconductor chips are used instead of the semiconductor chips 150. These include, for example, semiconductor chips with two front-side contacts or semiconductor chips with two back-side contacts. A semiconductor chip with two front-side contacts can be arranged on a leadframe section, and one front-side contact can be connected to the same leadframe section via a bonding wire. The other front-side contact can be connected to another leadframe section via another bonding wire. A semiconductor chip with two back-side contacts can be arranged with the back-side contacts on two leadframe sections. The back-side contacts can be electrically and mechanically connected to the associated leadframe sections via corresponding connecting layers.

[0104] A further possible modification is a component which has at least one optoelectronic semiconductor chip designed to detect or absorb light radiation.

[0105] Variations in the manufacturing process may also be considered. For example, it is possible to create a leadframe by mechanically structuring a metallic starting layer. Processes such as stamping and / or embossing can be used for this purpose. Alignment openings (and possibly universal alignment structures) can also be formed in this way, along with the rest of the leadframe structure.

[0106] Furthermore, attention is drawn to the possibility that the components described above and their possible modifications can also be used in areas other than the automotive sector. For example, use in a projector is possible. For this purpose, it may be possible, for example, to design a component with several or three semiconductor chips for generating light radiation of different colors (e.g. RGB, i.e. red, green and blue). In this case, it is possible that no conversion elements are used, or that one or more conversion elements are arranged only on one or more individual semiconductor chips (e.g. in order to generate green mixed radiation by radiation conversion of blue primary radiation).Even in such an embodiment, (at least) one alignment opening in a lead frame of the component can be used for precise alignment, for example for positioning the component on a printed circuit board and positioning a secondary optic with respect to the component.

Claims

[1] Optoelectronic component (100, 101), comprising a lead frame (110), a molded body (140) connected to the lead frame (110), and an optoelectronic semiconductor chip (150) arranged on the lead frame (110), wherein the lead frame (110) has an alignment opening (130), wherein the molded body (140) has a recess (143, 146, 147) via which the lead frame (110) is exposed in the region of the alignment opening (130), and wherein the molded body (140) has a further recess (141) exposing the lead frame (110), within which the optoelectronic semiconductor chip (150) is arranged on the lead frame (110). [2] Optoelectronic component according to claim 1, wherein the optoelectronic semiconductor chip (150) is designed to generate light radiation. [3] Optoelectronic component according to one of the preceding claims, wherein the alignment opening (130) is circular. [4] Optoelectronic component according to one of the preceding claims, wherein the lead frame (110) has a first lead frame section (111, 114) and a second lead frame section (112, 115), wherein the optoelectronic semiconductor chip (150) is arranged at least on the first lead frame section (111, 114). [5] The optoelectronic component according to claim 4, wherein the alignment opening (130) is formed on one of the first and second leadframe portions (111, 112, 114, 115). [6] Optoelectronic component according to claim 4, wherein the lead frame (110) has a further lead frame portion (113, 116, 117) on which the alignment opening (130) is formed. [7] Optoelectronic component according to one of the preceding claims, wherein the lead frame (110) has a plurality of alignment openings (130). [8] Optoelectronic component according to one of the preceding claims, wherein the lead frame (110) has a plurality of lead frame sections (111, 112, 113, 114, 115, 116, 117) which form connection surfaces (125) on a rear side of the optoelectronic component. [9] Optoelectronic component according to claim 8, wherein the alignment opening (130) is located in the region of a connection surface (125). [10] A method for producing an optoelectronic component according to one of the preceding claims, comprising the method steps: Providing a lead frame (110), the lead frame (110) having an alignment opening (130); Forming a molded body (140) connected to the lead frame (110), wherein the molded body (140) has a recess (143, 146, 147) through which the lead frame (110) is exposed in the region of the alignment opening (130); and Arranging an optoelectronic semiconductor chip (150) on the lead frame (110), wherein the molded body (140) is formed such that the molded body (140) has a further recess (141) exposing the lead frame (110), and wherein the optoelectronic semiconductor chip (150) is arranged within the further recess (141) on the lead frame (110). [11] The method according to claim 10, wherein, when arranging the optoelectronic semiconductor chip (150) on the lead frame (110), the alignment opening (130) of the lead frame (110) is used to align the optoelectronic semiconductor chip (150). [12] The method of any of claims 10 or 11, wherein providing the leadframe (110) comprises providing a metallic seed layer and patterning the metallic seed layer, and wherein the alignment opening (130) is formed during patterning. [13] The method of claim 12, wherein patterning comprises front-side and back-side etching of the metallic starting layer, and wherein the alignment opening (130) is formed by the back-side etching.

Images