Abstract:
Provided are a wafer lens and a wafer lens manufacturing method which makes it possible to favorably manage lens inspection information. The wafer lens is formed by laying a diaphragm and an ID recording section on a glass substrate and covering the diaphragm and the ID recording section with a resin layer which forms optical members, the ID recording section having individual identification information (a wafer ID) of the wafer lens recorded therein. Further, the wafer lens manufacturing method comprises: an inspection step of inspecting optical components structured in the wafer lens; an identification information reading step of reading the wafer ID from the ID recording section; and a storage step of storing, in a management server, inspection information obtained in the inspection step while associating the inspection information with the wafer ID of the inspected wafer lens and further with component IDs thereof.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a wafer lens and wafer lens manufacturing method. 
         [0002]    Conventionally in the optical lens manufacturing field, a study has been made to develop a technique of manufacturing an optical lens having a high heat resistance by installing on a glass plate a lens section (optical member) made of curable resin such as a photo-curable resin (see Patent Literature 1, for example). 
         [0003]    In one of the optical lens manufacturing methods based on this technique, a diaphragm made of metallic film for adjusting the amount of incoming light is formed on the surface of a glass plate, and a plurality of optical members made of curable resin are laid on the surface of the diaphragm, so that a so-called “wafer lens” is produced. After that, a plurality of lenses are integrally formed and are laminated and bonded by holding a space in-between or abutting on a projection formed simultaneously with the optical surface, so that a plurality of lens sets are formed. After that, the glass plate is cut. This manufacturing method cuts off the optical lens manufacturing cost. Further, the aforementioned wafer and a plurality of lens sets are cut into separate pieces, which are further mounted on an image sensor. Further, the sensor formed similarly in a wafer is combined with a wafer lens and a plurality of lens sets and is then cut off into separate pieces. Thus, high-volume production of compact, high-resolution image capturing units including a sensor can be achieved. Industrial attention is being directed to this technique. 
         [0004]    Normally, a resist pattern is formed on the surface of the glass plate by photolithography. After that, a diaphragm is formed on the glass plate by repeating the processes of etching, vapor deposition and plating. However, this method includes a great number of steps, and is required to be more simplified. 
         [0005]    To simplify the manufacturing step in the formation of a diaphragm, the present applicants proposed a wafer lens manufacturing method in the Japanese Patent Application No. 2008-116639 wherein one surface of a substrate is coated with a photoresist including carbon black and the photoresist is then developed by exposition to light, so that a diaphragm having a prescribed pattern is formed. 
       EARLIER TECHNOLOGICAL LITERATURE 
     Patent Literature 
       [0000]    
       
         Patent Literature Japanese Examined Patent Application Publication No. 3926380 
       
     
       SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
       [0007]    Incidentally, before being separated into individual lens units, a wafer lens is subjected to various processes up to inspection as a single wafer or as an assembled wafer set composed of a plurality of wafers assembled into one piece. This is intended to improve the manufacturing efficiency. 
         [0008]    This method has a problem that, since lenses having been inspected are each held integrally by a wafer lens, assorting management for each lens—e.g., removing faulty lenses based on the inspection result—cannot be made. 
         [0009]    In view of the problems described above, it is an object of the present invention to provide a method for manufacturing a wafer lens wherein the occurrence of faulty lens is minimized by an effective use of inspection information obtained in the step of inspection, and a method for manufacturing a wafer lens suitable for managing individual information such as lens inspection information, and a wafer lens capable of ensuring an effective management of lens inspection information. 
       Means for Solving the Problems 
       [0010]    To achieve the above-mentioned object, a method for manufacturing a wafer lens wherein an optical member made of curable resin is formed on a substrate reflecting one aspect of the present invention includes: a step of measuring the back focus of each lens unit on the wafer; a step of selecting a spacer having an optimum thickness for combination with the wafer based on the measurement result of the back focus; and a step of bonding the wafer to the selected spacer. 
         [0011]    In the aforementioned first aspect, the step of selecting a spacer having an optimum thickness for combination with the wafer based on the measurement result of the back focus preferably includes a step of recording in a data file the information for specifying an optimum spacer to be selected, and the information for identifying the non-conforming lens units when the optimum spacer has been selected. 
         [0012]    A wafer lens with the optical member made of curable resin formed on a substrate reflecting the second aspect of the present invention includes a diaphragm as an optical component and an identification information recording section for recording the individual identification information of the wafer mounted on the substrate, wherein the diaphragm and identification information recording section are covered with a resin layer for forming the aforementioned optical component. 
         [0013]    In the aforementioned second aspect, the aforementioned diaphragm and the identification information recording section are preferably formed of the same material arranged on the same layer. 
         [0014]    The aforementioned same material is more preferably made of a lightproof photoresist. 
         [0015]    A wafer lens manufacturing method reflecting the third aspect of the present invention includes: 
         [0016]    1) a lamination step for laminating the layer of the same material constituting a diaphragm as an optical component and an identification information recording section for recording the individual identification information of the wafer lens, on the substrate; 
         [0017]    2) a patterning step of forming the diaphragm by selectively removing the layer of the same material by patterning; 
         [0018]    3) an identification information recording step for forming the identification information recording section by selectively processing the layer of the same material by a laser marker; 
         [0019]    4) a molding step of filling a curable resin between the surface of the substrate having the diaphragm and the identification information recording section formed thereon, and a molding die, forming an optical member by the molding die using a curable resin as a material, and coating the diaphragm and the identification information recording section with the curable resin, and 
         [0020]    5) a curing step of curing the curable resin. 
         [0021]    In the aforementioned third aspect, it is preferred that a layer of lightproof photoresist should be used as the layer of the same material in the lamination step, and the layer of lightproof photoresist should be selectively removed in the identification information recording section subsequent to exposure and development of the layer of lightproof photoresist in the patterning step, so that the identification information recording section is formed 
         [0022]    The aforementioned third aspect preferably includes: an inspection step of inspecting the optical member formed on a wafer lens subsequent to the curing process; an identification information reading step for reading the individual identification information of a wafer lens from the identification information recording section; and a storage step of storing in a management server inspection information obtained in the inspection step by associating the inspection information obtained from the inspection step with the individual identification information of the wafer lens to be inspected. 
         [0023]    Further, the aforementioned third aspect preferably includes a storage step of presetting the component identification information for identifying the individual optical member for each area for forming the optical member on a wafer lens, and associating the inspection information on each optical member obtained in the inspection step with the individual identification information on the wafer lens to which the optical member to be inspected belong, and the component identification information on the optical member to be inspected, so that this inspection information is stored in a management server. 
         [0024]    Further, the aforementioned third aspect preferably includes a display step wherein a surface map of a wafer lens is displayed on an image display device, and the inspection information of the optical member is displayed on the position corresponding to the region for forming the optical member to be inspected on the surface map, based on the individual identification information, component identification information and inspection information associated with them. 
         [0025]    Further, the aforementioned third aspect preferably includes an inspection failure recording step wherein a laser marker is used to selectively process the optical member to be determined as having failed in the inspection, based on the inspection information after the inspection step, and a visual display is formed to indicate that this optical member has failed in the inspection. 
       Effects of the Invention 
       [0026]    The wafer lens manufacturing method reflecting the first aspect of the present invention selects, based on the result of measuring the back focus of each lens unit on a wafer, the spacer having the optimum thickness for combination with the wafer. This structure minimizes the occurrence of faulty lenses. 
         [0027]    The wafer lens reflecting the second aspect of the present invention identifies each wafer lens by allowing a reading device to read the individual identification information of the wafer lens from the identification information recording section. This individual identification information is used to ensure effective individual information management. 
         [0028]    A diaphragm as an optical member and an identification information recording section having the individual identification information of the wafer lens recorded thereon are laid on the substrate, and the diaphragm and identification information recording section are covered with the resin layer for forming the optical member. This structure enhances the information storage performance and tampering preventive performance. 
         [0029]    At the same time the coating layer of the identification information recording section is made of the resin layer forming the optical member. This structure ensures protection against an increase in the number of the steps or materials for forming the coating layer of the identification information recording section. 
         [0030]    Further, the diaphragm and identification information recording section are formed of the same material arranged on the same layer. This permits lamination of the constituting layers of the identification information recording section in the same step as that for the lamination of the diaphragm constituting layer. This structure ensures protection against an increase in the number of the steps or materials for laminating the constituting layers of the identification information recording section. 
         [0031]    The manufacturing step can be simplified by using a lightproof photoresist as the constituting material of the diaphragm and identification information recording section, as compared to the method of using the conventional metallic film. 
         [0032]    The wafer lens manufacturing method reflecting the third aspect of the present invention produces a wafer lens having the individual identification information on the wafer lens recorded thereon. This structure provides the same advantages as above, and ensures effective management of the lens inspection information. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0033]      FIG. 1  is a plan view representing ¼ part of a first wafer lens in one embodiment of the present invention; 
           [0034]      FIG. 2  is a cross section (taken along arrow line A-A) of a wafer lens set in one embodiment of the present invention; 
           [0035]      FIG. 3  is a plan view representing ¼ part of a second wafer lens in one embodiment of the present invention; 
           [0036]      FIG. 4  is a block diagram showing the flow of the wafer lens manufacturing method (including the inspection step) in one embodiment of the present invention; 
           [0037]      FIG. 5  is a schematic diagram representing an MTF/FB test instrument in one embodiment of the present invention; 
           [0038]      FIG. 6  is a detailed plan representing a light source of the MTF/FB test instrument in  FIG. 5 ; 
           [0039]      FIG. 7  is a cross sectional view showing a warpage correcting jig in one embodiment of the present invention; 
           [0040]      FIG. 8  is a side view showing a distance sensor with respect to the illustrated wafer lens; 
           [0041]      FIG. 9  is a schematic diagram showing a test instrument for capturing of an undesired image in one embodiment of the present invention; 
           [0042]      FIG. 10  is a map display drawing corresponding to the wafer lens of the inspection information (error data) in one embodiment of the present invention; and 
           [0043]      FIG. 11  is a drawing showing a lens unit mounted on an image pickup element. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0044]    The following describes one embodiment of the present invention with reference to drawings: The following illustrates only one embodiment of the present invention without being restricted thereto. 
         [0045]    Referring to  FIGS. 1 through 3 , the following describes the wafer lens in one embodiment of the present invention. 
         [0046]    The wafer lens of the present invention is intended as the first and second wafer lenses. The first wafer lens L 1  and the second wafer lens L 2  are provided with individual identification information (hereinafter referred to as “wafer ID”. 
         [0047]    As shown in  FIG. 1 , the wafer lens L 1  includes a glass substrate  10 , diaphragm  11   a  and ID recording section  11   b  formed on the surface of the glass substrate  10 . Many diaphragms  11   a ,  11   a ,  11   a , . . . are provided on the large portion at the center of the glass substrate  10 . The ID recording section  11   b  is formed around many diaphragms  11   a ,  11   a ,  11   a, . . . .    
         [0048]    The diaphragms  11   a  and ID recording sections  11   b  are formed of the same material arranged on the same layer  11 . A lightproof photoresist is used in the present embodiment. A photoresist mixed with carbon black is used as a lightproof photoresist 
         [0049]    The ID recording section  11   b  is composed of two-dimensional barcodes. The ID recording section  11   b  includes a record of the information represented in binary notation composed of a specified number of digits. This information contains the wafer ID of the first lens L 1 , and can be read by a barcode reader. 
         [0050]    As shown in  FIG. 2 , the diaphragm  11   a  and ID recording section  11   b  are covered with a photocurable resin layer  12  constituting an optical member  12   a  and others. 
         [0051]    The photocurable resin layer  12  is formed on the surface where the diaphragm  11   a  and ID recording section  11   b  of the glass substrate  10  are formed, and constitutes a convex lens section  12   a , lens peripheral projection  12   b  and peripheral plate  12   c . The diaphragm  11   a  is covered with the convex lens section  12   a , lens peripheral projection  12   b  and others, and the ID recording section  11   b  is covered with the peripheral plate  12   c.    
         [0052]    A resin layer  13  is formed on the side of the glass substrate  10  opposite to the resin layer  12 . The resin layer  13  forms a concave lens section  13   a  at the position coaxial with the convex lens section  12   a.    
         [0053]    The component made of one convex lens section  12   a , one diaphragm  11   a  and one concave lens section  13   a  correspond to one unit of the component, and is unitized with other wafer lens L 2 , spacer  30  and image sensor (not illustrated) in the state being held by wafer. 
         [0054]    As shown in  FIG. 3 , the second wafer lens L 2  is provided with a glass substrate  20 , and a diaphragm  21   a  and ID recording section  21   b  formed flat with the glass substrate  20 . Many diaphragms  21   a ,  21   a ,  21   a , . . . are formed on the greater portion of the center of the glass substrate  20 . An ID recording section  21   b  is formed on the periphery of the many diaphragms  21   a ,  21   a ,  21   a , . . . . The diaphragms  21   a  and ID recording section  21   b  are formed of the same material arranged on the same layer  21 , and a lightproof photoresist is used in the present embodiment. This lightproof photoresist is mixed with carbon black. 
         [0055]    The ID recording section  21   b  is formed of two-dimensional barcodes. The ID recording section  21   b  includes a record of the information represented in binary notation composed of a specified number of digits. This information contains the wafer ID of the second lens L 2 , and can be read by a barcode reader. 
         [0056]    As shown in  FIG. 2 , the diaphragm  21   a  and ID recording section  21   b  are covered with a photocurable resin layer  22  constituting a convex lens  22   a  and others. 
         [0057]    The resin layer  22  is formed on the surface wherein the diaphragm  21   a  and ID recording section  21   b  of the glass substrate  10  are formed, and constitutes the convex lens  22   a , lens peripheral projections  22   b  and  22   c . The diaphragm  21   a  is covered with the convex lens  22   a , lens peripheral projections  22   b  and  22   c , and the ID recording section  21   b  is covered with the lens peripheral projection  22   c.    
         [0058]    A resin layer  23  is formed on the side of the glass substrate  20  opposite to the resin layer  22 . The resin layer  23  forms a concave lens section  23   a  at the position coaxial with the convex lens section  22   a.    
         [0059]    The component made of one convex lens section  22   a , one diaphragm  21   a  and one concave lens section  23   a  correspond to one unit of the component, and is unitized with other wafer lens L 1 , spacer  30  and image sensor (not illustrated) in the state being held by wafer. 
         [0060]    The following describes the method for manufacturing the wafer lens in one embodiment of the present invention with reference to  FIGS. 4 and 5 . 
         [0061]    The same material layer  11  ( 21 ) constituting the diaphragm  11   a  ( 21   a ) as an optical member and ID recording section  11   b  ( 21   b ) with the wafer ID to be recorded thereon is laminated on the glass substrate  10  ( 20 ) (in the laminating step). The photoresist mixed with carbon black is used as the material layer  11 , and is coated on the glass substrate  10 . 
         [0062]    The material layer  11  ( 21 ) is selectively removed by the processing of patterning exposure and subsequent development so that the diaphragm  11   a  ( 21   a ) is formed (patterning process). 
         [0063]    The material layer  11  ( 21 ) left unremoved on the periphery of the diaphragm  11   a  ( 21   a ) is selectively removed by the laser marker LM 1  shown in  FIG. 4 , so that the ID recording section  11   b  ( 21   b ) is formed (equivalent to blocks A 1  and A 2  in the identification information recording step). In this case, formation of the ID recording section is equivalent to recording of the wafer ID. The laser marker LM 1  is controlled by the marker control PC (block MC) and the information on the wafer ID is stored in the marker control PC. The marker control PC controls the laser marker LM 1  and assigned wafer ID to each wafer lens. 
         [0064]    The wafer ID assigned by the marker control PC (block MC) is sent from the marker control PC to a server PC (block S) and a data file for each wafer ID is created by the server PC. The manufacturing information such as the date of manufacture can be recorded on the data file. 
         [0065]    When the data file is created, the server PC sets up the component identification information for identifying the lens on the wafer lens. The component identification information for identifying the lens on the wafer lens is provided in conformity to each lens on the wafer lens. Each lens and component identification information thereof are correlated with each other, depending on the position in the lens forming area. To be more specific, address information is set in each lens forming area and this address information is used as the identification information of the lens to be formed therein. This saves the trouble of providing a product with the component identification information for identification of lenses. 
         [0066]    The inspection information on the lens on the wafer lens identified by this wafer ID is stored in the data file assigned with the wafer ID as the production history information, in the form associated with the address information of the relevant lens. 
         [0067]    After the wafer ID has been assigned, the system goes to the subsequent wafer lens manufacturing step and the step of laminating and combining two wafer lenses, as shown by the block B of  FIG. 4 . 
         [0068]    In the first place, a photocurable resin is filled between the surface of the glass substrate  10  ( 20 ) with the diaphragm  11   a  ( 21   a ) and ID recording section  11   b  ( 21   b ) formed thereon, and the molding die (not illustrated). The optical member (convex lenses  12   a ,  22   a ), lens peripheral projection  12   b  ( 2   b ,  22   c ), and peripheral plate  12   c  are formed by the molding die, using the photocurable resin as material. The diaphragm  11   a  ( 21   a ) and ID recording section  11   b  ( 21   b ) are covered with the curable resin (molding step). In this step, for example, the resin in the state of monomer (prior to curing) is placed on the glass substrate  10  ( 20 ), and the molding die is pressed against the resin from the top. 
         [0069]    Further, the resin is cured by exposure to light (curing step). In this case, light is applied from the side of the glass substrate  10  ( 20 ), or from the molding die which is made of a transparent material such as a transparent resin. 
         [0070]    The resin layer  13  ( 23 ) on the other surface of the glass substrate  10  ( 20 ) is also formed in the similar manner, so that the first wafer L 1  and second wafer L 2  are produced. 
         [0071]    After that, as shown in  FIG. 2 , the surface of the resin layer  13  of the first wafer L 1  and the resin layer  23  of the second wafer L 2  are put together to laminate a dual wafer, which is bonded and fixed until a wafer set (L 1 +L 2 ) is formed. 
         [0072]    This is followed by the step of measuring the back focus BF of each lens unit on the wafer set (L 1 +L 2 ) for the purpose of selecting a spacer  30  having the optimum thickness. 
         [0073]    The FB inspection PC (block C 1 ) controls the FB test instrument and measures the back focus BF of each lens unit on the wafer set (L 1 +L 2 ) sequentially. At the same time, the FB inspection PC (block C 1 ) allows the attached barcode reader to read the wafer ID of the second wafer lens L 2  from the ID recording section  21   b  on the wafer set (L 1 +L 2 ) to be tested. Thus, the ID to be tested is identified. 
         [0074]    The wafer set (L 1 +L 2 ) can be identified either by the wafer ID of the first wafer lens L 1  or by the wafer ID of the second wafer lens L 2 . Use of one of the wafer IDs is sufficient. In the present embodiment, the wafer ID of the second wafer lens L 2  and the data file thereof will be used 
         [0075]    It goes without saying that the wafer ID of the first wafer lens L 1  and the data file thereof are used for the information management of the first wafer lens L 1  as a single body, and the wafer ID of the second wafer lens L 2  and the data file thereof are used for the information management of the second wafer lens L 2  as a single body. 
         [0076]    The FB inspection PC downloads the data file of the corresponding ID from the server PC, and records the inspection information on the data file. Then the information is uploaded on the serve PC so that the server PC updates the data file. 
         [0077]    The inspection information recorded on the data file by the FB inspection PC includes the information for identifying the optimum spacer  30  to be selected, and the information for identifying the lens unit that will be non-conforming when this spacer has been selected (error information Err). 
         [0078]    The following describes the standards of the back focus FB. 
         [0079]      FIG. 11  shows a lens unit mounted on an image pickup element  100  (CMOS sensor, etc.). The lens unit is fixed on the pickup element by bonding the spacer  30  with a cover glass  101  of the image pickup element  100 . 
         [0080]    In this case, due to lack of a focus adjusting mechanism in conformity to the distance of a subject, it is necessary to use a pan focus lens wherein the focus is adjusted from a subject at a long distance to a subject at a short distance. Thus, the focus on an object at a distance of U/2 from an infinitely long distance can be considered to have been adjusted in terms of geometrical optics, by achieving agreement between the image point position of the lens unit and the position of the photoelectric converter  102  of the image pickup element  100  in the optical axial position, at a hyperfocal distance U≈f 2 /(F×2×P) (where f: focal distance of a lens unit, F: F—number of lens unit, P: pixel pitch of image pickup element). I the case of f=3 mm, F=2.8, and P=0.00175 mm, for example, if the thickness of the spacer  30  is set so as to achieve agreement between the image point of the lens unit at a hyperfocal distance U≈3 2 /(2.8×2×0.00175)=918 mm (approximately 92 cm) and the photoelectric converter  102  of the image pickup element in terms of a reference subject range, the focus can be adjusted up to a distance of 46 cm from an infinitely long distance. Further, the reference subject need not always be set at a hyperfocal distance. For example, when a subject at a longer distance is of greater concern, the reference subject distance should be set at a point farther than the hyperfocal distance. To put it more specifically, reduce the thickness of the spacer  30  slightly. 
         [0081]    The focus setting accuracy at a reference range should be kept at a level that does not exceed 0.5 times the focal depth (generally, calculated by ±F×2×P). In the aforementioned example, the focus setting accuracy is preferably kept at a level that does not exceed ±0.5×2.8×2×0.00175=±0.0049 mm. Thus, the thickness of the spacer  30  for setting the optimum focus should be so set as to ensure that the FB of the greatest possible number of the lens units inside the wafer set can be kept within this scope. Accordingly, in terms of the thickness of the spacer to be prepared in advance, several types of spacers having a difference in thickness with a pitch smaller than 0.0049 mm are preferably prepared in the aforementioned case. In an alternative procedure, the FB mean value of the lens unit inside the wafer set is measured. After that, the plate glass is ground to adjust the thickness of the spacer  30  so as to get a desired focal position. 
         [0082]    The standards for the back focus BF are determined as follows: For example, the first step is to find the mean value of the FB of all the lens units inside the wafer set. The measurements kept within the range of FB tolerable variation that has been preset with consideration given to focal depth are considered as conforming to the standards, and the measurements in excess of this range is considered as non-conforming. Inspection information is recorded according to this principle. 
         [0083]    After that, the wafer set (L 1 +L 2 ) is combined with the spacers  30  selected based on the inspection information recorded in the data file of the ID. Then they are laminated as shown in  FIG. 2 , and are bonded and fixed in position. 
         [0084]    This is followed by the step of MTF/FB inspection. 
         [0085]    The MTF/FB inspection PC (block C 2 ) controls the MTF/FB test instrument  4  of  FIG. 5  so that each lens unit on the wafer set (L 1 +L 2 +spacer  30 ) is subjected to the MTF/FB inspection. 
         [0086]    As shown in  FIG. 5 , the MTF/FB test instrument  4  includes a light source  41  for applying a prescribed amount of light to the lens, an automatic XY stage  42  that mounts the wafer lens WL and move the same in the two-axis X-Y direction perpendicular to the direction of irradiation (Z axis), a distance sensor  43  fixed on the light source  41  to measure the distance from the lens, a measuring optical system  44  provided with multiple CCD cameras, and cameras  45  for adjusting the wafer rotation. The light source  41  and distance sensor  43  fixed thereon are controlled in the movement in the vertical direction (Z-axis direction). 
         [0087]    As shown in  FIG. 6 , the light source  41  is provided with a halogen fiber  41   a , band pass filter  41   b , diffusion plate  41   c  and chart  41   d.    
         [0088]    The wafer set (L 1 +L 2 +spacer  30 ) used for the aforementioned manufacturing process is mounted as the wafer lens WL of  FIG. 5 . 
         [0089]    The MTF/FB inspection PC allows one of the CCD cameras of the measuring optical system  44  to measure the value of the MFT (Modulation Transfer Function) at the center of a lens, and moves the light source  41  in the vertical direction to identify the FB that maximizes the MTF value. The MTF/FB inspection PC calculates the FB value based on the output from the distance sensor  43 . Further, the MTF/FB inspection PC uses other four cameras of the measuring optical system  44  to measure the MTF value on the periphery of the lens at the FB value, and calculates the percentage of the MTF value on the periphery of the lens with respect to the maximum value at the center of the lens. 
         [0090]    The MTF/FB inspection PC controls the MTF/FB test instrument  4 , and performs the aforementioned measurement and calculations for each irradiation of different frequencies. Based on the values having been obtained, the MTF/FB inspection PC selects the non-conforming lens unit 
         [0091]    The MTF/FB inspection PC uses the attached barcode reader to read the wafer ID of the second wafer L 2  from the ID recording section  21   b  on the wafer set (L 1 +L 2 +spacer  30 ) and identifies the ID of the object to be tested. 
         [0092]    The MTF/FB inspection PC downloads the data file of the relevant ID from the server PC, and records the inspection information into this data file. This information is then uploaded to the server PC, which updates the data file. 
         [0093]    The inspection information recorded on the data file by the MTF/FB inspection PC includes the information (error information Err) for identifying the non-conforming lens unit. 
         [0094]    The following describes the method for correcting the warping of the wafer lens WL for MTF/FB inspection and image output inspection. If the wafer lens WL to be tested is warped, correct measurements cannot be obtained. Correction of warpage of the wafer lens WL provides an effective means for accurate measurement. 
         [0095]    A warpage correcting jig  5  of  FIG. 7  is used to correct the warpage of the wafer lens WL. The warpage correcting jig  5  includes a frame member  51  having a vent  51   a , and a sealing glass  52  for enclosing one surface of the frame member  51 . 
         [0096]    The wafer lens WL is mounted on the other surface of the frame member  51 . The edge of the wafer lens WL is adjusted to the frame member  51 . They are brought in close contact and are fixed in position. Sealing is provided to protect against air leakage. They can be brought in close contact and sealed by pressing the edge of the wafer lens WL mechanically against the frame member  51 , or by forming a porous vacuum frame at the position wherein the wafer lens WL of the frame member  51  is mounted, so that the wafer lens WL is held in position by suction. Other proper methods can also be used. 
         [0097]    The warpage correcting jig  5  holding the wafer lens WL is mounted on the automatic XY stage  42  of the MTF/FB test instrument  4 . The position of the distance sensor  43  in the Z-axis direction is fixed and the automatic XY stage  42  is moved. The warpage of the wafer lens WL is measured by the distance sensor  43 . Warpage can be measured by other means than the MTF/FB test instrument  4   
         [0098]    Any one of the autocollimator  61  of  FIG. 8 , the contact type displacement meter  62  and other laser trigonometric displacement meters can be used as the distance sensor for the wafer lens. 
         [0099]    If the wafer lens WL is convexed toward the top n  FIG. 7  after measurement of the warping of the wafer lens WL in the aforementioned procedure, air is sucked from the enclosed space  53  by a pneumatic pump through the vent  51   a . If the lens is concaved toward the bottom, air is pressed into the enclosed space  53 , so that the amount of warpage of the wafer lens WL is reduced and the warpage is corrected to a flat level. If the warpage of the wafer lens WL has been corrected, the pressure inside the enclosed space  53  is maintained so as to keep the wafer lens WL in the corrected state. 
         [0100]    Use of the warpage correcting jig  5  allows the wafer lens WL to be measured after the warpage has been removed. 
         [0101]    If the side opposite to the wafer lens WL is sealed by a sealing glass  52 , the sealing glass  52  allows passage of light. This provides an effective means for optical measurement of the wafer lens WL. 
         [0102]    This is followed by the step of image output inspection. 
         [0103]    The image output inspection PC uses the attached barcode reader to read the wafer ID of the second wafer L 2  from the ID recording section  21   b  on the wafer set (L 1 +L 2 +spacer  30 ) and identifies the ID of the object to be tested. The image output inspection PC downloads the data file of the relevant ID from the server PC. By referencing the error information Err, the image output inspection PC identifies the lens units which have been rejected as non-conforming in the MTF/FB inspection at the time of MTF/FB inspection, and excludes such lens units out of the scope of inspection. Then the remaining lens units are subjected to image output inspection. 
         [0104]    The image output inspection PC (block C 3 ) controls an undesired image capturing tester  7  to test the image output performance of the lens unit on the wafer set (L 1 +L 2 +spacer  30 ). 
         [0105]    The undesired image capturing tester  7  is provided with a measuring head  70  integrally containing a CCD  71 , image output board  72  and distance sensor  73 . This measuring head  70  is controlled in the movement in the vertical direction (Z-axis direction). 
         [0106]    Further, the undesired image capturing tester  7  includes an automatic XY stage  74 , uniform light source  75 , and alignment cameras  76 ,  76 . The frame  77  and warpage correcting jig  5  are shared with the MTF/FB test instrument  4 . 
         [0107]    The image output inspection PC (block C 3 ) is provided with a motion controller  81 , D/IO board  82  and image input board  83 . The motion controller  81  is connected to the actuator for the movement of the measuring head  70  through a driver  91 . The motion controller  81  is also connected to the actuator for the movement of the automatic XY stage  74  through a driver  92 . The D/IO board  82  is connected to the uniform light source  75  so that light is outputted from the uniform light source  75 . The image input board  83  is connected to the alignment cameras  76 , so that the captured image of the alignment cameras  76  is loaded inside. The distance sensor  73  is also connected to the image output inspection PC. 
         [0108]    The wafer set (L 1 +L 2 +spacer  30 ) used for the aforementioned manufacturing process is mounted as the wafer lens WL of  FIG. 9 . 
         [0109]    After inspection, the image output inspection PC records the inspection information in the relevant data file, and uploads the information to the server PC, which then updates the data file. 
         [0110]    The inspection information recorded in the data file by the image output inspection PC includes the information (error information Err) for identifying the non-conforming lens unit. 
         [0111]    External inspection is performed by using the external inspection image pickup PC (block C 4 ) and image confirmation is performed by using image confirmation PC (block C 5 ). These inspections can be replaced by the automatic inspection PC (block D) that automates the work to be performed by the inspector. 
         [0112]    These PCs (C 4 , C 5 , D) use the attached barcode reader to read the wafer ID of the second wafer L 2  from the ID recording section  21   b  on the wafer set (L 1 +L 2 +spacer  30 ) to be inspected, and identifies the ID of the object to be tested. These PCs download the data file of the relevant ID from the server PC. By referencing the error information Err having been inspected, these PCs exclude out of the scope of inspection the lens units which have been rejected as non-conforming. All the remaining lens units are inspected or the images thereof are outputted for inspection. These PCs records the inspection information in the relevant data file and upload the information to the server PC, which then updates the data file. 
         [0113]    The inspection information recorded in the data file by these PCs (C 4 , C 5 , D) includes the information (error information Err) for identifying the non-conforming lens unit. 
         [0114]    In the middle or upon termination of the aforementioned inspections, the surface map of the wafer lens is displayed on the image display device in response to the operator&#39;s request or whenever required. Based on the data file identified by the wafer ID of the wafer lens to be tested, the inspection information of the lens unit is displayed in the area wherein the optical component to be tested on the surface map is formed. 
         [0115]    In the present embodiment, as shown in  FIG. 10 , the error information Err of the lens unit recorded on the data file is displayed at the position of the relevant lens unit on the surface map of the wafer lens. 
         [0116]    In  FIG. 10 , “0” indicates the invalid region wherein a lens is not intended to be formed. “1” denotes a normal lens having passed the inspection, “2” shows the lens having been rejected as non-conforming in the MTF/FB inspection, “3” represents the lens having been rejected as non-conforming in the image output inspection and “4” indicates the lens having been rejected as non-conforming in the external inspection. 
         [0117]    Upon termination of all the aforementioned inspections, the optical components to be determined as non-conforming, based on the error information Err recorded in the data file, namely, the lenses marked with “2”, “3” and “4” in  FIG. 10  are provided with processing. Namely, the surface of the convex lens section  22   a  is selectively processed by the laser marker LM 2  so that the surface is marked with a visual representation (e.g., “X”) of a failure in the inspection. Since the convex lens section  22   a  is transparent, marking is preferably provided by processing of discoloration by the laser marker M 2  in this case. 
         [0118]    As shown in  FIG. 2 , the wafer lens assembled and inspected in the aforementioned procedure is cut at the concave portion of the lens peripheral projections  12   b  of adjacent optical members by the blade with a width smaller than that of the concave portion, and is separated into individual lens units. 
         [0119]    As described above, the non-conforming products are marked as such. This permits use of the lens unit after separation by exclusion of the non-conforming products. This has the advantage that inadvertent use of the non-conforming product can be avoided even when another different step is used for assembling with sensor units and other processing subsequent to the step of cutting. 
         [0120]    When the wafer lens assigned with the wafer ID together with the error information Err thereof is supplied to the aforementioned different step, the worker or the manufacturing machine has the advantage of manufacturing the products without being mixed with non-conforming components, by referencing the wafer ID and error information Err having been supplied. 
         [0121]    The above description is based on the assumption that the wafer set composed of a combination of multiple wafer lenses is inspected in the step of inspection. Without the present invention being restricted thereto, a single wafer lens can be inspected in each of the aforementioned inspection steps. The lens unit to be produced can be composed of a single lens, without being restricted to the one composed of a lens set.