Imaging unit and endoscope
An imaging unit includes: an imaging element including a light receiver and a connection terminal formed on a back surface of the imaging element; a flexible printed circuit board including a connection electrode forming region, a cable connection electrode forming region, and a bent portion provided between the connection electrode forming region and the cable connection electrode forming region; and sealing resin filled around a junction between the imaging element and the flexible printed circuit board. The bent portion includes: a first bent portion that is bent toward the imaging element from the connection electrode forming region located parallelly to the light receiver of the imaging element; and a second bent portion that is provided continuously with the first bent portion and lets the cable connection electrode forming region extend in a direction opposite to a direction toward the imaging element.
1. An imaging unit, comprising:
an imaging element including:
an image sensor configured to receive light and generate an image signal by photoelectrically converting the light; and
a connection terminal formed on a back surface of the imaging element;
a flexible printed circuit board including:
a connection electrode forming region where a connection electrode connected to the connection terminal is formed;
a cable connection electrode forming region where a cable connection electrode connected to a cable is formed; and
a bent portion provided between the connection electrode forming region and the cable connection electrode forming region; and
sealing resin filled around a junction between the imaging element and the flexible printed circuit board, wherein
the bent portion includes:
a first bent portion that is bent toward the imaging element from the connection electrode forming region located parallelly to the image sensor of the imaging element; and
a second bent portion that is provided continuously with the first bent portion and lets the cable connection electrode forming region extend in a direction opposite to a direction toward the imaging element, and
a part of the second bent portion is in contact with the back surface of the imaging element.
2. The imaging unit according to claim 1 , wherein a protruding portion is formed at a position of the back surface of the imaging element, the position being where the bent portion is positioned, and a part of the second bent portion is in contact with the protruding portion.
3. The imaging unit according to claim 1 , wherein the bent portion includes a third bent portion, and bending of the bent portion at the third bent portion lets the cable connection electrode forming region be disposed to be positioned near a center of a plane of projection of the imaging element, the projection being made in an optical axis direction of the imaging element.
4. The imaging unit according to claim 1 , wherein
the flexible printed circuit board includes:
a base material portion that is insulating; and
a wiring portion, and
a part of the base material portion has been removed at the bent portion.
5. The imaging unit according to claim 4 , wherein sealing resin covers around a part of the wiring portion, the part being where the base material portion has been removed.
6. The imaging unit according to claim 1 , further comprising:
a substrate on a back surface of the imaging element, the substrate being selected from a group including:
a silicon substrate;
a ceramic substrate;
a three-dimensional substrate made of a molded interconnect device; and
a rigid substrate, wherein
a front surface of the substrate is connected to the back surface of the imaging element, the flexible printed circuit board is connected to a back surface of the substrate, and the second bent portion is in contact with the back surface of the substrate.
7. The imaging unit according to claim 1 , wherein a notched portion having a wall forming an inclined surface is formed at a position of the back surface of the imaging element, the position being where the bent portion is positioned, and a part of an area from the first bent portion to the second bent portion is in contact with the wall.
8. The imaging unit according to claim 7 , wherein a notched portion having a wall forming an inclined surface is formed at an opposite position of the back surface of the imaging element, the opposite position being opposite to the position where the bent portion is positioned.
9. The imaging unit according to claim 1 , wherein the flexible printed circuit board is positioned in a plane of projection of the imaging element, the projection being made in an optical axis direction of the imaging element.
10. An endoscope, comprising:
the imaging unit according to claim 1 ; and
an insertion portion that has a distal end portion and is insertable into a subject, the distal end portion being formed of a rigid member and being tubular, wherein
the insertion portion includes the imaging unit in a space inside the distal end portion.