Wafer, method for manufacturing optical member, and mold
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SONY SEMICON SOLUTIONS CORP
- Filing Date
- 2025-11-25
- Publication Date
- 2026-07-16
Smart Images
Figure JP2025040998_16072026_PF_FP_ABST
Abstract
Description
Method for manufacturing wafers and optical components, and molds.
[0001] This technology relates to wafers. More specifically, it relates to wafers for manufacturing lenses and other optical components, manufacturing methods for optical components, and molds.
[0002] Conventionally, optical components such as lenses are often manufactured by molding thermoplastic resins. For example, a manufacturing method has been proposed in which lenses are manufactured by injection molding using a mold in which runners are formed along two orthogonal directions from the sprue (see, for example, Patent Document 1).
[0003] International Publication No. 2006-046436
[0004] In the conventional technology described above, the cavity is adjusted by simply adjusting the position of two orthogonal axes by forming runners along two orthogonal directions from the sprue. However, with the above manufacturing method, it is difficult to further miniaturize the lens. In addition, with the above manufacturing method, the number of lenses that can be manufactured in a single molding is about 16, and it is difficult to further increase that number.
[0005] This technology was developed in light of these circumstances, and aims to manufacture a large number of small optical components in a single molding process in a method for manufacturing optical components.
[0006] This technology was developed to solve the aforementioned problems, and its first aspect is a wafer comprising a disc-shaped gate portion, a sprue extending from the center of the gate portion along the central axis of the gate portion, a ring-shaped optical component arrangement portion without runners surrounding the gate portion, and a plurality of optical components arranged in the optical component arrangement portion, and a method for manufacturing the same. This results in the ability to manufacture a large number of small optical components in a single molding process.
[0007] Furthermore, in this first aspect, the thickness of the gate portion may be greater than the thickness of the optical element arrangement portion. This has the effect of facilitating the filling of thermoplastic resin.
[0008] Furthermore, in this first aspect, each of the above-mentioned optical components may be a lens. This has the effect of allowing a large number of small lenses to be manufactured in a single molding process.
[0009] Furthermore, in this first aspect, the number of lenses may be at least 16. This allows for the production of a large number of lenses in a single molding process.
[0010] Furthermore, in this first aspect, the central thickness of each of the lenses does not have to exceed 1 millimeter. This has the effect of enabling the manufacture of thin lenses.
[0011] Furthermore, in this first aspect, the lens includes a curved surface, and the arithmetic mean roughness of the surface of the curved surface does not need to exceed 10 nanometers. This results in the ability to manufacture high-quality lenses.
[0012] Furthermore, in this first aspect, the lens includes a curved portion, and the size of the curved portion in a predetermined direction perpendicular to the optical axis does not need to exceed 20 millimeters. This has the effect of enabling the manufacture of small lenses.
[0013] Furthermore, in this first aspect, the lens includes a curved portion, and when viewed from the optical axis direction, the curved portion may be circular or rectangular. This allows for the manufacture of lenses with rectangular or circular curved portions.
[0014] Furthermore, in this first aspect, each of the above-mentioned optical components may be an optical filter. This has the effect of allowing a large number of small optical filters to be manufactured in a single molding process.
[0015] Furthermore, in this first aspect, the wafer material may be a thermoplastic resin. This has the effect of facilitating the molding of the wafer.
[0016] Furthermore, in this first aspect, the optical element arrangement portion may be provided with protruding ribs formed along the outer circumference. This has the effect of improving the shape accuracy of the wafer.
[0017] Furthermore, in this first aspect, the ribs may be formed on one of the two sides of the optical element arrangement portion. This provides the effect of stabilizing the wafer during dicing.
[0018] Furthermore, in this first aspect, the thickness of the outer circumference of the optical element array portion on which the ribs are formed may be greater than the thickness of the optical element array portion inside the ribs, and less than the thickness of the gate portion. This has the effect of improving the shape accuracy of the wafer.
[0019] Furthermore, in this first aspect, the width of the rib may not exceed 5% of the wafer diameter. This has the effect of improving the shape accuracy of the wafer.
[0020] Furthermore, a second aspect of this technology is a mold comprising a circularly recessed wafer forming section, the wafer forming section comprising a predetermined number of optical element forming sections with shapes corresponding to the shapes of the optical elements, and the regions between the optical element forming sections being flat. This results in the formation of a wafer without runners between the optical elements.
[0021] Furthermore, in this second aspect, the wafer forming portion may further include grooves formed along the outer circumference of the wafer forming portion. This results in the formation of a wafer with ribs along its outer circumference.
[0022] This is an example of a top view and cross-sectional view of a wafer in the first embodiment of this technology. This is an example of an enlarged view of the wafer surface and a top view and cross-sectional view of a lens in the first embodiment of this technology. This is a diagram illustrating the lens manufacturing method in the first comparative example. This is a diagram illustrating the lens manufacturing method in the first embodiment of this technology. This is a diagram illustrating the compression molding method in the second comparative example. This is a diagram illustrating the effect of using a wafer in the first embodiment of this technology. This is a flowchart illustrating an example of a lens manufacturing method in the first embodiment of this technology. This is an example of an enlarged view and cross-sectional view of the wafer surface in the second embodiment of this technology. This is a diagram illustrating an example of the parameters of each lens in the second embodiment of this technology. This is an example of a top view and cross-sectional view of a wafer in the third embodiment of this technology. This is an example of a top view and cross-sectional view of an optical filter in the third embodiment of this technology. This is an example of a cross-sectional view of an imaging device in the third embodiment of this technology. This is an example of a top view and cross-sectional view of a wafer in the fourth embodiment of this technology. This is a diagram illustrating an example of rib thickness and rib width in the fourth embodiment of this technology. This is a diagram illustrating the effect and the shape of the movable side mold in the fourth embodiment of this technology. This figure shows an example of the amount of resin in the fourth embodiment of this technology. This figure shows an example of a rib in the fourth embodiment of this technology. This figure shows an example of rib thickness and rib width in the first modified example of the fourth embodiment of this technology. This is an example of a top view and cross-sectional view of a wafer in the second modified example of the fourth embodiment of this technology. This figure shows an example of rib thickness and rib width in the second modified example of the fourth embodiment of this technology.
[0023] The following describes embodiments for implementing this technology. The description will proceed in the following order: 1. First Embodiment (Example of forming a circular wafer without runners, on which lenses are arranged) 2. Second Embodiment (Example of forming a circular wafer without runners, on which three types of lenses are arranged) 3. Third Embodiment (Example of forming a circular wafer without runners, on which optical filters are arranged) 4. Fourth Embodiment (Example in which ribs are formed on the outer circumference of a circular wafer without runners, on which lenses are arranged)
[0024] <1. First Embodiment> [Example of Wafer Configuration] Figure 1 is an example of a top view and a cross-sectional view of a wafer 100 in the first embodiment of this technology. This wafer 100 is formed by a compression molding method when manufacturing multiple optical components, and comprises a sprue 110, a gate portion 120, and an optical component arrangement portion 130. These three parts are integrated and made of the same material, but in order to facilitate identification of each part, the gate portion 120 is painted in light gray and the sprue 110 is painted in dark gray in the figure. When a lens is manufactured as an optical component, the wafer 100 is called a lens wafer.
[0025] The gate portion 120 of the wafer 100 is a disc-shaped part. The sprue 110 is where the thermoplastic resin first flows in and extends from the center of the gate portion 120 along its central axis. The optical component arrangement portion 130 is a ring-shaped part surrounding the gate portion 120, and multiple optical components (such as lenses) are arranged in this portion. Furthermore, there are no runners between these optical components.
[0026] Hereinafter, the central axis of the gate portion 120 will be referred to as the "Z-axis." A predetermined axis perpendicular to the Z-axis will be referred to as the "X-axis," and an axis perpendicular to both the X-axis and the Z-axis will be referred to as the "Y-axis." Of the two sides of the gate portion 120, the side on which the sprue 110 is provided will be referred to as the top surface. The figure shows a top view from the Z-axis direction and a cross-sectional view from the Y-axis direction. The Z-axis and the optical axis of the optical element are parallel.
[0027] Furthermore, the thickness Tb of the gate portion 120 is greater than the thickness Ta of the optical element arrangement portion 130. For example, Ta is 0.44 millimeters (mm) and Tb is 1.30 millimeters (mm).
[0028] By making Tb larger than Ta, it becomes easier to fill the gate portion 120 with thermoplastic resin around it during molding.
[0029] Furthermore, the diameter Da of the wafer 100 is, for example, 75.75 millimeters (mm), and the diameter Db of the gate portion 120 is, for example, 15.9 millimeters (mm).
[0030] Figure 2 shows an example of an enlarged view of the wafer surface, a top view, and a cross-sectional view of the lens in the first embodiment of this technology. In the figure, a is an enlarged view of the portion of the optical element arrangement section 130 enclosed by the dotted line in Figure 1.
[0031] As illustrated in Figure 2a, multiple lenses 140 are arranged in the optical element arrangement section 130. These lenses 140 are arranged at regular intervals. The region between the lenses will be hereinafter referred to as the "interlens region." No runners are formed between the lenses, and each lens 140 is arranged so as to be surrounded by a flat interlens region. This interlens region is removed after dicing. The dashed line in Figure 2a indicates the cut line that is cut during dicing. Furthermore, the shape of each of the multiple lenses 140 is the same.
[0032] When runners are formed between lenses, the maximum number of lenses that can be manufactured in a single molding process is 16. In contrast, in the first embodiment, because the number of runners is reduced, more than 600 lenses can be manufactured in a single molding process. Furthermore, by reducing the number of runners, less waste material is produced compared to when runners are formed, thus reducing costs.
[0033] The distance between lenses in the X-axis direction is dX １ Let dY be the distance between the lenses in the Y-axis direction. １Let them be. For example, all of these values are 0.3 millimeters (mm). Also, let the distance between the centers of the lenses 140 in the X-axis direction be dX ２ and let the distance between the centers of the lenses 140 in the Y-axis direction be dY ２ Let them be. For example, all of these values are 2.445 millimeters (mm).
[0034] Each of the lenses 140 is separated into individual pieces by dicing. b in the figure is an example of a top view and a cross-sectional view of the separated lens 140. The lens 140 includes a curved surface portion 141 on at least one of its two surfaces and a flange portion 142 around it.
[0035] The curved surface portion 141 is circular when viewed from the optical axis direction, and both of its surfaces are curved surfaces. The outer periphery of the flange portion 142 (in other words, the outer periphery of the lens 140) is rectangular. Let the upper diameter of the curved surface portion 141 be Dc １ and the lower diameter be Dc ２ Let them be. Also, let Dc １ be larger than Dc ２ Let the central thickness of the lens 140 be Tc.
[0036] The number of lenses 140 arranged in the optical member array portion 130 is preferably 16 or more. For example, 636 lenses 140 are arranged on the wafer 100.
[0037] Also, the central thickness Tc of the lens 140 is preferably 1 millimeter or less. For example, Tc is set to 0.354 millimeters (mm).
[0038] Also, the arithmetic mean roughness Ra of the surface of the curved surface portion 141 of the lens 140 is preferably 10 nanometers (nm) or less. For example, Ra is set to 3 nanometers (nm).
[0039] Also, the diameters Dc １ and Dc ２ which are the sizes of the curved surface portion 141 in the direction perpendicular to the Z-axis direction (in other words, the optical axis direction) are both preferably 20 millimeters or less. For example, Dc １ is 0.875 millimeters and Dc２ It is 0.557 millimeters (mm).
[0040] The shape of the curved portion 141 of the lens 140 is not limited to a circle. The curved portion 141 can also be rectangular when viewed from the optical axis direction.
[0041] [Lens Manufacturing Method] As mentioned above, the wafer 100 is formed by compression molding, but as a first comparative example, we will consider a manufacturing method in which the wafer is formed by injection molding, as described in Patent Document 1.
[0042] As illustrated in Figure 3a, in the first comparative example, a fixed mold 210 and a movable mold 220 are provided. A sprue 211 for filling the thermoplastic resin is provided in the center of the fixed mold 210. A ring-shaped member 221 for damming the thermoplastic resin is provided in the movable mold 220.
[0043] Then, as illustrated in figure b, the movable mold 220 is pressed against the fixed mold 210, and a space is formed between them. This space is called a cavity. Then, thermoplastic resin 240 is injected from the sprue 211 along the Z-axis direction indicated by the white arrow by the molding machine 230, and the resin fills the cavity.
[0044] Then, as illustrated in figure c, the gate portion 212 is maintained at a constant pressure until it is sealed.
[0045] Then, as illustrated in figure d, the thermoplastic resin 240 is cooled and the wafer 100 is formed. Then, as illustrated in figure e, the wafer 100 is removed from the fixed mold 210 and the movable mold 220.
[0046] In the first comparative example described above, the distance Z between the fixed mold 210 and the movable mold 220 is shown at b in the figure. １Because the gap is very small, it is difficult to adequately fill it with the low-flow thermoplastic resin 240, resulting in poor lens transfer accuracy. Although there is a countermeasure of increasing the resin injection pressure, this causes the wafer 100 to warp significantly. Therefore, it is difficult to mold thin wafers 100 with a large surface area.
[0047] Next, a manufacturing method of the first embodiment using a compression molding method will be described.
[0048] Figure 4 is a diagram illustrating the manufacturing method of the lens 140 in the first embodiment of this technology.
[0049] As illustrated in figure a, a sprue 211 is provided in the center of the fixed mold 210. A ring-shaped member 221 is provided on the movable mold 220. This member 221 can be moved along the pressurizing direction by a spring.
[0050] Then, as illustrated in figure b, the movable mold 220 is pressed against the fixed mold 210, forming a space (i.e., a cavity) between them. Then, thermoplastic resin 240 is injected from the sprue 211 along the Z-axis direction indicated by the white arrow by the molding machine 230, and the resin fills the cavity.
[0051] Then, as illustrated in figure c, pressurization is performed by moving the movable mold 220 in the pressurizing direction, and the thermoplastic resin 240 is compressed. Then, holding pressure is performed.
[0052] Then, as illustrated in figure d, the movable mold 220 is moved in the opposite direction to the pressurizing direction to reduce pressure, and the thermoplastic resin 240 is cooled.
[0053] Then, as illustrated in figure e, the wafer 100 is removed from the fixed mold 210 and the movable mold 220.
[0054] In the figure, f is an example of an enlarged view of the surface of the wafer 100 in the first embodiment. As illustrated in figure f, in the first embodiment, no runners are formed between the lenses.
[0055] Then, each of the lenses 140 is separated into individual pieces by dicing.
[0056] In the first embodiment described above, at point b in the figure, the distance Z between the fixed mold 210 and the movable mold 220 is ２ This is the interval Z of the first comparative example. １ The dZ can be made larger than that. This makes it easier to fill the thermoplastic resin 240, and enables thinner and larger wafers 100 compared to the first comparative example.
[0057] Furthermore, at point c in the figure, the entire surface can be uniformly pressed, which enables thinning and high-precision transfer.
[0058] Furthermore, at point d in the figure, the reduced pressure can alleviate the stress within the wafer 100 and suppress its deformation.
[0059] Furthermore, since all lenses are molded using two molds (i.e., a fixed mold 210 and a movable mold 220), eccentricity adjustment can be easily performed, unlike injection molding which requires adjustment for each individual piece.
[0060] Furthermore, as a second comparative example, we consider a manufacturing method in which thermoplastic resin 240 is injected along a direction perpendicular to the pressurizing direction (such as the X-axis or Y-axis) when using compression molding.
[0061] Figure 5 is a diagram illustrating the compression molding method in the second comparative example. As illustrated in Figure a, in the second comparative example, a gate is provided on the side of the cavity, and thermoplastic resin 240 is injected along the X-axis direction perpendicular to the pressurizing direction. A square plate is then formed, for example.
[0062] In the figure, b indicates the direction of stress generated in the thermoplastic resin 240 near the gate of the second comparative example. Stress is generated along various directions of vectors v1, v2, and v3. The distance from the gate to the outer circumference of the plate differs in each of the directions v1, v2, and v3. For example, the distance to the outer circumference in the Z-axis direction v1 is shorter than the distance to the outer circumference in the X-axis direction v3. Due to these differences in distance, a pressure difference is generated at the outer circumference of the plate, resulting in residual stress. This residual stress may worsen the surface accuracy of the lens, mainly at the outer circumference of the plate.
[0063] Figure 6 is a diagram illustrating the effects of using wafer 100 in the first embodiment of this technology.
[0064] Unlike the second comparative example, in the first embodiment, as described above, the thermoplastic resin is injected along the Z-axis direction (in other words, the direction parallel to the pressurization direction). This resin spreads from the gate portion 120 in the center of the circular wafer 100 outwards within the cavity. Stress is generated along vectors v1, v2, v3, etc., from the gate portion 120 to the outer circumference of the wafer 100, but because the wafer 100 is circular, the distance from the gate portion 120 to the outer circumference of the wafer 100 is the same in each direction such as v1, v2, v3. Therefore, pressure differences are less likely to occur, and residual stress is suppressed. As a result, unlike the second comparative example, lenses can be formed with good surface accuracy even on the outer circumference of the wafer 100.
[0065] Figure 7 is a flowchart showing an example of a method for manufacturing the lens 140 in the first embodiment of this technology.
[0066] The wafer 100 is formed by compression molding (step S910), and each lens 140 is made into individual pieces by dicing (step S920).
[0067] In step S910, the movable mold 220 is pressed against the fixed mold 210 (step S911), and the thermoplastic resin 240 is filled (step S912). Then, the movement of the movable mold 220 compresses the thermoplastic resin 240, and holding pressure is performed (step S913). Then, the movement of the movable mold 220 reduces the pressure on the thermoplastic resin 240, and it is cooled (step S914). Finally, the wafer 100 is removed from the mold (step S915).
[0068] Thus, according to the first embodiment of this technology, since multiple lenses 140 are arranged on a circular wafer 100 with a sprue in the center without runners, a large number of thin, compact lenses 140 can be manufactured in a single molding process.
[0069] <2. Second Embodiment> In the first embodiment described above, the shapes of the multiple lenses 140 were all the same, but the embodiment is not limited to this configuration. The wafer 100 in this second embodiment differs from the first embodiment in that it has three types of lenses with different shapes arranged on it.
[0070] Figure 8 shows an example of an enlarged view and a cross-sectional view of the wafer surface in a second embodiment of the present technology. In the second embodiment, lenses 140, 150, and 160 of different shapes are arranged on the surface of the wafer 100. Lens 140 has a curved portion 141 and a flange portion 142, lens 150 has a curved portion 151 and a flange portion 152, and lens 160 has a curved portion 161 and a flange portion 162.
[0071] When viewed from the direction of the optical axis, the curved portions 141 and 142 are circular, and the diameter of the curved portion 151 is larger than the diameter of the curved portion 141. Also, when viewed from the direction of the optical axis, the curved portion 161 is rectangular.
[0072] Furthermore, the distance between these lenses in the X-axis direction is dX １ Therefore, the distance between lenses in the Y-axis direction is dX １ It is the same as, for example, 0.3 millimeters (mm).
[0073] Furthermore, the thickness Tb of the gate portion 120 is greater than the thickness Ta of the optical element arrangement portion 130. For example, Ta is 0.37 millimeters (mm) and Tb is 0.80 millimeters (mm).
[0074] Furthermore, the diameter Da of the wafer 100 is, for example, 75.75 millimeters (mm), and the diameter Db of the gate portion 120 is, for example, 15.9 millimeters (mm).
[0075] Although three lenses of different shapes are arranged on the wafer 100, the configuration is not limited to this. Two lenses of different shapes may be arranged, or four or more lenses of different shapes may be arranged.
[0076] Figure 9 shows an example of the parameters of each lens in the second embodiment of this technology. Lens 140 is the first lens, lens 150 is the second lens, and lens 160 is the third lens.
[0077] The total number of lenses is preferably 16 or more. For example, the first lens, second lens, and third lens are arranged in quantities of 370 each.
[0078] Furthermore, the center thickness of each lens is preferably 1 millimeter (mm) or less. For example, the center thickness of the first lens is 0.136 millimeters (mm), and the center thickness of the second lens is 0.173 millimeters (mm). For example, the center thickness of the third lens is 0.193 millimeters (mm).
[0079] The arithmetic mean roughness Ra of the first lens, second lens, and third lens is preferably 10 nanometers (nm) or less. For example, Ra is 5 nanometers (nm) for all of them.
[0080] Furthermore, the size of each curved surface in the direction perpendicular to the optical axis is preferably 20 millimeters (mm) or less. The diameter of the curved surface 141 of the first lens is, for example, 0.478 millimeters (mm), and the diameter of the curved surface 151 of the second lens is, for example, 0.658 millimeters (mm). The diagonal length of the curved surface 161 of the third lens is, for example, 1.34 millimeters (mm).
[0081] Thus, according to the second embodiment of this technology, since three types of lenses with different shapes are arranged on the wafer 100, three types of lenses can be manufactured in a single molding process.
[0082] <3. Third Embodiment> In the first embodiment described above, lenses were arranged on the wafer 100, but the optical elements arranged on the wafer 100 are not limited to lenses. The wafer 100 in this third embodiment differs from the first embodiment in that optical filters are arranged on it.
[0083] Figure 10 shows an example of a top view and a cross-sectional view of a wafer 100 in a third embodiment of the present technology. The wafer 100 in this third embodiment differs from the first embodiment in that optical filters 170 are arranged instead of lenses. An example of an optical filter 170 is an infrared cut filter.
[0084] Furthermore, the thickness Tb of the gate portion 120 is greater than the thickness Ta of the optical element arrangement portion 130. For example, Ta is 0.20 millimeters (mm) and Tb is 0.60 millimeters (mm).
[0085] Furthermore, the diameter Da of the wafer 100 is, for example, 152 millimeters (mm), and the diameter Db of the gate portion 120 is, for example, 31.8 millimeters (mm).
[0086] Figure 11 shows an example of a top view and a cross-sectional view of an optical filter 170 in a third embodiment of the present technology. The optical filter 170 has a curved surface portion 171 and a flange portion 172. When viewed from the optical axis direction, the shape of the curved surface portion 171 is rectangular, and the outer circumference of the optical filter 170 is also rectangular.
[0087] The size Dx of the curved surface 171 in the X-axis direction is, for example, 15.73 millimeters (mm), and the size Dy of the curved surface 171 in the Y-axis direction is, for example, 12.34 millimeters (mm).
[0088] Furthermore, it is preferable that the number of optical filters 170 be 16 or more. For example, 62 optical filters 170 are arranged on the wafer 100.
[0089] Furthermore, the central thickness Td of the optical filter 170 is preferably 1 millimeter (mm) or less. For example, Td is set to 0.204 millimeters (mm).
[0090] Furthermore, the arithmetic mean roughness Ra of the curved surface portion 171 is preferably 10 nanometers (nm) or less.
[0091] Furthermore, the size of the curved portion 171 in the direction perpendicular to the optical axis is preferably 20 millimeters (mm) or less. For example, the length of the diagonal of the curved portion 171 is, for example, 20 millimeters (mm).
[0092] Figure 12 is an example of a cross-sectional view of an imaging device in a third embodiment of this technology. The figure shows a cross-sectional view of the imaging device as seen from the Y-axis direction. This imaging device includes lenses 140, 150, and 160, an optical filter 170, and an image sensor 180. Lenses 140, 150, and 160 are manufactured, for example, by wafer dicing as in the second embodiment. The imaging device is installed in a mobile device such as a smartphone or an HMD (Head Mounted Display).
[0093] From the object side, the optical components are arranged on the image plane side of the image sensor 180 in the order of lens 140, lens 150, lens 160, and optical filter 170.
[0094] Thus, according to the third embodiment of this technology, since a wafer 100 on which optical filters 170 are arranged is formed, a thin and compact optical filter 170 can be manufactured in a single molding process.
[0095] <4. Fourth Embodiment> In the first embodiment described above, the wafer 100 was formed by a compression molding method, but it is preferable to further improve the shape accuracy of the wafer 100 and optical components. The wafer 100 in this fourth embodiment differs from that of the first embodiment in that protruding ribs are formed on the outer circumference.
[0096] Figure 13 shows an example of a top view and a cross-sectional view of a wafer 100 in a fourth embodiment of the present technology. The optical element array portion 130 in the fourth embodiment differs from the first embodiment in that it includes protruding ribs 131 formed along its outer circumference. The material of the ribs 131 is the same as that of the other parts and is integrated with the surrounding area, but in order to facilitate identification, the ribs 131 are filled in with dark gray and the other parts are filled in with light gray in the figure.
[0097] The ribs 131 can be formed on both sides of the wafer 100, but it is preferable to form them on only one side. By forming the ribs 131 on only one side of the wafer 100, the area near the outer edge of the other side becomes flat, which stabilizes the wafer 100 during dicing.
[0098] Hereinafter, the thickness of the outer circumference of the optical element array portion 130 on which the ribs 131 are formed will be defined as the rib thickness Tc. The thickness of the optical element array portion 130 inside the ribs 131 will be defined as the wafer thickness Ta, and the thickness of the gate portion 120 will be defined as the gate thickness Tb. Furthermore, the diameter of the wafer 100 will be defined as Da, and the width of the ribs 131 will be defined as the rib width W.
[0099] As illustrated in Figure 14, the rib thickness Tc is preferably greater than the wafer thickness Ta and smaller than the gate thickness Tb. Furthermore, the rib width W is preferably 5% or less of the diameter Da of the wafer 100.
[0100] For example, if the wafer thickness Ta is 0.44 mm and the gate thickness Tb is 1.30 mm, the rib thickness Tc is set to 1.00 mm. Also, if the diameter Da of wafer 100 is 75.75 mm, the rib width W is set to 2.00 mm.
[0101] Figure 15a shows an example of the movable mold 220 and fixed mold 210 before compression. Figure 15b shows an example of the movable mold 220 and fixed mold 210 during compression. Figure 15c shows a cross-sectional view of the movable mold 220.
[0102] As illustrated in figure c, the movable mold 220 has a circularly recessed wafer forming portion 222 when viewed from the Z-axis direction (i.e., the pressurizing direction). Along the outer circumference of this wafer forming portion 222, a groove with a rectangular cross-sectional shape when viewed from the X-axis direction and the Y-axis direction is formed, and this portion is called the groove portion 223. The aforementioned rib 131 is formed by the groove portion 223. In addition, a predetermined number of optical element forming portions 224, corresponding to the shape of an optical element (such as a lens), are formed inside the groove portion 223. Since no runner is formed, the area between these optical element forming portions 224 is flat. On the other hand, no groove portion is formed in the fixed mold 210. When forming the rib 131 on the fixed side, a groove portion is formed only in the fixed mold 210.
[0103] Furthermore, during compression molding, the thermoplastic resin 240 is injected into the cavity as illustrated in figure a, and compressed as illustrated in figure b. At this time, the grooves 223 function as resin reservoirs, and excess resin enters the grooves 223, making it easier to thin the wafer 100. Moreover, even when a thin wafer 100 is formed, the ribs 131 maintain the rigidity of the wafer 100, suppressing warping of the wafer 100. As a result, optical components (such as lenses) can be manufactured with high precision.
[0104] Furthermore, even if the amount of resin injected during compression varies, the groove 223 corresponding to the rib 131 can absorb the variation.
[0105] For example, as illustrated in Figure 16a, if the amount of resin is less than the appropriate amount, the thermoplastic resin 240 will not be pushed into the corners of the groove 223, resulting in an untransferred state. Figure 16b shows the case where the amount of resin is appropriate. As illustrated in Figure 16c, if the amount of resin is more than the appropriate amount, the thermoplastic resin 240 will be pushed into the corners of the groove 223.
[0106] For example, if the wafer thickness is 0.44 mm, the rib thickness is 1.00 mm, the diameter of wafer 100 is 75.75 mm, and the rib width is 2.00 mm, then the volume of rib 131 is approximately 131.51 cubic millimeters. ３ ) and the volume of wafer 100 is approximately 2153.69 cubic millimeters (mm ３ In this example, the volume of the rib 131 is 6% or less of the total volume of the wafer 100. Since the variation in resin volume during typical compression molding is ±3%, the groove 223 can sufficiently absorb the variation in resin volume. This makes it possible to achieve a highly robust structure.
[0107] Furthermore, while transferring the necessary parts other than the rib 131, the molding can be performed with low pressure, such that the resin is not pushed all the way into the corners of the groove 223. This reduces stress during molding and improves the shape accuracy of the optical component.
[0108] In the figure, at points a and b, shorting occurs, a phenomenon in which part of the shape is lost due to low-pressure molding. In addition, as illustrated in point d of the figure, sink marks may occur, a phenomenon in which the surface becomes concave due to the shrinkage of the thermoplastic resin 240. However, since the ribs 131 are removed by dicing, transfer accuracy is not required, and the occurrence of shorting or sink marks is not a problem.
[0109] In Figure 13, the cross-sectional shape of the rib 131 is rectangular. However, in this case, the side surface of the rib 131 is parallel to the direction of release (Z-axis direction), and when the wafer 100 is released from the mold, the release resistance of the side surface may cause the wafer 100 to deform. For this reason, it is preferable to add a draft angle to the side surface of the rib 131.
[0110] For example, as illustrated in Figure 17a, the cross-sectional shape of the rib 131 is preferably triangular. Alternatively, as illustrated in Figure 17b, the cross-sectional shape of the rib 131 is preferably trapezoidal. With these shapes, a draft angle can be applied, which reduces the release resistance and suppresses deformation of the wafer 100, thereby improving shape accuracy. Although Figures a and b show examples where no untransferred areas occur, it is not a problem if shorts or sink marks occur in these ribs 131.
[0111] Thus, according to the fourth embodiment of this technology, since ribs 131 are formed along the outer circumference of the wafer 100, the shape accuracy of the optical element can be improved.
[0112] [First Modification] The second embodiment, in which a plurality of lenses of different shapes are arranged, can be applied to the fourth embodiment described above. The wafer 100 in this first modification of the fourth embodiment differs from that of the fourth embodiment in that the second embodiment is applied.
[0113] The shape of each lens in the first modification of the fourth embodiment is the same as that illustrated in Figure 8, for example.
[0114] Figure 18 shows an example of rib thickness and rib width in the first modified example of the fourth embodiment of this technology. In the first modified example of the fourth embodiment, the rib thickness is preferably greater than the wafer thickness and smaller than the gate thickness. The rib width is preferably 5% or less of the diameter of the wafer 100.
[0115] For example, if the wafer thickness is 0.37 mm and the gate thickness is 0.90 mm, the rib thickness will be set to 0.70 mm. Also, if the diameter of wafer 100 is 37.90 mm, the rib width will be set to 0.50 mm.
[0116] Thus, according to the first modification of the fourth embodiment of this technology, since multiple lenses of different shapes are arranged on the wafer 100, these lenses can be manufactured in a single molding process.
[0117] [Second Modification] The third embodiment, in which optical filters 170 are arranged, can also be applied to the fourth embodiment described above. The wafer 100 in this second modification of the fourth embodiment differs from that of the fourth embodiment in that the third embodiment is applied.
[0118] Figure 19 shows an example of a top view and a cross-sectional view of a wafer 100 in a second modification of the fourth embodiment of the present technology. The wafer 100 in this second modification of the fourth embodiment differs from the fourth embodiment in that optical filters 170 are arranged instead of lenses. An example of an optical filter 170 is an infrared cut filter. The shape of the optical filter 170 is similar to that illustrated in Figure 11, for example.
[0119] Figure 20 shows an example of rib thickness and rib width in a second modification of the fourth embodiment of this technology. In the second modification of the fourth embodiment, the rib thickness is preferably greater than the wafer thickness and smaller than the gate thickness. The rib width is preferably 5% or less of the diameter of the wafer 100.
[0120] For example, if the wafer thickness is 0.20 mm and the gate thickness is 0.70 mm, the rib thickness will be set to 0.60 mm. Also, if the diameter of wafer 100 is 76.00 mm, the rib width will be set to 3.00 mm.
[0121] Thus, according to the second modification of the fourth embodiment of this technology, in order to form a wafer 100 on which optical filters 170 are arranged, a thin and compact optical filter 170 can be manufactured in a single molding process.
[0122] The embodiments described above are merely examples of how to realize this technology, and there is a corresponding relationship between the matters in the embodiments and the inventive features in the claims. Similarly, there is a corresponding relationship between the inventive features in the claims and the matters in the embodiments of this technology that bear the same name. However, this technology is not limited to the embodiments and can be realized by making various modifications to the embodiments without departing from the gist of the technology.
[0123] The effects described herein are merely illustrative and not limited to those described herein, and other effects may also occur.
[0124] Furthermore, this technology can also take the following configurations: (1) A wafer comprising a disc-shaped gate portion, a sprue extending from the center of the gate portion along the central axis of the gate portion, a ring-shaped optical element array portion without runners surrounding the gate portion, and a plurality of optical elements arranged in the optical element array portion. (2) The wafer according to (1), wherein the thickness of the gate portion is greater than the thickness of the optical element array portion. (3) The wafer according to (1) or (2), wherein each of the plurality of optical elements is a lens. (4) The wafer according to (3), wherein the number of lenses is at least 16. (5) The wafer according to (3) or (4), wherein the central thickness of each of the lenses does not exceed 1 millimeter. (6) The wafer according to (3) to (5), wherein the lenses include a curved surface portion, and the arithmetic mean roughness of the surface of the curved surface portion does not exceed 10 nanometers. (7) The wafer according to any one of (3) to (6), wherein the lens includes a curved portion, and the size of the curved portion in a predetermined direction perpendicular to the optical axis does not exceed 20 millimeters. (8) The wafer according to any one of (3) to (7), wherein the lens includes a curved portion, and the curved portion is circular or rectangular when viewed from the direction of the optical axis. (9) The wafer according to (1), wherein each of the plurality of optical members is an optical filter. (10) The wafer according to any one of (1) to (9), wherein the material of the wafer is a thermoplastic resin. (11) The wafer according to any one of (1) to (10), wherein the optical member array portion is provided with protruding ribs formed along the outer circumference. (12) The wafer according to (11), wherein the ribs are formed on one of the two sides of the optical member array portion. (13) The wafer according to (11) or (12), wherein the thickness of the outer circumference of the optical member array portion on which the ribs are formed is greater than the thickness of the optical member array portion inside the ribs and less than the thickness of the gate portion. (14) The wafer according to any one of (11) to (13) above, wherein the width of the ribs does not exceed 5% of the diameter of the wafer.(15) A method for manufacturing an optical member, comprising: a molding procedure for forming a wafer having a disc-shaped gate portion, a sprue extending from the center of the gate portion along the central axis of the gate portion, a ring-shaped optical member arrangement portion without a runner surrounding the gate portion, and a plurality of optical members arranged in the optical member arrangement portion; and a framing procedure for framing the plurality of optical members. (16) The method for manufacturing an optical member according to (15), wherein in the molding procedure, the wafer is formed by a compression molding method. (17) The method for manufacturing an optical member according to (16), wherein the molding procedure comprises: a filling procedure for filling a cavity between a movable mold and a fixed mold with thermoplastic resin in a direction parallel to a predetermined pressurizing direction; a pressurizing procedure for applying pressure by moving the movable mold in the pressurizing direction; a depressurizing procedure for applying pressure and cooling the thermoplastic resin by moving the movable mold in the opposite direction to the pressurizing direction; and a demolding procedure for removing the wafer made of the thermoplastic resin from the movable mold and the fixed mold. (18) The method for manufacturing an optical member according to (17), wherein one of the movable mold and the fixed mold is provided with a circularly recessed wafer forming portion, the wafer forming portion comprises a groove formed along the outer circumference of the wafer forming portion and a predetermined number of optical member forming portions having a shape corresponding to the shape of the optical member, and the region between the optical member forming portions is flat. (19) A mold comprising a circularly recessed wafer forming portion, the wafer forming portion comprising a predetermined number of optical member forming portions having a shape corresponding to the shape of the optical member, and the region between the optical member forming portions is flat. (20) The mold according to (19), wherein the wafer forming portion is further provided with a groove formed along the outer circumference of the wafer forming portion.
[0125] 100 Wafer 110 Sprue 120 Gate section 130 Optical component arrangement section 131 Rib 140, 150, 160 Lens 141, 151, 161, 171 Curved section 142, 152, 162, 172 Flange section 170 Optical filter 180 Image sensor 210 Fixed mold 211 Sprue 212 Gate section 220 Movable mold 221 Component 222 Wafer forming section 223 Groove section 224 Optical component forming section 230 Molding machine 240 Thermoplastic resin
Claims
1. A wafer comprising a disc-shaped gate portion, a sprue extending from the center of the gate portion along the central axis of the gate portion, a ring-shaped optical element arrangement portion without runners surrounding the gate portion, and a plurality of optical elements arranged in the optical element arrangement portion.
2. The wafer according to claim 1, wherein the thickness of the gate portion is greater than the thickness of the optical element arrangement portion.
3. The wafer according to claim 1, wherein each of the plurality of optical elements is a lens.
4. The wafer according to claim 3, wherein the number of lenses is at least 16.
5. The wafer according to claim 3, wherein the central thickness of each of the lenses does not exceed 1 millimeter.
6. The wafer according to claim 3, wherein the lens includes a curved portion, and the arithmetic mean roughness of the surface of the curved portion does not exceed 10 nanometers.
7. The wafer according to claim 3, wherein the lens includes a curved portion, and the size of the curved portion in a predetermined direction perpendicular to the optical axis does not exceed 20 millimeters.
8. The wafer according to claim 3, wherein the lens includes a curved portion, and the curved portion is circular or rectangular when viewed from the optical axis direction.
9. The wafer according to claim 1, wherein each of the plurality of optical elements is an optical filter.
10. The wafer according to claim 1, wherein the material of the wafer is a thermoplastic resin.
11. The wafer according to claim 1, wherein the optical element arrangement portion comprises protruding ribs formed along the outer circumference.
12. The wafer according to claim 11, wherein the ribs are formed on one of the two sides of the optical element arrangement portion.
13. The wafer according to claim 11, wherein the thickness of the outer circumference of the optical element array portion on which the ribs are formed is greater than the thickness of the optical element array portion inside the ribs and less than the thickness of the gate portion.
14. The wafer according to claim 11, wherein the width of the ribs does not exceed 5% of the diameter of the wafer.
15. A method for manufacturing an optical component, comprising: a molding procedure for forming a wafer having a disc-shaped gate portion, a sprue extending from the center of the gate portion along the central axis of the gate portion, a ring-shaped optical component arrangement portion without runners surrounding the gate portion, and a plurality of optical components arranged in the optical component arrangement portion; and a framing procedure for framing the plurality of optical components.
16. The method for manufacturing an optical member according to claim 15, wherein the wafer is formed by a compression molding method in the molding procedure.
17. The method for manufacturing an optical member according to claim 15, wherein the molding procedure comprises: a filling procedure for filling a cavity between a movable mold and a fixed mold with a thermoplastic resin in a direction parallel to a predetermined pressurizing direction; a pressurizing procedure for applying pressure by moving the movable mold in the pressurizing direction; a depressurizing procedure for applying pressure and cooling the thermoplastic resin by moving the movable mold in the opposite direction to the pressurizing direction; and a demolding procedure for removing the wafer made of the thermoplastic resin from the movable mold and the fixed mold.
18. The method for manufacturing an optical member according to claim 17, wherein one of the movable mold and the fixed mold is provided with a circularly recessed wafer forming portion, the wafer forming portion comprises a groove formed along the outer circumference of the wafer forming portion and a predetermined number of optical member forming portions having a shape corresponding to the shape of the optical member, and the region between the optical member forming portions is flat.
19. A mold comprising a circularly recessed wafer forming portion, wherein the wafer forming portion comprises a predetermined number of optical element forming portions having a shape corresponding to the shape of an optical element, and the region between the optical element forming portions is flat.
20. The mold according to claim 19, wherein the wafer forming portion further comprises a groove formed along the outer circumference of the wafer forming portion.