Substrate of circuit module and manufacturing method therefor

A high-frequency module including a high-frequency substrate having a coplanar line coupled with a coaxial connector, wherein said coplanar line further includes

• a first dielectric layer,
• a signal line that is formed on the surface of the first dielectric layer and connected to an inner conductor of the coaxial connector,
• a first ground that is formed in opposite areas beside the signal line with a clearance distant from the signal line, and
• a second ground that is formed on the backside of the first dielectric layer,
• wherein a second dielectric layer is laminated with the first dielectric layer so as to interpose the second ground therebetween, and
• wherein the second ground is exposed in a predetermined area of the first dielectric layer, so that the exposed portion of the second ground is connected to an outer conductor of the coaxial connector.

A manufacturing method of a high-frequency substrate including a coplanar line coupled with a coaxial connector, comprising:

• sequentially forming a second conductive layer, a first dielectric layer, and a first conductive layer on a second dielectric layer;
• selectively removing the first conductive layer and the first dielectric layer so as to expose a predetermined area of the second conductive layer;
• selectively removing the first conductive layer so as to form a signal line coupled with the coaxial connector on the first dielectric layer;
• and
• forming a ground on a terminal face coupled with the coaxial connector in opposite areas beside the signal line with a clearance distant from the signal line, thus forming the coplanar line including the signal line, the ground, and the second dielectric layer.

A manufacturing method of a high-frequency substrate including a coplanar line coupled with a coaxial connector, comprising:

• sequentially forming a second conductive layer, a first dielectric layer, and a first conductive layer on a second dielectric layer;
• selectively removing the second dielectric layer so as to expose the second conductive layer in opposite areas beside the signal line at a terminal face coupled with the coaxial connector;
• selectively removing the first conductive layer so as to form a signal line coupled with an inner conductor of the coaxial connector on the first dielectric layer;
• and
• forming a ground in the opposite areas beside the signal line with a clearance distant from the signal line, thus forming the coplanar line including the signal line, the second conductive layer, and the ground.