WO2024088869A1

WO2024088869A1 - Optoelectronic component

Info

Publication number: WO2024088869A1
Application number: PCT/EP2023/079118
Authority: WO
Inventors: Marco Antretter; Bilal SAIF; Anton Vogl
Original assignee: Ams-Osram International Gmbh
Priority date: 2022-10-25
Filing date: 2023-10-19
Publication date: 2024-05-02

Abstract

The invention relates to an optoelectronic component comprising an optoelectronic semiconductor chip and a driver circuit. The optoelectronic semiconductor chip comprises a pixel array with a plurality of pixels. The optoelectronic semiconductor chip is arranged on top of the driver circuit. The optoelectronic component further comprises a first positive electrode and a first negative electrode. The optoelectronic semiconductor chip is arranged in such a way relative to the first positive electrode and the first negative electrode that a material of the optoelectronic semiconductor chip acts as a dielectric of a first capacitor formed by the first positive electrode and the first negative electrode. The driver circuit comprises a read-out circuit to read out a first capacity of the first capacitor.

Description

OPTOELECTRONIC COMPONENT

DESCRIPTION

The present invention relates to an optoelectronic component , an illumination device , a method of production of an optoelectronic component and a method of operation of an optoelectronic component .

This patent application claims the priority of German patent application DE 10 2022 128 243 . 0 filed on 25 October 2022 , the disclosure content of which is hereby incorporated by reference .

Optoelectronic components may comprise an optoelectronic semiconductor chip and a driver circuit , wherein the optoelectronic semiconductor chip comprises a pixel array with a plurality of pixels . The pixel array may include light emitting pixels as well as photodiodes . Having accurate information regarding a temperature of the optoelectronic semiconductor chip is useful for many applications of such an optoelectronic component . A temperature sensor arranged within the driver circuit may be used to measure such a temperature . However, there are applications for which the accuracy of such a temperature sensor is insuf ficient . Placing temperature sensors directly at the pixels is challenging, as a pixel spacing may be in the range of 10 to 60 micrometers and placing temperature sensors in between is impractical .

An obj ect of the present invention is to provide an optoelectronic component including a possibility for a more accurate temperature measurement . Another obj ect of the present invention is to provide an illumination device with such an optoelectronic component , a method of production of such an optoelectronic component and a method of operation of such an optoelectronic component . These obj ects are solved by means of the subj ect matter of the independent patent claims . Further advantageous embodiments are indicated in the dependent claims .

According to a first aspect of the invention, an optoelectronic component comprises an optoelectronic semiconductor chip and a driver circuit . The optoelectronic semiconductor chip comprises a pixel array with a plurality of pixels . The optoelectronic semiconductor chip is arranged on top of the driver circuit . The optoelectronic component further comprises a first positive electrode and a first negative electrode . The optoelectronic semiconductor chip is arranged in such a way relative to the first positive electrode and the first negative electrode that a material of the optoelectronic semiconductor chip acts as a dielectric of a first capacitor formed by the first positive electrode and the first negative electrode . The driver circuit comprises a read-out circuit to read out a first capacity of the first capacitor .

Changes in the temperature of the optoelectronic semiconductor chip may lead to a change of a dielectric constant of the material of the optoelectronic semiconductor chip . Reading out the first capacity enables to assign a change in the first capacity to a temperature change of the material of the optoelectronic semiconductor chip . The driver circuit may be equipped to output a value related to the first capacity, either as a digital value or as an analog value . Using this approach may increase the accuracy of a temperature measurement of the optoelectronic semiconductor chip .

The optoelectronic semiconductor chip may be arranged directly on top of the driver circuit without any intermediate elements . Furthermore , only intermediate elements explained in the following may be arranged between the driver circuit and the optoelectronic semiconductor chip . Therefore , the driver circuit may be equipped with contact areas , particularly with metallic contact areas , capable of connecting contact areas of the optoelectronic semiconductor chip . According to a second aspect of the invention, an illumination device comprises a housing and the optoelectronic component , wherein the plurality of pixels comprises a plurality of independent light emitting diodes . Particularly for light emitting diodes accurate temperature measurements are useful .

According to a third aspect of the invention, a method of producing the optoelectronic component includes the following steps :

Providing the optoelectronic semiconductor chip and the driver circuit ;

Forming of the first positive electrode and the first negative electrode in such a way relative to the optoelectronic semiconductor chip that a material of the optoelectronic semiconductor chip acts as a dielectric of the first capacitor formed by the first positive electrode and the first negative electrode ;

Arranging the optoelectronic semiconductor chip on top of the driver circuit .

The first positive electrode and the first negative electrode may be formed at the optoelectronic semiconductor chip or at the driver circuit or at both .

According to a fourth aspect of the invention, in a method of operating the optoelectronic component a temperature of the pixel array is measured by an evaluation of the first capacity of the first capacitor .

In one embodiment of the optoelectronic component , the readout circuit is equipped to calculate a temperature from the read-out first capacity and to output a temperature value .

The driver circuit may be equipped to output the temperature value , either as a digital value or as an analog value .

In one embodiment the optoelectronic component comprises a further first positive electrode and a further first negative electrode . Particularly, the optoelectronic component com- prises several further first positive electrodes and several further first negative electrodes . Therefore , the optoelectronic component comprises several first positive electrodes and several first negative electrodes . The optoelectronic semiconductor chip is arranged in such a way relative to the further first electrodes that a material of the optoelectronic semiconductor chip acts as a dielectric of a further first capacitor formed by the further first electrodes , and wherein the driver circuit comprises a read-out circuit to read out a further first capacity of the further first capacitor . Particularly, any pair of first electrodes , also referred to as a first positive electrode and a first negative electrode , forms a first capacitor with the material of the optoelectronic semiconductor chip acting as a dielectric .

In the operating method, a temperature of the pixel array may be measured by an evaluation of the further first capacity of the further first capacitor .

In one embodiment the optoelectronic component comprises a second positive electrode and a second negative electrode . The optoelectronic semiconductor chip is arranged in such a way relative to the second positive electrode and the second negative electrode that a material of the optoelectronic semiconductor chip acts as a dielectric of a second capacitor formed by the second positive electrode and the second negative electrode . The driver circuit comprises a read-out circuit to read out a second capacity of the second capacitor .

Changes in the temperature of the optoelectronic semiconductor chip may lead to a change of a dielectric constant of the material of the optoelectronic semiconductor chip . Reading out the second capacity enables to assign a change in the second capacity to a temperature change of the material of the optoelectronic semiconductor chip . The driver circuit may be equipped to output a value related to the second capacity, either as a digital value or as an analog value . Using this approach may increase the accuracy of a temperature measurement of the optoelectronic semiconductor chip .

In the operating method, a temperature of the pixel array may be measured by an evaluation of the second capacity of the second capacitor .

In one embodiment of the optoelectronic component , the readout circuit is equipped to calculate a temperature from the read-out second capacity and to output a temperature value . The driver circuit may be equipped to output the temperature value , either as a digital value or as an analog value .

In one embodiment the optoelectronic component comprises a further second positive electrode and a further second negative electrode . Particularly, the optoelectronic component comprises several further second positive electrodes and several further second negative electrodes . Therefore , the optoelectronic component comprises several second positive electrodes and several second negative electrodes . The optoelectronic semiconductor chip is arranged in such a way relative to the further second electrodes that a material of the optoelectronic semiconductor chip acts as a dielectric of a further second capacitor formed by the further second electrodes . The driver circuit comprises a read-out circuit to read out a further second capacity of the further second capacitor . Particularly, any pair of second electrodes , also referred to as a second positive electrode and a second negative electrode , forms a second capacitor with the material of the optoelectronic semiconductor chip acting as a dielectric .

In the operating method, a temperature of the pixel array may be measured by an evaluation of the further second capacity of the further second capacitor .

In one embodiment of the optoelectronic component the optoelectronic semiconductor chip has a first extension direction and a second extension direction . The first capacitor is ar- ranged in the first extension direction and the second capacitor is arranged in the second extension direction . Should more than one first capacitor be present , all first capacitors may be arranged in the first extension direction . Should more than one second capacitor be present , all second capacitors may be arranged in the second extension direction .

In one embodiment of the optoelectronic component the driver circuit is equipped to evaluate at least two capacities and to spatially locate an area of the pixel array with increased temperature . The two capacities may be the capacities of two first capacitors or of a first capacitor and a second capacitor . Particularly, more than two capacities may be evaluated . In this case , a higher number of evaluated capacities may increase an accuracy of a location of the area of the pixel array with increased temperature .

In one embodiment the optoelectronic component further comprises a shielding to minimi ze external influence on the first capacitor and/or the second capacitor .

In one embodiment of the optoelectronic component the first electrodes and/or the second electrodes are at least partially arranged within the optoelectronic semiconductor chip . Particularly, the first electrodes and/or the second electrodes may be completely arranged within the optoelectronic semiconductor chip . This allows for precise temperature measurements .

In one embodiment of the optoelectronic component the first electrodes and/or the second electrodes are at least partially arranged at side surfaces of the optoelectronic semiconductor chip . This allows for an easy manufacturing .

In one embodiment of the optoelectronic component the first electrodes and/or the second electrodes are at least partially arranged on and/or within the driver circuit . In one embodiment of the optoelectronic component the first electrodes and/or the second electrodes comprise a metal . This allows for an easy manufacturing process . The metal may be arranged during a process of providing contact areas of the optoelectronic semiconductor chip and/or the driver circuit .

In one embodiment of the optoelectronic component the driver circuit is a CMOS .

In one embodiment of the optoelectronic component the driver circuit further comprises a temperature sensor . The temperature sensor may be used to calibrate the temperature measured using the first capacitor and/or the second capacitor .

In one embodiment of the optoelectronic component the driver circuit is equipped to initiali ze a measurement by reading out the temperature sensor and the first capacity and/or the second capacity and further equipped to assign changes in the first capacity and/or the second capacity to a temperature change . This may particularly also be part of the method of operating the optoelectronic component . This may be utili zed in a way that the reading out of the temperature sensor is made during an initiali zation directly after switching the optoelectronic component on . At that time , it may be assumed that the temperature sensor and the material of the optoelectronic semiconductor material have a uni form temperature .

In one embodiment of the optoelectronic component the plurality of pixels comprises a plurality of independent light emitting diodes .

In one embodiment of the method of operating the optoelectronic component the temperature is compared to a threshold temperature . Operating parameters of the pixel array are changed when the temperature exceeds the threshold temperature . This may lead to a ( at least partially executed) switch-of f of the pixel array . I f a temperature increase may be localized according to the methods and means explained above, areas with increased temperature may be operated in a way that a power consumption in these areas is decreased to also decrease the temperature there. In other words, the pixel array may be dimmed in these areas.

The properties, features and advantages of the present invention described above, as well as the manner in which they are achieved, become clearer and more understandable in connection with the following description of the embodiment examples, which are explained in more detail in connection with the drawings. In each case, the following examples show in a schematic representation

Fig. 1 an isometric view of an embodiment of an optoelectronic component;

Fig. 2 a top view of the optoelectronic component of Fig. 1;

Fig. 3 a top view of another embodiment of an optoelectronic component;

Fig. 4 a top view of another embodiment of an optoelectronic component;

Fig. 5 a top view of another embodiment of an optoelectronic component;

Fig. 6 a top view of another embodiment of an optoelectronic component;

Fig. 7 a cross section of the embodiment of Fig. 3;

Fig. 8 a cross section of another embodiment of an optoelectronic component; Fig. 9 a cross section of another embodiment of an optoelectronic component;

Fig. 10 a cross section of another embodiment of an optoelectronic component;

Fig. 11 a cross section of another embodiment of an optoelectronic component;

Fig. 12 a top view of another embodiment of an optoelectronic component;

Fig. 13 a top view of another embodiment of an optoelectronic component;

Fig. 14 a top view of another embodiment of an optoelectronic component;

Fig. 15 a cross section of the embodiment of Fig. 14;

Fig. 16 a top view of another embodiment of an optoelectronic component;

Fig. 17 a top view of another embodiment of an optoelectronic component; and

Fig. 18 an illumination device.

Fig. 1 shows an isometric view of an embodiment of an optoelectronic component 100. The optoelectronic component 100 comprises an optoelectronic semiconductor chip 110 and a driver circuit 150. The optoelectronic semiconductor chip 110 comprises a pixel array 111 with a plurality of pixels 112.

To improve the clarity of Fig. 1, only some of the pixels 112 are marked with a reference sign. Exemplarily, the pixel array 111 comprises a pixel layout with 40 pixels 112 in four rows and ten columns. However, the number of pixels 112 may be several orders of magnitude higher, for example in the range of 10 . 000 to 100 . 000 pixels 112 . The optoelectronic semiconductor chip 110 is arranged on top of the driver circuit 150 . There may be an interconnect between the driver circuit 150 and the optoelectronic semiconductor chip 110 . The interconnect may be part of the driver circuit 150 . Particularly, the driver circuit 150 and the optoelectronic semiconductor chip 110 may be in direct contact without any intermediate elements . Furthermore , only intermediate elements explained in the following may be arranged between the driver circuit 150 and the optoelectronic semiconductor chip 110 . The optoelectronic component 100 further comprises a first positive electrode 121 and a first negative electrode 122 . The optoelectronic semiconductor chip 110 is arranged in such a way relative to the first positive electrode 121 and the first negative electrode 122 that a material 113 of the optoelectronic semiconductor chip 110 acts as a dielectric of a first capacitor 131 formed by the first positive electrode 121 and the first negative electrode 122 . The driver circuit 150 comprises a read-out circuit 151 to read out a first capacity of the first capacitor 131 . In the embodiment of Fig . 1 , the first positive electrode 121 and the first negative electrode 122 are arranged at side surfaces 114 of the optoelectronic semiconductor chip 110 . However, the first positive electrode 121 and the first negative electrode 122 may also be part of the optoelectronic semiconductor chip 110 and particularly also comprise the material 113 of the semiconductor chip 110 .

Changes in the temperature of the optoelectronic semiconductor chip 110 may lead to a change of a dielectric constant of the material 113 . The relative dielectric constant for silicon dioxide increases from 2 . 90 to 3 . 25 when the temperature is increased from 22 degrees Celsius to 88 degrees Celsius . This change in the relative dielectric constant can be used to obtain a temperature . The dependency of relative dielectric constant and temperature may be a direct proportionality . However, also material with an indirect proportionality of relative dielectric constant and temperature may be used . Barium titanate is an example for a material with an indirect proportionality . During a temperature increase from 25 degrees Celsius to 95 degrees Celsius the relative dielectric constant of Barium titanate decreases from 1100 to 175 . Reading out the first capacity enables to assign a change in the first capacity to a temperature change of the material 113 . The driver circuit 151 may be equipped to output a value related to the first capacity, either as a digital value or as an analog value . Using this approach may increase the accuracy of a temperature measurement of the optoelectronic semiconductor chip 110 .

The driver circuit 150 may be equipped with contact areas , particularly with metallic contact areas , capable of connecting contact areas of the optoelectronic semiconductor chip 110 . The driver circuit 150 also may comprise a power supply circuit 152 to control a current supply for the pixels 112 . The driver circuit 150 may further comprise a temperature sensor 153 . Furthermore , the driver circuit 150 may be designed as a CMOS .

A method of operating the optoelectronic component 100 of Fig . 1 includes that a temperature of the pixel array 111 is measured by an evaluation of the first capacity of the first capacitor 131 . This may be performed by the read-out circuit 151 of the driver circuit 150 .

The optoelectronic component 100 may be produced by a method including the following steps . The optoelectronic semiconductor chip 110 and the driver circuit 150 are provided . The first positive electrode 121 and the first negative electrode 122 are formed in such a way relative to the optoelectronic semiconductor chip 110 that a material 113 of the optoelectronic semiconductor chip 110 acts as a dielectric of a first capacitor 131 formed by the first positive electrode 121 and the first negative electrode 122 . The optoelectronic semiconductor chip 110 is arranged on top of the driver circuit 150 . In one embodiment the read-out circuit 150 is equipped to calculate a temperature from the read-out first capacity and to output a temperature value .

Fig . 2 shows a top view of the optoelectronic component 100 of Fig . 1 . An electric connection of the first capacitor 131 to the driver circuit 150 may be formed by bond wires (not shown) . However, also other forms of contact formation are possible . The optoelectronic semiconductor chip 110 may have a first extension direction 115 and a second extension direction 116 . The first capacitor 131 is arranged in the first extension direction 115 . That may mean that an electric field of the first capacitor 131 is oriented in the first direction 115 .

In one embodiment the plurality of pixels 112 comprises a plurality of independent light emitting diodes . However, the pixels 112 may also comprise photodiodes or other optoelectronic diodes .

Fig . 3 shows a top view of another embodiment of an optoelectronic component 100 , which corresponds to the embodiment of Fig . 1 and 2 as far as no di f ferences are mentioned in the following . The first capacitor 131 formed by the first positive electrode 121 and the first negative electrode 122 is embedded within the material 113 . Thusly, the first positive electrode 121 and the first negative electrode 122 are not arranged on side surfaces of the semiconductor chip .

Fig . 4 shows a top view of another embodiment of an optoelectronic component 100 , which corresponds to the embodiment of Fig . 1 and 2 as far as no di f ferences are mentioned in the following . The optoelectronic component 100 comprises further first positive electrodes 123 and further first negative electrodes 124 . The optoelectronic semiconductor chip 110 is arranged in such a way relative to the further first electrodes 123 , 124 that the material 113 of the optoelectronic semiconductor chip 110 acts as a dielectric of further first capacitors 132 formed by the further first electrodes 123 , 124 . Each pair of one further first positive electrode 123 and one further first negative electrode forms one further first capacitor 132 . The driver circuit 150 comprises a readout circuit to read out a further first capacity of the further first capacitors 132 . Exemplarily, three further first capacitors 132 are shown in Fig . 4 . However, the number of further first capacitors 132 may vary and it is also possible to implement for example one further first capacitor 132 or more further first capacitors 132 , for example up to nine further first capacitors 132 . The optoelectronic semiconductor chip 110 may have a first extension direction 115 and a second extension direction 116 . The first capacitors 131 , 132 are arranged in the first extension direction 115 . That may mean that an electric field of the first capacitors 131 , 132 is oriented in the first direction 115 . Regarding the second extension direction 116 , the first capacitors 131 , 132 are arranged side by side .

Using the approach shown in Fig . 4 allows for a spatial resolution of a temperature measurement . Should only parts of the optoelectronic semiconductor chip 110 heat up or should the heating be nonuni form, the relative dielectric constant changes di f ferently for di f ferent first capacitors 131 , 132 . Therefore , relative to the second extension direction 116 , a heat map may be provided by the read-out of the first capacitors 131 , 132 .

The general approach of the optoelectronic component 100 component of Fig . 4 may also be implemented in an optoelectronic component 100 with first electrodes 121 , 122 , 123 , 124 embedded within the material 113 similar to the embodiment of Fig . 3 .

Fig . 5 shows a top view of another embodiment of an optoelectronic component 100 , which corresponds to the embodiment of Fig . 4 as far as no di f ferences are mentioned in the following . The optoelectronic component 100 further comprises a second positive electrode 125 and a second negative electrode 126 . The optoelectronic semiconductor chip 110 is arranged in such a way relative to the second positive electrode 125 and the second negative electrode 126 that the material 113 of the optoelectronic semiconductor chip 110 acts as a dielectric of a second capacitor 133 formed by the second positive electrode 125 and the second negative electrode 126 . The driver circuit 150 comprises a read-out circuit 151 to read out a second capacity of the second capacitor 133 . The second capacitor 133 is oriented perpendicular to the first capacitors 131 , 132 . Particularly, the second capacitor 133 is arranged in the second extension direction 116 . That may mean that an electric field of the second capacitor 133 is oriented in the second direction 116 . The read-out circuit 151 may be equipped to calculate a temperature from the read-out second capacity and to output a temperature value .

The embodiment of the optoelectronic component 100 in Fig . 5 comprises optionally a further second positive electrode 127 and a further second negative electrode 128 . The optoelectronic semiconductor chip 110 is arranged in such a way relative to the further second electrodes 127 , 128 that the material 113 of the optoelectronic semiconductor chip 110 acts as a dielectric of a further second capacitor 134 formed by the further second electrodes 127 , 128 . The driver circuit 150 comprises a read-out circuit 151 to read out a further second capacity of the further second capacitor 134 . More second capacitors 134 with additional further second electrodes 127 , 128 may also be present , despite not shown in Fig . 5 . The further second capacitor 134 is also oriented perpendicular to the first capacitors 131 , 132 . Particularly, the further second capacitor 134 is arranged in the second extension direction 116 . That may mean that an electric field of the further second capacitor 134 is oriented in the second direction 116 . Regarding the second extension direction 116 , the second capacitors 133 , 134 are arranged side by side . Using the approach shown in Fig. 5 allows for an enhanced spatial resolution of a temperature measurement. Should only parts of the optoelectronic semiconductor chip 110 heat up or should the heating be nonuniform, the relative dielectric constant changes differently for different first capacitors 131, 132 as well as for different second capacitors 133, 134. Therefore, relative to the first extension direction 115 as well as the second extension direction 116, a heat map may be provided by the read-out of the first capacitors 131, 132 and the second capacitors 133, 134.

Fig. 6 shows a top view of another embodiment of an optoelectronic component 100, which corresponds to the embodiment of Fig. 5 as far as no differences are mentioned in the following. Particularly the electrodes 121, 122, 123, 124, 125, 126, 127, 128 and therefore also the capacitors 131, 132, 133, 134 are arranged similarly relative to each other with respect to Fig. 5. However, the electrodes 121, 122, 123, 124, 125, 126, 127, 128 and therefore also the capacitors 131, 132, 133, 134 are embedded within the material 113, comparable to the embodiment of Fig. 3.

In one embodiment, the driver circuit 150 further comprises the temperature sensor 153. The driver circuit 150 may be equipped to initialize a measurement by reading out the temperature sensor 153 and the first capacity and/or the second capacity and further equipped to assign changes in the first capacity and/or the second capacity to a temperature change. This may particularly also affect the method of operation for the optoelectronic component 100. During an initialization, a temperature distribution within the optoelectronic component 100 may be assumed to be uniform. Therefore, the measured capacities may be related to the temperature value obtained by the temperature sensor 153. Any changes in the capacities after initialization may then be assigned to temperature changes. With the approach of Fig. 5 and 6 as well as the approach of Fig. 4 these temperature changes may also be spatially resolved . In one embodiment, the driver circuit 150 is equipped to evaluate at least two capacities 131, 132, 133, 134 and to spatially locate an area of the pixel array 111 with increased temperature.

In the embodiments of Fig. 3 and 6 the first electrodes 121,

122, 123, 124 and/or the second electrodes 125, 126, 127, 128 are at least partially arranged within the optoelectronic semiconductor chip 110. In the embodiments of Fig. 1,2, 4 and 5 the first electrodes 121, 122, 123, 124 and/or the second electrodes 125, 126, 127, 128 are at least partially arranged at side surfaces 114 of the optoelectronic semiconductor chip 110. In all these embodiments, the first electrodes 121, 122,

123, 124 and/or the second electrodes 125, 126, 127, 128 may have a height similar to the optoelectronic semiconductor chip 110. The height may be measured in a third direction which is perpendicular to first extension direction 115 and second extension direction 116.

In one embodiment the first electrodes 121, 122, 123, 124 and/or the second electrodes 125, 126, 127, 128 comprise a metal. The first electrodes 121, 122, 123, 124 and/or the second electrodes 125, 126, 127, 128 may also comprise a semiconductor material, particularly a doped semiconductor material .

Fig. 7 shows a cross section of the embodiment of the optoelectronic component 100 of Fig. 3. The cross section particularly shows the optoelectronic component 100 in the first extension direction 115. The first electrodes 121, 122 are embedded within the optoelectronic semiconductor chip 110 and the pixel array 111 is arranged in between the first electrodes 121, 122. The first electrodes 121, 122 are formed in a way that a height of the first electrodes 121, 122 (measured in a third direction 117) is similar to a height of the optoelectronic semiconductor chip 110. Particularly, the first electrodes 121, 122 are only arranged within the optoe- lectronic semiconductor chip 110 and not within the driver circuit 150, on which the optoelectronic semiconductor chip 110 is arranged.

It is further noted that the optoelectronic component 100 of Fig. 6 could have a similar cross section. In this case, the further first electrodes 123, 124 could look similar to the first electrodes 121, 122. Furthermore, regarding a cross section in the second extension direction 116 could be similar to the cross section shown in Fig. 7 and the second electrodes 125, 126 as well as the further second electrodes 127, 128 could also look similar to the first electrodes 121, 122. The height of the first electrodes 121, 122 as shown in Fig. 7 may also be implemented in the embodiments of Fig. 1, 2, 4 and 5.

Fig. 8 shows a cross section of an embodiment of the optoelectronic component 100, which corresponds to the embodiment of Fig. 7 as far as no differences are mentioned in the following. The height of the first electrodes 121, 122 is smaller than the height of the optoelectronic semiconductor chip 110. However, the first capacitor 131 is still affected by a temperature change and therefore, this embodiment may still be used to measure a temperature of the optoelectronic semiconductor chip 110 and particularly the pixel array 111. Such a height of the first electrodes 121, 122 may also be implemented for the further first electrodes 123, 124 as well as the second electrodes 125, 126, 127, 128 of the embodiments of Fig. 1 to 6.

Fig. 9 shows a cross section of an embodiment of the optoelectronic component 100, which corresponds to the embodiment of Fig. 7 as far as no differences are mentioned in the following. The height of the first electrodes 121, 122 is bigger than the height of the optoelectronic semiconductor chip 110. The first electrodes 121, 122 in this case are also partially arranged within the driver circuit 150. This allows for a simplified formation of an electronic contact of the first electrodes 121, 122 with the read-out circuit 151, as this contact may be established within the driver circuit 150. Such a height of the first electrodes 121, 122 may also be implemented for the further first electrodes 123, 124 as well as the second electrodes 125, 126, 127, 128 of the embodiments of Fig. 1 to 6.

Fig. 10 shows a cross section of an embodiment of the optoelectronic component 100, which corresponds to the embodiment of Fig. 9 as far as no differences are mentioned in the following. The first electrodes 121, 122 are completely embedded in the optoelectronic semiconductor chip 110 and the driver circuit. Particularly, the first electrodes 121, 122 are partially arranged within the optoelectronic semiconductor chip 110 and partially arranged within the driver circuit 150. Therefore, the electrodes 121, 122 are not visible from the outside. Furthermore, having the first electrodes 121, 122 at least partially embedded in the driver circuit 150 also allows for a simplified formation of an electronic contact of the first electrodes 121, 122 with the read-out circuit 151, as this contact may be established within the driver circuit 150. Such a height of the first electrodes 121, 122 may also be implemented for the further first electrodes 123, 124 as well as the second electrodes 125, 126, 127, 128 of the embodiments of Fig. 1 to 6.

Fig. 11 shows a cross section of an embodiment of the optoelectronic component 100, which corresponds to the embodiment of Fig. 7 as far as no differences are mentioned in the following. The first electrodes 121, 122 are completely embedded in the driver circuit 150. This allows for easy formation of contacts. However, changes in the dielectric constant of the material 113 of the optoelectronic semiconductor chip 110 still allow for the temperature measurement described above. Such implementation of the first electrodes 121, 122 may also be used for the further first electrodes 123, 124 as well as the second electrodes 125, 126, 127, 128 of the embodiments of Fig. 1 to 6. Fig . 12 shows a top view of an embodiment of the optoelectronic component 100 . The optoelectronic component 100 comprises an optoelectronic semiconductor chip 110 and a driver circuit 150 . The optoelectronic semiconductor chip 110 comprises a pixel array 111 with a plurality of pixels 112 . To improve the clarity of Fig . 12 , only some of the pixels 112 are marked with a reference sign . The optoelectronic semiconductor chip 110 is arranged on top of the driver circuit 150 . The optoelectronic component 100 further comprises first positive electrodes 121 and first negative electrodes 122 . The first positive electrodes 121 are arranged in a finger structure in such a way that the first positive electrodes 121 are connected by a first connector 135 . The first negative electrodes 122 are arranged in a finger structure in such a way that the first negative electrodes 121 are connected by a second connector 136 . The optoelectronic semiconductor chip 110 is arranged in such a way relative to the first positive electrodes 121 and the first negative electrodes 122 that a material 113 of the optoelectronic semiconductor chip 110 acts as a dielectric of first capacitors 131 formed by one of the first positive electrodes 121 and one of the first negative electrodes 122 each . The driver circuit 150 comprises a read-out circuit 151 to read out first capacities of the first capacitors 131 . The pixels 112 are arranged in a way that the pixels 112 are arranged in between the first electrodes 121 , 122 so that a change in temperatures of the pixels 112 leads to a change of the dielectric constant of the material 113 . Particularly, in this embodiment , only the first electrodes 121 , 122 are arranged di f ferently compared to the embodiments described previously . Seven first capacitors 131 are formed by four first positive electrodes 121 and four first negative electrodes 122 . Generally, all electrode structures described with respect to Fig . 7 to 11 may be utili zed for the arrangement of the first electrodes 121 , 122 of the embodiment of Fig . 12 . The pixels 112 may have a si ze of several microns , particularly around 40 microns . The first electrodes 121 , 122 have a distance to one another of at least a pixel si ze of the pixels 112 .

Fig . 13 shows a top view of an embodiment of the optoelectronic component 100 , which corresponds to the embodiment of Fig . 12 as far as no di f ferences are mentioned in the following . One first positive electrode 121 and one first negative electrode 122 form a first capacitor 131 . The first negative electrode 122 and a further first positive electrode 123 form a further first capacitor 132 . The further first positive electrode 123 and a further first negative electrode 124 form a further first capacitor 131 . Further first positive electrodes 123 and further first negative electrodes 124 form further first capacitors . The first electrodes 121 , 122 , 123 , 124 are arranged similar to the pixels 112 of the embodiment of Fig . 12 .

The embodiment of Fig . 13 allows for a spatial resolution of temperature changes in the pixel array 111 as the first capacities of the first capacitors 131 , 132 may be read out individually . The driver circuit 150 also may comprise a power supply circuit 152 to control a current supply for the pixels 112 . The driver circuit 150 may further comprise a temperature sensor 153 . Furthermore , the driver circuit 150 may be designed as a CMOS .

Fig . 14 shows a top view of an embodiment of the optoelectronic component 100 . The optoelectronic component 100 comprises an optoelectronic semiconductor chip 110 and a driver circuit 150 . The optoelectronic semiconductor chip 110 comprises a pixel array 111 with a plurality of pixels 112 . To improve the clarity of Fig . 14 , only some of the pixels 112 are marked with a reference sign .

Fig . 15 shows a cross section of the optoelectronic component 100 of Fig . 14 . This embodiment is now explained with respect to both Fig . 14 and 15 . The optoelectronic semiconductor chip 110 is arranged on top of the driver circuit 150 . The optoe- lectronic component 100 further comprises s first positive electrode 121 and a first negative electrode 122 . The first positive electrode 121 is arranged in a finger structure on top on the optoelectronic semiconductor chip 110 . In between the fingers of the finger structure several pixels 112 are arranged . The first negative electrode 122 is arranged between the optoelectronic semiconductor chip 110 and the driver circuit 150 and therefore only visible in Fig . 15 . The optoelectronic semiconductor chip 110 is arranged in such a way relative to the first positive electrode 121 and the first negative electrode 122 that a material 113 of the optoelectronic semiconductor chip 110 acts as a dielectric of a first capacitor 131 formed by the first positive electrode 121 and the first negative electrode 122 . The driver circuit 150 comprises a read-out circuit 151 to read out first capacities of the first capacitors 131 . The pixels 112 are arranged in a way that the pixels 112 are arranged in between the first electrodes 121 , 122 so that a change in temperatures of the pixels 112 leads to a change of the dielectric constant of the material 113 . The pixels 112 may have a si ze of several microns , particularly around 40 microns . The fingers of the first positive electrode 121 have a distance to one another of at least two pixel si zes of the pixels 112 . The driver circuit 150 also may comprise a power supply circuit 152 to control a current supply for the pixels 112 . The driver circuit 150 may further comprise a temperature sensor 153 . Furthermore , the driver circuit 150 may be designed as a CMOS 154 .

The first negative electrode 122 may also be used as one electrode for a current or voltage supply of the pixels 112 . This allows for a more ef ficient design . In the embodiments according to Fig . 1 to 6 , an electrode similar to the first negative electrode 122 may be used for a current or voltage supply of the pixels 112 .

Fig . 16 shows a top view of an embodiment of an optoelectronic component 100 , which corresponds to the embodiment of Fig . 14 and 15 as far as no differences are mentioned in the following. A cross section of this embodiment would look similar to the cross section of Fig. 15. Instead of a first positive electrode 121 with a finger structure the optoelectronic component comprises a first positive electrode 121 and further first positive electrodes 123. All first positive electrodes 121, 123 are arranged on top of the optoelectronic semiconductor chip 110. The first positive electrode 121 and the first negative electrode 122 form the first capacitor 131.

The further first electrodes 123 and the first negative electrode 122 form further first capacitors 132. This again allows for a spatial resolution of the temperature measurement with the methods explained above.

In all embodiments, the terms positive electrode 121, 123, 125, 127 and negative electrode 122, 124, 126, 128 are used to distinguish between two electrodes of the capacitors 131, 132, 133, 134. However, the embodiments are not limited to these arrangements and particularly the polarity of the electrodes may be switched.

Fig. 17 shows a top view of an embodiment of an optoelectronic component 100, which corresponds to the embodiment of Fig. 6 as far as no differences are mentioned in the following.

The optoelectronic semiconductor chip 110 further comprises a shielding 118 to allow for increased accuracy during read-out of the capacitors 131, 132, 133, 134. Such shielding 118 may also be implemented for the other embodiments.

Fig. 18 shows an illumination device comprising a housing 171 and one of the embodiments of the optoelectronic component 100 as explained with respect to Fig. 1 to 17. At least one of the pixels 112 is a light emitting diode 119. Particularly, the optoelectronic component 100 comprises a plurality of light emitting diodes 119.

There may be one read-out circuit 151 for each capacitor 131, 132, 133, 134. However, it is also possible to implement one read-out circuit 151 which reads out all capacitors 131 , 132 , 133 , 134 . In this case , the read-out may be multiplexed in a way that one capacitor 131 , 132 , 133 , 134 is read-out at a time and after the read-out , one of the other capacitors 131 , 132 , 133 , 134 is read-out .

All the embodiments of the optoelectronic component 100 as well as the illumination device 170 may be operated in such a way that a temperature of the pixel array 111 is measured by an evaluation of the first capacity of the first capacitor 131 ( and further capacitors 132 , 133 , 134 , should they be present ) .

It is further possible to compare the temperature to a threshold temperature . Operating parameters of the pixel array 111 are changed when the temperature exceeds the threshold temperature . This may particularly include to reduce an operating voltage or an operating current of the pixel array 111 as well as an operating voltage or an operating current of individual pixels 112 . I f one of the embodiments that allow for spatial resolution of the temperature is used, the operating voltage or the operating current of individual pixels 112 which have higher temperature as other pixels 112 may be decreased . Particularly, the operating voltage or the operating current of the pixels 112 may be selected in a way that a temperature distribution within the pixel array 111 is uni form . Furthermore , a minimum illumination power may be selected and the operating voltage or the operating current of the pixels 112 implemented as light emitting diodes 119 may be selected in a way that both the minimum illumination power is reached and a temperature distribution within the pixel array 111 is uni form .

For an illumination device 170 , the threshold temperature may be around 120 degrees Celsius . Another threshold temperature may be around 150 degrees Celsius , for which the illumination device 170 may be shut down . Although the invention has been illustrated and described in detail by means of the preferred embodiment examples , the present invention is not restricted by the disclosed examples and other variations may be derived by the skilled person without exceeding the scope of protection of the invention .

LIST OF REFERENCE S IGNS optoelectronic component optoelectronic semiconductor chip pixel array pixel material side surface first extension direction second extension direction third direction shielding light emitting diode first positive electrode first negative electrode further first positive electrode further first negative electrode second positive electrode second negative electrode further second positive electrode further second negative electrode first capacitor further first capacitor second capacitor further second capacitor first connector second connector driver circuit read-out circuit power supply circuit temperature sensor CMOS illumination device housing

Claims

1. An optoelectronic component (100) comprising an optoelectronic semiconductor chip (110) and a driver circuit (150) , wherein the optoelectronic semiconductor chip (110) comprises a pixel array (111) with a plurality of pixels (112) , wherein the optoelectronic semiconductor chip (110) is arranged on top of the driver circuit (150) , wherein the optoelectronic component (100) further comprises a first positive electrode (121) and a first negative electrode (122) , wherein the optoelectronic semiconductor chip (110) is arranged in such a way relative to the first positive electrode (122) and the first negative electrode (122) that a material (113) of the optoelectronic semiconductor chip (110) acts as a dielectric of a first capacitor (131) formed by the first positive electrode (121) and the first negative electrode (122) , and wherein the driver circuit (150) comprises a read-out circuit (151) to read out a first capacity of the first capacitor ( 131 ) .

2. The optoelectronic component (100) according to claim 1, wherein the read-out circuit (151) is equipped to calculate a temperature from the read-out first capacity and to output a temperature value.

3. The optoelectronic component (100) according to claim 1 or 2, comprising a further first positive electrode (123) and a further first negative electrode (124) , wherein the optoelectronic semiconductor chip (110) is arranged in such a way relative to the further first electrodes (123, 124) that a material of the optoelectronic semiconductor chip (110) acts as a dielectric of a further first capacitor (132) formed by the further first electrodes (123, 124) , and wherein the driver circuit (150) comprises a read-out circuit (151) to read out a further first capacity of the further first capacitor (132) . The optoelectronic component (100) according to any of claims 1 to 3, further comprising a second positive electrode (125) and a second negative electrode (126) , wherein the optoelectronic semiconductor chip (110) is arranged in such a way relative to the second positive electrode (125) and the second negative electrode (126) that a material (113) of the optoelectronic semiconductor chip (110) acts as a dielectric of a second capacitor (133) formed by the second positive electrode (125) and the second negative electrode (126) , and wherein the driver circuit (150) comprises a read-out circuit to read out a second capacity of the second capacitor (133) . The optoelectronic component (100) according to claim 4, wherein the read-out circuit (151) is equipped to calculate a temperature from the read-out second capacity and to output a temperature value. The optoelectronic component (100) according to claim 3 or 4, comprising a further second positive electrode (127) and a further second negative electrode (128) , wherein the optoelectronic semiconductor chip (110) is arranged in such a way relative to the further second electrodes (127, 128) that a material of the optoelectronic semiconductor chip (110) acts as a dielectric of a further second capacitor (134) formed by the further second electrodes (127, 128) , and wherein the driver circuit (150) comprises a read-out circuit to read out a further second capacity of the further second capacitor (134) . The optoelectronic component (100) according to any of claims 3 to 5, wherein the optoelectronic semiconductor chip (110) has a first extension direction (115) and a second extension direction (116) , wherein the first capacitor (131, 132) is arranged in the first extension direction (115) and the second capacitor (133, 134) is arranged in the second extension direction (116) . The optoelectronic component (100) according to any of claims 1 to 7, wherein the driver circuit (150) is equipped to evaluate at least two capacities (131, 132, 133, 134) and to spatially locate an area of the pixel array (111) with increased temperature. The optoelectronic component (100) according to any of claims 1 to 8, further comprising a shielding (118) to minimize external influence on the first capacitor (131, 132) and/or the second capacitor (133, 134) . The optoelectronic component (100) according to any of claims 1 to 9, wherein the first electrodes (121, 122, 123, 124) and/or the second electrodes (125, 126, 127, 128) are at least partially arranged within the optoelectronic semiconductor chip (110) . The optoelectronic component (100) according to any of claims 1 to 10, wherein the first electrodes (121, 122, 123, 124) and/or the second electrodes (125, 126, 127, 128) are at least partially arranged at side surfaces (114) of the optoelectronic semiconductor chip (110) . The optoelectronic component (100) according to any of claims 1 to 11, wherein the first electrodes (121, 122, 123, 124) and/or the second electrodes (125, 126, 127, 128) are at least partially arranged on and/or within the driver circuit (150) . The optoelectronic component (100) according to any of claims 1 to 12, wherein the driver circuit (150) is a CMOS (154) . The optoelectronic component (100) according to any of claims 1 to 13, wherein the driver circuit (150) further comprises a temperature sensor (153) . The optoelectronic component (100) according to claim 14, wherein the driver circuit (150) is equipped to initialize a measurement by reading out the temperature sensor (153) and the first capacity and/or the second capacity and further equipped to assign changes in the first capacity and/or the second capacity to a temperature change . The optoelectronic component (100) according to any of claims 1 to 15, wherein the plurality of pixels (112) comprises a plurality of independent light emitting diodes (119) . An illumination device (170) comprising a housing (171) and the optoelectronic component (100) according to claim 16. A method of producing the optoelectronic component (100) according to any of claims 1 to 16, including the following steps:

Providing the optoelectronic semiconductor chip (110) and the driver circuit (150) ;

Forming of the first positive electrode (121) and the first negative electrode (122) in such a way relative to the optoelectronic semiconductor chip (110) that a material (113) of the optoelectronic semiconductor chip (110) acts as a dielectric of a first capacitor (131) formed by the first positive electrode (121) and the first negative electrode (122) ;

Arranging the optoelectronic semiconductor chip (110) on top of the driver circuit (150) . A method of operating the optoelectronic component (100) according to any of claims 1 to 16, wherein a temperature of the pixel array (111) is measured by an evaluation of the first capacity of the first capacitor (131) . The method of claim 19 , wherein the temperature is compared to a threshold temperature and wherein operating parameters of the pixel array ( 111 ) are changed when the temperature exceeds the threshold temperature .