Provided is a mother ceramic substrate that, when divided into individual substrates (ceramic substrates), can be divided to cause divided end surfaces to be perpendicular to principal surfaces of the individual substrates, and that can provide ceramic substrates with high form accuracy; an individual ceramic substrate obtained from the mother ceramic substrate; a module component including the ceramic substrate; and a method of manufacturing a mother ceramic substrate. In a mother ceramic substrate that can be divided at a predetermined position and separated into a plurality of individual substrates, a dividing groove that defines a division position is formed in a principal surface on one side, and a protruding thread is formed on a principal surface on another side at a position corresponding to a position of the dividing groove formed in the principal surface on the one side in view in a thickness direction of the mother ceramic substrate.

The present invention focuses on a silicon nitride substrate having high mechanical strength, high thermal conductivity and the like, and takes advantage of such properties to provide: a ceramic substrate capable of providing improvement in a bonding property between a silicon nitride substrate and a ceramic layer which uses a dielectric ceramic material capable of being simultaneously sintered with a low-resistance conductive material such as a low-melting metal (Ag or Cu); and a method for producing the ceramic substrate. The ceramic substrate of the present invention is obtained by stacking and bonding a silicon nitride substrate and a ceramic layer composed of a dielectric ceramic material, wherein: the dielectric ceramic material contains Mg, Al, and Si as main ingredients, and Bi or B as an accessory ingredient; and the ceramic layer includes a region with a high Si element concentration at a bonding interface with the silicon nitride substrate.

A printed circuit board according to an embodiment of the present invention includes a base film having an insulating property and a conductive pattern disposed on at least one surface of the base film. The conductive pattern includes a copper particle bond layer which is fixed to the base film, and a lightness L* of a conductive pattern non-formed region of the base film is 60 or less. The base film may include a modified layer on one surface side thereof.

A method of manufacturing a circuit substrate includes the steps of preparing a conductor paste in which a powder of at least one of a metal boride and a metal silicide is added to a powder of silver (Ag), applying the conductor paste to a surface of a ceramic substrate which has been fired, applying a glass paste to the surface of the ceramic substrate after applying the conductor paste, firing the conductor paste applied to the surface so as to form a conductor trace, and firing the glass paste applied to the surface so as to form a coating layer.

A ceramic-copper composite having a flat plate shape, including: a ceramic layer; a copper layer; and a brazing material layer present between the ceramic layer and the copper layer, in which a specified Expression (1) is satisfied in a cut surface of the copper layer obtained when the ceramic-copper composite is cut at a plane perpendicular to a main surface of the ceramic-copper composite, where S(102)% is an area ratio occupied by copper crystals having a crystal orientation of which an inclination from a crystal orientation of (102) plane is within 10?, S(101)% is an area ratio occupied by copper crystals having a crystal orientation of which an inclination from a crystal orientation of (101) plane is within 10?, S(111)% is an area ratio occupied by copper crystals having a crystal orientation of which an inclination from a crystal orientation of (111) plane is within 10?, and S(112)% is an area ratio occupied by copper crystals having a crystal orientation of which an inclination from a crystal orientation of (112) plane is within 10?.

A method for forming track(s) on low temperature co-fired ceramic (LTCC) substrate, the method comprising the steps of, forming a layer of coating material on an operative face of the LTCC substrate, disposing a stencil on the layer of coating material thereby covering a selected portion of the layer of coating material while leaving exposed a portion of the layer of coating material corresponding to the track(s) to be formed and forming an assembly of the LTCC substrate, the layer of coating material and the stencil, eroding the exposed portion of the layer of coating material by propelling an abrasive material using a blasting gun towards the assembly on the face on which the layer of coating material is formed and the stencil is disposed and separating the stencil from the abraded assembly, wherein the abrasive material has a composition that is compatible with that of the LTCC substrate.

A stretchable circuit board includes plural stretchable bases, and plural stretchable wiring portions, at least one of which is provided on each of main surfaces, facing each other, of the plural stretchable bases, in which the stretchable wiring portions provided on the main surfaces are electrically continuous with each other through a connecting portion.

A photosensitive glass paste contains a photosensitive organic component and an inorganic component containing a glass powder having a high softening point, a glass powder having a low softening point, and a ceramic filler. The ceramic filler has a thermal expansion coefficient of 1010.sup.6/ C. to 1610.sup.6/ C., the inorganic component contains 30% to 50% by volume of the ceramic filler, and the inorganic component contains 0.5% to 10% by volume of the glass powder having a low softening point.

A conductive paste contains at least a conductive powder, glass frit, and an organic vehicle. The conductive powder is a mixed powder of an atomized powder prepared by an atomization method and a wet reduced powder prepared by a wet reduction method and the conductive powder contains the atomized powder in the range of 5 to 40 wt %. The atomized powder is 5.2 to 9 m in average particle size and the content of a chlorine component mixed in the conductive powder is 42 ppm or less. The conductive paste is applied in the form of a line onto a glass substrate 1 and subjected to firing to form conductive films. This conductive paste can prevent glass substrates from undergoing color changes and prevent base layers for conductive films from having structural defects such as cracks.

A substrate (1, 10) for electrical circuits, comprising at least one metal layer (2,3, 14) and a paper ceramic layer (11), which is joined face to face with the at least one metal layer (2,3, 14) and has a top side and bottom side (11a, 11b), wherein the paper ceramic layer (11) has a large number of cavities in the form of pores. Especially advantageously, the at least one metal layer (2, 3, 14) is connected to the paper ceramic layer (11) by means of at least one glue layer (6, 6a, 6b), which is produced by applying at least one glue (6a, 6a, 6b, 6b) to the metal layer (2,3, 14) and/or to the paper ceramic layer (11), wherein the cavities in the form of pores in the paper ceramic layer (11) are filled at least at the surface by means of the applied glue (6a, 6a, 6b,6b).