JP2510198B2 - Semiconductor device - Google Patents

Description

Description: [Industrial field of application] The present invention relates to an improvement in the assembly structure of a microminiature semiconductor device used for an endoscope or the like.

[Problems to be Solved by Prior Art and Invention] In recent years, various electronic endoscopes using a solid-state imaging chip such as a charge-coupled device (CCD) as an imaging means have been proposed.

These solid-state image pickup chips are housed in a package and incorporated in the tip of the insertion part, but it is necessary to reduce the outer diameter of the solid-state image pickup device in order to reduce the pain of the patient. It is important how to reduce the size.

On the other hand, Japanese Laid-Open Patent Publication No. 61-236280 discloses a person who has a groove formed in the center of a base member, a solid-state image sensor is arranged in the groove, and a solid material is sealed with a sealing material. There is.

By the way, since a base member formed of a ceramic substrate or the like is likely to have burrs in this manufacturing process, the dimensional accuracy including burrs becomes ± 0.15 mm. Furthermore,
The corners are liable to chip, and when the thickness is 0.6 mm, it is inevitable that a CO.3 chipping will occur. Therefore, in order to prevent the semiconductor chip from protruding from the base member, it is necessary to enlarge the base member in advance to a size that allows for burrs and chips, and as a result, the semiconductor device is about 0.3 mm long and wide. It was

Further, the plastic substrate is also likely to have burrs and chips at the ends, and in the injection-molded product, the gate portion becomes a protrusion.
Similarly, the glass substrate also has a problem that it is easily chipped.

[Object of the Invention] The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a microminiaturized semiconductor device having high dimensional accuracy without being affected by burrs and chips of the base member. To aim.

[Means and Actions for Solving Problems] According to the present invention, at least a die bonding pad member, which is slightly larger than a semiconductor chip, is provided on a base member, at least a part of which protrudes from a side end surface of the base member or a side surface of the base member. The semiconductor chip is exposed from the base member by being superposed on the surface of the base member such that the end faces coincide with each other, and at least a part of the side end face of the die bonding pad member forms a part of the side end face of the semiconductor device. This can be prevented, the dimensional accuracy of the semiconductor device can be improved, and the size can be reduced as much as possible.

[Embodiment] FIGS. 1 and 2 relate to the first embodiment. FIG. 1 (a) is a front view of a semiconductor device, and FIG. 1 (b) is AA of FIG. 1 (a). 1 '(c) is a sectional view taken along line BB of FIG. 1 (a). FIG. 1 (d) is a front view of a die bonding member, and FIG. 2 is a specific example of this embodiment. FIG. 4 is a cross-sectional view of the distal end portion of the endoscope showing FIG.

In FIG. 2, the distal end portion 2 of the elongated insertion portion 1 of the endoscope is shown.
Includes a substantially columnar tip body 3 made of a material such as metal. The distal end body 3 is formed with an observation through hole 4 penetrating in the longitudinal direction with respect to the insertion portion and an illumination through hole (not shown).

An objective lens system 6 is fitted in and fixed to the observation through hole 4, and a solid-state image pickup device 7 is provided at the image forming position of the objective lens system 6 behind the observation lens. Positioned by 8 and mounted.

A lead portion 8 is fixed to the rear end surface of the solid-state image pickup device 7, and a signal line 9 inserted through the insertion portion 1 is soldered.

A flexible tube 11 made of rubber or the like is externally fitted and fixed to the rear end portion of the tip end body 3.

The solid-state imaging device 7 is configured as shown in FIG.

An image area 13 is formed on the front surface of the solid-state imaging chip 12 as a semiconductor chip.
A chip-side bonding pad 14 is provided on the slightly widened side in the periphery of.

On the back surface of the solid-state imaging chip 12, the solid-state imaging chip 12
Slightly larger, eg 0.1 mm thick with gold plating
Die bonding pad member 16 such as Kovar plate,
By aligning the side end surface of the solid-state imaging chip 12 on the bonding pad side and the side end surface of the die bonding pad member 16,
For example, it is die-bonded with silver paste.

On the surface of the die bonding pad member 16, for example, as shown in FIG. 1D, a frame-shaped index 10 having substantially the same shape and size as the outer shape of the solid-state imaging chip 12 is provided. By fixing the solid-state imaging chip 12 inside this index 10, the image area
13 positionings can be performed.

The index 10 may be a through hole formed by half etching or etching, or may be formed by printing or the like.

The die bonding pad member 16 is fixed to the multilayer ceramic substrate 17 as a base member formed of ceramic such as alumina by silver brazing.

The multilayer ceramic substrate 17 is a substantially flat plate, and the front surface thereof is formed in a step shape by the step portion 18. The die-attach portion 20 which is the step-shaped thin portion, which is the thin portion, has three layers, and the thickness is 0.6 mm, and the pad portion 15, which is the thick portion, is 1.2 mm.

Further, the corner portion 15a of the pad portion 15 is chamfered and formed so that the diagonal dimension of the multilayer ceramic substrate 17 is reduced.

The solid-state imaging chip 12 and die bonding pad member
The end face that coincides with 16 abuts on the step portion 18, and the other end face slightly protrudes or coincides with the end face of the multilayer ceramic substrate 17.

The die bonding pad member 16 is fixed to the solid-state imaging chip 12 so as to be electrically connected to the GND terminal (or Pwel terminal in some cases) as the ground of the solid-state imaging chip 12.

The chip side bonding pad 14 is connected to a substrate side bonding pad 19 provided on the front surface of the pad portion 15 by a bonding wire 21.

By the through holes 22 provided in the board-side bonding pad 19 and the internal wiring of the multilayer ceramic board 17,
It is connected to a flat land (not shown) provided on the back surface of the multilayer ceramic substrate 17.

The lead portion 8 having a flange 23 at one end is fixed to the flat land (not shown).

The front side of the die bonding pad member 16 on which the solid-state imaging chip 12 is fixed is a sealing material such as a transparent epoxy resin.
It is sealed by 24, and the side end surface of the sealing material 24 forms the same surface as the side end surface of the die bonding pad member 16.

By the way, the die bonding pad member 16 has an outer shape larger than the solid-state imaging chip 12 by 0.15 mm on one side, and the tolerance of the width dimension W is from 0 mm to -0.006 mm. On the other hand, the tolerance of the width W of the multilayer ceramic substrate 17 is −0.006 mm to −0.36 mm, and the outer peripheral surface of the die bonding pad member 16 slightly projects from the outer peripheral surface of the multilayer ceramic substrate 17, or It is supposed to match. Therefore, at least a part of the side end surface of the die bonding pad member 16 forms a part of the side end surface of the solid-state imaging device 7.

Although the lead portion 8 having the flange 23 is provided on the back surface of the multilayer ceramic substrate 17, the shape of the external terminal is not limited to this, and a PGA (pinglit array), a leads chip carrier, or the like may be used.

Further, the die bonding pad member 16 may not be a Kovar plate, and may be, for example, a brass plate or a phosphor bronze plate plated with nickel or gold.

Further, the side end portion of the die bonding pad member 16 may be exposed or may be thinly covered with the sealing material 24.

Although the multilayer ceramic substrate 17 is used as the base member, the material is not limited to ceramics, and may be glass or plastic. If the solid-state imaging device is not used, the encapsulating material 24 may not be transparent or may be low-melting glass. Good.

According to the present embodiment, the outer shape of the die bonding pad member is made slightly larger so that the solid-state imaging chip can be easily sealed, and the outer shape of the encapsulating material matches the outer shape of the multilayer ceramic substrate with good dimensional accuracy. Since it is formed as described above, it is possible to improve the dimensional accuracy of the solid-state imaging device,
Moreover, the size of the solid-state imaging device can be reduced as much as possible.

Further, since the dimensional accuracy is high, the sealing material can be molded using a mold such as injection molding.

FIG. 3 shows a second embodiment, FIG. 3 (a) is a side view in the CC ′ direction of FIG. 3 (b), FIG. 3 (b) is a front view of the solid-state imaging device, and FIG. (C) is DD 'of FIG. 3 (b).
FIG.

On the back surface of the solid-state imaging chip 12, a die bonding pad member 26, which is slightly larger than the solid-state imaging chip 12 and is, for example, a 0.1 mm thick Kovar plate plated with gold, is provided on the bonding pad side of the solid-state imaging chip 12. The end face and the side end face of the die bonding pad member 26 are aligned with each other and die-bonded with, for example, a silver paste.

The die bonding pad member 26 is fixed by silver brazing to a multi-layer ceramic substrate 27 serving as a base member formed of ceramic such as alumina.

The multilayer ceramic substrate 27 is a substantially flat plate, and the front surface thereof is formed in a step shape by a step portion 28. In addition, the corner portion 29 that forms the outer shape is chamfered to obtain a multilayer ceramic substrate.
The diagonal dimension of 27 is designed to be small.

The solid-state imaging chip 12 and die bonding pad member
The end portion which coincides with 26 is fixed to the multilayer ceramic substrate 27 so as to contact the step portion 28, and the GND lead portion 31 is provided at the end portion of the other die bonding pad member 26 with the multilayer ceramic substrate. It is extended to the back side of 27.

Since the die bonding pad member 26 is fixed to the solid-state imaging chip 12, the die-bonding pad member 26 is electrically connected to the GND terminal (or Pwel terminal in some cases) as the ground of the solid-state imaging chip 12. Noise can be prevented by connecting the use lead portion 31 to a shield member (not shown).

A chip side bonding pad (not shown) provided on one side of the solid-state imaging chip 12 is connected to a board side bonding pad (not shown) provided on the multilayer ceramic substrate 27 by a bonding wire 33.

The board-side bonding pad 32 (not shown) is connected to a flat land (not shown) provided on the back surface of the multilayer ceramic substrate 27 by internal wiring.

The front of the image area 13 of the solid-state imaging chip 12 is
For example, it is sealed with a sealing material 24 such as a transparent epoxy resin, and the periphery of the solid-state imaging chip 12 is sealed with a sealing material 37 such as an insulating resin.

With the configuration of this embodiment, the heat generated by the solid-state imaging chip 12 can be released from the GND lead portion 31.

 Other configurations and effects are similar to those of the first embodiment.

FIG. 4 shows a third embodiment, FIG. 4 (a) is a front view of the solid-state imaging device, and FIG. 4 (b) is EE ′ of FIG. 4 (a).
FIG.

The back surface of the solid-state imaging chip 12 has an outer shape that is slightly larger than the solid-state imaging chip 12, and further slightly protrudes from the side end surface of the multilayer ceramic substrate 39, or has side end surfaces aligned with each other, and a cutout portion on one side. A die bonding pad member 38 such as a Kovar plate plated with gold, which is provided with 40, makes the side end of the solid-state imaging chip 12 and the end face of the cutout 40 coincide with each other, and the other side end. Are fixed so as to project from the solid-state imaging chip 12.

The multilayer ceramic substrate 39 has a step 41,
The solid-state imaging chip 12 and the die-bonding pad member 38 are fixed to 41 so that the corresponding side end surfaces thereof come into contact with each other.

The front surface of the solid-state imaging chip 12 and the side end surface of the multilayer ceramic substrate 39 are sealed with a sealing material 24 such as a transparent epoxy resin, and the end surface of the die bonding pad member 38 protruding from the multilayer ceramic substrate 39 is sealed. It constitutes a part of the side end surface formed by the stopper 24.

 Other configurations and effects are similar to those of the first embodiment.

FIG. 5 shows a fourth embodiment, FIG. 5 (a) is a front view of the solid-state imaging device, and FIG. 5 (b) is FF ′ of FIG. 5 (a).
FIG.

The back surface of the solid-state imaging chip 12 is slightly larger than the solid-state imaging chip 12, and the GND bonding pad section 4 is provided at one corner.
A die bonding pad member 43 having 2 is fixed.

On the back surface of the die bonding pad member 43, a multilayer ceramic substrate 44 having a contour which is slightly retracted from the side end surface of the die bonding pad member 43 or whose side end surfaces are aligned is fixed so that the bonding pad portion 46 is exposed. It is set up.

The bonding pad portion 46 is provided with a substrate-side bonding pad (not shown) and is connected to a chip-side bonding pad (not shown) by a bonding wire 47. The GND terminal of the solid-state imaging chip 12 is connected to the GND bonding pad portion 42 by a bonding wire 47 so as to be electrically connected to the die bonding pad member 43.

The board-side bonding pad (not shown) is connected to the lead portion 48 having a flange provided on the back surface of the multilayer ceramic board 44 by internal wiring.

 Other configurations and effects are similar to those of the first embodiment.

FIG. 6 is a sectional view of the solid-state imaging device showing the fifth embodiment.

On the back surface of the solid-state imaging chip 12, a die bonding pad member 51 having an outer shape slightly larger than that of the solid-state imaging chip 12 and having the solid-state imaging chip 12 fitted in the recess 49 is fixedly provided.

Further, a multilayer ceramic substrate 50 having a step portion 52 is fixedly provided on the back surface of the die bonding pad member 51, and the step portion 52 contacts one side end surface of the die bonding pad member 51, and the other side. The side end surface of the is slightly projected from or coincides with the side end surface of the multilayer ceramic substrate 50.

Image area provided in front of the solid-state imaging chip 12
A sealing material such as a transparent epoxy resin is provided on the
Further, the periphery of the sealing material 24 is sealed with an insulating sealing material 37.

By configuring as in this embodiment, the solid-state imaging chip 12 can be easily positioned.

The recess 49 may be formed by half etching, or may be formed by providing a frame member on a flat plate.

 Other configurations and effects are similar to those of the first embodiment.

FIG. 7 shows a sixth embodiment, FIG. 7 (a) is a side view along the line GG ′ in FIG. 7 (b), and FIG. 7 (b) is a front view of a die bonding pad member.

On the front surface of the multilayer ceramic substrate 53, a first die bonding pad member 54 having an outer shape that slightly projects from the side end surface of the multilayer ceramic substrate 53 or matches the side end surface.
Is fixed. Further, on the upper surface of the first die bonding pad member 54, a second die bonding pad member 56 having the same shape and size as the solid-state imaging chip 12 and die-bonding the solid-state imaging chip 12 is fixedly provided. ing.

By configuring as in this embodiment, the first die bonding pad member 54 can reinforce the multilayer ceramic substrate 53, and the second die bonding pad member 56 facilitates positioning of the solid-state imaging chip. To be able to do.

 Other configurations and effects are similar to those of the first embodiment.

8 to 9 are modifications of the first embodiment, and FIG. 8 (a) is a side view taken along line H-H 'in FIG. 8 (b), and FIG.
FIG. 9B is a front view of the die bonding pad member,
The figure is a front view of another die bonding pad member.

In FIG. 8, on the upper surface of the die bonding member 58 having a contour slightly protruding from the side end surface of the multilayer ceramic substrate 57 fixedly provided on the multilayer ceramic substrate 57 or having the side end surfaces aligned with each other, a solid body (not shown) is formed. The indexes 59 that match the four corners and the four sides of the imaging chip are provided by half etching.

By thus providing the index 59, the solid-state imaging chip can be easily positioned.

In FIG. 9, the solid-state imaging is provided on the upper surface of the die bonding pad member 62 that is fixedly provided on the multilayer ceramic substrate 61 and has an outer shape that slightly protrudes from the side end surface of the multilayer ceramic substrate 61 or that has the same side end surface. An index 63 that matches the outer circumference of the chip is provided by half etching.

By thus providing the index 63, the solid-state imaging chip can be easily positioned.

Note that the present invention is not limited to the solid-state imaging device, but includes a logic element, etc.
The content of the semiconductor does not matter. Further, it goes without saying that the invention can be applied to optical electronic devices such as general micro TVs and pipe cameras, and micro devices such as watches. In particular, since the size of the element is severely restricted in the width direction, the advantage is great when it is impossible to mount the element side by side with another element by chip-on-board or hybridization.

[Effects of the Invention] As described above, according to the present invention, there is an effect that the dimensional accuracy is high and the size can be reduced as much as possible without being affected by burrs and chips of the base member.

[Brief description of drawings]

1 and 2 relate to the first embodiment, and FIG. 1 (a)
1A is a front view of the semiconductor device, FIG. 1B is a sectional view taken along the line AA ′ of FIG. 1A, and FIG. 1C is B of FIG. 1A.
-B 'direction sectional view, FIG. 1 (d) is a front view of a die bonding member, FIG. 2 is a sectional view of an endoscope tip portion showing a specific example of the present embodiment, and FIG. 3 is a second embodiment. FIG. 3 (a) is a side view in the CC ′ direction of FIG. 3 (b), FIG. 3 (b) is a front view of the solid-state imaging device, and FIG. 3 (c) is FIG. FIG. 4B shows a third embodiment of the present invention, FIG. 4A is a front view of the solid-state imaging device, and FIG. 4B is a front view of FIG. 4A. FIG. 5 shows a fourth embodiment, FIG. 5 (a) is a front view of the solid-state image pickup device, and FIG. 5 (b) is FF in FIG. 5 (a). ′ Direction sectional view, FIG. 6 is a sectional view of a solid-state imaging device showing a fifth embodiment,
FIG. 7 shows a sixth embodiment, FIG. 7 (a) is a side view along the line GG ′ in FIG. 7 (b), FIG. 7 (b) is a front view of a die bonding pad member, and FIG. Figures 9 to 9 are modifications of the first embodiment, and Figure 8 (a) is Figure 8 (b).
FIG. 8B is a front view of the die bonding pad member, and FIG. 9 is a front view of another die bonding pad member. 7 ... Solid-state imaging device 12 ... Solid-state imaging chip 16 ... Die bonding pad member 17 ... Multilayer ceramic substrate

Claims (1)

(57) [Claims] 1. A die bonding pad having a base member and at least a part of a side end face thereof, which is fixed to the base member by contacting with the base member, protrudes from the side end face of the base member or coincides with the side end face of the base member. A member, a semiconductor chip smaller than the die bonding pad member, which is die-bonded to the surface of the die bonding pad member opposite to the base member, and a sealing material for sealing the semiconductor chip. At least a part of a side end surface of the die bonding pad member which is protruded from a side end surface of the base member or coincides with the side end surface of the base member forms a part of a side end surface of the semiconductor device. Semiconductor device.