Optical device and method for producing an optical device
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-01-27
- Publication Date
- 2026-08-13
Smart Images
Figure EP2026051975_13082026_PF_FP_ABST
Abstract
Description
[0001] Jenoptik Optical Systems GmbH LO-24-029-P-WO 1
[0002] Optical device and method for manufacturing an optical device
[0003] The invention relates to a method for manufacturing an optical device and an optical device.
[0004] In optical devices that can emit light or are illuminated, individual areas of these devices can reflect or scatter light. This reflected or scattered light can then cause light sensors to malfunction or produce inaccurate measurements.
[0005] Against this background, the approach presented here introduces a method for manufacturing an optical device and an optical device according to the main claims. Advantageous embodiments and further developments of the invention are described in the following dependent claims.
[0006] A method for manufacturing an optical device is presented, comprising a step of providing a printed circuit board with at least one semiconductor device mounted thereon. The semiconductor device can be configured to emit light in a light-emitting region, wherein the semiconductor device and / or the printed circuit board is configured to emit and / or reflect unwanted stray light in at least one stray light region. The method also includes a step of applying an absorption material. The absorption material can be placed at least partially on a stray light region to prevent the emission of stray light from the optical device during operation, wherein the light-emitting region is kept clear during the application step.In the provisioning step, a printed circuit board (PCB) is provided in which the semiconductor component is arranged in a cavity located in the PCB. In the deposition step, the absorption material is at least partially introduced into the cavity, in particular, the cavity is filled.
[0007] The printed circuit board (PCB) can be a conventional rigid, flexible, or hybrid rigid-flex board. It can be made of a coated, structured glass fiber substrate, a glass substrate, or ceramic. The semiconductor component can be configured as a light source, more specifically as a light-emitting diode or laser diode. The light emission range can be [Jenoptik Optical Systems GmbH LO-24-029-P-WO 2].
[0008] The absorption material is located in an area on, around, or near the semiconductor device. The interference light area can be a region of the optical device that is not the light-emitting area. Unintentional reflection or emission of light, referred to as interference light, is to be expected from the interference light area. According to one embodiment, the absorption material can be made of plastic. Specifically, the absorption material can be shaped to suppress, prevent, or at least attenuate reflection or emission of light into or from this area. The approach presented here thus offers the advantage that no light can be reflected or emitted from the interference light area, or at least that the emission of light from the interference light area can be significantly reduced.This ensures that light sensors, which are intended to receive or evaluate light emitted from the light source, are no longer disturbed by light that can be reflected or emitted from the interfering light source. This leads to a more precise and accurate detection of the light emitted from the light source.
[0009] According to the approach presented here, the cavity can be a recess or cutout in the printed circuit board. The semiconductor device, the contact terminal, and the contact wire can all be located within the cavity. The printed circuit board can also include multiple cavities if several semiconductor devices are present. The depth of the cavity or cavities is preferably in the range of not less than 50 pm and not more than 1000 pm, and particularly advantageously between 100 pm and 300 pm. The depth can be specified in a z-direction.
[0010] The cavity can be at least partially round, oval, rectangular, or square in a top view normal to a plane of the printed circuit board (plane xy). The side walls of the cavity can be straight in cross-section (e.g., in an xz or yz plane) perpendicular to the plane of the printed circuit board. The cavity can be conical, particularly frustoconical, or also truncated pyramidal, blind-hole, or terraced. The bottom of the cavity can be flat and parallel to the plane xy. The xyz coordinates can form a Cartesian coordinate system. The bottom of the cavity can be provided with electrical conductors for contacting. One or more optoelectronic components can be located in the cavity. These components can be arranged individually, in rows or columns, or in a matrix.These components can be connected to the circuit board via solder joints and / or bond wires. Jenoptik Optical Systems GmbH LO-24-029-P-WO 3.
[0011] In one embodiment, during the provisioning step, the printed circuit board (PCB) is provided, in which at least one contact terminal and / or at least one contact wire is provided in the interference light region for contacting the semiconductor device. During the application step, the absorption material is applied at least partially to the at least one contact terminal or the at least one contact wire. The contact terminal can, for example, be formed as a surface on a board or a component. The contact wire can connect the contact terminal to the semiconductor device. The absorption material can be applied to the contact terminal and the contact wire to block or suppress light emanating from them or light reflected from them. The contact wire(s) can represent interference light regions from which interference light can be reflected.The optical device can also have multiple contact terminals and multiple contact wires. Specifically in the area of these contact terminals or contact wires, which are often made of or contain a material with high reflectivity, such as gold or silver, for reasons of good electrical conductivity, reflections of light and thus stray light can be efficiently prevented.
[0012] In one embodiment, a viscous and / or liquid material can be applied as an absorption material to the at least one area affected by stray light during the application step. In particular, a silicone material, an epoxy resin, or an adhesive is used as the material. The viscous or liquid absorption material can be hardened by a drying process. The state of the absorption material allows for better application and prevents potential gaps through which stray light could pass or be reflected.
[0013] In the application step, the absorption material can be sprayed or poured onto the at least one area affected by stray light, according to one embodiment.
[0014] Furthermore, according to one embodiment, in the application step, a material that is opaque to optical light or non-reflective can be applied as an absorption material to at least one area of stray light. The material can have a surface texture or roughness that is greater than or on the same order of magnitude as the wavelength of light. The surface roughness can be greater than 0.3 pm, advantageously 0.5 pm to 50 pm, and particularly advantageously 1 pm to 10 pm. Jenoptik Optical Systems GmbH LO-24-029-P-WO 4
[0015] Surface roughness can be determined as the arithmetic mean roughness Ra from a primary surface profile using a high-pass filter with a cutoff wavelength of 1 pm and a low-pass filter with a cutoff wavelength of 3 pm to 10 pm, advantageously 5 pm. The filters can be represented as linear profile filters according to DIN EN ISO 16610-21. Such roughness of the absorption material allows unwanted light to be absorbed even more effectively.
[0016] In addition, according to one embodiment, the absorption material can be applied in such a way that it extends beyond a major surface of the printed circuit board or beyond the height of the light-emitting area from the board. This increase in the amount of absorption material can conceal and prevent gaps between the printed circuit board and the absorption material, thus improving the suppression of stray light.
[0017] Because of the cavity according to the invention, casting dimensions can be produced reproducibly. This results in increased accuracy and also reduces manufacturing costs.
[0018] A further advantageous embodiment of the approach presented here involves applying the absorption material in such a way that it exhibits the aforementioned surface roughness. Such an embodiment offers the advantage that the absorption material is particularly low-reflective.
[0019] According to a further embodiment, in the application step, a potting material, which can also be referred to as a potting compound, can be applied at least partially to the absorption material and / or the light-emitting area, in particular wherein the potting material is a transparent material and / or wherein the potting material is applied in such a way that the absorption material and / or the light-emitting area is protected against environmental influences. This allows components in the light-emitting area and / or the absorption material to be protected against environmental influences, while still ensuring the desired function of the optical device and increasing its service life. For example, certain surfaces can also be made planar using the potting material, so that liquids, for instance, are absorbed as efficiently as possible. Jenoptik Optical Systems GmbH LO-24-029-P-WO 5
[0020] can be derived from an area such as the light emission area, thereby ensuring robust functionality of the optical device.
[0021] A further advantage of the approach presented here is a control unit configured to execute and / or control the steps of a variant of the method presented here in corresponding units. According to one embodiment, the control unit can be configured to read input signals and, using these input signals, determine and provide output signals. An input signal can, for example, be a sensor signal readable via an input interface of the control unit. An output signal can be a control signal or a data signal that can be provided at an output interface of the control unit. The control unit can be configured to determine the output signals using a processing instruction implemented in hardware or software.For example, the control unit can include a logic circuit, an integrated circuit or a software module and can be implemented as a discrete component or comprised of a discrete component.
[0022] Furthermore, an optical device is presented comprising a printed circuit board with at least one semiconductor device arranged thereon in a cavity, configured to emit light in a light-emitting region, wherein the semiconductor device and / or the printed circuit board is configured to emit and / or reflect unwanted stray light in at least one stray light region, and at least one absorption material, which is applied at least partially into the cavity onto the at least one stray light region to prevent the emission of stray light from the optical device during operation, wherein the absorption material is arranged such that the light-emitting region is kept clear. The absorption material should, for example, be electrically insulating but may be thermally conductive, e.g., with a thermal conductivity > 0.5 W / (m*K).
[0023] The optical device can be designed as a surface-mountable component with electrical back contacts on the reverse side of the printed circuit board (PCB) for contacting the optical device. For this purpose, the bond pads on the front side of the PCB, i.e., the side on which the semiconductor device is located, can be through-hole plated to the back contacts. One or more back contacts can also be provided for contacting the substrate. A substrate contact can be provided, for example, if the substrate of the semiconductor chip is configured as the cathode or the anode. Jenoptik Optical Systems GmbH LO-24-029-P-WO 6
[0024] In the following description of advantageous embodiments of the present invention, the same reference numerals are used for the elements shown in the various figures that have the same or similar effects, thus omitting a repeated description of these elements. Embodiments of the invention are shown purely schematically in the drawings and are described in more detail below. It shows
[0025] Fig. 1 shows a schematic representation of an embodiment of an optical device;
[0026] Fig. 2 shows another schematic representation of an embodiment of an optical device;
[0027] Fig. 3 shows another schematic representation of an embodiment of an optical device;
[0028] Fig. 4 shows a flowchart of an embodiment of a method for manufacturing an optical device;
[0029] Fig. 5 shows a block diagram of an exemplary embodiment of a control unit;
[0030] Figs. 6A to C show representations of an optical device according to an embodiment in which a potting material is applied at least partially over the absorption material and the light emission area;
[0031] Fig. 7 shows a perspective view of another embodiment of an optical device; and
[0032] Fig. 8 shows a perspective view of the embodiment of the optical device shown in Fig. 7.
[0033] Fig. 1 shows a schematic representation of an embodiment of an optical device 100. The optical device 100 is arranged here on a printed circuit board 110, wherein the optical device 100 can also be used as a surface-mounted component. Jenoptik Optical Systems GmbH LO-24-029-P-WO 7
[0034] This can be understood as follows. A semiconductor component 120 is arranged on the circuit board 110. The semiconductor component 120 has at least one light-emitting area 130. An absorption material 140 surrounds the semiconductor component 120, covering an area of stray light not shown in Figure 1. The circuit board 110 is designed as a circuit carrier. In principle, it is also conceivable that several light-emitting areas 130 could be provided, around which one (or more) corresponding absorption material(s) 140 could optionally be arranged.
[0035] Suitable circuit carriers include conventional rigid, flexible, or hybrid rigid-flex circuit boards, coated and structured glass or fiber optic substrates, and ceramic multilayer circuit boards. The semiconductor component 120 on the circuit board 110 emits light during operation of the optical device 100, with the light emission area 130 being the only area in which light is visible or intended to be visible. To prevent light from escaping from the semiconductor component 120 at any location other than the light emission area, the absorption material 140 is applied to the circuit board 110. The semiconductor component 120 includes the stray light area (not shown in Fig. 1), from which stray light may be emitted or reflected during operation of the optical device 100, potentially and undesirably.
[0036] The absorption material 140 is applied to the stray light area to prevent stray light emission without obscuring the light emission area 130. To manufacture the optical device 100, the absorption material 140 is, for example, injected into a cavity in the circuit board 110, or even sprayed onto the cavity or stray light area. The cavity can, for example, be designed as a blind hole. The bottom of the cavity can, for example, be flat. The side walls can, for example, be in the form of a pyramid or truncated cone, and the cavity can also be terraced (as, for example, in the Colosseum in Rome). It is also conceivable that the cavity could have been manufactured by machining, forming, or deformation, or by layer-by-layer application (e.g., by screen printing, 3D printing, or selective laser sintering (SLS), for example).with metal powder / plastic powder / ceramic powder, or by printed circuit board lamination process) or by selective layer-by-layer removal (e.g. by etching or electrical erosion or laser ablation).
[0037] The absorption material 140 is made, for example, of silicone, epoxy resin, or adhesive. Regardless of the material from which the absorption material 140 is ultimately made, it should be opaque or non-reflective. The absorption material 140 is located in the stray light range. Jenoptik Optical Systems GmbH LO-24-029-P-WO 8
[0038] The arrangement is intended to prevent any light other than that within the light beam area 130 from being visible from outside the optical device 100. According to this embodiment, the absorption material 140 extends beyond the circuit board 110.
[0039] On the back side of the circuit board 110, backside contacts 160 are provided. A portion of the backside contacts (here exactly two) are electrically connected to one of the bond pads 220, see Fig. 2 and Fig. 3. This connection can be made by means of vias and / or conductor tracks (not shown). Another portion of the backside contacts (here exactly one) serves instead for contacting the substrate. In this case, the optical device 100 can be designed as a surface-mountable component.
[0040] Fig. 2 shows another schematic representation of an embodiment of an optical device 100. The optical device 100 is shaped like the device described in Fig. 1, but is shown without the absorption material 140. For clarity, the back contacts 160 are also omitted. The optical device 100 again includes the circuit board 110 and the semiconductor device 120. In this representation, the interference area 200 is not obscured by the absorption material. Such interference area 200 can be understood as an exemplary side surface of the chip; however, it is also conceivable that the interference area 200 could be at least one side surface of the chip or even a part of the chip surface outside the emitter area(s) (if several are present).
[0041] Furthermore, a cavity 210 is visible, into which the absorption material shown in Figure 1 is injected. Figure 2 also shows several contact connections 220 in the cavity 210. The contact connections 220, designed as bond pads, are connected to corresponding bonding surfaces 150 on the semiconductor device 120 by means of contact wires 230. According to this embodiment, the cavity 210 is round. The cavity 210 has a side wall 240 at a step between the circuit board 110 and the cavity 210. The side wall 240 is cylindrical in shape. Alternatively, the side wall 240 can also be slightly curved or conical. This improves reliable stabilization of the covering material on the stray light area 200. Jenoptik Optical Systems GmbH LO-24-029-P-WO 9
[0042] The contact wires 230 used for electrical contacting, for example shaped as conductors, solders and wires, often act as reflectors (diffuse or directional) in optical systems and thus generate stray or scattered light. To suppress this, according to the approach presented here, all or at least many of the reflective surfaces are covered with the absorption material that absorbs at the useful wavelength.
[0043] Fig. 3 shows another schematic representation of an embodiment of an optical device 100. According to this embodiment, the optical device 100 is shaped like the optical device described in Fig. 1. However, neither the absorption material nor the semiconductor component on the circuit board 110 are shown here. For the sake of clarity, the back contacts are also omitted. This reveals a total of three contact terminals 220, which are arranged in the cavity 210. These contact terminals can also be made, for example, of a reflective material such as gold or silver, which have good electrical conductivity properties and are therefore frequently used as contact materials in the semiconductor industry.
[0044] Fig. 4 shows a flowchart of an embodiment of method 400 for manufacturing an optical device. Method 400 consists of two steps: step 401, providing a printed circuit board, and step 403, applying an absorption material. In step 401, providing a printed circuit board, a printed circuit board is provided with at least one semiconductor device arranged thereon, which is configured to emit light in a light-emitting region, wherein the semiconductor device and / or the printed circuit board is configured to emit and / or reflect unwanted interference light in at least one interference light region. In step 403, applying the absorption material, the absorption material is alternatively applied in the cavity in which the absorption material is then at least partially arranged.
[0045] In step 403 of the application process, the absorption material is applied at least partially to a stray light area to prevent stray light from being emitted by the optical device during operation, whereby the light emission area is kept clear in step 403. The absorption material is applied at least partially to the at least one contact terminal and / or the at least one contact wire. Alternatively, in step 403, viscous and / or liquid material is applied as absorption material to the at least one stray light area. The absorption material is applied to the at least one stray light area. Jenoptik Optical Systems GmbH LO-24-029-P-WO 10
[0046] sprayed or poured on. Alternatively, in step 403 of the application process, the absorption material is designed as a material that is opaque and / or non-reflective to optical light and extends beyond the height of the light emission area from the circuit board.
[0047] Figure 5 shows a block diagram of an embodiment of a control unit 500 for manufacturing an optical device 100, wherein the control unit 500 comprises a unit 501 for providing a printed circuit board with at least one semiconductor device arranged thereon, which is configured to emit light in a light emission area, wherein the semiconductor device and / or the printed circuit board is configured to emit and / or reflect unwanted interference light in at least one interference light area. The control unit 500 further comprises a unit 503 for applying an absorption material at least partially to an interference light area in order to prevent the emission of interference light from the optical device during operation of the optical device, whereby the light emission area is kept clear during application.
[0048] Fig. 6A shows a cross-sectional view in an xz section of an optical device 100 according to an exemplary embodiment. Here, the semiconductor device 120 is arranged on the circuit board 110 (or more generally, a support substrate) and is partially covered by the absorption material 140. This absorption material 140 is, for example, dark or black and thus prevents the emission of stray light from one or more areas of interference. To ensure encapsulation and / or protection of the optical device 100 against environmental influences, at least a portion of the semiconductor device 120 in the light-emitting area 130 is coated or potted with the potting material 600, which also partially covers or obscures a portion of the absorption material 140.To enable the desired emission of light from the light emission area 130, the potting material 600 should be transparent to the light that is to be emitted via the light emission area 130. For example, the potting material 600 can also be cast onto or into the cavity 210 in such a way that a planar surface is created on a surface 610 of the optical device 100, on which, for example, dirt particles or liquids can easily run off without significantly impairing the functionality of the optical device 100.
[0049] Materials for the transparent potting compound can include, for example, silicone compounds, epoxy resins, adhesives, etc., which are applied in a liquid or viscous state. The application process of the potting compound, as well as the absorption material, can be described in Jenoptik Optical Systems GmbH LO-24-029-P-WO 11.
[0050] This is achieved by directed dispensing or jetting. During application of the potting compound, some flow occurs, which can be contained by the side walls 240 of the cavity 210. A subsequent curing / setting process (e.g., due to temperature / humidity / UV light / reactive processes) leads to the solidification of the potting compound.
[0051] Figure 6B shows an enlarged view of the structure depicted in the designated section of Figure 6A. It can also be seen that, for example, further structures or components of the optical device 100, such as a contact terminal 230, are embedded or protected in the absorption material 130 before the potting material 600 is introduced and the cavity 210 is sealed.
[0052] Figure 6C shows a top view of the optical device 100, from which it can be seen that the semiconductor device 120 is covered by several layers of materials such as the absorption material 140 and the potting material 600.
[0053] Fig. 7 shows a perspective view of another embodiment of an optical device 100. It can be seen that several semiconductor devices 120, each with a light-emitting area 130, are provided on the circuit board 110 and are arranged in a cavity, which is arranged in a matrix-like, specifically linear, configuration relative to one another. The semiconductor devices 120 are surrounded by a common absorption material 140, which enables extended functionality of the optical device 100.
[0054] Fig. 8 shows a perspective view of the embodiment of the optical device 100 shown in Fig. 7, but now in a form before the absorption material 140 has been applied. It can be seen that the individual semiconductor components 120 can be contacted via contact terminals 220 using the contact wires (bond wires) not shown in Fig. 8. After the contact wires (bond wires) have been applied, the absorption material 140 is then applied, resulting in the optical device 100 as shown in Fig. 7. Optionally, a transparent potting compound can then be applied to the light-emitting areas 130 and, if necessary, to the absorption material. Jenoptik Optical Systems GmbH
[0055] LO-24-029-P-WO
[0056] Reference symbol list
[0057] 100 optical devices
[0058] 110 circuit boards
[0059] 120 semiconductor components
[0060] 130 light emission range
[0061] 140 absorption material
[0062] 150 Bond areas
[0063] 160 backside contacts
[0064] 200 stray light range
[0065] 210 Cavity
[0066] 220 contact points, bond pads
[0067] 230 contact wires
[0068] 240 side wall
[0069] 400 Methods for manufacturing an optical device
[0070] Step 401 of providing a printed circuit board
[0071] Step 403 of applying an absorption material
[0072] 500 Control unit for manufacturing an optical device 100 501 Unit for providing a printed circuit board
[0073] 503 Unit for applying an absorption material
[0074] 600 potting compound
[0075] 610 Surface of the optical device
Claims
Jenoptik Optical Systems GmbH LO-24-029-P-WO 13 Patent claims 1. Method (400) for manufacturing an optical device (100), wherein the method (400) comprises the following steps: Providing (401) a printed circuit board (110) with at least one semiconductor device (120) arranged thereon, which is configured to emit light in a light emission area (130), wherein the semiconductor device (120) and / or the printed circuit board (110) is configured to emit and / or reflect unwanted interference light in at least one interference light area (200); Applying (403) an absorption material (140) at least partially to the at least one stray light area (200) to prevent the stray light from being emitted by the optical device (100) during operation of the optical device (100), wherein in step (403) of applying the material the light emission area (130) is kept clear, characterized by the fact that In step (401) of provisioning, a printed circuit board (110) is provided in which the semiconductor device (120) is arranged in a cavity (210) which is located in the printed circuit board and wherein in step (403) of application the absorption material (140) is at least partially introduced into the cavity (210), in particular the cavity (210) is filled.
2. Method (400) according to claim 1, wherein in step (401) of provisioning a printed circuit board (110) is provided in which at least one contact terminal (230) and / or at least one contact wire for contacting the semiconductor device (120) is provided in one of the at least one interference light areas (200), wherein in step (403) of application the absorption material (140) is applied at least partially to the at least one contact terminal (230) and / or the at least one contact wire.
3. Method (400) according to one of the preceding claims, wherein in step (403) of application a viscous and / or liquid material is applied as absorption material (140) to the at least one stray light area (200), in particular wherein Jenoptik Optical Systems GmbH LO-24-029-P-WO 14 The material used is a silicone material and / or an epoxy resin and / or an adhesive.
4. Method (400) according to one of the preceding claims, wherein in step (403) of application the absorption material (140) is sprayed and / or poured onto the at least one stray light area (200).
5. Method (400) according to one of the preceding claims, wherein in step (403) of application, a material that is opaque to optical light and / or non-reflective is applied to the at least one stray light area (200) as absorption material (140).
6. Method (400) according to one of the preceding claims, wherein in step (403) of application the absorption material (140) is applied such that the absorption material (140) extends over a main surface of the printed circuit board (110) and / or over a height of the light emission area (130) from the printed circuit board (110).
7. Method (400) according to one of the preceding claims, wherein in step (401) of provisioning a printed circuit board (110) is provided, the cavity (210) of which is at least partially round and / or oval and / or rectangular and / or square in a top view normal to a plane of the printed circuit board (110), and / or wherein side walls (240) of the cavity (210) are straight in a cross-section perpendicular to the plane of the printed circuit board (110), and / or the cavity (210) is conical, in particular frustoconical.
8. Method (400) according to one of the preceding claims, wherein in step (403) of application the absorption material (140) is applied such that the surface roughness of the absorption material (140) is greater than 0.3 pm, in particular 0.5 pm to 50 pm.
9. Method (400) according to one of the preceding claims, wherein in step (403) of application a potting material is applied at least partially to the absorption material (140) and / or the light emission area (130), in particular wherein the potting material is a transparent material and / or wherein the potting material is applied in such a way that the absorption material and / or the light emission area (130) is protected against environmental influences. Jenoptik Optical Systems GmbH LO-24-029-P-WO 10. Optical device (100) having the following features: a printed circuit board (110) with at least one semiconductor device (120) arranged thereon in a cavity (210) which is located in a printed circuit board, the semiconductor device being configured to emit light in a light emission area (130), wherein the semiconductor device (120) and / or the printed circuit board (110) being configured to emit and / or reflect unwanted interference light in at least one interference light area (200); and at least one absorption material (140) which is applied at least partially into the cavity (210) onto the at least one stray light area (200) in order to prevent the emission of stray light from the optical device (100) during operation of the optical device (100), wherein the absorption material (140) is arranged such that the light emission area (130) is kept clear.
11. Optical device (100) according to claim 10 with electrical rear contacts (160) for contacting the optical device (100) as a surface-mountable component.