JP5165703B2 - Optical element array, optical element array mold, and optical element unit - Google Patents

Description

  The present invention relates to an optical element array in which a plurality of optical elements are molded on the same surface of a wafer made of a molded object such as resin, an optical element array mold used for molding the optical element array, and the optical element array. It is invention regarding the optical element unit manufactured using the optical element shape | molded in this.

  Imaging modules include compact digital cameras and digital video units with built-in solid-state imaging devices such as CCD (Charge Coupled Device) and CMOS (Complementary Metal Oxide Semiconductor). Have been developed. In particular, in recent years when various portable terminals such as portable information terminals and portable telephones have become widespread, imaging modules mounted on them are required to have low resolution as well as high resolution. ing.

  As a technique capable of satisfying the above requirement for low cost, a technique for reducing the manufacturing cost of an imaging lens (optical element unit) provided in the imaging module has attracted attention. As an example of such a technique, Patent Documents 1 and 2 disclose a technique for manufacturing an imaging lens by a manufacturing process called a wafer level lens process.

  The wafer level lens process is to mold or shape a plurality of optical elements such as lenses on the same surface of a wafer made of a molded object such as a resin, thereby forming a lens array (optical element array). This is a manufacturing process in which an imaging lens is manufactured by preparing a plurality of lens arrays and bonding them together and then dividing each lens array. According to this manufacturing process, a large number of imaging lenses can be manufactured in a short time in a short time, so that the manufacturing cost of the imaging lens can be reduced. Here, the lens array can be manufactured by, for example, transferring a shape opposite to the mold to the wafer using a mold (optical element array mold).

  Further, in the techniques according to Patent Documents 1 and 2, in order to prevent an error that occurs between the position where the shape of the transfer body is transferred and a desired position, the transfer is performed in accordance with the shrinkage of the photocurable resin used. The pitch of the position where the body comes into contact with the photocurable resin can be changed.

JP 2009-018578 A (published January 29, 2009) Japanese Unexamined Patent Publication No. 2009-023353 (published February 5, 2009)

  In a wafer level lens process for producing a lens array, the degree of contraction of the lens array is not uniform due to various conditions such as temperature variations during molding of the lens array. There is a concern that the distance between two adjacent lenses molded in the above may vary. The pitch error between the lenses in the lens array due to the variation in the distance between the adjacent two lenses becomes the eccentricity between both surfaces of the lens or between the lenses constituting the imaging lens. Affects decline.

  In other words, the degree of contraction of the lens array that contributes to the variation in the distance between two adjacent lenses is not always uniform throughout the lens array depending on the process conditions. For this reason, in the technology according to Patent Documents 1 and 2 in which the pitch of the position where the transfer body contacts the photocurable resin is changed in accordance with the shrinkage of the photocurable resin to be used, There arises a problem that variations occur in the interval, and this variation is likely to cause a pitch error between the lenses in the lens array.

  When an imaging lens is manufactured by a wafer level lens process using a lens array in which a pitch error has occurred, in this imaging lens, the relative positional relationship of each provided lens is determined from a desired positional relationship. This causes a problem that the optical characteristics may be deteriorated due to the occurrence of eccentricity.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to use an optical element array that can suppress pitch errors in each molded optical element, and to mold this optical element array. An object of the present invention is to provide an optical element array mold and an optical element unit manufactured by using the optical elements formed in the optical element array.

  In the optical element array of the present invention, in order to solve the above problems, a plurality of optical elements are formed on the same surface, and two adjacent optical elements in the plurality of optical elements are either of the optical elements. An optical element array formed by being spaced apart in a normal direction with respect to a reference optical axis that is an optical axis of the element, wherein an inclination with respect to the normal direction is smaller than a predetermined angle or an inclination angle is 0 ° A flat portion and an inclined portion having an inclination angle with respect to the normal direction larger than the flat portion are provided on the front surface and the back surface, and at least one of the front surface and the back surface is between the optical axes of the two adjacent optical elements. The width of the flat portion is not more than the width of the inclined portion.

  The inventors of the present application, when molding into an optical element array such as a wafer (molded object), in the optical element array, the portion where the inclination with respect to the normal direction with respect to the optical axis of the optical element is larger is in the normal direction. As a result of finding that the generated stress increases and the degree to which contraction in the normal direction is restricted increases, the present invention has been devised.

  That is, according to the above configuration, between the optical axes of the two adjacent optical elements, it is possible to generate a large stress in the normal direction with a width of the flat portion where it is difficult to generate a large stress in the normal direction. By reducing the width to be equal to or less than the width of the inclined portion that can be reduced, it is possible to narrow the region where the influence of the constraint (restriction of shrinkage) due to the stress in the normal direction is small. As a result, in the optical element array of the present invention, when two adjacent optical elements are separated by a predetermined pitch in the normal direction, the degree of contraction in the normal direction is reduced. The fluctuation range of the pitch error between the molded optical elements can be reduced.

  Therefore, in the optical element array of the present invention, the pitch error (the pitch variation between the optical elements) can be satisfactorily suppressed.

  The optical element array of the present invention is characterized in that the inclined portion has an inclination angle of 10 ° or more with respect to the normal direction.

  According to the above configuration, a large stress can be generated in the inclined portion to a degree sufficient for restricting the contraction.

  In the optical element array of the present invention, the flat portion has an inclination angle with respect to the normal direction of less than 10 °.

  According to said structure, the area | region applicable to a flat part can be narrowed sufficiently and easily.

  In addition, the optical element array of the present invention is characterized in that, in each of the molded optical elements, the variation in PV (Peak to Valley) value is optimized.

  Here, the PV value indicates surface accuracy (shape accuracy). In particular, in the present application, the maximum error of the shape of the optical surface of the optical element with respect to the design value is indicated.

  According to the above configuration, by sufficiently optimizing the PV value in advance to produce the optical element array of the present invention, sufficiently precise shape accuracy can be realized in the optical element array of the present invention.

  In particular, in the optical element array of the present invention, the variation in the PV value is preferably within 0.5 μm, thereby realizing an optical element array having a very high quality in terms of shape accuracy. it can.

  The optical element array of the present invention is characterized in that an unevenness extending in the direction of the reference optical axis is formed between the two adjacent optical elements.

  According to the above configuration, by forming the unevenness extending in the direction of the reference optical axis, it becomes possible to further narrow the region of the flat portion, and therefore further increase the pitch error (the pitch variation between the optical elements). It becomes possible to suppress well. Further, the unevenness of the optical element can be used as a member for adjusting the distance between the optical element and the other member by contacting with the other member.

  The optical element array mold according to the present invention is an optical element array mold that sandwiches a wafer between opposite surfaces and molds the wafer into the optical element array according to the present invention. A flat molded part that molds into the flat part between the optical axes of two optical elements; and an inclined molded part that molds the wafer into the inclined part between the optical axes of the two adjacent optical elements. In addition, the width of the flat molded portion is equal to or less than the width of the inclined molded portion on at least one of the both surfaces.

  According to said structure, it becomes possible to shape | mold the optical element array of this invention in which the pitch error (the pitch variation between each optical element) was suppressed favorably using an optical element array shaping | molding die.

  Further, the optical element unit of the present invention uses a plurality of optical element arrays of the present invention so that the optical axes of one optical element molded in each optical element array are located on the same straight line. In addition, after the optical element arrays are bonded together, they are obtained as a result of dividing each optical element combination whose optical axes are located on the same straight line as a unit.

  Since the optical element formed in the optical element array of the present invention has a favorable pitch error, an optical element unit having a complicated configuration including a plurality of optical elements is manufactured by a wafer level lens process. Is suitable.

  According to the above configuration, the optical element unit of the present invention is manufactured by a wafer level lens process using a plurality of optical element arrays of the present invention. It becomes possible to manufacture in a short time, and it becomes possible to reduce manufacturing cost. Therefore, an inexpensive optical element unit can be realized.

  In the optical element unit of the present invention, the first optical element which is one of the combinations has a protrusion formed on the outer peripheral portion of the effective aperture, and the protrusion of the first optical element and the other of the combination The second optical element is abutted in the optical axis direction of the first optical element.

  The optical element unit of the present invention further includes an aperture stop, and the second optical element has a protrusion formed on the outer peripheral portion of the effective aperture, and the protrusion of the second optical element and the aperture stop Are in contact with each other in the optical axis direction of the second optical element.

  The optical element unit of the present invention further includes an aperture stop, and at least one of the optical elements has a protrusion formed on the outer peripheral portion of the effective aperture, and the protrusion of the optical element, the aperture stop, Is abutted in the optical axis direction of the optical element.

  According to the above configuration, the other optical element and / or the aperture stop is brought into contact with the protruding portion of the optical element, the effective aperture of the optical element, the effective aperture and / or the aperture stop of the other optical element, By adjusting the distance in the optical axis direction, the distance can be easily adjusted.

  In the optical element unit of the present invention, the protrusion extends in the direction of the reference optical axis formed between two molded optical elements in the optical element array in which the corresponding optical elements are molded. It is characterized by unevenness.

  According to said structure, the unevenness | corrugation formed in the optical element array of this invention can be utilized as a protrusion part.

  As described above, in the optical element array of the present invention, a plurality of optical elements are formed on the same surface, and two adjacent ones of the plurality of optical elements are optical axes of the optical elements. An optical element array that is formed separately from each other in a normal direction with respect to a reference optical axis, and a flat portion having an inclination with respect to the normal direction smaller than a predetermined angle or an inclination angle of 0 °, An inclined portion having an inclination angle with respect to the normal direction larger than the flat portion is provided on the front surface and the back surface, and at least one of the front surface and the back surface is between the optical axes of the two adjacent optical elements. The width is equal to or smaller than the width of the inclined portion.

  Therefore, the present invention has an effect that it is possible to suppress a pitch error in each molded optical element.

It is sectional drawing which shows the structure of the lens array which concerns on one embodiment of this invention. It is sectional drawing which shows the structure of the lens array which concerns on another embodiment of this invention. It is sectional drawing which shows the structure of the imaging lens which concerns on one embodiment of this invention. FIG. 3 is a cross-sectional view illustrating an example of a method for manufacturing an imaging module using the lens array of the present invention, and illustrating a process of forming a wafer into the lens array illustrated in FIG. 2. It is sectional drawing which shows an example of the method of manufacturing an imaging module using the lens array of this invention, and shows the process of bonding several lens arrays. An example of a method for manufacturing an imaging module using the lens array of the present invention is shown, and is a cross-sectional view showing a process of cutting a plurality of bonded lens arrays for each imaging module. It is sectional drawing which shows the structure of the imaging module completed through each process shown in FIGS.

  Hereinafter, embodiments of the present invention will be described in detail.

[Configuration 1 of Optical Element Array of the Present Invention]
FIG. 1 is a cross-sectional view showing a configuration of a lens array according to an embodiment of the present invention.

  A lens array (optical element array) 100 shown in FIG. 1 is formed by molding a plurality of lenses (optical elements) on the same surface of a wafer 40. For the sake of convenience, FIG. 1 shows only two specific adjacent lenses (optical elements) 10 and 20 among a plurality of lenses.

  The lenses 10 and 20 are formed so as to be spaced apart from each other at a predetermined pitch of 50 in the normal direction with respect to the optical axis (reference optical axis) 11 of the lens 10. In particular, in FIG. 1, since the optical axis 21 of the lens 20 is parallel to the optical axis 11, the lenses 10 and 20 have a predetermined pitch 50 with respect to each other in the normal direction to the optical axis 21 of the lens 20. It can also be interpreted as being molded at intervals. That is, the lenses 10 and 20 are molded in a normal direction with respect to either one of the optical axes 11 and 21 with a predetermined pitch of 50.

  In FIG. 1, the Z direction indicates the direction in which the optical axes 11 and 21 extend. On the other hand, the X direction and the Y direction both indicate normal directions with respect to the optical axes 11 and 21 and are orthogonal to each other. Furthermore, the inclination angle in the plane composed of the Y direction and the Z direction, with the Y direction as a reference (the inclination angle is 0 °), that is, the direction parallel to the Y direction is 0 ° and is parallel to the Z direction. When the direction is 90 °, the tilt angle in the Z direction with respect to the Y direction is θ (where 0 ° ≦ θ ≦ 90 °).

  The lens 10 has inclined portions 12 and 13. The inclined portions 12 and 13 are portions of the lens 10 where the inclination angle θ in the Z direction with respect to the Y direction is 10 ° or more between the optical axes 11 and 21, that is, within the width of the pitch 50 here. Then, it is a part substantially equal to the effective aperture of the lens 10 within the same range. In the wafer 40, the inclined portion 12 is formed on one surface, and the inclined portion 13 is formed on the other surface.

  The lens 20 has inclined portions 22 and 23. The inclined portions 22 and 23 are portions of the lens 20 where the inclination angle θ in the Z direction with respect to the Y direction is 10 ° or more between the optical axes 11 and 21, that is, within the width of the pitch 50 here. Then, it is a part substantially equal to the effective aperture of the lens 20 within the same range. In the wafer 40, the inclined portion 22 is formed on the same side as the inclined portion 12, and the inclined portion 23 is formed on the same side as the inclined portion 13.

  Further, the lens array 100 includes flat portions 32 and 33 between the lens 10 and the lens 20. The flat portions 32 and 33 are lenses having an inclination angle θ in the Z direction with respect to the Y direction that is less than 10 ° (including 0 °) between the optical axes 11 and 21, that is, within the width of the pitch 50 here. This is a portion of the array 100, and here, it is a substantially equal portion between the effective aperture of the lens 10 and the effective aperture of the lens 20 within the same range. In the wafer 40, the flat portion 32 is formed on the same side as the inclined portions 12 and 22, and the flat portion 33 is formed on the same side as the inclined portions 13 and 23.

  Of the dimensions of the adjacent lenses 10 and 20 that occupy the width of the pitch 50 parallel to the Y direction, the width of the inclined portion 12 is the width of the inclined portion 12 as the width 14 of the inclined portion. Is the width 15 of the inclined portion, the width of the inclined portion 22 is the width 24 of the inclined portion, the width of the inclined portion 23 is the width 25 of the inclined portion, the width of the flat portion 32 is the width 34 of the flat portion, and the flat portion 33. Are shown as the width 35 of the flat portion.

  The lens array 100 satisfies the following relational expression (1) regarding the lenses 10 and 20.

Flat part width 35 ≦ slope part width 15 + slope part width 25 (1)
When the wafer array 40 is molded into the lens array 100, the inventors of the present application increase the stress generated in the Y direction as the tilt angle θ in the Z direction with respect to the Y direction increases. As a result of finding that the degree to which the shrinkage in the direction is restricted increases, the present invention has been devised.

  More specifically, the wafer 40 is pressed in the Z direction by, for example, a mold (not shown) when molding the lens array 100. At this time, in the wafer 40, a stress against the pressurization from the mold is generated in the Z direction, and the shrinkage in the Z direction during molding is suppressed by this stress. In order to similarly generate this shrinkage suppression effect using the pressurization in the Z direction in the Y direction, the inclined portions 12, 13, 22, and 23 inclined in the Z direction with respect to the Y direction are provided. It is effective to mold the formed lens array 100.

  The portion of the lens array 100 whose position in the Y direction is equal to the inclined portions 12 and / or 13 becomes the constraining region 16. In this constrained region 16, since the pressure is further increased in the Y direction by the pressurization in the Z direction, the stress is also generated in the Y direction, and the effect of suppressing shrinkage is great. Similarly, the portion of the lens array 100 whose position in the Y direction is equal to the inclined portions 22 and / or 23 becomes the constraining region 26. In this constrained region 26, since the pressure is further increased in the Y direction by the pressurization in the Z direction, the stress is also generated in the Y direction, and the effect of suppressing shrinkage is great. On the other hand, the portion of the lens array 100 whose position in the Y direction is different from any of the inclined portions 12, 13, 22, and 23 becomes the unconstrained region 36. In this unconstrained region 36, there is almost no pressurization in the Y direction due to pressurization in the Z direction, and the stress is not generated in the Y direction, so the effect of suppressing shrinkage is small or almost ineffective.

  According to the above configuration, the flat portion 33 is difficult to generate a large stress in the Y direction between the optical axis 11 of the lens 10 and the optical axis 21 of the lens 20, and a large stress is applied in the Y direction. It is made shorter than the sum of the widths of the inclined portions 13 and 23 that can be generated. This makes it possible to narrow the non-restraining region 36 that is less affected by the stress (restriction of contraction) due to the stress in the Y direction, while widening the restraining regions 16 and 26 that are more affected by the stress. As a result, since the degree of shrinkage in the Y direction of the lens array 100 is reduced, the fluctuation range of the pitch error in the pitch 50 between the molded lenses 10 and 20 can be reduced.

  Accordingly, in the lens array 100, the pitch error (the pitch variation between the lenses) can be satisfactorily suppressed.

  In the lens array 100 shown in FIG. 1, the following relational expression (2) may naturally be satisfied for the lenses 10 and 20.

Flat part width 34 ≦ inclined part width 14 + inclined part width 24 (2)
Further, when the relational expression (2) is satisfied, it is not essential that the relational expression (1) is satisfied.

  From the above, in the lens array 100 shown in FIG. 1, it is sufficient if the lenses 10 and 20 satisfy at least one of the relational expressions (1) and (2). That is, with respect to at least one surface (at least one of the front surface and the back surface) of the wafer 40, the width of the flat portion is less than or equal to the width of the inclined portion between the optical axes 11 and 21 (within the width of the pitch 50). Means that is sufficient.

  When the lenses 10 and 20 have substantially the same shape, the relationship between the lens 10 and the lens 20 is the dimension in the Y direction of one lens when the relational expressions (1) and / or (2) are satisfied. The pitch 50 is a length less than the dimension of the two lenses in the Y direction.

  From the viewpoint of generating a stress large enough to restrict shrinkage, the inclined portion preferably has an inclination angle θ with respect to the Y direction of 10 ° or more, but is not limited to this, and what size is it? In consideration of whether the stress should be generated, it is possible to arbitrarily change the range of the inclination angle.

  From the viewpoint of sufficiently and easily narrowing the region corresponding to the flat portion, the flat portion preferably has an inclination angle θ with respect to the Y direction of less than 10 °. In view of the width of the corresponding area, it is possible to arbitrarily change the range of the inclination angle.

  In addition, the lens array 100 is preferably one in which the variation in PV value is optimized in the lenses 10 and 20 and other molded lenses. Here, the PV value indicates surface accuracy (shape accuracy). In particular, in the present application, the maximum error of the shape of the optical surface of each lens with respect to the design value is indicated. By preparing the lens array 100 by optimizing the PV value in advance, the lens array 100 can achieve sufficiently fine shape accuracy. In particular, the variation in the PV value is preferably within 0.5 μm, whereby the lens array 100 having a very high quality in terms of shape accuracy can be realized.

  In the above description, for the sake of convenience, the normal direction with respect to the optical axes 11 and 21 extending in the Z direction has been assumed to be the Y direction. However, when the normal direction is assumed to be the X direction, or the X direction Even when the normal direction other than the Y direction is assumed, the present invention can be operated in the same manner.

  Both lenses 10 and 20 may be replaced with other optical elements having an optical axis.

[Configuration 2 of optical element array of the present invention]
FIG. 2 is a cross-sectional view showing a configuration of a lens array according to another embodiment of the present invention.

  A lens array (optical element array) 200 shown in FIG. 2 is obtained by molding a plurality of lenses (optical elements) on the same surface of a wafer 140. For the sake of convenience, FIG. 2 shows only two specific adjacent lenses (optical elements) 110 and 120 among the plurality of lenses.

  The lenses 110 and 120 are formed in a direction normal to the optical axis (reference optical axis) 111 of the lens 110 and spaced apart from each other at a predetermined pitch of 150. In particular, in FIG. 2, since the optical axis 121 of the lens 120 is parallel to the optical axis 111, the lenses 110 and 120 have a predetermined pitch 150 with respect to each other in the normal direction to the optical axis 121 of the lens 120. It can also be interpreted as being molded at intervals. In other words, the lenses 110 and 120 are formed so as to be separated from each other at a predetermined pitch of 150 in the normal direction with respect to one of the optical axes 111 and 121.

  In FIG. 2, the Z direction indicates the direction in which the optical axes 111 and 121 extend. On the other hand, the X direction and the Y direction both indicate normal directions with respect to the optical axes 111 and 121 and are orthogonal to each other. Furthermore, the inclination angle in the plane composed of the Y direction and the Z direction, with the Y direction as a reference (the inclination angle is 0 °), that is, the direction parallel to the Y direction is 0 ° and is parallel to the Z direction. When the direction is 90 °, the tilt angle in the Z direction with respect to the Y direction is θ (where 0 ° ≦ θ ≦ 90 °).

  Furthermore, a protrusion (unevenness) 130 is formed between the lenses formed on the wafer 140, for example, between the lens 110 and the lens 120. The protrusion 130 is formed in a portion corresponding to the outer peripheral portion of both effective apertures of the lenses 110 and 120 and corresponding to the flat portion 32 (see FIG. 1) of the lens array 100. Further, the protrusion 130 protrudes in the Z direction parallel to the optical axis 111, and more preferably, as shown in FIG. 2, the side surface thereof is inclined by 10 ° or more in the Z direction with respect to the Y direction. Yes.

  The lens 110 has inclined portions 112 and 113. The inclined portions 112 and 113 include a lens 110 portion where the inclination angle θ in the Z direction with respect to the Y direction is 10 ° or more between the optical axes 111 and 121, that is, within the width of the pitch 150 here. Then, the effective aperture of the lens 110 within the same range is included. Further, in FIG. 2, the side surface of the protruding portion 130 is inclined by 10 ° or more in the Z direction with respect to the Y direction, and the side surface on the lens 110 side of the protruding portion 130 within the same range is included in the inclined portion 112. It is. In the wafer 140, the inclined portion 112 is formed on one surface, and the inclined portion 113 is formed on the other surface.

  The lens 120 has inclined portions 122 and 123. The inclined portions 122 and 123 include a lens 120 portion where the inclination angle θ in the Z direction with respect to the Y direction is 10 ° or more between the optical axes 111 and 121, that is, within the width of the pitch 150 here. Then, the effective aperture of the lens 120 within the same range is included. Further, in FIG. 2, the side surface of the protruding portion 130 is inclined by 10 ° or more in the Z direction with respect to the Y direction, and the side surface on the lens 120 side of the protruding portion 130 within the same range is included in the inclined portion 122. It is. In the wafer 140, the inclined portion 122 is formed on the same side surface as the inclined portion 112, and the inclined portion 123 is formed on the same side surface as the inclined portion 113.

  Further, the lens array 200 has flat portions 132 and 133 between the lens 110 and the lens 120. The flat portions 132 and 133 are lenses in which the inclination angle θ in the Z direction with respect to the Y direction is less than 10 ° (including 0 °) between the optical axes 111 and 121, that is, within the width of the pitch 150 here. Array 200 portion. The flat portion 133 is a substantially equal portion between the effective aperture of the lens 110 and the effective aperture of the lens 120 within the same range, while the flat portion 132 is the same as that of the protrusion 130 within the same range. It is a substantially equal portion between the side surface on the lens 110 side and the side surface on the lens 120 side of the protrusion 130. As a result, the flat portion 132 is narrower than the flat portion 32 (see FIG. 1) of the lens array 100. In the wafer 140, the flat portion 132 is formed on the same surface as the inclined portions 112 and 122, and the flat portion 133 is formed on the same surface as the inclined portions 113 and 123.

  Of the dimensions of the adjacent lenses 110 and 120 that occupy the width of the pitch 150 that is parallel to the Y direction, the width of the inclined portion 112 is the width of the inclined portion 113 as the width 114 of the inclined portion. Is the width 115 of the inclined portion, the width of the inclined portion 122 is the width 124 of the inclined portion, the width of the inclined portion 123 is the width 125 of the inclined portion, the width of the flat portion 132 is the width 134 of the flat portion, and the flat portion 133. Are shown as the width 135 of the flat portion.

  The lens array 200 satisfies the following relational expressions (3) and (4) with respect to the lenses 110 and 120.

Flat part width 134 ≤ inclined part width 114 + inclined part width 124 (3)
Width of flat part 135 ≦ width of inclined part 115 + width of inclined part 125 (4)
The lens array 200 has the same functions and effects as the lens array 100.

  Further, the lens array 200 is different from the lens array 100 in that the protruding portion 130 is formed. The effects obtained by forming the protruding portion 130 in this way are as follows.

  That is, the first effect obtained by forming the protruding portion 130 is that the side surface of the protruding portion 130 protruding in the Z direction is inclined in the Z direction with respect to the Y direction. It can be used as an inclined part according to the above. For this reason, the constraining region 116, which is the lens array 200 portion whose position in the Y direction is equal to the inclined portions 112 and / or 113, can be made wider than the constraining region 16 (see FIG. 1). Similarly, the constraining region 126, which is the lens array 200 portion whose position in the Y direction is equal to the inclined portions 122 and / or 123, can be made wider than the constraining region 26 (see FIG. 1). On the other hand, the unconstrained region 136, which is the lens array 200 portion whose position in the Y direction is different from any of the inclined portions 112, 113, 122, and 123, should be narrower than the unconstrained region 36 (see FIG. 1). Can do. Accordingly, it is apparent that the lens array 200 can suppress the above-described pitch error (pitch variation between the lenses) better than the lens array 100. In addition, the first effect is that even when a depression (not shown) that is depressed in the Z direction is formed instead of the protruding protrusion 130, the side surface of the depression is in the Y direction. However, if it is inclined in the Z direction, the same effect can be obtained.

  The second effect obtained by forming the protruding portion 130 is that the protruding portion 130 of the lens is brought into contact with another member so that the distance between the effective aperture of the lens and the other member is increased. It can be applied to adjust. Details of this will be described later.

  In the lens array 200 shown in FIG. 2, it is sufficient that the lenses 110 and 120 satisfy at least one of the relational expressions (3) and (4). That is, with respect to at least one surface of the wafer 140 (at least one of the front surface and the back surface), the width of the flat portion is less than or equal to the width of the inclined portion between the optical axes 111 and 121 (within the width of the pitch 150). Means that is sufficient.

  When the lenses 110 and 120 have substantially the same shape, the relationship between the lens 110 and the lens 120 is the dimension in the Y direction of one lens when the relational expressions (3) and / or (4) are satisfied. The pitch 150 is less than the dimension in the Y direction of the two lenses.

  Similar to the embodiment of the lens array 100, in the lens array 200, the inclined portion has an inclination angle θ with respect to the Y direction of 10 ° or more, and the flat portion has an inclination angle θ with respect to the Y direction of 10 °. In addition to being less than 0 °, it is possible to arbitrarily change the range of the inclination angle.

  Similar to the embodiment relating to the lens array 100, in the lens array 200, the variation of the PV value is optimized within, for example, 0.5 μm in the lenses 110 and 120 and other molded lenses. Preferably there is.

  In the above description, for the sake of convenience, the normal direction with respect to the optical axes 111 and 121 extending in the Z direction is assumed to be the Y direction. However, when the normal direction is assumed to be the X direction, or the X direction Even when the normal direction other than the Y direction is assumed, the present invention can be operated in the same manner.

  Both lenses 110 and 120 may be replaced with other optical elements having an optical axis.

[Configuration 1 of optical element unit of the present invention]
FIG. 3 is a cross-sectional view illustrating a configuration of an imaging lens according to an embodiment of the present invention.

  The imaging lens (optical element unit) 300 shown in FIG. 3 includes an aperture stop 301 and lenses (optical elements) 302 and 303, respectively.

  Specifically, the aperture stop 301 is provided so as to surround the surface of the lens 302 to be directed to the object (not shown) side. The aperture stop 301 is provided for the purpose of limiting the diameter of the on-axis beam bundle of the incident light so that the light incident on the imaging lens 300 appropriately passes through the lenses 302 and 303.

  A lens (second optical element) 302 indicates one of a plurality of lenses formed on the lens array 200 (see FIG. 2), and the optical axis 304 and a protrusion formed on the outer peripheral portion of the effective aperture. 307. That is, the optical axis 304 is a member corresponding to the optical axis 111, and the protrusion 307 is a member corresponding to the protrusion 130.

  A lens (first optical element) 303 indicates one of a plurality of lenses formed in the lens array 201, and has an optical axis 305. The lens array 201 has the same characteristics as the lens array 100 or 200, although the pitch between the lenses is equal to the pitch between the lenses in the lens array 200 and the shape of the inclined portion is different. It is an optical element array of invention.

  After the lens array 200 and the lens array 201 are bonded together so that the optical axis 304 of the lens 302 and the optical axis 305 of the lens 303 are positioned on the same straight line 306, one imaging lens 300 is This is obtained as a result of dividing by the dividing line 308 for each imaging lens 300, that is, for each combination of the lenses 302 and 303. This process until obtaining one imaging lens 300 corresponds to a wafer level lens process.

  In the imaging lens 300, the protruding portion 307 is in contact with the aperture stop 301 in the direction of the straight line 306 in which the optical axis 304 extends, whereby the distance between the effective aperture of the lens 302 and the aperture stop 301 in the direction of the straight line 306. Has been determined. By making the aperture stop 301 abut on the projecting portion 307 and adjusting the distance between the effective aperture of the lens 302 and the aperture stop 301 in the direction of the straight line 306, the distance can be easily adjusted. .

  Although not shown, a protrusion similar to the protrusion 307 is formed on the outer peripheral portion of the effective aperture with respect to the lens 303, and the protrusion is the lens 302 in the direction of the straight line 306 along which the optical axis 305 extends. The distance between the effective aperture of the lens 303 and the effective aperture of the lens 302 in the direction of the straight line 306 may be adjusted. The distance can be easily adjusted by bringing the lens 302 into contact with the protruding portion of the lens 303 and adjusting the distance between the effective aperture of the lens 303 and the effective aperture of the lens 302 in the direction of the straight line 306. It becomes possible.

  Of course, the lens array 200 may be replaced with the lens array 100. However, when the lens array 200 is replaced, since there is no protrusion in the lens array 100, the effective aperture of the lens 302 and the aperture stop 301 in the direction of the straight line 306 are used. The interval needs to be adjusted separately.

[Configuration of Optical Element Array Mold of the Present Invention]
FIG. 4 shows an example of a method for manufacturing an imaging module using the lens array of the present invention, and is a cross-sectional view showing a process of forming a wafer 140 into the lens array 200.

  Molding of the wafer 140 into the lens array 200 can be performed using molds (optical element array molds) 400 and 400.

  The molds 400 and 400 sandwich the wafer 140 on both sides facing each other, and mold the wafer 140 into the lens array 200. The molds 400 and 400 have inclined molding portions 412 and 422 and a flat molding portion 432 on one of the opposing surfaces, and inclined molding portions 413 and 423 and a flat molding portion on the other of the opposing surfaces. 433, respectively.

  The inclined molding part 412 is a mold part for molding the wafer 140 into the inclined part 112 of the lens array 200, and has a shape opposite to that of the inclined part 112.

  The inclined molding part 413 is a mold part for molding the wafer 140 into the inclined part 113 of the lens array 200, and has a shape opposite to that of the inclined part 113.

  The inclined molding part 422 is a mold part for molding the wafer 140 into the inclined part 122 of the lens array 200, and has a shape opposite to that of the inclined part 122.

  The inclined molding part 423 is a mold part that molds the wafer 140 into the inclined part 123 of the lens array 200, and has a shape opposite to that of the inclined part 123.

  The flat molding portion 432 is a molding die portion that molds the wafer 140 into the flat portion 132 of the lens array 200, and has a shape opposite to that of the flat portion 132.

  The flat molding part 433 is a mold part that molds the wafer 140 into the flat part 133 of the lens array 200, and has a shape opposite to that of the flat part 133.

  Of the dimensions of the adjacent lenses 110 and 120 that occupy the width of the pitch 150 that is parallel to the Y direction, the width of the inclined molding portion 412 is the width 414 of the inclined molding portion. The width of 413 is the width 415 of the inclined forming portion, the width of the inclined forming portion 422 is the width 424 of the inclined forming portion, the width of the inclined forming portion 423 is the width 425 of the inclined forming portion, and the width of the flat forming portion 432 is flat. As the width 434 of the molding part, the width of the flat molding part 433 is shown as the width 435 of the flat molding part.

  Therefore, with respect to the molding parts of the molds 400 and 400 corresponding to the lenses 110 and 120, in the molding part of the molds 400 and 400 that mold the lens array 200 part within the width of the pitch 150, the relational expression described above is used. According to the satisfaction of (3) and (4), the following relational expressions (5) and (6) are satisfied.

Width of flat molded portion 434 ≦ width 414 of inclined molded portion + width 424 of inclined molded portion 424 (5)
Width of flat molded portion 435 ≦ width 415 of inclined molded portion + width 425 of inclined molded portion 425 (6)
According to said structure, it becomes possible to shape | mold the lens array 200 in which the pitch error (pitch variation between each lens) was suppressed favorably using the metal mold | die 400 * 400.

  In the molds 400 and 400 shown in FIG. 4, it is sufficient that the molded parts corresponding to the lenses 110 and 120 satisfy at least one of the relational expressions (5) and (6). That is, regarding the at least one surface (at least one of the front surface and the back surface) of the wafer 140, it is sufficient that the width of the flat formed portion is equal to or less than the width of the inclined formed portion within the width of the pitch 150. It means that. This is sufficient if the width of the flat molded portion is equal to or smaller than the width of the inclined molded portion within the width corresponding to the pitch 150 with respect to at least one of the opposing surfaces of the molds 400 and 400. It means that there is.

  In FIG. 4, the molds 400 and 400 for molding the lens array 200 are illustrated as an example of the optical element array molding die of the present invention. However, the concave portion corresponding to the flat molding portion 432 is omitted, and the lens 110 is omitted. The mold for forming the lens array 100 is made flat by flattening the inclined molded portion 412 portion having a shape opposite to the effective diameter of the lens 120 and the inclined molded portion 422 portion having the shape opposite to the effective diameter of the lens 120. A mold (optical element array mold) can also be easily manufactured.

[Configuration 2 of optical element unit of the present invention, and manufacturing method thereof]
FIG. 5 shows an example of a method for manufacturing an imaging module using the lens array of the present invention, and is a cross-sectional view showing a process of bonding a plurality of lens arrays.

  FIG. 6 shows an example of a method for manufacturing an imaging module using the lens array of the present invention, and is a cross-sectional view showing a process of cutting a plurality of bonded lens arrays for each imaging module.

  FIG. 7 is a cross-sectional view showing the configuration of the imaging module completed through the steps shown in FIGS. 4 to 6.

  From here, with reference to FIGS. 4-7, the method to manufacture the imaging module (optical element unit) 500 by a wafer level lens process is demonstrated.

  In the process shown in FIG. 4, the wafer 140 is sandwiched in the Z direction (see FIG. 2) using the molds 400 and 400 in which the surfaces to be molded are arranged to face each other, and are molded into the lens array 200. Although not shown, in the same step, the wafer is sandwiched in the Z direction using another mold in which the surfaces to be molded face each other and are molded into the lens array 201.

  5 and 6, the lens array 200 and the lens array 201 are bonded together. The lens array 200 and the lens array 201 are bonded so that the optical axis 304 of the lens 302 and the optical axis 305 of the lens 303 are positioned on a straight line 306. In the same process, the aperture stop 301 is provided in contact with the protruding portion 307 of the lens array 200 in order to adjust the distance between the aperture stop 301 and the effective aperture of the lens 302 in the direction of the straight line 306. Further, in the same process, a sensor array 309 having a plurality of sensors 504 (see FIG. 7) formed on the same surface is bonded to the lens array 201. The sensor array 309 is bonded so that one sensor 504 is mounted per lens 303, for example, so that the center of the sensor 504 is positioned on the corresponding straight line 306.

  In the step shown in FIG. 6, what is obtained through the above steps is divided by the dividing line 308 for each imaging module 500, that is, for each combination of the lenses 302 and 303.

  The imaging module 500 completed through the steps shown in FIGS. 4 to 6 includes an aperture stop 501, a lens 502, a lens 503, and a sensor 504, as shown in FIG. The aperture stop 501, the lens 502, the lens 503, and the sensor 504 include the aperture stop 301, the lens array 200 that includes the lens 302, the lens array 201 that includes the lens 303, and the sensors 504 that are included in the sensor array 309, respectively. These are divided for each individual imaging module 500.

  In the imaging module 500, the sensor 504 is provided for the purpose of receiving the formed image as light, and examples thereof include solid-state imaging devices represented by CCD and CMOS.

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

  The present invention relates to an optical element array in which a plurality of optical elements are molded on the same surface of a wafer made of a molded object such as resin, an optical element array mold used for molding the optical element array, and the optical element array. It can utilize for the optical element unit manufactured using the optical element shape | molded in this.

10, 20 Lens (optical element)
11 Optical axis (reference optical axis)
21 Optical axes 12, 13, 22, 23 Inclined portions 14, 15, 24, 25 Inclined portion widths 32, 33 Flat portions 34, 35 Flat portions width 40 Wafer 50 Pitch 100 Lens array (optical element array)
110, 120 lens (optical element)
111 optical axis (reference optical axis)
121 Optical axis 112, 113, 122, 123 Inclined part 114, 115, 124, 125 Inclined part width 130 Protruding part (unevenness)
132, 133 Flat part 134, 135 Flat part width 140 Wafer 150 Pitch 200 Lens array (optical element array)
201 Lens array (optical element array)
300 Imaging lens (optical element unit)
301 Aperture stop 302 Lens (second optical element)
303 Lens (first optical element)
304, 305 Optical axis 306 Straight line (same straight line)
307 Protruding part (unevenness)
400 mold (optical element array mold)
412, 413, 422, 423 Inclined forming portions 414, 415, 424, 425 Inclined forming portion widths 432, 433 Flat forming portions 434, 435 Flat forming portion width 500 Imaging module (optical element unit)
501 Aperture stop 502, 503 Lens 504 Sensor

Claims (6)

A plurality of optical elements are molded on the same surface,
Two adjacent optical elements in the plurality of optical elements are optical element arrays formed by being spaced apart in a direction normal to a reference optical axis that is an optical axis of any one of the optical elements,
A protrusion extending in the direction of the reference optical axis is formed between the two adjacent optical elements,
It is a part excluding the optical element, the side surface of the protrusion, and the region between the optical element and the protrusion, and the inclination with respect to the normal direction is less than 10 ° or the inclination angle is 0 ° A flat part,
All of the optical elements, the side surface of the protrusion region between the optical element and the projecting portion, and an inclined portion inclined obliquely with respect to the normal direction is made from the portion at 10 ° or more, a surface And on the back,
In the front and back surfaces of at least one hand, between the optical axis of the two adjacent optical elements, the width of the flat portion, Ri width der following the inclined portion,
The optical element array , wherein a side surface of the protruding portion has an inclination of 10 ° or more with respect to the normal direction . An optical element array mold for sandwiching a wafer between opposite sides and molding the wafer into an optical element array according to claim 1 ,
A flat molding part for molding the wafer into the flat part between the optical axes of the two adjacent optical elements;
An inclined molding part that molds the wafer into the inclined part between the optical axes of the two adjacent optical elements;
The optical element array mold according to claim 1, wherein a width of the flat molding portion is equal to or less than a width of the inclined molding portion on at least one of the two surfaces. Using a plurality of optical element arrays according to claim 1 ,
After pasting each optical element array so that the optical axes of one optical element respectively molded in each optical element array are located on the same straight line,
An optical element unit obtained as a result of dividing a combination of optical elements whose optical axes are located on the same straight line as a unit. The first optical element is one of the combination is the protrusion formed on the outer peripheral portion of the effective aperture,
4. The optical device according to claim 3 , wherein the protruding portion of the first optical element and the second optical element which is the other of the combinations are in contact with each other in the optical axis direction of the first optical element. Element unit. An aperture stop,
The second optical element is the protruding portions on the outer peripheral portion of the effective aperture is formed,
The optical element unit according to claim 4 , wherein the protruding portion of the second optical element and the aperture stop are in contact with each other in the optical axis direction of the second optical element. An aperture stop,
At least one of the optical elements is the protrusion at the periphery of the effective aperture is formed,
The optical element unit according to claim 3 , wherein the projecting portion of the optical element and the aperture stop are in contact with each other in the optical axis direction of the optical element.

Images