Method of producing optoelectronic components and surface-mounted optoelectronic component

• US 10,490,707 B2
• Filed: 05/06/2016
• Issued: 11/26/2019
• Est. Priority Date: 05/13/2015
• Status: Active Grant

• Current Assignee: OSRAM OLED GMBH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Herrmann, Siegfried
• Primary Examiner(s): Han, Jonathan
• Application Number:
  US15/573,529
• Publication Number:
  US 20180122997A1
• Time in Patent Office: 1,299 Days
• Field of Search: 257 98, 438 27, 438 29, 204600
• CPC Class Codes: H01L 21/568 Temporary substrate used as encapsulation process aid H01L21/4832 and H01L21/566 take precedence
• CPC Class Codes: H01L 2224/04105 Bonding areas formed on an encapsulation of the semiconductor or solid-state body, e.g. bonding areas on chip-scale packages
• CPC Class Codes: H01L 2224/19 Manufacturing methods of high density interconnect preforms
• CPC Class Codes: H01L 2224/24 of an individual high density interconnect connector
• CPC Class Codes: H01L 2224/82 by forming build-up interconnects at chip-level, e.g. for high density interconnects [HDI]
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 2924/18162 of a chip with build-up interconnect
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• CPC Class Codes: H01L 2933/0025 relating to coatings
• CPC Class Codes: H01L 2933/0033 relating to semiconductor body packages
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/385 the electrode extending at least partially onto a side surface of the semiconductor body
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/54 having a particular shape

Abstract

A method of producing optoelectronic components includes A) providing a carrier and optoelectronic semiconductor chips including contact elements arranged on a contact side of the semiconductor chip; B) applying the semiconductor chips laterally next to one another on to the carrier, wherein the contact sides face the carrier during application; C) applying an electrically-conductive layer at least on to subregions of the sides of the semiconductor chip not covered by the carrier; D) applying a protective layer at least on to subregions of side surfaces of the semiconductor chips running transversely to the contact surface; E) electrophoretically depositing a converter layer on to the electrically-conductive layer, wherein the converter layer is configured to convert at least part of radiation emitted by the semiconductor chip into radiation of a different wavelength range; and F) removing the electrically-conductive layer from regions between the converter layer and the semiconductor chips.

Claims

1. A method of producing optoelectronic components comprising:

A) providing a carrier and a multitude of separated, unconnected optoelectronic semiconductor chips, wherein each semiconductor chip comprises contact elements for external electrical contacting arranged on a contact side of the semiconductor chip;

B) applying the semiconductor chips laterally next to one another on to the carrier, wherein the contact sides are made to face the carrier during application;

C) applying an electrically-conductive layer at least on to subregions of the sides of the semiconductor chips not covered by the carrier, wherein the electrically-conductive layer is of contiguous design;

D) applying a protective layer at least on to subregions of side surfaces of the semiconductor chips running transversely to the contact surface;

E) electrophoretically depositing a converter layer on to the electrically-conductive layer, wherein the converter layer is configured to convert at least part of radiation emitted by the semiconductor chips into radiation of a different wavelength range during the intended operation; and

F) removing the electrically-conductive layer from regions between the converter layer and the semiconductor chips, wherein

a connecting layer is applied on to the carrier and, during application in step B), the contact elements are pressed into the connecting layer deep enough that the contact elements are protected from being covered by the electrically-conductive layer in step C), or

a protective frame is applied on to the carrier for each semiconductor chip and, during application in step B), the semiconductor chips are placed on the carrier such that the contact elements are at least partially enclosed by the corresponding protective frame, and in step C), the protective frame prevents the contact elements from being covered by the electrically-conductive layer.

2. The method according to claim 1, wherein

in step F), the protective layer prevents the electrically-conductive layer from being removed in regions covered by the protective layer,

in step E), the regions of the electrically-conductive layer covered by the protective layer remain free of the converter layer, and

the electrically-conductive layer is reflective for light emitted by the semiconductor chips during operation.

3. The method according to claim 2, wherein

in step C), the electrically-conductive layer is applied on to all sides of the semiconductor chips not covered by the carrier and thereby in each case covers the side surfaces by at least 90%, and

in step D), free spaces located between two neighboring semiconductor chips are filled with the protective layer, wherein the protective layer is arranged laterally around the semiconductor chips such that all side surfaces of the semiconductor chips are in each case covered by the protective layer by at least 90%.

4. The method according to at least claim 1, wherein, in step D), in each case one radiation exit surface opposite the contact side of the semiconductor chips remains at least partially free of the protective layer.

5. The method according to claim 1, wherein

the connecting layer comprises or consists of a thermoplastic material, and

after step F), the semiconductor chips are detached from the carrier and singulated.

6. The method according to claim 1, wherein

in step F), the electrically-conductive layer is removed by a wet-chemical process,

the electrically-conductive layer comprises at least one metal or is formed of at least one metal,

in step F), the metal is partially or completely converted into a salt of the metal by a chemical reaction,

after step F), the mole fraction of the salt in the converter layer is 0.001% to 2%.

7. The method according to claim 1, wherein

the converter layer has a homogenous layer thickness with maximum thickness deviations of 5% from an average value of the layer thickness along its entire extent on the semiconductor chips,

after step F), the layer thickness of the converter layer is 70 μ

m at most, and

after step F), the converter layer extends contiguously, continuously and without interruptions on the semiconductor chips.

8. The method according to claim 1, wherein

the converter layer consists of a powder of converter particles, and

after step F), the converter layer is enclosed by an encapsulation layer that prevents the converter layer from chipping off or detaching from the semiconductor chip.

9. The method according to claim 1,

wherein the protective layer comprises or consists of a white plastic material,

the electrically-conductive layer has a layer thickness of 100 nm to 500 nm, and

a layer thickness of the protective layer on the side surfaces is 10 μ

m to 100 μ

m.

10. The method according to claim 1, wherein the carrier is a circuit board on which the semiconductor chips electrically connect and are mechanically attached in step B).

11. The method according to claim 1, wherein

the semiconductor chips are sapphire flip-chips with in each case a sapphire growth substrate stabilizing the semiconductor chip and a semiconductor layer sequence grown on the sapphire growth substrate, and

the contact elements are arranged on a side of the semiconductor layer sequence facing away from the sapphire growth substrate.

12. A surface-mountable optoelectronic component comprising:

an optoelectronic semiconductor chip with exposed contact elements for external electrical contacting of the component, wherein the contact elements are arranged on a joint contact side of the semiconductor chip,

a converter layer formed contiguously, continuously and without interruptions and covering a radiation exit surface opposite the contact side by at least 90%,

an encapsulation layer applied on to the converter layer which completely covers and encloses the converter layer, and

an electrically-conductive layer on side surfaces of the semiconductor chip extending transversely to the contact side, wherein

the converter layer is configured to convert at least part of a radiation emitted by the semiconductor chip into radiation of a different wavelength range during the intended operation of the component,

the converter layer has a homogenous layer thickness along its entire extent on the semiconductor chip with maximum thickness deviations of 5% from an average value of the layer thickness,

the layer thickness of the converter layer is at most 70 μ

m,

the converter layer is a powder of converter particles, which is held on to the semiconductor chip by the encapsulation layer,

the electrically-conductive layer has a layer thickness of 100 nm to 500 nm, covers all side surfaces of the semiconductor chip in each case by at least 90% and has a reflectivity of at least 80% to the radiation emitted by the semiconductor chip, and

the radiation exit surface is at least partially free of the reflective, electrically-conductive layer.

13. The optoelectronic component according to claim 12, wherein the converter layer comprises a salt of a metal, the mole fraction of which in the converter layer is 0.001% to 2%.

14. The optoelectronic component according to claim 12, wherein

a protective layer is applied on to the electrically-conductive layer and extends around the semiconductor chip without interruptions, and

the protective layer comprises or consists of a white plastic material.

15. A method of producing optoelectronic components comprising:

A) providing a carrier and a multitude of optoelectronic semiconductor chips, wherein each semiconductor chip comprises contact elements for external electrical contacting arranged on a contact side of the semiconductor chip;

B) applying the semiconductor chips laterally next to one another on to the carrier, wherein the contact sides are made to face the carrier during application;

C) applying an electrically-conductive layer at least on to subregions of the sides of the semiconductor chips not covered by the carrier, wherein the electrically-conductive layer is of contiguous design;

D) applying a protective layer at least on to subregions of side surfaces of the semiconductor chips running transversely to the contact surface;

E) electrophoretically depositing a converter layer on to the electrically-conductive layer, wherein the converter layer is configured to convert at least part of a radiation emitted by the semiconductor chips into radiation of a different wavelength range during the intended operation; and

F) removing the electrically-conductive layer from regions between the converter layer and the semiconductor chips, wherein

during removal of the electrically-conductive layer in step F), the protective layer covers regions of the electrically-conductive layer and prevents the electrically-conductive layer from being removed in the regions covered by the protective layer,

in step E), the regions of the electrically-conductive layer covered by the protective layer remain free of the converter layer, and

the electrically-conductive layer is reflective for light emitted by the semiconductor chips during operation.