Double-sided wiring board fabrication method, double-sided wiring board, and base material therefor

A method for fabricating a double-sided wiring board for mounting an electronic component thereon comprising metal wiring patterns formed both on upper and lower sides of an electrically-insulating board, the metal wiring patterns being electrically connected each other through a through-hole and/or a blind via-hole, comprising the steps of:

• laminating a metal layer with a support substrate on at least one side of the electrically-insulating board;
• forming the through-holes and/or the blind via-holes in the electrically-insulating board;
• and
• removing the support substrate from the metal layer so that the metal layer is left on the electrically-insulating board.

A method for fabricating a double-sided wiring board for mounting electronic components thereon comprising metal wiring patterns formed both on upper and lower sides of an electrically-insulating board, the metal patterns being electrically connected each other through a blind via-hole, comprising the steps of:

• laminating a metal layer with a support substrate on both sides of the electrically-insulating board;
• removing the support substrate located on an open side of the blind via-hole and subsequently forming the blind via-hole in the electrically-insulating board, or forming the blind via-hole in the electrically-insulating board and subsequently removing the support substrate located on the open side of the blind via-holes;
• and
• making the electrical connection on a wall of the blind via-hole and subsequently removing the support substrate located on opposite the open side of the blind via-hole.

A double-sidedwiring board for mounting an electronic component, comprising:

• an electrically-insulating board;
• metal wiring patterns formed both on upper and lower sides of the electrically-insulating board;
• and
• a through-hole and/or a blind via-hole formed in the electrically-insulating board for allowing electrical conduction between the metal wiring patterns therethrough, wherein:
• the metal wiring patterns comprising a first metal layer,
• the through-hole and/or a blind via-hole comprises a second metal layer formed on a wall thereof, and
• the first metal layer comprises a thickness 1 to 8 μm greater than the second metal layer.

A base material for fabricating a double-sided wiring board for mounting an electronic component, comprising:

• an electrically-insulating board;
• metal wiring patterns formed both on upper and lower sides of the electrically-insulating board;
• and
• a through-hole and/or a blind via-hole formed in the electrically-insulating board for allowing electrical conduction between the metal wiring patterns therethrough, wherein:
• a metal layer with a support substrate is laminated on at least one side of the electrically-insulating board.