A disclosed circuit board includes an insulating core layer that has a first surface and a second surface opposing each other, an insulating auxiliary member of which at least a part is disposed in the insulating core layer and which has a coefficient of thermal expansion (CTE) different from that of the insulating core layer, a first substrate portion that includes a first insulating layer which is disposed on the first surface, and a first circuit wiring which is embedded in the first insulating layer, and a second substrate portion that includes a second insulating layer which is disposed on the second surface, and a second circuit wiring which is embedded in the second insulating layer.

A method of manufacturing an intermediate product for an interposer including a glass substrate having a plurality of through holes is provided. The method includes a step of forming a resin layer on a support substrate, and a step of forming a laminated body by adhering the glass substrate having the plurality of through holes on the resin layer. The glass substrate having the plurality of through holes has a thickness within a range of 0.05 mm to 0.3 mm.

A detecting unit is presented. The detecting unit includes a flexible circuit having a first side and a second side opposite the first side. The flexible circuit includes a plurality of cells defined therein, each of the plurality of cells having a first side and a second side respectively corresponding to the first side and the second side of the flexible circuit. Moreover, the flexible circuit includes a plurality of conductive windings disposed on at least one of the first and second sides of the plurality of cells. Further, the flexible circuit includes a stress reduction feature between each of the plurality of cells. Also, the detecting unit includes a sealing element configured to secure the flexible circuit in a stacked configuration. A sensing system and a method of making a detecting unit are also presented.

A method of manufacturing an intermediate product for an interposer including a glass substrate having a plurality of through holes is provided. The method includes a step of forming a resin layer on a support substrate, and a step of forming a laminated body by adhering the glass substrate having the plurality of through holes on the resin layer. The glass substrate having the plurality of through holes has a thickness within a range of 0.05 mm to 0.3 mm.

A method of manufacturing a circuit board includes: forming a plurality of metal electrodes so as to be separated from each other on a holding sheet by cutting a metal foil held on the holding sheet to remove a portion of the metal foil; forming adhesive layers on surfaces of the plurality of metal electrodes; adhering the adhesive layers to a base material by closely contacting the adhesive layers with the base material; and transcribing the adhesive layers and the plurality of metal electrodes onto the base material by detaching the holding sheet from the plurality of metal electrodes.