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EP-4742840-A1 - ELECTRONIC BOARD WITH PLATED THROUGH HOLE AND AXIAL AND RADIAL ANNULAR PROTRUSIONS

EP4742840A1EP 4742840 A1EP4742840 A1EP 4742840A1EP-4742840-A1

Abstract

An electronic board (100) which comprises a stack (102) comprising at least one electrically insulating layer structure (104) and a plurality of electrically conductive layer structures (106, 108), wherein one of said plurality of electrically conductive layer structures (106) is provided on one main surface (110) of said at least one electrically insulating layer structure (104) and a further one of said plurality of electrically conductive layer structures (108) is provided on an opposing further main surface (112) of said at least one electrically insulating layer structure (104), a through hole (120) formed in the stack (102) and being laterally delimited by conductive material, at least one plating layer (122) provided on at least part of both opposing main surfaces (114, 116) of the stack (102) and on a lateral wall (118) of the stack (102), an axial annular protrusion (126, 128) provided at one extremity of the through hole (120), and a radial annular protrusion (130, 132, 134) provided at the lateral wall (118) of the stack (102).

Inventors

  • KLEINSCHUSTER, Harald

Assignees

  • AT & S Austria Technologie & Systemtechnik Aktiengesellschaft

Dates

Publication Date
20260513
Application Date
20241111

Claims (15)

  1. An electronic board (100), which comprises: a stack (102) comprising at least one electrically insulating layer structure (104) and a plurality of electrically conductive layer structures (106, 108), wherein one of said plurality of electrically conductive layer structures (106) is provided on one main surface (110) of said at least one electrically insulating layer structure (104) and a further one of said plurality of electrically conductive layer structures (108) is provided on an opposing further main surface (112) of said at least one electrically insulating layer structure (104); a through hole (120) formed in the stack (102) and being laterally delimited by conductive material; at least one plating layer (122) provided on at least part of both opposing main surfaces (114, 116) of the stack (102) and on a lateral wall (118) of the stack (102); an axial annular protrusion (126, 128) provided at one extremity of the through hole (120); and a radial annular protrusion (130, 132, 134) provided at the lateral wall (118) of the stack (102).
  2. The electronic board (100) according to claim 1, wherein the axial annular protrusion (126, 128) is defined at least partially by said one electrically conductive layer structure (106) and/or by said further one electrically conductive layer structure (108) and/or by the at least one plating layer (122), and/or wherein the radial annular protrusion (130, 132, 134) is defined at least partially by said one electrically conductive layer structure (106) and/or by said further one electrically conductive layer structure (108) and/or by the at least one plating layer (122).
  3. The electronic board (100) according to any of claims 1 to 2, wherein the axial annular protrusion (126, 128) and/or the radial annular protrusion (130, 132, 134) has substantially constant cross-sections along a circumference of the through hole (120).
  4. The electronic board (100) according to any of claims 1 to 3, wherein the electronic board (100) comprises a plurality of through holes (120) in the stack (102), wherein the at least one plating layer (122) is provided on a lateral wall (118) of the stack (102) delimiting each of the through holes (120), and each through hole (120) having a respective axial annular protrusion (126, 128) provided at one extremity of the respective through hole (120) and having a respective radial annular protrusion (130, 132, 134) provided at the lateral wall (118) of the stack (102) delimiting the respective through hole (120).
  5. The electronic board (100) according to any of claims 1 to 4, wherein the axial annular protrusion (126, 128) extends from the lateral wall (118) of the stack (102).
  6. The electronic board (100) according to any of claims 1 to 5, wherein the at least one plating layer (122) comprises a plurality of stacked plating layers (122', 122"), wherein in particular an outermost of said plating layers (122', 122") comprises a material being different from another material of one or more inner ones of said plating layers (122', 122").
  7. The electronic board (100) according to any of claims 1 to 6, wherein the at least one plating layer (122), in particular comprising a seed layer (122') and at least one further plating layer (122") thereon, forms at least part of the axial annular protrusion (126, 128) and/or of the radial annular protrusion (130, 132, 134).
  8. The electronic board (100) according to any of claims 1 to 7, wherein said electrically insulating layer structure (104) has, at a circumference thereof extending around the through hole (120), an irregularity (140) with respect to a respective planar main surface (112) of said electrically insulating layer structure (104), wherein in particular a part of said at least one plating layer (122) at least partially fills said irregularity (140) of said electrically insulating layer structure (104).
  9. The electronic board (100) according to any of claims 1 to 8, wherein said electrically insulating layer structure (104) has a diameter (b) smaller than a diameter (B1) of said one electrically conductive layer structure (106), including said at least one plating layer (122), and/or smaller than a diameter (B2) of said further one electrically conductive layer structure (108), including said at least one plating layer (122).
  10. The electronic board (100) according to any of claims 1 to 9, wherein said electrically insulating layer structure (104) is made of a plastic material, in particular polyimide.
  11. The electronic board (100) according to any of claims 1 to 10, wherein the at least one plating layer (122) comprises a plurality of plating layers (122', 122"), and wherein at a circumference of the through hole (120) at least one of the plurality of plating layers (122', 122") does not extend or discontinuously extends at at least one of the main surfaces (114, 116) of the stack (102).
  12. The electronic board (100) according to any of claims 1 to 11, wherein one edge of one of the plurality of electrically conductive layer structures (106, 108) covered by the at least one plating layer (122) is sharp, and/or wherein an edge of each respective of the electrically conductive layer structures (106, 108) covered by the at least one plating layer (122) is sharp.
  13. A method of manufacturing an electronic board (100), wherein the method comprises: providing a stack (102) comprising at least one electrically insulating layer structure (104) and a plurality of electrically conductive layer structures (106, 108), wherein one of said plurality of electrically conductive layer structures (106) is provided on one main surface (110) of said at least one electrically insulating layer structure (104) and a further one of said plurality of electrically conductive layer structures (108) is provided on an opposing further main surface (112) of said at least one electrically insulating layer structure (104); forming a through hole (120) in the stack (102); forming at least one plating layer (122) on at least part of both opposing main surfaces (114, 116) of the stack (102) and on a lateral wall (118) of the stack (102); forming an axial annular protrusion (126, 128) at one extremity of the through hole (120); and forming a radial annular protrusion (130, 132, 134) at the lateral wall (118) of the stack (102).
  14. The method according to claim 13, wherein the method comprises forming the through hole (120) in the stack (102) by mechanically drilling.
  15. The method according to claim 13 or 14, wherein the method comprises forming the through hole (120) in the stack (102) while the stack (102) is arranged between a bottom protection structure (144) and a top protection structure (146).

Description

Field of the Invention The invention relates to an electronic board, and to a method of manufacturing an electronic board. Technological Background In the context of growing product functionalities of electronic boards and increasing miniaturization of an electronic board such as printed circuit boards, increasingly more powerful packages are being employed, which have a plurality of contacts or connections, with smaller and smaller spacing between these contacts. In particular, electronic boards shall be mechanically robust and electrically reliable so as to be operable even under harsh conditions. Conventional approaches of forming electronic boards are still challenging. Summary of the Invention There may be a need to form a compact and reliable electronic board. According to an exemplary embodiment of the invention, an electronic board is provided which comprises a stack comprising at least one electrically insulating layer structure and a plurality of electrically conductive layer structures, wherein one of said plurality of electrically conductive layer structures is provided on one main surface of said at least one electrically insulating layer structure and a further one of said plurality of electrically conductive layer structures is provided on an opposing further main surface of said at least one electrically insulating layer structure, a through hole formed in the stack and being laterally delimited by conductive material, at least one plating layer provided on at least part of both opposing main surfaces of the stack and on at least part of a lateral wall of the stack, an axial annular protrusion provided at one extremity of the through hole, and a radial annular protrusion provided at the lateral wall of the stack. According to another exemplary embodiment of the invention, a method of manufacturing an electronic board is provided, wherein the method comprises providing a stack comprising at least one electrically insulating layer structure and a plurality of electrically conductive layer structures, wherein one of said plurality of electrically conductive layer structures is provided on one main surface of said at least one electrically insulating layer structure and a further one of said plurality of electrically conductive layer structures is provided on an opposing further main surface of said at least one electrically insulating layer structure, forming a through hole in the stack, forming at least one plating layer on at least part of both opposing main surfaces of the stack and on a lateral wall of the stack, forming an axial annular protrusion at one extremity of the through hole, and forming a radial annular protrusion at the lateral wall of the stack. In the context of the present application, the term "electronic board" may particularly denote any support structure with electric functionality. For example, the electronic board may be a printed circuit board (PCB) or the like. A PCB may be a simple layer stack and does not necessarily need to carry any component. However, the electronic board may also be a component carrier. More generally, the electronic board or PCB or the like may also be an interposer or an IC (integrated circuit) substrate. The electronic board may or may not be capable of accommodating one or more components thereon and/or therein for providing mechanical support and/or electrical connectivity and/or thermal connectivity. In other words, an electronic board may be configured as a mechanical and/or electronic and/or thermal board, for instance but not necessarily also functioning as a carrier for components. An electronic board may comprise a laminated stack, such as a laminated layer stack. In particular, an electronic board may be one of a printed circuit board, an organic interposer, and an IC (integrated circuit) substrate. An electronic board may also be a hybrid board combining different ones of the above mentioned types of electronic boards. An electronic board may be flat or plate-shaped. In the context of the present application, the term "stack" may particularly denote a flat or planar sheet-like body. For instance, the stack may be a layer stack, in particular a laminated or rolled layer stack. Such a laminate may be formed by connecting a plurality of layer structures by the application of mechanical pressure and/or heat. Preferably, the plurality of layer structures are aligned parallel on top of each other. The stack may comprise electrically conductive structures and at least one electrically insulating structure. In the context of the present application, the term "layer structure" may particularly denote a continuous layer, a patterned layer or a plurality of nonconsecutive islands within a common plane, and it may perform the function of electrical conductivity and/or electrical insulation. A layer structure may also comprise an interconnection structure which protrudes from a planar surface of the layer structure. In the context of the present