WO2016021028A1 - Lens sheet inspection method, lens sheet obtained using same, optical waveguide with lens, and electrical wiring board with lens - Google Patents

Abstract

The present invention is a method for inspecting a lens sheet having a plano-convex lens formed on at least a portion thereof, said lens sheet inspection method having a step A for causing inspection light to enter the plano-convex lens, a step B for measuring at least one of the substantial image light intensity, image size, image shape, and image position β of the inspection light that has passed through the plano-convex lens at a distance α from the bottom surface of the plano-convex lens in the thickness direction of the lens sheet, and a step C for determining the quality of the plano-convex lens from the at least one of the substantial image light intensity, image size, image shape, and image position β.

Description

LENS SHEET INSPECTING METHOD AND LENS SHEET OBTAINED BY THE METHOD, OPTICAL WAVEGUIDE WITH LENS, AND ELECTRIC WIRING BOARD WITH LENS

The present invention relates to a method for inspecting a lens sheet, a lens sheet obtained thereby, an optical waveguide with a lens, and an electric wiring board with a lens.

In IC technology and LSI technology, in order to improve operation speed and integration, a part of the electrical wiring on the electrical wiring board is replaced with optical wiring such as an optical fiber or an optical waveguide, and the optical signal is used instead of the electrical signal. Things have been done.

For example, Patent Document 1 discloses that an optical waveguide film is installed above an IC chip having an optical element on the surface, and optical communication is performed between the IC chip and the optical waveguide film. However, when optical communication is performed between a substrate provided with optical communication means such as an optical element and an optical communication means such as an optical waveguide as in Patent Document 1, these optical communication means are positioned with high accuracy. Thus, there is a problem that optical communication cannot be performed unless it is mounted, and there is a problem that optical loss (signal intensity) decreases unless light is collected.

In order to solve this problem, a lens (usually called a microlens. The shape is usually a plano-convex lens) is provided on the surface of the substrate. For example, Patent Document 2 discloses a substrate with a lens in which a microlens (plano-convex lens) is installed on the surface of a transparent substrate.

JP 2006-11210 A JP 2004-361858 A

Such a plano-convex lens is required to have high light transmittance and light condensing property (or collimating property), and when it has a plurality of plano-convex lenses, it is required that there is little variation in the above characteristics. In general, when these inspections are performed, a contact type scanning positioning meter, a non-contact type laser positioning meter, or the like may be used.
However, since many plano-convex lenses are formed in the form of a sheet in the microlens, the inspection method as described above has a problem that it takes a lot of time for inspection.

An object of the present invention is to solve the above-mentioned problems and to provide an inspection method capable of inspecting each lens of a lens sheet on which a large number of lenses are formed simply and efficiently.

The present invention provides the following inventions.
(1) A method for inspecting a lens sheet in which a lens is formed on at least a part of the sheet, the step A injecting inspection light into the lens, and an arbitrary direction in the thickness direction of the lens sheet from the bottom surface of the lens Step B of measuring at least one selected from light intensity, size, shape and position β of the substantial image of the inspection light through the lens at a distance α, and determining the quality of the lens from the measurement result A method for inspecting a lens sheet, comprising the step C.

(2) The inspection method for the lens sheet, wherein the inspection light source that outputs inspection light in the step A and the inspection light receiving unit that measures the inspection light in the step B inspects the lens sheet in a non-contact manner. .

(3) The inspection method of the lens sheet, wherein a spot diameter of the inspection light on the bottom surface of the lens is a size including the diameter of the lens.
(4) The lens sheet inspection method according to any one of the above, wherein, in the step A, before the inspection light is incident, a transparent substrate is installed on a sheet surface opposite to the surface on which the lens is formed.

(5) The said inspection method of the said lens sheet in which the said test | inspection light injects through the said transparent substrate in the said process A.
(6) In the step A, before the inspection light is incident, a reflecting plate is installed above the sheet surface opposite to the surface on which the lens of the sheet is formed, and the inspection light is formed on the surface on which the lens is formed. The method for inspecting a lens sheet according to any one of the above, wherein in the step B, the measurement is performed by measuring light reflected by the reflection plate through the lens.

(7) The method for inspecting the lens sheet, wherein the reflecting plate is installed in parallel with the sheet surface.
(8) At least two or more position recognition markers are installed at locations other than the lens on the lens sheet, and the relative positional relationship between the positions of the at least two position recognition markers and the imaging position β is measured. The lens sheet inspection method according to any one of the above, further comprising a step D.

(9) The inspection method for the lens sheet, wherein the position recognition marker is a reference position for determining an arbitrary distance α in the thickness direction of the lens sheet.
(10) Selected from the light intensity, size, shape and position ρ of the substantial image of the inspection light through the lens at an arbitrary distance α in the thickness direction of the lens sheet from the bottom surface of the lens The method further includes a step E of measuring at least one data of the lens R for which at least one data is known, and the step C of determining the quality of the lens is based on the comparison of the measurement data of the step E and the step B. The method for inspecting a lens sheet according to any one of the above, wherein the quality of the lens to be inspected is determined.

(11) The inspection method for a lens sheet according to any one of the above, further including a step F of measuring the diameter of the lens.
(12) Any of the above, wherein the positional relationship between the inspection light source that outputs inspection light in the step A and the inspection light receiving unit that measures the inspection light in the step B is defined in the sheet plane direction. 2. A method for inspecting a lens sheet according to 1.

(13) The step A and the step B are the steps in which the inspection light receiving unit is moved in a direction parallel to the sheet surface and the inspection is repeatedly or intermittently performed on a plurality of lenses. The lens sheet inspection method according to any one of the above.
(14) A lens sheet inspected by the lens sheet inspection method according to any one of the above.

(15) The lens sheet described above, wherein at least a part of the lens sheet on the lens optical axis is made of an organic compound.
(16) The lens sheet, wherein the lens sheet has flexibility.

(17) An optical waveguide with a lens in which the lens sheet according to any one of the above and an optical waveguide with a mirror are combined.
(18) An electric wiring board with a lens in which the lens sheet according to any one of the above and an electric wiring board are combined.

According to the method for inspecting a lens sheet of the present invention, it is possible to inspect a large number of lenses (such as microlenses) simply and efficiently.

It is sectional drawing which shows an example of the lens sheet used for the test | inspection method of this invention. It is sectional drawing which shows another example of the lens sheet used for the inspection method of this invention. It is sectional drawing which shows an example of the test | inspection method of this invention. It is sectional drawing which shows another example of the inspection method of this invention. It is a top view which shows an example of the image formation in the inspection method of this invention. It is a top view which shows another example of the imaging in the inspection method of this invention. It is a top view which shows another example of the imaging in the inspection method of this invention. It is a top view which shows another example of the imaging in the inspection method of this invention. It is a top view which shows another example of the imaging in the inspection method of this invention.

FIG. 1 shows a cross-sectional view of an example of a lens sheet used in the inspection method of the present invention. In FIG. 1, a plurality of plano-convex lenses 1 are formed on a sheet 4 as lenses. The lens sheet inspection method of the present invention is an inspection method applicable to a lens sheet having a lens formed on at least a part of the sheet. The lens in the present invention is usually a minute lens called a microlens. Further, the shape is usually a plano-convex lens 1, and the plano-convex lens is usually composed of a curved surface having condensing properties (or collimating properties) in the sheet vertical direction and the other surface in the curved inner direction. A lens having a flat portion (bottom surface) 2 is indicated. Since it is possible to inspect curved lenses, non-curved lenses, Fresnel lenses, etc. from the viewpoint of having a light condensing property (or collimating property), in the present invention, including these, a plano-convex lens is broadly defined. To do. The term “substantially flat” refers to a flatness that does not affect the characteristics of the practically opposing lens curved surfaces even if it is finely, partially, or entirely non-flat. For example, it may be convex or concave as long as it does not cause a problem in practice, and fine irregularities may be provided. Moreover, the shape which has a columnar member and the plano-convex lens part formed on this columnar member as described in an Example may be sufficient.

FIG. 3 is a sectional view showing an example of the inspection method of the present invention. In FIG. 3, the lens sheet is a sheet having one or more convex portions (lens curved surface) on at least one surface (or above the surface) on the sheet. Two or more convex portions (lens curved surfaces) may be arranged, and the sheet may be any member that holds the arrangement thereof. Further, it may be a lens sheet (an embodiment shown in FIG. 2) in which a concave portion is formed on one surface and a convex portion (lens curved surface) is formed in the concave portion. Alternatively, a lens sheet with a built-in lens embedded with a low refractive index layer having a low refractive index may be used.

An example of the lens sheet inspection method of the present invention is shown in FIG.
The inspection method of the present invention includes a step A in which inspection light 10 is incident on the plano-convex lens 1;
The imaging intensity, the imaging intensity, and the imaging intensity of the inspection light 10 through the plano-convex lens 1 at an arbitrary distance α in the thickness direction of the lens sheet from the bottom surface 2 of the plano-convex lens 1 and Measuring the shape of the imaging and / or the position β of the imaging B,
A step C for determining the quality of the plano-convex lens 1 from the substantial light intensity and / or image size and / or image shape and / or image position β measured in step B. .
The position β in the present invention indicates the position of image formation in the sheet plane direction, and represents the position in the X and Y directions when the measurement direction of the distance α is the Z direction with respect to the sheet.

The imaging light intensity and / or the imaging size and / or the imaging shape and / or the imaging light 10 through the plano-convex lens 1 at an arbitrary distance α in the thickness direction of the lens sheet. Since the quality of the plano-convex lens 1 is determined at the image formation position β, the transmittance of the plano-convex lens 1 (depends on the light intensity of the image formation), the refractive index (influence on the size of the image formation), Substantially condensing the lens regardless of variations in curvature (influences on imaging size, etc.), shape (influences on imaging size, shape, etc.), position (influences on imaging position, etc.), etc. Alternatively, since it is possible to perform the defect determination when the evaluation is performed using the collimating function and the variation is in a range in which the function of the plano-convex lens 1 is adversely affected, it is possible to perform an inspection capable of determining the quality with higher accuracy.

Image formation in the present invention refers to an image of light collected through a plano-convex lens, and refers to an image having an arbitrary ratio of intensity with respect to the maximum luminance or the area center luminance in the image. For example, as an example, when the maximum luminance of the unit area is 100%, a portion having a luminance near 50% of the unit area can be imaged. The arbitrary ratio may be 1 to 99%, and 10 to 90% is better because the contour of the image can be clarified, and more preferably 25 to 75%.

The substantial imaging measurement in the present invention is a direct measurement of the total light intensity, size, shape, and position β of the imaging, or an arbitrary region of the imaging (for example, used in actual use). Measurement of light intensity, size, shape, and position β incident within a light receiving element diameter equivalent to a light receiving element (preferably a circle or a rectangular shape). They are appropriately selected depending on the use and purpose. Of course, they may be used in combination. Details will be described later.

In particular, the inspection method of the present invention does not directly measure the shape (convex portion) of the lens, but actually inspects the lens by transmitting inspection light, so the lens transmittance (including the sheet transmittance) is also included. ), A refractive index variation, a foreign matter on the lens surface or the back surface (flat portion) of the lens, defects due to scratches, and the like can be detected, so that it is possible to make a good / bad determination with high accuracy.

In addition, since the inspection light source and the inspection light receiving unit can inspect the lens or the lens sheet (the housing provided with the lens) in a non-contact manner in the series of inspection processes, There is an advantage that the fear of adhesion is reduced, and the inspection light receiving unit, and further the inspection light source is inspected without being fixed to the sheet, so that by moving them relatively in the surface direction of the sheet, The lens and lens sheet can be inspected continuously. Therefore, there is an advantage that the inspection time can be shortened.

In the inspection method of the present invention, the spot diameter of the inspection light on the bottom surface of the lens is not particularly limited as long as the inspection can be performed, but it is preferable that the spot diameter includes the lens diameter. Thereby, even if a positional deviation occurs between the lens and the inspection light source, the inspection light can be incident on the lens, so that the inspection can be performed satisfactorily. Examples of the positional deviation include a case where the lens is formed with a deviation from a design value, and a case where a deviation of the lens sheet that may occur when measuring a plurality of lenses continuously occurs. From the above viewpoint, the size of the spot diameter is preferably larger than 100% of the lens diameter and not larger than the size including the lens sheet. The size is preferably 150% or more and 100000% or less of the diameter of the lens from the viewpoint of easy control of light uniformity and spread angle, and is 180% or more and 20000% or less. Further, it is more preferable because inspection light can be incident on the substrate and inspection efficiency can be increased.

In addition, as shown in FIG. 3, it is preferable to install a transparent substrate (transparent plate 8) on the sheet surface (flat portion 3) opposite to the convex surface of the plano-convex lens 1 in the step A of the present invention. More specifically, the transparent plate 8 may be applied to the sheet surface (flat portion 3), and the lens sheet and the transparent plate 8 may be grounded. Thereby, even if it is a thin lens sheet of the sheet | seat 4, a lens sheet | seat etc. which has flexibility, the distortion and curvature of the sheet | seat 4 can be reduced. As a result, there are advantages that the Z direction, X direction, and Y direction of the sheet can be easily defined, inspection is easy, and pass / fail judgment is easy. In addition, since the lens sheet with the transparent plate 8 can be handled like a thick lens sheet, handling properties are also improved. From the above viewpoint, it is preferable to use a transparent plate 8 having a higher elastic modulus than the lens sheet or a thick transparent plate 8. A transparent plate 8 having a high elastic modulus and a large thickness is more preferable.

Further, by using the transparent plate 8 having transparency with respect to the inspection light 10, the inspection light 10 can be made incident through the transparent plate 8, and inspection is performed in a state in which distortion and warping of the sheet 4 are reduced. Is preferable. From the above viewpoint, the transparent plate 8 is preferably a transparent plate 8 having a degree of transparency that does not interfere with the inspection with respect to the inspection light 10 or having a certain transmittance in the plane. . From the above viewpoint, as shown in FIG. 3, at least the inspection light source 6 and the inspection light receiving unit 7 are provided so as to be substantially opposed to each other with the transparent plate 8 and the lens sheet interposed therebetween so as not to touch the lens sheet. Preferably it is.

Further, as shown in FIG. 4 which is another example of the method for inspecting a lens sheet of the present invention, when the reflector 9 is provided, at least the inspection light source 6 and the reflector 9 in the direction opposite to the lens sheet. The inspection light receiving unit 7 is preferably oriented in a substantially coaxial direction so as not to touch the lens sheet. When the reflection plate 9 is used, an optical gap may be provided between the sheet 4 and the reflection plate 9. As a result, the inspection light 10 transmitted through a portion other than the plano-convex lens 1 can be incident on the plano-convex lens 1 after being reflected by the reflecting plate 9.

The example of FIG. 4 will be described in more detail. In step A of the present invention, as shown in FIG. 4, a reflecting plate 9 is installed above the surface of the sheet 4 opposite to the plano-convex lens 1, and the inspection light 10 is irradiated from the convex surface side and reflected by the reflecting plate 9. Then, the inspection light 10 reflected by the reflecting plate 9 may be incident on the plano-convex lens 1. Accordingly, the inspection light 10 can be incident and received from substantially the same direction with respect to the surface of the sheet 4.

The reflector 9 is preferably installed in parallel with the sheet 4. Thereby, since the reflected inspection light 10 can be aligned at a certain angle, it is possible to perform the inspection under the same conditions when inspecting a plurality of plano-convex lenses 1. For this reason, it is possible to determine the quality of each plano-convex lens 1 with high accuracy.

Further, as shown in FIGS. 1 and 2, the lens sheet has at least two or more position recognition markers 5 at locations other than the plano-convex lens 1, and the positions of the at least two position recognition markers 5 It is good to have the process D which measures the relative positional relationship with the position (beta).
Thereby, the deviation from the design value of the lens can be easily measured. Also, in the case of a defective mode in which the condensing position is decentered with respect to the center of the lens diameter by measuring the relative positional relationship between the position of the position recognition marker and the imaging position β. A pass / fail judgment is possible. For example, when the state in which the image 110 appears as shown in FIG. 5 is regarded as a non-defective product, the state is like the image 113 shown in FIG.

The position recognition marker 5 may be a reference position in the thickness direction at an arbitrary distance α in the thickness direction of the lens sheet, instead of the bottom surface 2 of the lens. As a result, the distance α can be calculated with high accuracy even if the thickness of the lens sheet varies. When the above-described transparent plate 8 is sufficiently rigid and has a good flatness, the inspection light source 6 and the inspection light receiving unit 7 are moved in the horizontal direction with respect to the transparent plate 8 so that the plurality of plano-convex lenses 1 are provided. A constant distance α can be ensured, but when it is desired to calculate the distance α with higher accuracy, a plurality of the position recognition markers 5 are arranged in the sheet 4 and the plurality of reference positions are measured to measure the surface. Inspection can be performed in consideration of variations in the thickness direction.
The calculation of the reference position may be performed before the process B.

In the method for inspecting a lens sheet of the present invention, the plano-convex lens R is compared with the plano-convex lens R whose light intensity and / or image size and / or image shape and / or image position ρ is known. The light intensity and / or the magnitude and / or the shape and / or the imaging of the inspection light through the plano-convex lens R at an arbitrary distance α in the thickness direction of the lens sheet from the bottom surface It is preferable to further include a step E of measuring the position ρ (position with respect to the position recognition marker R provided in the vicinity of the plano-convex lens R).
Note that the distance α of the plano-convex lens R may be the same as or different from the distance α of the plano-convex lens for determining pass / fail, but if different, the imaged light at the distance α via the plano-convex lens R is different. Intensity and / or imaging size and / or imaging shape and / or imaging position ρ, and the imaging light intensity and / or imaging size at the distance α of the plano-convex lens for determining pass / fail It is only necessary to obtain a correlation that does not hinder the determination of the quality of the imaging shape and / or the imaging position β. When the distance α is the same, it is more preferable because the pass / fail determination can be made by directly comparing the imaging characteristics of the plano-convex lens R and the plano-convex lens for determining pass / fail.

By having this step E, for example, the difference between the divergence angle of the light source and the inspection light source under actual use conditions, the difference in image size at the diameter and distance α of the light receiving unit under actual use conditions, Even when there is a difference between the distance from the sheet surface to the light receiving unit under actual use conditions and the distance α, and there is a positional deviation (particularly in the sheet surface parallel direction) between the inspection light source 6 and the inspection light receiving unit 7, By determining the quality of the plano-convex lens 1 from the difference from the light intensity of the imaging and / or the imaging and / or imaging shape and / or the imaging position ρ with respect to the process B, A good / bad determination can be made.

The process E may be performed before, during or after the process B. The determination of the quality of the lens may be performed after performing Step E and Step B. It is further preferable to perform at least one time immediately after, during, or immediately after the process B because a more accurate pass / fail determination is possible.

The method for inspecting a lens sheet of the present invention may include a step F of measuring the diameter of the plano-convex lens 1. By including this step F, it is possible to inspect whether the total amount of the inspection light 10 incident on the plano-convex lens 1 is appropriate. This step is particularly preferably used when the inspection light 10 is incident with a spot diameter larger than the diameter of the plano-convex lens 1. From the above viewpoint, the light intensity within the diameter (diameter) of the plano-convex lens may be measured at this time. Similarly, in the process E, the diameter of the plano-convex lens R and / or the light intensity that passes through the diameter is measured, and the quality is determined from the result and the measurement result of the process F.

In the lens sheet inspection method of the present invention, the positional relationship between the inspection light source 6 and the inspection light receiving unit 7 may be defined in the plane direction of the sheet 4. Thus, when inspecting a plurality of plano-convex lenses 1 or inspecting a plurality of plano-convex lenses 1, the inspection light 10 enters the plano-convex lens 1 at a certain angle (preferably perpendicular to the plano-convex lens 1). Since the inspection light 10 can be received at a certain angle (preferably in a direction perpendicular to the plano-convex lens 1), a highly accurate inspection can be performed. The relationship between the distance between the plano-convex lens 1 in the process B and the inspection light source 6 and the inspection light receiving unit 7 and the distance between the plano-convex lens R in the process E and the inspection light source 6 and the inspection light receiving unit 7 are constant. It is preferable that the distance is defined, and the positional relationship between the inspection light source 6 and the inspection light receiving unit 7 is also defined in the plane parallel direction of the sheet 4.

The positional relationship between the inspection light source 6 and the inspection light receiving unit 7 is not particularly problematic as long as the inspection light 10 can be incident on the plano-convex lens 1 and the inspection light 10 can be received through the plano-convex lens 1. When the light source 6 and the inspection light receiving unit 7 are disposed, the respective positions are defined so that the brightness of the spot diameter irradiated on the plano-convex lens 1 and the angle of the inspection light 10 are constant within a range that does not hinder the inspection. Preferably, the positions of the inspection light source 6 and the inspection light receiving unit 7 may be defined using the plano-convex lens 1 to be measured, but more preferably, the plano-convex lens R having a known shape may be used. Preferred (because the plano-convex lens 1 to be measured may have an unfavorable shape).

Further, the positional relationship between the inspection light source 6 and the inspection light receiving unit 7 may be fixed. Thereby, it can test | inspect without each positional relationship shifting | deviating in the middle of a test | inspection. At this time, if the interval between the inspection light source 6 and the sheet 4 and the gap between the inspection light receiving unit 7 and the sheet 4 are sufficiently secured, for example, when measuring the diameter of the plano-convex lens 1 and when measuring the imaging, the sheet Even if the inspection light source position in the direction perpendicular to the surface is different, the variation in the incident angle of the inspection light 10 incident on the plano-convex lens 1 can be reduced.

In the lens sheet inspection method of the present invention, the plurality of plano-convex lenses 1 in which the process A and the process B move at least the inspection light receiving unit 7 in the direction parallel to the surface of the sheet 4 and the inspection light 10 is incident thereon. Is repeated continuously or intermittently. Continuous is a method in which a plurality of plano-convex lenses 1 are inspected in order while maintaining the distance α, and a method in which the sheet 4 is inspected while maintaining the distance α during step B. Intermittently means a method in which the position recognition marker 5 is recognized, a distance α is calculated for each position recognition marker 5 and one or a plurality of plano-convex lenses 1 are inspected. Refers to inspection with movement of direction. It is preferable to carry out continuously from the viewpoint of inspection efficiency. Whichever method is used, the process B may be performed in a state in which the distance α is secured for each plano-convex lens 1.

This inspection method can provide a good lens sheet with a function as a lens. In particular, a lens array sheet in which a plurality of lenses are arranged is preferable because a function as a lens for each lens is secured.

In addition, in the case where a lens sheet is made of an organic compound that is likely to be heated or deformed during the manufacturing process, at least part of the lens on the optical axis (perpendicular to the sheet), variations in transmittance, refractive index, etc. may occur. Therefore, the inspection method of the present invention that can be inspected in consideration of them is particularly useful, and the lens sheet inspected by the inspection method of the present invention has been confirmed to function as a lens, so it can be used without any problem. it can.

Specifically, when a lens is formed by intaglio or injection molding, the organic compound depends on how heat is applied, variation in total calorie, degree of crosslinking at the molecular level, variation in its style, variation in pressure applied to the lens sheet, etc. Density may occur in the density. Density of density tends to cause variations in transmittance and refractive index. In addition, when a resist pattern for lens formation is formed into a lens by thermal reflow, as in the above, how to apply heat, variation in total heat, degree of crosslinking at the molecular level It is also possible that the density is uneven due to variations in the pattern and the like, or variations in shape due to variations in fluidity and surface tension during thermal reflow. In addition, when a developer is used when forming a resist pattern, the influence of the developer may be considered.

Examples of organic compounds used in the lens sheet include polyethylene terephthalate, polybutylene terephthalate, polyester such as polyethylene naphthalate, polyolefin such as polyethylene and polypropylene, polyamide, polycarbonate, polyphenylene ether, polyether sulfide, polyarylate, liquid crystal polymer, Examples include polysulfone, polyethersulfone, polyetheretherketone, polyetherimide, polyamideimide, polyimide, acrylic resin, epoxy resin, phenol resin, and cured products thereof.

Also, in the case of lens sheets having flexibility that easily accompany warpage and deformation, this inspection method can be inspected by correcting or taking them into account, so it is also useful as an inspection method for those lens sheets. Since the lens sheet inspected by the inspection method of the present invention has been confirmed to function as a lens, it can be used without any problem.

The lens sheet as described above can be an optical waveguide with a lens combined with an optical waveguide with a mirror. The optical waveguide is preferably composed of a core pattern through which light propagates and a cladding layer covering the core pattern. The optical path conversion mirror may be provided on the optical axis of the core pattern. In particular, when a lens (lens sheet) is disposed above the optical path conversion mirror, light propagating through the optical waveguide can be reliably condensed or collimated through the optical path conversion mirror and the lens. Furthermore, when a plurality of core patterns and optical path conversion mirrors are combined with multi-core mirrored optical waveguides arranged at regular intervals and the lens sheet obtained in the present invention, each optical path conversion mirror and each lens Since the positional relationship is also confirmed, it is possible to align the lens with respect to any of the optical path conversion mirrors by combining them in a lump, and good characteristics can be obtained.

The lens sheet as described above can be an electric wiring board with a lens combined with an electric wiring board. The electric wiring board is particularly preferably an electric wiring board for mounting an optical element on which a light receiving element or a light emitting element is mounted, and the electric wiring for mounting these elements is preferably formed on an insulating substrate. When the lens sheet obtained by the inspection method of the present invention is arranged on the insulating substrate opposite to the optical element with the light receiving or emitting surface of the optical element facing the insulating substrate, the light is received or transmitted well through the lens. Can do. At this time, the insulating resin between the light emitting / receiving surface and the lens is preferably transparent or has an opening.

Furthermore, when an electric wiring board in which a plurality of light receiving and / or light emitting elements are arranged and mounted at a predetermined interval and a lens sheet obtained by the present invention are combined, each light receiving or / and light emitting part and each lens are combined. Since the positional relationship is also confirmed, the lens can be aligned with respect to any light receiving and / or light emitting portion by combining them together, and good characteristics can be obtained.
Below, the inspection method of the lens sheet of this invention is demonstrated in detail for every process.

(Process A)
The method for inspecting a lens sheet of the present invention includes a step A in which an inspection light 10 is incident on a lens (a plano-convex lens 1 in FIG. In step A, the incident direction of the inspection light 10 on the plano-convex lens 1 may be from either the convex side (the side opposite to the flat part 3) or the flat part 3 side.

The inspection light 10 may be infrared light, visible light, ultraviolet light, or light having a single wavelength or a plurality of wavelengths as long as it can be received by the inspection light receiving unit 7. It is more preferable to use the wavelength of light that passes through the plano-convex lens 1 because an inspection can be performed in consideration of the wavelength dependence of the refractive index.

When inspection is performed on a plurality of plano-convex lenses 1 or when inspection light 10 is incident on a plano-convex lens R described later, the input angle of the inspection light 10 to each plano-convex lens 1 (or plano-convex lens R) is It is good to keep it almost constant. This makes it easy to determine whether the light intensity, size, shape, and position β of the image formation are good or bad (or easy comparison with the image formation of the plano-convex lens R).

The spread angle of the inspection light 10 incident on the plano-convex lens 1 (or the plano-convex lens R) is in a range that does not affect the quality determination, and the plano-convex lens 1 collects light or collimates (functions as a lens). Any spread angle within the range that can be confirmed is acceptable. This is because the inspection method of the present invention can determine whether the light collected by the plano-convex lens 1 is good or bad, so that the inspection light 10 having a divergence angle in a range satisfying the above can be inspected. it can. Further, even in the actual use state, even the plano-convex lens 1 for collimation can be inspected using the condensing inspection light 10. Pass / fail judgment may be made by collimated imaging by solving a plano-convex lens using incident light having an arbitrary divergence angle. Specifically, the divergence angle (half angle) is preferably greater than 0 ° to 75 °, and more preferably greater than 0 ° to 45 ° from the viewpoint of light collection. From a viewpoint, it is more preferable that the angle is 5 ° to 40 °, and it is most preferable that the angle is 5 ° to 30 ° from the viewpoint of easily obtaining a spot diameter having a uniform intensity. The light incident on the plano-convex lens R or the plano-convex lens 1 may further have a more uniform angular distribution within the above-mentioned angle range.

(Process B)
In the method for inspecting a lens sheet of the present invention, as the process B, the inspection light 10 is substantially transmitted through the plano-convex lens 1 at an arbitrary distance α in the thickness direction of the lens sheet from the bottom surface 2 of the lens (plano-convex lens 1). The light intensity of the image and / or the size of the image and / or the shape of the image and / or the position β of the image are measured. As a method of obtaining the image, for example, a projection plate is disposed at a position of the distance α, or the image is obtained as an image by focusing on the distance α using a camera module or the like. Use of a projection plate or a camera module is preferable because the light intensity, size, position, and position can be obtained as image information. From the viewpoint of easily obtaining the positional relationship between the position recognition marker 5 and imaging, it is best to use a camera module.

The arbitrary distance α may be a distance at which the angle of the inspection light 10 through the plano-convex lens 1 can be confirmed or a distance at which the changing process can be confirmed. The distance may be any of the collected spot, the process of diverging after being collected, or the spot where collimation can be confirmed. In the case of the plano-convex lens 1 having the same focal length, it is preferable to set the distance α to be the same within a range that does not hinder the pass / fail judgment for each plano-convex lens 1. If so, the distance α may be set for each.

Further, one or more distances α may be set for one plano-convex lens 1, and two or more distances α may be set. By setting two or more distances α and measuring the light intensity, size, shape, and position β of the image, the plano-convex lens 1 can be inspected with higher accuracy.

When using a camera module, after focusing on the bottom surface 2 of the lens that is the starting point of the distance α and grasping the reference position, the position of the camera module in the opposite direction to the optical axis of the inspection light by the distance α The image information of the image at the distance α can be acquired by moving the focus position and defocusing.

(Process C)
In the method for inspecting a lens sheet of the present invention, as the process C, the optical intensity of the image and / or the size of the image and / or the shape of the image and / or the position β of the image is measured from the plano-convex lens. Judge the quality.

For example, when there is a defective plano-convex lens that is lower than the predetermined transmittance of the plano-convex lens 1 (for example, when it has an image 112 with low intensity as shown in FIG. 7 (non-defective product is shown in FIG. 5)), The light intensity of image formation through the defective plano-convex lens is smaller than the light intensity of image formation of the other non-defective plano-convex lens 1. Thereby, it can be determined that the defective plano-convex lens is defective. Comparing the light intensity of the image formed by the plano-convex lens R and the light intensity of the image formed by the plano-convex lens 1 to be measured is preferable because it is possible to determine the quality more accurately. The light intensity may be the total light amount, the maximum intensity, the light distribution and its distribution shape, and is appropriately determined depending on the intended use.

As another example, when there is a defective plano-convex lens that is larger (or smaller) than a predetermined curvature of the plano-convex lens, and the distance α is closer to the lens sheet side than the height at which the inspection light is most condensed, The size of the image formation becomes small (or large) (for example, when the image formation 111 has a large image formation size as shown in FIG. 6 (non-defective product is shown in FIG. 5)). Thereby, it can be determined that the defective plano-convex lens is defective. It is preferable to compare the image formation size of the plano-convex lens R with the image formation size of the plano-convex lens to be measured because it is possible to determine the quality more accurately.

As another example, when there is a defective plano-convex lens having foreign matter or scratches on the optical axis of the plano-convex lens, the shape of the image formed through the defective plano-convex lens is such as The shadow is projected in a distorted shape. Thereby, it can be determined that the defective plano-convex lens is defective (for example, when it has an image 114 having a different image shape as shown in FIG. 9 (the non-defective product is shown in FIG. 5)). It is preferable to compare the shape of the image of the plano-convex lens R with the shape of the image of the plano-convex lens 1 to be measured because it is possible to determine the quality more accurately.

As another example, a cross section in which the plano-convex lens 1 is shifted from a predetermined position in any one of the lens sheet plane directions, or the center of the diameter of the plano-convex lens 1 is shifted from the most convex portion. When there is a defective product such as a plano-convex lens 1 having an irregular shape, the image formation position β (image formation position in the plane parallel direction of the sheet 4) is different from a predetermined position (for example, as shown in FIG. 8). When the image has an image 113 different from the predetermined position (the non-defective product is shown in FIG. 5)). Thereby, it can be determined that the defective plano-convex lens is defective. As for the image formation position, for example, the quality of the position β can also be determined by comparing the image formation center point of a non-defective lens (or lens R) with the point that can be determined as the center of the image formation 113.

It is preferable to compare the shape of the image formed by the plano-convex lens R with the shape of the image formed by the plano-convex lens 1 to be measured because it is possible to determine the quality more accurately. In particular, when the angle of the inspection light source cannot be set satisfactorily and the average incident angle of the inspection light 10 is tilted with respect to the normal direction of the lens sheet, the center of the diameter of the plano-convex lens 1 and the image are formed. Although the center may deviate, the quality can be accurately judged by comparing the imaging positions of the plano-convex lens 1 and the plano-convex lens R to be inspected with the same setup (setting of the inspection light source angle).

As another example of determining the light intensity, size, shape, and position β of the above-described image formation, there is a method of measuring the light intensity incident within a predetermined range in the image formation. In this case, if the size, shape, or position β of the image formation is defective, the image formation deviates from the predetermined range. As a result, the intensity of light incident within a predetermined range is reduced, and it can be determined that the light is defective. In other words, pass / fail judgment is performed by indirectly converting the magnitude, shape, and position β of the image to light intensity. Also in this case, it can be said that the pass / fail judgment is substantially performed by the light intensity of the image formation and / or the size of the image formation or / and the shape of the image formation or / and the position β of the image formation.

The predetermined range described above may be selected as appropriate, for example, a shape having a correlation with the shape of the light receiving portion of the light receiving element when actually used. It may be a range having a certain shape and area such as a circle, an ellipse, and a rectangle. In this way, even if the image size, shape, and position are microscopically deviated within the specified range, the function as a lens (actually usable) can be confirmed. be able to. Further, the position in the predetermined range may be a theoretical imaging position calculated from the position recognition marker 5.
In the case of performing the inspection in the predetermined range, it is possible to acquire image formation information by the camera module and measure the luminance within the predetermined range by various image processing.

(Process D)
In the method for inspecting a lens sheet of the present invention, as step D, the lens sheet has at least two position recognition markers 5 at a place other than the lens (plano-convex lens 1), and at least two of the position recognition markers 5; It is preferable to further include a step D of measuring a relative position with respect to the imaging position β.

Two position recognition markers 5 may be provided for at least one lens sheet, and two or more for each plano-convex lens. For example, when twelve plano-convex lenses are one unit (product unit) and the lens sheet includes a plurality of units, two or more position recognition markers 5 are provided per unit. This position recognition marker 5 is preferable because it can be used as the position recognition marker 5 when combined with an optical waveguide with a mirror or an electric wiring board.

By having two or more position recognition markers 5, the in-plane angular deviation of the plano-convex lens 1 can also be measured.
The position recognition marker 5 is preferably provided at a location other than the plano-convex lens 1, and there is no problem as long as the shape is visible, but it is a convex portion or a concave portion formed on the surface of the lens sheet. Good. Furthermore, it is good to have a fixed height angle | corner with respect to the sheet | seat plane which is easy to visually recognize like a cylinder, a polygonal column, a cone, polygonal guess, and those composite shape.

(Process E)
In the inspection method of the present invention, as the process E, the plano-convex lens R whose imaging light intensity and / or imaging size and / or imaging shape and / or imaging position ρ is known is described above. The light intensity and / or the size and / or the shape of the imaging of the inspection light through the plano-convex lens R at an arbitrary distance α in the thickness direction of the lens sheet from the bottom surface of the convex lens R and / or Alternatively, the imaging position ρ may be measured.

The plano-convex lens R at this time is a standard plano-convex lens, which may be a non-defective product or a defective product, and may be a standard for determining a threshold value for determining the quality of a plano-convex lens as a measurement sample. More preferably. Since the light intensity of the imaging and / or the imaging size and / or the imaging shape and / or the imaging position ρ of the plano-convex lens R are known, for example, the output of the inspection light 10 from the inspection light source 6 is The above can be taken into account when it is lowered (or raised), or because it is possible to grasp that the positions of the inspection light source 6 and the inspection light receiving unit 7 are shifted in the plane parallel direction, etc. The quality of the measurement sample can be accurately determined. The image formation position ρ may be a correlation position with adjacent image formation, or a position based on a position recognition marker arranged on a lens sheet provided with the plano-convex lens R. Thereby, for example, when the position recognition marker 5 in the measurement sample and its imaging position are measured using image processing, even if an error (for example, calibration deviation) occurs in the processing, the imaging position ρ By measuring the error, it is possible to cancel out the error and perform a quality determination with high accuracy.

(Another aspect of step C)
In the inspection method of the present invention, as the step C, the light intensity and / or the image size and / or the image shape and / or the image position of the image formed by the steps E and B substantially. The quality of the lens may be determined from the difference from ρ.
The lens of the lens to be measured is compared by comparing the threshold value of the imaging light intensity calculated from step E, the upper and lower limits of the imaging size, the imaging shape, and the upper and lower limits of the deviation amount from the imaging position ρ. Accurate quality determination can be made.

(Process F)
In the inspection method of the present invention, it is better to measure the diameter of the lens (plano-convex lens 1) as step F. By measuring the diameter of the plano-convex lens 1, it is possible to determine that the plano-convex lens 1 having a diameter larger than the standard value or the plano-convex lens 1 having a smaller diameter is defective. A comparison with the plano-convex lens R is better because a more accurate pass / fail judgment can be made.

Next, each member used in the inspection method of the present invention will be described in detail.

The inspection light source is a part that outputs inspection light that is incident on the lens. An LED (Light Emitting Device), a laser, a halogen lamp, or the like can be used, and the light from the optical fiber, optical waveguide, light pipe, etc. As long as the light is irradiated at a uniform angle or area that does not hinder the inspection through the slab. In order to achieve the above, an optical system such as a lens or a mirror may be provided as appropriate.

The inspection light 10 incident on the lens from the inspection light source is not particularly limited as long as it is a wavelength of light that can be transmitted through the lens (plano-convex lens 1), but from the viewpoint of handling, infrared light, visible light, and ultraviolet light are used. These may be a single wavelength or a plurality of wavelengths. The wavelength of light that is transmitted through the plano-convex lens 1 during actual use is more preferable because the material-dependent transmission loss of the plano-convex lens 1 can be taken into account. In particular, in the case of a material whose transmittance varies depending on the wavelength, it is preferable that the wavelength of the light transmitted through the plano-convex lens 1 during actual use. Examples of the material include a plano-convex lens that the organic material has in at least a part on the optical axis and a sheet thereof.
In addition, the number of light sources, the amount of light, and the position may be appropriately adjusted so that the spot diameter and the spread angle of the light applied to the plano-convex lens 1 are as uniform as possible in the spot portion.

The inspection light receiving unit 7 is a part that receives the inspection light 10 emitted from the lens, and a light receiving element, a camera module, or the like is used. The use of a camera module is more preferable because the position of the plano-convex lens 1 and its imaging and position recognition marker 5 can be obtained from image information. When using a camera module to measure light collection or divergence through a plano-convex lens, an image of the image is acquired through a lens that has a short focal length and can also recognize angular light components. May be.

In addition, the inspection light source and the inspection light receiving unit need only be substantially coaxially opposed or in the same direction as the light beam. For example, the optical axis is converted by approximately 90 ° between the inspection light source and the inspection light receiving unit. Even if it has such a reflecting mirror, it is possible to determine whether the plano-convex lens 1 is good or bad even in the case of a structure in which the reflecting mirror and the plano-convex lens are fused. The substantially 90 ° refers to an angle at which the reflection mirror can perform regular reflection or total reflection. Note that the case where the incident angle to the reflection mirror is approximately 0 ° and the reflection angle is approximately 0 ° is equivalent to the above-described inspection method using the reflector. In addition, an optical path (for example, an optical fiber or an optical waveguide) may be provided between the inspection light source and the inspection light receiving unit within a range that does not hinder the inspection of the plano-convex lens.

The transparent plate 8 used in the present embodiment is preferably a plate having transparency capable of transmitting the inspection light 10 and being more rigid than the sheet 4. Since it is more elastic than the sheet 4 or is thick, it is preferable because rigidity is easily obtained. It is more preferable that the transparent plate has higher elasticity and thickness than the sheet 4.

Specific materials include glass, quartz, transparent resin, silicon wafer and the like. Examples of the transparent resin include polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, polyolefins such as polyethylene and polypropylene, polyamide, polycarbonate, polyphenylene ether, polyether sulfide, polyarylate, liquid crystal polymer, polysulfone and polyethersulfone. , Polyether ether ketone, polyether imide, polyamide imide, polyimide and the like. Moreover, a releasable adhesive may be applied to them, and the transparent plate 8 and the lens sheet may be bonded together via the adhesive. The transparent plate 8 may be provided with an antireflection film.

The thickness of the transparent plate 8 is preferably 50 μm to 20 mm from the viewpoint of easily obtaining rigidity and easy handling, and is more preferably 100 μm to 15 mm from the viewpoint of low warpage, from the viewpoint of easily obtaining flatness. 0.5 mm to 10 mm is even better.

The reflecting plate 9 used in the present embodiment is not particularly limited as long as it can reflect the inspection light 10 and may have a reflecting film. The reflectance may be constant within a range that does not hinder the inspection within the surface of the sheet 4. As the reflective film, a reflective metal film such as Ag, Al, Cu, Au, Ni, Cr, Pt, Ti, Pd, and a laminate or alloy thereof is used. As shown in FIG. 4, a reflective film may be provided on the surface of the transparent plate 8 opposite to the lens sheet. By providing a reflective film on the surface of the transparent plate 8 opposite to the lens sheet, it is preferable because the distance between the sheet 4 and the reflective plate 9 can be kept constant.

The position recognition marker 5 provided on the lens sheet only needs to be provided on a portion other than the lens (plano-convex lens 1). For example, a convex portion protruding from the sheet surface, a concave portion recessed from the sheet surface, or the like is preferable. . FIG. 1 shows an example of a convex position recognition marker 5 and FIG. 2 shows an example of a concave position recognition marker. Further, the shape is not particularly limited, but the shape from the lens sheet vertical direction may be a circle, a rectangle, a star, a cross, a composite shape thereof, or the like. When two or more position recognition markers 5 are provided on one lens sheet, the position of the plano-convex lens 1 can be defined. If two or more position recognition markers 5 are provided for each unit composed of a plurality of plano-convex lenses 1, the position recognition marker 5 can be used even when the unit is later separated into individual units. For example, an electric wiring board or mirror It functions as a position recognition marker 5 when combined with the attached optical waveguide.

By using the position recognition marker 5 as the reference point of the distance α or the reference point of the position β, it is possible to always inspect the imaging at a fixed arbitrary distance α and calculate the position β with high accuracy.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example, unless the summary is exceeded.
Example 1
A lens sheet was produced by the following procedure.
[Production of resin layer for position recognition marker formation]
<(A) Base polymer; Production of (meth) acrylic polymer (A-1)>
46 parts by mass of propylene glycol monomethyl ether acetate and 23 parts by mass of methyl lactate were weighed in a flask equipped with a stirrer, a cooling pipe, a gas introduction pipe, a dropping funnel, and a thermometer, and stirred while introducing nitrogen gas. . The liquid temperature was raised to 65 ° C., 47 parts by weight of methyl methacrylate, 33 parts by weight of butyl acrylate, 16 parts by weight of 2-hydroxyethyl methacrylate, 14 parts by weight of methacrylic acid, 2,2′-azobis (2,4-dimethylvaleronitrile ) A mixture of 3 parts by mass, 46 parts by mass of propylene glycol monomethyl ether acetate and 23 parts by mass of methyl lactate was added dropwise over 3 hours, followed by stirring at 65 ° C. for 3 hours, and further stirring at 95 ° C. for 1 hour. A (meth) acrylic polymer (A-1) solution (solid content: 45% by mass) was obtained.

(Measurement of weight average molecular weight)
As a result of measuring the weight average molecular weight (in terms of standard polystyrene) of (A-1) using GPC (“SD-8022”, “DP-8020”, and “RI-8020” manufactured by Tosoh Corporation), It was 9 × 10 ⁴ . As the column, “Gelpack GL-A150-S” and “Gelpack GL-A160-S” manufactured by Hitachi Chemical Co., Ltd. were used. Tetrahydrofuran was used as the eluent, the sample concentration was 0.5 mg / ml, and the elution rate was 1 ml / min.

(Measurement of acid value)
As a result of measuring the acid value of A-1, it was 79 mgKOH / g. The acid value was calculated from the amount of 0.1 mol / L potassium hydroxide aqueous solution required to neutralize the A-1 solution. At this time, the point at which the phenolphthalein added as an indicator changed color from colorless to pink was defined as the neutralization point.

<Preparation of resin varnish for position recognition marker formation>
(A) As a base polymer, 84 parts by mass of the A-1 solution (solid content 45% by mass) (solid content 38 parts by mass), (B) Urethane (meth) acrylate having a polyester skeleton as a photocuring component (Shin Nakamura) 33 parts by mass of “U-200AX” manufactured by Chemical Industry Co., Ltd., and 15 parts by mass of urethane (meth) acrylate having a polypropylene glycol skeleton (“UA-4200” manufactured by Shin-Nakamura Chemical Co., Ltd.), (C) heat As a curing component, 20 parts by mass of a polyfunctional block isocyanate solution (solid content: 75% by mass) obtained by protecting an isocyanurate type trimer of hexamethylene diisocyanate with methyl ethyl ketone oxime (“Sumijour BL3175” manufactured by Sumika Bayer Urethane Co., Ltd.) (Solid content 15 parts by mass), (D) 1- [4- (2-hydroxyethyl) as a photopolymerization initiator Xyl) phenyl] -2-hydroxy-2-methyl-1-propan-1-one (“Irgacure 2959” manufactured by Ciba Japan KK), bis (2,4,6-trimethylbenzoyl) phenylphosphine 1 part by mass of oxide (“Irgacure 819” manufactured by Ciba Japan Co., Ltd.) and 23 parts by mass of propylene glycol monomethyl ether acetate as an organic solvent for dilution were mixed with stirring. After pressure filtration using a polyflon filter having a pore diameter of 2 μm (“PF020” manufactured by Advantech Toyo Co., Ltd.), degassing was performed under reduced pressure to obtain a resin varnish for forming a position recognition marker.

<Preparation of Resin Layer (Film) for Position Recognition Marker Formation>
The position recognition marker forming resin varnish obtained above is coated on a non-treated surface of a PET film (“Cosmo Shine A4100” manufactured by Toyobo Co., Ltd., thickness 50 μm) as a support film. -MC, manufactured by Hirano Tech Seed Co., Ltd., dried at 100 ° C. for 20 minutes, and surface-release PET film (“Purex A31” manufactured by Teijin DuPont Films Co., Ltd., thickness 25 μm) as a protective film. The resin film for sticking and position recognition marker formation was obtained.
The thickness of the resin layer (film) for position recognition marker formation can be arbitrarily adjusted by adjusting the gap of the coating machine, and will be described in the examples. The film thickness of the resin layer for position recognition marker formation described in the examples is the film thickness after coating and drying.

<Preparation of lens member-forming resin layer (film)>
A flask equipped with a stirrer, reflux condenser, inert gas inlet and thermometer was charged with 190 parts by mass of propylene glycol monomethyl ether acetate, heated to 80 ° C. in a nitrogen gas atmosphere, and the reaction temperature was raised to 80 ° C. 1. While maintaining, 10 parts by weight of methacrylic acid, 1 part by weight of n-butyl methacrylate, 74 parts by weight of benzyl methacrylate, 15 parts by weight of 2-hydroxyethyl methacrylate, and 2,2′-azobis (isobutyronitrile) 5 parts by mass were uniformly dropped over 4 hours. After completion of the dropping, stirring was continued at 80 ° C. for 6 hours to obtain a binder polymer (a) solution (solid content: 35% by mass) having a weight average molecular weight of about 30,000.
Next, 2,2-bis (4- (di (meth) acryloxypolyethoxy) phenyl) was added to 200 parts by mass (solid content: 70 parts by mass) of the binder polymer (a) solution (solid content 35% by mass). 8 parts by mass of propane, 22 parts by mass of β-hydroxyethyl-β ′-(meth) acryloyloxyethyl-o-phthalate, 2.1 parts by mass of 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, Add 0.33 parts by mass of N, N'-tetraethyl-4,4'-diaminobenzophenone, 0.25 parts by mass of mercaptobenzimidazole, 8 parts by mass of (3-methacryloylpropyl) trimethoxysilane and 30 parts by mass of methyl ethyl ketone. Was mixed for 15 minutes to prepare a lens member-forming resin composition solution.

A polyethylene terephthalate film having a thickness of 16 μm was used as a support film, and the resin composition solution for forming a lens member obtained above was uniformly applied on the support film using a comma coater, and a hot air convection dryer at 100 ° C. And dried for 3 minutes to remove the solvent and form a lens member-forming resin layer. In this embodiment, the thickness of the lens member-forming resin layer (film) used is described in the embodiment. The film thickness of the lens member forming resin layer described in the examples is the film thickness after coating and drying.
Next, a polyethylene terephthalate film having a thickness of 25 μm was further bonded as a protective film on the obtained resin layer for forming a lens member to produce a lens member forming resin layer.

<Production of lens sheet>
The protective film of the 10 μm-thick position-recognition marker-forming resin layer is peeled off, and a 150 mm × 150 mm polyimide film (polyimide; Upilex RN (manufactured by Ube Nitto Kasei Co., Ltd.), thickness: 25 μm) is used as a roll laminator ( Hitachi Chemical Technoplant Co., Ltd., HLM-1500) was used for thermocompression bonding under conditions of a pressure of 0.4 MPa, a temperature of 70 ° C., and a laminating speed of 0.2 m / min.

Next, ultraviolet light (wavelength 365 nm) is 0.3 J from the support film side through a negative photomask on which the shape of the position recognition marker is drawn by an ultraviolet exposure machine (model name: EXM-1172, manufactured by Oak Manufacturing Co., Ltd.). / Cm ² irradiation. The shape and position of the position recognition marker will be described later.
Next, the protective film of the resin layer for forming the position recognition marker is peeled off, and the resin layer for forming the lens member having a thickness of 30 μm obtained above is protected on the exposed resin surface of the resin layer for forming the position recognition marker. The resin surface from which the film was peeled was thermocompression bonded in the same manner as described above.

Next, UV light (wavelength 365 nm) is 0.3 J from the support film side through a negative photomask on which the planar shape of the plano-convex lens is drawn by an ultraviolet exposure machine (model name: EXM-1172, manufactured by Oak Manufacturing Co., Ltd.). / Cm ² irradiation. The shape and position of the plano-convex lens will be described later. Thereafter, the support film was peeled off and etched using a 1.0% by mass aqueous solution of potassium carbonate to form a position recognition marker 5 and a laminate of the position recognition marker and the lens forming member. Then, it heated at 180 degreeC for 1 hour, the lens formation member was dripped, the planoconvex lens 1 was formed, and the lens sheet which consists of an organic compound which has flexibility was produced.

The obtained lens sheet includes four plano-convex lenses 1 arranged on a sheet at a pitch of 250 μm, and a position recognition marker 5 (height 10 μm) of 100 μm × 100 μm at a position 100 μm outside the plano-convex lens 1 on both sides. A lens sheet having 10 units at a 5 mm pitch in the plano-convex lens arrangement direction and 10 units at a 5 mm pitch in the direction perpendicular to the arrangement direction of the plano-convex lenses 1 was produced. The design value of the diameter of the bottom surface was 150 μm (diameter size tolerance ± 2 μm), and the deviation tolerance from the design value from the position recognition marker was ± 5 μm.
The plano-convex lens 1 is formed on a cylindrical pattern made of the same material as that of the position recognition marker 5. However, in this embodiment, they are treated as a plano-convex lens in which they are integrated and are not shown in the drawing.

[Measurement of reference sample]
A quartz glass with a thickness of 3 mm is applied as a transparent plate 8 to the flat surface side of a reference sample that has been confirmed to be a non-defective product in the same shape as the unit obtained above, and at a position that does not interfere with the plano-convex lens R and the position recognition marker. It pressed from the opposite direction to quartz glass using the pressing tool which has an opening part.

Next, the inspection light source 6 (wavelength; 850 nm) of the optical tester (product name: OPT-002, manufactured by Synergy Opto Systems Co., Ltd.) and the inspection light receiving unit 7 (CCD) are coaxially opposed, and the inspection light source 6 side is A plano-convex lens R is inserted between the inspection light source 6 and the inspection light receiving unit 7 with the quartz glass surface side, and is fixed to a sample stage movable in the XYZ directions (the sample stage is connected to the inspection light source 6 and the inspection light receiving unit 7). Move independently). The distance (gap) between the inspection light source 6 and the quartz glass was 15 mm, and the inspection light receiving unit 7 was disposed at a position where the lower surface of the position recognition marker 5 (the junction between the position recognition marker 5 and the sheet 4) is in focus. Next, the inspection light source 6 is moved in the plane parallel direction of the lens sheet, and adjusted to a position (center of the spot diameter) where the intensity of light transmitted through the plano-convex lens R is large and insensitive to the displacement of the inspection light source 6 position. did. The inspection light receiving unit 7 is adjusted to a position where the plano-convex lens R can be recognized at the center of the image.
Next, the incident light of red light was irradiated from the inspection light receiving unit 6 side, and the size and position of the position recognition marker 5 and the bottom surface of the plano-convex lens R were measured. Next, the inspection light source 6 was turned on, and the total luminance observed by being included in the bottom surface of the plano-convex lens R was measured.

Next, with the inspection light source 6 turned on, the sample stage was moved to the inspection light source 6 side by 100 μm as the first distance α to obtain an image of the image. A portion where the intensity of the image is 50% of the maximum intensity is defined as an image formation region. As a result, the image formation size was 100 μm in diameter. As the second distance α, the sample stage was further moved to the inspection light source 6 side by 50 μm to obtain an image of the image. As a result, the image size was 80 μm in diameter. The deviation from the design value of the imaging position ρ from the position recognition marker 5 was 0 μm. There was no distortion of the imaging circle.

[Installation of measurement sample]
Next, quartz glass having a thickness of 3 mm is applied as the transparent plate 8 to the flat surface side of the previously formed lens sheet, and an opening is formed at a position that does not interfere with the plano-convex lens 1 and the position recognition marker 5. It pressed from the opposite direction to quartz glass using the holding tool which has.
Next, the inspection light source 6 (wavelength; 850 nm) of the optical tester (product name: OPT-002, manufactured by Synergy Opto Systems Co., Ltd.) and the inspection light receiving unit 7 (CCD) are coaxially opposed to each other, and the inspection light source 6 side The plano-convex lens 1 is inserted between the inspection light source 6 and the inspection light receiving unit 7 with the quartz glass surface side, and fixed to the sample stage movable in the XYZ directions (the sample stage is the inspection light source 6 and the inspection light receiving unit 7). Move independently). At this time, since the lens sheet can be handled integrally with the quartz glass, it can be easily attached to the sample stage. Further, the distance between the inspection light source 6 and the quartz glass was 15 mm, and the inspection light receiving unit 7 was arranged at a position where the lower surface of the position recognition marker 5 was in focus. At this time, the positional relationship between the inspection light source 6 and the inspection light receiving unit 7 is fixed at the position where the previous plano-convex lens R is measured, and the inspection light receiving unit 7 (CCD) has a plano-convex lens (4) at the center of the image. The position is adjusted so that it can be recognized. Note that the inspection light source 6 and the inspection light receiving unit 7 are provided with a lens or the like (not shown) for controlling the angle of incident light or acquiring a formed image.

[Measurement of measurement sample]
Next, the incident light of red light was irradiated from the side of the inspection light receiving unit 7 to measure the size and position of the position recognition marker 5 and the bottom surface of the plano-convex lens (the inspection light source 6 and the inspection light receiving unit 7 are , Position 605 (705) shown in FIG. 3 with respect to the lens sheet). Regarding the size of the bottom surface of the lens, a diameter in the range of 148 μm to 152 μm was good, and the others were bad. Further, the total luminance observed in the bottom surface of the plano-convex lens R measured previously is 100%, and the total luminance observed in the bottom surface of the plano-convex lens to be measured is 95% or higher. Defective.

Next, with the inspection light source 6 turned on, the sample stage is moved to the inspection light source 6 side by 100 μm as the first distance α to obtain an image of the image (the inspection light source 6 and the inspection light receiving unit 7 are formed on the lens sheet) (Position 601 (701) shown in FIG. 3). A portion where the intensity of the image is 50% of the maximum intensity is defined as an image formation region. As a result, the image formation size was good when the diameter was in the range of 98 to 102 μm, and the others were bad. Further, the total brightness of the image of the plano-convex lens R at the first distance α is 100%, the total brightness of the image of the plano-convex lens 1 to be measured is 95% or higher, and the lower is bad. As the second distance α, the sample stage was further moved to the inspection light source 6 side by 50 μm to obtain an image of the image. As a result, the image formation size was good when the diameter was in the range of 78 to 82 μm, and the others were bad. Further, the total brightness of the image of the plano-convex lens R at the second distance α is set to 100%, the total brightness of the image of the plano-convex lens 1 to be measured is 95% or higher, and the lower is determined to be poor. Regarding the deviation from the design value of the imaging position β from the position recognition marker 5, the deviation amount from the design value is good within ± 5 μm, and the other is bad. Also, the image with circular distortion was regarded as defective. If there is at least one defective plano-convex lens 1 in the unit, the unit is regarded as defective.

[Continuous measurement of measurement sample]
Next, in order to measure adjacent units, the sample stage is moved so that the inspection light source 6 is moved relative to the sheet surface 4 of the lens sheet in the parallel direction 610 (the inspection light receiving unit is also in the same direction 710). I let you. Thereafter, the plano-convex lens 1 (unit) was inspected by the same method as in [Measurement of measurement sample].

Thereafter, the sample stage is sequentially moved (as shown in FIG. 3, the inspection light source 6 and the inspection light receiving unit 7 are sequentially moved to positions 602 (702), 603 (703), and 604 (704)), and 10 rows × 10 A row of plano-convex lenses 1 (units) was inspected. The inspection could be efficiently performed only by moving the sample stage, acquiring images, and judging.

Example 2
A reflection plate 9 was formed by depositing Au of 0.5 μm on one surface of the quartz glass which is the transparent plate 8 used in Example 1.
Next, the flat surface 3 of the lens sheet is applied to the non-deposition surface side of the quartz glass in the same manner as in Example 1, and the quartz glass is used by using a pressing tool having an opening at a position that does not interfere with the plano-convex lens R and the position recognition marker 5. Pressed from the opposite direction to the glass.

[Measurement of reference sample]
Next, an inspection light receiving unit (CCD) is placed in the center of the ring illumination of the inspection light source (wavelength: 850 nm) of the optical tester (product name: OPT-002, manufactured by Synergy Opto Systems Co., Ltd.), and inspection is performed. The light source 6 side was set on the convex portion side of the plano-convex lens R. The lens sheet was fixed to a sample stage movable in the XYZ directions (the sample stage is movable independently of the inspection light source and the inspection light receiving unit). At this time, since the lens sheet can be handled integrally with the quartz glass with the reflecting plate 9, it can be easily attached to the sample stage. The distance between the inspection light source 6 and the reflecting plate 9 was 12 mm, and the inspection light receiving unit 7 was disposed at a position where the lower surface of the position recognition marker 5 was in focus. Next, the inspection light source 6 and the inspection light receiving unit 7 are moved in the plane parallel direction of the lens sheet, and the intensity of light transmitted through the plano-convex lens R (light received by the inspection light receiving unit) is large. It adjusted to the position (center of a spot diameter) insensitive to a position shift. The inspection light receiving unit 7 is adjusted to a position where the plano-convex lens R can be recognized at the center of the image. Next, the incident light of red light was irradiated from the inspection light receiving unit 7 side, and the size and position of the position recognition marker 5 and the bottom surface of the plano-convex lens R were measured. Next, the inspection light source 6 was turned on, and the total luminance observed by being included in the bottom surface of the lens R was measured.

Next, with the inspection light source 6 turned on, the sample stage was moved to the inspection light source 6 side by 100 μm as the first distance α to obtain an image of the image. A portion where the intensity of the image is 50% of the maximum intensity is defined as an image formation region. As a result, the image formation size was 100 μm in diameter. As the second distance α, the sample stage was further moved to the inspection light source 6 side by 50 μm to obtain an image of the image. As a result, the image size was 80 μm in diameter. The deviation from the design value of the imaging position ρ from the position recognition marker 5 was 0 μm. There was no distortion of the imaging circle.

[Installation of measurement sample]
Next, quartz glass with a reflector 9 having a thickness of 3 mm is applied to the flat surface 3 side of the lens sheet, which is a measurement sample produced by the same method as in Example 1, and the planoconvex lens 1 and It pressed from the opposite direction to quartz glass using the pressing tool which has an opening part in the position which does not interfere with the position recognition marker 5. FIG.

Next, it was fixed to the sample stage movable in the XYZ directions by the same method as described above (the sample stage is movable independently of the inspection light source and the inspection light receiving unit). At this time, since the lens sheet can be handled integrally with the quartz glass with a reflecting plate, it can be easily attached to the sample stage. At this time, the positional relationship between the inspection light source 6 and the inspection light receiving unit 7 is fixed at the position where the plano-convex lens R is measured, and the plano-convex lens 1 (one unit) is centered on the image by the inspection light receiving unit 7 (CCD). 4 positions) are adjusted to a recognizable position.

[Measurement of reference sample]
The lens sheet was inspected by the same method and criteria as in Example 1 and above. As a result, non-defective product determination was possible. The inspection could be efficiently performed only by moving the sample stage, acquiring images, and judging.

Example 3
Next, the core pattern is 4CH (250 μm pitch), a cladding layer in which the core pattern is embedded, and an optical waveguide with a mirror including four optical path conversion mirrors arranged in the direction perpendicular to the core pattern on the optical axis of the core pattern, The lens sheet (unit) determined as a non-defective product obtained in Example 1 and the optical path conversion mirror are aligned, and a transparent heat having a thickness of 10 μm is formed so that the flat surface 3 side of the lens sheet becomes an optical waveguide with a mirror. When combined through a cured adhesive sheet, each plano-convex lens 1 and all the optical path conversion mirrors can be satisfactorily aligned, and sequentially through the core pattern, the optical path conversion mirror and the lens, or the lens, the optical path conversion mirror, and Light was able to propagate well through the core pattern sequentially.

Example 4
Next, four wirings for mounting optical elements were formed on the FR-4 substrate, and an electric wiring board having four openings (250 μm pitch) with a diameter of 100 μm was prepared. The non-defective product obtained in Example 1 The convex surface side of the plano-convex lens 1 through the lens sheet (unit) determined to be 50 μm thick thermosetting adhesive sheet (with the plano-convex lens portion opened), and the surface opposite to the electrical wiring for mounting the optical element Are combined so that each of the plano-convex lenses 1 and all the openings can be satisfactorily aligned, and a light receiving element having four light receiving parts (250 μm pitch) is mounted on the electric wiring for mounting the optical element. However, light was able to propagate well to the light receiving element through the plano-convex lens and the opening at all four locations. Next, when the light emitting element having four light emitting portions (250 μm pitch) is mounted on the electric wiring for mounting the optical element, the light from the light emitting element is satisfactorily transmitted through the opening and the plano-convex lens 1 at all four locations. Was able to propagate.

According to the present invention, it is possible to provide a method capable of simply and efficiently inspecting a lens. Therefore, it can be applied to a wide range of fields such as a microlens array, a lens sheet, an optical waveguide with a lens, an electrical wiring board with a lens, a photoelectric conversion member with a lens, an optical transmission module, an optical transmission line cable, and an optical interconnection.

DESCRIPTION OF SYMBOLS 1 Plano-convex lens 2 Plane-convex lens bottom face 3 Flat part 4 Sheet 5 Position recognition marker 6 Inspection light source 601, 602, 603, 604, 604 Position at the time of image formation measurement of inspection light source 605 Position at the time of starting measurement of the distance α of the inspection light source 7 Inspection light receiving unit 701, 702, 703, 704, 704 Position 705 at the time of imaging measurement of the inspection light receiving unit 8 Position at the time of starting measurement of the distance α of the inspection light receiving unit 8 Transparent plate 9 Reflecting plate 10 Inspection light 110 Connection Images 111, 112, 113, 114 Imaging (example of defective mode)
115 Imaging position (distance α)

Claims (18)

1. A method for inspecting a lens sheet in which a lens is formed on at least a part of the sheet,
   Step A for injecting inspection light into the lens,
   At least one selected from light intensity, size, shape, and position β of substantial imaging of the inspection light through the lens at an arbitrary distance α in the thickness direction of the lens sheet from the bottom surface of the lens Measuring step B,
   Step C for determining the quality of the lens from the measurement result,
   A method for inspecting a lens sheet.
2. The inspection of the lens sheet according to claim 1, wherein the inspection light source that outputs inspection light in the step A and the inspection light receiving unit that measures the inspection light in the step B inspects the lens sheet in a non-contact manner. Method.
3. 3. The method for inspecting a lens sheet according to claim 1, wherein a spot diameter of the inspection light on a bottom surface of the lens is a size including the diameter of the lens.
4. The method for inspecting a lens sheet according to any one of claims 1 to 3, wherein, in the step A, a transparent substrate is installed on a sheet surface opposite to a surface on which the lens is formed before the inspection light is incident.
5. The method for inspecting a lens sheet according to claim 4, wherein, in the step A, the inspection light is incident through the transparent substrate.
6. In the step A, before entering the inspection light, a reflecting plate is installed above the sheet surface opposite to the surface on which the lens of the sheet is formed, and the inspection light is incident from the surface side on which the lens is formed. And
   6. The method for inspecting a lens sheet according to claim 1, wherein in the step B, the measurement is to measure light reflected by the reflecting plate through the lens.
7. The method for inspecting a lens sheet according to claim 6, wherein the reflecting plate is installed in parallel with the sheet surface.
8. A step D in which at least two or more position recognition markers are installed at locations other than the lens on the lens sheet, and the relative positional relationship between the positions of the at least two position recognition markers and the imaging position β is measured; The lens sheet inspection method according to claim 1, further comprising:
9. The lens sheet inspection method according to claim 8, wherein the position recognition marker is a reference position for determining an arbitrary distance α in the thickness direction of the lens sheet.
10. At least one selected from light intensity, size, shape, and position ρ of substantial imaging of the inspection light through the lens at an arbitrary distance α in the thickness direction of the lens sheet from the bottom surface of the lens Further comprising a step E of measuring at least one of the data for a lens R whose data is known;
    The method for inspecting a lens sheet according to any one of claims 1 to 9, wherein the step C for determining the quality of the lens determines the quality of the lens to be inspected from a comparison of the measurement data in the steps E and B. .
11. The method for inspecting a lens sheet according to any one of claims 1 to 10, further comprising a step F of measuring a diameter of the lens.
12. 12. The positional relationship between an inspection light source that outputs inspection light in the step A and an inspection light receiving unit that measures the inspection light in the step B is defined in the sheet plane direction. A method for inspecting a lens sheet according to claim 1.
13. 2. The process A and the process B are performed by continuously or intermittently inspecting a plurality of lenses by moving at least the inspection light receiving unit in a direction parallel to the sheet surface. The method for inspecting a lens sheet according to any one of items 1 to 12.
14. A lens sheet inspected by the lens sheet inspection method according to any one of claims 1 to 13.
15. The lens sheet according to claim 14, wherein at least a part of the lens sheet on the lens optical axis is made of an organic compound.
16. The lens sheet according to claim 14 or 15, wherein the lens sheet has flexibility.
17. An optical waveguide with a lens, wherein the lens sheet according to any one of claims 14 to 16 and an optical waveguide with a mirror are combined.
18. An electric wiring board with a lens, wherein the lens sheet according to any one of claims 14 to 16 and an electric wiring board are combined.

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