JP-2022531153-A5 -

Dates

Publication Date

20230501

Application Date

20200422

Description

A new 3D printing technique that overcomes most of the material-related problems mentioned above is the use of laser direct writing (LDW) techniques. In this technique, a laser beam is used to create patterned surfaces with spatially resolved three-dimensional structures through controlled ablation or deposition of material. Laser-induced forward transfer (LIFT) is one LDW technique that can be applied when depositing micropatterns onto a surface. In LIFT, laser photons provide the driving force to eject a small amount of material from a donor film toward an acceptor substrate. Typically, the laser beam interacts with the inside of the donor film coated on a non-absorbent carrier substrate. In other words, the incident laser beam propagates through the transparent carrier substrate, and then the photons are absorbed by the inner surface of the film. Once a certain energy threshold is exceeded, the material is emitted from the donor film toward the surface of the substrate. LIFT-based printing systems are described, for example, in U.S. Publication No. 2005/0212888, U.S. Publication No. 2009/007498, and International Publication No. 2016/020817. Furthermore, International Publication 2018/216002 by Zenou et al. describes a method for manufacturing an electronic device. In this method, a die containing an electronic component with integrated contacts is fixed to a dielectric substrate. After fixing the die, conductive traces are printed on both the dielectric substrate and at least one integrated contact to create an ohmic connection between the conductive traces on the substrate and the electronic component. Using a LIFT process (Figure (ii)), liquid support material 18 is applied to the PCB 10 in the region where an electronic connection will subsequently be formed between the PCB connector and the connector of the electronic component. As shown in the figure, this is often within the gap between the edge of the electronic component 12 and the connector 14 of the PCB 10. The support material 18 must be applied in an amount sufficient to fully support the subsequent electronic connection. As shown in Figures (ii)–(vii), this can mean applying multiple layers 18, 22, 26 of the liquid support material (Figures (ii), (iv), (vi)) in a stacked manner, with a curing step (Figures (iii), (v), (viii)) following the application of each layer. Curing can be performed using UV illumination and optionally with heat (e.g., by an IR lamp, heater, or similar device) to form solidified (or at least partially solidified) support layers 20, 24, 28. The completed solid support structure, composed of layers 20 , 24, and 28 of support material, will provide a fully supported path for electrical connections between the connectors of the electronic components and the connectors of the PCB. As shown in Figures 6C and 6D, the same procedure can be used multiple times to create very complex structures with multiple wires. For example, the above process of creating a support structure and then printing a layer of conductive material on it can be applied in a multi-step procedure to electrically connect the additional connectors 14' of the electrical component(s) 12 and PCB 10. In the illustrated example, the second set of connectors 14' of the electrical component(s) 12 and PCB 10 are electrically connected by a second set of conductors 62 printed on a second support structure 60 which is applied covering the top of the conductive layer 58. The second support structure 60 can be applied in the same way as the support structure 52 described above (e.g., using LIFTs) to create one or more layers of support material , and the conductive elements 62 can be printed on the second support structure 60 in the same way as the conductive elements 58. If necessary, the second support structure and the second conductive elements can be constructed for the entire electrical component 12 or only a part thereof. Naturally, in order to complete the electrical connection between the electrical component(s) 12 and the PCB 10 as needed, further support structures and conductive elements can be constructed in the manner described above.