JPS6366964A - Solid-state image sensing element - Google Patents

Abstract

PURPOSE:To package a solid stage image sensing element in a small size by so providing at least part of a connecting member for electrically connecting a base side bonding pad provided on the front side of a base member to an external electrode provided on the rear side as to be overlapped on the rear surface of a solid state image sensing element chip. CONSTITUTION:A solid stage image sensing element chip 46 is secured to the front side of a base member 44, a bonding pad of the chip 46 is connected by a bonding wire 49 to a bonding pad 51 provided at the front side of the member 44, and an external electrode 31 provided at the rear side of the member 44 is conducted by a connecting member to the pad 51. In such a solid state image sensing element 17, at least part of the connecting member of the part directed toward the rear side of the member 44 from the chip 46 is formed to be overlapped on a part projected from the chip 46. For example, the pad 51 is connected to a copper foil 52, a plating layer 53 formed thereon, and a connecting member, such as a plating layer 55 of the part of a through hole 54 to a metal pin 31 as an external electrode.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a solid-state image sensor packaged in a small size.

[Prior Art] In recent years, various electronic endoscopes using solid-state imaging devices such as charge-coupled devices (CODs) as imaging means have been proposed.

When the above-mentioned solid-state image element is mounted in a narrow-diameter distal end portion inserted into a body cavity, it is desirable to use a solid-state image element as small as possible.

In the solid-state imaging device, a solid-state imaging probe chip is die-bonded to a base member, a bonding pad on the solid-state imaging device chip side and a bonding pad on the base side are wire-bonded, and then sealed with a resin or the like.

Further, this base member is provided with an external electrode for connecting the solid-state image sensor to other electronic components, a PC board, or a signal line, and the base-side bonding pad and the external zK are electrically connected.

The number of base side bonding pads and external electrodes is as follows:
The least number of devices is 6, but this is a solid-state image sensor for black and white image conveyance using a single-phase drive method, and a general 4-phase drive VJ method has 14 to 20 or more. be.

Therefore, in order to miniaturize a solid-state image sensor, it is of course desirable to reduce the pixel size, but it is also important to consider how small the base bonding pad and outer electrode can be made, and how to minimize wasted space. It is important to use them efficiently.

[Problems to be Solved by the Invention] In products using the conventional lead frame method or chip carrier method packaging method, the pitch of the base side bonding pads is as large as 0.6 pitch even if it is narrow; However, there was a drawback in that the package for the solid-state image sensor became larger.

Moreover, when the solid-state image sensor is attached to the base member,
When viewed from above the solid-state image sensor, the bonding pad on the front side of the base and the external electrode on the back side of the base are connected by a connecting member in the area around where the solid-state image sensor chip is attached, so the package with the solid-state image sensor attached is The drawback was that it became very large.

For example, when a solid-state imaging device packaged in this manner is incorporated into the distal end of an endoscope, the distal end becomes thick and causes great pain to the patient during insertion.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a solid-state image sensor that can be packaged in a small size.

[Means and effects for solving the problem] The present invention provides a solid-state imaging device in which a base-side bonding pad provided on the front side of a base member and an external electrode provided on the back side are electrically connected by a connecting member. By providing at least a portion of the connecting member so as to overlap the back of the solid-state image sensor chip, the entire package is miniaturized.

[Example] Hereinafter, the present invention will be specifically described with reference to the drawings.

FIGS. 1 to 5 relate to the first embodiment of the present invention.
The figure shows the solid-state image sensing device of the first embodiment.
Figure 2 is a cross-sectional view showing the vicinity of the solid-state image sensor on the distal end side of the electronic endoscope, and Figure 3 is a line enlarged cross-sectional view taken along line B-B in Figure 2.
Figure 4 is an enlarged cross-sectional view taken along line c-c' in Figure 2.
Is Figure 5 inside the electron? FIG. 3 is a side view showing J2 if.

As shown in FIG. 5, the electronic endoscope 1 has a large-diameter operating section 3 connected to the rear end of an elongated, for example, flexible insertion section 2. As shown in FIG. A connector receiver 4 is provided at the rear end of the operating section 3, and the operating section 3, a light source device, and a video signal processing circuit are connected via a cable 6 having a connector 5 attached to the connector receiver 4. A control device 7 is connected thereto. Furthermore, a color monitor 8 as a display means is connected to the control device 7.

On the distal end side of the insertion portion 2, a rigid distal end portion 9 and a bendable portion 11 adjacent to the distal end portion 9 and capable of bending toward the rear side are sequentially provided. Further, by rotating a bending operation knob 12 provided on the operating section 3, the bending section 11 can be bent in the left-right direction or in the up-down direction. Further, the operation section 3 is provided with an insertion port 13 that communicates with a forceps channel provided in the insertion section 2.

The tip portion 9 is constructed as shown in FIG.

The distal end portion 9 includes a substantially cylindrical distal end component 15 made of a hard insulating material and in which a through hole is formed, and a rigid cylindrical frame 16 fixed to the rear end side of the distal end component 15, for example. A storage section with an inner diameter of 8.511 m is formed, and the solid-state image carrier 17 of the first embodiment and the objective lens system 1 are placed in this storage section.
It stores 8th grade.

The tip 9 is located at a position eccentric to the upper side in FIG. 3 (to the left in FIG. 2) than the center of the tip component 15.
A through hole is formed in the axial direction, and a lens frame 19 to which an objective lens system 18 is attached is fixed to this through hole. At the rear end of this lens frame 19 is a solid-state image element support frame 21.
is fixed, and a solid-state image sensor 17 is mounted inside this support frame 21.
is installed.

Further, a pipe 22 is fixed to a through hole formed adjacent to the objective lens system 18, and a front end of a flexible tube 23 is fixed to the rear end side of the vibrator 22, and the forceps channel 24 is fixed in the hollow part of the pipe 22. is formed.

The outer periphery of the tip component 15 and the outer periphery of the cylindrical frame 16 fixed to the rear end side are covered by a cover tube 25 made of insulating rubber or the like.
For example, the outer diameter is 101nIR. A joint piece 26 that forms a pivot portion and forms a curved portion 11 is attached to the MJM of the cylindrical frame 16 so as to be freely curved at a position 180° opposite to the joint piece 26 .

A square fixed inside the support member 21 -! <On the peak side of the solid-state image sensor 17, there is a metal bottle 3 as an external electrode.
1.31. ..., 31 are provided protrudingly, and these metal bottles 3
1,31. . . , 31, the metal bottles 31.
A circuit board 32 with a through hole 31 passing through is mounted thereon, and a preamplifier, a driver circuit element for reading out signals from the solid state R element 17, etc. are mounted on this circuit board 32.

Each of the metal bins 31 corresponds to each signal line 3 of the bundle shielded wire 33.
4th grade and soldered are connected with etc. A portion near the front end of the east shield wire 33 is fixed to the inner wall of the through hole of the bundle shield wire support member 35 by soldering 36, and the east shield wire support member 35 is fixed to the rear end of the cylindrical frame 21 with a screw or the like. It is fixed.

As shown in FIG. 2, within the cylindrical frame 21, light guides 38.degree. 38 are disposed above and below the solid-state imaging device 17 and the forceps channel 24 disposed on the left and right sides. In addition, an air/water supply channel IF is provided on the upper side of the solid-state image sensor 17.
A channel 39 is formed.

By the way, the solid-state image sensor 17 of the first embodiment has a structure as shown in FIG.

The base member 44 is formed of three layers: a base material 41, an insulating layer 42 fixed to the upper surface (surface) of this base material 41, and an insulating layer 43 further fixed to the upper surface of this insulating layer 42. A header 45 is provided on the top surface of the FA43 by printing gold alloy, and on the top surface of this header 45, for example, 3.4NRX
A solid-state image sensor chip 46 with a size of 3.2 mm is fixed. The base material 41 is made of glass epoxy resin or ceramic material. Further, the insulating layers 42 and 43 are also made of resin or ceramic material. The header 45 serves as a stage for die-bonding a solid-state image sensor chip 46.

As shown in FIG. 2, in the solid-state image sensor chip 46, a square image area 47 of 2.811111 x 2.8M is formed in the center excluding the periphery. For example, fourteen chip-side bonding pads 48 are provided. still,
The image area 47 has 384×384 pixels in the horizontal and vertical directions, that is, approximately 150,000 pixels in total.

The solid-state image pickup device depth 46 uses a four-phase driving force type field accumulation type interline COD, and a color filter (as shown) in the shape of a mirror is attached to the upper surface of this image area 47.

The dimensions of each chip-side bonding pad 48 are, for example, 0.11MR x 0.11m, and the pad is 0.2m.
Each chip-side bonding pad 48 is connected to a base-side bonding pad 51 by a bonding wire 49.

This bonding wire 49 uses, for example, a 25μ gold wire or aluminum wire.

As shown in FIG. 1 or 4, the base-side bonding pad 51 is connected via connecting members such as a copper foil 52, a metal plate 11ff 153 plated on the copper foil 52, and a plating layer 55 in the through hole 54 portion. and is connected to a metal bottle 31 as an external electrode.

Of the 14 base-side bonding pads 51, 10 of them are connected to the metal bottle 31 through the back side of the solid-state image sensor chip 4G, as a typical example is shown in FIG. Four of them are connected to the metal bin 31 through the side surface of the base member 44, a typical example of which is shown in FIG. In addition, the base side bonding pad 5
1 has a width of 0.15 mm and a pitch of 0.25 #.

The copper foil 52 forming the connecting member is coated with the contact agent 56.
An unnecessary portion is removed from the insulating layer 42 or the base material 41 with one side entirely adhered by a photoresist method, etc.
It is formed into a predetermined wiring pattern as shown in FIGS. 1 and 4.

The copper foil 52 with the wiring pattern is coated with a gold-plated plating layer 53 after electrolytic copper plating.

Further, the plated layer 55 in the through hole 54 portion is formed by electroless copper plating, and its surface is similar to the plated layer 53 described above.
covered with. Plating layer 55 inside this through hole 54
The outer diameter is, for example, 0.4φ.

Seven of the fourteen metal bottles 31 are connected to the circuit board 32, and the other seven are directly connected to the single wire in the bundled shielded wire 33. The other single wires and shielded wires of this bundle of shielded wires 33 are connected to the circuit board 32.

The metal bottle 31 is made of Kovar or the like, and is brazed to the plated Fi453 portion on the back side of the base member 44 with a metal rod having an outer diameter of, for example, 0.3φ. Metal bottle 31. . . . , 31 is formed with long legs and short legs to make it easier to attach the circuit board 32 as shown in FIG. This allows for easy connection to the signal line 34.

Although the plating layer 53 in the through hole 54 has a hollow cylindrical shape, it may be filled in a cylindrical shape. Further, both ends of the through hole 54 may be closed,
As shown in FIG. 1, a cavity may be formed inside. On the back side of the base member 44, the through hole 54 is filled with the plating layer 53, and it is better to form a pad for brazing the metal bottle 31 on the axis of the through hole 54.
This is convenient because the degree of freedom in moving the metal bottle 31 can be increased.

In this first embodiment, as shown in FIG. 2, when connecting to the metal bottle 31 through only the side surface of the base member 44, the width of the arrangement pattern portion is wide compared to the width of the base-side bonding pad 51. Therefore, the dimensions of the side surfaces of the base member 44 must be increased;
As shown in the figure, means for connecting to the metal bottle 31 through the arrangement pattern portion and through-hole portion on the back side of the solid-state image sensor chip 46 is also provided.
4 can be reduced in size. Further, since the arrangement pattern portion can be arranged three-dimensionally by providing it on the laminated insulating layer 42 and insulating layer 43, wiring can be performed using a small base member 44. Furthermore, the solid-state Wi image device can also be miniaturized by providing the metal bottle 31 opposite to the back side of the solid-state image sensor chip 46.

After the bonding wire 49 is attached, the surface side of the solid-state image element chip 46 is covered with a transparent resin 6 such as epoxy resin.
1 is sealed. A cover glass 62 is attached to the front surface of this translucent resin 61.

In the electronic endoscope 1 configured in this manner, the solid-state image sensor 17, which is a package of the solid-state image sensor chip 46, is formed in a smaller size. That is, the solid-state image sensor chip 46 is die-bonded to the base member 44 via the header 45, and the bonding pad 48 on the chip side and the bonding pad 5 on the base side
1 is connected. Thus, a continuous member that electrically connects this base-side bonding pad 51 and the metal bottle 31 as an external electrode provided on the back side of the base member 44 is brought into conduction along the side surface of the base member 44. In addition, the base member 44 is made multilayered to form four three-dimensional wiring patterns, and most of the wiring patterns are formed on the back side of the solid-state R image element chip 46, thereby reducing the size. ing.

For example, the solid-state image sensor 17 of the first embodiment has a package size of 4.5 s*×3.8 m+, which is very compact. Therefore, when the electronic endoscope 1 is formed by storing the first embodiment in the distal end of the endoscope, the dimensions of the distal end 9 can be reduced, and the pain caused to the patient during insertion can be significantly reduced. . Furthermore, since the device can be inserted into small insertion points, the range of use can be expanded.

In the first embodiment, a light-transmitting glass such as the cover glass 62 is attached, but an infrared cut filter or a moire prevention filter may be used.

Further, the metal bottle 31 is brazed to the plated layer 53 on the back side of the base member 44, but it is also possible to print (metallize) a gold alloy on the back side of the base member 44 and braze it thereon. .

FIG. 6 shows a sectional view of a solid-state imaging device 71 according to a second embodiment of the present invention.

Also in this second embodiment, a base material 41, an insulating layer 42 on the upper surface of this base material 41, an insulating layer 43 on the upper surface of this insulating layer 42,
The base member 44 is then formed.

Therefore, the header 45 formed on the top surface of this cutout 1143
On the top surface of the solid iIs! An element chip 46 is attached. A color filter array 72 is attached to the surface of the solid-state image sensor chip 46 on which the image area is formed, and the front surface of the color filter array 72 is protected by a cover glass 62.

By the way, in this embodiment C, the wiring pattern is not formed by a photoresist method, but is formed by printing molding.

The base material 41 has a metal bottle 7 as an external electrode facing toward the back side.
3 are buried. Further, a conductor 74a made of a gold alloy is printed and molded on the surface of this base material 41, and this conductor 74a is insulated F,! after being printed and molded. ! i 42 is formed into a predetermined shape. Thereafter, a conductor 74b made of a gold alloy is further formed by printing.

Further, after this printing, an insulating layer 43 is laminated in a predetermined pattern. A header 45 is attached to the upper surface of this insulating layer 43, and a conductor 74c is printed and formed to be electrically connected to the conductor 74b and whose upper surface becomes the base-side bonding pad 75. This conductor 74C is formed to have a thickness so that it is flush with the top surface of the header 45. Therefore, the portion where the header 45 and the conductor 74C are not formed is further covered with the insulating layer 7.
6 is formed.

The chip-side bonding pads of the solid-state image sensor chip 46 die-bonded to the upper surface of the header 45 are connected to the base-side bonding pads 75 by bonding wires 49 . Solid-state imaging differential 146 such as the space of the recess where this bonding wire 49 is attached
The periphery is sealed with resin 77.

In the second embodiment, all the external electrodes are made of metal bottles 7.
3, for example, the east shield ll1 in Figure 1.
33 is directly connected to the signal line 34, a recessed land 78 is formed into which the center conductor 34a of the signal line 34 can be inserted and connected by soldering or the like. this land 7
8 is a gold alloy conductor 74d which is printed and formed like the other conductors 748 and the like.

According to the second embodiment, the connecting member that electrically connects the base-side bonding pad 75 and the external electrode can be formed by printing, so that the manufacturing process can be simplified and the manufacturing process can be shortened.

The ability to reduce the size is the same as in the first embodiment.

Note that in the second embodiment, the conductor 34a is attached to the land 78.
Alternatively, a structure may be adopted in which a coated signal tiA34 or the like is attached to form an external TX pole together with the metal bottle 73.

FIG. 7 shows a solid-state image sensor 81 according to a third practical example of the present invention.

This embodiment uses a multi-wire method.

Insulated coated wires 83. ..., 83 are embedded in solid resin layers 84, 85.

Each of the insulated wires 83 has copper 1183A coated with an insulating sheath 183B such as polyimide. It can be placed parallel to the plate surface of H'A41, or it can be placed in the thickness direction of the base material 41, and the surrounding area can be solidified with a solid resin layer 84°85, or reinforced resin 86T: fixed. There is.

In addition, the insulating coated wire 83 is passed through the plated portion 88 attached to the upper surface of the overlay 87 via the contact agent 56 by passing through the plated layer 55 of the through ball 54 that penetrates the base material 41. It is. A plating resist 89 is formed between adjacent plating parts 88 and 88. The plated portion 88 extends to the end (the right end in FIG. 7) of the solid-state image element chip 46 close to the chip-side bonding pad, and a conductor 74 is provided on the top thereof by printing molding or the like. One end of the bonding wire 49 is attached to the exposed base-side bonding pad portion of the conductor 74. The portion of the conductor 74 other than the base side bonding pad portion is covered with an insulating layer 43.
A solid-state image sensor chip 46 is die-bonded to the top surface of the device via a header 45.

In this embodiment, the insulated wire 83 serves both as a part of the connecting member and as an external electrode protruding to the back side of the solid-state image sensor 81, and the end part protruding to the real side is Connected to other electronic components, PC boards, and bundled shielded wires. Copper wire 83 in the insulation coated wire 83
A can be used, for example, with a diameter of 0° and 15φ.

Note that a mesh resist 89 is also provided on the lower surface (back surface) of the solid resin layer 85 on the lower side of the base material 41.

The rest of the structure is almost the same as that of the second embodiment.

FIG. 8 does not show the solid state image carrier 91 of the fourth embodiment of the present invention.

In this fourth embodiment, a flexible printed circuit board 92 is used to form a base side bonding pad 1593, a connecting member, and an external electrode.

The flexible substrate 92 includes a base film 94,
A gold-plated copper foil pattern 96 is attached to the upper surface of this base film 94 using an adhesive 95. This copper foil pattern 96 is formed, for example, in the shape of a short shelf, and the surface side of the copper foil pattern 96 is fixed to the back surface of the insulating layer 43. At this time, the base-side bonding pad 9 is located at the part protruding from the insulating layer 43 to the right side.
3 is formed.

The flexible printed circuit board 92 is bent in the middle,
The bent part is reinforced with a reinforcing plate 97, and the back side of the flexible printed circuit board 92 is also reinforced with a reinforcing plate 98, and is fixed by being covered with molded resin 99.

In this embodiment, a compact solid-state image sensor 91 can be formed very easily.

FIG. 9 shows a fifth embodiment of the invention.

In this embodiment, a base member 101 has a structure similar to that of the second embodiment shown in FIG. 6, for example.

In this base member 101, a conductor 102 is formed by printing or the like on the back side of the base material 41 in the base member 44 of FIG.
The conductor 102 forms a bonding pad 103 and a wiring pattern that communicates with the bonding pad 103.

Further, an insulating layer 104 is provided on the back surface of this base material 41, and an integrated circuit chip 105 is attached to the back surface directly or by providing a header (not shown). This integrated circuit chip 105 is an integrated circuit that is necessary for operating a solid-state image device (chip), such as a preamplifier and a drive circuit. The bonding pad of this integrated circuit deep 105 is electrically connected to the bonding pad 103 portion by a bonding wire ψ106.

This bonding pad 103 is electrically connected to the base-side bonding pad connected to the solid-state image device chip 46 by the bonding wire 49 via a connecting means as in the embodiment described above, or is connected to the external electrode 31. I'm doing it.

Incidentally, the periphery of the integrated circuit chip 105 to which the bonding wire 106 is attached is sealed with a resin 107.

In this fifth embodiment, when operating the solid-state R image element, the peripheral circuit parts that are required are also integrally formed as integrated circuits, so that the size can be reduced.

[Effects of the Invention] As described above, according to the present invention, in a solid-state R image element in which the base-side bonding pad provided on the front side of the base member and the external electrode provided on the back side are electrically connected by the connecting member. Since at least a portion of the connecting member is provided so as to overlap the back side of the solid-state image sensor chip, the solid-state image sensor can be packaged in a small size.

[Brief explanation of the drawing]

FIGS. 1 to 5 relate to the first embodiment of the present invention.
The figure is a sectional view showing the solid-state image sensor of the first embodiment, FIG. 2 is a sectional view showing the tip of an electronic endoscope in which the first embodiment is formed, and FIG. ' line cross-sectional view, Figure 4 is the 2nd
5 is a side view showing the entire electronic endoscope, FIG. 6 is a sectional view showing the second embodiment of the present invention, and FIG. 7 is a sectional view showing the third embodiment of the present invention. FIG. 8 is a cross-sectional view showing a fourth embodiment of the present invention, and FIG. 9 is a cross-sectional view showing a fifth embodiment of the present invention. 1... Electronic endoscope 9... Tip part 17...
Solid-state image sensor 31...Kinminbin 41...Base material
42.43... Insulating layer 44... Base member 4G... Solid-state image sensor chip 49... Bonding wire 51... Base side bonding pad 52... uA
Foil 53.55 Plating layer 54 Through hole 56 Adhesive Figure 4 Figure 5 Figure 7

Claims (1)

[Claims] A solid-state image sensor chip is fixedly provided on the front side of the base member, and a bonding pad of the solid-state image sensor chip and a bonding pad provided on the front side of the base member are connected with a bonding wire, and In a solid-state imaging device in which an external electrode provided on the back side of the member and a base-side bonding pad are electrically connected by a connecting member, at least a portion of the connecting member from the solid-state imaging device chip side toward the back side of the base member A solid-state image sensor, characterized in that the solid-state image sensor chip is formed so as to overlap a projected portion.