JP2010237319A - Plastic lens, plastic lens wafer, molding die, plastic lens unit, image capturing apparatus, electronic device, and method of manufacturing plastic lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plastic lens, having high performance and high reliability, which suppresses curvature due to a setting shrinkage of an optical resin for the lens and curvature due to a difference in coefficient of linear expansion between a lens material made of the optical resin and a frame material for a lens substrate etc., when manufactured such that the optical resin is extended on the backside of the lens substrate, and to provide a plastic lens wafer, a molding die, a plastic lens unit, an image capturing apparatus, electronic device, and a method of manufacturing the plastic lens. <P>SOLUTION: The plastic lens 10 has the lens substrate 2 having a first through-hole 1 and a lens effective diameter portion 3 made of the optical resin. The first through-hole 1 is filled with the optical resin. The optical resin is extended to cover a lens substrate backside 2a, and a dug portion 6 filled with the optical resin is formed at a periphery of the first through-hole on a lens substrate surface 2b. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a plastic lens, a plastic lens wafer, a molding die, a plastic lens unit, an imaging device, an electronic device, and a method for manufacturing a plastic lens, and more specifically, an optical resin for a lens on the back surface of a lens substrate. Suppresses warpage due to curing shrinkage of optical resin and warpage due to difference in linear expansion coefficient between lens material molded by optical resin and frame material such as lens substrate, etc. It relates to plastic lenses.

  Generally, a camera module includes a lens and an image sensor that recognizes light imaged by the lens and converts it into an image signal. The accuracy of the image signal is greatly influenced by the relative positional accuracy between the lens and the image sensor. For this reason, high positional accuracy is required for alignment between the lens and the image sensor.

  However, since the relative positional accuracy between the lens and the image sensor depends on many factors, it is difficult to perform uniform alignment in each camera module.

  Therefore, after manufacturing the camera module, it is necessary to detect a relative position shift between the lens and the image sensor and correct the relative position for each camera module.

  Such a process of correcting the relative position of each camera module increases the number of manufacturing steps of the camera module and further increases the manufacturing cost.

  In order to solve the above problem, for example, in Patent Document 1, as shown in FIG. 12, a lens 102 is assembled to a light shielding lens frame 101 that is a light shielding member by insert molding, and the light shielding lens frame 101 and the lens are assembled. A plastic lens 100 integrated with 102 is disclosed.

  In the plastic lens 100, since the centering of the center of the light shielding lens frame 101 and the optical axis of the lens 102 is realized with extremely high accuracy, the manufacturing cost is reduced.

  For example, Patent Document 2 discloses a method of manufacturing a camera device 201 on a wafer scale as shown in FIGS. 13 (a) and 13 (b). FIG. 13A is a cross-sectional view showing the configuration of the camera device 201, and FIG. 13B is a perspective view showing the substrate stack 200 before the individual camera devices 201 are cut. In Patent Document 2, by manufacturing camera devices 201 on a wafer scale, a process of mass-producing camera devices 201 at a time can be realized.

JP 2005-84328 A (published March 31, 2005) JP 2005-539276 A (published on December 22, 2005)

  However, since the plastic lens 100 disclosed in the above-mentioned conventional patent document 1 is filled with resin mainly in one direction of the light shielding lens frame 101 and cured as shown in FIG. 12, the light shielding lens is caused by curing shrinkage of the resin. The warp of the frame 101 occurs. That is, since the amount of filled resin differs between the upper and lower sides of the light shielding lens frame 101, warpage of the light shielding lens frame 101 occurs due to curing shrinkage of the resin.

  Further, when the optical resin for molding the lens 102 is a thermosetting resin, the linear expansion difference between the light shielding lens frame 101 and the optical resin for molding the lens 102 when the temperature is lowered to room temperature after molding at a high temperature. The thermal distortion resulting from this occurs. Furthermore, if the optical resin for molding the lens 102 and the light-shielding lens frame 101 are materials having heat resistance of 250 ° C. or higher, a solder reflow process can be performed, but thermal distortion also occurs in this process. These thermal distortions appear as warping or deformation of the plastic lens 100, and affect the surface accuracy of the plastic lens 100, so that a highly accurate lens shape cannot be obtained.

  Next, in Patent Document 2, as shown in FIG. 13A, the lenses 211 and 221 are located only in the vicinity of the through holes, and the plurality of lenses 211 and 221 are independent of the lens substrates 210 and 220, respectively. . At this time, if the rigidity of the lens substrates 210 and 220 is small, warping of the lens substrates 210 and 220 occurs due to curing shrinkage of the lens. Further, when the difference in linear expansion coefficient between the lens 211 and the lens substrate 210 and between the lens 221 and the lens substrate 220 is large, warping appears remarkably in the thermosetting resin molding step and the reflow process.

  Even if the warpage caused by the curing shrinkage of the lens resin or the linear expansion coefficient difference between the lens 211 and the lens substrate 210 and between the lens 221 and the lens substrate 220 is very small when viewed from the respective lenses 211 and 221, the lens. It becomes very large when viewed from the whole wafer. As the wafer size increases, the amount of warpage increases in a quadratic function, so that the lens wafer cannot be attached with high accuracy, and a highly accurate camera module cannot be manufactured. In addition, there is a problem that the yield decreases.

  Further, as described above, since the lenses 211 and 221 are independent from the lens substrates 210 and 220, respectively, it is necessary to individually fill the lenses 211 and 221 with a lens resin when molding the lens portion. There is a problem that productivity is poor. At this time, if the lens resin is extended to at least one of the lens substrates 210 and 220 and the lenses 211 and 221 are formed in a form in which the frame is inserted, there is no need to individually fill the lens resin, and productivity is improved. improves.

  However, when the lens resin is extended only on one surface of the lens substrates 210 and 220, there is a problem that the wafer is significantly warped due to the contraction of the extended resin.

  On the other hand, if the lens resin can be extended on both surfaces of the lens substrates 210 and 220, the moment generated by the contraction of the lens resin is balanced between the upper and lower surfaces. Therefore, the lens resin is extended only on one surface. The warpage can be reduced more than the case.

  However, when insert molding of the lens part is actually performed, since either one of the surfaces is in contact with the mold, it is practically difficult to extend the lens resin on both surfaces of the lens substrates 210 and 220. Further, when the lens resin is extended on both sides, there arises a problem that the lens thickness increases.

  The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to cure and shrink optical resin when the optical resin for lenses extends on the back surface of the lens substrate. A plastic lens, a plastic lens wafer, and a high-performance and high-reliability plastic lens that suppresses the warpage caused by the difference in linear expansion coefficient between the lens material molded by the optical resin and the frame material such as the lens substrate, An object of the present invention is to provide a molding die, a plastic lens unit, an imaging device, an electronic device, and a method for manufacturing a plastic lens.

  In order to solve the above problems, the plastic lens of the present invention is a plastic lens having a lens substrate having a first through hole and a lens made of an optical resin, and the first through hole has an optical resin. And the optical resin extends so as to cover the back surface of the lens substrate, and the periphery of the first through-hole on the surface of the lens substrate is filled with the optical resin. It is characterized in that a recessed portion is formed.

  According to the above invention, the first through hole is filled with the optical resin, and the optical resin extends so as to cover the back surface of the lens substrate. For this reason, in this state, due to the difference in the amount of optical resin on the front and back surfaces of the lens substrate due to the optical resin extending on the back surface of the lens substrate, the lens substrate is warped due to curing shrinkage of the optical resin. At the same time, warping occurs due to differences in linear expansion coefficients between the optical resin and the lens substrate when the temperature is lowered to room temperature after molding at a high temperature.

  Therefore, in the present invention, a digging portion is formed around the first through hole on the surface of the lens substrate, and the digging portion is filled with an optical resin.

  As a result, since the optical resin is provided on the front and back surfaces of the lens substrate, the curing shrinkage rate of the optical resin on the front and back surfaces of the lens substrate and the shrinkage rate based on the difference in linear expansion coefficient are substantially equal.

  Therefore, when the optical resin for the lens is manufactured so as to extend on the back surface of the lens substrate, the warp due to the curing shrinkage of the optical resin, and the lens material molded by the optical resin and the frame material such as the lens substrate The plastic lens which suppressed the curvature resulting from a linear expansion coefficient difference with this, and provided high performance and high reliability can be provided.

  In the plastic lens of the present invention, the digging portion of the lens substrate is provided with a second through hole penetrating the lens substrate, and the digging portion is filled in the second through hole. It is preferable that an optical resin for connecting the optical resin and the optical resin extending so as to cover the back surface of the lens substrate is filled.

  Accordingly, a second through hole penetrating the lens substrate is provided in the digging portion of the lens substrate. For this reason, when performing insert molding, if the first mold is set on the surface of the lens substrate, the engraved portion is filled with the optical resin through the second through hole from the back surface side of the lens substrate, The optical resin of the digging portion can be molded.

  This eliminates the need for a process of separately filling the digging portion with the optical resin from the surface side of the lens substrate, thereby simplifying the production process.

  In the plastic lens of the present invention, a groove connecting the digging portion and the first through hole is formed on the surface of the lens substrate, and the digging portion is filled in the groove. It can be assumed that an optical resin that communicates the optical resin thus formed and the optical resin formed in the first through hole of the lens substrate is filled.

  As a result, when the optical resin is insert-molded into the lens substrate, the optical resin can be obtained by filling the first through hole with the optical resin simply by contacting the first mold on the surface side of the lens substrate. The resin flows through the groove to the digging part. For this reason, the digging portion can be filled with the optical resin and molded.

  Therefore, a process for filling the digging portion with a separate resin is not necessary, and the production process is simplified. For example, since it is not necessary to provide the above-described second through hole in the lens substrate, the lens substrate can be manufactured simply and inexpensively.

  In the plastic lens of the present invention, it is preferable that a protrusion is formed on at least the back surface of the lens substrate.

  Thereby, when there are a plurality of plastic lenses, the protrusions can be used as spacers when the plastic lenses are stacked.

  Therefore, it is possible to provide a method for manufacturing a lens at low cost without requiring a step of manufacturing a spacer and a step of adjusting the stress position of the spacer.

  In addition, since a rib structure is not required, a highly accurate and highly reliable lens module can be provided without considering the generation of internal stress.

  In the plastic lens of the present invention, it is preferable that the digging depth of the digging portion is ½ or less of the thickness of the lens substrate in the optical axis direction.

  Thereby, the curvature suppression effect of a plastic lens can be acquired, without impairing the rigidity of the frame material in a lens substrate remarkably.

  Further, problems such as short shots when a lens substrate that is a frame is manufactured by molding can be avoided. Furthermore, when a lens substrate made of a frame material is manufactured by machining, the thickness of the lens substrate is not significantly reduced, so that the chipping defect of the lens substrate due to processing can be reduced and productivity can be improved. it can.

  In order to solve the above problems, the plastic lens wafer of the present invention is characterized in that the plastic lenses described above are formed in an array.

  According to the above invention, the plastic lens wafer is formed with a plurality of plastic lenses provided with the first through holes and the digging portions in an array. That is, a plastic lens array can be obtained by collectively molding lenses on the lens substrate with an optical resin. After the plastic lens array, the diaphragm and the spacer are laminated and bonded, the plastic lens wafer is diced, and each plastic lens is separated into individual pieces, so that the plastic lens unit can be mass-produced at low cost.

  In addition, imaging devices represented by CMOS and CCD are laminated and bonded together with a plastic lens array, diaphragm and spacer at the wafer level, and then the plastic lens lens wafer is diced into individual pieces, thereby mass-producing imaging devices at low cost. can do.

  That is, conventionally, when a plastic lens array is laminated, the warp of the plastic lens wafer affects the alignment and inclination of the plastic lens wafers. However, in the present invention, the plastic lenses are arranged in an array. By using a wafer, a high-performance plastic lens unit or imaging device can be mass-produced at low cost.

  In order to solve the above problems, the molding die of the present invention is used for molding the plastic lens described above.

  According to said invention, the plastics lens which has the effect of this invention can be simply manufactured by insert molding by insert-installing a lens board | substrate previously to a shaping die. In addition, by using a molding die structure capable of obtaining a large number of plastic lenses, a method for mass production at low cost can be provided.

  In order to solve the above-mentioned problems, a plastic lens unit of the present invention is characterized by including the above-described plastic lens.

  According to the above invention, a high-performance plastic lens unit can be provided at low cost by a high-precision plastic lens and high-precision assembly.

  In order to solve the above-described problems, an imaging apparatus according to the present invention includes the above-described plastic lens unit.

  According to the above invention, a high-performance imaging device can be provided at a low cost by a high-precision plastic lens and a high-precision assembly.

  In order to solve the above-described problems, an electronic apparatus according to the present invention includes the above-described imaging device.

  According to the above invention, a high-performance electronic device can be provided at a low cost.

  In order to solve the above-described problem, the plastic lens manufacturing method of the present invention is arranged such that after placing the lens substrate inside the molding die described above, an optical resin is applied to the first through hole and the digging portion. It is characterized by molding.

  According to the above invention, when the lens resin is manufactured so as to extend on the back surface of the lens substrate, the warp due to the curing shrinkage of the lens resin, the lens material molded by the optical resin, the lens substrate, It is possible to provide a method for manufacturing a plastic lens that suppresses warping due to a difference in linear expansion coefficient from a material to be a frame and imparts high performance and high reliability by insert molding.

  As described above, in the plastic lens of the present invention, the first through hole is filled with the optical resin, and the optical resin extends so as to cover the back surface of the lens substrate. A digging portion filled with an optical resin is formed around the first through-hole on the surface.

  As described above, the plastic lens wafer of the present invention is one in which the plastic lenses described above are formed in an array.

  As described above, the molding die of the present invention is used for molding the plastic lens described above.

  As described above, the plastic lens unit of the present invention includes the plastic lens described above.

  As described above, the imaging apparatus of the present invention includes the plastic lens unit described above.

  As described above, an electronic apparatus according to the present invention includes the imaging device described above.

  As described above, the method for producing a plastic lens of the present invention is a method of molding an optical resin in the first through hole and the digging portion after disposing the lens substrate inside the molding die described above. It is.

  Therefore, when the optical resin for the lens is manufactured so as to extend on the back surface of the lens substrate, the warp due to the curing shrinkage of the optical resin, and the lens material and the lens substrate frame formed by the optical resin. Manufacture of plastic lenses, plastic lens wafers, molding dies, plastic lens units, imaging devices, electronic devices, and plastic lenses with high performance and high reliability by suppressing warping caused by differences in linear expansion coefficient with materials There is an effect of providing a method.

(A) shows one Embodiment of the plastic lens in this invention, Comprising: It is a top view which shows the structure of a plastic lens, (b) is sectional drawing which shows the structure of a plastic lens. (A) shows the modification of the said plastic lens, Comprising: It is a top view which shows the structure of the plastic lens which provided the runner, (b) is sectional drawing which shows the structure of the plastic lens which provided the runner. . (A) shows the other modification of the said plastic lens, Comprising: It is a top view which shows the structure of the plastic lens which provided the digging part continuously in the 1st through-hole, (b) is digging It is sectional drawing which shows the structure of the plastic lens which provided the insertion part continuously in the 1st through-hole. (A) is a plan view showing a configuration of a plastic lens provided with a projection, and shows another modification of the plastic lens, and (b) is a configuration of the plastic lens provided with a projection. It is sectional drawing shown. (A) is a perspective view which shows the structure of the plastic lens wafer which formed the said plastic lens in the shape of an array, (b) shows the structure of a plastic lens wafer, Comprising: AA of (a) FIG. It is sectional drawing which shows the structure before lamination | stacking in the case of laminating | stacking the said plastic lens wafer in multiple numbers. It is sectional drawing which shows the structure after lamination | stacking in the case of laminating | stacking the said plastic lens wafer in multiple numbers. It is sectional drawing which shows the structure of the imaging device which separated what laminated | stacked the said plastic lens wafer several pieces. It is sectional drawing which shows the structure of the molding die used when manufacturing a plastic lens. (A) shows the Example of a plastic lens wafer, Comprising: It is a perspective view which shows the structure of the surface of a plastic lens wafer, (b) is a perspective view which shows the structure of the back surface of a plastic lens wafer. (A) shows the Example of a plastic lens wafer, Comprising: It is a top view which shows the structure of a plastic lens wafer when there is no digging part, (b) is a plastic lens when a digging part exists It is a top view which shows the structure of a wafer. It is sectional drawing which shows the structure of the conventional plastic lens. (A) is sectional drawing which shows the structure of the conventional laminated plastic lens, (b) is an exploded perspective view which shows the structure of the conventional laminated plastic lens wafer.

  An embodiment of the present invention will be described below with reference to FIGS.

  The structure of the plastic lens of the present embodiment will be described below with reference to FIG. FIG. 1A is a plan view showing a plastic lens, and FIG. 1B is a plan view showing light passing through the center of the optical axis of the plastic lens and the midpoint of one side of the square shape in the lens ineffective diameter portion of the plastic lens. It is sectional drawing parallel to an axial direction.

  As shown in FIGS. 1A and 1B, the plastic lens 10 of the present embodiment has a lens substrate 2 having a first through-hole 1 and an effective lens diameter as a lens that forms an optical function with an optical resin. Part 3. The planar shape of the plastic lens 10 viewed from the optical axis direction is, for example, a square. However, the shape is not necessarily limited to this, and may be another polygon, a circle, or a similar shape.

  The lens effective diameter portion 3 is, for example, a convex meniscus lens whose upper surface is raised in a convex shape. However, the lens effective diameter portion 3 is not necessarily limited thereto, and may be a convex lens, a concave lens, a concave meniscus lens, or an aspherical lens.

  The outside of the lens effective diameter portion 3 is a lens non-effective diameter portion 4 constituted by the lens substrate 2. On the lens substrate back surface 2a, which is one surface of the lens substrate 2 constituting the lens non-effective diameter portion 4, an optical resin extending portion 5 formed by extending an optical resin is formed.

  In the present embodiment, the lens non-effective diameter portion 4 is provided with a digging portion 6 as a recess in the lens substrate surface 2b which is the other surface of the lens substrate 2 different from the lens substrate back surface 2a. The digging portion 6 is also filled with optical resin. 1A and 1B, the digging portion 6 is formed in a ring shape along the outer periphery of the lens effective diameter portion 3 while being separated from the optical resin of the lens effective diameter portion 3. .

  As described above, the plastic lens 10 of the present embodiment has the digging portion 6 filled with the optical resin. For this reason, when the plastic lens 10 is molded, the optical resin filled in the digging portion 6 contracts along with the contraction of the optical resin extending portion 5. That is, since the optical resin is provided on both the lens substrate back surface 2 a and the lens substrate surface 2 b of the lens substrate 2, the curing shrinkage rate and the linear expansion coefficient difference of the optical resin on the front and back surfaces of the lens substrate 2 can be reduced. The shrinkage rate based on it becomes substantially equal.

  Accordingly, when the lens substrate 2 is manufactured such that the lens optical resin extends on the lens substrate back surface 2a, warpage caused by the curing shrinkage of the optical resin, and the lens material and the lens substrate molded by the optical resin. It is possible to suppress warping caused by a difference in linear expansion coefficient from the material that forms the frame.

  In addition, it is possible to provide the plastic lens 10 that can perform alignment and bonding of the plastic lens 10 to the sensor module and alignment and bonding of the plastic lenses with high accuracy.

  Furthermore, by molding the optical resin so as to extend to the lens substrate back surface 2a, which is one side of the lens substrate 2, the thickness error of the lens substrate 2 can be corrected with the optical resin, and the thickness is highly accurate in the thickness direction. A plastic lens 10 can be provided.

  In addition, when the optical resin is formed on the lens substrate 2 by extending the optical resin on the lens substrate back surface 2a of the lens substrate 2, the lens substrate 2 comes into contact with the upper and lower molds at the same time. Therefore, the molding pressure of the mold can be efficiently transmitted to the optical resin. Thereby, a highly accurate lens shape can be obtained.

  Furthermore, if the lens substrate 2 is an opaque material, the light blocking functionality of the plastic lens 10 can be imparted.

  If the digging portion 6 is not connected to the lens effective diameter portion 3, the optical resin filled in the digging portion 6 when the digging portion 6 becomes an adhesive portion when the plastic lens 10 is overlaid. It is possible to prevent stray light and flare at the time of imaging caused by.

  Here, in the plastic lens 10, as shown in FIG. 1B, the digging portion 6 of the lens substrate 2 is provided with, for example, a second through hole 7 that penetrates the lens substrate 2. The optical resin for connecting the optical resin filled in the digging portion 6 and the optical resin of the optical resin extending portion 5 extending so as to cover the lens substrate back surface 2a to the second through hole 7. Can be filled. In addition, although the number of the 2nd through-holes 7 is required at least one, plural may be sufficient and the number does not ask | require.

  Thus, when insert molding is performed, if a lower mold 42 to be described later is set on the lens substrate surface 2b, the engraved portion 6 is filled with the optical resin through the second through hole 7 from the lens substrate back surface 2a side. Thus, the optical resin of the digging portion 6 can be molded.

  This eliminates the need for a process of separately filling the digging portion 6 with the optical resin from the lens substrate surface 2b side, thereby simplifying the production process.

  Further, since the digging portion 6 is not connected to the lens effective diameter portion 3, the optical resin filled in the digging portion 6 is obtained when the digging portion 6 becomes an adhesive portion when the plastic lens 10 is overlapped. It is possible to prevent stray light and flare at the time of imaging caused by.

  The depth of the digging portion 6 is preferably set to ½ or less of the thickness in the optical axis direction of the lens substrate 2 that is a frame material. Thereby, the curvature suppression effect of the plastic lens 10 can be acquired, without impairing the rigidity of the lens board | substrate 2 which is frame material remarkably. Moreover, problems such as short shots when the lens substrate 2 as a frame is manufactured by molding can be avoided. The short shot is a phenomenon in which a part of a molded product is missing and an incompletely shaped molded product is produced.

  Further, when the lens substrate 2 that is a frame is manufactured by machining, the thickness of the frame is not significantly reduced, so that the chipping defect of the frame due to the processing can be reduced and the productivity can be improved. . The chipping failure means that the chip is missing.

  Here, the plastic lens 10 of the present embodiment is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention.

  For example, in the above description, the optical resin of the first through hole 1 and the optical resin of the digging portion 6 are completely separated from each other, but the present invention is not particularly limited to this. For example, as shown in FIGS. 2 (a) and 2 (b), a runner 8 is formed on the lens substrate surface 2 b as a groove connecting the digging portion 6 and the first through hole 1. The optical resin filled in the digging portion 6 and the optical resin communicating with the optical resin formed in the first through hole 1 can be filled in advance.

  Thereby, when the optical resin is molded on the lens substrate 2, the optical resin of the digging portion 6 can be molded by passing the runner 8 and filling the digging portion 6 with the optical resin. As a result, a process for filling the digging portion 6 with a separate optical resin is not required, and the production process is simplified.

  Further, since it is not necessary to provide the second through hole 7 shown in FIG. 1B, the lens substrate 2 can be manufactured easily and inexpensively.

  On the other hand, the digging portion 6 may be a digging portion 16 in a form in contact with the lens effective diameter portion 3 as shown in FIGS. 3 (a) and 3 (b), for example. In this case, even the optical resin having a high viscosity can be filled in the dug portion 16 without causing a short shot.

  Further, in the present embodiment, as shown in FIGS. 4A and 4B, it is preferable to form a protrusion 9 on at least the lens substrate back surface 2a of the lens substrate 2.

  Thereby, when sticking together at least two plastic lenses 10, the projection 9 can be used as a spacer. As a result, it is possible to provide a method of manufacturing the plastic lens 10 at a low cost without requiring a step of manufacturing a spacer and a step of adjusting the stress position of the spacer.

  In addition, since a rib structure is not required, a highly accurate and highly reliable lens module can be provided without considering the generation of internal stress.

  Moreover, in this Embodiment, as shown to Fig.5 (a) (b), it is possible to form with the plastic lens wafer 20 which shape | molded the some plastic lens 10 in the array form. That is, the plastic lens wafer 20 is formed with a plurality of plastic lenses 10 each having the first through holes 1 and the dug portions 6 formed in an array.

  In this way, a plastic lens array can be obtained by collectively molding the lens effective diameter portion 3 as a lens on the lens substrate 2 with a thermosetting optical resin. Accordingly, as shown in FIGS. 6 to 8, after the plastic lens array, a diaphragm (not shown), and the spacer 21 are laminated and bonded, the plastic lens wafer 20 is diced, and each plastic lens 10 is separated into individual pieces. It is possible to mass-produce the plastic lens unit 31 composed of a plurality of laminated plastic lenses 10 at a low cost.

  Further, as shown in FIGS. 6 to 8, an image pickup device 22 represented by a CMOS (Complementary Metal Oxide Semiconductor) and a CCD (Charge Coupled Device) is arranged in a lens array at the wafer level. Then, after laminating and adhering together with a diaphragm (not shown) and the spacer 21, the imaging device 30 can be mass-produced at low cost by dicing the lens wafer into pieces by using a wire or a laser.

  As described above, when the lens arrays are stacked, the thermosetting optical resin is formed on the plastic lens wafer 20 with respect to the first through holes 1 of the plurality of lens substrates 2 arranged in parallel. As a result, the effective lens diameter portions 3 are molded, while the linear expansion coefficient of the thermosetting resin is larger than that of the lens substrate 2 which is a frame material. For this reason, the warp of the plastic lens wafer 20 affects the alignment and inclination of the plastic lens wafers 20.

  However, in the present embodiment, since the plastic lens wafer 20 in which the plastic lenses 10 are arranged in an array is used, this problem does not occur. As a result, the high-performance plastic lens unit 31 and the imaging device 30 are provided. It can be mass-produced at low cost.

  As described above, the plastic lens unit 31 of the present embodiment includes the plastic lens 10 of the present embodiment. Thus, the high-performance plastic lens unit 31 and the high-precision assembly can provide the high-performance plastic lens unit 31 at a low cost.

  Further, the imaging device 30 of the present embodiment includes the plastic lens unit 31 of the present embodiment. Thus, the high-performance imaging device 30 can be provided at low cost by the high-precision plastic lens 10 and the high-precision assembly.

  Furthermore, in the present embodiment, the imaging device 30 of the present embodiment can be mounted on an electronic device such as a camera or a video camera. Thereby, a high-performance electronic device can be provided at low cost.

  Here, a manufacturing method of the plastic lens 10 having the above configuration will be described.

  In the method of manufacturing the plastic lens 10 of the present embodiment, for example, as shown in FIG. 9, the lens substrate 2 shown in FIGS. 1 (a) and 1 (b) is turned upside down, and the upper mold 41 and the lower mold 42 are used. It mounts on the lower mold | type 42 of the shaping die 40 which becomes. That is, the lens substrate 2 is inserted. Next, the upper die 41 is lowered from the upper side, and the upper die 41 and the lower die 42 are brought into contact with each other. Then, an optical resin made of a thermosetting resin is injected from a resin injection port 41 a provided at the center of the upper mold 41.

  As a result, the optical resin is filled in the first through hole 1 and the optical resin extending portion 5, and the optical resin filled in the optical resin extending portion 5 is dug through the second through hole 7. Fill up to 6.

  Thereafter, when the temperature of the optical resin reaches normal temperature, the molding die 40 is released, and the completed plastic lens 10 is taken out.

  As described above, in the present embodiment, the plastic lens 10 having the effects of the present embodiment can be easily manufactured by previously installing the lens substrate 2 as a frame in the molding die 40.

  In the above description, the molding die 40 for manufacturing a single plastic lens 10 has been described. However, a large number of plastic lenses 10 can be obtained by adopting a mold structure in which a large number of plastic lenses 10 can be obtained. Can be provided at low cost for mass production.

  In the present embodiment, the optical resin covers the lens substrate back surface 2a of the lens substrate 2, so that even if the thickness variation of the lens substrate 2 occurs, the resin flows in to compensate for the variation. . Thereby, the thickness of the plastic lens 10 is determined by the alignment accuracy of the upper mold 41 and the lower mold 42 of the molding die 40, and a method for manufacturing the plastic lens 10 having high thickness accuracy can be provided. .

  Furthermore, by using an opaque material for the lens substrate 2, it is possible to provide a method of manufacturing the plastic lens 10 having a light shielding property.

  Further, since the molding die 40 and the lens substrate back surface 2a of the lens substrate 2 are not in direct contact, the force for closing the molding die 40 can be transmitted as pressure to the optical resin, and the optical resin is transferred to the molding die 40. The accuracy can be improved, and a method for manufacturing a high-quality plastic lens 10 can be provided.

  As described above, the plastic lens 10, the plastic lens wafer 20, the molding die 40, the plastic lens unit 31, the imaging device 30, the electronic device, and the manufacturing method of the plastic lens 10 according to the present embodiment are insert molding or two-color. When the lens substrate 2 is manufactured so that the lens optical resin extends on the lens substrate back surface 2a, which is one surface of the lens substrate 2, by optimizing the shape of the lens substrate 2, A plastic that suppresses warping caused by curing shrinkage of the optical resin and a difference in linear expansion coefficient between the lens material molded by the optical resin and the lens substrate 2 that is a frame material, and provides high performance and high reliability at low cost. Lens 10, plastic lens wafer 20, molding die 40, plastic lens unit 31, imaging device 30 A camera module having an optical element, which is an electronic device, and intended to provide a method of manufacturing a plastic lens 10.

  The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope shown in the claims, and can be obtained by appropriately combining technical means disclosed in the present embodiment. Such embodiments are also included in the technical scope of the present invention.

  With respect to the plastic lens wafer 20 shown in FIGS. 5A and 5B, the deformation amount and deformation mode in a normal temperature atmosphere were verified by a finite element method (FEM) and experiments. The finite element method (FEM) is a technique for dividing an analysis region into minimum unit regions called elements and approximating the potential distribution in each element with a simple function.

  Regarding the finite element method (FEM), analysis was performed on the models shown in FIGS. The perspective view of the surface of the plastic lens wafer 20 at this time is shown in FIG. 10A, and the back surface of the plastic lens wafer 20 is shown in FIG. In addition, assuming that there was no deformation immediately after mold release, the deformation amount when the molding temperature was changed from 150 ° C. to normal temperature (24 ° C.) was calculated.

  For deformation, the amount of deflection of the plastic lens wafer 20 shown in FIGS. 10A and 10B was evaluated. The linear expansion coefficient of the optical resin is 230 ppm / ° C., Young's modulus is 0.2 GP, and Poisson's ratio is 0.4. The lens substrate 2 has a diameter of 700 mm and a thickness of 0.5 mm, and the first through hole 1 has a diameter of 5.4 mm, and is provided at five locations as shown in FIG. The digging portions 6 provided in each of them had a diameter of 8.0 mm and a depth of 0.2 mm.

  The plastic lens wafer 20 was made of a material having a linear expansion coefficient of 47 ppm / ° C., a Young's modulus of 4.1 GPa, and a Poisson's ratio of 0.4.

  The optical resin extending on the back surface of the plastic lens wafer 20 is 30 mm × 30 mm and the thickness is 70 μm.

  At this time, in the structure in which the digging portion 6 is not provided, the amount of deflection at the warp measurement location shown in FIGS. 10A and 10B was 529 μm. On the other hand, in the structure in which the dug portion 6 is provided, the amount of deflection can be reduced to 93 μm.

  Based on the result of the analysis by the finite element method (FEM), a molding experiment was performed using the same model as described above. A laser focus displacement meter was used for measuring the warpage. The results at this time are shown in FIGS.

  That is, FIG. 11A shows the result of a structure in which the digging portion 6 is not provided, and the amount of deflection is 319 μm. On the other hand, FIG. 11B shows the result of the structure in which the dug portion 6 is provided, and the amount of deflection could be reduced to 90 μm.

  The plastic lens of the present invention can be suitably used as an optical element mounted on various optical devices.

DESCRIPTION OF SYMBOLS 1 1st through-hole 2 Lens board | substrate 2a Lens substrate back surface 2b Lens board | substrate surface 3 Lens effective diameter part 4 Lens ineffective diameter part 5 Optical resin extension part 6 Excavation part 7 2nd through-hole 8 Runner (groove)
DESCRIPTION OF SYMBOLS 9 Protrusion part 10 Plastic lens 16 Digging part 20 Plastic lens wafer 21 Spacer 22 Image pick-up element 30 Imaging device 31 Plastic lens unit 40 Molding die 41 Upper mold | die 41a Resin injection port 42 Lower mold | type

Claims (11)

A plastic lens comprising a lens substrate having a first through hole and a lens made of an optical resin,
The first through hole is filled with an optical resin, and the optical resin extends to cover the back surface of the lens substrate,
A plastic lens, wherein a digging portion filled with an optical resin is formed around the first through hole on the surface of the lens substrate. The digging portion of the lens substrate is provided with a second through hole penetrating the lens substrate,
The second through-hole is filled with an optical resin that connects the optical resin filled in the digging portion and the optical resin extending so as to cover the back surface of the lens substrate. The plastic lens according to claim 1. On the surface of the lens substrate, a groove that connects between the digging portion and the first through hole is formed,
The optical groove filling the groove is filled with an optical resin that communicates the optical resin filled in the digging portion and the optical resin formed in the first through hole of the lens substrate. 1. The plastic lens according to 1.   4. The plastic lens according to claim 1, wherein a projection is formed on at least one surface of the lens substrate.   5. The plastic lens according to claim 1, wherein the digging depth of the digging portion is ½ or less of the thickness of the lens substrate in the optical axis direction.   6. A plastic lens wafer, wherein the plastic lens according to claim 1 is molded in an array.   A molding die used for molding the plastic lens according to any one of claims 1 to 5.   A plastic lens unit comprising the plastic lens according to claim 1.   An imaging apparatus comprising the plastic lens unit according to claim 8.   An electronic apparatus comprising the imaging device according to claim 9.   8. A method for producing a plastic lens, comprising: arranging an optical resin in the first through hole and the digging portion after the lens substrate is disposed inside a molding die according to claim 7.