Optically functional multilayer structure and related method of manufacture

Patent metadata

Field	Value
Publication number	US-12376450-B2
Application number	US-202418883078-A
Country	US
Kind code	B2
Filing date	Sep 12, 2024
Priority date	Dec 28, 2023
Publication date	Jul 29, 2025
Grant date	Jul 29, 2025

Abstract

An integrated optically functional multilayer structure including a flexible, substrate film arranged with a circuit design including electrical conductors on a first side of the substrate film; at least one light source provided upon the first side of the substrate film and connected to the circuit design the at least one light source internally illuminates at least a portion of the structure for external perception; and an optically transmissive layer-produced upon the first side of the substrate film and the at least one light source said optically transmissive layer at least partially covering the substrate film and embedding the at least one light source; wherein the substrate film defines holes therethrough and upon one or more of them the optically transmissive layer defines an outcoupling surface, configured to redirect and reflect, incident light emitted by light sources of the at least one light source.

First claim

The invention claimed is:

1. An integrated optically functional multilayer structure, comprising:
a flexible 3D-formable thermoplastic, substrate film arranged with a circuit design comprising at least a number of electrical conductors on a first side of the substrate film;
at least one light source provided upon the first side of the substrate film and connected to the circuit design, said at least one light source being configured to internally illuminate at least a portion of the structure for external perception; and
an optically transmissive layer produced upon the first side of the substrate film and the at least one light source, said optically transmissive layer at least partially covering the substrate film and embedding the at least one light source;
wherein at least one of the substrate film or the optically transmissive layer defines an outcoupling surface, tilted away from a surface plane or direction of the adjacent areas of the substrate film, configured to redirect and reflect incident light emitted by one or more light sources of the at least one light source,
wherein the substrate film includes a pattern or area for outcoupling light from the internals of the structure to an environment of the structure, and
wherein the structure further comprises an electrically conductive shielding layer on a second, opposite, side of the substrate film, disposed upon at least one intermediate layer including an adhesive layer and at least one additional layer including a further adhesive layer, including an adhesive tape layer, on a side of the shielding layer opposite to the side facing the substrate film and configured to face and contact an external and potentially electrically conductive host surface.

2. The structure of claim 1 , wherein the outcoupling surface comprises one or more light processing or redirecting features.

3. The structure of claim 1 , wherein the substrate film defines one or more holes therethrough, wherein the outcoupling surface is defined by the optically transmissive layer upon the one or more holes.

4. The structure of claim 3 , further comprising, in connection with said one or more holes, a greater cavity limited by at least the outcoupling surface of the optically transmissive layer and/or side walls of the substrate film defining the hole, said cavity being filled with fluid or with molded material.

5. The structure of claim 1 , wherein the substrate film comprises at least one elongated bridge portion hosting a part of the circuit design providing electrical connection to the at least one light source, and wherein the substrate film comprises an island portion, at least partially separated from other portion of the substrate film by one or more of said one or more holes while remaining connected thereto by the at least one bridge portion.

6. The structure of claim 5 , further comprising at least one light directing or scattering feature configured to direct or spread incident light upon the bridge portion of the substrate film, said at least one light directing or scattering feature comprising printed diffusive ink, diffusive surface relief pattern, and/or diffusive particles.

7. The structure of claim 1 , wherein the optically transmissive layer defines a recess or protrusion, substantially upon at least one of the one or more holes extending away from the substrate film and/or in the optical path of light incident and reflected from the outcoupling surface, and wherein the outcoupling surface, recess or protrusion in the transmissive layer, and associated light exit area on the outer surface of the structure are mutually aligned substantially in the thickness direction of the structure or sloped or otherwise diverging therefrom.

8. The structure of claim 1 , further comprising an optically masking and opaque constituent layer.

9. The structure of claim 8 , wherein the substrate film and the optically transmissive layer define an injection hole extending through both and being filled with material of the constituent layer provided through the injection hole.

10. The structure of claim 1 , further comprising a further film on a side of the optically transmissive layer opposite to the side facing the substrate film, said further film facing the use environment and potential user of the structure, said structure further comprising a molded shell layer on the further film.

11. The structure of claim 10 , wherein the further film comprises optical masking capacity providing translucent or opaque surface or volume, including a dyed or pigmented surface or volume, one or more light processing features.

12. The structure of claim 1 , wherein the substrate film comprises, on the first side and/or opposite second side thereof, at least one functional element selected from the group consisting of: data processing element, SIP (system-in-a-package), photovoltaic cell, energy reservoir, capacitor, supercapacitor, memory element, sensor, electrode, connector including an electrical connector, capacitive sensor or sensing element, force sensor or sensing element, pressure sensor or sensing element, light sensor or sensing element, strain gauge, heating or de-icing element, and a camera.

13. The structure of claim 12 , further comprising a molded layer on the second side of the substrate film, at least partially embedding one or more of the at least one functional element.

14. The structure of claim 12 , wherein part of the circuit design extends to the second side of the substrate film and electrically connects with the at least one functional element thereon.

15. The structure of claim 1 , wherein the shielding layer is electrically connected to the circuit design on the first substrate film.

16. A method for manufacturing an integrated optically functional multilayer structure, comprising:
obtaining a flexible, 3D-formable and thermoplastic, substrate film;
providing at least a first side of the substrate film with a circuit design comprising a number of electrical conductors by printed electronics technology;
arranging at least one light source upon the first side of the substrate film as connected to the circuit design; and
producing through molding including injection molding, high pressure molding, low pressure molding, silicone molding or using one or more other manufacturing methods, an optically transmissive layer upon the first side of the substrate film and the at least one light source, said optically transmissive layer at least partially covering the substrate film and embedding the at least one light source,
wherein the further method comprises establishing a light outcoupling surface, at least partially tilted away from a surface plane or direction defined by adjacent areas of the substrate film, from at least one of said substrate film or optically transmissive layer,
wherein the method further comprises obtaining the substrate film and providing the substrate film with a pattern or area for outcoupling light from the internals of the structure to an environment of the structure, and
wherein the structure further comprises an electrically conductive shielding layer on a second, opposite, side of the substrate film, disposed upon at least one intermediate layer including an adhesive layer and at least one additional layer including a further adhesive layer, including an adhesive tape layer, on a side of the shielding layer opposite to the side facing the substrate film and configured to face and contact an external and potentially electrically conductive host surface.

17. The method of claim 16 , wherein the substrate film is obtained as c

Assignees

• Tactotek Oy

Inventors

• Kärnä Miikka
• Hänninen Ilpo
• Yrjänä Samuli
• Koivikko Simo

Classifications

• G02B6/0073

  Light emitting diode [LED] · CPC title

• G02B6/0065

  Manufacturing aspects; Material aspects · CPC title

• G02B6/0041

  provided in the bulk of the light guide · CPC title

• G02B6/0036

  2-D arrangement of prisms, protrusions, indentations or roughened surfaces · CPC title

• G02B6/0021

  for housing at least a part of the light source, e.g. by forming holes or recesses · CPC title