Optoelectronic component and method for the production thereof

Abstract

A method for producing an optoelectronic component includes creating a first layer of a polymer material. The method also includes applying crystals to a surface of the first layer. The method also includes creating a second layer of a polymer material on the surface of the first layer. The crystals can be between the first and second layers.

Claims

1. A method for producing an optoelectronic component, the method comprising: forming a first layer of a polymer material; applying crystals onto a surface of the first layer; and forming a second layer of a polymer material on the surface of the first layer, wherein the crystals have a concave shape, wherein the first layer and the second layer are formed with the same polymer material, wherein the crystals are applied before any curing of the material of the first layer, wherein the second layer is formed before any curing of the material of the first layer, wherein the first layer and the second layer have different thermal expansion coefficients to one another, wherein a majority of the crystals are enclosed locally by the material of the first layer and locally by the material of the second layer, and wherein a majority of the crystals locally directly adjoin the first layer and the second layer.

2. The method according to claim 1, wherein the crystals are scattered onto the surface of the first layer.

3. The method according to claim 1, wherein the crystals are applied without using a dispersion additive.

4. An optoelectronic component comprising: a first layer of a polymer material; a second layer of a polymer material that adjoins the first layer; and crystals arranged in a contact region between the first layer and the second layer, wherein a majority of the crystals are enclosed locally by the material of the first layer and locally by the material of the second layer, wherein a majority of the crystals locally directly adjoin the first layer and the second layer, and wherein the first layer and the second layer locally adjoin each other.

5. The optoelectronic component according to claim 4, wherein the crystals each have a concave shape.

6. The optoelectronic component according to claim 4, further comprising an optoelectronic semiconductor chip, wherein the first layer or the second layer directly adjoins the optoelectronic semiconductor chip.

7. The optoelectronic component according to claim 4, wherein the first layer or the second layer consists essentially of a silicone.

8. The optoelectronic component according to claim 4, wherein the first layer or the second layer consists essentially of polytetrafluoroethylene.

9. The optoelectronic component according to claim 4, wherein the crystals have an average size of less than 0.5 mm.

10. The optoelectronic component according to claim 9, wherein the crystals have an average size of less than 0.2 mm.

11. The optoelectronic component according to claim 4, wherein the crystals consist essentially of zinc oxide.

12. The optoelectronic component according to claim 4, wherein the crystals are configured as tetrapods.

13. The optoelectronic component according to claim 4, wherein optically reflective particles are embedded in the material of the first layer.

14. The optoelectronic component according to claim 4, wherein the second layer forms an optical lens of the optoelectronic component.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The properties, features and advantages of this invention as described above, and the way in which they are achieved, will become more clearly and readily comprehensible in conjunction with the following description of the exemplary embodiments, which will be explained in more detail in connection with the drawings. In schematic representations:

(2) FIG. 1 shows a perspective representation of a crystal;

(3) FIG. 2 shows a surface of a polymer layer with crystals partially sunk therein;

(4) FIG. 3 shows a sectional representation of a part of an optoelectronic component according to a first embodiment; and

(5) FIG. 4 shows a sectional representation of an optoelectronic component according to a second embodiment.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

(6) FIG. 1 shows a perspective representation of a crystal 100. The crystal 100 represented by way of example is a zinc oxide crystal in the form of a tetrapod. The crystal 100 could, however, also be replaced with a crystal consisting of a different material and/or be replaced with a different shape.

(7) The crystal 100 configured in the form of a tetrapod has a first branch 110, a second branch 120, a third branch 130 and a fourth branch 140. The first branch 110, the second branch 120, the third branch 130 and the fourth branch 140 extend from a common center 150 to the vertices of an imaginary tetrahedron.

(8) Each of the four branches 110, 120, 130, 140 has a branch length 115. The branch length 115 may, for example, lie in the range of between 10 m and 100 m. Each of the branches 110, 120, 130, 140 has an average branch diameter 116. The branch diameter 116 may, for example, lie between 1 m and 10 m. This leads to an overall dimension of the crystal 100 of less than 0.5 mm, preferably less than 0.2 mm. The crystal 100 may, however, also be configured to be smaller or larger.

(9) The crystal 100 configured in the form of a tetrapod has a concave shape. An imaginary concave envelope 160 may be placed around the first branch 110, the second branch 120, the third branch 130 and the fourth branch 140 of the crystal 100. If the crystal 100 consisting of zinc oxide is replaced with an alternative crystal, then the alternative crystal preferably also has a concave shape.

(10) FIG. 2 shows a plan view of a surface 210 of a polymer layer 200. The polymer layer 200 consists of a polymer material. For example, the polymer layer 200 may consist of a silicone. The polymer layer 200 may, for example, also consist of polytetrafluoroethylene (PTFE), a polyphthalamide (PPA), an epoxy-based thermoset, polyester or another polymer material. The material of the polymer layer 200 was applied in liquid form. The material of the polymer layer 200 is subsequently cured.

(11) A multiplicity of the crystals 100 represented in FIG. 1 were applied onto the surface 210 of the polymer layer 200. The crystals 100 on the surface 210 of the polymer layer 200 have partially sunk into the material of the polymer layer 200 on the surface 210 of the polymer layer 200. Some branches 110, 120, 130, 140 of the crystals 100 protrude at the surface 210 out of the material of the polymer layer 200. Other branches 110, 120, 130, 140 of the crystals 100 are arranged inside the polymer layer 200. In this way, the crystals 100 are anchored in the polymer layer 200.

(12) The crystals 100 were preferably applied onto the surface 210 of the polymer layer 200 before full curing of the material of the polymer layer 200. This facilitates partial sinking of the crystals 100 into the polymer layer 200.

(13) The crystals 100 were preferably scattered onto the surface 210 of the polymer layer 200. The scattering of the crystals 100 onto the surface 210 of the polymer layer 200 may be carried out without a dispersion additive.

(14) In a subsequent process step, a further layer of a polymer material may be applied onto the surface 210 of the polymer layer 200. The branches 110, 120, 130, 140, which protrude beyond the surface 210 of the polymer layer 200, of the crystals 100 arranged on the surface 210 of the polymer layer 200 are in this case embedded in the polymer material of the further layer and therefore anchored in the further layer. At the same time, the crystals 100 are partially embedded in the material of the polymer layer 200 and therefore anchored in the polymer layer 200. In this way, the crystals 100 lead to adhesion, achieved by anchoring or hooking, between the polymer layer 200 and the further layer of polymer material.

(15) Preferably, the further layer of polymer material is applied onto the surface 210 of the polymer layer 200 before the polymer material of the polymer layer 200 is fully cured. This processing may be referred to as wet-wet processing. The polymer layer 200 and the further layer of the polymer material may then be cured together, so that particularly effective adhesion is achieved between the polymer layer 200 and the further layer of polymer material, arranged on the surface 210 of the polymer layer 200.

(16) FIG. 3 shows a schematic sectional representation of a part of an optoelectronic component 300. The optoelectronic component 300 may, for example, be a light-emitting diode component.

(17) The optoelectronic component 300 has a housing 310. The housing 310 comprises a bottom 320 and a circumferential delimiting ring 330 arranged on an upper side of the bottom 320. The bottom 320 and/or the delimiting ring 330 of the housing 310 may consist of a ceramic material. For example, the bottom 320 and/or the delimiting ring 330 of the housing 310 may consist of AlN.

(18) In the region above the bottom 320 bounded laterally by the delimiting ring 330, the housing 310 of the optoelectronic component 300 has an internal space 340. In the region of the internal space 340, a first contact surface 321 and a second contact surface 322 are arranged on the upper side of the bottom 320. The first contact surface 321 and the second contact surface 322 respectively consist of an electrically conductive material.

(19) The optoelectronic component 300 furthermore comprises an optoelectronic semiconductor chip 400. The optoelectronic semiconductor chip 400 may, for example, be a light-emitting diode chip (LED chip). The optoelectronic semiconductor chip 400 is arranged above the first contact surface 321 in the internal space 340 of the housing 310 of the optoelectronic component 300. Provided between the first contact surface 321 and the optoelectronic semiconductor chip 400, there is a lower connecting layer 410. The lower connecting layer 410 may, for example, be configured to be electrically conductive. The lower connecting layer 410 may, for example, be formed by a solder connection.

(20) In the example of the optoelectronic component 300 as represented, a conversion layer 430, which is connected by means of an upper connecting layer 420 to the optoelectronic semiconductor chip 400, is arranged on an upper side of the optoelectronic semiconductor chip 400, on the opposite side from the bottom 320 of the housing 310. The conversion layer 430 may, for example, consist of a silicone. The conversion layer 430 may be used in order to convert a wavelength of electromagnetic radiation emitted by the optoelectronic semiconductor chip 400. To this end, wavelength-converting particles may be embedded in the converting layer 430. The upper connecting layer 420 may be omitted.

(21) Extending between the upper side of the optoelectronic semiconductor chip 400 and the second contact surface 322 on the bottom 320 of the housing 310, there is a bonding wire 323 which establishes an electrically conductive connection between the optoelectronic semiconductor chip 400 and the second contact surface 322.

(22) Arranged in a region, extending externally around the optoelectronic semiconductor chip 400, of the internal space 340 of the housing 310 of the optoelectronic component 300, there is a reflector layer 350. The reflector layer 350 is bounded by the delimiting ring 330 of the housing 310, the bottom 320 of the housing 310, and the optoelectronic semiconductor chip 400. An upper side 351, facing away from the bottom 320 of the housing 310, of the reflector layer 350 is approximately flush with an upper side of the conversion layer 430.

(23) The reflector layer 350 may consist of a silicone. Optically reflective particles 352 are embedded in the reflector layer 350. The particles 352 embedded in the material of the reflector layer 350 may, for example, consist of TiO.sub.2. The bonding wire 323 is embedded in the reflector layer 350, so that protection of the bonding wire 323 from mechanical damage is obtained.

(24) Arranged above the upper side 351 of the reflector layer 350 and above the conversion layer 430, there is an encapsulation layer 360 in the internal space 340 of the housing 310 of the optoelectronic component 300. The encapsulation layer 360 is used as mechanical protection for the reflector layer 350 and the conversion layer 430. The encapsulation layer 360 may consist of a silicone.

(25) A lower side 361 of the encapsulation layer 360 adjoins the upper side 351 of the reflector layer 350. A contact region 370 is therefore formed between the upper side 351 of the reflector layer 350 and the lower side 361 of the encapsulation layer 360. A multiplicity of crystals 100 are arranged in the contact region 370. Preferably, the crystals 100 are embedded partially in the reflector layer 350 and partially in the encapsulation layer 360. The crystals 100 arranged in the contact region 370 lead to adhesion, generated by anchoring, between the reflector layer 350 and the encapsulation layer 360, as explained with reference to FIG. 2. The crystals 100 arranged in the contact region 370 between the reflector layer 350 and the encapsulation layer 360 therefore improve the adhesion of the encapsulation layer 360 on the reflector layer 350 and prevent delamination between the reflector layer 350 and the encapsulation layer 360.

(26) The crystals 100 were preferably already applied onto the upper side 351 of the reflector layer 350 before the curing of the reflector layer 350. Subsequently, the encapsulation layer 360 was preferably already applied onto the upper side 351 of the reflector layer 350 before the curing of the reflector layer 350.

(27) Crystals 100 may also be arranged in the region between the conversion layer 430 and the encapsulation layer 360 and increase adhesion between the conversion layer 430 and the encapsulation layer 360.

(28) FIG. 4 shows a schematic sectional representation of an optoelectronic component 500 according to a second embodiment. The optoelectronic component 500 may, for example, be a light-emitting diode component.

(29) The optoelectronic component 500 has a housing 510 being only represented schematically in FIG. 4. The housing 510 comprises a bottom 520. A first section of the bottom 520 forms a first electrical contact surface 521. A second section of the bottom 520 forms a second electrical contact surface 522. The housing 510 of the optoelectronic component 500 furthermore comprises a delimiting ring 530, which is arranged on an upper side of the bottom 520 and circumferentially bounds an internal space 540 of the housing 510. The housing 510 of the optoelectronic component 500 is arranged on a carrier 580 being represented only schematically in FIG. 4.

(30) In the internal space 540 of the housing 510 of the optoelectronic component 500, an optoelectronic semiconductor chip 600 is arranged on the first contact surface 521 of the bottom 520. The optoelectronic semiconductor chip 600 may, for example, be an LED chip. The optoelectronic semiconductor chip 600 is electrically conductively connected to the second contact surface 522 by means of a bonding wire 523.

(31) The internal space 540 of the housing 510 of the optoelectronic component 500 is filled with an encapsulation layer 550, in which the optoelectronic semiconductor chip 600 and the bonding wire 523 are embedded. The encapsulation layer 550 is used for mechanical protection of the optoelectronic semiconductor chip 600 and of the bonding wire 523. The encapsulation layer 550 may, for example, consist of a silicone and was introduced in liquid form into the internal space 540 of the housing 510. An upper side 551 of the encapsulation layer 550 is approximately flush with an upper side of the delimiting ring 530 of the housing 510.

(32) A lens 560 is arranged on the upper side 551 of the encapsulation layer 550 of the optoelectronic component 500. The lens 560 is used as the optical lens and may, for example, be used for collimation of electromagnetic radiation emitted by the optoelectronic semiconductor chip 600. To this end, an outer side 562, facing away from the encapsulation layer 550, of the lens 560 is configured to be convex in the example represented.

(33) The lens 560 may, for example, consist of silicone and was applied in liquid form onto the upper side 551 of the encapsulation layer 550. A lower side 561 of the lens 560 faces toward the upper side 551 of the encapsulation layer 550. A contact region 570 is formed at the boundary between the upper side 551 of the encapsulation layer 550 and the lower side 561 of the lens 560. A multiplicity of crystals 100 which lead to adhesion, achieved by hooking or anchoring, between the encapsulation layer 550 and the lens 560, as explained with reference to FIG. 2, are arranged in the contact region 570. The branches 110, 120, 130, 140 of the crystals 100 arranged in the contact region 570 are embedded partially in the encapsulation layer 550 and partially in the lens 560. In this way, the crystals 100 hold the lens 560 on the encapsulation layer 550.

(34) Preferably, the crystals 100 were applied by scattering onto the upper side 551 of the encapsulation layer 550. Preferably, the crystals 100 were already applied onto the upper side 551 of the encapsulation layer 550 before full curing of the encapsulation layer 550. The lens 560 was subsequently applied onto the upper side 551 of the encapsulation layer 550. Preferably, the application of the lens 560 also already took place before full curing of the encapsulation layer 550. The encapsulation layer 550 and the lens 560 are subsequently cured together.

(35) The invention has been illustrated and described in detail with the aid of the preferred exemplary embodiments. Nevertheless, the invention is not restricted to the examples disclosed. Rather, other variants may be derived therefrom by the person skilled in the art without departing from the protective scope of the invention.