A method for producing a multilayer substrate (1) is specified, wherein a main body (26) comprising a plurality of ceramic layers (2) is provided, wherein at least one layer (2) comprises a hole (27). In order to form a plated-through hole (4, 18, 20, 21), the hole (27) is filled with a metal by depositing the metal from a solution. Furthermore, a multilayer substrate is specified wherein a plated-through hole (4, 18, 20, 21) in the interior of the main body (26) is connected to a further contact (11), wherein the plated-through hole (4, 18, 20, 21) comprises a different material than the further contact (11) and/or is produced by a different method.

macros hash =multilayer substrate star =plated-throuch hole pie =connection contact alpha =photoresist mask beta =further contact gamma =HTCC technology delta =main body matt =ceramic layer

A power module substrate with a Ag underlayer of the invention includes: a circuit layer that is formed on one surface of an insulating layer; and a Ag underlayer that is formed on the circuit layer, in which the Ag underlayer is composed of a glass layer that is formed on the circuit layer side and a Ag layer that is formed by lamination on the glass layer, and regarding the Ag underlayer, in a Raman spectrum obtained by a Raman spectroscopy with incident light made incident from a surface of the Ag layer on a side opposite to the glass layer, when a maximum value of intensity in a wavenumber range of 3,000 cm.sup.−1 to 4,000 cm.sup.−1 indicated by I.sub.A, and a maximum value of intensity in a wavenumber range of 450 cm.sup.−1 to 550 cm.sup.−1 is indicated by I.sub.B, I.sub.A/I.sub.B is 1.1 or greater.

The purpose of the present invention is to provide an electronic component in which a copper electrode and an inorganic substrate exhibit strong adhesion to each other. A method for producing an electronic component according to the present invention comprises: an application step wherein a paste is applied onto an inorganic substrate, which paste contains copper particles, copper oxide particles and/or nickel oxide particles, and inorganic oxide particles having a softening point: a sintering step wherein a sintered body which contains at least copper is formed by means of heating in an inert gas atmosphere at a temperature that is less than the softening point of the inorganic oxide particles but not less than the sintering temperature of the copper particles; and a softening step wherein hearing is carried out in an inert gas atmosphere at a temperature that is not less than the softening point of the inorganic oxide particles.

The present disclosure is intended to reduce connection resistance between a shield film and a ground electrode, and to improve characteristics of the shield film. A high frequency component 1a includes a ceramic substrate 2, a ground electrode 3a disposed inside the ceramic substrate 2, a shield film 4 covering an upper surface 2a and lateral surfaces 2c of the ceramic substrate 2, and connecting portions 6a connecting the ground electrode 3a and the shield film 4, wherein the ground electrode 3a is formed using a conductive paste that contains a metal ingredient, powder, and a material constituting the ceramic substrate 2, and a weight rate of a metal ingredient in the connecting portions 6a is higher than that of the metal ingredient in the ground electrode 3a.

The purpose of the present invention is to provide an electronic component in which a copper electrode and an inorganic substrate exhibit strong adhesion to each other. A method for producing an electronic component according to the present invention comprises: an application step wherein a paste is applied onto an inorganic substrate, which paste contains copper particles, copper oxide particles and/or nickel oxide particles, and inorganic oxide particles having a softening point; a sintering step wherein a sintered body which contains at least copper is formed by means of heating in an inert gas atmosphere at a temperature that is less than the softening point of the inorganic oxide particles but not less than the sintering temperature of the copper particles; and a softening step wherein heating is carried out in an inert gas atmosphere at a temperature that is not less than the softening point of the inorganic oxide particles.

The present disclosure is intended to reduce connection resistance between a shield film and a ground electrode, and to improve characteristics of the shield film. A high frequency component 1a includes a ceramic substrate 2, a ground electrode 3a disposed inside the ceramic substrate 2, a shield film 4 covering an upper surface 2a and lateral surfaces 2c of the ceramic substrate 2, and connecting portions 6a connecting the ground electrode 3a and the shield film 4, wherein the ground electrode 3a is formed using a conductive paste that contains a metal ingredient, powder, and a material constituting the ceramic substrate 2, and a weight rate of a metal ingredient in the connecting portions 6a is higher than that of the metal ingredient in the ground electrode 3a.

A power module substrate with a Ag underlayer of the invention includes: a circuit layer that is formed on one surface of an insulating layer; and a Ag underlayer that is formed on the circuit layer, in which the Ag underlayer is composed of a glass layer that is formed on the circuit layer side and a Ag layer that is formed by lamination on the glass layer, and regarding the Ag underlayer, in a Raman spectrum obtained by a Raman spectroscopy with incident light made incident from a surface of the Ag layer on a side opposite to the glass layer, when a maximum value of intensity in a wavenumber range of 3,000 cm.sup.1 to 4,000 cm.sup.1 indicated by I.sub.A, and a maximum value of intensity in a wavenumber range of 450 cm.sup.1 to 550 cm.sup.1 is indicated by I.sub.B, I.sub.A/I.sub.B is 1.1 or greater.

A power module substrate includes an insulating layer, a circuit layer that is formed on a first surface of the insulating layer, and a metal layer that is formed on a second surface of the insulating layer, in which a first base layer is laminated on a surface of the metal layer on the opposite side of the surface to which the insulating layer is provided, and the first base layer has: a first glass layer that is formed at the interface with the metal layer; and a first Ag layer that is laminated on the first glass layer.