Patent Publication Number: US-2017360284-A1

Title: Endoscope device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of PCT international application Ser. No. PCT/JP2015/081480 filed on Nov. 9, 2015 which designates the United States, incorporated herein by reference, and which claims the benefit of priority from Japanese Patent Applications No. 2015-048711, filed on Mar. 11, 2015, incorporated herein by reference. 
    
    
     BACKGROUND 
     The present disclosure relates to an endoscope device. 
     In the related art, endoscope devices have been widely used for various inspections in a medical field and an industrial field. Among them, since a medical endoscope device is capable of obtaining an in-vivo image even without incision of the subject, by inserting a flexible insertion section having an elongated shape in which an imaging device is provided at the distal end into a subject such as a patient, and is capable of performing a therapeutic treatment by causing a treatment tool to protrude from the distal end of the insertion section as necessary, the medical endoscope device is widely used. 
     The imaging device used in such an endoscope device includes a semiconductor chip on which an image sensor is formed, and a circuit board on which electronic components such as capacitors or IC chips constituting a drive circuit of the image sensor are mounted, and a signal cable is soldered to the circuit board. The semiconductor chip has a peripheral circuit section which transmits and receives signals between a light-receiving section and external components, on a semiconductor substrate having the light-receiving section formed thereon. In recent years, however, in order to improve the performance of the imaging device, Low-k film of low dielectric constant is used as the material of the insulating layer of the semiconductor chip. 
     Since the Low-k film is inferior in moisture resistance, if the Low-k film is exposed to the outer circumferential portion of the semiconductor chip, water penetrates into the insulating layer, which may cause a malfunction or corrosion of the metal wiring. Thus, there has been proposed an imaging device in which a guard ring made of a material having excellent moisture resistance is formed on the outer circumference of the light-receiving sections and the like in a plurality of insulating members of the semiconductor chip having the light-receiving sections formed thereon (see, for example, JP 2014-216554 A). 
     SUMMARY 
     An endoscope device according to one aspect of the present disclosure includes: an imaging unit including a semiconductor chip including an image sensor formed thereon, and a protective glass adhered on the image sensor with an adhesive layer; and a holder configured to hold the imaging unit by fitting the protective glass therein, wherein the semiconductor chip includes: a light-receiving section configured to generate an image signal by performing photoelectric conversion of light; a peripheral circuit section configured to receive the image signal from the light-receiving unit and transmit a driving signal to the light-receiving unit; a guard ring surrounding the light-receiving section and the peripheral circuit section; and a plurality of metal dots formed on an outer circumference of the guard ring, wherein the protective glass is adhered to the semiconductor chip by the adhesive layer so as to cover the light-receiving section, the peripheral circuit section, the guard ring, and the metal dots, and wherein the metal dots are formed at a same interval from the outer circumference of the guard ring to a connection end portion of a connecting surface between the semiconductor chip and the protective glass. 
     The above and other objects, features, advantages and technical and industrial significance of this disclosure will be better understood by reading the following detailed description of presently preferred embodiments of the disclosure, when considered in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram schematically illustrating an overall configuration of an endoscope system according to a first embodiment of the present disclosure; 
         FIG. 2  is a partial cross-sectional view of a distal end of the endoscope device illustrated in  FIG. 1 ; 
         FIG. 3  is a plan view of a semiconductor chip used in the imaging unit of  FIG. 2 ; 
         FIG. 4  is a partial cross-sectional view of the imaging unit of  FIG. 2 ; 
         FIG. 5  is an enlarged cross-sectional view of a metal dot of  FIG. 4 ; 
         FIG. 6  is a partially enlarged view illustrating a modified example of the metal dot; 
         FIG. 7  is a partial cross-sectional view of an imaging unit according to a modified example of the first embodiment of the present disclosure; 
         FIG. 8  is a partial cross-sectional view of an imaging unit according to a second embodiment of the present disclosure; 
         FIG. 9  is a plan view of a semiconductor chip used in the imaging unit of  FIG. 8 ; 
         FIG. 10  is a partial cross-sectional view of an imaging unit according to a modified example of the second embodiment of the present disclosure; 
         FIG. 11  is a partial cross-sectional view of an imaging unit according to a third embodiment of the present disclosure; 
         FIG. 12A  is a partial cross-sectional view of an imaging unit according to a fourth embodiment of the present disclosure; 
         FIG. 12B  is a front view of the imaging unit according to the fourth embodiment of the present disclosure; 
         FIG. 13  is a plan view of a semiconductor chip used in an imaging unit according to a fifth embodiment of the present disclosure; and 
         FIG. 14  is a partial cross-sectional view of an imaging unit according to the fifth embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, an endoscope device provided with an imaging unit will be described as modes for carrying out the present disclosure (hereinafter referred to as “embodiments”). Further, the present disclosure is not limited by such embodiments. Furthermore, in the description of the drawings, the same parts are denoted by the same reference numerals. Furthermore, the drawings are schematic, a relation between the thickness and the width of each member, a ratio of each member and the like are different from the reality. In addition, portions having dimensions and ratios different from each other are also included in the drawings. 
     First Embodiment 
       FIG. 1  is a diagram schematically illustrating an overall configuration of an endoscope system according to an embodiment of the present disclosure. As illustrated in  FIG. 1 , an endoscope system  1  includes an endoscope device  2 , a universal cord  3 , a connector unit  5 , a processor (control device)  6 , a display device  7 , and a light source device  8 . 
     The endoscope device  2  captures an in-vivo image of a subject and outputs an image signal, by inserting an insertion section  30  into the subject. An electric cable bundle inside the universal cord  3  extends to the insertion section  30  of the endoscope device  2 , and is connected to the imaging unit provided at a distal end portion  3 A of the insertion section  30 . 
     An operating unit  4  provided with various buttons and knobs which operate the endoscope function is connected to a proximal end side of the insertion section  30  of the endoscope device  2 . The operating unit  4  is provided with a treatment tool insertion port  4   a  through which treatment tools such as a biological forceps, an electric scalpel and a test probe are inserted into the body cavity of the subject. 
     The connector unit  5  is provided at the proximal end of the universal cord  3 , and is connected to the light source device  8  and the processor  6  to perform predetermined signal processing on the image signal which is output from the imaging device of the distal end portion  3 A connected to the universal cord  3  and to perform an analog-to-digital conversion (A/D conversion) of the image signal and output the image signal. 
     The processor  6  performs predetermined image processing on the image signal which is output from the connector unit  5 , and controls the entire endoscope system  1 . The display device  7  displays the image signal processed by the processor  6 . 
     The pulsed white light turned on by the light source device  8  is illumination light that is emitted from the distal end of the insertion section  30  of the endoscope device  2  toward the subject via the universal cord  3  and the connector unit  5 . The light source device  8  is configured, for example, using a white LED. 
     The insertion section  30  includes a distal end portion  3 A on which the imaging device is provided, a bending portion  3 B connected to the proximal end side of the distal end portion  3 A and freely bendable in a plurality of directions, and a flexible tube section  3 C connected to the proximal end side of the bending portion  3 B. The image signal of the image captured by the imaging device provided at the distal end portion  3 A is connected, for example, to the connector unit  5  via the operating unit  4  by the universal cord  3  having the length of several meters. The bending portion  3 B is bent by operating a bending operation knob provided on the operating unit  4 , and is freely bendable in four directions, for example, upward, downward, rightward, and leftward along with the pulling and loosening of the bending wire inserted into the insertion section  30 . 
     A light guide bundle (not illustrated) which transmits the illumination light from the light source device  8  is disposed in the endoscope device  2 , and an illumination lens (not illustrated) is disposed at an emission end of the illumination light by the light guide bundle. The illumination lens is provided at the distal end portion  3 A of the insertion section  30 , and the illumination light is emitted toward the subject. 
     Next, the configuration of the distal end portion  3 A of the endoscope device  2  will be described in detail.  FIG. 2  is a partial cross-sectional view of the distal end of the endoscope device  2 . In  FIG. 2 , a distal end portion  3 A of the insertion section  30  of the endoscope device  2  and a part of the bending portion  3 B are illustrated. 
     As illustrated in  FIG. 2 , the bending portion  3 B is freely bendable in four directions, upward, downward, leftward, and rightward together with pulling and loosening of a bending wire  82  inserted into a bending tube  81  disposed inside a cladding tube  42  to be described later. An imaging device  35  is provided inside the distal end portion  3 A extending to the distal end side of the bending portion  3 B. 
     The imaging device  35  has a lens unit  43 , and an imaging unit  40  disposed on the proximal end side of the lens unit  43 , and is adhered to the interior of a distal end portion main body  41  with an adhesive  41   a.  The distal end portion main body  41  is formed of a hard member for forming an internal space which stores the imaging device  35 . The proximal end outer circumferential portion of the distal end portion main body  41  is covered with a flexible cladding tube  42 . The member closer to the proximal end side than the distal end portion main body  41  is made of a flexible member so that the bending portion  3 B may be bent. The distal end portion  3 A in which the distal end portion main body  41  is disposed serves as a hard portion of the insertion section  30 . 
     The lens unit  43  has a plurality of objective lenses  43   a - 1  to  43   a - 4 , and a lens holder  43   b  which holds the objective lenses  43   a - 1  to  43   a - 4 . When the distal end of the lens holder  43   b  is inserted and fixed to the interior of the distal end portion main body  41 , the lens unit  43  is fixed to the distal end portion main body  41 . 
     The imaging unit  40  includes a semiconductor chip  44  having a light-receiving section which generates an image signal by receiving light such as CCD or CMOS to perform the photoelectric conversion, a flexible printed circuit board  45  (hereinafter referred to as “FPC board  45 ”) which is bent in a U shape and is connected to the back side of the light-receiving surface of the semiconductor chip  44  on a surface serving as a U-shaped bottom surface portion, and a protective glass  49  adhered to the semiconductor chip  44  in a state of covering the light-receiving surface of the semiconductor chip  44 . On the FPC board  45 , electronic components  55  to  57  constituting the drive circuit of the image sensor formed on the semiconductor chip  44  are mounted. The electronic components  55  to  57  are mounted inside the U-shaped bent portion of the FPC board  45 , and the inner side of the FPC board  45  bent in a U shape and mounted with the electronic components  55  to  57  is sealed with a sealing resin  54   b.  Further, the distal ends of each signal cable  48  of an electric cable bundle  47  are connected to the proximal end side of the FPC board  45 . Electronic components other than electronic components constituting the drive circuit of the image sensor may be mounted on the FPC board  45 . 
     The proximal ends of each signal cable  48  extend in the proximal end direction of the insertion section  30 . The electric cable bundle  47  is disposed to be inserted through the insertion section  30  and extends to the connector unit  5 , via the operating unit  4  and the universal cord  3  illustrated in  FIG. 1 . 
     The subject image formed by the objective lenses  43   a - 1  to  43   a - 4  of the lens unit  43  is detected by the light-receiving section of the semiconductor chip  44  disposed at the image forming positions of the objective lenses  43   a - 1  to  43   a - 4 , and is converted into an image signal. The image signal is output to the processor  6  via the signal cable  48  connected to the FPC board  45  and the connector unit  5 . 
     The semiconductor chip  44  is connected to the FPC board  45  by a bump  44   h  (see  FIG. 4 ), and the connection circumference between the semiconductor chip  44  and the FPC board  45  is filled with a sealing resin  54   a.  The semiconductor chip  44 , and the connecting section between semiconductor chip  44  and the FPC board  45  are covered with a metal reinforcing member  52 . In order to prevent the influence of external static electricity on the electronic components  55  to  57  on the FPC board  45 , the reinforcing member  52  is installed apart from the semiconductor chip  44  and the FPC board  45 . 
     The outer circumference of the imaging unit  40  and the distal end portion of the electric cable bundle  47  is covered with a heat shrinkable tube  50  in order to improve resistance. Inside the heat shrinkable tube  50 , a gap between the components is filled with an adhesive resin  51 . 
     An image sensor holder  53  holds the semiconductor chip  44  adhered to the protective glass  49 , by fitting the outer circumferential surface of the protective glass  49  to the inner circumferential surface on the proximal end side of the image sensor holder  53 . The proximal end side outer circumferential surface of the image sensor holder  53  is fitted to the distal end side inner circumferential surface of the reinforcing member  52 . A proximal end side outer circumferential surface of the lens holder  43   b  is fitted to the distal end side inner circumferential surface of the image sensor holder  53 . In the state in which the respective members are fitted to each other, the outer circumferential surface of the lens holder  43   b,  the outer circumferential surface of the image sensor holder  53 , and the distal end side outer circumferential surface of the heat shrinkable tube  50  are fixed to the inner circumferential surface of the distal end of the distal end portion main body  41  by the adhesive  41   a.    
     Next, the imaging unit  40  will be described.  FIG. 3  is a plan view of the semiconductor chip  44  used in the imaging unit  40 .  FIG. 4  is a partial cross-sectional view of the imaging unit according to the first embodiment of the present disclosure, and illustrates a cross-sectional view of a connecting section between the protective glass  49  of the imaging unit  40  and the semiconductor chip  44 . 
     The semiconductor chip  44  includes a light-receiving section  44   a  which performs photoelectric conversion of the light input from the lens unit  43  to generate an image signal, a peripheral circuit section  44   b  which receives the image signal from the light-receiving section  44   a  and transmits the driving signal to the light-receiving section  44   a,  a plurality of electrode pads  44   c,  a guard ring  44   d  which surrounds the light-receiving section  44   a,  the peripheral circuit section  44   b  and the electrode pad  44   c,  and a plurality of metal dots  44   e  formed on the outer circumference of the guard ring  44   d.  The protective glass  49  is formed to have the same planar dimensions orthogonal to the optical axis direction as the semiconductor chip  44 , and is adhered by an adhesive layer  54   c  to cover the light-receiving section  44   a,  the peripheral circuit section  44   b,  the electrode pad  44   c,  the guard ring  44   d,  and the plurality of metal dots  44   e.    
     The light-receiving section  44   a  is formed on a semiconductor substrate  44   k  made of silicon or the like. On a surface opposite to the surface on which the light-receiving section  44   a  of the semiconductor substrate  44   k  is formed, the same number of back electrodes  44   g  and dummy electrodes  44   i  as the electrode pads  44   c  are formed. The back electrode  44   g  is formed at the same position as the position at which the electrode pad  44   c  of the semiconductor substrate  44   k  is formed, and is made conductive by a through-electrode  44   f.  The dummy electrode  44   i  is formed to be symmetrical with the back electrode  44   g,  and maintains a constant connection interval between the semiconductor chip  44  and the FPC board  45  when connected to the FPC board  45  via the bump  44   h.    
     On the surface of the semiconductor substrate  44   k  on which the light-receiving section  44   a  is formed, an insulating layer  44   m  made up of a plurality of insulating members is laminated. In the insulating layer  44   m  of the first embodiment, insulating members are laminated in four layers, but the number of layers on which the insulating member is laminated is not limited thereto. As the insulating member, it is preferable to use a material having a low dielectric constant, and for example, a Low-k film with SiO 2  or resin as a base material may be suitably used. Since the Low-k film has a low dielectric constant, speed of the signal transmission in the wiring layer may be enhanced. 
     The peripheral circuit section  44   b  and the electrode pad  44   c  are formed by electrically connecting a via disposed in each insulating member constituting the insulating layer  44   m  and the wiring layer disposed on the insulating member. 
     The guard ring  44   d  is provided to surround the light-receiving section  44   a,  the peripheral circuit section  44   b,  and the electrode pad  44   c,  and to traverse in the thickness direction of the insulating layer  44   m  from the surface side of the insulating layer  44   m  abutting on the semiconductor substrate  44   k  to the surface side abutting on the adhesive layer  54   c.  Thus, moisture is prevented from entering the inner region of the guard ring  44   d.  The guard ring  44   d  is made of a metal material such as copper used as a material of the peripheral circuit section  44   b.    
     The metal dot  44   e  is made of a metal material such as copper, and a plurality of metal dots  44   e  is formed on the outer circumferential side of the guard ring  44   d.  In the first embodiment, four rows of metal dots  44   e  are formed in the up-down direction and the left-right direction on the outer circumference of the guard ring  44   d.    FIG. 5  illustrates an enlarged cross-sectional view of the metal dot  44   e.  The metal dot  44   e  includes a dummy via  441   a  formed in the first insulating member, a dummy pad  442   a  formed on the first insulating member, a dummy via  441   b  formed in the second insulating member, a dummy pad  442   b  formed on the second insulating member, a dummy via  441   c  formed in the third insulating member, a dummy pad  442   c  formed on the third insulating member, a dummy via  441   d  formed in the fourth insulating member, and a dummy pad  442   d  formed on the fourth insulating member. The diameters of the dummy pads  442   a  to  442   d  are approximately 5 μm, and the metal dots  44   e  are disposed at a pitch in which the dummy pads do not interfere with each other. The diameter of the dummy pad is not limited to this size. The metal dots  44   e  are disposed at the same interval, but the arrangement interval may be changed, for example, so that the inner side close to the guard ring  44   d  is dense and the outer side is sparse. The dummy vias  441   a  to  441   d  and the dummy pads  442   a  to  442   d  are disposed to abut on each other so as to be located at the same position in the thickness direction of the insulating layer  44   m  from the surface side of the insulating layer  44   m  abutting on the semiconductor substrate  44   k  to the surface side abutting on the adhesive layer  54   c.  As in the metal dots  44   e,  the guard ring  44   d  is also formed by disposing the dummy vias disposed in each insulating member and the dummy pads disposed on the insulating member constituting the insulating layer  44   m  to abut on each other. 
     In the first embodiment, even if a Low-k film or the like which is inferior in adhesion and is mechanically fragile is used as the insulating member of the semiconductor chip  44 , since a plurality of metal dots  44   e  is disposed at the connection end portion of the connecting surface between the semiconductor chip  44  susceptible to stress and the protective glass  49 , peeling of the insulating member may be prevented. After forming a large number of semiconductor chips  44  at a time, the semiconductor chip  44  is diced at a predetermined position to divide the semiconductor chips  44 . However, by forming the metal dots  44   e  on the outer circumferential portion of the semiconductor chip  44 , it is possible to prevent peeling of the insulating layer  44   m  at the time of dicing. 
     Further, the metal dots  44   e  may be disposed such that the dummy vias  441   a  to  441   d  may be disposed to be shifted in the thickness direction of the insulating layer  44   m.    FIG. 6  is a partially enlarged view illustrating a modified example of a metal dot. As illustrated in  FIG. 6 , in a metal dot  44   e ′ according to the modified example, the dummy vias  441   a  to  441   d  are disposed to be shifted in zigzag in the thickness direction of the insulating layer  44   m.  Even when the dummy vias  441   a  to  441   d  are disposed to be shifted in the thickness direction of the insulating layer  44   m,  since the dummy vias  441   a  to  441   d  and the dummy pads  442   a  to  442   d  are disposed to abut on each other from the surface side of the insulating layer  44   m  abutting on the semiconductor substrate  44   k  to the surface side abutting on the adhesive layer  54   c,  it is possible to prevent peeling of the laminated insulating layers  44   m,  when stress is applied to the connection end portion between the semiconductor chip  44  and the protective glass  49 . 
     Further, by forming the metal dots  44   e  in the diced portion in the wafer before dividing the semiconductor chip  44 , it is possible to effectively prevent peeling of the insulating layer  44   m  or chipping of the semiconductor substrate  44   k.  When forming the metal dots  44   e  in the diced portion, if the dummy vias  441   a  to  441   d  are disposed to be shifted in the thickness direction of the insulating layer  44   m  as in the metal dots  44   e ′ according to the modified example, the consumption of the dicing blade may be reduced. 
     In addition, when the planar dimension of the protective glass  49  orthogonal to the optical axis direction is larger than that of the semiconductor chip  44 , it is possible to fill the sealing resin and prevent peeling of the insulating member from the side surface direction of the semiconductor chip  44 .  FIG. 7  is a partial cross-sectional view of an imaging unit according to a modified example of the first embodiment of the present disclosure.  FIG. 7  is a cross-sectional view of a connecting section between the protective glass  49  and the semiconductor chip  44  of the imaging unit according to the modified example of the first embodiment of the present disclosure. 
     In the imaging unit  40 A according to the modified example of the first embodiment of the present disclosure, the protective glass  49  has a planar dimension orthogonal to the optical axis direction larger than that of the semiconductor chip  44 . On the connecting surface of the protective glass  49  with the semiconductor chip  44 , a portion which does not abut on the semiconductor chip  44  is filled with a sealing resin  46 , and the side surface of the semiconductor chip  44  and the outer circumferential portion of the connecting surface of the protective glass  49  are adhered by a sealing resin  46 . By sealing the side surface of the semiconductor chip  44  with the sealing resin  46 , it is possible to prevent peeling of the insulating member from the side surface direction of the semiconductor chip  44 . 
     Second Embodiment 
       FIG. 8  is a partial cross-sectional view of an imaging unit according to a second embodiment of the present disclosure.  FIG. 8  is a cross-sectional view of a connecting section between the protective glass  49  and a semiconductor chip  44 B of the imaging unit according to the second embodiment of the present disclosure.  FIG. 9  is a plan view of a semiconductor chip used in the imaging unit of  FIG. 8 . 
     In an imaging unit  40 B according to the second embodiment, as illustrated in  FIG. 9 , four rows of metal dots  44   e  are formed on the upper and lower sides and the left side of the guard ring  44   d,  and eight rows of metal dots  44   e  are formed on the right side. Further, the left side of the guard ring  44   d  is the left side when viewed in the plan view of  FIG. 9  (the outer circumference side of the guard ring  44   d  close to the peripheral circuit section  44   b ), and the right side is the right side when viewed in the plan view of  FIG. 9  (the outer circumferential side of the guard ring  44   d  close to the electrode pad  44   c ). 
     The protective glass  49  is adhered by the adhesive layer  54   c  to cover the light-receiving section  44   a,  the peripheral circuit section  44   b,  the electrode pad  44   c,  the guard ring  44   d,  and the metal dots  44   e  of four rows of upper, lower, right and left sides. Among the metal dots  44   e  formed in eight rows on the right side of the guard ring  44   d,  the inner four rows of metal dots  44   e  are covered with the protective glass  49 , but the outer four rows of metal dots  44   e  are not covered with a protective glass. 
     In the second embodiment, all the metal dots  44   e  are not covered with the protective glass  49 . However, since a plurality of metal dots  44   e  is disposed at the connection end portion of the connecting surface between the semiconductor chip  44 B prone to stress and the protective glass  49 , even when a Low-k film or the like which is inferior in adhesion and mechanically fragile is used as an insulating member of the semiconductor chip  44 B, peeling of the insulating member may be prevented. 
     Further, sealing resin may be filled on the metal dots  44   e  of the semiconductor chip  44 B not covered with the protective glass  49  to prevent peeling of the insulating member.  FIG. 10  is a partial cross-sectional view of an imaging unit according to a modified example of the second embodiment of the present disclosure.  FIG. 10  illustrates a cross-sectional view of a connecting section between the protective glass  49  and the semiconductor chip  44 B of the imaging unit according to the modified example of the second embodiment of the present disclosure. 
     In an imaging unit  40 C according to the modified example of the second embodiment of the present disclosure, a sealing resin  46   c  is filled on the metal dots  44   e  of the semiconductor chip  44 B which is not covered with the protective glass  49 , and the connecting surface of the semiconductor chip  44 B and the side surface of the protective glass  49  are adhered by the sealing resin  46   c.  Since the metal dots  44   e  are formed on the connecting surface of the semiconductor chip  44 B sealed with the sealing resin  46   c,  it is possible to improve the adhesive force with the sealing resin  46   c,  and to prevent peeling of the insulating member of the semiconductor chip  44 B. 
     Third Embodiment 
       FIG. 11  is a partial cross-sectional view of an imaging unit according to a third embodiment of the present disclosure.  FIG. 11  is a cross-sectional view of a connecting section between the protective glass  49  and the semiconductor chip  44  of the imaging unit according to the third embodiment of the present disclosure. 
     In an imaging unit  40 D according to the third embodiment, an adhesive layer  54   c  which adheres the semiconductor chip  44  and the protective glass  49  has a hollow portion  54   d  on the light-receiving section  44   a.  The adhesive layer  54   c  is disposed on the peripheral circuit section  44   b,  the electrode pad  44   c,  the guard ring  44   d  and the metal dots  44   e,  except on the light-receiving section  44   a,  and the semiconductor chip  44  and the protective glass  49  are adhered with the adhesive layer  54   c  on the peripheral circuit section  44   b,  the electrode pad  44   c,  the guard ring  44   d,  and the metal dots  44   e.    
     In the third embodiment, the adhesive layer  54   c  is disposed on the peripheral circuit section  44   b,  the electrode pad  44   c,  the guard ring  44   d  and the metal dots  44   e,  except on the light-receiving section  44   a.  Thus, it is possible to prevent entry of moisture from the adhesive surface between the semiconductor chip  44  and the protective glass  49 . By providing a hollow portion  54   d  on the light-receiving section  44   a,  it is possible to prevent propagation of stress to the insulating layer  44   m  on the light-receiving section  44   a  with the adhesive layer  54   c.  Accordingly, it is possible to prevent peeling of the insulating member that constitutes the insulating layer  44   m  on the light-receiving section  44   a.    
     Fourth Embodiment 
       FIG. 12A  is a partial cross-sectional view of an imaging unit according to a fourth embodiment of the present disclosure.  FIG. 12B  is a front view of the imaging unit according to the fourth embodiment of the present disclosure.  FIG. 12A  illustrates a cross-sectional view of a connecting section between the protective glass  49  and a semiconductor chip  44 E of the imaging unit according to the fourth embodiment of the present disclosure. 
     In an imaging unit  40 E according to the fourth embodiment, a through-electrode  44   f,  a back electrode  44   g,  and a dummy electrode  44   i  are not formed on the semiconductor substrate  44   k,  and an inner lead  45   a  extending from a FPC board via a bump  44   h  is connected to an electrode pad  44   c  of the connecting surface. Although it is not illustrated, the inner lead  45   a  is bent at the side surface of the semiconductor chip  44 E and extends to the back side of the semiconductor chip  44 E. 
     The planar dimension of the protective glass  49  orthogonal to the optical axis direction is formed to be smaller than that of the semiconductor chip  44 E, and the protective glass  49  is adhered by the adhesive layer  54   c  to cover the guard ring  44   d  and the metal dot  44   e  of the three directions, except for the side of the light-receiving section  44   a,  the peripheral circuit section  44   b,  the electrode pad  44   c,  and the electrode pad  44   c.    
     A sealing resin  46   e  is filled on the electrode pad  44   c,  the guard ring  44   d,  and the metal dot  44   e  of the semiconductor chip  44 E which is not covered with the protective glass  49 . In the imaging unit  40 E according to the fourth embodiment of the present disclosure, the sealing resin  46   e  is filled on the connecting surface of the semiconductor chip  44 E not covered with the protective glass  49 , and the connecting surface of the semiconductor chip  44 E and the side surface of the protective glass  49  are adhered by the sealing resin  46   e.  Since the metal dots  44   e  are formed on the connecting surface of the semiconductor chip  44 E sealed with the sealing resin  46   e,  it is possible to improve the adhesive force with the sealing resin  46   e  and to prevent peeling of the insulating member of the semiconductor chip  44 E. 
     Fifth Embodiment 
       FIG. 13  is a plan view of a semiconductor chip used in the imaging unit according to the fifth embodiment of the present disclosure.  FIG. 14  is a partial cross-sectional view of an imaging unit according to a fifth embodiment of the present disclosure, and illustrates a cross-sectional view of a connecting section between the protective glass and the semiconductor chip. 
     In an imaging unit  40 F according to the fifth embodiment, as illustrated in  FIG. 13 , the peripheral circuit section  44   b  and the electrode pad  44   c  are formed on both sides with the light-receiving section  44   a  interposed therebetween, respectively. Inner leads  45   a  extending from the FPC board via the bump  44   h  are connected to the electrode pads  44   c  formed on both sides with the light-receiving section  44   a  interposed therebetween, respectively. The inner lead  45   a  is bent at the side surface of a semiconductor chip  44 F and extends to the back side of the semiconductor chip  44 F. 
     As illustrated in  FIG. 14 , the protective glass  49  is formed to have the same planar dimension orthogonal to the optical axis direction as the semiconductor chip  44 F, and is adhered by the adhesive layer  54   c  cover the light-receiving section  44   a,  the peripheral circuit section  44   b,  the electrode pad  44   c  to which the inner lead  45   a  is connected, the guard ring  44   d,  and the plurality of metal dots  44   e.    
     Even in the fifth embodiment, as in the first embodiment, even when a Low-k film or the like which is inferior in adhesion and mechanically fragile is used as the insulating member of the semiconductor chip  44 F, since the plurality of metal dots  44   e  is disposed at the connecting end portions between the protective glass  49  prone to stress and the semiconductor chip  44 F, peeling of the insulating member may be prevented. Further, since the metal dots  44   e  are formed on the outer circumferential portion of the semiconductor chip  44 F, the semiconductor chip  44 F may prevent chipping of the semiconductor substrate  44   k  in the process of dividing the semiconductor chip  44 F. 
     Since a plurality of metal dots is provided on the outer circumferential portion of the connecting surface between the semiconductor chip and the protective glass, even when stress is applied to the adhesive surface between the semiconductor chip and the protective glass, by the miniaturization of the imaging device of the present disclosure, it is possible to prevent peeling of the insulating member such as the laminated Low-k film. 
     Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the disclosure in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.