Microcapsule, sheet material, circuit board, method for manufacturing circuit board, and computer readable storage medium

A thermally expandable material comprising:

• a plurality of microcapsules;
• and
• a binder having an insulating property,
• wherein:
• each of the plurality of microcapsules includes (i) a shell including a conducting component and (ii) a thermally expandable component contained in the shell and having a property of expanding by heating,
• the shell is deformable in accordance with expansion of the thermally expandable component when the thermally expandable component is heated, and
• wherein two of the plurality of microcapsules enter into a conducting state with each other when the two of the plurality of microcapsules come into contact with each other due to expansion of their respective thermally expandable components by heating.

A sheet material comprising:

• a base layer;
• and
• a thermally expandable layer disposed on the base layer, the thermally expandable layer including a plurality of microcapsules and a binder having an insulating property,
• wherein:
• each of the plurality of microcapsules includes (i) a shell including a conducting component and (ii) a thermally expandable component contained in the shell and having a property of expanding by heating, and
• the shell of a first microcapsule of the plurality of microcapsules is deformable in accordance with expansion of the thermally expandable component of the first microcapsule by heating so as to come into contact with the shell of a second microcapsule of the plurality of microcapsules.

A circuit board comprising:

• a base layer;
• and
• a thermally expandable layer disposed on the base layer, the thermally expandable layer having a not- expanding region and an expanding region, the not-expanding region defining an insulating region of a circuit, the expanding region defining a conducting region of the circuit, and the thermally expandable layer including a plurality of microcapsules and a binder having an insulating property,
• wherein:
• each of the plurality of microcapsules includes (i) a shell including a conducting component and (ii) a thermally expandable component contained in the shell and having a property of expanding by heating, and
• the shell of a first microcapsule in the expanding region, from among the plurality of microcapsules, is deformable in accordance with expansion of the thermally expandable component of the first microcapsule by heating so as to come into contact with the shell of a second microcapsule of the plurality of microcapsules.

A method for manufacturing a circuit board, the method comprising:

• preparing a sheet material including a base layer and a thermally expandable layer disposed on the base layer;
• and
• partially expanding the sheet material so that a not-expanding region of the thermally expandable layer defines an insulating region of a circuit and an expanding region of the thermally expandable layer defines a conducting region of the circuit,
• wherein:
• the thermally expandable layer includes a plurality of microcapsules and a binder having an insulating property,
• each of the plurality of microcapsules includes (i) a shell including a conducting component and (ii) a thermally expandable component contained in the shell and having a property of expanding by heating, and
• in the partially expanding the sheet material, the shell of a first microcapsule in the expanding region, from among the plurality of microcapsules, deforms in accordance with expansion of the thermally expandable component by heating so as to come into contact with the shell of a second microcapsule of the plurality of microcapsules.

A non-transitory computer readable storage medium having stored thereon a program that is executable by a computer to cause the computer to implement functions for forming a circuit board of an electronic circuit, the functions comprising:

• setting a resistance value of a resistance included in electronic circuit diagram data of the electronic circuit;
• after the setting the resistance value, converting the electronic circuit diagram data to a conversion diagram used to form an image of at least a part of wiring included in the electronic circuit diagram data;
• and
• forming the image with photothermal ink on a thermally expandable layer included in a sheet material, based on the conversion diagram,
• wherein the circuit board is formed by expanding areas of the thermally expandable layer on which the image has been formed by heat generated by the photothermal ink.