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EP-4501079-B1 - METHOD FOR MANUFACTURING ELECTRONICS ASSEMBLY AND ELECTRONICS ASSEMBLY

EP4501079B1EP 4501079 B1EP4501079 B1EP 4501079B1EP-4501079-B1

Inventors

  • Bräysy, Vinski
  • HÄNNINEN, Ilpo
  • Apilo, Pälvi
  • HEIKKINEN, MIKKO
  • WUORI, TOPI
  • SIPPARI, Mikko
  • Alamäki, Heikki

Dates

Publication Date
20260506
Application Date
20230316

Claims (20)

  1. A method for manufacturing an electronics assembly (100), comprising: obtaining or producing (210) an electronics module (10), wherein the electronics module (10) comprises: - a first circuitry (13) on a first surface at a first side of a circuit board (11), - at least one electronics component (12) on the circuit board (11) and in electrical connection with the first circuitry (13), and - at least one first connection portion (14) on the first surface and/or an adjacent side surface at a peripheral portion of the circuit board (11), wherein the at least one first connection portion (14) is electrically connected to or is comprised in the first circuitry (13); arranging (220) the electronics module (10) on a second substrate (21) comprising a second connection portion (22) connected to a second circuitry (23) on a surface of the second substrate (21), wherein a second surface of the circuit board (11), being on the second side opposite to the first surface, faces the second substrate (21), and arranging (230) electrically conductive joint material (16) onto the first (14) and the second connection portions (22) to extend between them for electrically connecting the electronics module (10) to the second circuitry (23) via the electrically conductive joint material (16), characterized in that the second substrate (21) is a formable film or sheet, preferably of plastic material, and that the second circuitry (23) is printed on a surface of the second substrate (21).
  2. The method of claim 1, wherein the electrically conductive joint material (16) is one selected from the group consisting of: solder material, conductive adhesive, conductive ink, conductive tape or film.
  3. The method of claim 1 or 2, wherein the electrically conductive joint material (16) is at least initially dispensable, preferably flowable, such as conductive adhesive or ink, or melted or stencil printable solder material, and the arranging of the electrically conductive joint material (16) comprises dispensing it on the first and the second connection portions.
  4. The method of any one of claims 1-3, wherein the first connection portion (14) comprises one or a plurality of conductive pads at the peripheral portion on the first surface at the first side of the circuit board (11).
  5. The method of any one of claims 1-4, wherein the first connection portion (14) includes one or several castellated or plated edges or half-holes (17).
  6. The method of any one of claims 1-5, wherein the first connection portion (14) comprises one or several vias or plated holes.
  7. The method of any one of claims 1-6, wherein the arranging of the electronics module (10) comprises attaching the electronics module to the second substrate (21) by a second adhesive (24), preferably an electrically non-conductive adhesive, provided on the second side of the electronics module (10).
  8. The method of any one of claims 1-7, comprising applying a conformal coating (18), an encapsulant or a glop top layer onto the first surface to embed at least the electronics component (12).
  9. The method of any one of claims 1-8, comprising forming, such as thermoforming, the second substrate (21) at least locally from a planar shape to exhibit a non-planar or 3D shape, such as a convex and/or concave surface portion, prior to or after the arranging (220) of the electronics module on the second substrate (21).
  10. The method of any one of claims 1-9, comprising providing a trench (15), such as including or being a depression or an indentation, to the second substrate (21), the trench (15) having a shape and a lateral size such that the electronics module (10) fits laterally into the trench (15).
  11. The method of claim 10, wherein the trench (15) is provided by thermoforming the second substrate (21).
  12. The method of any one of claims 1-11, wherein the circuit board (11) comprises a rigid portion (11A) and a flex portion (11B) attached to each other, wherein the at least one first connection portion (14) is comprised in the peripheral portion of the flex portion (11B).
  13. The method of any one of claims 1-12, wherein the at least one electronics component is a connector (51) for providing electrical connection between an external entity and the first circuitry (13), preferably the connector (51) extending through a hole in the second substrate (21).
  14. The method of any one of claims 1-12, comprising arranging a third substrate (31), such as a thermoformable film or sheet, preferably of plastic material, on the opposite side of the electronics module (10) relative to the second substrate (21).
  15. The method of claim 14, wherein the at least one electronics component (12) is a segment display, such as a 7-segment, 8-segment, or 16-segment display, and wherein the third substrate (31) is attached to a surface of the segment display being on the side of the display opposite to the circuit board (11).
  16. The method of claim 14 or 15, wherein the third substrate (31) is attached to the first surface of the circuit board (11) and/or the at least one electronics component (12), such as the segment display, by third adhesive (71), such as transparent adhesive or film.
  17. The method of any one of claims 1-16, comprising removing a portion of the second substrate (21) to expose the circuit board (11) for arranging the at least one electronics component (12) on the exposed portion of the second surface.
  18. The method of any one of claims 14-17, wherein the circuit board (11) comprises a cavity (19) on the first surface, the method comprising removing a portion of the third substrate (31) to expose the cavity (19) for arranging one or several electronics components (12), such as a passive infrared sensor, to the cavity (19).
  19. The method of claim 18, comprising attaching a second circuit board (11C) to the third substrate (31) on the side facing or to be facing the electronics module (10), wherein the second circuit board (11C) comprises a through-hole, and removing a portion of the third substrate (31) to expose the through-hole for arranging one or several electronics components (12), such as a passive infrared sensor, to a cavity (19) defined by the through-hole and the circuit board (11).
  20. The method of any one of claims 1-19, comprising molding, preferably injection molding, material onto a side of the second substrate (21) having the electronics module (10) and at least partly embedding the electronics module (10).

Description

FIELD OF THE INVENTION The present invention relates in general to functional, integrated structures or electronics assemblies incorporating various functional features such as electronic, mechanical or optical elements. In particular, however not exclusively, the present invention concerns connecting electronic modules or sub-assemblies to substrates for producing such structures or assemblies. BACKGROUND There exists a variety of different stacked assemblies and multilayer structures in the context of different functional ensembles e.g. in the field of electronics and electronic products. The motivation behind the integration of functionalities involving e.g. electronics, mechanical or optical features may be as diverse as the related use contexts. Relatively often size savings, weight savings, cost savings, or just efficient integration of components is sought for when the resulting solution ultimately exhibits a multilayer nature. In turn, the associated use scenarios may relate to product packages or casings, visual design of device housings, wearable electronics, personal electronic devices, displays, detectors or sensors, vehicle interiors, antennae, labels, vehicle electronics, etc. Electronics such as electronic components, ICs (integrated circuit), and conductors, may be generally provided onto a substrate element by a plurality of different techniques. For example, ready-made electronics such as various surface mount devices (SMD) may be mounted on a substrate surface that ultimately forms an inner or outer interface layer of a multilayer structure. Additionally, technologies falling under the term "printed electronics" may be applied to actually produce electronics directly and additively to the associated substrate. The term "printed" refers in this context to various printing techniques capable of producing electronics/electrical elements from the printed matter, including but not limited to screen printing, flexography, and inkjet printing, through a substantially additive printing process. The used substrates may be flexible and printed materials organic, which is however, not always the case. Furthermore, the concept of injection molded structural electronics (IMSE) involves building functional devices and parts therefor in the form of a multilayer structure or assembly, which encapsulates electronic functionality as seamlessly as possible. Characteristic to IMSE is also that the electronics is commonly manufactured into a true 3D (non-planar) form in accordance with the 3D models of the overall target product, part or generally design. To achieve desired 3D layout of electronics on a 3D substrate and in the associated end product, the electronics may be still provided on an initially planar substrate, such as a film, using two dimensional (2D) methods of electronics assembly, whereupon the substrate, already accommodating the electronics, may be formed into a desired three-dimensional, i.e. 3D, shape and subjected to overmolding, for example, by suitable plastic material that covers and embeds the underlying elements such as electronics, thus protecting and potentially hiding the elements from the environment. Further layers and elements may be naturally added to the construction. In many cases, there have been difficulties in obtaining robust functional, integrated structures, or assembles, in which both mechanical and especially electrical connections, as well as other functionalities, operate reliably while still achieving cost-effective solutions. Typically, the connections are made by attaching the components and/or sub-assemblies to the substrate from below, that is, between the components and/or sub-assemblies and the substrate to which they are connected. The electrical connection means, such as connectors and/or pads or the like, used for connecting are arranged to be "under" the components and/or sub-assemblies which can result in a complex, laborious, and costly way of producing the assembly. JP2002158509A discloses a high frequency circuit module and a method for manufacturing the same, wherein the high frequency module comprises a semiconductor element flip-chip bonded via an electrode and a bump to a first signal line of a carrier substrate, which in turn is mounted on a main substrate and connected to the main substrate via a conductive connection portion. US2022013429A1 discloses a semiconductor device and a method for manufacturing a semiconductor device, wherein a semiconductor element on a submount is mounted on a package substrate using a joint member. SUMMARY The objective of the present invention is to at least alleviate one or more of the above drawbacks associated with the known solutions in the context of integral electronics assemblies including electronics modules or sub-assemblies, and especially connections thereof. The objectives of the invention are reached by a method for manufacturing an electronics assembly and an electronic assembly as defined by the resp