JP6488864B2 - Method for manufacturing optical transmitter array - Google Patents

Description

  The present invention relates to a method for manufacturing an optical transmitter array, and more particularly, to a method for manufacturing an optical transmitter array in which cylindrical rod lenses are arranged in parallel between two substrates.

  Conventionally, a cylindrical rod lens whose both end surfaces are mirror-polished is known as one of microlenses. In addition to being used alone, such a rod lens is in the form of a rod lens array in which a large number of rod lenses are arranged and integrated, and is used in a copying machine, facsimile, scanner, hand scanner, etc. Used as a light transmission body for writing, or as an optical transmission body for writing in devices such as LED printers using LEDs (light emitting diodes) as light sources, liquid crystal printers using liquid crystal elements, and EL printers using EL elements ing.

  Such a rod lens array is manufactured by, for example, a method disclosed in Patent Document 1. Two substrates are prepared, an adhesive is applied on one of the substrates, a rod lens is arranged thereon, and then the other substrate on which the adhesive is applied is placed on the surface. Thereafter, the bonded rod lens array original plate is obtained by curing the adhesive, and then the rod lens array original plate is cut so as to have a predetermined lens length, and both end surfaces of the obtained rod lens array are mirror-polished.

JP 2008-65318 A

However, when a rod lens array original plate is manufactured by the manufacturing method as described above using a thin lens that has recently become widespread, an air pocket may be formed in the adhesive layer. The end surface of the rod lens cut out from the rod lens array original plate may be exposed as a “dent”. If such a dent occurs, the rod lens will be chipped at the dent when cutting the rod lens array master plate, or the polishing buff will be caught when polishing the end surface of the rod lens array. In some cases, the lens performance is deteriorated and the final yield of the rod lens is deteriorated. Here, in patent document 1, although the technique which suppresses generation | occurrence | production of an air pocket is disclosed by optimizing the quantity of the adhesive agent to apply | coat, although generation | occurrence | production of an air pool can be suppressed with these techniques, As is apparent from the examples and comparative examples of Patent Document 1, it has been difficult to provide a rod lens that is completely free of air accumulation.

The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a high-quality rod lens array that suppresses the occurrence of a dent as described above.
According to the present invention, there is provided a method of manufacturing an optical transmitter array in which a plurality of cylindrical optical transmitters are arranged in parallel between a first substrate and a second substrate,
A first application step of applying a first adhesive to the surface of the first substrate;
A plurality of the optical transmission bodies are arranged in parallel, the optical transmission bodies arranged in parallel are brought into contact with the first adhesive applied to the first substrate, and the optical transmission bodies are attached to the first substrate. A first bonding step;
A second application step of applying a plurality of parallel strips of the second adhesive on the surface of the second substrate;
The second adhesive applied to the second substrate and the optical transmission body attached to the first substrate extend from the second adhesive having a strip-shaped central axis of the optical transmission body. A second bonding step of bringing the first substrate, the optical transmission body, and the second substrate into contact with each other so as to be orthogonal to a direction to obtain an optical transmission body array original plate;
Cutting the optical transmitter array original plate to obtain an optical transmitter array, and
Each of the bands of the second adhesive applied in the two application steps is
The cross-sectional shape in the direction perpendicular to the direction in which the band extends is a shape in which the width continuously decreases in the direction away from the second substrate, and the maximum value of the width is 0.8 mm or more and 2.0 mm or less. And the height of the cross section is not less than 100 μm and not more than 250 μm.
A method of manufacturing an optical transmitter array is provided.

As a result of intensive studies, the present inventors have found that the above-described air pocket is likely to occur on one of the two substrates of the optical transmission array. Then, as a result of further intensive studies, it was found that one of the causes of the indentation is the application shape of the second adhesive applied to the second substrate. That is, if the shape of the tip of the second adhesive applied to the second substrate is inwardly recessed, there is no escape at the time of bonding between the substrate and the optical transmission body, so air is caught and the air A pool is formed.

In the present invention configured as described above, the cross-sectional shape in the direction orthogonal to the direction in which the second adhesive row extends is a shape in which the width continuously decreases in the direction away from the second substrate. For this reason, when bonding the second substrate and the optical transmission body, air is not caught between the adhesive and the optical transmission body. For this reason, in manufacturing the optical transmitter array original plate, it is possible to suppress air accumulation.

  According to an embodiment of the present invention, in the cutting step, the optical transmitter array original plate is cut in parallel with a direction in which the columns extend at the application position of the second adhesive to obtain an optical transmitter array. A method of manufacturing an optical transmitter array is provided.

  According to another embodiment of the present invention, there is provided an optical transmitter array having no air pocket between the first substrate and the second substrate and the optical transmitter.

  As described above, according to the present invention, there is provided a method for manufacturing a rod lens array that can stably manufacture a high-performance rod lens array with a high yield.

It is a schematic perspective view which shows the rod lens array original plate manufactured with the rod lens array manufacturing method of preferable embodiment of this invention. It is a side view which shows roughly the structure of the adhesive agent coating apparatus of this embodiment. It is a disassembled perspective view of an adhesive discharge nozzle. Shim shape in the adhesive discharge nozzle It is sectional drawing to which the discharge nozzle of the adhesive agent coating apparatus of FIG. 2 was expanded. It is a perspective view which shows typically the state of the 1st adhesive agent apply | coated to the surface of the 1st board | substrate by the 1st application | coating process. It is typical sectional drawing which shows the relationship between the diameter of a rod lens, and the thickness of a 1st adhesive agent, when the rod lens of diameter D is pressed and adhered to the surface of the 1st board | substrate which apply | coated the adhesive agent. It is drawing for demonstrating the calculation method of the thickness of an adhesive agent. It is a typical perspective view which shows the state in which a rod lens is accommodated in the lens alignment groove | channel of an arrangement | sequence plate. It is a perspective view which shows typically the state of the 2nd adhesive agent apply | coated to the surface of the 2nd board | substrate by the 2nd application | coating process. It is the application | coating cross-sectional shape of the 2nd application | coating process in an Example. It is the application | coating cross-sectional shape of the 2nd application | coating process in a comparative example.

  A manufacturing method of a rod lens array (optical transmission body array) according to a preferred embodiment of the present invention will be described in detail with reference to the drawings. First, the structure of the rod lens array manufactured by the rod lens array manufacturing method according to a preferred embodiment of the present invention will be described. FIG. 1 is a schematic perspective view showing a rod lens array original plate 1 manufactured by a rod lens array manufacturing method according to a preferred embodiment of the present invention.

  As shown in FIG. 1, in the rod lens array original plate (optical transmitter array original plate) 1, a large number of rod lenses 6 are arranged in parallel between the first and second substrates 2 and 4. Yes. A space between the substrates 2 and 4 and each rod lens 6 is an adhesive layer 8, and each rod lens 6 is fixed between the substrates 2 and 4 by the adhesive layer 8. As the substrates 2 and 4, plates such as bakelite (phenol resin), ABS resin, epoxy resin, and acrylic resin containing a light shielding agent such as carbon black and dye are used.

The rod lens 6 is a lens element that is made of cylindrical plastic or glass, has a refractive index that continuously decreases from the central axis toward the outer periphery, and forms an erect life-size image. The refractive index distribution is a refractive index distribution in the range of 0.3r to 0.7r at least from the central axis toward the outer periphery when the radius of the rod lens is r in a cross section perpendicular to the central axis of the rod lens. It is preferable to approximate to a quadratic curve distribution defined by the following formula.
_{n (L) = n 0 {} 1- (g 2/2) L 2}
(Where n ₀ is the refractive index (central refractive index) at the central axis of the rod lens, L is the distance from the central axis of the rod lens (0 ≦ L ≦ r), and g is the refractive index of the rod lens. (It is a distribution constant, and n (L) is a refractive index at a position of a distance L from the central axis of the rod lens.)

  As shown by the dotted line in FIG. 1, such a rod lens array original plate 1 has a position of the adhesive, preferably along the direction perpendicular to the rod lens 6, that is, the direction in which a plurality of strips of strip-shaped applied adhesive extend. The rod lens array is manufactured by cutting at the center position.

  Next, the configuration of the adhesive application device used in a preferred embodiment of the present invention will be described. FIG. 2 is a side view schematically showing the configuration of the adhesive application device 10 of the present embodiment.

  As shown in FIG. 2, the adhesive application device 10 includes an adhesive charging pot 12 in which an adhesive is accommodated, an adhesive discharge dispenser gun 14, and an adhesive discharge nozzle 16. The adhesive dispensing dispenser 14 communicates with the adhesive charging pot 12 and supplies the adhesive in the adhesive charging pot 12 to the adhesive discharging nozzle 16. The adhesive discharge nozzle 16 is disposed below the adhesive charging pot 12 with the discharge port 16a facing downward via the nozzle mounting plate 18.

  A holding plate 22 is disposed below the adhesive discharge nozzle 16. The upper surface of the holding plate 22 is a substrate placement surface 22a, and the substrate 2 (4) constituting the rod lens array original plate 1 is placed on the substrate placement surface 22a. The discharge port 16a of the adhesive discharge nozzle 16 is disposed so as to face the substrate placement surface 22a. The substrate holding surface 22a is preferably made of an elastic material. In the present embodiment, the substrate holding surface 22a is formed of silicon rubber having an appropriate elasticity.

  Further, the adhesive application device 10 is configured such that the tip of the adhesive discharge nozzle 16 is placed and fixed on the substrate holding surface 22a during application of the adhesive by a pressing mechanism (not shown) such as a spring mechanism. ) It is configured to contact the surface (application surface). For this reason, even when the thickness of the substrate 2 (4) is uneven, the adhesive is applied to the coating surface of the substrate 2 (4) with a uniform thickness.

  The adhesive application device 10 includes a drive mechanism (not shown) capable of adjusting the speed for moving the adhesive discharge nozzle 16 and the holding plate 22 relative to each other. As a drive mechanism, a drive mechanism for moving the moving stage on which the holding plate 22 is placed with respect to the stationary adhesive discharge nozzle 16, or an adhesive charging pot 12, an adhesive discharge dispenser gun 14, and an adhesive A drive mechanism or the like is employed in which the discharge nozzle 16 and the like are attached to a moving stage and moved with respect to the stationary holding plate 22.

  Next, the structure of the adhesive discharge nozzle 16 will be described in detail. 3 is an exploded perspective view of the adhesive discharge nozzle 16, FIG. 4 is an enlarged view of the shape of the shim in the discharge nozzle, and FIG. 5 is an enlarged view of the discharge port 16a of the adhesive discharge nozzle 16 of FIG. It is a longitudinal cross-sectional view.

As shown in FIG. 3, the adhesive discharge nozzle 16 includes two base members 26, 28 and a shim 20 having a specific thickness disposed between the base members 26, 28. . The groove of the discharge portion of the shim is a shape as shown in FIG. 4, it is possible to adjust the application shape by adjusting the depth of the groove (u ₁₎ and width (u _2). At this time, if the depth (u ₁ ) is 0.5 mm to 1.8 mm in width, the applied adhesive can have a cross-sectional shape as described later, and preferably 0.8 mm to 1.5 mm. The width (u ₂ ) is 300 to 400 μm, preferably 320 to 360 μm. By setting the width (u ₂ ) within the above range, the applied adhesive can have a cross section as described later.

  As shown in FIG. 3, the base members 26 and 28 are both thick plate members whose lower ends taper in a wedge shape, and are disposed to face each other. The shim 20 is a plate-like member, and the adhesive can be discharged into a plurality of strips (multiple strips) by a plurality of slits 20b formed at the tip (lower end). The base members 26 and 28 are connected and integrated by a connecting mechanism (not shown) with the shim 20 sandwiched therebetween.

  The adhesive enters the cutout portion 20a of the shim 20 through the cutout portion 28a of the cap member 28 from the inflow passage 16b penetrating the base member 28, and enters the substrate 2 (4) from the opening portion of the discharge port 16a. It will be discharged toward.

  In order to change the application state of the adhesive, it is possible to use a shim 20 having a different shape. In this embodiment, the shim 20 having a different shape of the slit 20b is also used to the substrate 2 (4). The application state of the adhesive can be changed. In the shim 20 shown in FIG. 3, the adhesive can be discharged and applied as five strips with a predetermined interval.

  The shim 20 may not be disposed between the base members 26 and 28, and the discharge port width d1 may be maintained by the base members 26 and 28 alone. For example, when there is little change in the type of rod lens array to be manufactured, the thickness of the adhesive is not frequently changed, and the moving speed of the adhesive applicator 10 or the discharge of the adhesive from the adhesive discharge nozzle 16 is performed. It is only necessary to finely adjust the cross-sectional shape of the adhesive by adjusting the pressure or the like. In this case, a step may be provided in the longitudinal direction on the opposing inner surfaces of the base members 26 and 28 so as to have a preset outlet width d1.

As shown in FIG. 5, the two base members 26, 28 are assembled so that the height positions of the tips (lower ends) differ by a level difference h ₁ . Specifically, the lower end (tip) of the base member 28 disposed on the downstream side in the application direction of the adhesive discharge nozzle 16 and the substrate 2 (4) abuts on the application surface of the substrate 2 (4), and the application direction is reduced. the lower end of the base member 26 disposed on the upstream side (front end) is configured so as to be positioned above the lower end of the base member 28 (distal end) by the step h _1.

According to such a configuration, by changing the step h _1, the dimensions (length in the vertical direction) is changed in the discharge port 16a, the adhesive discharge amount or adhesive application amount from the discharge port 16a is changed . Therefore, by changing the step h _1, it can alter the adhesive discharge amount from the discharge port 16a, to adjust the thickness of the adhesive applied to the substrate 2 (4).

  In the present embodiment, a low friction coating such as DLC (Diamond, Like, Carbon) is applied to the tip surface of the adhesive discharge nozzle 16. With such a configuration, the frictional resistance can be reduced even if the tip end surface of the nozzle comes into contact with the substrate 2 (4), so that the substrate 2 (4) is prevented from being damaged, and the contact causes the base member It is also suppressed that the lower end of 28 is damaged.

  Next, the adhesive application process by the adhesive application device of this embodiment will be described. First, a predetermined amount of moisture-curing adhesive is charged into the adhesive charging pot 12 and delivered into the adhesive dispensing dispenser gun 14.

  Delivery of the adhesive to the dispenser gun 14 for discharging adhesive is performed by introducing compressed air, inert gas, or the like into the adhesive charging pot 12. In the adhesive application device 10 of this embodiment, the pressure of the gas introduced into the adhesive charging pot 12 may be in a range that can maintain a predetermined discharge amount, preferably 0.05 to 1 MPa, more preferably 0. The range is from 10 to 0.7 MPa.

If this pressure is too high, the adhesive charging pot 12 and the like must be configured with a pressure vessel,
In addition, in order to maintain a high pressure, it is necessary to install a compressor or the like, and the adhesive application device has a complicated structure, which results in a large-scale device and an increase in cost. On the other hand, if the pressure is too low, it becomes difficult to maintain a predetermined discharge amount.

  In addition, since the viscosity of the adhesive is high and the adhesive may not be sufficiently delivered to the dispenser gun 14 for discharging the adhesive by simply pressurizing the inside of the adhesive charging pot 12, the adhesive charging pot 12, adhesive The agent discharge dispenser gun 14, the adhesive discharge nozzle 16, and the nozzle mounting plate 18 are preferably configured to be heated to 80 to 120 ° C. as appropriate. The viscosity of the adhesive is preferably 2500 to 5000 [cP] when heated, and more preferably 3000 to 4000 [cP].

The adhesive dispenser gun 14 is opened and closed by an air source (not shown),
An adhesive is supplied to the adhesive discharge nozzle 16. Instead of the dispenser gun 14 for discharging the adhesive, a configuration may be used in which the adhesive is sent to the adhesive discharge nozzle 16 using a gear pump or the like.

  In the adhesive application device 10 of the present embodiment, the base member 28 is pressed against the surface of the substrate 2 (4) placed on the holding plate 22, and the adhesive is discharged from the discharge port 16 a of the adhesive discharge nozzle 16. The adhesive discharge nozzle 16 and the holding plate 22 are moved relative to each other, and the adhesive is sequentially applied to the surface of the substrate 2 (4) from the upstream side to the downstream side in the application direction indicated by the arrow A in FIG. Apply.

  The relative movement speed of the adhesive discharge nozzle 16 and the holding plate 22, which is the application speed of the adhesive to the substrate 2 (4), is preferably in the range of 1 to 250 mm / sec, more preferably 20 to 100 mm / sec. .

  When the adhesive is applied while the base member 28 is in contact with the surface of the substrate 2 (4) as in the present embodiment, the adhesive is applied with the substrate 2 (4) placed on a plate having no elasticity. In this case, the adhesive discharge nozzle 16 biased toward the substrate jumps up, the thickness of the adhesive is not uniform, and uneven coating may occur. However, in the present embodiment, since the substrate holding surface 22a has elasticity, the above-described jumping of the adhesive discharge nozzle 16 is prevented.

Next, the manufacturing method of the rod lens array (optical transmission body array) of preferable embodiment of this invention is demonstrated in detail along drawing.
First, a first application process for applying a first adhesive to the surface of the first substrate 2 is performed. In the first application step, as shown in FIG. 6, the first adhesive 30 is applied to almost the entire surface of the first substrate 2 using, for example, the adhesive application device 10 described above, and the gap S <b> 1 is 0. .5 to 2 mm, preferably 0.5 to 1.5 mm, with a pitch P (that is, P = W1 + S1 = rod lens length L + cutting margin), a plurality of strips are applied in a strip shape extending in the width direction of the substrate 2. . The cutting allowance is preferably 0.4 to 0.6 mm. In order to obtain a large number of rod lens arrays, the shorter one is preferable, and the longer one is preferable in that the strength can be ensured by thickening the blade.

  In the case of manufacturing a lens having a total length of 3 mm or more, it is preferable to set this width because the warping of the substrate can be suppressed and the filling amount of the adhesive and the clearance allowance can be secured. The adhesive may be applied to the surface of the substrate in a surface shape instead of a belt shape, or instead of applying the adhesive, an adhesive sheet may be placed so as to cover the entire surface of the substrate.

  The thickness Z11 at the time of application of the first adhesive 30 is as shown in FIG. 8 when the rod lens 6 having a diameter D is pressed and adhered to the surface of the first substrate 2 to which the first adhesive 30 has been applied. It is preferable that the thickness Z12 of the first adhesive is set to be 0.5D to D.

A method of calculating Z11 will be described with reference to FIG. In the first application step, when the rod lens 6 having a diameter D is pressed and attached to the surface of the first substrate 2 to which the first adhesive 30 has been applied, the thickness of the first adhesive increases between the rod lenses 6. Therefore, when the rod lenses are pressed and adhered to the surface of the first substrate 2 in a state where the first adhesive 30 is uniformly applied to the surface, the thickness between the rod lenses 6 becomes equal to the radius of the rod lens 6 ( In other words, if the initial coating thickness is filled with a reference thickness Z ₅₀ (the space between adjacent rod lenses 6 is filled), the area of the adhesive before and after the rod lens attachment is equal in the cross-sectional view. The formula holds.
P × Z ₅₀ = D / 2 × P−1 / 2 × Π × (D / 2) ²
Here, the left side is the area of the adhesive before sticking the rod lens, and the right side is the area of the adhesive after sticking the rod lens.
Solving this for Z ₅₀ gives the following equation:

Actually, since the first adhesive 30 is applied to the first substrate 2 in a band shape, when the rod lens 6 is pressed, a part of the first adhesive 30 flows along the axial direction of the rod lens 6, preferably less than twice 1.1 or more Z ₅₀ is a coating thickness Z ₁₁ which space is filled between the rod lens 6 adjacent after pressing adhesion of the rod lens 6, and more is 1.5 times or less than 1.1 1.1 to 1.3 times is particularly preferable. Usually, a rod lens 6 having a diameter of 100 to 1000 μm is used.

Specifically, when the rod lens 6 having a diameter of 350 μm is used and the pitch is 360 μm (that is, the gap between adjacent rod lenses 6 is 10 μm), the reference thickness Z ₅₀ is 41 μm, so Z ₁₁ is 45 μm or more and 82 μm. Or less, more preferably 45 μm to 62 μm, and still more preferably 45 μm to 53 μm.

  By setting in this way, uneven arrangement of the rod lenses is suppressed. However, if the coating thickness of the first adhesive is too thick, the first adhesive will adhere to the flat plate with grooves for arranging a large number of rod lenses. Therefore, it is desirable to set an appropriate adhesive coating thickness.

  Next, as shown in FIG. 9, the plurality of rod lenses 6 are arranged in parallel by being accommodated in the plurality of lens alignment grooves 32 formed in parallel on the surface of the array plate 34, so that the first of the substrate 2 is arranged. Adhesive 30 is attached to the surface coated in a strip shape. The rod lenses 6 arranged in parallel are arranged so as to extend in a direction orthogonal to the direction in which the first adhesive 30 applied in a strip shape extends (that is, in the depth direction of the substrate), and are applied in a strip shape. It is pressed against the agent 30 and adhered to the first substrate 2 (first bonding step). In FIG. 9, the cross-section of the array groove is U-shaped, but it may be part of an arc regardless of whether it is V-shaped or U-shaped. It may be a flat surface without a groove.

  The gap between the rod lenses 6 arranged in parallel, that is, the gap between the lens alignment grooves 32 is preferably 1 to 20 μm, and more preferably 10 to 15 μm, in order to suppress poor filling of the adhesive and uneven arrangement when embedded.

  There are the following two methods for attaching the rod lenses 6 arranged in parallel to the arrangement plate 34 to the first substrate 2 coated with the first adhesive 30 while maintaining the arrangement state. One is an arrangement in which the first substrate 2 is arranged so that the surface on which the first adhesive 30 is applied is directed downward, and the lens alignment groove 32 accommodating the rod lens 6 is arranged upward. The plate 34 is pressed against the first substrate 2 from below, and the rod lens 6 is adhered to the first substrate 2 from the array plate 34. The other is the first substrate 2 coated with the first adhesive 30. The rod lens 6 is pressed from above to the first substrate 2 by placing the array plate 34 so that the lens alignment groove 32 accommodating the rod lens 6 faces downward. This is a method of adhering to the first substrate 2 from the array plate 34, and any method may be used. In the latter method, a mechanism for holding the rod lens 6 is provided in the lens alignment groove 32 of the alignment plate 34 so that the rod lens 6 does not fall from the lens alignment groove 32 even when the lens alignment groove 32 faces downward. ing.

  After the rod lens 6 is attached to the first substrate 2 to which the first adhesive 30 is applied, the first substrate 2 to which the rod lens 6 is attached is preferably at a temperature of 10 ° C. to 40 ° C. and a humidity of 20% RH. The first adhesive 30 may be sufficiently cured by leaving it in an environment of 85% RH, more preferably in an environment of room temperature 15 ° C. to 25 ° C. and humidity 30% RH to 60% RH for 8 to 50 hours. .

  Next, a second application process for applying the second adhesive to the surface of the second substrate 4 will be described. Here, as a result of examination by the inventors of the present application, it has been found that almost no air pool is generated on the first substrate side of the rod lens array, and an air pool is generated on the second substrate side. This is considered to be because when the first substrate 2 and the rod lens 6 are bonded, the second substrate is not bonded, so that there is a sufficient gap for removing the entrained bubbles. On the other hand, when the second substrate 4 is bonded, it is considered that an air pocket is generated between the rod lens 6 and the second substrate 4 because there is almost no space for the caught bubbles to escape. Therefore, in order to manufacture a rod lens array that is free of dents due to air pockets, it is necessary to strictly control the application shape of the second adhesive.

Specifically, using the above-described adhesive application device 10, the second adhesive 36 is applied to almost the entire surface of the second substrate 4 with a width W2 of 0.8 to 2.0 mm and a pitch P (that is, (P = W2 + gap S2 = L + cutting allowance) and a thickness Z2 of 100 to 250 μm, that is, a second application step of applying a plurality of strips extending in the width direction of the substrate 4 at the same pitch as the first application step. (FIG. 10). From the viewpoint of simplifying the manufacturing of the rod lens array, the description of the present embodiment describes the case where the application conditions of the adhesive of the first adhesive and the second adhesive are the same. Unlike the second adhesive, the application shape of the first adhesive need not be strictly controlled, and may be variously changed. A more preferable range of the application width W2 of the second adhesive is 0.9 to 1.8 mm, a further preferable range is 1.0 to 1.5 mm, and a more preferable range of the thickness Z2 is 130 to 230 μm. . When applied under this condition, the cross-sectional shape of each second adhesive band in the direction perpendicular to the direction in which each band of the second adhesive applied in a band shape is convex (that is, in the cross-sectional shape, (A shape in which the width continuously decreases in the direction away from the two substrates), and it is possible to suppress the accumulation of air in the manufactured rod lens array. In addition, the cross-sectional shape of the second adhesive may be any shape as long as the width continuously decreases toward the direction away from the second substrate in the above-described cross-sectional shape, such as a bell shape, a triangle, A shape such as a semicircle or a polygon folded in half may be used.

  Further, the surface of the second substrate 4 on which the second adhesive 36 is applied is pressed against the rod lens 6 attached to the first substrate 2 to bring the first adhesive 30 and the second adhesive 36 into contact with each other. A second bonding step is performed in which the rod lens array original plate 1 is formed by sandwiching a plurality of rod lenses 6 arranged in parallel on the surface of one substrate 2 between the first and second substrates 2 and 4. At this time, the adhesive 36 applied to the surface of the second substrate 4 in a strip shape is attached to the first substrate 2 in a parallel arrangement state. Then, the direction in which the second adhesive extends is arranged so as to be orthogonal to the direction in which the rod lens 6 extends, and is pressed against the rod lens 6 attached to the first substrate 2.

  At this time, since the cross-sectional shape of the second adhesive is convex, when the rod lens 6 attached to the first substrate 2 and the second substrate 4 are brought into contact with each other, the rod lens 6 and the second adhesive are bonded. It is possible to prevent air from being caught between the agents. Thereby, it can suppress that an air pocket arises in the rod lens array after manufacture. Then, the first substrate 2 and the second substrate 4 are further pressed relative to each other so that the adhesives 30 and 36 are brought into contact with each other, whereby the first and second substrates 2 and 4 and each rod lens 6 are bonded. The space between is filled with the adhesives 30 and 36 applied to the substrates 2 and 4 to form the adhesive layer 8. In addition, it is preferable that the adhesive layer 8 in the rod lens array original plate 1 maintains a pitch on which the first adhesive and the second adhesive are applied, and a gap remains between the belt-like adhesive layers 8. The adhesives 30 and 36 are preferably bonded so that their centers coincide.

  Thereafter, the rod lens array original plate 1 is preferably an environment having a temperature of 10 ° C. to 40 ° C. and a humidity of 20% RH to 85% RH, more preferably an environment having a room temperature of 15 ° C. to 25 ° C. and a humidity of 30% RH to 60% RH. It is preferable that the adhesives 30 and 36 are sufficiently cured by being left for 20 to 60 hours. It is difficult to cure the original plate as it is, and it is preferable that the original plate is completely cured after cutting because there are some cases where the original plate is swollen due to the generation of carbon dioxide gas.

  Furthermore, the cutting process which cut | disconnects the rod lens array original plate 1 along the 2nd adhesive agent 36 in the position where the 2nd adhesive agent 36 was apply | coated, and divides the 2nd adhesive agent 36 is performed. In this embodiment, as shown by a dotted line in FIG. 1, the rod lens array original plate 1 is moved along the direction in which the adhesives 30, 36 extend on the adhesives 30, 36 applied in strips to the original plates 2, 4. That is, the rod lens 6 is cut in a direction orthogonal to the extending direction of the rod lens 6 to form a rod lens array.

  The obtained rod lens array is preferably allowed to stand for 10 to 100 hours in an environment of a temperature of 50 ° C. to 80 ° C. and a humidity of 80% RH to 95% RH to sufficiently cure the adhesives 30 and 36. good. Thereafter, it is preferably cured at room temperature for 1 to 12 hours and completely cured under dry heat of 40 to 80 ° C.

  As described above, by applying the adhesives 30 and 36 to the substrates 2 and 4, it is possible to suppress a decrease in yield due to a small air pocket generated in the cut section or excessive filling of the adhesive. . In addition, since a sufficient gap can be secured between the adhesives after curing, when using a moisture-curing adhesive, the carbon dioxide generated from the adhesive is easily released during curing, allowing moisture to enter and curing sufficiently. And air retention can be suppressed.

  According to this embodiment, by applying the adhesive in a plurality of strips, when the rod lens is pressurized and embedded in the adhesive, or the substrate on which the adhesive is applied is pressed onto the rod lenses arranged on the substrate. The occurrence of air pockets can be suppressed when pasting together. As a result, the rod lens array can be efficiently and stably manufactured at low cost without adding a temporary bonding process or a filling process.

  The present invention is not limited to the above-described embodiment, and various changes and modifications can be made within the scope of the technical idea described in the claims.

For example, in the above embodiment, a moisture curable adhesive is used as the adhesive. However, in the present invention, the properties of the adhesive are not limited to the moisture curable adhesive, and other adhesives may be used.
Moreover, in the said embodiment, although the plane board | substrate was used as a board | substrate, this invention is applicable also to a board | substrate with a groove | channel.
The rod lens array obtained by cutting the rod lens array original plate 1 is cut and / or polished at both end surfaces perpendicular to the optical axis, thereby producing a rod lens array having a desired lens length and a mirror end surface. .

Hereinafter, the present invention will be described specifically by way of examples.
Example 1
An ABS plate was used as the substrate material, and a moisture curable adhesive (Esdyne (trade name) manufactured by Sekisui Chemical Co., Ltd.) was used as the adhesive material. Adhesive is charged into the adhesive charging pot 12 of the adhesive application device 10, air is sealed in the pot, and the pressure is maintained at about 100 ° C. and 0.3 MPa, and the adhesive is discharged to the adhesive charging pot 12. It has a structure in which five shim shapes are applied per application at a discharge pressure of 0.3 MPa from the nozzle 16 and has a width of 4 mm, a gap between adhesives of 1.5 mm, a length of 242 mm, and a thickness (Z11) of 48 to 51 μm. The first adhesive was applied directly to the surface of the first substrate 2 on which 30 rod lenses were fixed a total of 6 times at a pitch of 5.5 mm. The first adhesive application speed to the substrate of the coating apparatus was 100 mm / sec.

Next, a large number of rod lenses 6 were arranged in parallel while being sucked onto an array plate (grooved flat plate) and temporarily fixed. The rod lens material has a refractive index distribution in which the refractive index continuously decreases from the center of the circular cross section toward the outer periphery, and has a diameter of 0.35 mm, a length of 166 mm, a central refractive index of 1.497, a refractive index distribution constant. A 0.865 mm ⁻¹ plastic rod lens was used.

  The 1st board | substrate 2 which apply | coated the 1st adhesive agent was arrange | positioned under the rod lens 6 arranged in parallel with many in the grooved flat plate, the press was performed, and the rod lens 6 was moved to the 1st board | substrate 2. The pressing was performed by pressing the first substrate 2 against the rod lens 6, holding the temperature at 75 ° C. for 1 minute, and then holding at 20 ° C. for 1 minute. The press surface is made of an elastic material in order to prevent breakage of the grooved flat plate for arranging a large number of rod lenses and to uniformly press the entire surface.

After the press, a large number of rod lenses arranged in parallel fixed to the substrate were cured and cured for 12 hours.

Next, the second adhesive is discharged onto the surface of the other second substrate 4 from the adhesive discharge nozzle 16 provided with shims capable of being applied to the adhesive charging pot 12 and capable of applying five strips at a time. It was discharged at a pressure of 0.25 MPa, and the width was 1.2 mm, the pitch was 5.5 mm (gap between the second adhesive 4.5 mm), the length was 242 mm, and the thickness was 185 to 195 μm. Directly applied. The second adhesive application speed to the substrate of the coating apparatus was 100 mm / sec.
The cross-sectional shape of the adhesive applied at this time was observed with a three-dimensional microscope, and as a result, the convex shape shown in FIG. 11 was formed such that the width continuously decreased as the distance from the second substrate 4 increased.

The first substrate 2 to which a large number of rod lenses 6 fixed by curing and curing are adhered is bonded to the second substrate 4 having the second adhesive applied in a strip shape on one surface as described above, and is first bonded. The agent and the second adhesive were brought into contact with each other and pressed under the same conditions to produce the rod lens array original plate 1 and further cured for 24 hours.
Next, the rod lens array original plate 1 is cut along both adhesives at a position where the first and second adhesives are applied at a pitch of 5.5 mm in a direction orthogonal to the rod lenses 6, and the rod lenses are cut. Both end surfaces of the array were mirror-polished perpendicularly to the optical axis to produce a plurality of rod lens arrays having a lens length of 4.4 mm.

  Using a microscope, air pockets existing in the adhesive layer on the surface of the cross section of the produced rod lens array were examined. Table 1 shows the ratio of the number of rod lenses in which air pockets exist. As shown in Table 1, no air retention was observed in the obtained rod lens array.

(Examples 2-3)
As shown in Table 1, a rod lens array was manufactured in the same manner as in Example 1 except that the adhesive application width was changed, and air pockets present in the adhesive layer were examined. The results are shown in Table 1.
(Table 1)

(Comparative Examples 1-3)
A rod lens array was produced in the same manner as in Example 1 except that the adhesive was applied as shown in Table 1.

  Further, the presence or absence of air pockets in the adhesive layer was examined by microscopic observation on the surface of the prepared rod lens array cross section. The results are shown in Table 1. Moreover, about the 2nd adhesive agent apply | coated on the conditions of the comparative example 3, the cross-sectional shape obtained by three-dimensional microscope observation is shown in FIG.

  As described above, in the comparative example in which the cross-sectional shape of the adhesive is not continuously reduced in width, the number of arrays in which air pockets exist was about 30% of the total. In Comparative Example 1 in which the adhesive application width was narrowed to 0.5 mm, the adhesive was insufficiently filled.

2: First substrate 4: Second substrate 6: Rod lens 8: Adhesive layer 30: First adhesive 34: Arrangement plate 36: Second adhesive

Claims (3)

A method of manufacturing an optical transmitter array in which a plurality of cylindrical optical transmitters are arranged in parallel between a first substrate and a second substrate,
A first application step of applying a first adhesive to the surface of the first substrate;
A plurality of the optical transmission bodies are arranged in parallel, the optical transmission bodies arranged in parallel are brought into contact with the first adhesive applied to the first substrate, and the optical transmission bodies are attached to the first substrate. A first bonding step;
A second application step of applying a plurality of parallel strips of the second adhesive on the surface of the second substrate;
The direction in which the strip-shaped second adhesive extends between the second adhesive applied to the second substrate and the optical transmission body attached to the first substrate is a columnar shape of the optical transmission body. Direct to the center axis
Contact to intersect , attach the first substrate, the optical transmission body, and the second substrate,
A second bonding step for obtaining an optical transmitter array original plate;
Cutting the optical transmitter array original plate to obtain an optical transmitter array, and
Each of the bands of the second adhesive applied in the second application step has a cross-sectional shape in a direction orthogonal to the direction in which the bands extend, and the width continuously decreases in a direction away from the second substrate. One convex shape to
The maximum value of the width is 0.8 mm or more and 2.0 mm or less, and the height of the cross section is 100 μm.
More than 250 μm,
Manufacturing method of optical transmitter array. The pitch of the first application process and the second application process is the same, as claimed in claim 1.
Manufacturing method of optical transmitter array. 3. The optical transmission according to claim 1 , wherein, in the cutting step, the optical transmission element array original plate is obtained by cutting the optical transmission element array original plate in parallel with a direction in which the row extends at the application position of the second adhesive. Body array manufacturing method.