Flexible printed circuit (fpc) board

Abstract

A flexible printed circuit (FPC) board having reinforcing pattern against bending is disclosed. The FPC board provides an RF interconnection extending from an RF electrode. Two ground electrodes are formed in respective sides of the RF electrode. The ground electrodes extend respective extended portions along the RF interconnection to protect the RF interconnection from breakage due to bending of the FPC board. The extended portion provides an end portion bent toward the RF interconnection to compensate for impedance mismatching of the RF interconnection.

What is claimed is: 
     
         1 . A flexible printed circuit (FPC) board soldered to a rigid circuit board, comprising:
 a top electrode provided in a top surface of one end of the FPC board; and   a back electrode provided in a back surface of the one end of the FPC board, the back electrode being connected to the top electrode through a via hole and soldered to a pad provided in the rigid circuit board,   wherein at least one of the top electrode and the back electrode extends an interconnection and another of the top electrode and the back electrode extends an extended portion terminated in the one end of the FPC board.   
     
     
         2 . The FPC board of  claim 1 ,
 wherein the extended portion has a width substantially same with a width of the another of the top electrode and the back electrode.   
     
     
         3 . The FPC board of  claim 1 ,
 wherein the one end includes an extended region and an electrode region, the electrode region including the top electrode and the back electrode, and   wherein the extended portion of the another of the top electrode and the back electrode terminates in the extended region.   
     
     
         4 . The FPC board of  claim 3 ,
 further comprising an overlay for covering the extended portion in the extended region and exposing the electrode region.   
     
     
         5 . The FPC board of  claim 1 ,
 further comprising,   another top electrode provided in the top surface of the one end of the FPC board, and   another back electrode provided in the back surface of the one end of the FPC board, the another back electrode being connected to the another top electrode through a via hole and soldered to a pad provided in the rigid circuit board,   wherein one of the another top electrode and the another back electrode provided extends another interconnection in one of the top surface and the back surface opposite to a surface where the interconnection is provided, and   wherein another of the another top electrode and the another back electrode provided in the surface where the interconnection is provided extends another extended portion terminated in the one end of the FPC board.   
     
     
         6 . A flexible printed circuit (FPC) board connected to a rigid circuit board, comprising:
 a top RF electrode provided in one end of a top surface of the FPC board and a back RF electrode provided in the one end of a back surface of the FPC board, the top RF electrode extending an RF interconnection and being electrically connected to the back RF electrode through a via hole, the back RF electrode being soldered to the rigid circuit board; and   a top ground electrode provided in the one end of the top surface and a back ground electrode provided in the one end of the back surface electrically connected to the top ground electrode through a via hole, the top ground electrode being next to the top RF electrode and the back ground electrode being next to the back RF electrode, the back ground electrode being soldered to the rigid circuit board,   wherein the back ground electrode extends a ground pattern as forming a gap to the back RF electrode, and the top ground electrode extends an extended portion terminated in the one end of the FPC board.   
     
     
         7 . The FPC board of  claim 6 ,
 wherein the extended portion has a width substantially equal to a width of the top ground electrode.   
     
     
         8 . The FPC board of  claim 6 ,
 wherein the one end of the FPC board includes an extended region and an electrode region, the electrode region including the top RF electrode, the back RF electrode, the top ground electrode, and the back ground electrode, and   wherein the extended portion of the top ground electrode terminates in the extended region of the FPC board.   
     
     
         9 . The FPC board of  claim 8 ,
 further comprising an overlay for covering the extended portion of the top ground electrode and the RF interconnection in the extended region and exposing the electrode region.   
     
     
         10 . The FPC board of  claim 6 ,
 wherein the top ground electrode further includes an end portion extending from the extended portion and terminated in the one end of the FPC board, the end portion being bent toward the RF interconnection in a portion corresponding to the gap in the back surface.   
     
     
         11 . The FPC board of  claim 6 ,
 further comprising another top ground electrode and another back ground electrode electrically connected to the another top ground electrode through a via hole, the top ground electrode and the another top ground electrode sandwiching the top RF electrode, the back ground electrode and the another back ground electrode sandwiching the back RF ground,   wherein the back ground electrode, the ground pattern, and the another back ground electrode surround the back RF electrode with a gap.   
     
     
         12 . The FPC board of  claim 10 ,
 wherein the another top ground electrode provides an extended portion terminated in the one end of the FPC board.   
     
     
         13 . The FPC board of  claim 12 ,
 wherein the another top ground electrode further provides an end portion extending from the extended portion of the another top ground electrode, and   wherein the end portion of the another top ground electrode is bent toward the RF interconnection in a portion corresponding to the gap in the back surface.   
     
     
         14 . A flexible printed circuit (FPC) board soldered to a rigid circuit board, comprising:
 a plurality of RF interconnections each connected to respective top RF electrodes provided in one end of a top surface of the FPC board, the top RF electrodes being electrically connected to respective back RF electrodes provided in the one end of a back surface of the FPC board through via holes;   a plurality of top ground electrodes and a plurality of back ground electrodes each electrically connected to top ground electrodes corresponding thereto through respective via holes,   wherein the top RF electrodes and the top ground electrodes are arranged alternately, and the back RF electrodes and the back ground electrodes are alternately arranged,   wherein the back RF electrodes and the back ground electrodes are soldered to the rigid circuit board,   wherein the back ground electrodes are electrically connected through a ground pattern with gaps against the respective back RF electrodes, and   wherein the top ground electrodes each has an extended portion with a width substantially equal to widths of the top ground electrodes and terminated in the one end of the FPC board.   
     
     
         15 . The FPC board of  claim 14 ,
 wherein the top ground electrodes each includes an end portion extending from the extended portion, the end portion being bent toward the RF interconnection in a portion corresponding to the gap between the ground pattern and the back RF electrodes in the back surface of the FPC board.   
     
     
         16 . The FPC board of  claim 15 ,
 wherein the one end includes an electrode region and an extended region, the electrode region including the top RF electrodes, the top ground electrodes, the back RF electrodes, and the back ground electrodes, the extended region terminating the end portions of the top ground electrodes.   
     
     
         17 . The FPC board of  claim 16 ,
 further comprising an overlay for covering the RF interconnections and exposing the electrode region.