Cable plug assembly with internal circuit board

1. A cable plug assembly comprising:

a cable having a plurality of signal lines;

a plug portion connectable to a connection target;

a circuit board, a first end portion of the circuit board being provided with a plurality of connection portions that are respectively connectable by soldering to the signal lines of the cable, and a second end portion of the circuit board being connectable to the plug portion; and

a holder for removably holding the circuit board, the holder including a holder main body of a substantially U-shape in plan view, wherein

the holder main body has a pair of board holding portions and a signal line holding portion, the signal line holding portion being interposed between first lengthwise end portions of the pair of board holding portions, the holder main body further has a placing portion, the placing portion extending from the signal line holding portion in an opposite direction of the pair of board holding portions,

inner surfaces of the pair of board holding portions are provided with a pair of board guide grooves for movably guiding opposite widthwise end portions of the circuit board toward the signal line holding portion,

the signal line holding portion faces said first end portion of the circuit board when guided by the board guide grooves, and the signal line holding portion is provided with a plurality of signal line guide grooves for positioning and fixing the signal lines with respect to the connection portions of the circuit board, and

the placing portion is provided with an adhesive adhering to the placing portion and the plurality of signal lines which allows the signal lines, guided by the signal line guide grooves, to be adhered to the placing portion.

2. The cable plug assembly according to claim 1 , wherein the connection portions comprise pads arranged in a line on the circuit board.

3. The cable plug assembly according to claim 1 , further comprising:

shielding means for covering all around a rear end portion of the plug portion, the circuit board, and the holder, excluding a front end portion of the plug portion and an area for leading out the cable, the shielding means being adapted to restrict movement of the plug portion, the circuit board, and the holder.

4. A cable plug assembly comprising:

a cable having a plurality of signal lines;

a plug portion connectable to a connection target;

a circuit board, a first end portion of the circuit board being provided with a plurality of connection portions that are respectively connectable by soldering to the signal lines of the cable, and a second end portion of the circuit board being connectable to the plug portion; and

a holder for removably holding the circuit board, wherein

the holder has a holder main body of a substantially U-shape in plan view and a substantially inverted U-shaped engaging portion opening downward, the holder main body has a pair of board holding portions and a signal line holding portion, the signal line holding portion being interposed between first lengthwise end portions of the pair of board holding portions, the signal line holding portion has a plurality of signal line guide grooves for positioning and fixing the signal lines with respect to the connection portions of the circuit board, and inner surfaces of the pair of board holding portions are provided with a pair of board guide grooves for movably guiding opposite widthwise end portions of the circuit board toward the signal line holding portion; and

the plug portion has an engaging projection or an engaging recess, and

the engaging portion is oriented at a substantially right angle to second lengthwise end portions of the pair of board holding portions of the holder main body and has an engaging recess or an engaging projection for engagement with the engaging projection or the engaging recess of the plug portion with the circuit board being fitted in the board guide grooves of the pair of board holding portions.

5. The cable plug assembly according to claim 4 , further comprising:

shielding means for covering all around a rear end portion of the plug portion, the circuit board, and the holder,

excluding a front end portion of the plug portion and an area for leading out the cable, the shielding means being adapted to restrict movement of the plug portion, the circuit board, and the holder.

6. The cable plug assembly according to claim 5 , wherein the engaging portion has:

a pair of column portions respectively provided on first widthwise end surfaces of the pair of board holding portions of the holder main body; and

a beam portion suspended across the column portions, the shielding means has:

a first shield plate that is in contact with second widthwise end surfaces of the pair of board holding portions of the holder main body;

a second shield plate that is in contact with the beam portion of the engaging portion and faces the first shield plate with the circuit board and the holder therebetween;

a substantially U-shaped third shield plate that is in contact with first widthwise ends of the first and second shield plates and is also in contact with one of the board holding portions of the holder main body and one of the column portions of the engaging portion;

a substantially U-shaped fourth shield plate that is in contact with second widthwise ends of the first and second shield plates and is also in contact with other one of the board holding portions of the holder main body and other one of the column portions of the engaging portion; and

a holding shield member of a rectangular cylindrical shape with a bottom portion, the holding shield member being configured to cover and hold first lengthwise end portions of the first, second, third, and fourth shield plates and to contact with a first lengthwise end portion of the holder,

wherein the front end portion of the plug portion is exposed from space formed by the second lengthwise end portions of the first, second, third, and fourth shield plates, and

wherein the bottom portion of the holding shield member has a leading-out portion for leading out the cable.

7. The cable plug assembly according to claim 6 , wherein the holding shield member has:

a rectangular cylindrical box portion for covering the first lengthwise end portions of the first, second, third, and fourth shield plates; and

four closing plates that are bent at a substantially right angle from four sides of a first lengthwise end of the box portion in such a manner to form the bottom portion of the holding shield member, and

space formed among top portions of the four closing plates serves as the leading-out portion.

8. A cable plug assembly comprising:

a cable having a plurality of signal lines;

a plug portion connectable to a connection target;

a circuit board, a first end portion of the circuit board being provided with a plurality of connection portions that are respectively connectable by soldering to the signal lines of the cable, and a second end portion of the circuit board being connectable to the plug portion; and

a holder for removably holding the circuit board, wherein

the holder has a holder main body of a substantially U-shape in plan view and a substantially inverted U-shaped engaging portion opening downward,

the holder main body has a pair of board holding portions and a signal line holding portion, the signal line holding portion being interposed between first lengthwise end portions of the pair of board holding portions, the signal line holding portion has a plurality of signal line guide grooves for positioning and fixing the signal lines with respect to the connection portions of the circuit board, and inner surfaces of the pair of board holding portions are provided with a pair of board guide grooves for movably guiding opposite widthwise end portions of the circuit board toward the signal line holding portion; and

shielding means for covering all around a rear end portion of the plug portion, the circuit board, and the holder, excluding a front end portion of the plug portion and an area for leading out the cable, the shielding means being adapted to restrict movement of the plug portion, the circuit board, and the holder;

wherein the engaging portion has:

a pair of column portions respectively provided on first widthwise end surfaces of the pair of board holding portions of the holder main body; and

a beam portion suspended across the column portions,

the shielding means has:

a first shield plate that is in contact with second widthwise end surfaces of the pair of board holding portions of the holder main body;

a second shield plate that is in contact with the beam portion of the engaging portion and faces the first shield plate with the circuit board and the holder therebetween;

a substantially U-shaped third shield plate that is in contact with first widthwise ends of the first and second shield plates and is also in contact with one of the board holding portions of the holder main body and one of the column portions of the engaging portion;

a substantially U-shaped fourth shield plate that is in contact with second widthwise ends of the first and second shield plates and is also in contact with other one of the board holding portions of the holder main body and other one of the column portions of the engaging portion; and

a holding shield member of a rectangular cylindrical shape with a bottom portion, the holding shield member being configured to cover and hold first lengthwise end portions of the first, second, third, and fourth shield plates and to contact with a first lengthwise end portion of the holder,

wherein the front end portion of the plug portion is exposed from space formed by the second lengthwise end portions of the first, second, third, and fourth shield plates, and

wherein the bottom portion of the holding shield member has a leading-out portion for leading out the cable.

9. The cable plug assembly according to claim 8 , wherein the holding shield member has:

a rectangular cylindrical box portion for covering the first lengthwise end portions of the first, second, third, and fourth shield plates; and

four closing plates that are bent at a substantially right angle from four sides of a first lengthwise end of the box portion in such a manner to form the bottom portion of the holding shield member, and

space formed among top portions of the four closing plates serves as the leading-out portion.