JP2010080577A - Semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device which can reduce a mounting area of a semiconductor package and can reduce the width of a printed board in compliance with the width of a mounting surface. <P>SOLUTION: A package substrate 30 mounted with a semiconductor chip seals the semiconductor chip inside therein and has first junction electrodes 32 arranged on the backside 30a and second junction electrodes 33 arranged on a pair of side faces 30b opposite to each other in the X direction. A printed board 28 has first land electrodes 40 arranged on the top face 28a and second land electrodes 41 arranged on a pair of side faces 28b opposite to each other in the X direction. The package substrate 30 and the printed board 28 have nearly the same width in the X direction. The first junction electrodes 32 and the first land electrodes 40 are electrically and mechanically joined with solder balls 34, and the second junction electrodes 33 and the second land electrodes 41 are electrically and mechanically joined with a solder paste 50. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a semiconductor device in which a semiconductor package such as a solid-state image sensor is mounted on a printed board.

  Conventionally, a digital camera that incorporates a zoom function by using a mirror or prism to bend the optical axis by 90 degrees to reduce the thickness of the housing and to take advantage of the extra length generated in the optical axis direction. It is known (see, for example, Patent Document 1).

  A solid-state imaging device such as a CCD image sensor or a CMOS image sensor is incorporated in the housing of such a digital camera. The solid-state image sensor is usually mounted on a printed circuit board in a state packaged with a ceramic package or the like.

In recent digital cameras, the use of a CMOS image sensor, which is superior in terms of cost and power consumption, as a solid-state imaging device compared to a CCD image sensor is increasing.
JP-A-8-130702

  Since CMOS image sensors usually have more external terminals than CCD image sensors, they can be mounted by using a ball grid array (BGA) type package in which ball-shaped external terminals are arranged in a two-dimensional array on the back surface. The area is reduced.

  However, when using a solid imaging device for the bending optical system having a large number of external terminals, the width of the package and the printed circuit board in the thickness direction of the casing is It is preferably as small as possible and further improvements are required. This is not limited to the CMOS image sensor, and the CCD image sensor preferably has the above improvement when the number of external terminals is large. Further, the present invention is not limited to a solid-state imaging device, and the same applies to the case where an electronic apparatus including a semiconductor device in which another semiconductor package is mounted on a printed board is to be thinned.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a semiconductor device capable of reducing the mounting area of the semiconductor package and reducing the width of the printed board in accordance with the width of the mounting surface. And

  In order to achieve the above object, in the semiconductor device of the present invention, the first bonding electrode is disposed on the back surface, the second bonding electrode is disposed on a pair of side surfaces facing in one direction, and the semiconductor chip is sealed inside. A substantially rectangular parallelepiped semiconductor package, a first land electrode is disposed on an upper surface facing the back surface, and a second land electrode is disposed on each of a pair of side surfaces facing the one direction, and the semiconductor package with respect to the one direction. Between the first junction electrode and the first land electrode and between the second junction electrode and the second land electrode electrically and mechanically. And a conductive bonding material to be bonded.

  The second land electrode preferably has a cross-sectional through-hole structure.

  The semiconductor package is preferably made of a low-temperature co-fired ceramic. The semiconductor package is preferably made of a resin.

  Moreover, it is preferable that a solder ball is formed on the first bonding electrode as a conductive bonding material.

  The first and second bonding electrodes are preferably bonded to the first and second land electrodes via a conductive bonding material formed by a screen printing method.

  According to the present invention, the mounting area can be reduced by providing the second bonding electrode on the semiconductor package, and the printed circuit board can be adjusted to the width of the mounting surface by providing the second land electrode on the printed circuit board. The width of can be reduced.

  In FIG. 1, a light receiving window 12, a finder window 13, and a flash light emitting unit 14 are arranged on the entire surface of the housing 11 of the digital camera 10 in order from the right side to the left side. The casing 11 has a rectangular parallelepiped shape that is flat in the front-rear direction (X direction), and a bending optical system 15 that forms an image by bending the subject light incident from the light receiving window 12 is provided therein.

  The bending optical system 15 is provided in the casing 11 in a state where the bending optical system 15 stands along the right side wall of the casing 11. As shown in FIG. 2, the bending optical system 15 includes an objective lens 21 exposed from the finder window 13, a prism 22 provided behind the objective lens 21, and a lower part of the prism 22. Zoom lenses 23, 24, a shutter unit 25 disposed between the two zoom lenses 23, 24, and a focus lens 26 disposed below the zoom lenses 23, 24.

  Further, below the focus lens 26, a solid-state imaging device 27 made of a CMOS image sensor is provided. The solid-state image sensor 27 is mounted on a printed circuit board 28 disposed therebelow.

  The light beam L of the subject light incident from the objective lens 21 is bent downward by the prism 22 and travels toward the bottom surface of the housing 11. The light beam L emitted from the prism 22 enters the imaging unit of the solid-state imaging device 27 through the zoom lenses 23 and 24, the shutter unit 25, and the focus lens 26. The solid-state imaging device 27 receives the subject light imaged by the focus lens 26 and outputs an image signal corresponding to the received light amount.

  Although not shown in the figure, the printed circuit board 28 includes a drive circuit that drives the solid-state image sensor 27, a signal processing circuit that processes image signals output from the solid-state image sensor 27, a capacitor, a resistor, and the like. The electronic parts are mounted by the surface mounting method.

  In FIG. 3, a solid-state image sensor 27 is a semiconductor package in which a semiconductor chip (not shown) on which a CMOS image sensor is formed is enclosed by a package substrate 30 and a cover glass 31, and is a rectangular parallelepiped shape flattened in the vertical direction. It has become. The package substrate 30 is made of, for example, low temperature co-fired ceramics. The package substrate 30 has an open container shape with an open top, and has a square back surface 30a (see FIGS. 4A and 4B) and side surfaces 30b and 30c surrounding the square back surface 30a. The side surface 30b is a pair of side surfaces facing the X direction, and the side surface 30c is a pair of side surfaces facing the Y direction (a direction orthogonal to the X direction). The semiconductor chip is not limited to a CMOS image sensor, and may be a chip on which a CCD image sensor is formed.

  A cover glass 31 is fitted into the opened upper portion of the package substrate 30. The cover glass 31 covers the imaging unit so as to protect the imaging unit formed on the semiconductor chip.

  As shown in FIG. 4A, a plurality of first bonding electrodes 32 are arranged in a square lattice pattern at the center of the back surface 30a of the package substrate 30. A plurality of second bonding electrodes 33 are provided on the peripheral edge of the back surface 30 a of the package substrate 30. As shown in FIG. 4B, the surface of each second bonding electrode 33 is exposed from the back surface 30a of the package substrate 30 to the side surfaces 30b and 30c. The first and second bonding electrodes 32 and 33 are external terminals for inputting or outputting signals to the solid-state imaging device 27, are made of metal members, and are embedded in the package substrate 30. The arrangement of the first bonding electrode 32 may not be a square lattice.

  A solder ball 34 is formed on the surface of the first bonding electrode 32 in order to mount the solid-state imaging device 27 on the printed circuit board 28. One second bonding electrode 33 is connected to the printed circuit board 28 by a solder paste described later. The total number of the first and second junction electrodes 32 and 33 is actually about several tens to one hundred and several tens. However, for simplification of the drawing, in FIG. Only 12 two-junction electrodes 33 are shown.

  Returning to FIG. 3, the printed circuit board 28 is a rectangular parallelepiped rigid board that is flattened in the vertical direction, and has a rectangular upper surface 28 a on which the solid-state imaging device 27 is mounted, and side surfaces 28 b and 28 c surrounding the rectangular upper surface 28 a. The side surface 28b is a pair of side surfaces on the long side facing the X direction, and the side surface 28c is a pair of side surfaces on the short side facing the Y direction. The printed circuit board 28 has substantially the same width W as the solid-state image sensor 27 in the X direction, and the side surface 28b is a side surface of the solid-state image sensor 27 in a state where the solid-state image sensor 27 is mounted on the printed circuit board 28. A substantially identical plane is formed together with 30b. The length of the printed circuit board 28 in one Y direction is longer than the width of the solid-state image sensor 27, and the side surface 28 c is located outside the side surface 30 c of the solid-state image sensor 27.

  As shown in FIG. 5A, a plurality of first and second land electrodes 40 and 41 are formed on the upper surface 28 a of the printed circuit board 28. The first land electrode 40 is provided at a position corresponding to the first bonding electrode 32 of the solid-state imaging device 27 and a position corresponding to the second bonding electrode 33 disposed on the side surface 30c. One second land electrode 41 is provided at a position corresponding to the second bonding electrode 33 disposed on the side surface 30 b of the solid-state imaging device 27.

  As shown in FIG. 5B, the second land electrode 41 cuts a columnar electrode in which a conductive member is embedded in a through hole provided so as to penetrate the printed board 28 in the vertical direction in the vertical direction. This is a so-called through-hole structure having a semi-cylindrical shape, and the surface is exposed to the side surface 28b. The conductive member is a metal film such as Cu, and can be embedded in the through hole by a plating method.

  FIG. 6 shows a state where a semiconductor device in which the solid-state imaging device 27 is mounted on the printed board 28 is cut along the X direction. A solder paste 50 is provided on the second land electrode 41 of the printed circuit board 28. For mounting the solid-state imaging device 27 on the printed circuit board 28, the solder ball 34 is brought into contact with the first land electrode 40, and the second bonding electrode 33 is brought into contact with the solder paste 50, and reflow (heating process) is performed. Is made by As a result, the solid-state imaging device 27 is electrically and mechanically joined to the printed circuit board 28.

  As described above, by providing the second bonding electrodes 33 on the side surfaces 30b and 30c of the solid-state image sensor 27, the number of external terminals can be increased without increasing the size of the solid-state image sensor 27. Thereby, the mounting area of the solid-state image sensor 27 can be reduced.

  Further, the printed circuit board 28 is provided with the second land electrode 41 on the side surface 28b, and the width in the X direction, which is the thickness direction of the housing 11, is matched with the width of the solid-state imaging device 27 (that is, the width of the mounting surface). It can be substantially the same. Therefore, the width dimensions of the solid-state imaging device 27 and the printed board 28 in the X direction can be reduced, and the thickness of the housing 11 can be reduced.

  Moreover, since the 2nd joining electrode 33 and the 2nd land electrode 41 can use a side surface as a joining surface of the solder paste 50 in addition to the mutually opposing surface, joining is performed reliably and stably.

  In the above embodiment, the first bonding electrode 32 is bonded to the first land electrode 40 via the solder ball 34. However, the present invention is not limited to this, and other solder paste or the like is used. Bonding with a conductive bonding material is also possible.

  For example, as shown in FIG. 7, a solder paste 60 is formed on the first and second land electrodes 40 and 41 of the printed circuit board 28 by screen printing, and the first and second joining electrodes 32 are formed on each solder paste 60. The solid-state image sensor 27 is bonded to the printed circuit board 28 by performing reflow in a state where the solid-state image sensor 27 is placed so that the contact points are in contact with each other. According to this bonding method, the process of forming solder balls on the solid-state image sensor 27 is not necessary, and the manufacturing process can be simplified.

  In the above embodiment, the package substrate 30 is formed of low-temperature co-fired ceramics. However, the present invention is not limited to this, and the package substrate 30 may be formed of resin.

  In the above-described embodiment, the digital camera 10 incorporating the semiconductor device in which the solid-state image sensor 27 is mounted on the printed board 28 has been described as an example. However, the present invention is not limited to this and the solid-state image sensor is not limited thereto. The present invention can be applied to various electronic devices incorporating a semiconductor device in which a semiconductor package other than elements is mounted on a printed board.

1 is an external perspective view of a digital camera according to the present invention. It is sectional drawing of the bending optical system which follows the AA line of FIG. It is an external appearance perspective view of a solid-state image sensor and a printed circuit board. (A) is a top view which shows the back surface of a solid-state image sensor, (B) is sectional drawing which follows the BB line of the same figure (A). (A) is a top view which shows the upper surface of a printed circuit board, (B) is sectional drawing which follows the CC line | wire of the same figure (A). It is sectional drawing of the semiconductor device which mounts a solid-state image sensor on a printed circuit board. It is sectional drawing for demonstrating the other joining method of a solid-state image sensor and a printed circuit board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Digital camera 11 Housing | casing 15 Bending optical system 27 Solid-state image sensor 28 Printed circuit board 28a Upper surface 28b, 28c Side surface 30 Package substrate 30a Back surface 30b, 30c Side surface 31 Cover glass 32 1st bonding electrode 33 2nd bonding electrode 34 Solder ball (conductivity) Bonding material)
40 First land electrode 41 Second land electrode 50, 60 Solder paste (conductive bonding material)

Claims (6)

A substantially rectangular parallelepiped semiconductor package in which a first bonding electrode is disposed on the back surface, a second bonding electrode is disposed on each of a pair of side surfaces facing in one direction, and a semiconductor chip is sealed inside;
A first land electrode is disposed on the upper surface facing the back surface, a second land electrode is disposed on each of the pair of side surfaces facing the one direction, and the width dimension is substantially the same as the semiconductor package in the one direction. A substrate,
A conductive bonding material for electrically and mechanically bonding between the first bonding electrode and the first land electrode and between the second bonding electrode and the second land electrode;
A semiconductor device comprising:   The semiconductor device according to claim 1, wherein the second land electrode has a cross-sectional through-hole structure.   The semiconductor device according to claim 1, wherein the semiconductor package is made of low-temperature co-fired ceramics.   The semiconductor device according to claim 1, wherein the semiconductor package is made of a resin.   5. The semiconductor device according to claim 1, wherein a solder ball is formed on the first bonding electrode as a conductive bonding material. 6.   The first and second bonding electrodes are bonded to the first and second land electrodes via a conductive bonding material formed by a screen printing method. 2. A semiconductor device according to item 1.

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