Camera module

The present invention relates to a camera module.

In recent years, products equipped with a camera function in small mobile devices such as mobile phones and PDAs have been put on the market. Since these mobile devices are supposed to be carried around, they are required to be miniaturized, and along with this, the camera module mounted inside is also required to be miniaturized.

In a conventional camera module, a bare solid-state image sensor is mounted on a ceramic substrate, a glass epoxy substrate, a flexible substrate, or the like, and a housing is mounted on the substrate so as to cover the mounted solid-state image sensor. It had been. (See, for example, Patent Document 1)

FIG. 3 is a schematic cross-sectional view showing an example of a conventional camera module in which a housing is mounted on a substrate in this way. A solid-state image sensor 2 is mounted on the substrate 1, and is connected to an electrode 1a formed on the substrate 1 by a plurality of wires 3. Further, on the substrate 1, a housing 4 on which the lens barrel 5 is mounted so as to cover the mounted solid-state image sensor 2 and the wire 3 is fixed by an adhesive or the like, and is configured as a camera module.<patcit num="1"><text>Japanese Unexamined Patent Publication No. 2002-51268</text></patcit>

<p> When mounting the housing on the substrate, it is necessary that the optical axis of the lens held in the housing and the surface of the solid-state image sensor are perpendicular to each other. However, the substrate on which the housing is mounted is usually a flexible substrate, a ceramic substrate, or the like, and is easily distorted or bent. Therefore, when the housing is mounted on the substrate, the housing is tilted with respect to the substrate. In some cases, an inclination occurs between the optical axis of the lens and the surface of the solid-state image sensor. As a matter of course, a good image cannot be obtained if the optical axis of the lens and the surface of the solid-state image sensor are tilted.</p><p> Further, in the conventional configuration, since the housing is mounted so as to cover the solid-state image sensor mounted on the substrate, the outer size of the housing becomes large, and the miniaturization of the camera module has been stopped. The miniaturization of the camera module is an important issue to be solved, but as mentioned above, the miniaturization of mobile devices is accelerating, and there is a limit to the miniaturization of such a conventional configuration. The present invention has been made in view of such problems, and an object of the present invention is to provide a compact camera module in which the inclination of the housing (lens) with respect to the solid-state image sensor surface is minimized.</p>

<p> The camera module is composed of at least a substrate on which electrodes are formed, an image sensor mounted on the substrate, and a housing mounted on the image sensor so as to cover the light receiving region of the image sensor. ..</p><p> The image sensor is a camera module connected to an electrode formed on the substrate by a conducting wire.</p><p> The lead wire and the outer peripheral portion of the image sensor shall be a camera module covered with resin.</p><p> The image pickup device is flip-chip mounted on the substrate, and the substrate has an opening at a position facing the light receiving region of the image pickup device, and the housing is mounted on the image pickup device through the opening. The camera module is.</p><p> A camera module is provided with a flange portion that shields the peripheral edge of the opening on the outer peripheral surface of the housing.</p><p> A camera module in which a resin is coated between the outer periphery of the housing and the periphery of the opening.</p><p> The end of the contact surface between the housing and the image sensor is a camera module covered with resin.</p><p> The resin is a camera module having a light-shielding property.</p><p> The housing and the image sensor are joined by a light-shielding adhesive to form a camera module.</p>

<p> In the present invention, since the housing holding the lens is directly mounted on the solid-state image sensor, the optical axis of the lens and the surface of the solid-state image sensor are angularly displaced due to distortion or bending of the substrate as in the conventional case. A good image can be obtained. Further, since the solid-state image sensor and the wire are protected by the resin, the space of the housing portion covering the solid-state image sensor is not required, and the outer size of the housing can be reduced.</p>

A solid-state image sensor is mounted on a substrate, and a housing with a lens is mounted on a portion outside the light-receiving area of the solid-state image sensor. The electrodes of the solid-state image sensor and the electrodes of the substrate are connected by wires, and a resin is applied to protect the entire wire and the exposed portion of the solid-state image sensor.

FIG. 1 is a schematic cross-sectional view showing an embodiment of the present invention. The same members as in the conventional case are designated by the same reference numerals. A solid-state image sensor 2 is fixed on the substrate 1 with an adhesive (not shown), and is electrically conductive with an electrode 1a formed on the substrate 1 by a conductive wire 3. Since the outer peripheral portion of the wire 3 or the solid-state image sensor 2 may be short-circuited or damaged as it is, it is necessary to apply, for example, an epoxy resin 10 or the like to protect it from the outside. The resin 10 only needs to be applied so as to cover at least the outer peripheral portion of the wire 3 and the solid-state image sensor 2, and the outer size does not increase as compared with the case where the resin 10 is covered by using the conventional housing 4. That is, the space for applying the resin 10 is smaller than the space covered by the housing 4. Further, examples of the substrate 1 include those made of a ceramic material, glass epoxy, a flexible substrate, and the like, which can be appropriately selected depending on the intended use.

On the solid-state image sensor 2, a housing 11 in which a lens 11a is incorporated is mounted so as to cover the light receiving area 2a. Generally, the outer periphery of the light receiving area 2a of the solid-state image sensor 2 is a silicon portion covered with an insulating film (not shown), and there is a space on which a lightweight component can be placed. The housing 11 is a lightweight component made of plastic or the like, and is fixed to the space around the light receiving area 2a by an adhesive (not shown). However, during manufacturing, care must be taken so that the adhesive does not protrude into the light receiving area 2a of the solid-state image sensor 2.

Generally, a solid-state image sensor is formed of silicon (Si), its surface is flat, and its distortion and bending due to stress are less than those of a flexible substrate and a ceramic substrate. Therefore, if the housing is mounted directly on the solid-state image sensor, the optical axis of the lens and the surface of the solid-state image sensor are inevitably accurately positioned at an angle.

Further, by using a light-shielding resin 10 to be applied to the wire 3 and covering the end of the joint surface between the housing 11 and the solid-state image sensor 2, from the gap between the housing 11 and the solid-state image sensor 2. It is possible to prevent dust and light from entering the inside of the housing 11, and it is possible to increase the adhesive strength of the housing 11 to the solid-state image sensor 2. The resin applied to the end of the adhesive surface between the housing 11 and the solid-state image sensor 2 may be applied separately from the resin 10 applied to the wire 3, but considering workability, it may be applied to the wire 3. It is better to cover it with the resin 10 to be applied at once. In terms of preventing the intrusion of light, it is desirable to use a light-shielding adhesive for adhering the housing 11 onto the solid-state image sensor 2.

FIG. 2 is a schematic cross-sectional view showing another embodiment of the present invention. In the above-described first embodiment, a mode in which the solid-state image sensor is mounted on the substrate to establish conduction with the substrate by a wire has been described, but in the second embodiment, the solid-state image sensor is mounted on the back surface side of the substrate by a flip chip. Will be described.

A solid-state image sensor 2 is flip-chip mounted on the back surface side of the substrate 20, and an electrode (not shown) formed on the surface of the solid-state image sensor 2 on the light receiving area 2a side and an electrode formed on the back surface of the substrate (not shown). ) Is connected via a conductive adhesive 21 or the like. An opening 20a is provided at a position of the substrate 20 facing the light receiving area 2a of the solid-state image sensor 2, and the light receiving area 2a of the solid-state image sensor 2 is exposed through the opening 20a. The opening 20a is formed wider than the light receiving area 2a according to the external dimensions of the housing 22, and the housing 22 is mounted on the solid-state image sensor 2 through that portion.

Further, the peripheral edge of the opening 20a is coated with a light-shielding resin 23 or the like to fill the gap between the opening 20a and the housing 20 to prevent dust and light from entering the solid-state image sensor 2. , The adhesive strength between the housing 22 and the substrate 20 is increased. In particular, in this embodiment, a flange portion 22a that shields the peripheral edge of the opening 20a is provided on the outer peripheral surface of the housing 22, thereby shielding the gap between the housing 22 and the opening 20a from the outside and resin. The sticking force of 23 is further enhanced.

By mounting the solid-state image sensor on the substrate by the flip-chip method in this way, the wire as in the first embodiment becomes unnecessary, and the housing is mounted through the opening so that the solid-state image sensor is mounted on the substrate surface. Since the protrusion of the housing in the height direction is reduced as compared with the case of mounting the above, further miniaturization is possible.

As described above, the gist of the present invention is to mount the housing directly on the solid-state image sensor to minimize the inclination of the housing when mounted on the substrate and to reduce the size of the configuration. The technical scope thereof is not limited to the embodiments described in the present specification, and other configurations may be used as long as the gist of the present invention is not deviated.

<figref num="1">Schematic cross-sectional view showing the camera module of the present invention (Example 1)</figref><figref num="2">Schematic cross-sectional view showing the camera module of the present invention (Example 2)</figref><figref num="3">Schematic cross-sectional view showing a conventional camera module</figref>

Code description

1 Substrate 1a Electrode 2 Solid-state image sensor 2a Light receiving area 3 Wire 4 Housing 5 Lens barrel 10 Resin 11 Housing 11a Lens 20 Board 20a Opening 21 Conductive adhesive 22 Housing 22a Border 23 Resin