Optoelectronic semiconductor component

Abstract

An optoelectronic semiconductor component is provided, having a connection carrier (2), an optoelectronic semiconductor chip (1), which is arranged on a mounting face (22) of the connection carrier (2), and a radiation-transmissive body (3), which surrounds the semiconductor chip (1), wherein the radiation-transmissive body (3) contains a silicone, the radiation-transmissive body (3) has at least one side face (31) which extends at least in places at an angle β of <90° to the mounting face (22) and the side face (3) is produced by a singulation process.

Claims

1. A method of producing an optoelectronic semiconductor component, comprising the following steps: providing a connection carrier with a mounting face; attaching and electrically contacting an optoelectronic semiconductor chip to the mounting face; molding a radiation-transmissive body around the optoelectronic semiconductor chip; and sawing the radiation-transmissive body at an angle of <90° to the mounting face of the connection carrier in order at least in places to produce a side face of the radiation-transmissive body; wherein the side face extends at least in places at an angle of less than 90° to the mounting face of the connection carrier; and wherein the radiation-transmissive body surrounds the semiconductor chip in such a way that the radiation-transmissive body envelops outer faces of the optoelectronic semiconductor chip not facing the connection carrier in form-fitting manner and wherein the optoelectronic semiconductor chip emits or receives light during its operation and the radiation-transmissive body is transmissive to the light emitted or received by the optoelectronic semiconductor chip.

2. The method according to claim 1, further comprising a step of sawing the radiation-transmissive body entirely at an angle of <90° to the mounting face of the connection carrier in order to produce four side faces of the radiation-transmissive body, such that the radiation-transmissive body takes the form of a truncated pyramid.

3. The method according to claim 1, wherein a planarisation layer is sprayed onto the side face of the radiation-transmissive body that is produced by sawing.

4. The method according to claim 1, further comprising a step of arranging at least one layer between the radiation-transmission body and the connection carrier, wherein the layer increases the adhesion between the radiation-transmissive body and the connection carrier.

5. The method according to claim 4, wherein the radiation-transmissive body contains a silicone and the layer comprises a silicone foil.

6. The method according to claim 1, wherein the connection carrier forms part of the casting.

7. The method according to claim 1, wherein the connection carrier comprises a base member made of a ceramic material, and wherein the base member has a thickness of to at least 100 μm and at most 400 μm.

8. The method according to claim 6, wherein the connection carrier comprises a base member, wherein the radiation-transmissive body directly adjoins the mounting face of the connection carrier.

9. The method according to claim 1, wherein the connection carrier has saw markings on the mounting face that define the position of the radiation-transmissive body relative to the semiconductor chip.

10. The method according to claim 1, wherein different shaped saw blades are used.

11. The method according to claim 1, wherein material of the radiation-transmissive body is torn out during sawing forming singulation traces in the radiation-transmissive body.

12. The method according to claim 11, wherein the singulation traces comprise indentations in the radiation-transmissive body.

13. The method according to claim 1, wherein four side faces of the radiation-transmissive body are produced by sawing the radiation-transmissive body, wherein each of the four side faces extends completely at an angle of less than 90° to the mounting face, such that the radiation-transmissive body takes the form of a truncated pyramid, wherein each of the four side faces is produced in its entirety by sawing the radiation-transmissive body, and wherein the radiation-transmissive body comprises at least one side face, which extends at least in places at an angle of between 60° and 70° to the mounting face.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings:

(2) The optoelectronic semiconductor component described herein is explained in greater detail below with reference to exemplary embodiments and the associated figures:

(3) FIG. 1A is a schematic sectional representation of an optoelectronic semiconductor component described herein according to a first exemplary embodiment.

(4) FIG. 1B shows an enlarged portion of an optoelectronic semiconductor component described herein in a second exemplary embodiment.

(5) FIG. 1C schematically plots outcoupling efficiency as a function of surface scattering for one exemplary embodiment of an optoelectronic semiconductor component described herein.

(6) FIG. 2 is a schematic perspective representation of an optoelectronic semiconductor component described herein according to a further exemplary embodiment.

(7) FIG. 3 shows simulations of outcoupling efficiency as a function of slope angle for one exemplary embodiment of an optoelectronic semiconductor component described herein.

(8) FIG. 4 shows simulations of outcoupling efficiency as a function of the thickness of the base member of the connection carrier for one exemplary embodiment of an optoelectronic semiconductor component described herein.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

(9) Identical, similar or identically acting elements are provided with the same reference numerals in the Figures. The Figures and the size ratios of the elements illustrated in the Figures relative to one another are not to be regarded as being to scale. Rather, individual elements may be illustrated on an exaggeratedly large scale for greater ease of depiction and/or better comprehension.

(10) FIG. 1A is a schematic sectional representation of an optoelectronic semiconductor component described herein according to a first exemplary embodiment. The semiconductor component comprises an optoelectronic semiconductor chip 1. In this case, the optoelectronic semiconductor chip 1 is a light-emitting diode chip, of thin-film construction. Light-emitting diode chips of thin-film construction are described for example in documents WO 02/13281 A1 and EP 0 905 797 A2, the disclosure content of which is hereby expressly included by reference with regard to the thin-film construction of light-emitting diode chips.

(11) The optoelectronic semiconductor chip 1 is applied to the mounting face 22 of a connection carrier 2. The connection carrier 2 further comprises a base member 20, which is here made of a ceramic material. Electrical connection points 21 are applied to the bottom, opposite the mounting face 22, of the base member 20 of the connection carrier 2, by way of which connection points 22 the optoelectronic semiconductor component is surface-mountable. The optoelectronic semiconductor chip 1 is encapsulated in a radiation-transmissive body 3.

(12) The radiation-transmissive body 3 envelops the optoelectronic semiconductor chip 1 in form-fitting manner. The radiation-transmissive body 3 here consists of a silicone. The radiation-transmissive body 3 directly adjoins the mounting face 22 of the connection carrier 2. The radiation-transmissive body 3 comprises side faces 30. The side faces 30 extend in planar manner, apart from singulation traces 31, which are shown exaggeratedly large in FIG. 1A to make them more visible. The side faces 30 form an angle β of <90° with the mounting face 22 of the connection carrier 2, that is to say the slope angle α, which is obtained from the angle of the side face 30 with the surface normal 23 to the mounting face 22, is >0°.

(13) The side faces 30 are produced by a sawing process. The singulation traces 31 comprise saw grooves or other defects such as for example indentations, which arise when material is “torn out” of the radiation-transmissive body 3 during sawing.

(14) The optoelectronic semiconductor chip 1 may be arranged centred relative to the radiation-transmissive body 3 and to the connection carrier 2, that is to say the optical axis 4 through the centre of the radiation exit face 10 of the optoelectronic semiconductor chip 1 then constitutes an axis of symmetry of the optoelectronic semiconductor component. The above-described centring is desirable above all with regard to particularly symmetrical emission. However, non-centred configurations are also possible.

(15) The optoelectronic semiconductor chip 1 is adjusted relative to the radiation-transmissive body 3 during the singulation process for example by means of adjustment marks, not shown, on the mounting surface 22 of the connection carrier 2.

(16) FIG. 1B shows an enlarged portion of an optoelectronic semiconductor component described herein according to a second exemplary embodiment. Unlike the exemplary embodiment described in conjunction with FIG. 1A, in this exemplary embodiment a planarisation layer 5 has been arranged on the side face 30 produced by a singulation process. The planarisation layer 5 has in this case been sprayed onto the side face 30. The planarisation layer 5 here consists of silicone. The planarisation layer 5 evens out the unevennesses of the side face 30 produced by the singulation traces 31.

(17) To this end, FIG. 1C shows a schematic plot of outcoupling efficiency in the case of a slope angle α of 25° as a function of surface scattering at the radiation-transmissive body 3. It is assumed that the radiation-transmissive body consists of silicone and has a height H of 400 μm. The base member 20 of the connection carrier 2 consists of a ceramic material and has a thickness D of 200 μm. It is apparent from FIG. 1C that outcoupling efficiency falls with increasing surface scattering at side faces 30 of the radiation-transmissive body 3. Unevennesses on the side faces 30 of the radiation-transmissive body increase surface scattering. The planarisation layer 5 therefore proves particularly advantageous with regard to outcoupling efficiency.

(18) A further exemplary embodiment of an optoelectronic semiconductor component described herein is explained in greater detail in conjunction with the schematic perspective representation of FIG. 2.

(19) As is clear from FIG. 2, the radiation-transmissive body 3 takes the form of a truncated pyramid, which comprises four sloping side faces 30, which are produced by means of a singulation process, in the present case sawing.

(20) The connection carrier 2 comprises a base member 20 of a ceramic material, which has a thickness D of preferably at least 0.2 mm and at most 0.5 mm, for example 0.4 mm. The radiation-transmissive body 3 has a height H preferably of between 0.55 mm and 0.25 mm, for example of 0.35 mm. The sum of the thickness of the main body 20 and height H of the radiation-transmissive body 3 preferably amounts to between 0.7 mm and 0.8 mm, for example 0.75 mm.

(21) The slope angle α amounts for example to 25°. The area of the top face 32 of the radiation-transmissive body preferably amounts to between 2.0 and 2.5 mm.sup.2, for example 2.3 mm.sup.2.

(22) The connection carrier 2 has a base area, for example, of 2.04 mm×1.64 mm.

(23) The optoelectronic semiconductor chip 1 comprises a radiation exit face 10, which may have an area of 500 μm.sup.2 to 1.5 mm.sup.2, for example 1.0 mm.sup.2. The radiation exit face 10 may be square.

(24) FIG. 3 shows simulation results for the outcoupling efficiency of an optoelectronic semiconductor component, as shown in conjunction with FIG. 2.

(25) As may be inferred from FIG. 3, outcoupling efficiency reaches its maximum for a slope angle α=25°. Outcoupling efficiency is increased by around 13% over a structure with a slope angle=0°. The maximum around the slope angle of 25° is relatively flat, resulting in a wide angular tolerance range of +/−5° for optimum outcoupling, so providing a wide process window for mass production of the optoelectronic semiconductor component. The preferred angular range for the slope angle is therefore between 20° and 30°, preferably 25°. This ideal angle is however also dependent on the size of the base area of the connection carrier 2 and may therefore differ for larger structures. It is important for the radiation-transmissive body to comprise at least one side face 30 which extends at least in places at an angle β of <90° to the mounting face 22.

(26) FIG. 4 shows simulation results for the outcoupling efficiency of an optoelectronic semiconductor component, as shown in conjunction with FIG. 2. Outcoupling efficiency is here plotted against the thickness D of the main body 20 of the connection carrier 2. The height H of the radiation-transmissive body 3 is selected in each case such that the sum of thickness D and height H is 750 μm. As may be inferred from the figure, the outcoupling efficiency is greater, the thinner is the connection carrier. A thickness of the main body D of at most 250 μm is therefore preferred.

(27) The description made with reference to exemplary embodiments does not restrict the invention to these embodiments. Rather, the invention encompasses any novel feature and any combination of features, including in particular any combination of features in the claims, even if this feature or this combination is not itself explicitly indicated in the claims or exemplary embodiments.

(28) Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.