Examples are disclosed related to forming solder joints between printed circuits by using radiant heat. One example provides a method of manufacturing an electronic device, the method comprising aligning a contact of a first printed circuit with a via of a second printed circuit. The method further comprises applying radiant heat via an infrared light source to a second surface of the second printed circuit, the radiant heat incident on the via to cause the via to conduct heat to solder located at an interface of the contact and the via, and after heating the solder to reflow, cooling the solder, thereby forming a solder joint between the contact of the first printed circuit and the via of the second printed circuit.

An intermediate connection layer interposed between a wiring substrate and an electronic part includes a rigid substrate and a flexible substrate. A plurality of conductor portions are formed on opposed principal surfaces of the respective flexible and rigid substrates. The rigid substrate is provided with an opening, and a fuse portion on the flexible substrate faces the opening. The flexible substrate and the rigid substrate are bonded together with solders. The respective rigid and flexible substrates are separately made, solder pastes are applied to the rigid substrate, both substrates are overlaid on each other, and the solder pastes are heated and solidified to make the intermediate connection layer.

There is provided a flexible printed circuit board. The flexible printed circuit board includes: a flexible insulation layer having a first surface and a second surface; a first land which is conductive and which is provided on the first surface of the flexible insulation layer; and a conductive member which is provided on the second surface of the flexible insulation layer. A recess is formed on the first land.

An electronic module has a flexible wiring member, a wiring circuit board, and a conductive connection member. The flexible wiring member has a flexible base, a first wiring layer formed on at least one face of the flexible base, and a first electrode formed of the first wiring layer at the end part that is not covered by a first insulating layer. The wiring circuit board has a base provided with a wiring, a second insulating layer having opening formed on at least one face of the base, and a second electrode formed in the opening. The conductive connection member connects the first electrode and the second electrode to each other. The end of the flexible wiring member is arranged above the opening in plan view.

Disclosed is a system for mounting a flexible first substrate having a first connection region provided with a first electrode group, on a second substrate having a second connection region provided with a second electrode group. The system includes: a stage configured to support the second substrate; a unit for supplying a bonding material including conductive particles and a thermosetting resin, to at least one of the first and second electrode groups; a unit for placing the first substrate on the second substrate via the bonding material and a unit for successively performing a joining process by pressing a first electrode toward a second electrode and curing the thermosetting resin, using a heating tool, while moving the tool to a processing position of another first electrode not yet subjected to the joining process.

Provided is a wiring board including a substrate formed of an insulation material, and plural conductive patterns including plural electrodes arranged on a surface of the substrate along an end surface of the substrate, and plural wiring patterns connected to the plural electrodes, respectively, wherein the substrate includes a notch formed between electrode groups each of which includes a predetermined number of the electrodes.

A fingerprint sensor package includes a substrate, a fingerprint sensor chip, and a flexible printed circuit board (FPC). The substrate includes a first portion and a second portion. A line layer is disposed on the first portion. The fingerprint sensor chip is disposed on the substrate. The fingerprint sensor chip is electrically connected to the FPC by the line layer. The package is simple, reliable, and easy for manufacturing process, reducing materials and processing costs.

A flexible substrate has an insulating base member and a conductive layer that is formed on the base member and includes an electrical connecting portion fixed to a component and electrically connected to the component, and the flexible substrate includes: a main portion on which the electrical connecting portion is formed; and a protruding portion provided so as to protrude from a portion of the main portion in which the electrical connecting portion is formed, wherein the main portion is bent along a first bending line extending in a first direction, and wherein the protruding portion can be bent along a second bending line extending in a second direction intersecting the first direction and is adapted to reduce stress occurring at the electrical connecting portion by the protruding portion being bent along the second bending line.

A flexible light emitting diode (LED) circuit having a first layer, the first layer including a conductive material configured to connect to an LED die, a second layer, the second layer including an electrically insulating material, and a third layer positioned between the first and second layer, the third layer having a first terminal extended electrically connecting tab that extends outward beyond the first layer and the second layer.

Embodiments of the invention include LED lighting systems and methods. For example, in some embodiments, an LED lighting system is included. The LED lighting system can include a flexible layered circuit structure that can include a top thermally conductive layer, a middle electrically insulating layer, a bottom thermally conductive layer, and a plurality of light emitting diodes mounted on the top layer. The LED lighting system can further include a housing substrate and a mounting structure. The mounting structure can be configured to suspend the layered circuit structure above the housing substrate with an air gap disposed in between the bottom thermally conductive layer of the flexible layered circuit structure and the housing substrate. The distance between the layered circuit structure and the support layer can be at least about 0.5 mm. Other embodiments are also included herein.