US-12622095-B2 - Optical device and method for producing an optical device

US12622095B2US 12622095 B2US12622095 B2US 12622095B2US-12622095-B2

Abstract

The invention relates to a method for producing an optical apparatus ( 200 ). The method comprises a step of providing a substrate ( 210 ) on whose first main surface ( 212 ) a plurality of emission devices ( 220 ) for emitting electromagnetic radiation ( 250, 255 ) are arranged. The substrate ( 210 ) is designed as a light-emitting diode wafer and/or formed from sapphire or gallium nitride and is transparent at least for one emission wavelength of the radiation ( 250, 255 ) emitted by the emission devices ( 220 ), The method also comprises a step of applying an absorption material ( 230 ) on the side of the first main surface ( 212 ) of the substrate ( 210 ). The absorption material ( 230 ) has a photostructurable resist that absorbs at least the emission wavelength. The method further comprises a step of processing the absorbing material ( 230 ) in order to lay bare at least one emission surface ( 227 ) of each emission device ( 220 ). In this case, a position determination of surfaces to be laid bare is carried out from a second main surface ( 214 ) of the substrate ( 210 ) opposite the first main surface ( 212 ). In addition, the method comprises a step of singulating the substrate ( 210 ) into a plurality of optical apparatuses ( 200 ) by means of a separating manufacturing process, wherein each optical apparatus ( 200 ) has at least one emission device ( 220 ).

Inventors

Daniel Matthesius
Torsten Trenkler
Enrico Pertzsch

Assignees

JENOPTIK OPTICAL SYSTEMS GMBH

Dates

Publication Date: 20260505
Application Date: 20210707
Priority Date: 20200710

Claims (7)

1 . A method for producing an optical apparatus, wherein the method has the following steps: providing a substrate on whose first main surface a plurality of emission devices for emitting electromagnetic radiation are arranged, wherein the substrate is designed as a light-emitting diode wafer and/or the substrate is formed from sapphire or gallium nitride, and wherein the substrate is transparent at least for one emission wavelength of the radiation emitted by the emission devices; applying an absorption material on the side of the first main surface of the substrate, wherein the absorption material has a photostructurable resist which absorbs at least the emission wavelength; processing the absorption material in order to lay bare at least one emission surface of each emission device, wherein a position determination of surfaces to be laid bare is carried out from a second main surface of the substrate opposite the first main surface; and singulating the substrate into a plurality of optical apparatuses by means of a separating manufacturing process, wherein each optical apparatus has at least one emission device.
2 . The method as claimed in claim 1 , wherein, in the processing step, the absorption material is exposed using a photomask, is developed using a developer material, and is removed at least in the region of the at least one emission surface.
3 . The method as claimed in claim 1 , wherein, in the processing step, the absorption material is processed in order to lay bare electrical connection surfaces of each emission device and/or at least one singulation boundary.
4 . The method as claimed in claim 1 , wherein, in the providing step, a substrate is provided on whose second main surface adjustment marks for the position determination are created, or characterized by a step of creating adjustment marks for the position determination on the second main surface of the substrate.
5 . The method as claimed in claim 1 , wherein, in the providing step, a substrate is provided, whose second main surface is polished, or characterized by a step of polishing the second main surface of the substrate.
6 . The method as claimed in claim 1 , wherein a step of potting side edges of the substrate of each optical apparatus using a potting material after the step of singulating the substrate, wherein the potting material absorbs at least the emission wavelength.
7 . The method as claimed in claim 1 , wherein, in the providing step, a substrate with emission devices is provided, which are manufactured by means of a semiconductor-technological process, or characterized by a step of fabricating the emission devices on the substrate by means of a semiconductor-technological process, wherein in the semiconductor-technological process an n-doped epitaxial layer is arranged on the first main surface of the substrate, an n-contact metal as a first electrical connection surface and an active emission layer are arranged on the n-doped epitaxial layer, the active emission layer is covered with a p-doped epitaxial layer, and a p-contact metal is arranged as a second electrical connection surface on the p-doped epitaxial layer.

Description

The invention relates to a method for producing an optical apparatus, in particular for producing an optical sight, in particular a reflector sight, with at least one such optical apparatus. It furthermore relates to an optical apparatus and to an optical sight, in particular a reflector sight. There are currently various methods for suppressing secondary light-emission in optical apparatuses. For example, miniaturized metal masks can be used to cover regions of an LED chip. An absorbing layer can also be applied, for example, to a rear side of transparent substrates. For example, small, black plastic caps can also be used to cover a chip and bonding wires and thus absorb part of unwanted reflections. Document US 2011/0 298 000 A1 discloses a chip packaging process which can be used to produce optical apparatuses, in particular LED chips. Against this background, with the approach presented here, a method for producing an optical apparatus, an optical apparatus and an optical sight, in particular a reflector sight, with at least one such optical apparatus according to the main claims is presented. Advantageous configurations and developments of the invention are evident from the following dependent claims. According to embodiments, an optical apparatus can be provided in particular, during the production of which all regions of the apparatus that are no longer accessed in the further production method and/or that only allow secondary light emission to emerge can be covered in a radiation-absorbing manner in order to eliminate or at least minimize unwanted secondary light emission. The covering with an absorption material can be carried out in particular during the chip process at the wafer level in order to process a plurality or multiplicity of components in one processing step in a cost-effective manner. In other words, for example, an optical apparatus can be provided with an absorption layer that is photostructurable at the wafer level to prevent unwanted secondary light emission due to reflection and/or light guidance in the transparent substrate or in epitaxial layers. Advantageously, according to embodiments, undesired or unwanted secondary light emission in particular can be minimized or completely eliminated in an optical apparatus. A plurality of apparatuses, for example up to several thousand apparatuses, can be processed in one step. A contact grid can be present in particular in the case of standard chips, which would also remain visible when using a conventional metal mask as absorption covering and is undesirable, which can be avoided according to embodiments. The absorption material, for example a resist, can also act as a barrier for subsequent black potting of bonding wires and substrate edges or chip edges. For example, for reflector sights and similar applications, according to embodiments, optical apparatuses can be provided as LED point emitters and LED displays with precisely defined light-emitting surfaces. Secondary light emission outside of intended light-emitting surfaces which is perceivable by the user can be suppressed or reduced to a minimum. Secondary light emission can arise from a wide variety of causes, for example reflection at metal edges of the apparatus or on the LED chip, imprecise definition of light-emitting surfaces, light guidance through transparent layers and substrates or the like. The production according to embodiments is suitable in particular for point emitters and display chips on transparent substrates, since the absorption material can be precisely applied to cover all chip-level regions where secondary light emission can occur and which no longer needs to be accessed in the subsequent build-up process. Furthermore, the apparatuses can be protected from a die singulation process. In addition, the apparatus is inexpensive to produce since all apparatuses can already be finished and protected at the wafer level. A method for producing an optical apparatus is presented, the method having the following steps: providing a substrate on whose first main surface a plurality of emission devices for emitting electromagnetic radiation are arranged, wherein the substrate is transparent at least for one emission wavelength of the radiation emitted by the emission devices;applying an absorption material on the side of the first main surface of the substrate, wherein the absorption material absorbs at least one emission wavelength;processing the absorption material to lay bare at least one emission surface of each emission device, wherein a position determination of surfaces to be laid bare is carried out from a second main surface of the substrate opposite the first main surface; andsingulating the substrate into a plurality of optical apparatuses by means of a separating manufacturing process, wherein each optical apparatus has at least one emission device. According to the invention, the substrate in the method is designed as a light-emitting diode wafer and/or is f