Camera module

A camera module of the present invention, provided by adhering a glass substrate to the cover body so that the glass substrate covers an opening of a sensor cover for covering an image pickup element mounted on a wiring substrate, which opening is provided above the image pickup element, the camera module includes: an image pickup package having an internal space provided by the glass substrate, the sensor cover, and the glass substrate; and an image pickup lens provided above the glass substrate of the image pickup package, wherein at least one ventilation groove (G) for allowing the internal space to communicate with open air is provided on an adhesive surface of the glass substrate of the sensor cover.

This application is the U.S. national phase of International Application No. PCT/JP2013/052551, filed 5 Feb. 2013, which designated the U.S. and claims priority to JP Application No. 2012-033039, filed 17 Feb. 2012, and JP Application No. 2013-2897, filed 10 Jan. 2013, the entire contents of each of which are hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a camera module for capturing an image in a camera-equipped mobile phone, a digital camera, a security camera, or the like, and, specifically, relates to ventilation of an internal space of an image pickup package including an image pickup element, a wiring substrate, a lens, and a glass substrate.

BACKGROUND ART

A camera module for use in a camera-equipped mobile phone, a digital camera, a security camera, or the like is structured such that a solid state image pickup element such as CCD (Charge Coupled Device) and CMOS (Complementary Metal Oxide Semiconductor), a wiring substrate including a glass substrate and a terminal, a sensor cover retaining the solid state image pickup element and the wiring substrate, a lens, and a lens holder are integrated.

An example structure of such a camera module is illustrated inFIG. 13. As shown inFIG. 13, a camera module100includes: a lens unit120consisting of a lens121and a lens holder122; and an image pickup package110in which a solid state image pickup element113is placed in an internal space118surrounded by a glass substrate117, a sensor cover114, and a wiring substrate111.

In a case of the camera module100having the above structure, ideally, any foreign matters do not enter the internal space118of the image pickup package110because, when foreign matters are attached onto the solid state image pickup element113, a captured image is deteriorated. However, in a case where the internal space118is airtight completely in order to prevent entry of foreign matters, gas in the internal space118thermally expands due to a rise in temperature, which results in a risk of breakage from a joint section. Further, gas and ions are generated from adhesives112and116etc. due to change in temperature or in atmospheric pressure, which steams up the glass substrate117.

In order to solve the above problem, for example, in a solid state image pickup element200disclosed in Patent Literature 1, as shown inFIG. 14, an adhesive layer219is provided on an inside wall of an image pickup package210, thereby preventing foreign matters from attaching onto a solid state image pickup element213. Further, a through hole211aconnecting inside of the image pickup package210with an outside thereof is provided in a wiring substrate211placed directly under the solid state image pickup element213, so that open air is circulated and gas and ions generated from the adhesive layer219due to change in temperature or in atmospheric pressure are released.

For example, as shown in (a) ofFIG. 15, (b) ofFIG. 15, and (c) ofFIG. 15, Patent Literature 2 proposes an image sensor unit300having such a structure that a ventilation section for allowing an inside of the image pickup package310to communicate with an outside thereof is provided on a flat surface of a sensor cover314. In the image sensor unit300, when the sensor cover314and a glass substrate317are adhered to each other, a ventilation section V for allowing an internal space318to communicate with the outside is provided by providing a region to which an adhesive316is not applied. Further, because an opening section of the ventilation section V inside the image pickup package310is provided outside a region facing a light-receiving surface of an image pickup element313, foreign matters entering the internal space318of the image pickup package310through the ventilation section V are difficult to fall and be attached onto the light-receiving surface.

CITATION LIST

Patent Literature 1

Patent Literature 2

SUMMARY OF INVENTION

Technical Problem

However, the solid state image pickup element200serving as a camera module, disclosed in the above conventional Patent Literature 1, has problems below.

That is, the through hole211a, which is provided to release gas and ions generated from the adhesive layer219due to change in temperature or in atmospheric pressure and allows an inside of the image pickup package210to communicate with an outside thereof, is provided through the wiring substrate211which is bottom of the camera module. Further, the through hole211ais provided directly under the solid state image pickup element213, the solid state image pickup element213and the wiring substrate211are partially adhered, and a thickness of each adhesive layer212is optimized. This makes it possible to release the gas and ions generated from the inside of the image pickup package210and also to prevent entry of foreign matters because foreign matters from outside are larger than the thickness of the adhesive layers212.

However, since the adhesive layers212are partially applied, it is necessary to manage an inclination of the solid state image pickup element213merely with use of the adhesive layers212partially applied. Therefore, in a case where an application amount of the adhesive is different among applied parts, there is a possibility that the thickness of the layers is different and the inclined solid state image pickup element213is mounted on the wiring substrate211.

Further, a case of partially adhering the solid state image pickup element213and the wiring substrate211to form a gap may lead to a weaker adhesive strength, as compared with a case of entirely adhering the interface solid state image pickup element213and the wiring substrate211without any gap. In order to keep the adhesive strength, it is necessary to increase an application amount of the adhesive. In a case where the application amount of the adhesive is increased, there is a possibility that, when the solid state image pickup element213is pressed to the adhesive layers212, areas of the adhesive layers212partially applied are expanded and are then brought into contact with each other, which results in clogging the through hole211a, i.e., the through hole211adoes not function.

Patent Literature 2 discloses that, as a ventilation section V, a region to which the adhesive316is not applied is provided at an adhering section of the sensor cover314and the glass substrate317. However, this configuration has a similar problem to that of Patent Literature 1, specifically, when the glass substrate317is adhered to the sensor cover314, the adhesive316is pressed, and an application area of the adhesive316and is wetted and expanded, and then the adhesive316intrudes into an area to which the adhesive316is not to be applied, which results in clogging the ventilation section. When the region to which the adhesive316is not to be applied is increased to prevent clogging of the ventilation section V with the adhesive316, the potential of intrusion of foreign matters into the inside of the image pickup package310becomes higher. Therefore, in order to have an appropriate ventilation section V having both air-permeability and capability of preventing intrusion of foreign matters, it is necessary to manage the application amount, an application range, and a pressing amount of the adhesive316, which is never easy.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a camera module which can obtain air-permeability between an internal space and an open air of an image pickup package while an image pickup element is not being inclined.

Solution to Problem

In order to achieve the above object, a camera module of an aspect of the present invention includes a substrate, an image pickup element on the substrate, and a cover body for covering the image pickup element on the substrate, a transparent plate being attached to the cover body in such a manner that the transparent plate covers an opening of the cover body which opening is above the image pickup element, so that the substrate, the cover body, and the transparent plate define an internal space; and an image pickup lens provided above the transparent plate of the image pickup package, wherein at least one ventilation groove for allowing the internal space to communicate with open air is provided on a plane of the cover body on which plane the transparent plate is attached.

Advantageous Effects of Invention

In the camera module of an aspect of the present invention, as described above, the at least one ventilation groove for allowing the internal space to communicate with open air is provided on the adhesive surface of the transparent plate of the cover body.

Therefore, it is possible to provide a camera module which can obtain air-permeability between an internal space and an open air of an image pickup package while an image pickup element is not being inclined.

DESCRIPTION OF EMBODIMENTS

The following description will discuss an embodiment of the present invention with reference toFIGS. 1 to 9.

(Basic Configuration of Camera Module)

The following description will discuss a configuration of a camera module according to Embodiment 1 with reference toFIG. 1.FIG. 1is a cross-sectional view illustrating the configuration of the camera module according to Embodiment 1.

As illustrated inFIG. 1, a camera module1of Embodiment 1 includes: an image pickup package10; and a lens unit20serving as an optical section mounted on the image pickup package10.

The image pickup package10includes: a solid state image pickup element13mounted on a wiring substrate11as a substrate via an adhesive12; and a sensor cover14for covering the wiring substrate11and the solid state image pickup element13. The solid state image pickup element13is connected to the wiring substrate11via a wire15.

An opening14ais provided in a center position of the sensor cover14, and, a glass substrate17serving as a transparent plate whose end section is adhered with use of an adhesive16is provided on the opening14a. As a result, an internal space18surrounded by the glass substrate17, the sensor cover14, and the wiring substrate11is provided in the image pickup package10. Note that the transparent plate is not necessarily made of glass, and another transparent plate may be used.

Meanwhile, the lens unit20is made up of an image pickup lens21and a lens holder22for retaining the image pickup lens21. The lens unit20is provided above the solid state image pickup element13and the glass substrate17of the image pickup package10.

Note that, in Embodiment 1, the lens unit20is the simplest fixed-focus lens unit including the image pickup lens21and the lens holder22. However, the lens unit20is not limited thereto, and, even if the lens unit20further includes a lens driving device such as an autofocus mechanism, a zooming mechanism, or a macro photography mechanism, effects of the present invention do not change.

(Ventilation Groove of Camera Module)

In a case of the camera module1of Embodiment 1, thermal expansion of gas in the internal space18may occur due to a rise in temperature, with the result that the adhesive16may come off. Therefore, it is necessary to provide a ventilation hole for allowing the internal space18of the image pickup package10to communicate with the outside. In this case, in a case where the ventilation hole is provided to be placed directly under the image pickup element and the image pickup element and the wiring substrate are partially adhered to each other like the camera module disclosed in Patent Literature 1, the image pickup element may be inclined due to the thickness of the adhesive layers.

In view of the circumstances, the camera module1of Embodiment 1 obtains air-permeability between the internal space18and open air as follows.

A structure for obtaining the air-permeability in Embodiment 1 will be described with reference toFIG. 1, (a) ofFIG. 2, (b) ofFIG. 2, (a) ofFIG. 3, and (b) ofFIG. 3. (a) ofFIG. 2is a plan view illustrating a configuration of the image pickup package10of the camera module1other than the glass substrate17, and (b) ofFIG. 2is a cross-sectional view taken along the arrows X-X of (a) ofFIG. 2. (a) ofFIG. 3is a plan view illustrating a configuration of the image pickup package of the camera module, i.e., a configuration in which the substrate17is mounted, and (b) ofFIG. 3is a cross-sectional view taken along the arrows X-X of (a). (a) ofFIG. 4to (d) ofFIG. 4are plan views illustrating shapes of a ventilation groove provided in the sensor cover14of the image pickup package10on a plan view.

As illustrated inFIG. 1, (a) ofFIG. 2, and (b) ofFIG. 2, in the camera module1of Embodiment 1, a single ventilation groove G for allowing the internal space18to communicate with an outside of the sensor cover14is provided on an adhesive surface of the glass substrate17above the sensor cover14. Specifically, an inner edge of the sensor cover14, i.e., a section in the vicinity of the opening14aprovided centrally is a step section14b, and, on a top surface of the step section14b, the single ventilation groove G extending from an inner side to an outer side is provided. The step section14bis adhered to the glass substrate17via the adhesive16so as to have a gap19between the glass substrate17and a standing-up wall surface14cof the step section14b. As a result, in a state in which the glass substrate17is mounted on the step section14bof the sensor cover14, the internal space18communicates with the outside of the sensor cover14, i.e., open air through the ventilation groove G and the gap19. The lens unit20including the image pickup lens21is provided on the sensor cover14. The lens unit20including the image pickup lens21is not sealed and communicates with the outside of the camera module1, i.e., open air through a minute gap. Such communication between the internal space18and the outside of the sensor cover14is equivalent to communication between the internal space18and the outside of the camera module1, i.e., open air. Air-permeability of the lens unit20is obtained by a minute gap. Therefore, foreign matters hardly intrude into the ventilation groove G from the outside of the camera module1via the lens unit20.

Note that, while only one ventilation groove G is provided in Embodiment 1, it is not always limited thereto, and two or more ventilation grooves may be used. That is, at least one ventilation groove G needs to be provided.

The ventilation groove G is a groove for releasing, toward the outside, gas and ions generated from the adhesives12and16in the internal space18of the image pickup package10. In a case where the glass substrate17is mounted on the sensor cover14, the ventilation groove G is prevented from clogging by having such a depth that the adhesive16extended by pressing is not fully filled with the ventilation groove G.

That is, the adhesive16is applied in a straight line so as to surround the opening14aas shown in the chain double-dashed line in (a) ofFIG. 2, however, the adhesive16is applied near the ventilation groove G.

As described above, in a case where the adhesive16is applied in a straight line to the top surface of the step section14bso as to surround the opening14aand the glass substrate17is mounted, as shown in (a) ofFIG. 3and (b) ofFIG. 3, an area of the adhesive16applied to the top surface of the step section14bis extended and surplus adhesive16is flown into the ventilation groove G. However, by appropriately managing the depth of the ventilation groove G, the ventilation groove G is not completely clogged with the adhesive16, and air-permeability can be obtained by having a gap16a.

The depth of the ventilation groove G is a minimum value that can achieve both purpose of placing the ventilation groove G, i.e., releasing of gas present in the internal space18and prevention of intrusion of foreign matters from the outside unless clogging of the adhesive16is considered. For example, the minimum value is ideally 0.01 mm to 0.1 mm. However, in order to have an extra depth to prevent clogging of the ventilation groove G with the adhesive16flown to the ventilation groove G, the depth is, for example, about 0.015 mm to 0.040 mm appropriately. At this time, the ventilation groove G preferably has a length of, for example, 0.2 mm to 1.0 mm and a width of, for example, 0.1 mm to 0.5 mm.

The shape of the ventilation groove G on a plan view is not always necessary to be a straight line shape and the ventilation groove G can have, for example, a circular arc shape on the plan view. Further, as shown in (a) ofFIG. 4, (b) ofFIG. 4, and (c) ofFIG. 4, the shape on the plan view can be also curved in a square shape or a round shape. As shown in (d) ofFIG. 4, it is also possible to provide a circular recess section GHto trap foreign matters which have intruded into the ventilation groove G. With this, the foreign matters which have intruded into the ventilation groove G cannot easily to arrive at the internal space18.

As described above, in Embodiment 1, by preventing airtight of the internal space18of the image pickup package10, it is possible to prevent breakage of the camera module1caused by thermal expansion of gas in the internal space18or fogginess of the glass substrate17because of gas or ions generated in the inside. Further, instead of providing a through hole for ventilation in a region where the solid state image pickup element13is provided, the ventilation groove G is provided on a plan surface of the sensor cover14to which the glass substrate17is adhered. This prevents inclination of the solid state image pickup element13caused by providing of the through hole, and can reduce fraction defective of the camera module1. Further, in a case where application of the adhesive16is performed by an automatic machine, it is possible to easily set a range of application by designating a line of the ventilation groove G with use of an image recognition function.

(Modified Example of Ventilation Groove of Camera Module)

The following description will discuss a modified example of the ventilation groove G of the camera module1with reference to (a) ofFIG. 5, (b) ofFIG. 5to (a) ofFIG. 8, (b) ofFIG. 8. (a) ofFIG. 5is a plan view illustrating a configuration of a modified example of the image pickup package10of the camera module1other than the glass substrate17. (b) ofFIG. 5is a cross-sectional view taken along the arrows X-X of (a). (a) ofFIG. 6is a plan view illustrating a configuration of a modified example of the image pickup package10of the camera module1, that is, a plan view illustrating a configuration in which the glass substrate17is provided. (b) ofFIG. 6is a cross-sectional view taken along the arrows X-X of (a). (a) ofFIG. 7is a plan view illustrating a configuration of another modified example of the image pickup package of the camera module. (b) ofFIG. 7is a cross-sectional view taken along the arrows Y-Y of (a). (a) ofFIG. 8is a plan view illustrating a configuration of still another modified example of the image pickup package of the camera module. (b) ofFIG. 8is a cross-sectional view taken along the arrows Y-Y of (a).

In (a) ofFIG. 2, (b) ofFIG. 2, (a) ofFIG. 3, and (b) ofFIG. 3, a single ventilation groove G is provided. However, in the camera module1of Embodiment 1, it is possible to form recess grooves S, S along the ventilation groove G on both sides of the single ventilation groove G as shown in (a) ofFIG. 5and (b) ofFIG. 5.

That is, in the configuration of the modified example, three straight grooves are provided on a plan surface of the step section14bof the sensor cover14. The center groove is the ventilation groove G for releasing, to the outside, gas and ions generated from the adhesives12,16in the internal space18of the image pickup package10. The two grooves on the both sides of the ventilation groove G are the recess grooves S, S provided to prevent the adhesive16from flowing into the ventilation groove G. The recess grooves S, S, as well as the ventilation groove G, are also structured so that the internal space18communicates with the outside of the sensor cover14.

Also in this modified example, the application of the adhesive16is performed to surround the opening14aas shown in (a) ofFIG. 5, however, the adhesive16is applied near the front recess grooves S, S.

In the configuration of this modified example, in view of the purpose of placing the ventilation groove G, the depth of the ventilation groove G is ideally a minimum value that can release gas present in the internal space18and prevent intrusion of foreign matters from the outside.

Therefore, in consideration of providing precision of the ventilation groove G, the depth is appropriately about 0.015 mm to 0.030 mm. Since foreign matters intrude if the depth of the recess grooves S, S is too large, the depth is set to be the same as that of the ventilation groove G, i.e., 0.015 mm to 0.030 mm.

All the ventilation groove G and the recess grooves S, S have a length of 0.2 mm to 1.0 mm and a width of 0.1 mm to 0.5 mm.

In the above configuration, in a case where the glass substrate17is mounted on the sensor cover14, as shown in (a) ofFIG. 6and (b) ofFIG. 6, the area of the adhesive16applied to the plan surface of the step section14bof the sensor cover14is expanded. However, the surplus adhesive16is flown into the recess grooves S, S and is not flown into the ventilation groove G.

In the above modified example, the recess grooves S, S, as well as the ventilation groove G, are structured so that the internal space18communicates with the outside of the sensor cover14. However, the recess grooves S, S are not always necessary to be structured as described above, and, for example, the recess grooves S, S can be shortened by blocking one end sections of the recess grooves S, S.

That is, a purpose of providing the recess grooves S, S is, as described above, to prevent the adhesive16on which the glass substrate17is mounted from flowing to the ventilation groove G, and the inflow of the adhesive16can be prevented more effectively as the recess grooves S, S become deeper. However, as shown in (a) ofFIG. 6and (b) ofFIG. 6, in a case where the recess grooves S, S, as well as the ventilation groove G, has the internal space18communicating with the outside of the sensor cover14, a possibility of intrusion of foreign matters into the internal space18becomes high if the recess grooves S, S become deeper.

In view of this, as shown in, for example, (a) ofFIG. 7and (b) ofFIG. 7, recess grooves S1, S1are provided on the sensor cover14so that the recess grooves S1, S1are positioned inside an outer periphery of the glass substrate17and communicate with the internal space18. In this configuration example, the recess grooves S, S are shortened and the recess grooves S1, S1are completely covered with the glass substrate17.

With this configuration, even if the recess grooves S1becomes deeper, there is a very low possibility that foreign matters intrude through the recess grooves S1, S1. In this case, the recess grooves S1, S1are set to have a length of 0.1 mm to 0.3 mm. The recess groove23are set to have a depth of 0.015 mm to 0.1 mm and a width of 0.1 mm to 0.5 mm. The reason why the length of the recess grooves S1, S1is shortened, i.e., 0.1 mm to 0.3 mm is that the recess grooves S1, S1are completely covered with the glass substrate17in consideration of a clearance between the glass substrate17and the plan surface of the step section14bof the sensor cover14on which the glass substrate17is mounted. That is, in a case where the adhesive16is not fully filled between the plan surface of the step section14band a back surface of the glass substrate17of a blocked section of each of the recess grooves S1, S1, i.e., in a case where there is a gap which is not filled with the adhesive16therebetween, the recess grooves S1, S1are not blocked. In this state, in a case where the glass substrate17is mounted on the sensor cover14, a mounting location of the glass substrate17is slightly shifted and the end sections of the recess grooves S1, S1are not covered with the glass substrate17, i.e., the end sections are exposed, a possibility of intrusion of foreign matters into the recess grooves S1, S1becomes high. Therefore, it is necessary to cover the recess grooves S1, S1with glass substrate17for certain by shortening the recess grooves S1, S1.

Meanwhile, as shown in (a) ofFIG. 8and (b) ofFIG. 8, recess grooves S2, S2can be also positioned outside the opening14aof the sensor cover14and communicate with the outside of the sensor cover14.

In this case, the recess grooves S2, S2are shortened by providing blocked sections on a side of the internal space18. As a result, the recess grooves S2, S2can prevent foreign matters from intruding from the outside through the recess grooves S2, S2because the recess grooves S2, S2has no air-permeability. By providing deeper recess grooves S2, S2, the inflow of the adhesive16can be prevented more effectively. In the configuration of (a) ofFIG. 7and (b) ofFIG. 7, the recess grooves S1, S1need to be shortened since the recess grooves S1, S1need to be covered with the glass substrate17for certain. However, in the configuration of (a) ofFIG. 8and (b) ofFIG. 8, since the recess grooves S2, S2do not need to be completely covered with the glass substrate17, the length of the recess grooves S2, S2can be larger than the length of the recess grooves S1, S1of the configuration example illustrated in (a) ofFIG. 7and (b) ofFIG. 7. Therefore, the recess grooves S2, S2are set to have a larger length, i.e., a length of 0.2 mm to 0.9 mm. Further, the recess grooves S2, S2are set to have a depth of 0.015 mm to 0.1 mm and a width of 0.1 mm to 0.5 mm.

As a result, the recess grooves S2, S2can function more effectively.

Accordingly, in Embodiment 1, by providing a plurality of grooves in a portion where the plan surface of the sensor cover14of the image pickup package10is adhered to the glass substrate17, the ventilation groove G enabling air-permeability between the inside of the image pickup package10and open air is provided, which can prevent fogginess in the inside of the camera module1caused by change in atmospheric pressure and in temperature. Further, provision of the recess grooves S, S, recess grooves S1, S1, or the recess grooves S2, S2on the both sides of the ventilation groove G prevents clogging of the ventilation groove G caused by the inflow of the adhesive16. Furthermore, effective placement of the recess grooves S, S, the recess grooves S1, S1, or the recess grooves S2, S2for preventing clogging of the ventilation groove G with the adhesive16improves reliability of the camera module1.

As described above, by adhering the glass substrate17to the sensor cover14so that the glass substrate17covers the opening14aof the sensor cover14for covering the solid state image pickup element13mounted on the wiring substrate11, which opening14ais provided above the solid state image pickup element13, the camera module1of Embodiment 1 includes: the image pickup package10in which the wiring substrate11, the sensor cover14, and the glass substrate17define the internal space18; and the image pickup lens21provided above the glass substrate17of the image pickup package10. On the adhesive surface of the glass substrate17above the sensor cover14, at least one ventilation groove G so that the internal space18communicates with open air is provided.

As a result, the ventilation groove G is provided not on the wiring substrate11below the solid state image pickup element13, but is provided between the sensor cover14and the glass substrate17, i.e., is provided on the plan surface of the step section14bof the sensor cover14to which the glass substrate17is adhered. Therefore, it is not necessary to partially provide adhesive layers on a bottom of the solid state image pickup element13, which is an inclination factor of the solid state image pickup element13. That is, in Embodiment 1, the adhesive12is applied to a whole surface of a bottom surface of the solid state image pickup element13.

The at least one ventilation groove G provided on the plan surface of the step section14bof the sensor cover14to which the glass substrate17is adhered has not only a function of the ventilation groove G which allows the internal space18in which the solid state image pickup element13is provided to communicate with open air, but also a function as a recess groove to prevent clogging of the ventilation groove G with the adhesive16, which can be caused by expansion of the adhesive16when the glass substrate17is pressed to the sensor cover14. That is, for example, even if the adhesive16intrudes into the ventilation groove G, since the ventilation groove G is a recess section, the recess section is not fully filled with the adhesive16by managing an amount of the adhesive16as appropriate, and a slight gap16astill exists in a top surface of the recess section because of capillarity. As a result, the ventilation groove G serves as the recess groove of the adhesive16. Because of the gap16a, air-permeability can be obtained.

Accordingly, the present invention can provide the camera module1which can obtain air-permeability between the internal space18of the image pickup package10and open air while the solid state image pickup element13is not being inclined.

In the camera module1of Embodiment 1, on the each side of the ventilation groove G, the recess grooves S, S, the recess grooves S1, S1, or the recess grooves S2, S2for preventing inflow of the adhesive16into the ventilation groove G are preferably provided along the ventilation groove G.

With this structure, when the glass substrate17is adhered to the sensor cover14, the adhesive16flows into the recess grooves S, S, the recess grooves S1, S1, or the recess grooves S2, S2provided along the both sides of the ventilation groove G and does not flow into the ventilation groove G sandwiched by the recess grooves S, S, the recess grooves S1, S1, or the recess grooves S2, S2. Therefore, it is possible to further prevent the adhesive16from blocking the ventilation groove G.

In the camera module1of Embodiment 1, the ventilation groove G has a depth of 0.01 mm to 0.1 mm. This makes it possible so that the internal space18communicates with open air, and therefore air-permeability can be obtained.

In the camera module1of Embodiment 1, the ventilation groove G has a straight shape, a circular arc shape, or a curved shape on a plan view. Therefore, in a case where the ventilation groove G has a straight shape on the plan view, it is possible to satisfactorily obtain air-permeability between the internal space18and the outside of the sensor cover14. Further, in a case where the ventilation groove G has a circular arc shape or a curved shape on the plan view, foreign matters which have intruded into the ventilation groove G cannot easily arrive at the internal space18.

In the camera module1of Embodiment 1, it is preferable that the ventilation groove G have the recess section GHfor trapping foreign matters which have intruded into the inside of the ventilation groove G.

With this structure, the recess section GHis provided on a bottom surface of the ventilation groove G, so that, even if foreign matters intrude into the ventilation groove G, the foreign matters are trapped by the recess section GH. This makes it possible to further prevent foreign matters from arriving at the internal space18.

In the camera module1of Embodiment 1, the recess grooves S, S can be provided so that the internal space18communicates with open air. With this, the recess grooves S, S also have a function as the ventilation groove G. Therefore, because at least three ventilation grooves G exist, it is possible to obtain satisfactory air-permeability between the internal space18and the outside of the sensor cover14even if the adhesive16intrudes into a part of the ventilation grooves G.

In the camera module1of Embodiment 1, the recess grooves S1, S1can be also provided on the sensor cover14in such a manner as to be positioned inside the outer periphery of the glass substrate17and communicate with the internal space18.

By blocking open-air-side ends of the recess grooves S, S, it is possible to prevent foreign matters from intruding through the recess grooves S1, S1.

In the camera module1of Embodiment 1, the recess grooves S2, S2can be positioned outside the opening of the sensor cover14and communicate with open air. By blocking internal-space-18-side ends of the recess grooves S, S, it is possible to prevent foreign matters from intruding through the recess grooves S2, S2.

Note that the present invention is not limited to the embodiment, and may be varied in many ways within the scope of the present invention.

For example, as illustrated inFIG. 9, the present invention can be applied to a camera module including a cover body integrally provided to have both a lens holder function and a sensor cover function. Although not shown, by providing the ventilation groove on a surface to which a transparent plate is adhered, the present invention can be also applied to a camera module including a cover body in which a lens driving mechanism including the image pickup lens21is mounted directly on the wiring substrate11.

The following description will discuss another embodiment of the present invention with reference toFIG. 10. Note that a configuration other than the following configuration described in Embodiment 2 is the same as that in Embodiment 1. For the sake of easy explanation, members having the like functions as the figures described in Embodiment 1 are denoted by the like reference signs and the detailed description thereof is omitted.

A camera module1A of Embodiment 2 is different from the camera module1having the ventilation groove G and the recess grooves S, S, which has been described inFIG. 6of Embodiment 1, in that the ventilation groove G is non-linear or curved as illustrated inFIG. 10.

That is, as illustrated inFIG. 10, by adhering the glass substrate17serving as a transparent plate to the sensor cover14so that the glass substrate17covers the opening14aof the sensor cover14serving as a cover body for covering the solid image pickup element13serving as an image pickup element mounted on the wiring substrate11serving as a substrate, which opening14ais provided above the solid image pickup element13, the camera module1A of Embodiment 2 includes: the image pickup package10in which the wiring substrate11, the sensor cover14, and the glass substrate17define the internal space18; and the image pickup lens21provided above the glass substrate17in the image pickup package10. Further, at least one ventilation groove G1for allowing the internal space18to communicate with open air is provided on the adhesive surface of the glass substrate17above the sensor cover14. On the both sides of the ventilation groove G1, the recess grooves S, S for preventing inflow of the adhesive16into the ventilation groove G1are provided along the ventilation groove G1.

The ventilation groove G1has a circular arc or curved shape on a plan view, and the ventilation groove G1is provided so that the internal space18communicates with the open air. Note that the ventilation groove G1illustrated inFIG. 10has a curved shape, however, the shape on the plan view is not limited thereto, and may be a circular arc shape.

With this configuration, the ventilation groove G1has a circular arc shape or a curved shape on the plan view, so that foreign matters which have intruded into the ventilation groove G1cannot easily arrive at the internal space18.

The recess grooves S, S is provided so that the internal space18communicates with open air, so that the recess grooves S, S also have a function as a ventilation groove. Therefore, because at least three ventilation grooves G exist, it is possible to obtain satisfactory air-permeability between the internal space18and the outside of the sensor cover14even if the adhesive16intrudes into a part of the ventilation grooves G.

The following description will discuss still another embodiment of the present invention with reference toFIG. 11. Note that a configuration other than the following configuration described in Embodiment 3 is the same as that in Embodiments 1 and 2. For the sake of easy explanation, members having the like functions as the figures described in Embodiment 1 and 2 are denoted by the like reference signs and the detailed description thereof is omitted.

The camera module1B of Embodiment 3 is different from the camera module1having the ventilation groove G and the recess grooves S1, S1, which has been described inFIG. 7of Embodiment 1, in that the ventilation groove G is curved as illustrated inFIG. 11.

In other words, as illustrated inFIG. 11, the camera module1B of Embodiment 3 is structured such that, in the camera module1A having the curved ventilation groove G1and the recess grooves S, S, which has been described inFIG. 10of the Embodiment 2, the recess grooves S1, S1are completely covered with the glass substrate17by providing the recess grooves S1, S1which have been provided by shortening the recess grooves S, S. Therefore, the recess grooves S1, S1are different from the recess grooves S, S in that the recess grooves S1, S1are provided on the sensor cover14so as to be positioned inside the outer periphery of the glass substrate17and the recess grooves S1, S1communicate with the internal space18.

That is, as illustrated inFIG. 11, by adhering the glass substrate17serving as a transparent plate to the sensor cover14so that the glass substrate17covers the opening14aof the sensor cover14serving as a cover body for covering the solid image pickup element13serving as an image pickup element mounted on the wiring substrate11serving as a substrate, which opening14ais provided above the solid image pickup element13, the camera module1B of Embodiment 3 includes: the image pickup package10in which the wiring substrate11, the sensor cover14, and the glass substrate17define the internal space18; and the image pickup lens21provided above the glass substrate17in the image pickup package10. Further, at least one ventilation groove G1for allowing the internal space18to communicate with open air is provided on a plane of the sensor cover14on which plane the glass substrate17is attached. On the each side of the ventilation groove G1, the recess grooves S1, S1for preventing inflow of the adhesive16into the ventilation groove G1are provided along the ventilation groove G1.

The ventilation groove G1has a circular arc shape or a curved shape on the plan view, and is provided so that the internal space18communicates with open air, and the recess grooves S1, S1are provided on the sensor cover14in such a manner as to be positioned inside the outer periphery of the glass substrate17and communicate with the internal space18.

Therefore, the ventilation groove G1has a circular arc shape or a curved shape on the plan view, so that foreign matters which have intruded into the ventilation groove G1cannot easily arrive at the internal space18.

In the camera module1B of Embodiment 3, the recess grooves S1, S1are provided on the sensor cover14in such a manner as to be positioned inside the outer periphery of the glass substrate17and communicate with the internal space18.

With this configuration, even if the recess grooves S1becomes deeper, there is a very low possibility that foreign matters intrude through the recess grooves S1, S1. In this case, the recess grooves S1, S1are set to have a length of 0.1 mm to 0.3 mm. The recess groove S1are set to have a depth of 0.015 mm to 0.1 mm and a width of 0.1 mm to 0.5 mm. The reason why the length of the recess grooves S1, S1is shortened, i.e., 0.1 mm to 0.3 mm is that the recess grooves S1, S1are completely covered with the glass substrate17in consideration of a clearance between the glass substrate17and the plan surface of the step section14bof the sensor cover14on which the glass substrate17is mounted. That is, in a case where the adhesive16is not fully filled between the plan surface of the step section14band a back surface of the glass substrate17of a blocked section of each of the recess grooves S1, S1, i.e., in a case where there is a gap which is not filled with the adhesive16therebetween, the recess grooves S1, S1are not blocked. In this state, in a case where the glass substrate17is mounted on the sensor cover14, a mounting location of the glass substrate17is slightly shifted and the end sections of the recess grooves S1, S1are not covered with the glass substrate17, i.e., the end sections are exposed, a possibility of intrusion of foreign matters into the recess grooves S1, S1becomes high. Therefore, it is necessary to cover the recess grooves S1, S1with glass substrate17for certain by shortening the recess grooves S1, S1.

The following description will discuss still another embodiment of the present invention with reference toFIG. 12. Note that a configuration other than the following configuration described in Embodiment 4 is the same as that in Embodiments 1 to 3. For the sake of easy explanation, members having the like functions as the figures described in Embodiment 1 to 3 are denoted by the like reference signs and the detailed description thereof is omitted.

The camera module1C of Embodiment 4 is different from the camera module1having the ventilation groove G and the recess grooves S2, S2, which has been described inFIG. 8of Embodiment 1, in that the ventilation groove G is curved as illustrated inFIG. 12.

In other words, as illustrated inFIG. 12, the camera module1C of Embodiment 4 is different from the camera module1A having the curved ventilation groove G1and the recess grooves S, S, which has been described inFIG. 10, in that the recess grooves S2, S2(i) are provided by shortening the recess grooves S1, S1and (ii) are positioned outside the opening14aof the sensor cover14to be communicate with open air.

That is, as illustrated inFIG. 12, by adhering the glass substrate17serving as a transparent plate to the sensor cover14so that the glass substrate17covers the opening14aof the sensor cover14serving as a cover body for covering the solid image pickup element13serving as an image pickup element mounted on the wiring substrate11serving as a substrate, which opening14ais provided above the solid image pickup element13, the camera module1C of Embodiment 4 includes: the image pickup package10in which the wiring substrate11, the sensor cover14, and the glass substrate17define the internal space18; and the image pickup lens21provided above the glass substrate17in the image pickup package10. Further, at least one ventilation groove G1for allowing the internal space18to communicate with open air is provided on the plane of the sensor cover14on which plane the glass substrate17is attached. On the each side of the ventilation groove G1, The recess grooves S2, S2for preventing inflow of the adhesive16into the ventilation groove G1are provided along the ventilation groove G1.

The ventilation groove G1has a circular arc shape or a curved shape on the plan view, and is provided so that the internal space18communicates with open air, the recess grooves S2, S2are positioned outside the opening14aof the sensor cover14to be communicate with open air.

Therefore, the ventilation groove G1has a circular arc shape or a curved shape on the plan view, so that foreign matters which have intruded into the ventilation groove G1cannot easily arrive at the internal space18.

In the camera module1C of Embodiment 4, the recess grooves S2, S2are positioned outside the opening14aof the sensor cover14to be communicate with open air.

With this configuration, the recess grooves S2, S2are shortened by providing blocked sections on a side of the internal space18. As a result, the recess grooves S2, S2can prevent foreign matters from intruding from the outside through the recess grooves S2, S2because the recess grooves S2, S2has no air-permeability. By providing deeper recess grooves S2, S2, the inflow of the adhesive16can be prevented more effectively. In the configuration of (a) ofFIG. 11and (b) ofFIG. 11, the recess grooves S1, S1need to be shortened since the recess grooves S1, S1need to be covered with the glass substrate17for certain. However, in the configuration of (a) ofFIG. 12and (b) ofFIG. 12, since the recess grooves S2, S2do not need to be completely covered with the glass substrate17, the length of the recess grooves S2, S2can be larger than the length of the recess grooves S1, S1of the configuration example illustrated in (a) ofFIG. 11and (b) ofFIG. 11. Therefore, the recess grooves S2, S2are set to have a larger length, i.e., a length of 0.2 mm to 0.9 mm. Further, the recess grooves S2, S2are set to have a depth of 0.015 mm to 0.1 mm and a width of 0.1 mm to 0.5 mm.

As a result, the recess grooves S2, S2can function more effectively.

Each of the camera modules1,1A,1B, and1C of an aspect 1 includes: an image pickup package10including a substrate (wiring substrate11), an image pickup element21on the substrate (wiring substrate11), and a cover body (sensor cover14) for covering the image pickup element (solid image pickup element13) on the substrate (wiring substrate11), a transparent plate (glass substrate17) being attached to the cover body in such a manner that the transparent plate (glass substrate17) covers an opening of the cover body (sensor cover14) which opening is above the image pickup element (solid image pickup element13), so that the substrate (wiring substrate11), the cover body (sensor cover14), and the transparent plate (glass substrate17) define an internal space18; and an image pickup lens provided above the transparent plate of the image pickup package10, wherein at least one ventilation groove G or G1for allowing the internal space18to communicate with open air is provided on a plane of the cover body (sensor cover14) on which plane the transparent plate (glass substrate17) is attached.

According to the above invention, the camera module includes an image pickup package including a substrate, an image pickup element on the substrate, and a cover body for covering the image pickup element on the substrate, a transparent plate being attached to the cover body in such a manner that the transparent plate covers an opening of the cover body which opening is above the image pickup element, so that the substrate, the cover body, and the transparent plate define an internal space; and an image pickup lens provided above the transparent plate of the image pickup package.

In a case of the camera module having the above configuration, thermal expansion of gas in the internal space may occur due to a rise in temperature, with the result that the adhesive may come off. Therefore, it is necessary to provide a ventilation hole for allowing the internal space of the image pickup package to communicate with open air. In this case, in a case where the ventilation hole is provided to be placed directly under the image pickup element and the image pickup element and the wiring substrate are partially adhered to each other like the camera module disclosed in Patent Literature 1, the image pickup element may be inclined due to the thickness of the adhesive layers.

In view of the circumstances, in the present invention, at least one ventilation groove is provided on the plane of the cover body on which plane the transparent plate is attached, so that the internal space communicates with open air.

As a result, the ventilation groove is provided not on the wiring substrate directly under the image pickup element, but is provided between the cover body and the transparent plate, i.e., is provided on a plan surface section of the cover body to which the transparent plate is adhered. Therefore, it is not necessary to partially provide an adhesive layer on a bottom of the solid state image pickup element, which is an inclination factor of the image pickup element.

The at least one ventilation groove provided on the plan surface of the cover body to which the transparent plate is adhered has not only a function of the ventilation groove which allows the internal space in which the image pickup element is provided to communicate with open air but also a function as a recess groove to prevent clogging of the ventilation groove with the adhesive, which clogging could be caused by expansion of the adhesive when the transparent plate is pressed to the cover body. That is, for example, even if the adhesive intrudes into the ventilation groove, since the ventilation groove is a recess section, the recess section is not fully filled with the adhesive by managing an amount of the adhesive as appropriate, and a slight gap still exists in a top surface of the recess section because of capillarity. As a result, the ventilation groove serves as the recess groove of the adhesive. Further, because of the gap, air-permeability can be obtained.

Accordingly, the present invention can provide the camera module which can obtain air-permeability between the internal space of the image pickup package and open air while the image pickup element is not being inclined.

In each of the camera modules1,1A,1B, and1C of an aspect 2 of the present invention according to the camera module1of the aspect 1, on each side of the ventilation groove G or G1, the recess groove S, S1, or S2for preventing the adhesive16from flowing into the ventilation groove G or G1is provided along the ventilation groove G or G1.

With this structure, when the transparent plate is adhered to the cover body, the adhesive flows into the recess grooves provided on each side of the ventilation groove. This makes it possible to prevent the adhesive from flowing into the ventilation groove sandwiched by the recess grooves. Therefore, it is possible to further prevent the adhesive from blocking the ventilation groove.

In each of the camera modules1,1A,1B, and1C of an aspect 3 of the present invention according to the camera module1of the aspect 1 or 2, the ventilation groove G or G1has a depth of 0.01 mm to 0.1 mm.

This makes it possible to allows the internal space to communicate with the outside of the cover body, and therefore the camera module can obtain air-permeability.

In each of the camera modules1,1A,1B, and1C of an aspect 4 of the present invention according to the camera module1,2, or3of the aspect 1, 2, or 3, the ventilation groove G or G1has a straight shape, a circular arc shape, or a curved shape on the plan view.

This makes it possible to obtain satisfactory air-permeability between the internal space and the outside of the cover body in a case where the ventilation groove has a straight shape on the plan view. Further, in a case where the ventilation groove has a circular arc shape or a curved shape on the plan view, foreign matters which have intrude into the ventilation groove cannot easily arrive at the internal space.

In the camera module1,1A,1B, and1C of an aspect 5 of the present invention according to the camera module1according to any one of the aspects 1 to 4, the ventilation groove G or G1has a recess section GHfor trapping foreign matters which have intruded into an inside of the ventilation groove G or G1.

Therefore, since the recess section is provided on a bottom surface of the ventilation groove, foreign matters are trapped by the recess section even if the foreign matters intrude into the ventilation groove. This makes it possible to further prevent foreign matters from arriving at the internal space.

In the camera module1of an aspect 6 of the present invention according to the camera module1of the aspect 2, the recess groove S is provided so that the internal space18communicates with open air.

Therefore, the recess groove also has a function as a ventilation groove. Therefore, at least three ventilation grooves exist, so that it is possible to obtain satisfactory air-permeability between the internal space and the outside of the cover coy (sensor cover14) even if the adhesive flows into a part of the ventilation grooves.

In the camera module1,1A,1B, and1C of an aspect 7 of the present invention according to the camera module1of the aspect 2, the recess groove S1is provided on the cover body (sensor cover14) in such a manner as to be positioned inside an outer periphery of the transparent plate (glass substrate17) and communicates with the internal space18.

Therefore, by blocking an open-air-side end of the recess groove, foreign matters can be prevented from intruding through the recess groove.

In the camera module1of an aspect 8 of the present invention according to the camera module1of the aspect 2, the recess groove S2is provided the on the cover body (sensor cover14) in such a manner as to be positioned outside the opening14aof the cover body (sensor cover14) and communicates with open air.

Therefore, by blocking an internal-space-side end of the recess groove, foreign matters can be prevented from intruding through the recess groove.

In the camera module1A of an aspect 9 of the present invention according to the camera module1of aspect 2, the ventilation groove G1has a circular arc or a curved shape on a plan view; and the recess groove S is provided so that the internal space18communicates with open air.

Therefore, since the ventilation groove has a circular arc shape or a curved shape on a plan view, foreign matters which have intruded into the ventilation groove cannot easily arrive at the internal space.

Further, since the recess groove is provided so that the internal space communicates with open air, the recess groove also has a function as a ventilation groove. Therefore, at least three ventilation grooves exist, so that it is possible to obtain satisfactory air-permeability between the internal space and the outside of the sensor cover even if the adhesive intrudes into a part of the ventilation grooves.

In the camera module1B of aspect 10 of the present invention according to the camera module1of aspect 2, the ventilation groove G1has a circular arc shape or a curved shape on the plan view, and the recess groove S1is provided on the cover body (sensor cover14) so as to be positioned inside an outer periphery of the transparent plate (glass substrate17) and communicates with the internal space18.

Therefore, since the ventilation groove has a circular arc shape or a curved shape on the plan view, foreign matters which have intruded into the ventilation groove cannot easily arrive at the internal space.

Further, since the recess groove is provided on the cover body so as to be positioned inside the outer periphery of the transparent plate and communicates with the internal space, the open-air-side end of the recess groove is blocked. This makes it possible to prevent foreign matters from intruding from the recess groove.

In the camera module1C of an aspect 11 of the present invention according to the camera module1of the aspect 2, the ventilation groove G1has a circular arc shape or a curved shape on a plan view; and the recess groove S2is provided outside the opening14aof the cover body (sensor cover14) and communicates with open air.

Therefore, since the ventilation groove has a circular arc shape or a curved shape on the plan view, foreign matters which have intruded into the ventilation groove cannot easily arrive at the internal space.

Further, since the recess groove is provided outside the opening of the cover body and communicates with open air, the inner-space-side end of the recess groove is blocked. This makes it possible to prevent foreign matters from intruding from the recess groove.

INDUSTRIAL APPLICABILITY

The present invention is applicable to a camera module for use in capturing in a camera-equipped mobile phone, digital camera, security camera, television camera, or the like.

REFERENCE SIGNS LIST