A circuit board includes: a ceramic substrate that has a first surface and a second surface; a first metal part that has a first metal plate joined to the first surface and a protrusion projecting from a front surface of the first metal plate; and a second metal part that has a second metal plate joined to the second surface. When the ceramic substrate is equally divided into first to third sections along a longer side direction, V.sub.1, V.sub.2, V.sub.3, V.sub.4, V.sub.5, and V.sub.6 are numbers satisfying formula V.sub.4/V.sub.1+V.sub.6/V.sub.32(V.sub.5/V.sub.2), 0.5V.sub.4/V.sub.12, 0.5V.sub.5/V.sub.22, and 0.5V.sub.6/V.sub.32.

A piezochromic stamp is provided, wherein when a pressing side of the piezochromic stamp is subjected to a pressure, a light transmittance effect of the pressing side is changed from allowing a light having a specific wavelength to pass through to blocking the light having the specific wavelength, or the light transmittance effect of the pressing side is changed from blocking the light having the specific wavelength to allowing the light having the specific wavelength to pass through.

An object is to provide, for example, a method for manufacturing a film-forming substrate that can sufficiently improve both bleeding of a resin composition and adhesion between the resin composition and a metal substrate surface. For example, provided is a method for manufacturing a film-forming substrate having a film of a resin composition formed on a metal substrate surface, the method including: an etching step of etching a metal substrate surface with a micro-etching agent; a surface treatment step of bringing the etched metal substrate surface into contact with a surface treatment agent to perform a surface treatment such that a contact angle of water on the surface is 50 or more and 150 or less; and a film forming step of forming a film of a resin composition on the surface-treated metal substrate surface by an inkjet method.

A circuit pattern is obtained, capable of being easily applicable to current increase, making short circuit or ion migration between adjacent circuit conductors hard to be generated, and allowing a circuit pattern to be tightly arranged. A circuit pattern comprises a circuit conductor to be layered on a metal substrate through an insulating layer, an intermediate portion in a layer direction having a swelled shape in a layer-crossing direction in a cross section of the circuit conductor, and the swelled shape is formed by a gentle face in the layer direction.

A method of establishing conductive connections is disclosed. The method includes providing an integrated circuit die having a plurality of solder balls each of which has an oxide layer on an outer surface of the solder ball. The method also includes performing a heating process to heat at least the solder balls and applying a force causing each of a plurality of piercing bond structures on a substrate to pierce one of the solder balls and its associated oxide layer to thereby establish a conductive connection between the solder ball and the piercing bond structure.

A manufacturing method of a circuit board and a stamp are provided. The method includes the following steps. A circuit pattern and a dielectric layer covering the circuit pattern are formed on a dielectric substrate. A conductive via connected to the circuit pattern is formed in the dielectric layer. A photoresist material layer is formed on the dielectric layer. An imprinting process is performed on the photoresist material layer using a stamp to form a patterned photoresist layer, wherein the pressing side of the stamp facing the circuit pattern becomes sticky when subjected to pressure so as to catch photoresist residue from the photoresist material layer in the imprinting process. A patterned metal layer is formed on a region exposed by the patterned photoresist layer. The patterned photoresist layer is removed.

A printed wiring board includes a first conductor layer, a resin insulating layer having an opening, a second conductor layer including a seed layer and an electrolytic plating layer formed on the seed layer, and a via conductor including the seed layer and the electrolytic plating layer and connecting the first conductor and second conductor layers. The seed layer has a first portion on the surface of the insulating layer, a second portion on an inner wall surface in the opening of the insulating layer, and a third portion on a portion of the first conductor layer exposed by the opening of the insulating layer such that the first portion is thicker than the second portion and the third portion, the second portion has a first film and a second film electrically connected to the first film, and a portion of the first film is formed on the second film.

An etching method for manufacturing a substrate structure having a thick electrically conductive layer, and a substrate structure having a thick electrically conductive layer are provided. The etching method includes providing an electrically insulating substrate structure including a thermally conductive and electrically insulating layer, an electrically conductive layer, and a non-photosensitive polymer masking layer, removing one part of the non-photosensitive polymer masking layer and one part of the electrically conductive layer by a machining process to form at least one electrically conductive recess having the electrically conductive layer exposed, forming a predetermined thickness ratio between a thickness of the electrically conductive recess and a thickness of the electrically conductive layer, removing a reserved part of the electrically conductive layer between a bottom wall of the electrically conductive recess and a bottom surface of the electrically conductive layer, and removing a remaining part of the non-photosensitive polymer masking layer.

A manufacturing method of a circuit board and a stamp are provided. The method includes: forming a circuit pattern and a dielectric layer on a dielectric substrate; forming a conductive via in the dielectric layer; forming a thermal-sensitive adhesive layer on the dielectric layer; forming a photoresist material layer on the thermal-sensitive adhesive layer; imprinting the photoresist material layer using a stamp, wherein a first conductive layer is disposed on the surface of the pressing side of the stamp, a second conductive layer is disposed on the surface of the other portions; applying a current to the stamp; removing the stamp and the photoresist material layer and the thermal-sensitive adhesive layer below the pressing side to form a patterned photoresist layer and thermal-sensitive adhesive layer; forming a patterned metal layer on the region exposed by the patterned photoresist layer; removing the patterned photoresist layer and thermal-sensitive adhesive layer.

A manufacturing method of a circuit board including the following steps is provided. A carrier substrate is provided. A patterned photoresist layer is formed on the carrier substrate. An adhesive layer is formed on the top surface of the patterned photoresist layer. A dielectric substrate is provided. A circuit pattern and a dielectric layer covering the circuit pattern are formed on the dielectric substrate, wherein the dielectric layer has an opening exposing a portion of the circuit pattern. The adhesive layer is adhered to the dielectric layer in a direction that the adhesive layer faces of the dielectric layer. The carrier substrate is removed. A patterned metal layer is formed on a region exposed by the patterned photoresist layer. The patterned photoresist layer is removed. The adhesive layer is removed.