High-frequency line structure for impedance matching a microstrip line to a resin substrate and method of making

A method of manufacturing a high-frequency line structure, comprising:

• forming a multi-layered interconnection structure including:
• a multi-layered resin substrate in which a plurality of insulating layers of a resin are laminated;
• a high-frequency-signal input part including an input pad over a first surface of the resin substrate, a supply pad in the resin substrate facing the input pad, and a first via in a portion of the resin substrate located between the input pad and the supply pad and connected to the input pad and the supply pad;
• a high-frequency-signal output part including an output pad over the first surface of the resin substrate, a reception pad in the resin substrate facing the output pad, and a second via in a portion of the resin substrate located between the output pad and the reception pad, the second via being connected to the output pad and the reception pad;
• a first metal layer on the first surface of the resin substrate encircling the input pad and the output pad, the first metal layer electrically insulated from the high-frequency-signal input part and the high-frequency-signal output part;
• and a second metal layer on a second surface of the resin substrate opposite to the first surface of the resin substrate;
• forming a plurality of penetration vias which penetrate the first metal layer, the second metal layer, and the portion of the multi-layered resin substrate between the first metal layer and the second metal layer, after the multi-layered interconnection structure is formed;
• and
• forming a microstrip line on a top surface of the high-frequency line structure, the microstrip line comprising an insulation layer covering the top surface of the high-frequency line structure, a first wiring pattern formed on the insulation layer and connected to the input pad, and a second wiring pattern formed on the insulation layer and connected to the output pad;
• wherein the forming of the multi-layered interconnection structure includes:
• forming the high-frequency-signal input part further including:
• a first pad arranged on the first surface of the resin substrate and under the input pad and connected to one end of the first via;
• a second pad arranged in the resin substrate and over the supply pad to face the first pad, and connected to the other end of the first via;
• and
• a first conductor arranged in a portion of the resin substrate between the first pad and the second pad to face the first and second pads, connected to the first via, and provided for impedance matching;
• and
• forming the high-frequency-signal output part further including:
• a third pad arranged on the first surface of the resin substrate and under the output pad and connected to one end of the second via;
• a fourth pad arranged in the resin substrate and over the reception pad to face the third pad, and connected to the other end of the second via;
• and
• a second conductor arranged in a portion of the resin substrate between the third pad and the fourth pad to face the third and fourth pads, connected to the second via, and provided for impedance matching.