US 7,405,146 B2Granted

Electroplating method by transmitting electric current from a ball side

AssigneeKinsus Interconnect Technology Corp.

InventorCheng-Kuo Ma

Life of this patent

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Abstract

An electroplating method by transmitting electric current from a ball side is provided. In the electroplating method, the circuit layer is firstly formed on the bump side of the IC board, and the electric current is transmitted to the portion of the circuit layer uncovered by the insulating layer formed on the bump side from the electroplated metal layer on the ball side to form the protective layer (the electroplated gold layer) on the portion of the circuit layer. In such a way, the electroplated gold layer cannot be formed under the insulating layer formed on the bump side (attached with the chip) because the electroplated gold layer is formed after the insulating layer has been formed, and thereby the fall-off of the insulating layer from the electroplated gold layer will not happen. Therefore, the reliability of the products is enhanced.

Claims7

Dependent claims

An electroplating method by transmitting an electric current from a ball side, comprising the steps of:

providing an IC board having a bump side and a ball side, and a through hole being formed therein, an electroplated metal layer being formed on the bump side, the ball side, and a wall of the through hole, wherein the bump side, and the ball side are electrically connected to each other via the electroplated metal layer;
patterning the electroplated metal layer formed on the bump side to form a first circuit layer, wherein the first circuit layer, and the electroplated metal layer formed on the ball side of the IC board are electrically connected to each other;
forming an insulating layer on the bump side to expose a portion of a top of the first circuit layer;
and
forming a first protective layer on the exposed portion of the top of the first circuit layer by transmitting an electric current from the electroplated metal layer formed on the ball side to the first circuit layer formed on the bump side.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/338,376Filed 24 Jan 2006
Published: US 2007/0173052 A126 Jul 2007
Granted: 29 Jul 2008
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

H05K 3/243
Reinforcing of the conductive pattern: characterised by selective plating, e.g. for finish plating of pads
H05K 3/062
Etching masks: consisting of metals or alloys or metallic inorganic compounds
H05K 3/242
Characterised by the electroplating method; means therefor, e.g. baths or apparatus: characterised by using temporary conductors on the printed…
H05K 3/28
Secondary treatment of printed circuits: applying non-metallic protective coatings