Optoelectronic component and production method therefor

An optoelectronic component and a method for producing an optoelectronic component are disclosed. In an embodiment the component includes a semiconductor chip, a molded body and an electrical through-contact constituting an electrically conductive connection through the molded body. The through-contact and the semiconductor chip are embedded alongside one another and are spaced apart in the molded body. A first contact pad of the through-contact is arranged at an underside of the molded body. A second contact pad of the through-contact is arranged at a top side of the molded body. The second contact pad is electrically conductively connected to the electrical contact of the semiconductor chip. The through-contact is arranged such that a molded body is arranged at least in a section between the first and second contact pads on a straight line between the first and second contact pads.

This patent application is a national phase filing under section 371 of PCT/EP2016/063113, filed Jun. 9, 2016, which claims the priority of German patent application 10 2015 109 333.2, filed Jun. 11, 2015, each of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The invention relates to an optoelectronic component and a method for manufacturing an optoelectronic component.

BACKGROUND

German Patent Application Publication No. DE 10 2009 036 621 A1 discloses a method for producing an optoelectronic semiconductor component, wherein an optoelectronic semiconductor chip with a through-contact is embedded into a molded body. The semiconductor chip comprises a first contact on an underside and a second contact on a top side. The second contact is electrically conductively connected to an upper contact pad of the through-contact. In this way, the second electrical contact of the top side of the semiconductor chip is led onto the underside of the molded body.

SUMMARY OF THE INVENTION

Embodiments of the invention provide an improved optoelectronic component and an improved method for producing an optoelectronic component.

One advantage of the proposed component is that the through-contact is better anchored in the molded body. This is achieved by virtue of the fact that the through-contact is configured in such a way that a molded body is arranged at least in a section between the first and second contact pads of the through-contact on a straight line. Consequently, a displacement of the through-contact in relation to the molded body may be at least made more difficult, in particular avoided.

In one embodiment, the through-contact is configured in the form of a folded or bent strip. A strong anchoring of the through-contact in the molded body is achieved as a result. Moreover, a relatively large conduction cross-sectional area for a low electrical resistance is provided by the configuration in the form of the strip.

In a further embodiment, the through-contact is configured in the form of a spiral. The spiral shape enables a relatively high elasticity. Moreover, the spiral shape is relatively insensitive toward damage. Depending on the embodiment chosen, the spiral shape may be arranged with a longitudinal axis parallel to an axis of the through-contact or perpendicular to the axis of the through-contact. The parallel arrangement offers a high stability. The perpendicular arrangement offers a large effective conduction cross-sectional area.

In a further embodiment, the through-contact is configured in the form of at least two or a plurality of conduction elements which are mechanically connected to one another. The conduction elements may be configured in the form of wires or strips. In this case, the ends of the conduction elements may form the first and second contact pads. The conduction elements may be twisted, for example, as mechanical connection. Twisted conduction elements in particular in the form of wires or strips are cost-effective and simple to produce. Moreover, a stable anchoring of the twisted conduction elements in the molded body may be achieved. Furthermore, a relatively large effective conduction cross section may be provided by a corresponding number of conduction elements.

The configuration of the through-contact in the form of a bent or folded strip or in the form of a spiral or in the form of connected conduction elements enables the configuration of a flexible, in particular an elastically and/or plastically deformable, contact element.

In a further embodiment, the through-contact comprises at least one cutout configured, for example, in the form of a depression, a protuberance or a hole. The cutout is filled with the molded body. A strong anchoring of the through-contact in the molded body is achieved in this way.

In a further embodiment, the through-contact configured in the form of a strip comprises at least two sections, in particular three sections, which are arranged substantially parallel to one another and are connected to one another via at least one intermediate section. A stable configuration of the through-contact with at the same time stable anchoring in the molded body is achieved in this way.

In a further configuration, the strip is configured such that it is meandering. A further improved anchoring of the strip in the molded body is achieved as a result.

In addition, embodiments of the invention relate to a method for producing the optoelectronic component.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

FIG. 1shows, in a schematic sectional illustration, a first method step for producing an optoelectronic component. A carrier1is provided. The carrier1may be formed, for example, from metal, such as, for example, copper or aluminum, or from ceramic or from a semiconductor material or from plastic. The carrier1may also be configured in the form of a film. Optoelectronic components2, which are configured, for example, in the form of a laser diode or a light emitting diode or in the form of a photosensor, are secured on the carrier1. In addition, a through-contact3is secured on the carrier1. The through-contacts3comprise a cutout50. By way of example, an adhesive layer may be used for the purpose of securing, said adhesive layer being applied on the top side of the carrier1. The optoelectronic semiconductor chip2may be arranged on the carrier1in such a way that a light emitting side bears on the carrier1.

Afterward, a molding compound4is applied on the carrier1, the semiconductor chips2and the through-contacts3being embedded into said molding compound. Moreover, the cutouts50are at least partly filled with molding compound4. The cutouts50may be configured in the form of holes, protuberances or indentations. Each through-contact may comprise at least one cutout50. A stronger anchoring of the through-contact3in the molding compound4is achieved as a result. The molding compound4may be applied by encapsulation by molding, enveloping, for example, by means of injection molding, casting, printing, lamination of a film or the like. This method state is illustrated inFIG. 2. Depending on the embodiment chosen, in this case both the semiconductor chips2and the through-contacts3may be overfilled with the molding compound4, as is illustrated inFIG. 2. The molding compound4may consist of or comprise a plastics material, e.g., epoxy or silicone.

In addition, the thickness of the molded body5may already be adapted to the thickness of the semiconductor chips2during production by a mold being placed onto the semiconductor chips2and the through-contacts3and the molding material being introduced into the interspaces. In this embodiment it is advantageous if the through-contact is flexible in terms of length or height in order to be able to adapt to semiconductor chips of different thicknesses during the molding process and embedding into the molded body. The through-contact may be configured such that it is elastically or plastically deformable.

After curing of the molding compound4, the arrangement in accordance withFIG. 3is obtained, wherein the semiconductor chips2and the through-contacts3are embedded into a molded body5. If the thickness of the molded body5is greater than the thickness of the semiconductor chips2, then after the curing of the molding compound4it is still necessary to remove the projecting molding compound4in order to obtain the arrangement in accordance withFIG. 3. In this case, a first side6of the semiconductor chips2and a first contact pad7of the through-contacts3are arranged on a first side of the molded body5and free of the molded body. A second side8of the semiconductor chips2lies on the carrier1. A second contact pad9of the through-contacts3is arranged on a second side of the molded body5and bears on the carrier1. The first and second sides are arranged on opposite sides of the molded body5. Side faces of the semiconductor chips2and side faces of the through-contacts3are embedded into the molded body5. On account of the cutouts50, the through-contacts3are anchored more strongly in the molded body5since a molded body5is arranged on a straight line between the first and second electrical contact pads7,9. A second electrical contact13may be provided on the second side8of the semiconductor chips2, which second electrical contact was applied one the second side8of the semiconductor chips before the mounting of the semiconductor chips2. Depending on the embodiment, the second electrical contact13may also be applied in a later method step.

Afterward, as illustrated inFIG. 4, a first electrical contact10is applied on the first sides6of the semiconductor chips2. Moreover, before applying the first contact10on the first sides6of the semiconductor chips, a metal/semiconductor contact may be applied on the first sides6of the semiconductor chips. This is advantageous if, during the removal of the projecting molding compound, semiconductor material was also removed from the sides6of the semiconductor chips.

In a further embodiment, the semiconductor chips2comprise first electrical contacts10on the first sides6already during the process of embedding into the molded body5, such that it is no longer necessary to apply the first electrical contacts10in the method step inFIG. 4.

In addition, a further first electrical contact11is applied on the first contact pad7of the through-contacts3. The first electrical contact10and the further first electrical contact11are configured, e.g., in the form of a metal layer. The further electrical contact11may also extend laterally beyond the through-contact3right onto the molded body5. The metal layer of the first and further first contacts10,11may be produced by a combination of deposition and patterning methods. Deposition methods such as vapor deposition, sputtering or electrode deposition in interaction with photolithographic patterning and dry etching or wet-chemical etching may be used in this case. Moreover, printing methods such as screen printing, ink jet printing or aerosol jet printing, if appropriate with a subsequent sintering step, may be used. Moreover, combinations of the methods described may also be used.

Afterward, the molded body5with the semiconductor chips2and the through-contacts3is detached from the carrier1and secured by the first side6and the first contact pad7, respectively, on a second carrier12, as illustrated inFIG. 5. The second carrier12may be configured in accordance with the first carrier1. The semiconductor chips2already comprise a second electrical contact13on the second side8or the second electrical contacts13are applied in an edge region of the second side8of the semiconductor chips2, which faces or is adjacent to a through-contact3. Furthermore, a second electrical layer14is applied on the second contact pad9of the through-contacts3and the molded body5and the second electrical contact13of the semiconductor chips2in such a way that in each case a second electrical contact13of a semiconductor chip2is electrically conductively connected to an adjacent through-contact3via the second electrically conductive layer14.

The second electrically conductive layer14may be produced by a combination of deposition and patterning methods. Deposition methods such as vapor deposition, sputtering or electrode deposition in interaction with photolithographic patterning and dry etching or wet-chemical etching may be used in this case. Moreover, printing methods such as screen printing, ink jet printing or aerosol jet printing, if appropriate with a subsequent sintering step, may be used. Moreover, combinations of the methods described may also be used.

Depending on the embodiment chosen, a conversion layer15may be applied on the second side8of the semiconductor chips2, which constitutes a radiation-emitting side of the semiconductor chips. In a further method step, the arrangement is cingulated in accordance withFIG. 6, the separating line being illustrated schematically in the form of dashed lines16. The singulation may be carried out by sawing, grinding, laser cutting or breaking. In addition, the second carrier12is removed.

FIG. 7shows, in a perspective illustration, an optoelectronic component16that was produced in accordance with the method inFIGS. 1 to 6.FIG. 7illustrates an underside of the semiconductor component after the removal of the second carrier12. The first electrical contact10of the semiconductor chip2is arranged on the underside. The molded body5laterally surrounds the semiconductor chip2. In addition, further first electrical contacts11of two through-contacts3are arranged on the underside. In the exemplary embodiment illustrated, two through-contacts3are provided for the semiconductor chip2and thus two further first electrical contacts11are also arranged on the underside of the component16. Depending on the embodiment chosen, the two further first electrical contacts11of the two through-contacts3may be combined by means of a further contact layer, applied on the underside of the molded body5, to form an electrical terminal.

FIG. 8shows the top side of the component16in a schematic perspective illustration. In the embodiment illustrated, the top side constitutes the side via which radiation is emitted or radiation is received in the configuration as a photosensor. In the exemplary embodiment illustrated, the semiconductor chip2comprises two second electrical contacts13which are electrically conductively connected to a respective through-contact3via corresponding second electrical layers14. Depending on the embodiment chosen, the two second electrical layers14of the two through-contacts3may also be configured in the form of a common second electrical layer14.

Depending on the embodiment chosen, the semiconductor chip2may also comprise only one second electrical contact13. In this embodiment, only one through-contact3is then provided as well. The conversion layer15is arranged on the top side, said conversion layer being laterally surrounded by the molded body5. Depending on the embodiment chosen, the conversion layer15may be dispensed with and an emission side or an incidence side of the optoelectronic semiconductor chip2may be arranged.

The through-contacts3are merely illustrated schematically inFIGS. 1 to 8. Possible embodiments of the through-contacts will be described in more specific detail with reference to the following figures.

FIG. 9shows a through-contact in the form of a folded strip17in a schematic illustration. The strip17comprises a first section18, which is arranged parallel to the top side of the molded body or of the component in the installed state. The first section18is connected to a second section20via a first side19. The second section20is arranged parallel to the first section18. The first intermediate section19may be arranged perpendicular to the first section18. The first intermediate section19may also be bent, folded or arranged at a defined angle of not equal to 90° with respect to the first section18. The second section20is connected to a third section22via a second intermediate section21. The second intermediate section21may be configured and arranged in accordance with the first intermediate section19. The third section20is arranged parallel to the first and second sections18,20. The folded strip17may be produced from a metal. The folded strip17may comprise further cutouts23. The further cutouts23may be configured in the form of holes, protuberances of the strip or cutouts to a certain percentage of the layer thickness of the strip. In a simple embodiment, the further cutout23is configured as a continuous hole in the strip17.

The first section18constitutes a first contact pad of the through-contact, which is arranged at the top side of the molded body. The third section22constitutes a second contact pad of the through-contact which is arranged at the underside of the molded body. The free spaces between the sections18,20,22constitute cutouts50.

FIG. 10shows a through-contact in the form of a bent strip24. The bent strip24comprises a first end region25and a second end region26, which are arranged parallel to one another, for example. The first end region25constitutes a first contact pad of the through-contact and is arranged at the top side of the molded body in the installed state. The second end region26constitutes a second contact pad of the through-contact and is arranged at the underside of the molded body in the installed state. Depending on the embodiment chosen, the bent strip24may comprise at least one or more further cutouts23. The further cutouts23may be indentations, protuberances or continuous holes. The bent strip may be produced from a metal. The free space between the first and second end regions25,26constitutes a cutout50.

FIG. 11shows a further embodiment of a through-contact in the form of electrically conductive wires27,28,29as conduction elements. The wires comprise, e.g., a circular cross section. The wires are mechanically connected to one another, in particular twisted together, in a connection region30, which is arranged in the center of the length of the wires. In this case, the wires are bent around one another, such that the wires are held together in a positively locking manner in the connection region. Depending on the embodiment chosen, it is also possible to provide only two wires or more than three wires twisted together as a through-contact. The first ends31of the wires27,28,29constitute a first contact pad of the through-contact. Second ends32of the wires27,28,29constitute a second contact pad of the through-contact. In the mounted state, the first ends31are arranged in the region of the top side of the molded body5. The second ends32of the wires27,28,29are arranged in the region of the underside of the molded body. The wires are produced, e.g., from metal or a metal alloy. The free space between the wires27,28,29constitutes a cutout50.

FIG. 12shows a further embodiment of a through-contact configured in the form of a spiral33. The spiral33comprises a first winding34. Moreover, the spiral33comprises a last winding35at the opposite end. The first winding34constitutes a first contact pad of the through-contact and is arranged in the region of the top side of the molded body5in the installed state. The last winding35constitutes a second contact pad of the through-contact and is arranged on the underside of the molded body5in the installed state. The spiral33is formed from a wire wound around a longitudinal axis. The free spaces between the windings of the spiral33constitute cutouts50.

FIG. 13shows a further embodiment of the through-contact configured in the form of a spiral33. In this application, however, the spiral33is arranged with a longitudinal axis38parallel to the top side and respectively to the underside of the molded body5. In this case, upper winding sections36form a first contact pad of the through-contact. Lower winding sections37arranged opposite the upper winding sections36form a second contact pad of the through-contact. In the installed state, the upper winding sections36are arranged at the top side of the molded body5. The lower winding sections37are arranged at the underside of the molded body5. The molded body5is depicted schematically inFIG. 13. The free spaces between the windings of the spiral33constitute cutouts50.

FIG. 14shows, in a schematic illustration, optoelectronic semiconductor chips2arranged in a grid on a carrier1. Alongside the semiconductor chips2in each case a through-contact in the form of a meandering strip39is arranged on the carrier1. The meandering strips39are configured in the form of a continuous strip51. Strips51are arranged between the series of semiconductor chips2. The strips51are formed from an electrically conductive material, in particular from a metal or a metal alloy. A meandering strip39comprises a first section40, which is connected to a second section via a first intermediate section41. The second section42transitions into a third section44via a second intermediate section43. The third section44is arranged parallel to the first and second sections40,42and is arranged between the first and second sections40,42in terms of the height position. The third section44transitions into a fourth section46via a third intermediate section45. The fourth section46is arranged between the second and third sections42,44. The fourth section46is connected to a fifth section48via a fourth intermediate section47. The fifth section48is arranged at the same height as the first section40. The first intermediate section41and the second intermediate section43are arranged parallel to one another. The fourth intermediate section47is arranged parallel to the first intermediate section41. The third intermediate section44is arranged between the second and fourth intermediate sections43,47. Moreover, the third intermediate section45proceeding from an end region of the third section44is led obliquely upward to an initial region of the fourth section46. The second section42constitutes a first contact pad of the through-contact. The fifth section48constitutes a second contact pad of the through-contact. With the aid of a strip51comprising a plurality of meandering strips39a plurality of semiconductor chips2of a series may simultaneously be embedded into the molded body and correspondingly electrically contacted with the meandering strips39during a processing process. After the embedding of the strips51into the molded body and the electrical contacting of the semiconductor chips2, which is carried out in accordance with the process inFIGS. 1 to 6, the strips51are subdivided into individual meandering strips39, with each strip51being subdivided at cutting lines60.

FIG. 15shows a schematic side view of a singulated meandering strip39in accordance withFIG. 14in a longitudinal direction. The free spaces between the sections42,46,45,44,48constitute cutouts50.

A semiconductor chip2and a meandering strip39fromFIG. 14are processed in each case to form a component16, as illustrated schematically inFIG. 16, in accordance with the method which was described with reference toFIGS. 1 to 6.FIG. 16shows a view in a transverse direction of the meandering strip39. In this case, a meandering strip39and a semiconductor chip2are embedded into a molded body5. The configuration of the through-contact in the form of a meandering strip enables cost-effective production, wherein the meandering strip39is anchored securely and reliably in the molded body5. Depending on the embodiment chosen, the meandering strip39may comprise further cutouts23. The further cutouts23may be configured in the form of protuberances, depressions or continuous holes. The meandering strip39is flexible, in particular elastically or plastically deformable, and may be adapted in terms of its height to semiconductor chips2of different thicknesses.

FIG. 17shows a through-contact in the form of a folded strip17in a schematic illustration. The strip17comprises a first section18, which is arranged parallel to the top side of the molded body or of the component in the installed state. The first section18is connected to a second section20via a first intermediate section19. The second section20is arranged parallel to the first section18. The first intermediate section19may be arranged perpendicular to the first section18. The first intermediate section19may also be bent, folded or arranged at a defined angle of not equal to 90° with respect to the first section18. In the embodiment illustrated, the folded strip comprises a Z-shape in cross section. The folded strip17may be produced from a metal. The folded strip17may comprise further cutouts23. The further cutouts23may be configured in the form of holes, protuberances of the strip or cutouts up to a certain percentage of the layer thickness of the strip. In a simple embodiment, the further cutout23is configured as a continuous hole in the strip17. The first section18constitutes a first contact pad of the through-contact, which is arranged at the top side of the molded body. The second section20constitutes a second contact pad of the through-contact which is arranged at the underside of the molded body. The free spaces between the sections18,19,20constitute cutouts50.

FIG. 18shows a further embodiment of a through-contact in the form of electrically conductive strips67,68,69as conduction elements. The strips comprise, e.g., a rectangular cross section. The strips are mechanically connected to one another, in particular twisted together, in a connection region30arranged in the center of the length of the strips. In this case, the strips are bent around one another, such that the strips are held together in a positively locking manner in the connection region. Depending on the embodiment chosen, it is also possible to provide only two strips or more than three strips twisted together as a through-contact. The first ends31of the strips67,68,69constitute a first contact pad of the through-contact. Second ends32of the strips67,68,69constitute a second contact pad of the through-contact. In the mounted state, the first ends31of the strips are arranged in the region of the top side of the molded body5. The second ends32of the strips67,68,69are arranged in the region of the underside of the molded body. The strips are produced, e.g., from metal or a metal alloy. The free spaces between the strips67,68,69constitute a cutout50.

FIG. 19shows a further embodiment of a through-contact which is configured in the form of a second spiral73. The second spiral73is formed from a strip. The second spiral73comprises a first winding34. Moreover, the spiral73comprises a last winding35at the opposite end. The first winding34constitutes a first contact pad of the through-contact and is arranged in the region of the top side of the molded body5in the installed state. The last winding35constitutes a second contact pad of the through-contact and is arranged on the underside of the molded body5in the installed state. The second spiral73is formed from a strip wound around a longitudinal axis. The free spaces between the windings of the second spiral73constitute cutouts50.

FIG. 20shows a further embodiment of the through-contact which is configured in the form of a second spiral73. In this application, however, the second spiral73is arranged with a longitudinal axis38parallel to the top side and respectively to the underside of the molded body5. In this case, upper winding sections36form a first contact pad of the through-contact. Lower winding sections37arranged opposite the upper winding sections36form a second contact pad of the through-contact. In the installed state, the upper winding sections36are arranged at the top side of the molded body5. The lower winding sections37are arranged at the underside of the molded body5. The molded body5is depicted schematically inFIG. 20. The free spaces between the windings of the spiral33constitute cutouts50.

FIG. 21shows two optoelectronic components16, which were produced in accordance with the method steps which were described above with reference toFIGS. 1 to 6. In this exemplary embodiment, a strip17folded in a Z-shape is provided as a through-contact. As explained above, the forms of through-contacts described with reference to the previous figures may also be used as the through-contact, in order to produce optoelectronic components comprising through-contacts.

The method described with reference toFIGS. 1 to 6may also be used for embedding the optoelectronic component and introducing at least two through-contacts, wherein the component comprises the first electrical contact10and the second electrical contact13on the top side, wherein the first electrical contact and the second electrical contact are led via two corresponding through-contacts in the molded body onto an underside.

FIG. 22shows, in a schematic arrangement, an optoelectronic component16comprising on an upper side a first and a second electrical contact10,13, which are spaced apart from one another and electrically insulated from one another. The two electrical contacts are used for operating the component16. The first electrical contact10is electrically conductively connected to a through-contact3via a second electrical layer14. The through-contact3is embedded into the molded body5and led as far as a lower side of the molded body5. A further first electrical contact11is arranged on the lower side of the molded body5, said further first electrical contact being electrically conductively connected to the through-contact3. The second electrical contact13is electrically conductively connected to a further through-contact3via a further second electrical layer14. The further through-contact3is embedded into the molded body5and led as far as a first side of the molded body5. A further first electrical contact11is arranged on the first side of the molded body5, said further first electrical contact being electrically conductively connected to the through-contact3. The through-contact3may be realized in one of the forms described in the previous examples. In particular, the through-contact can be configured in the form of a bent or folded strip or in the form of a spiral or in the form of connected conduction elements.

FIG. 23shows a view from below of the component16fromFIG. 22with the view encompassing the two further first electrical contacts11of the two through-contacts3.

Although the invention has been more specifically illustrated and described in detail by means of the preferred exemplary embodiment, nevertheless the invention is not restricted by the examples disclosed and other variations may be derived therefrom by the person skilled in the art, without departing from the scope of protection of the invention.