JP7457622B2 - Camera module and in-vehicle camera device - Google Patents

Description

The present invention relates to a camera module and a vehicle-mounted camera device.

Camera modules have come to be installed in various devices such as in-vehicle camera devices. In such a camera module, it is necessary to maintain the positional relationship between the optical lens and the image sensor and to fix them accurately so that the quality of photographing is not impaired.

Patent Document 1 discloses a pedestal mount for holding a lens, in which a plurality of grooves are formed in an outer circumferential rib fixed to an FPC board in a direction perpendicular to the longitudinal direction thereof, and the pedestal mount and the FPC board are bonded together. It is described that the adhesive strength can be increased by increasing the area.

JP2007-300428A

The configuration described in Patent Document 1 makes it impossible to fix the positional relationship between the optical lens and the image sensor with high precision.

A camera module according to the present invention includes a holding member that holds an optical lens therein, a substrate on which an image sensor is arranged, and a fixing material containing a photocuring agent that fixes the bottom side of the holding member and the substrate. a vertically elongated groove extending from the bottom side to the tip side of the holding member is formed on the outer circumferential surface of the bottom side of the holding member , and the fixing material coated and present on the inside of the holding member is The concentration of the photocuring agent is higher than that of the fixing material applied to the outside of the holding member .

According to the present invention, it is possible to maintain and fix the positional relationship between the optical lens and the image sensor with high precision.

It is a perspective view of a camera module. 1 is a vertical cross-sectional view of a camera module including a housing. 1A to 1C are diagrams illustrating a manufacturing process of a camera module. 3 is a longitudinal cross-sectional view of a camera module in Comparative Example 1. FIG. FIG. 3 is a longitudinal cross-sectional view of the camera module in the first embodiment. FIG. 7 is a longitudinal cross-sectional view of a camera module in a second embodiment. FIG. 6 is a longitudinal cross-sectional view of the camera module in the second embodiment, and is a diagram illustrating the curing and contraction force of the fixing material. 3 is a longitudinal cross-sectional view of a camera module in Comparative Example 2. FIG. FIG. 7 is a cross-sectional view of a camera module in a third embodiment. It is a perspective view of a camera device.

Embodiments of the present invention will be described below with reference to the drawings. The following description and drawings are examples for explaining the present invention, and are omitted and simplified as appropriate for clarity of explanation. The present invention can also be implemented in various other forms. Unless specifically limited, each component may be singular or plural.

The position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

When there are multiple components having the same or similar functions, the same reference numerals may be given different suffixes for explanation. However, if there is no need to distinguish between these multiple components, the subscripts may be omitted in the description.

[First embodiment]
FIG. 1 is a perspective view of a camera module 1000.
The camera module 1000 includes a holding member 1120 that holds an optical lens 1110 (see FIG. 2 described later) therein, a substrate 1140 on which an image sensor 1130 (see FIG. 2 described later) is arranged, a bottom side of the holding member 1120, and a substrate. 1140 and a fixing member 1150 for fixing the fixing member 1140.

On the outer peripheral surface 1124 on the bottom side of the holding member 1120, a plurality of vertically elongated grooves 1125 are formed from the bottom side of the holding member 1120 toward the tip side. The outer peripheral surfaces 1124 on which the grooves 1125 are formed are the opposing surfaces of the holding member 1120. In this embodiment, an example in which the grooves 1125 are formed on each of the two opposing outer peripheral surfaces 1124 of the holding member 1120 will be described, but the grooves 1125 may be formed on each of the four outer peripheral surfaces 1124 of all of the holding member 1120. The holding member 1120 has a cubic shape on the bottom side and a cylindrical shape on the tip side, and forms a continuous space inside. In addition, the bottom side of the holding member 1120 will be described as a cubic shape, but it may also be cylindrical. In the case of a cylindrical shape, the grooves 1125 are formed on two outer peripheral surfaces located at 180 degrees of the cylinder, or on four outer peripheral surfaces located at 90 degrees of the cylinder.

The fixing material 1150 contains a photocuring agent and a thermosetting agent, and is applied between the bottom side of the holding member 1120 and the substrate 1140 and permeated into the groove 1125, and after positioning the holding member 1120 and the substrate 1140. , hardened by light irradiation treatment and heat treatment. Note that the fixing material 1150 contains at least a photocuring agent, and may be cured by light irradiation treatment instead of heat treatment.

A housing 2000 is attached to the camera module 1000 from the direction of arrow A, and protects each member of the camera module 1000 by covering each member, and fixes the camera module 1000 to a device (not shown).

FIG. 2 is a longitudinal cross-sectional view of the camera module 1000 including the housing 2000.
The holding member 1120 fixes and holds the optical lens 1110 inside its cylindrical shape. An image sensor 1130 is arranged on the substrate 1140. A cubic-shaped bottom surface 1121 of the holding member 1120 is in contact with a fixing member 1150 and is fixed to the substrate 1140 by the fixing member 1150. The holding member 1120 and the substrate 1140 are fixed in such a state that the optical axis P of the optical lens 1110 is substantially perpendicular to the imaging surface of the image sensor 1130 and the focal point of the optical lens 1110 is substantially aligned with the image sensor 1130. Ru.

A groove 1125 is formed in the outer peripheral surface 1124 of the holding member 1120 on the bottom side. This groove 1125 is open to the bottom side of the holding member 1120 and is formed vertically along the optical axis P of the optical lens 1110.

The fixing material 1150 is a material containing a photocuring agent that is activated by irradiation with light energy to induce a curing reaction, and is applied in a melt state onto the substrate 1140 during manufacturing. At this time, the fixing material 1150 in a molten state penetrates into the groove 1125 due to capillary action, and penetrates toward the distal end side along the groove 1125. Then, with the fixing position of the holding member 1120 and the substrate 1140 determined, the fixing material 1150 is cured by irradiating light energy from the outside, and the holding member 1120 and the substrate 1140 are fixed.

Then, the housing 2000 is attached to the camera module 1000 to which the holding member 1120 and the substrate 1140 are fixed. Thereby, the camera module 1000 images the optical information from the optical lens 1110 onto the image sensor 1130 to obtain an image.

FIG. 3 is a diagram showing the manufacturing process of the camera module 1000. 3(A) shows a process of applying the fixing material 1150, and FIG. 3(B) shows a process of curing the fixing material 1150.
As shown in FIG. 3A, in the step of applying the fixing material 1150, the fixing material 1150 in a molten state is applied onto the substrate 1140 around the image sensor 1130 and in alignment with the bottom surface 1121 of the holding member 1120. Apply.

Next, in a step of curing the fixing material 1150 shown in FIG. 3B, the holding member 1120 is fixed to the substrate 1140. Here, the positional relationship between the optical lens 110 and the image sensor 1130 is adjusted to match the optical axis P, and the fixing material 1150 in a molten state is irradiated with light at the adjusted position to solidify the fixing material 1150. That is, an active alignment process is used.

FIG. 4 is a longitudinal cross-sectional view of a camera module 1000' in Comparative Example 1, and shows an example in which this embodiment is not applied.
In Comparative Example 1 shown in FIG. 4, no groove is formed on the outer circumferential surface 1124 of the holding member 1120 on the bottom side. Therefore, the fixing material 1150 is infiltrated only into the vicinity of the bottom surface 1121 of the holding member 1120. That is, the fixing material 1150a is infiltrated around the outside of the holding member 1120, and the fixing material 1150b is infiltrated around the inside (image sensor side) of the holding member 1120 to approximately the same height.

The camera module 1000' includes an optical lens 1110 and an image sensor such that the optical axis P of the optical lens 1110 is perpendicular to the imaging surface of the imaging device 1130, and the focal position of the optical lens 1110 coincides with the imaging surface of the imaging device 1130. The positional relationship of elements 1130 is ideal.

In order to achieve such a positional relationship, when manufacturing the camera module 1000', the positional relationship between the optical lens 1110 and the image sensor 1130 is adjusted, and the fixing material 1150, which is in a molten state at the adjusted position, is solidified. By using an alignment process, desired optical performance is obtained.

In this active alignment process, light must be irradiated from the outside onto the fixing member 1150 while the optical lens 1110 and the image sensor 1130 are already assembled, but the light can only be irradiated to the outside of the holding member 1120. Since there is only the fixing material 1150a, and the fixing material 1150b inside the holding member 1120 (on the image sensor side) is in the shadow where no light hits, the fixing material 1150b is in an uncured state and may not be able to obtain sufficient adhesive strength. There is sex.

FIG. 5 is a vertical cross-sectional view of the camera module 1000 according to the present embodiment.
5, in this embodiment, a groove 1125 is formed in the outer peripheral surface 1124 on the bottom side of the holding member 1120. As already described with reference to FIGS. 1 and 2, this groove 1125 is open to the bottom side of the holding member 1120 and is formed vertically long along the optical axis P of the optical lens 1110.

Since the bottom surface side of the holding member 1120 is open, the groove 1125 has the effect of allowing the fixing material 1150 in a molten state to easily permeate into the inside of the groove 1125 by capillary action. Note that even if the bottom surface side of the holding member 1120 is not open, it is sufficient that the fixing material 1150 in a molten state can permeate into the inside of the groove 1125 by capillary action.
In addition, since the groove 1125 is formed vertically long toward the tip side of the holding member 1120 along the optical axis P of the optical lens 1110, there is an effect of reducing the influence of the curing contraction force of the fixing material 1150 on the optical axis P of the optical lens 1110. Note that the groove 1125 does not necessarily have to be formed along the optical axis P of the optical lens 1110, as long as it is formed vertically long toward the tip side of the holding member 1120.

In the present embodiment shown in FIG. 5, the fixing material 1150 is sucked into the groove 1125 by capillary action and permeates along the groove 1125 toward the distal end. Compared to the structure without the groove 1125 shown in Comparative Example 1 of FIG. 4, the area of contact with the outer peripheral surface 1124 of the holding member 1120 is increased. Therefore, the fixing material 1150a that has penetrated into the groove 1125 exists in a position that will not be shaded when irradiated with light from the outside, and can be easily hardened over a wide range by light irradiation treatment, increasing the adhesive strength. will improve. Furthermore, since the fixing material 1150a has a large contact area with the outer circumferential surface 1124 of the holding member 1120, sufficient adhesive strength can be obtained even with short-time light irradiation treatment.

After the fixing material 1150 is cured, the concentration of the light curing agent in the fixing material 1150b applied to the inside of the holding member 1120 is necessarily higher than that of the fixing material 1150a applied to the outside of the holding member 1120. become higher. Sufficient adhesive strength can be obtained by the fixing material 1150a outside the holding member 1120.

Fixing material 1150 contains a photocuring agent and a thermosetting agent. Although the fixing material 1150a is cured by the light irradiation process, the fixing material 1150b inside the holding member 1120 (on the image sensor side) may not be sufficiently exposed to light and may be in an uncured state. Therefore, by subjecting the camera module 1000 to heat treatment in the active alignment process, the fixing material 1150 containing a thermosetting agent is cured to further improve the adhesive strength.

Furthermore, since the grooves 1125 are provided on one opposing outer circumferential surface 1124 and the other opposing outer circumferential surface 1124 of the holding member 1120, the curing shrinkage force of the fixing material 1150 acts equally on both surfaces. Therefore, deviation of the optical axis P of the optical lens 1110 can be prevented, and the accuracy of the camera module 1000 can be improved.

According to this embodiment, when manufacturing the camera module 1000 using the active alignment process, the fixing material 1150 can be efficiently cured by external light irradiation, and the camera module 1000 can be made to have high strength and high precision. can contribute to

[Second embodiment]
A second embodiment will be described with reference to FIGS. 6 to 8.
Note that matters described in the first embodiment but not described in this embodiment are also applied to this embodiment unless there are special circumstances.

FIG. 6 is a longitudinal cross-sectional view of the camera module 1001 in this embodiment. In this embodiment, the depth of the groove 1125 is shallower on the tip side than on the bottom side of the holding member 1120. The other configurations are the same as those in FIGS. 1, 2, 3, and 5 described in the first embodiment, and the same parts are given the same reference numerals and the explanation thereof will be omitted.

As shown in FIG. 6, the groove 1125 formed in the outer circumferential surface 1124 on the bottom side of the holding member 1120 has a depth D2 on the tip side that is shallower than a depth D1 on the bottom side. The curing shrinkage force of the fixing material 1150 in this case will be explained with reference to FIG. 7.

FIG. 7 is a longitudinal cross-sectional view of the camera module 1001 in this embodiment, which is the same as FIG. 6, but is a diagram for explaining the curing and contraction force of the fixing material 1150.
In FIG. 7, the curing contraction forces Q1 and Q2 of the fixing material 1150 are schematically indicated by arrows. The curing shrinkage force Q1 of the fixing material 1150 is the curing shrinkage force on one opposing outer circumferential surface 1124 of the holding member 1120 in which the groove 1125 is formed, and the curing shrinkage force Q2 is the curing shrinkage force on the other opposing outer circumferential surface of the holding member 1120. 1124 shows the curing shrinkage force at 1124.

Since the depth of the groove 1125 is shallower on the tip side than on the bottom side of the holding member 1120, less fixing material 1150 penetrates into the tip side than on the bottom side of the groove 1125, and the amount of fixing material 1150 is reduced. There are fewer grooves 1125 on the tip side than on the bottom side. Therefore, the curing contraction forces Q1 and Q2 of the fixing material 1150 are smaller on the tip side of the groove 1125 than on the bottom side. As will be described below with reference to Comparative Example 2 in FIG. It is thought that this contributes most to the deviation of the axis P. In this embodiment, the amount of fixing material 1150 in the groove 1125 on the distal end side can be reduced, so even if there is variation in the amount of fixing material 1150 applied, the amount of variation in the fixing material 1150 in the groove 1125 on the distal end side will be reduced. Since it becomes smaller, the shift of the optical axis P can be suppressed.

FIG. 8 is a longitudinal cross-sectional view of the camera module 1000 in Comparative Example 2, which corresponds to the first embodiment shown in FIG. The principle of deviation in the optical axis P will be explained with reference to Comparative Example 2 shown in FIG. 8.
The depth of the groove 1125 is the same on the bottom side and the tip side of the holding member 1120. Even in this case, there is no variation in the amount of the fixing material 1150 applied, and the amount of the fixing material 1150 in the groove 1125 formed in the outer peripheral surface 1124 of one opposing side of the holding member 1120 is different from the amount of the fixing material 1150 applied on the other opposing outer peripheral surface 1124 of the holding member 1120. If the amount of fixing material 1150 in the groove 1125 formed in the surface 1124 is the same, no deviation of the optical axis P will occur.

In other words, if the fixing material 1150 of the same height and thickness penetrates into the grooves 1125 on the outer circumferential surface 1124 facing each other with the image sensor 1130 in between, even if the fixing material 1150 shrinks during curing, it will not harden. Since the moments due to the contraction forces are balanced, no deviation of the optical axis P occurs between the optical lens 1110 and the image sensor 1130.

However, during mass production, the amount of the fixing material 1150 that penetrates into the groove 1125 on the outer circumferential surface 1124 facing each other with the imaging device 1130 sandwiched therein varies due to variations in the amount of the fixing material 1150 applied and variations in the dimensions of the optical lens 1110 and the image sensor 1130. condition may occur.

As shown in FIG. 8, when the amount of fixing material 1150 in the groove 1125 is greater on one outer circumferential surface 1124 than on the other outer circumferential surface 1124, the curing shrinkage force Q1' on one outer circumferential surface 1124 is greater than that on the other outer circumferential surface. It becomes larger than the curing shrinkage force Q2' at 1124. As a result, the optical axis P shifts toward one outer circumferential surface 1124 and becomes the optical axis P', causing a shift in the optical axis P. In particular, when the amount of fixing material 1150 in the groove 1125 on the distal end side is large, the curing shrinkage force Q1' on the distal side becomes larger than the curing shrinkage force Q2' on the distal side, and the curing shrinkage force on the opposing outer circumferential surface 1124 increases. The moment due to balance causes a shift in the optical axis P of the optical lens 1110.

Even in such a case, in this embodiment, as described above, the amount of fixing material 1150 in the groove 1125 on the tip side can be reduced, so the amount of variation in the fixing material 1150 in the groove 1125 on the tip side is reduced. , the deviation of the optical axis P can be suppressed.

[Third embodiment]
The third embodiment will be described with reference to FIG.
In addition, matters described in the first and second embodiments but not described in this embodiment are also applied to this embodiment unless there are special circumstances.

FIG. 9 is a cross-sectional view of camera module 1000. This cross-sectional view is a cross-sectional view of the bottom side of the holding member 1120 in which the groove 1125 is formed.
As shown in FIG. 9, the groove 1125 is formed so that the width W2 on the bottom surface side of the groove 1125 is narrower than the width W1 on the opening side of the groove 1125.

It is generally known that the height of liquid suction due to capillary action increases as the width of groove 1125 is narrowed, but with a highly viscous liquid such as fixing material 1150 before hardening, if the width of groove 1125 is too narrow, the flow resistance due to shear force is large and capillary action does not occur. Therefore, for example, if the overall width of groove 1125 is narrowed, the amount of fixative 1150 penetrating into the interior of groove 1125 cannot be increased.

On the other hand, according to the present embodiment, the fixing material 1150 can be made to flow into the groove 1125 by widening the width W1 on the opening side of the groove 1125, and the width W2 on the bottom side of the groove 1125 can be narrowed. This can promote suction of the fixing material 1150 due to capillary action. Therefore, the suction force of the fixing material 1150 causes the fixing material 1150 to penetrate highly toward the distal end side within the groove 1125, so that the camera module 1000 can be made higher in strength and precision.
Note that this embodiment can be applied to the first embodiment and the second embodiment.

[Fourth embodiment]
A fourth embodiment will be described with reference to FIG. 10.
Note that matters described in the first to third embodiments but not described in this embodiment are also applied to this embodiment unless there are special circumstances.

FIG. 10 is a perspective view of the camera device 3000.
The camera device 3000 is configured by arranging two camera modules 1011 and 1022 side by side. The first camera module 1011 and the second camera module 1022 have the configurations described in the first to third embodiments, but when they are arranged side by side as the camera device 3000, camera modules having the same structure are used.

The first camera module 1011 and the second camera module 1022 are arranged side by side at a predetermined distance R, with their optical axes P1 and P2 approximately parallel to each other, and the housing 2001 is attached. The camera device 3000 measures the distance to the subject, for example, by comparing the image information acquired from the first camera module 1011 and the second camera module 1022.

Here, when the direction in which the first camera module 1011 and the second camera module 1022 are lined up is the base line length direction Of these, two outer circumferential surfaces 1124 are formed which are substantially parallel to the base line length direction and which are opposing outer circumferential surfaces 1124. Furthermore, in the second camera module 1022, the grooves 1125 are formed on two outer circumferential surfaces 1124 of the outer circumferential surface 1124 of the second camera module 1022 that are substantially parallel to the base line length direction and that are opposing outer circumferential surfaces 1124. It is formed.

That is, in the vehicle-mounted camera device 300, the first camera module 1011 and the second camera module 1022 are fixed to the housing 2001 with their optical axes substantially parallel to each other, and the first camera module 1011 and the second camera module 1022 are The holding member 1120 of the camera module 1022 has an outer peripheral surface 1124 that is approximately parallel to the base line length direction X along the direction in which the first camera module 1011 and the second camera module 1022 are lined up, 1124.

A method called parallax matching is generally used to calculate the distance to the subject based on the images obtained from the two camera modules 1011 and 1022. This is a distance measurement method based on the principle of triangulation, in which the parallax in the baseline length direction X of the two images is inversely proportional to the distance to the subject. In this method, the distance to the subject of tens of meters is converted into a parallax of several micrometers and detected, so in order to improve the distance measurement accuracy, it is important not to cause optical axis deviation, especially in the baseline length direction X. If the fixing material 1150 is present in the groove 1125, the optical axis deviation is likely to occur due to contraction during hardening of the fixing material 1150. In the vehicle-mounted camera device 300, the deviation in the baseline length direction X compared to the optical axes P1 and P2 of the first camera module 1011 and the second camera module 1022 has a greater adverse effect on performance, so the groove 1125 is provided only on the outer circumferential surface 1124 that is approximately parallel to the baseline length direction X, where the effect is small.

According to this embodiment, the possibility of optical axis deviation occurring is mainly due to optical axis deviation in the direction perpendicular to the base line length direction X, and optical axis deviation in the base line length direction X is less likely to occur. It is possible to suppress a decrease in distance measurement accuracy due to

According to the embodiment described above, the following advantageous effects can be obtained.
(1) The camera module includes a holding member 1120 that holds an optical lens 1110 therein, a substrate 1140 on which an image sensor 1130 is disposed, and a fixing material 1150 containing a light curing agent that fixes the bottom side of the holding member 1120 to the substrate 1140, and a vertically long groove 1125 that runs from the bottom side of the holding member 1120 to the tip side is formed on an outer peripheral surface 1124 on the bottom side of the holding member 1120. This allows the positional relationship between the optical lens and the image sensor to be maintained with high precision while being fixed.

The present invention is not limited to the above-described embodiments, and other forms that are conceivable within the scope of the technical concept of the present invention are also included within the scope of the present invention, so long as they do not impair the characteristics of the present invention. In addition, the above-described embodiments may be combined to form a configuration.

1000, 1001, 1011, 1022... Camera module, 1110... Optical lens, 1120... Holding member, 1121... Bottom surface of holding member, 1130... Image pickup element, 1140... Substrate, 1150 ...Fixing material, 1124...Outer peripheral surface, 1125...Groove, 1150...Fixing material, 2000, 2001...Casing, 3000...Camera device, P, P1, P2... optical axis.

Claims (6)

a holding member that holds the optical lens inside;
A board on which an image sensor is arranged,
a fixing material containing a photocuring agent that fixes the bottom side of the holding member and the substrate;
forming a vertically elongated groove extending from the bottom side to the tip side of the holding member on the outer circumferential surface of the bottom side of the holding member ;
In the camera module, the fixing material coated on the inside of the holding member has a higher concentration of the photocuring agent than the fixing material coated on the outside of the holding member. The camera module according to claim 1,
In the camera module, the groove is open to the bottom surface side of the holding member and is elongated vertically along the optical axis direction of the optical lens. The camera module according to claim 1,
In the camera module, the groove is formed so that the depth of the groove on the tip side is shallower than the depth of the groove on the bottom side of the holding member. The camera module according to claim 3,
In the camera module, the groove is formed to have a narrower width on the bottom surface side than the width on the opening side of the groove. The camera module according to claim 1,
The fixing material is a camera module containing a photocuring agent and a thermosetting agent. 6. An in-vehicle camera device comprising two camera modules according to claim 1 arranged side by side,
An in-vehicle camera device in which each of the camera modules is fixed to a housing with its optical axes approximately parallel to each other, the holding member of each of the camera modules has an outer peripheral surface that is approximately parallel to a baseline length direction along the direction in which each of the camera modules is arranged, and the groove is formed on the outer peripheral surface.

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