Method of manufacturing electronic board, composite sheet, and electronic board

• Main Authors: Tadashi Kosuga, Tin-Lup Wong
• Format: Patent
• Language: English
• Published: 17.06.2020
• Subjects: CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; PERFORMING OPERATIONS; SOLDERING OR UNSOLDERING; TRANSPORTING; WELDING; WORKING BY LASER BEAM

A method of manufacturing an electronic board comprising, preparing a composite sheet having composite layer with a solder part and a resin part, placing the layer on a substrate, placing a first electronic component on the composite layer and heating the solder part up to a temperature at which the solder part is melted within the reflow furnace. The board may include a second component previously mounted on the substrate by reflow soldering before placing the composite layer where the melting point of the solder affixing the second component tis higher than that solder within the composite layer. The resin may be shaped to cover position on the substrate corresponding to at least four corners of the first electronic component. The resin may have a gap in portions other than the positions other than said corner portions. The composite sheet may comprise multiple composite layers. Also included are claims to a composite sheet comprising a composite layer with resin and solder parts where the solder may be exposed on the top and bottom surfaces of the layer and also a claim to an electronic board comprising a substrate with a first and second component mounted via reflow soldering and an underfill between the first component.