Patent Publication Number: US-2017361539-A1

Title: Image pickup module and the manufacturing method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Taiwan application serial no. 105118697, filed on Jun. 15, 2016. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     FIELD OF THE INVENTION 
     The invention relates to an image pickup module and a manufacturing method thereof. More particularly, the invention relates to an image pickup module including a plurality of image pickup units and a manufacturing method of the image pickup module. 
     DESCRIPTION OF RELATED ART 
     With the progress of science and technology, more and more electronic products are characterized by multiple functions, compact size, and high precision. In our daily lives, photo-taking functions of the electronic apparatus (e.g., an image pickup system, a handheld apparatus, or a medical investigation apparatus) are indispensable. In order to achieve favorable image quality and effects as well as provide extensive photo-taking functions, the electronic products may be equipped with an image pickup module with a plurality of image pickup units. 
     Nevertheless, according to the related art, in order to install the image pickup module with the image pickup units into the electronic apparatus, the image pickup units often need be assembled first. Here, the image pickup units are assembled into a fixing case to form an image pickup module, and an additional gel-filling space is required in the peripheries of the image pickup units, so as to fix the image pickup units into the fixing case through introducing adhesives into the space. In the fixing case, the accommodation space required for placing the image pickup units and the gel-filling space reserved for the adhesives lead to the unlikelihood of reducing the volume of the entire image pickup module. 
     SUMMARY OF THE INVENTION 
     The invention is directed to an image pickup module with a reduced volume. 
     The invention is also directed to a manufacturing method of an image pickup module which can be applied to manufacture the image pickup module with a reduced volume. 
     In an embodiment of the invention, an image pickup module that includes a cover, a plurality of image pickup units, a self-curing gel, and a photopolymer gel is provided. The cover includes an upper shield, a side shield connected to the upper shield, a plurality of illumination openings, and a plurality of image pickup openings. The illumination openings and the image pickup openings are formed on the upper shield, and the side shield surrounds the upper shield and form an accommodation space. The image pickup units are disposed in the accommodation space. Each of the image pickup units includes an upper surface, and the cover at least covers a portion of the upper surfaces of the image pickup units. Each of the image pickup units is configured to captures external images through one of the image pickup openings. The photopolymer gel is arranged on the upper surfaces of the image pickup units and disposed at positions corresponding to the illumination openings, and the illumination openings expose the photopolymer gel. The self-curing gel is disposed between the upper surfaces of the image pickup units and the upper shield. Each of the image pickup units is adhered to the cover through the photopolymer gel and the self-curing gel. The photopolymer gel is configured to fix relative positions between the image pickup units and the cover. 
     In an embodiment of the invention, a manufacturing method of an image pickup module includes: providing a cover that includes an upper shield, a plurality of illumination openings, and a plurality of image pickup opening; coating an upper surface of each of a plurality of image pickup units with an photopolymer gel and a self-curing gel, wherein the photopolymer gel is coated onto positions corresponding to the illumination openings of the cover; covering the image pickup units by the cover, wherein the upper shield of the cover covers the self-curing gel on the image pickup units, and the illumination openings expose the photopolymer gel on the image pickup units, such that the image pickup units capture external images through the image pickup openings; adjusting positions and angles of the image pickup units in the cover; curing the photopolymer gel and further fixing positions of the image pickup units before the positions of the image pickup units are fixed by the self-curing gel; curing the self-curing gel and further fixing positions the image pickup units into the cover. 
     According to an embodiment of the invention, a distribution area of the self-curing gel in each of the image pickup units is covered by the cover, and a space between the upper shield and the upper surface of each of the image pickup units is filled with the self-curing gel. 
     According to an embodiment of the invention, each of the upper surfaces of the image pickup units is rectangular, a distribution area of the photopolymer gel is adjacent to a corner of each of the upper surfaces, and a shape of the accommodation space surrounded by the cover is substantially a rectangular cube. 
     According to an embodiment of the invention, each of the image pickup units further includes a circuit board. 
     According to an embodiment of the invention, the self-curing gel is suitable for being cured at a curing temperature or a normal temperature. 
     According to an embodiment of the invention, the step of curing the photopolymer gel further includes irradiating the photopolymer gel by a curing light to cure the photopolymer gel. 
     According to an embodiment of the invention, the curing light is an ultraviolet light. 
     According to an embodiment of the invention, the image pickup units are connected to a circuit board. 
     According to an embodiment of the invention, a space between the side shield of the cover and side surfaces of the image pickup units is too small to be filled with the photopolymer gel or the self-curing gel. 
     In view of the above, the cover of the image pickup module provided herein is suitable for accommodating the image pickup units, and the image pickup units are fixed into the cover by the self-curing gel and the photopolymer gel. The photopolymer gel is able to fix the positions of the image pickup units before the positions of the image pickup units are fixed by the self-curing gel. As such, the image pickup units can be well affixed into the cover to form the image pickup module. By contrast, the self-curing gel can be pre-coated onto the surfaces of the image pickup units, and thus it is not required for the cover to reserve any space where the self-curing gel can be introduced. As a result, the overall volume of the image pickup module is reduced. 
     Several exemplary embodiments accompanied with figures are described in detail below to further describe the disclosure in details. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments and, together with the description, serve to explain the principles of the invention. 
         FIG. 1  is a schematic three-dimensional diagram illustrating an image pickup module according to a first embodiment of the invention. 
         FIG. 2A  to  FIG. 2F  are schematic diagrams illustrating each step in a manufacturing method of the image pickup module according to the first embodiment of the invention. 
         FIG. 3  is a back of a cover of an image pickup module according to the first embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS 
       FIG. 1  is a schematic three-dimensional diagram illustrating an image pickup module according to a first embodiment of the invention. With reference to  FIG. 1 , in the first embodiment of the invention, the image pickup module  100  includes an image pickup unit  110 , an image pickup unit  120 , and a cover  170 . The cover  170  includes an upper shield  176 , a side shield  178 , a plurality of illumination openings  172 , and image pickup openings  174 A and  174 B. The side shield  178  is connected to the upper shield  176 , and the side shield  178  surrounds the upper shield  176  and forms an accommodation space. The image pickup units  110  and  120  are arranged in the accommodation space, and the cover  170  covers sides of the image pickup units  110  and  120  configured to capture external images. Here, the upper shield  176  covers an upper surface of the image pickup unit  110  and an upper surface of the image pickup unit  120 , and the image pickup openings  174 A and  174 B are formed on the upper shield  176  of the cover  170 . Hence, the image pickup unit  110  can capture external images through the image pickup opening  174 A, and the image pickup unit  120  can capture external images through the image pickup opening  174 B. 
     In the present embodiment, the image pickup module  100  may further include a photopolymer gel  152  and a photopolymer gel  162 . The illumination openings  172  of the cover  170  are formed on the upper shield  176  of the cover  170 , and the photopolymer gel  152  and the photopolymer gel  162  are arranged on the upper surfaces of the image pickup units  110  and  120  and disposed on positions corresponding to the illumination openings  172 . Hence, the illumination openings  172  expose the photopolymer gel  152  and the photopolymer gel  162  on the image pickup units  110  and  120 . 
     In the present embodiment, the image pickup module  100  may further include a self-curing gel (not shown in  FIG. 1 ). The self-curing gel is arranged on the upper shield  176  covering a portion of the upper surfaces of the image pickup units  110  and  120 ; hence, the self-curing gel can, between the image pickup units  110  and  120  and the upper shield  176 , adhere the image pickup units  110  and  120  to the cover  170 . 
     In the present embodiment, the photopolymer gel  152  fixes the relative position between the image pickup unit  110  and the cover  170 , and the photopolymer gel  152  fixes the relative position between the image pickup unit  120  and the cover  170 . The self-curing gel adheres the cover  170  and the image pickup units  110  and  120  (which are fixed by the photopolymer gel  152  and the photopolymer gel  162 ) and is then cured. That is, the photopolymer gel  152  and the photopolymer gel  162  can adhere the upper surfaces of the image pickup units  110  and  120  to a portion of the upper shield  176  around the illumination openings  172 ; hence, before the self-curing gel is cured, the photopolymer gel  152  and the photopolymer gel  162  can fix the relative positions between the cover  170  and the image pickup units  110  and  120 . 
     According to the present embodiment, the cover  170 , the photopolymer gel  152 , the photopolymer gel  162 , and the self-curing gel are adopted by the image pickup module  100  to fix the image pickup units  110  and  120 ; therefore, the photopolymer gel  152  and the photopolymer gel  162  may temporarily fix the image pickup units  110  and  120  in the cover  170 . The relative positions of the image pickup units  110  and  120  and the cover  170  are maintained by the photopolymer gel  152  and the photopolymer gel  162 , and the self-curing gel is then cured to well fix the image pickup units  110  and  120  into the cover  170 . 
     To be specific, a material of the photopolymer gel  152  and the photopolymer gel  162  includes photopolymer resin, for instance, and a material of the self-curing gel includes thermosetting resin. Hence, the photopolymer gel  152  and the photopolymer gel  162  irradiated by light beams with specific wavelength can provide the temporary fixing function before the self-curing gel is cured, which should however not be construed as a limitation to the invention. In other embodiments of the invention, the photopolymer gel and the self-curing gel can both be made of resin that which can be directly cured, and the speed of curing the photopolymer gel is faster than the speed of curing the self-curing gel. Hence, the photopolymer gel can perform the temporary fixing function before the self-curing gel is cured. 
     Since the photopolymer gel  152 , the photopolymer gel  162 , and the self-curing gel achieve favorable adhesion effects between the upper shield  176  of the cover  170  and the upper surfaces of the image pickup units  110  and  120 , it is not required to provide a gel-filling space between the side shield  178  of the cover  170  and the image pickup units  110  and  120 , and the overall volume of the image pickup module  100  can be reduced. Particularly, the space between the side shield  178  of the cover  170  and side surfaces of the image pickup units  110  and  120  is too small to be filled with the photopolymer gel  152  and  162  or the self-curing gel. 
     In the present embodiment, the image pickup unit  110  includes a circuit board  181 , and the image pickup unit  120  includes a circuit board  182 , such that the image pickup units  110  and  120  can be electrically connected to external devices; however, the invention is not limited thereto. In another embodiment of the invention, the image pickup units  110  and  120  can be electrically connected to the same circuit board, such that the image pickup module  100  can be electrically connected to external devices more easily. 
     The manufacturing method of the image pickup module  100  and correlations among the components are explained below with reference to the attached drawings.  FIG. 2A  to  FIG. 2F  are schematic diagrams illustrating each step in a manufacturing method of the image pickup module  100  according to the first embodiment of the invention. With reference to  FIG. 2A , in the manufacturing method of the image pickup module  100  provided in the first embodiment of the invention, the image pickup units  110  and  120  are provided. The image pickup units  110  and  120  are, for instance, configured to take pictures or videos along approximately the same side. Particularly, the image pickup unit  110  includes an upper surface  111  and a side surface  113  connected to the upper surface  111 , the image pickup unit  120  includes an upper surface  121  and a side surface  123  connected to the upper surface  121 , and the upper surface  111  of the image pickup unit  110  and the upper surface  121  of the image pickup unit  120  face approximately the same side. External image beams enter the image pickup units  110  and  120  through the upper surfaces  111  and  121 . 
     With reference to  FIG. 2B , according to the manufacturing method of the image pickup module, the photopolymer gel  150  and the self-curing gel  130  are arranged on the image pickup unit  110 , and the photopolymer gel  160  and the self-curing gel  140  are arranged on the image pickup unit  120 . The self-curing gel  130  and the self-curing gel  140  are made of thermosetting resin, e.g., epoxy resin, and the photopolymer gel  150  and the photopolymer gel  160  are, for instance, made of an UV-cured adhesive, which should however not be construed as limitations to the invention. 
     Specifically, in the image pickup module  100  provided herein, the image pickup unit further includes image pickup lenses  112  and  122 ; in the image pickup unit  110 , a distribution area B 1  of the self-curing gel  130  surrounds the image pickup lens  112 , and a distribution area B 2  of the self-curing gel  140  surrounds the image pickup lens  122 . In the image pickup units  110  and  120 , a distribution area A 1  of the photopolymer gel  150  is different from and smaller than the distribution area of the self-curing gel  130 , and a distribution area A 2  of the photopolymer gel  160  is different from and smaller than the distribution area of the self-curing gel  140 . 
     In another aspect, as shown in  FIG. 2A , the shape of the image pickup units  110  and  120  and the shape of the upper surfaces  111  and  121  are rectangular, the distribution area of the photopolymer gel  150  is adjacent to a corner of the upper surface  111  of the image pickup unit  110 , the distribution area of the photopolymer gel  160  is adjacent to a corner of the upper surface  121  of the image pickup unit  120 , the distribution area of the self-curing gel  130  is adjacent to the peripheries of the upper surface  111 , and the distribution area of the self-curing gel  140  is adjacent to the peripheries of the upper surface  121 . Hence, the photopolymer gel  150 , the photopolymer gel  160 , the self-curing gel  130 , and the self-curing gel  140  well cover the upper surfaces  111  and  121  of the image pickup units  110  and  120 . 
     With reference to  FIG. 2C , according to the manufacturing method of the image pickup module, after the self-curing gel  130 , the self-curing gel  140 , the photopolymer gel  150 , and the photopolymer gel  160  are arranged, the image pickup units  110  and  120  are covered by the cover  170 . The cover  170  covers the self-curing gel  130  on the image pickup unit  110  and the self-curing gel  140  on the image pickup unit  120 . Besides, the photopolymer gel  150  on the image pickup unit  110  is exposed by the illumination opening  172  of the cover  170 , the photopolymer gel  160  on the image pickup unit  120  is exposed by the illumination opening  172  of the cover  170 , the image pickup unit  110  is exposed by the image pickup opening  174 A, and the image pickup unit  120  is exposed by the image pickup opening  174 B. That is, the cover  170  covers one portion of the upper surfaces  111  and  121  of the image pickup units  110  and  120 , and the covered portion of the upper surfaces  111  and  121  of the image pickup units  110  and  120  is coated with the self-curing gel  130  and the self-curing gel  140 . The cover  170  also exposes the photopolymer gel  150  and the photopolymer gel  160  on the other portion of the upper surfaces  111  and  121  of the image pickup units  110  and  120 , such that the photopolymer gel  150  and the photopolymer gel  160  on the image pickup units  110  and  120  can be directly exposed to external light beams or air. 
       FIG. 2D  is a schematic cross-sectional view taken along a section line I 1 I 1  in  FIG. 2C . To be specific, when the cover  170  provided in the present embodiment is arranged on the image pickup units  110  and  120 , the distribution area of the self-curing gel  130  and the self-curing gel  140  is covered by the cover  170 , such that the space between the upper shield  176  and the upper surface  111  of the image pickup unit  110  is filled with self-curing gel  130 , and that the space between the upper shield  176  and the upper surface  121  of the image pickup unit  120  is filled with self-curing gel  140 . A gel layer made of the self-curing gel  130  can be formed between the image pickup unit  110  and the upper shield  176 , such that one portion of the surface of the image pickup unit  110  can be connected to one portion of the inner surface of the upper shield  176  through the self-curing gel  130 . At the same time, a gel layer made of the self-curing gel  140  can be formed between the image pickup unit  120  and the upper shield  176 , such that one portion of the surface of the image pickup unit  120  can be connected to one portion of the inner surface of the upper shield  176  through the self-curing gel  140 . 
       FIG. 2E  is a schematic cross-sectional view taken along a section line  1212  in  FIG. 2C . In particular, when the cover  170  provided herein is disposed on the image pickup units  110  and  120 , a gel layer made of the photopolymer gel  150  can be formed between the image pickup unit  110  and the cover  170 , such that the other portion of the surface of the image pickup unit  110  can be connected to the other portion of the inner surface of the cover  170  adjacent to the illumination opening  172  through the photopolymer gel  150 . At the same time, a gel layer made of the photopolymer gel  160  can be formed between the image pickup unit  120  and the cover  170 , such that the other portion of the surface of the image pickup unit  120  can be connected to the other portion of the inner surface of the cover  170  adjacent to the illumination opening  172  through the photopolymer gel  160 . 
     As provided above, when the cover  170  covers the image pickup units  110  and  120 , all of the photopolymer gel  150 , the photopolymer gel  160 , the self-curing gel  130 , and the self-curing gel  140  are not yet cured, and therefore relative positions between the image pickup units  110  and  120  and the cover  170  can be adjusted. 
     In another embodiment of the invention, the relative positions and angles between the image pickup units  110  and  120  can be fixed in advance by using a fixture, and the photopolymer gel  150 , the photopolymer gel  160 , the self-curing gel  130 , and the self-curing gel  140  are then coated onto the image pickup units  110  and  120 . Therefore, when the cover  170  covers the image pickup units  110  and  120 , the relative positions and angles between the image pickup units  110  and  120  can be properly maintained. 
     With reference to  FIG. 2F , in the manufacturing method of the image pickup module provided herein, after the image pickup units  110  and  120  are arranged in the cover  170 , the photopolymer gel  150  and  160  are cured to form the photopolymer gel  152  and the photopolymer gel  162 , and the positions of the image pickup units  110  and  120  are fixed before the positions of the image pickup units  110  and  120  are fixed by the self-curing gel  130  and the self-curing gel  140 . That is, the cured photopolymer gel  152  and the cured photopolymer gel  162  can temporarily fix the positions of the image pickup units  110  and  120  in the cover  170 , and the positions of the image pickup units  110  and  120  in the cover  170  can be further adjusted through performing said step, such that the image pickup units  110  and  120  can be properly positioned in the cover  170 . As a result, through applying the manufacturing method provided in the present embodiment, the image pickup module  100  with favorable performance can be formed after the self-curing gel  130  and the self-curing gel  140  are cured in the cover  170 . 
     Particularly, in the present embodiment, a curing light L is applied to cure the photopolymer gel  150  and the photopolymer gel  160 , so as to form the photopolymer gel  152  and the photopolymer gel  162 . Here, the photopolymer gel  150  and the photopolymer gel  160  are UV-cured adhesives, for instance, and the curing light L is an ultraviolet light, for instance. The material of the self-curing gel  130  and the self-curing gel  140  includes thermosetting resin, e.g., epoxy resin, and the self-curing gel  130  and the self-curing gel  140  are suitable for being cured at a normal temperature or at a curing temperature higher than the normal temperature, which should however not be construed as limitations to the invention. Specifically, to complete the manufacture of the image pickup module  100 , the self-curing gel  130  and the self-curing gel  140  can be fixed by performing a low-temperature baking with use of an oven. 
     According to the manufacturing method of the image pickup module  100  provided in the present embodiment, the self-curing gel  130 , the self-curing gel  140 , the photopolymer gel  150 , and the photopolymer gel  160  are disposed on the image pickup units  112  and  120 , and the image pickup units  112  and  120  are arranged in the cover  170 . Here, the illumination openings  172  of the cover  17  expose the photopolymer gel  150  and the photopolymer gel  160 . Hence, it is not necessary for the cover  170  to have any opening through which the gel is introduced or any space for the gel to flow, and thus the overall volume of the image pickup module  100  can be significantly reduced. Besides, the self-curing gel  130  and the self-curing gel  140  are coated onto the image pickup units  110  and  120  in advance; hence, the self-curing gel  130  and the self-curing gel  140  can be precisely arranged on the surfaces of the image pickup units  110  and  120  and do not overflow. Thereby, the manufacturing yield of the resultant image pickup module  100  can be improved. 
     In the present embodiment, the cover  170  further includes a light incident surface  171 , and the illumination openings  172  penetrate the light incident surface  171 . A projection area of the illumination openings  172  along a normal direction of the light incident surface  171  is located within the distribution area of the upper surfaces  111  and  121  of one of the image pickup units  110  and  120 . Namely, the illumination openings  172  are configured to expose the photopolymer gel  150  and the photopolymer gel  160  on one portion of the upper surfaces of one of the image pickup units  110  and  120 , such that the photopolymer gel  150  and the photopolymer gel  160  on the areas A 1  and A 2  can be irradiated by external light beams. 
     Besides, the image pickup openings  174 A and  174 B penetrate the light incident surface  171 . The image pickup unit  110  captures an external image through the image pickup opening  174 A, and the image pickup unit  120  captures an external image through the image pickup opening  174 B. 
       FIG. 3  is a back view of a cover of an image pickup module according to the first embodiment of the invention. With reference to  FIG. 2F  and  FIG. 3 , in the present embodiment, the side shield  178  of the cover  170  is configured to surround the image pickup units  110  and  120 , the illumination openings  172  are formed on the upper shield  176 , and an inner surface  173  of the cover  170  is configured to connect the image pickup units  110  and  120  through the self-curing gel  130 , the self-curing gel  140 , the photopolymer gel  150 , and the photopolymer gel  160 . In other words, the side shield  178  and the upper shield  176  of the cover  170  define an accommodation space where the image pickup units  110  and  120  are located. Note that the accommodation space is surrounded by the side shield  178  and the upper shield  176 . As such, the image pickup units  110  and  120  can be well fixed in the cover  170 , so as to manufacture the image pickup module  100  with good quality and small volume. 
     With reference to  FIG. 3 , in the present embodiment, a shape of the accommodation space surrounded by the cover  170  is substantially a rectangular cub, and the volume of the accommodation space approximates to the total volume of the image pickup units  110  and  120 ; hence, the volume of the image pickup module  100  can be significantly reduced. To be specific, the material of the cover  170  provided herein includes plastic, for instance; however, the invention is not limited thereto. In other embodiments of the invention, the material of the cover may further include metal or non-metal. 
     To sum up, the cover of the image pickup module provided herein is suitable for accommodating the image pickup units, and the cover expose the photopolymer gel on the image pickup units; hence, the image pickup units can be temporarily fixed into the cover by the photopolymer gel, and the photopolymer gel is able to fix the positions of the image pickup units before the positions of the image pickup units are fixed by the self-curing gel. In addition, the area where the photopolymer gel and the self-curing gel are coated is not limited by the size of the openings of the cover, and therefore the image units can be well affixed into the cover to form the image pickup module. In addition, according to the manufacturing method of the image pickup module provided herein, the self-curing gel can be pre-coated onto the surfaces of the image pickup units, and thus it is not required for the cover to reserve any space for introducing the self-curing gel and allowing the self-curing gel to flow. As a result, the overall volume of the image pickup module is reduced. 
     Although the disclosure has been provided with reference to the above embodiments, it will be apparent to one of ordinary skill in the art that modifications to the described embodiments may be made without departing from the spirit of the disclosure. Accordingly, the scope of the disclosure will be defined by the attached claims and not by the above detailed descriptions.