Solid-state image pickup apparatus, method of manufacturing the same, and electronic device including the same

In a solid-state image pickup apparatus 100 of the invention, a transparent member 4 that covers a light receiving section of a solid-state image sensing device 2 is located within an opening 10 of a wiring board 1. The solid-state image sensing device 2 is adhered to the backside of the wiring board 1 via a conductive member 5 and also sealed to the backside of the wiring board 1 with an encapsulation resin 6 formed around the solid-state image sensing device 2. Furthermore, a through-hole 11 passing through the wiring board 1 in a thickness direction is formed on outside of the opening 10 of the wiring board 1, and the through-hole 11 is filled with the encapsulation resin 6. This configuration provides the solid-state image pickup apparatus 100 in which the encapsulation resin 6 can be easily injected to the surrounding area of the solid-state image sensing device 2.

This Nonprovisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 312764/2007 filed in Japan on Dec. 3, 2007, the entire contents of which are hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to a solid-state image pickup apparatus, a method for manufacturing the solid-state image pickup apparatus, and an electronic device including the solid-state image pickup apparatus.

BACKGROUND OF THE INVENTION

On a solid-state image pickup apparatus for imaging, a solid-state image sensing device (CCD (charge-coupled device) or CMOS (complementary metal-oxide semiconductor) sensor IC (integrated circuits)) is mounted. The solid-state image pickup apparatus is used for mobile terminals such as communication equipments, including a mobile phone. Recently, mobile terminals have been increasingly becoming smaller and thinner, which resulted in a higher need for the solid-state image pickup apparatus to be thinner and smaller.

Depending on the need, a solid-state image pickup apparatus made aiming for being thinner and smaller has been disclosed in patent document 1.FIG. 8shows a cross-sectional view of the solid-state image pickup apparatus in the patent document 1.FIG. 9shows a schematic view of a front side of the solid-state image pickup apparatus in the patent document 1.

As shown inFIGS. 8 and 9, in a solid-state image pickup apparatus200of the patent document 1, a transparent member204is placed above a solid-state image sensing device202in such a manner that the transparent member204covers a light receiving section221of the solid-state image sensing device202. Furthermore, an electrode pad209of the solid-state image sensing device202and a wiring board201are connected with each other via a conductive member205. In the solid-state image pickup apparatus200as such, the transparent member204is inserted in an opening210of the wiring board201, and a top surface of the transparent member204is located within the opening210.

However, in the solid-state image pickup apparatus of the patent document 1, there is a problem in which it is difficult to inject an encapsulation resin into a surrounding area of the solid-state image sensing device.

Specifically, in the solid-state image pickup apparatus of the patent document 1, no through-hole, via which the encapsulation resin is injected, is formed on the wiring board. Therefore, when the encapsulation resin is to be formed around the solid-state image sensing device in the patent document 1, the encapsulation resin is required to be injected to the solid-state image sensing device sideways. However, it is very difficult to inject the encapsulation resin to such an extremely small member as the solid-state image sensing device sideways. That is, in the configuration of the patent document 1, once the solid-state image sensing device is connected to the wiring board via the electrode and the conductive member, it is difficult to reinforce the connection afterwards.

As shown inFIG. 8, in the configuration of the solid-state image pickup apparatus200, the electrode pad209of the solid-state image sensing device202and the wiring board201are connected with each other only via the conductive member205. This means the connection between the solid-state image sensing device202and the wiring board201is not so strong, which leads to a state in which the solid-state image sensing device202is easily fallen off from the wiring board201.

Patent Document 1

SUMMARY OF THE INVENTION

The invention is made to solve the above problem, and an object of the invention is to provide a solid-state image pickup apparatus, in which it is possible to easily inject the encapsulation resin to a surrounding area of the solid-state image sensing device. Moreover, a further object of the invention is to provide a solid-state image pickup apparatus, in which the connection between the solid-state image sensing device and a wiring board is strong.

In order to achieve the objects above, a solid-state image pickup apparatus according to the present invention comprises:a solid-state image sensing device;a wiring board including wiring to be electrically connected to the solid-state image sensing device, and having an opening passing through the wiring board in a thickness direction; anda transparent member provided above the solid-state image sensing device in such a manner that the transparent member covers a light receiving section of the solid-state image sensing device with a space between the transparent member and the light receiving section,

at least a part of the transparent member being located within the opening of the wiring board; and

the solid-state image sensing device having a light receiving surface adhered to a backside of the wiring board,

wherein the solid-state image sensing device is sealed to the wiring board with an encapsulation resin formed around the solid-state image sensing device; and a through-hole passing through the wiring board in a thickness direction is formed on outside of the opening of the wiring board.

In the above configuration, the encapsulation resin is formed around the solid-state image sensing device that is adhered to the backside of the wiring board, and the encapsulation resin seals the solid-state image sensing device to the wiring board. In other words, in the above configuration, the solid-state image sensing device is adhered to the backside of the wiring board, as well as fixed to the backside of the wiring board with the encapsulation resin formed around the solid-state image sensing device. In this manner, the solid-state image sensing device is firmly fixed to the backside of the wiring board, which makes it possible to reinforce the connection between the solid-state image sensing device and the wiring board, as well as increase the strength of the solid-state image pickup apparatus.

In addition, in the above configuration, the through-hole of the wiring board is formed on outside of the opening, within which the transparent member is located. This makes it possible to easily provide the encapsulation resin around the solid-state image sensing device, by injecting the encapsulation resin through the through-hole. This configuration can improve productivity of the solid-state image pickup apparatus, as a result of which the high-quality solid-state image pickup apparatus, in which the connection between the solid-state image sensing device and the wiring board is strong, can be manufactured at low cost.

A method according to the present invention is a method of producing a solid-state image pickup apparatus,

the solid-state image pickup apparatus comprising: a solid-state image sensing device;a wiring board including wiring to be electrically connected to the solid-state image sensing device, and having an opening passing through the wiring board in a thickness direction; anda transparent member provided above the solid-state image sensing device in such a manner that the transparent member covers a light receiving section of the solid-state image sensing device with a space between the transparent member and the light receiving section,at least a part of the transparent member being located within the opening of the wiring board, andthe solid-state image sensing device having a light receiving surface adhered to a backside of the wiring board. In order to achieve the objects above, the method according to the present invention comprises the steps of:forming the through-hole passing through the wiring board in the thickness direction on outside of the opening formed on the wiring board; andsealing the solid-state image sensing device to the wiring board with an encapsulation resin formed around the solid-state image sensing device, by injecting the encapsulation resin via the through-hole.

With the above method, the encapsulation resin is formed around the solid-state image sensing device that is adhered to the backside of the wiring board, and the encapsulation resin seals the solid-state image sensing device to the wiring board. In other words, with the above method, the solid-state image sensing device is adhered to the backside of the wiring board, as well as fixed to the backside of the wiring board with the encapsulation resin formed around the solid-state image sensing device. In this manner, the solid-state image sensing device is firmly fixed to the backside of the wiring board, which makes it possible to reinforce the connection between the solid-state image sensing device and the wiring board, as well as increase the strength of the solid-state image pickup apparatus.

In addition, with the above method, the through-hole of the wiring board is formed on outside of the opening, within which the transparent member is located. This makes it possible to easily provide the encapsulation resin around the solid-state image sensing device, by injecting the encapsulation resin through the through-hole. This configuration can improve productivity of the solid-state image pickup apparatus, as a result of which the high-quality solid-state image pickup apparatus, in which the connection between the solid-state image sensing device and the wiring board is strong, can be manufactured at low cost.

Additional objects, features, and strengths of the invention will be made clear by the description below. Further, the advantages of the invention will be evident from the following explanation in reference to the drawings.

DESCRIPTION OF THE EMBODIMENTS

One embodiment of the present invention is described below with reference to the drawings.FIG. 1shows a cross-sectional view of a schematic configuration of a solid-state image pickup apparatus of the invention.

As shown inFIG. 1, a solid-state image pickup apparatus100mainly includes a wiring board1, a solid-state image sensing device2, a lens unit3, and a transparent member4. The wiring board1has an opening10. The solid-state image sensing device2is adhered to a backside of the wiring board1. The lens unit3is used to direct light coming from outside to the solid-state image sensing device2. The transparent member4is placed above and facing the solid-state image sensing device2. In the solid-state image pickup apparatus100, the wiring board1and solid-state image sensing device2are electrically connected with each other via a conductive member5.

The wiring board1is a board for taking out an electric signal of the solid-state image sensing device2, and includes patterned wiring (not illustrated). The wiring board1is, for example, a printed board or a ceramic board. On the wiring board1, the opening10passing through the wiring board1in a thickness direction is formed. The transparent member4is located within the opening10, and the solid-state image sensing device2is fixed to the backside of the wiring board1. Therefore, the opening10is larger in size than the transparent member4and smaller in size than the solid-state image sensing device2. In addition, an electrode for external connection (not illustrated) is formed on the backside of the wiring board1. Also, as described later, on the wiring board1, through-holes passing through the wiring board1in the thickness direction are formed on outside of the opening10.

The solid-state image sensing device2that is adhered to the backside of the wiring board1is a flat, rectangular-shaped semiconductor substrate, on which a semiconductor circuit is formed (such as a silicon monocrystalline substrate). The solid-state image sensing device2is, for example, a CCD (charge-coupled device) image sensor, CMOS (complementary metal-oxide semiconductor) image sensor, or VMIS image sensor (Threshold Voltage Modulation Image Sensor). On the solid-state image sensing device2, a light receiving section (image pickup section)21is formed. In the light receiving section21, light receiving elements (picture elements) are provided in matrix. The light receiving section21has a rectangular-shape two-dimensionally. The light receiving section21is placed in a center of the front side (surface) of the solid-state image sensing device2. By the light receiving elements, a subject image formed on the light receiving section21(light came through the transparent member4) is converted to an electric signal.

On the surrounding area (on the outer edge) of the solid-state image sensing device2, an encapsulation resin6is provided. The encapsulation resin6seals the solid-state image sensing device2to the backside of the wiring board1. And as described later, in the embodiment, the encapsulation resin6also fills up the through-holes of the wiring board1.

The lens unit3directs light coming from outside to the solid-state image sensing device2. The lens unit3includes a lens31and a lens holder (a tube, a light path-fixing device)32that holds the lens31therein. The lens unit3is adhered to the front side of the wiring board1(the opposite side of the solid-state image sensing device2) via a resin layer7.

The lens holder32is a hollow tube, inside of which the transparent member4is placed above and facing the solid-state image sensing device2.

The transparent member4is placed in such a manner that the transparent member4covers the light receiving section21of the solid-state image sensing device2. The transparent member4is adhered to the solid-state image sensing device2via an adhering section8that is formed around the solid-state image sensing device2. That is, there will be an enclosed space (gap) formed between the transparent member4and the solid-state image sensing device2. In this manner, the transparent member4is placed above the solid-state image sensing device2, without contacting the solid-state image sensing device2(light receiving section21). In addition, the side surface (edge surface) of the transparent member4and the encapsulation resin6function as a dam, which can prevent foreign particles (a cause of yield loss) from entering into the light receiving section21. This makes it possible to protect the light receiving section2against foreign particles even when the solid-state image sensing device2is mounted on the wiring board1, on which foreign particles are easily attached. As a result, yield loss can be kept at a minimum.

The transparent member4is formed from a material with transparency, such as glass or resin. At least a part of the transparent member4(at least a part that is covering the light receiving section21) needs to be located inside the opening10of the wiring board1. On the surface of the transparent member4(the surface facing to the lens unit3), an optical filter (e.g., infrared cut filer) may be formed.

FIG. 2shows a cross-sectional view of the configuration of the solid-state image pickup apparatus100ofFIG. 1, except for the lens unit3.FIG. 3shows a top view of the solid-state image pickup apparatus100ofFIG. 2. The encapsulation resin6is not illustrated inFIG. 3.

As shown inFIG. 2, on the light-receiving surface of the solid-state image sensing device2, an electrode pad9is formed outside the light receiving section21. The conductive member5that is formed on top of the electrode pad9adheres the solid-state image sensing device2to the backside of the wiring board1. In this manner, the wiring board1and the solid-state image sensing device2are electrically connected with each other.

Further, in the solid-state image pickup apparatus100of the embodiment, through-holes11passing through the wiring board1in a thickness direction are formed on outside of the opening10. In the embodiment, two through-holes11are formed along the side surface (outer edge) of the solid-state image sensing device2, which is indicated with a dashed line ofFIG. 3. The two through-holes11are formed on the two different sides of the solid-state image sensing device2, the two sides being opposed to each other. And the encapsulation resin (not illustrated inFIG. 3) fills up the through-holes11. In the embodiment, there is no resin layer7formed on extension lines of the through-holes11, and so the encapsulation resin6also fills up these parts.

The solid-state image pickup apparatus100takes light from outside, through the lens unit3. Then the light goes through the transparent member4toward the light receiving section21of the solid-state image sensing device2. In the light receiving section21, the light receiving elements receive a picture image. Because there is nothing placed between the light receiving section21and the transparent member4, the light came from outside and went through the transparent member4is to directly reach the light receiving section21, and so there will be no light loss on the light path.

In the above configuration of the solid-state image pickup apparatus100, the solid-state image sensing device2is sealed to the wiring board1with the encapsulation resin6that is formed around the solid-state image sensing device2. That is, the solid-state image sensing device2is adhered to the backside of the wiring board1via the conductive member5, as well as fixed to the backside of the wiring board1with the encapsulation resin6that is formed on the outer edge of the solid-state image sensing device2. In this manner, the solid-state image sensing device2is firmly fixed to the backside of the wiring board1. This makes it possible to reinforce the connection between the solid-state image sensing device2and the wiring board1, as well as increase the strength of the solid-state image pickup apparatus100itself. The encapsulation resin6needs to be formed at least on the surrounding area of the solid-state image sensing device2so as to fix the solid-state image sensing device2to the backside of the wiring board1.

In addition, in the solid-state image pickup apparatus100of the invention, the through-holes11are formed on outside of the opening10of the wiring board1. Therefore, as described later, it is possible to easily provide the encapsulation resin6around the solid-state image sensing device2, by injecting the encapsulation resin6through the through-holes11.

The through-hole11may be formed anywhere as long as it is on outside of the opening10of the wiring board1. But it is preferable that it be formed on the extension line of the side surface of the solid-state image sensing device2, so that the encapsulation resin6can be injected through the through-hole11and definitely provided around the solid-state image sensing device2by capillary action. In this way, the sealing part of the encapsulation resin6can be definitely formed around the solid-state image sensing device2. One through-hole11is enough for providing the encapsulation resin6around the solid-state image sensing device2.

Further, in the solid-state image pickup apparatus100, outlets of the through-holes11formed on the backside of the wiring board1are sealed with the encapsulation resin6. This can prevent foreign particles from entering into the solid-state image sensing device2, through the through-holes11.

Furthermore, in the solid-state image pickup apparatus100, the through-holes11are filled with the encapsulation resin6. This can increase the strength of the wiring board1, which has been weakened due to the formed through-holes11. This also can increase the strength of the solid-state image pickup apparatus100itself.

The encapsulation resin6can be made either of heat-curing resin or light (e.g., ultraviolet light)-curing resin. For reinforcing the connection between the solid-state image sensing device2and the wiring board1, the encapsulation resin6may be made either of transparent resin or light shielding resin. However, if the encapsulation resin6is made of light shielding resin such as colored resin, the encapsulation resin6will have a light blocking effect. As a result, light entering into the light receiving section21of the solid-state image sensing device2through the encapsulation resin6can be prevented.

Moreover, in the solid-state image pickup apparatus100, the resin layer7is formed on the front side (the opposite side of the solid-state image sensing device2) of the wiring board1. The resin layer7functions as a reinforcing material for increasing the strength of the wiring board1, so that the solid-state image sensing device2can be firmly mounted on the wiring board1.

Like the encapsulation resin6, the resin layer7can also be made either of heat-curing resin or light (e.g., ultraviolet light)-curing resin. For increasing the strength of the wiring board1, the resin layer7may be made either of transparent resin or light shielding resin. However, if the resin layer7is made of light shielding resin such as colored resin, the resin layer7will have a light blocking effect. As a result, light entering into the light receiving section21of the solid-state image sensing device2through the resin layer7can be prevented. It is preferable that the resin layer7be adhesive resin that functions as an adhesive, so as to adhere the lens unit3to the wiring board1.

As described above, a main object of the encapsulation resin6and the resin layer7is to increase the strength of the wiring board1(to reinforce the connection between the solid-state image sensing device2and the wiring board1). Therefore, the resin need not have a light blocking effect. However, if the resin of the encapsulation resin6and the resin layer7were to have a light blocking effect, the resin not only function as a reinforcing material, but also block the light from entering into the light receiving section21.

Next, one embodiment of a method for manufacturing the solid-state image pickup apparatus100is described below with reference toFIG. 4.FIG. 4is a cross-sectional view showing steps of a method for manufacturing the solid-state image pickup apparatus100. The method for manufacturing the solid-state image pickup apparatus100includes a step, in which the encapsulation resin is injected to the surrounding area of the solid-state image sensing device and then the solid-state image sensing device is sealed to the wiring board with the encapsulation resin.

First, as shown inFIG. 4, the transparent member4is mounted on each solid-state image sensing device2of an wafer20. The wafer20includes a plurality of solid-state image sensing devices2. Then, by dicing the wafer20at a dashed line, single-cut solid-state image sensing devices2are prepared.

Next, the solid-state image sensing device2is mounted on the backside of the wiring board1via the conductive member5. At this point, the transparent member4that is mounted on the solid-state image sensing device2is located within the opening10of the wiring board1. In this step, the through-holes11of the wiring board1and the resin layer7should be formed in advance, but the resin layer7should not cover the through-holes11.

Then, the through-holes11are filled with the encapsulation resin6injected by a resin filler60through the through-holes11of the wiring board1, on which the solid-state image sensing device2is mounted. In this step, the encapsulation resin6is definitely provided around the solid-state image sensing device2by a capillary action, due to high viscosity of the resin. After that, the encapsulation resin6is cured.

Finally, the lens unit3is placed on the wiring board1. By curing the resin layer7, the wiring board1and lens unit3are adhered with each other. In this way, the solid-state image pickup apparatus100can be produced.

As described above, this method of manufacture makes it possible to produce the solid-state image pickup apparatus100, in which the solid-state image sensing device2is firmly fixed to the backside of the wiring board1. This makes it possible to reinforce the connection between the solid-state image sensing device2and the wiring board1.

Moreover, the encapsulation resin6can be easily provided around the solid-state image sensing device2, by injecting the encapsulation resin6through the through-holes11. As a result, productivity of the solid-state image pickup apparatus100can be improved, as a result of which high-quality solid-state image pickup apparatus100, in which the connection between the solid-state image sensing device2and the wiring board1is strong, can be manufactured at low cost.

Moreover, the solid-state image pickup apparatus100may be configured as follows.FIGS. 5 to 7are cross-sectional views of other solid-state image pickup apparatuses of the invention.

On a solid-state image pickup apparatus101ofFIG. 5, neither encapsulation resin6nor resin layer7is formed inside through-holes11. This configuration can also reinforce the connection between a solid-state image sensing device2and a wiring board1due to the encapsulation resin6.

In a solid-state image pickup apparatus102ofFIG. 6, through-holes11are filled with resin of resin layer7, instead of the encapsulation resin6. This configuration can also provide the same advantage as the configuration where the through-holes11are filled with the encapsulation resin6(the solid-state image pickup apparatus100). In this case, unlike the method inFIG. 4, if the resin layer7was formed after the solid-state image sensing device2is mounted on the wiring board1, the formation of the resin layer7and the filling the through-holes11with the resin of the resin layer7could be performed in one process concurrently.

In a solid-state image pickup apparatus103ofFIG. 7, the through-holes11are filled with the encapsulation resin6, and the resin layer7is formed on top of that. This configuration can also provide the same advantage as the configuration where the through-holes11are filled with the encapsulation resin6(the solid-state image pickup apparatus100).

The solid-state image pickup apparatus of the invention is suitably applicable to electronic devices that can take pictures, such as a mobile phone having a camera, digital steel camera, video camera, and security camera.

In the embodiments, each of the opening10and through-holes11on the wiring board1are formed separately. However, even if the through-holes11and the opening10are connected, the same advantage as the embodiment can be achieved.

As described above, a solid-state image pickup apparatus of the present invention has a configuration, in which the solid-state image sensing device is sealed to the wiring board with the encapsulation resin formed around the solid-state image sensing device. And, the method for manufacturing the solid-state image pickup apparatus of the present invention has steps of forming the through-hole passing through the wiring board in the thickness direction on the outside of the opening formed on the wiring board, and sealing the solid-state image sensing device to the wiring board with the encapsulation resin formed around the solid-state image sensing device, by injecting the encapsulation resin via the through-hole.

Therefore, it is possible to reinforce the connection between the solid-state image sensing device and the wiring board, and as a result, also possible to increase the strength of the solid-state image pickup apparatus. In addition, the encapsulation resin can be easily provided to the surrounding area of the solid-state image sensing device. This configuration can improve productivity of the solid-state image pickup apparatus, as a result of which the high-quality solid-state image pickup apparatus, in which the connection between the solid-state image sensing device and the wiring board is strong, can be manufactured at low cost.

In the solid-state image pickup apparatus of the present invention, it is preferable that the through-hole be formed on the extension line of the side surface of the solid-state image sensing device.

In the above configuration, the through-hole is formed on the extension line of the side surface of the solid-state image sensing device. This makes it possible for the encapsulation resin to be injected through the through-hole, and the injected encapsulation resin is definitely provided around the solid-state image sensing device by capillary action. That is, the encapsulation resin can be definitely provided to the surrounding area of the solid-state image sensing device.

In the solid-state image pickup apparatus of the present invention, it is preferable that the encapsulation resin seal an outlet of the through-hole formed on the backside of the wiring board.

In the above configuration, the outlet of the through-hole formed on the backside of the wiring board is sealed with the encapsulation resin. This can prevent foreign particles from entering through the through-hole into the solid-state image sensing device.

In the solid-state image pickup apparatus of the present invention, it is preferable that the through-hole be filled with the encapsulation resin.

In the above configuration, the through-hole is filled with the encapsulation resin. This can increase the strength of the wiring board that has been weakened due to the formed through-hole. This means that it is also possible to increase the strength of the solid-state image pickup apparatus itself.

In the solid-state image pickup apparatus of the present invention, it is preferable that a resin layer be formed on the front side of the wiring board.

In the configuration of the patent document 1, no resin layer is formed on the wiring board. Therefore, because of the wiring forms, pressure imposed on the wiring board when the solid-state image sensing device is mounted is dispersed. This results in a state in which the connection between the solid-state image sensing device and the wiring board is not stable.

As against the configuration of the patent document 1, in the above configuration, the resin layer is formed on the front side (opposite side of the solid-state image sensing device) of the wiring board. In this configuration, the resin layer functions as a reinforcing material for increasing the strength of the wiring board. This makes it possible to firmly mount the solid-state image sensing device on the wiring board.

In the solid-state image pickup apparatus of the present invention, it is preferable that the resin layer be made of a material with a light blocking effect.

The above configuration means that the resin layer has a light blocking effect. As a result, light entering into the light receiving section of the solid-state image sensing device through the resin layer can be prevented.

In the solid-state image pickup apparatus of the present invention, it is preferable that the encapsulation resin be made of a material with a light blocking effect.

The above configuration means that the encapsulation resin has a light blocking effect. As a result, light entering into the light receiving section of the solid-state image sensing device through the encapsulation resin can be prevented.

The invention can be preferably employed for a solid-state image pickup apparatus that is to be mounted on mobile terminals such as communication devices, which have been required to be smaller and thinner. In addition, the invention can provide a high-quality solid-state image pickup apparatus at low cost.

The invention is not limited to the description of the embodiments above, but may be altered within the scope of the claims. An embodiment based on a proper combination of technical means disclosed in different embodiments is encompassed in the technical scope of the invention.