JP7270225B2 - Solid-state imaging device - Google Patents

Description

The present disclosure relates to a compact solid-state imaging device provided in an electronic endoscope or the like.

BACKGROUND ART Conventionally, in the medical field, by inserting an elongated insertion portion into a body cavity, a medical endoscope has been used that allows observation of internal organs in a body cavity, and various therapeutic treatments using a treatment instrument inserted through a treatment instrument channel. A viewing scope is provided. In the industrial field, industrial endoscopes are provided that can observe or inspect internal flaws, corrosion, etc. of boilers, turbines, engines, chemical plants, and the like.

Such an endoscope (electronic endoscope) includes, for example, a solid-state imaging device such as a charge-coupled device (abbreviated as CCD) or a solid-state imaging device equipped with electronic components at the distal end of the insertion section. be. A solid-state imaging device receives reflected light from an object to be imaged, photoelectrically converts the light, and transmits the photoelectrically converted signal to an information processing device having a monitor device via a signal cable. The information processing device processes a signal received from the solid-state imaging device, and displays an object captured by the solid-state imaging device in color on a monitor device.

An endoscope with a built-in solid-state imaging device is inserted into, for example, a narrow and tortuous lumen, and therefore, it is desired to reduce the diameter of the insertion portion. In addition, solid-state imaging devices are desired to be compact and small in diameter in order to realize an endoscope that can turn in a small radius and have good operability.

Patent Literature 1 discloses a solid-state imaging device arranged at the distal end of an endoscope. Patent Document 1 discloses a solid-state imaging device in which the size of the entire configuration is reduced by minimizing the sealing and fixing portion formed by the sealing resin as much as possible.

Japanese Unexamined Patent Application Publication No. 2001-17389

FIG. 7 is a cross-sectional view of the solid-state imaging device of Patent Document 1, and FIG. 8 is a plan view of the solid-state imaging device of Patent Document 1. As shown in FIG. In the solid-state imaging device disclosed in Patent Document 1, a transparent member 3 is adhered onto the light-receiving surface of a solid-state imaging element 2, and leads 12 of an FPC 4A (flexible circuit board) are connected to projecting electrodes 2b formed on the light-receiving surface. . In addition, in the solid-state imaging device of Patent Document 1, the peripheral portion of the transparent member 3 and the connecting portions of the solid-state imaging element 2 and the leads 12 of the FPC 4A are sealed with the second sealing resin 25 .

Therefore, in Japanese Unexamined Patent Application Publication No. 2002-100000, the range of the sealing fixing portion 6 formed by the second sealing resin 25 is widened, which hinders downsizing of the solid-state imaging device.

For example, when the solid-state imaging device is viewed from the light-receiving surface side of the solid-state imaging device 2, the sealing fixing portion 6 protrudes from the outer edge of the solid-state imaging device 2, and the size of the solid-state imaging device viewed from the light-receiving surface side is the same as that of the seal. It is determined by the size of the stop fixing portion 6 .

An object of the present disclosure is to provide a more compact solid-state imaging device.

In order to solve the above problems, a solid-state imaging device and a substrate fixed to the solid-state imaging device with a sealing resin on the opposite side of the light-receiving surface of the solid-state imaging device are provided. The outer edge of the substrate viewed from the surface side is within the outer edge of the solid-state imaging device, and the outer edge of the sealing resin viewed from the light-receiving surface side of the solid-state imaging device is within the outer periphery of the solid-state imaging device. A solid-state imaging device is used.

According to the present disclosure, it is possible to provide a more compact solid-state imaging device.

1 is a cross-sectional view showing the configuration of a solid-state imaging device according to Embodiment 1; 1 is a plan view showing the configuration of a solid-state imaging device according to Embodiment 1; FIG. (a) to (f) Cross-sectional views showing the steps of forming the solid-state imaging device according to the first embodiment. (a) to (f) Cross-sectional views showing the steps of forming the solid-state imaging device according to the second embodiment. Sectional view showing the configuration of a solid-state imaging device according to the third embodiment Sectional view showing the configuration of a solid-state imaging device according to the fourth embodiment Cross-sectional view showing the configuration of a conventional solid-state imaging device Plan view showing the configuration of a conventional solid-state imaging device

(Embodiment 1)
Embodiment 1 of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view of the solid-state imaging device according to Embodiment 1 of the present disclosure, and FIG. 2 is a plan view of the solid-state imaging device according to Embodiment 1 of the present disclosure.

<Structure>
As shown in FIG. 1, the solid-state imaging device according to Embodiment 1 of the present invention has a rectangular parallelepiped solid-state imaging element 23 . The solid-state imaging device 23 has a light receiving surface 23a and a surface 23b.

A rectangular parallelepiped transparent member 21 (cover glass) is arranged on the light receiving surface 23 a of the solid-state imaging device 23 . The transparent member 21 is fixed to the solid-state imaging device 23 with an adhesive 22 . A plurality of connection terminals 9 are formed on the surface 23 b of the solid-state imaging device 23 .

A convex main substrate 28 is arranged on the surface 23 b of the solid-state imaging device 23 . The solid-state imaging device 23 is fixed to the main substrate 28 with the first sealing resin 24 and the second sealing resin 25 .

A plurality of connection terminals 11 are formed on the upper surface of the protrusion of the main board 28 . Protruding electrodes 10 are provided between the connection terminals 11 of the main substrate 28 and the connection terminals 9 formed on the surface 23b of the solid-state imaging device 23 . The protruding electrodes 10 electrically connect the main substrate 28 and the solid-state imaging device 23 .

A plurality of connection terminals 14 are formed on the upper surface of the base portion of the main board 28 . A plurality of chip components 26 having connection terminals 32 are arranged in the chip component 26 (the space 27 between the surface 23b of the solid-state imaging device 23 and the base portion of the main substrate 28).

Projecting electrodes 13 are provided between the connection terminals 14 of the main board 28 and the connection terminals 32 of the chip component 26 . The projecting electrodes 13 electrically connect the main board 28 and the chip component 26 . The second sealing resin 25 fills the chip component 26 . Cable connection terminals 15 are formed on the side surface of the base portion of the main board 28 .

The area of the transparent member 21 and the adhesive 22 in plan view is smaller than the area of the solid-state imaging device 23 in plan view (see FIG. 2). In plan view, the outer edges of the transparent member 21 and the adhesive 22 are arranged so as to fit within the outer edge of the solid-state imaging device 23 (see FIG. 2).

Also, the areas of the first sealing resin 24, the second sealing resin 25, and the main substrate 28 in plan view are smaller than the area of the solid-state imaging device 23 in plan view. In plan view, the outer edges of the first sealing resin 24 and the second sealing resin 25 and the outer edge of the main substrate 28 are arranged so as to fit within the outer edge of the solid-state imaging device 23 .

As a result, the solid-state imaging element 23 is the element that maximizes the width dimension of the solid-state imaging device (the size in plan view, the dimension in the vertical and horizontal directions in FIG. 2). The solid-state imaging device can be miniaturized to the limit (to the size of the solid-state imaging device 23).

The area of the transparent member 21 and the adhesive 22 in plan view may be the same as the area of the solid-state imaging device 23 in plan view. The shape of the transparent member 21 and the adhesive 22 in plan view may be the same as the shape of the solid-state imaging device 23 in plan view.

Further, the areas of the first sealing resin 24, the second sealing resin 25, and the main substrate 28 in plan view may be the same as the area of the solid-state imaging device 23 in plan view. The first sealing resin 24, the second sealing resin 25, and the main substrate 28 may have the same shape in plan view as the shape of the solid-state imaging device 23 in plan view.

<Manufacturing method>
A solid-state imaging device can be produced by the steps shown in FIG.

First, as indicated by arrow A in FIG. Also, the transparent member 21 is placed on the light receiving surface 23 a of the solid-state imaging device 23 and fixed with an adhesive 22 .

On the other hand, as indicated by arrow B in FIG. Also, the connection terminals 32 are formed on the chip component 26 , and the projecting electrodes 13 are formed on the connection terminals 32 . Also, the chip component 26 is arranged on the chip component 26 and the projecting electrodes 13 are connected to the connection terminals 14 on the main board 28 . Thereby, the chip component 26 and the main board 28 are electrically connected.

Next, as indicated by arrow C in FIG. 3, the chip component 26 is filled with the second sealing resin 25 . Next, as indicated by arrow D in FIG. 3, the main board 28 is diced into individual pieces. Next, as indicated by arrow E in FIG. 3, the first sealing resin 24 is applied to the surface of the main substrate 28 on which the projecting electrodes 10 are formed.

Next, as indicated by arrow F in FIG. 3, the surface of the main substrate 28 on which the protruding electrodes 10 are formed and the surface of the solid-state imaging device 23 on which the connection terminals 9 are formed are arranged to face each other. Then, the projecting electrodes 10 are connected to the connection terminals 9 , and the main substrate 28 and the solid-state imaging device 23 are fixed with the first sealing resin 24 . Thereby, the solid-state imaging device 23 and the main board 28 are electrically connected. A solid-state imaging device is completed by the above steps.

<Action>
The solid-state imaging device 23 receives the light reflected by the object to be imaged by the light receiving surface 23a through the transparent member 21, and converts the received light into an electric signal.

The electrical signal is transmitted to the main board 28 electrically connected to the solid-state imaging device 23 . The electrical signal is transmitted to the chip component 26 electrically connected to the main board 28 . The chip component 26 performs predetermined signal processing on the transmitted electrical signal and transmits the processed signal to the main board 28 . The electrical signal transmitted to the main board 28 via the chip component 26 is transmitted from the cable connection terminal 15 to an external device (for example, an information processing device having a monitor device).

<Each element>
An example of the size of each member is shown below.

Main substrate 28: 1 mm x 1 mm x 0.6 mm thickness
Chip component 26: 0.6 mm x 0.3 mm x thickness 0.3 mm or less Transparent member 21: 1 mm x 1 mm x thickness 0.3 mm
Solid-state imaging device 23: 1 mm × 1 mm × thickness 0.1 mm
The planar view area of the transparent member 21 and the planar view area of the main substrate 28 may be smaller than the planar view area of the solid-state imaging device 23 as shown in FIGS.

<Chip component 26>
The chip component 26 is, for example, a capacitor, but may be a resistor. The chip component 26 also has connection terminals 32 for transmitting and receiving electric signals. In plan view, the chip component 26 is arranged so as to fit within the outer edge of the solid-state imaging device 23 .

<Transparent member 21>
The transparent member 21 is a transparent rectangular parallelepiped optical member. The width dimension of the solid-state imaging device (the vertical and horizontal dimensions when the solid-state imaging device is viewed in plan) is set to the width dimension of the solid-state imaging device 23 to reduce the size. width dimension or less.

<Solid-state imaging device 23>
The solid-state imaging device 23 is a CCD image sensor, a CMOS image sensor, or the like that detects light and converts it into an electrical signal. The solid-state imaging device 23 may incorporate a circuit for signal processing. Alternatively, the solid-state imaging device 23 may be stacked with a device having a signal processing function. The solid-state imaging device 23 has connection terminals 9 for transmitting and receiving electric signals.

<Connection terminals 9, 11, 32, 14>
The connection terminals 9, 11, 32, 14 are made of aluminum, for example. The connection terminals 9, 11, 32, and 14 may be made of metal such as copper, which has a higher electrical conductivity than aluminum. When copper is used for the connection terminals 9, 11, 32, and 14, the copper may be plated with nickel/gold to make it difficult to oxidize.

<Cable connection terminal 15>
The cable connection terminal 15 is made of, for example, aluminum. For the cable connection terminal 15, a metal such as copper having a higher conductivity than aluminum may be used. When copper is used for the cable connection terminal 15, the copper may be plated with nickel/gold so as to be resistant to oxidation.

<Projection electrodes 10, 13>
The projecting electrodes 10 and 13 are formed of solder, for example. A metal such as copper or gold may be used for the projecting electrodes 10 and 13 .

<Main board 28>
The main substrate 28 is formed of, for example, a ceramic substrate. A build-up board, an aramid epoxy board, a glass epoxy board, or the like may be used for the main board 28 . Spaces 27 (chip components 26) for mounting chip components 26 are formed on the left and right sides of the main board 28 in plan view.

<Chip component 26>
The size of the chip component 26 is, for example, 0.6 mm×0.3 mm×thickness 0.3 mm. Since the chip component 26 is accommodated within the chip component 26 , the width dimension of the solid-state imaging device can be kept the same as the width dimension of the solid-state imaging device 23 .

Two chip components 26 are formed symmetrically with respect to the protrusion of the main board 28 . As a result, the heat dissipation of the solid-state imaging device 23 becomes bilaterally symmetrical, and in-plane variations in electrical characteristics and the like can be suppressed.

Also, the chip parts 26 may be formed on the surface 8b (see FIG. 1) of the main substrate 28 so as to be symmetrical with respect to four points.

<Adhesive 22>
The adhesive 22 is a transparent adhesive such as an ultraviolet curable adhesive. The width dimension of the adhesive 22 is equal to or less than the width dimension of the transparent member 21 .

<First sealing resin 24>
The first sealing resin 24 is an epoxy adhesive. The width dimension of the first sealing resin 24 is equal to or less than the width dimension of the solid-state imaging device 23 . The first sealing resin 24 covers the projecting electrodes 10 that connect the solid-state imaging device 23 and the main substrate 28 .

<Second sealing resin 25>
The width dimension of the second sealing resin 25 is equal to or less than the width dimension of the solid-state imaging device 23 . The second sealing resin 25 has a lower elastic modulus and a higher heat dissipation property than the first sealing resin 24 . The surface of the second sealing resin 25 in contact with the first sealing resin 24 is tapered from the outside toward the inside like the tapered portion 5a in FIG. For example, the interface between the first sealing resin 24 and the second sealing resin 25 is inclined from the inside to the outside of the solid-state imaging device in a direction in which the first sealing resin 24 becomes thinner. By providing the tapered portion 5a in this way, it is possible to prevent the first sealing resin 24 from leaking during manufacturing.

<effect>
By stacking and connecting the transparent member 21, the solid-state imaging device 23, the main board 28, and the chip parts 26 that constitute the solid-state imaging device as in the above structure, the width dimension of the solid-state imaging device can be reduced to that of the solid-state imaging device 23. , and can be miniaturized. Moreover, since the width dimension of the solid-state imaging device can be reduced, for example, the diameter of the insertion portion of an endoscope can be reduced.

In addition, by using two types of sealing resins for fixing the solid-state imaging device, the first sealing resin 24 with high adhesion and the second sealing resin 25 with high heat dissipation, and by making the structure symmetrical. , a highly reliable solid-state imaging device can be provided.
(Second Embodiment): Separation of First Sealing Resins 24 and 5 Next, a second embodiment will be described with reference to FIGS. 4(a) to 4(d). The second embodiment differs from the first embodiment in the shape of the second sealing resin 25 after sealing. Matters not explained are the same as in the first embodiment.
<Process>
First, as shown in FIG. 4A, the adhesive 22 is applied to the light receiving surface 23a side of the solid-state imaging device 23, and then the transparent member 21 is placed to wet and spread the adhesive over the entire light receiving surface 23a. It is fixed by UV rays or heat.

On the other hand, as shown in FIG. 4(b), the main board 28 has the connection terminals 11 and the connection terminals 14, and the connection terminals 11 are provided with projecting electrodes by heating, pressurization, ultrasonic waves, or the like. form 10; The chip component 26 also has connection terminals 32 on which protruding electrodes 13 are formed.
The chip component 26 is arranged on the chip component 26, and the projecting electrodes 13 are connected to the connection terminals 14 on the main substrate 28 by heat treatment such as reflow. Thereby, the chip component 26 and the main board 28 are electrically connected.

Next, as shown in FIG. 4C, the chip components 26 on the main substrate 28 on which the chip components 26 are mounted are filled with the second sealing resin 25 . Thereafter, as shown in FIG. 4(d), the main substrate 28 is diced into individual pieces using a cutting blade or the like.

In the resin sealing process shown in FIGS. 4(c) and 4(d), the periphery of the chip component 26 mounted on the main substrate 28 is filled with sealing resin by potting or the like.

At this time, the second sealing resin 25 is filled so as not to protrude to the side surfaces of the adjacent chip components 26 . By cutting the substrate, it is possible to separate the substrate into individual pieces, and the size of the substrate after cutting and the quality of the cut portion can be improved and stabilized.

In addition, by filling the second sealing resin 25 up to a position where it does not cover the upper surface of the chip component 26, after applying the first sealing resin 24 as shown in FIG. ), when the solid-state imaging device 23 is mounted, the wetting and spreading of the first sealing resin 24 can be stopped at the edge of the chip component 26 .

<Structure>
In the structure of Embodiment 2, the first sealing resin 24 and the second sealing resin 25 are separated. This prevents the first sealing resin 24 from flowing out to the outside of the chip component 26 and the outside of the main substrate 28, thereby realizing a compact structure of the solid-state imaging device.
(Embodiment 3) First sealing resin 24 is drum-shaped Next, Embodiment 3 will be described with reference to FIG. The third embodiment differs from the second embodiment in the shape of the first sealing resin 24 . Matters not described are the same as those in the first and second embodiments.

The shape of the first sealing resin 24 differs depending on the wettability between the first sealing resin 24 and the solid-state imaging device 23 . The shape of the first sealing resin 24 may be not only a fillet shape as shown in FIG. 4(f) of the second embodiment, but also a drum shape as shown in FIG.

The wettability of the first sealing resin 24 to the surfaces of the main substrate 28 and the solid-state imaging device 23 is reduced. Also, the viscosity of the first sealing resin 24 is increased. As a result, when the solid-state imaging device 23 is mounted on the main substrate 28, the central portion of the first sealing resin 24 is pushed out to form a drum shape. As a result, it is possible to absorb more stress applied in the heat treatment and reliability test in the post-process.
(Embodiment 4): Third sealing resin 16
Next, Embodiment 4 will be described with reference to FIG. The fourth embodiment is obtained by adding an improvement in the function of preventing the first sealing resin 24 from flowing out and a second connection between the chip component 26 and the solid-state imaging device 23 in the second and third embodiments. Matters not explained are the same as in the first to third embodiments.

As a method for further improving the outflow prevention function of the first sealing resin 24 and improving the connection reliability between the main substrate 28 and the solid-state imaging device 23, a third sealing separate from the first sealing resin 24 is used. It is a structure in which the resin 16 is formed on the chip component 26 .

The third sealing resin 16 is a material different from that of the first sealing resin 24 , and has a lower elastic modulus and a higher heat dissipation property than the first sealing resin 24 .

The third sealing resin 16 is applied onto the chip parts 26 by potting or the like after the main board 28 is separated into individual pieces, and is heated at a temperature of about 100.degree. C. to 150.degree. After that, when the first sealing resin 24 is applied and the solid-state imaging device 23 is mounted, the first sealing resin 24 spreads out. Prevents spillage to the outside of the substrate 28.

After that, the first sealing resin 24 and the third sealing resin 16 are cured by heating at about 170.degree. C. to 200.degree.

As a result, the outflow of the first sealing resin 24 can be reliably stopped by the third sealing resin 16 .

Furthermore, in Embodiments 2 and 3, the solid-state imaging device 23 is only connected by the metal bumps formed on the central protrusion of the main substrate 28 and the first sealing resin 24, but in the present embodiment In 4, in order to ensure a higher quality connection, the space above the chip component 26 was filled with the third sealing resin 16 to connect the main substrate 28 and the solid-state imaging device 23 .

The third sealing resin 16 may be not only a thermosetting resin, but also an ultraviolet curable resin that can be cured in a short time, or a heat and ultraviolet curable resin.

The solid-state imaging device of the present disclosure is widely used as a compact solid-state imaging device. For example, it is used as an endoscope solid-state imaging device.

2 Solid-state imaging element 2b Projection electrode 3 Transparent member 5a Taper portion 6 Sealing fixing portion 8b Surface 9 Connection terminal 10 Projection electrode 11 Connection terminal 12 Lead 13 Projection electrode 14 Connection terminal 15 Cable connection terminal 16 Third sealing resin 21 Transparent member 22 Adhesive 23 Solid-state imaging element 23a Light-receiving surface 23b Surface 24 First sealing resin 25 Second sealing resin 26 Chip component 28 Main board 32 Connection terminal

Claims (11)

a solid-state imaging device;
a substrate fixed to the solid-state imaging device with a sealing resin on the surface opposite to the light-receiving surface of the solid-state imaging device;
an outer edge of the substrate viewed from the light-receiving surface side of the solid-state imaging device is contained within an outer edge of the solid-state imaging device;
an outer edge of the sealing resin viewed from the light-receiving surface side of the solid-state imaging element is contained within an outer edge of the solid-state imaging element;
The sealing resin is a laminate of a first sealing resin and a second sealing resin,
Having a first sealing resin on the solid-state imaging device side and a second sealing resin on the substrate side,
The solid-state imaging device according to claim 1, wherein a boundary surface between the first sealing resin and the second sealing resin is inclined from the inside to the outside of the solid-state imaging element as the thickness of the first sealing resin becomes thinner. 2. The solid-state imaging device according to claim 1, wherein spaces for mounting components are formed on the substrate on the left and right sides of the substrate when viewed from the light-receiving surface of the solid-state imaging device. further comprising a transparent member fixed to the light-receiving surface of the solid-state imaging device with an adhesive;
an outer edge of the transparent member viewed from the light-receiving surface side of the solid-state image sensor is contained within an outer edge of the solid-state image sensor;
3. The solid-state imaging device according to claim 1, wherein the outer edge of said adhesive viewed from the light-receiving surface side of said solid-state imaging element is within the outer edge of said solid-state imaging element. 4. The solid-state imaging device according to claim 1, wherein the first sealing resin covers connection electrodes that connect the solid-state imaging element and the substrate. 3. The solid-state imaging device according to claim 2, wherein the second sealing resin seals the component. 6. The solid-state imaging device according to claim 1, wherein said second sealing resin has higher heat dissipation than said first sealing resin. 7. The solid-state imaging device according to claim 1, wherein said second sealing resin is more flexible than said first sealing resin. a solid-state imaging device;
a substrate fixed to the solid-state imaging device with a sealing resin on the surface opposite to the light-receiving surface of the solid-state imaging device;
an outer edge of the substrate viewed from the light-receiving surface side of the solid-state imaging device is contained within an outer edge of the solid-state imaging device;
an outer edge of the sealing resin viewed from the light-receiving surface side of the solid-state imaging element is contained within an outer edge of the solid-state imaging element;
Spaces for mounting components are formed on the substrate on left and right sides when viewed from the light-receiving surface side of the solid-state imaging device,
The sealing resin is a first sealing resin,
A solid-state imaging device comprising a second sealing resin that seals the component without contacting the first sealing resin. The first sealing resin covers a connection electrode that connects the solid-state imaging device and the substrate,
9. The solid-state imaging device according to claim 8, wherein the second sealing resin seals only the component. 10. The solid-state imaging device according to claim 8, wherein the first sealing resin is drum-shaped. 11. The solid-state imaging device according to any one of claims 8 to 10, further comprising a third sealing resin that connects said component and said solid-state imaging device.

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