JP5874965B2 - Micro lens array bonding device - Google Patents

Description

  The present invention relates to a microlens array bonding apparatus in a microlens array manufacturing apparatus in which a plurality of unit microlens arrays in which microlenses are two-dimensionally arranged are stacked and bonded to each other. The present invention also relates to a bonding apparatus for a microlens array capable of adjusting magnification and focus with high accuracy.

  A microlens array is formed by two-dimensionally forming a plurality of convex microlenses on one or both sides of a single glass substrate, and the resulting unit microlens arrays are stacked on top of each other, with a predetermined interval between them. It is manufactured by adhering to each other. A microlens array is usually composed of four unit microlens arrays, and a hexagonal field stop, for example hexagonal, is placed between the second and third sheets, and inverted at the position of this hexagonal field stop. Lens designs such as the spacing between the unit microlens arrays are made so that an equal magnification image is obtained and an erecting equal magnification image is finally obtained by the four unit microlens arrays. As a method for manufacturing a microlens array, there is Patent Document 1.

JP 2000-304904 A

  However, in a conventional microlens array manufacturing apparatus, unit microlens arrays are joined together as they are after the unit microlens arrays are manufactured with predetermined design values. For this reason, each unit microlens array cannot be positioned with high precision, the space | interval between unit microlens arrays cannot be adjusted with high precision, and the magnification and focus cannot be adjusted. Therefore, the conventional microlens array has a problem that the performance of the combined lens cannot be sufficiently improved. Also in Patent Document 1, planar alignment between unit microlens arrays is performed, but the unit microlens arrays are joined so that there is no gap between them, and therefore magnification adjustment and the like cannot be performed.

  The present invention has been made in view of such problems, and at the time of manufacturing a microlens array, the interval between unit microlens arrays can be adjusted with high accuracy, and magnification and focus adjustment can be performed. An object of the present invention is to provide a bonding apparatus for a microlens array that can produce an excellent microlens array.

A microlens array bonding apparatus according to the present invention is a microlens array bonding apparatus in which a plurality of unit microlens arrays each having a microlens formed on a glass substrate are stacked at a predetermined interval and bonded to each other with an adhesive. In
A plurality of first holding members for individually holding a plurality of the unit microlens arrays;
A reference mask disposed on one side of the assembly of unit microlens arrays and provided with a reference mask pattern;
A focusing screen disposed on the other side of the assembly of the unit microlens arrays and having a focusing screen pattern formed thereon;
A second holding member for holding the reference mask;
A third holding member for holding the focusing screen;
A drive device for adjusting the position of the first to third holding members;
A measuring member for measuring a distance between a first surface of the reference mask on which the reference mask pattern is formed and a second surface of the focusing screen on which the focusing screen pattern is formed;
A detector that detects the first image of the reference mask pattern and the second image of the focusing screen pattern in the same field of view;
The positions of the second holding member and the third holding member are adjusted so that the distance between the first surface and the second surface measured by the measuring member is a predetermined design value, and further, the detecting unit A controller that adjusts the position of the unit microlens array by adjusting the position of the first holding member so that the detected first image and second image are in focus;
It is characterized by having.

In this microlens array bonding apparatus, for example,
An alignment mark is formed on the unit microlens array, and a light source that irradiates the aggregate of the unit microlens array with transmitted illumination light that passes through the alignment mark;
A second detector for detecting transmitted illumination light transmitted through the alignment mark;
Have
The control unit further adjusts the position of each unit microlens array by the first holding member so that the position of the alignment mark of each unit microlens array detected by the second detection unit is aligned. Can be configured.

Moreover, the bonding apparatus for the microlens array of the present invention includes:
A dispenser that is disposed in a peripheral portion of the unit microlens array and injects an adhesive into a peripheral portion of the unit microlens array;
An ultraviolet light source that is disposed in a peripheral portion of the unit microlens array and irradiates the adhesive injected into the peripheral portion of the unit microlens array with ultraviolet light to solidify the adhesive;
It can comprise so that it may have.

  According to the present invention, the first surface and the second surface are detected by using a reference mask pattern and a focusing screen pattern provided on the first surface of the reference mask and the second surface of the focusing screen by a detection unit such as a CCD camera. It is confirmed that the surface is at the in-focus position, the distance between the first surface and the second surface is measured by the measuring member, and the distance between the first surface and the second surface is a predetermined design value. If not, the distance between the reference mask and the focusing screen is adjusted to a predetermined design value. At this time, when there is no focal position on the first surface and the second surface, the distance between the unit microlens arrays is adjusted so that the focal position exists on the first surface and the second surface. Adjust to. In this way, it is possible to adjust the magnification and the focus by adjusting the interval between the unit microlens arrays with high accuracy. Therefore, according to the present invention, a microlens array having excellent lens performance can be manufactured.

  Further, by providing an alignment mark on the unit microlens array, the second detection unit can detect the alignment mark and align the planar position of each unit microlens array.

It is a front view which shows the bonding apparatus of the micro lens array of 1st Embodiment of this invention. It is the figure which similarly extracts the part and shows the arrangement | positioning aspect of a unit micro lens array. It is a figure which shows the process of measuring the gap between each unit micro lens array. (A), (b) is a figure which shows the process of adjusting the focus position by each unit micro lens array. (A) is a figure which shows the injection | pouring process of an adhesive agent, and (b) is a figure which shows the solidification process of an adhesive agent.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. FIG. 1 is a front view showing a microlens array bonding apparatus according to an embodiment of the present invention. In the present embodiment, a group of three unit microlens arrays 1, 2, and 3 are bonded together to manufacture a microlens array composed of three unit microlens array groups. The same applies when the lens arrays are bonded together. Unit microlens arrays 1, 2, and 3 are held by holding means such as an electrostatic chuck or a vacuum chuck on holding members 11, 12, and 13 as first holding members. The unit microlens arrays 1, 2, and 3 are formed by forming convex lenses (microlenses) on the front surface and / or back surface of the glass substrate. Laminated layers are arranged so that the optical axes coincide with each other, and are joined by an adhesive.

  In a three-dimensional coordinate axis in which the XY orthogonal coordinate is the horizontal direction and the Z direction is the vertical direction, the holding member 11 as the first holding member is the vertical direction (Z direction), the tilt direction (Tx) with respect to the X axis, and the Y axis Can be moved in a tilting direction (Ty) with respect to, and is driven by appropriate driving means (an actuator such as a piezoelectric element). Further, the holding member 12 is movable in the X direction and the Y direction, and the rotational direction (θ axis) around the vertical axis, and is driven by appropriate driving means. Further, the holding member 13 is movable in the X direction, the Y direction, the θ direction, the Z direction, the Tx direction, and the Ty direction, and is driven by appropriate driving means.

  Then, below these unit microlens array groups, the reference mask 4 is disposed while being held by a holding member 14 as a second holding member. Further, the focusing screen 5 is disposed above the unit microlens array group and held by a holding member 15 as a third holding member. The holding member 14 can move in the Z direction, the Tx direction, and the Ty direction, and is driven by appropriate driving means. Further, the holding member 15 is also movable in the Z direction, the Tx direction, and the Ty direction, and is driven by appropriate driving means.

  On the other hand, laser displacement meters 31 and 32 as measurement members are arranged below the reference mask 4 with their measurement directions facing directly above, and the laser displacement meters 31 and 32 are respectively arranged on the upper surface of the reference mask 4. And the distance between the lower surface of the focusing screen 5 is measured. A reference mask pattern P 1 is formed on the upper surface of the reference mask 4, and a focusing screen pattern P 2 is formed on the lower surface of the focusing screen 5. The reference mask pattern P1 and the focusing screen pattern P2 are observed within the same visual field by the CCD camera 21 disposed above the focusing screen 5. However, the reference mask pattern P1 and the focusing screen mask pattern P2 are observed at positions where they do not overlap. FIG. 4B shows an image of the focusing screen pattern P2 detected by the camera 21 and an image of the reference mask pattern P1. Although the detection sensor of the camera 21 is a CCD, the camera 21 is an epi-illumination camera, which irradiates illumination light on the same optical axis and receives reflected light. The camera 21 is installed with its focal position aligned with the lower surface of the focusing screen 5. Therefore, the focusing screen pattern P2 on the lower surface of the focusing screen 5 must be filled with ■ as shown in FIG. Detect at the focal point. On the other hand, the reference mask pattern P1 on the reference mask 4 is obtained when the illumination light from the camera 21 is focused on the upper surface of the reference mask 4 through the microlens array including the unit microlens arrays 1, 2, and 3. A square-shaped image is observed. On the other hand, when the magnification of the microlens array including the unit microlens arrays 1, 2, and 3 is abnormal, the square-shaped image is observed larger than the normal image. Further, when the focus of the microlens array is abnormal, the image of the reference mask pattern P1 is observed in a non-focused state where the focus is not achieved. In the case of magnification abnormality and focus abnormality, the control device (not shown) adjusts the mutual interval between the unit microlens arrays 1, 2, and 3 so that a normal focused image can be obtained.

  Each unit microlens array 1, 2, 3 is provided with alignment marks P3, P4 (only two are shown) at the four corners thereof. Below the reference mask 4 are transmitted illumination light sources 24, 25 for detecting the alignment marks P3, P4. The illumination light from the transmitted illumination light sources 24, 25 is the reference mask 4, unit. The light passes through the microlens array 1.2.3 and the focusing screen 5, and is detected by the alignment cameras 22 and 23 disposed above the focusing screen 5. The cameras 22 and 23 detect the alignment marks P3 and P4 provided on the unit microlens arrays 1, 2 and 3 so that a control device (not shown) aligns the unit microlens arrays 1, 2 and 3. Next, the planar positions of the unit microlens arrays 1, 2, and 3 are adjusted.

  Contact type displacement meters 33 and 34 for detecting the vertical position of the uppermost unit microlens array 3 are installed on the periphery of the focusing screen 5. The contact displacement meters 33 and 34 contact the upper surface of the unit microlens array 3 to detect the position thereof, and the control device obtains an interval between the unit microlens arrays based on the detection result. In place of the contact displacement meters 33 and 34, a capacitance-type non-contact displacement meter can be used.

  Dispensers 41 and 42 for injecting adhesive are disposed between the unit microlens array 3 and the unit microlens array 2 below the unit microlens array 3 at the periphery of the uppermost unit microlens array 3. From the dispensers 41 and 42, a fluid adhesive is injected between the peripheral portion of the unit microlens array 3 and the peripheral portion of the unit microlens array 2. In addition, it is preferable that beads having a diameter corresponding to a predetermined interval between the unit microlens array 3 and the unit microlens array are mixed in the adhesive. In other words, if the predetermined interval between the unit micro lens arrays is 10 μm, a large number of resin-made beads having a diameter close to 10 μm are mixed in the adhesive, and the adhesive containing these beads is interposed between the unit micro lens arrays. By doing so, the beads contact the surfaces of both unit microlens arrays, and the bead can determine the gap between the unit microlens arrays. Then, as shown in FIG. 5A, after the injection of the adhesive by the dispensers 41 and 42 is finished, the adhesive 51 is irradiated with ultraviolet light by the ultraviolet light sources 43 and 44 as shown in FIG. 5B. Then, the adhesive 51 is solidified.

  Next, the operation of the microlens array bonding apparatus configured as described above will be described. First, as shown in FIG. 2, the unit microlens arrays 1, 2, and 3 are held by the holding members 11, 12, and 13 at their edges by means of an electrostatic chuck or a vacuum chuck, respectively. Then, as shown in FIG. 3, the holding members 11, 12, and 13 are moved to the bonding apparatus of this embodiment, and the unit microlens arrays 1, 2, and 3 are installed in the bonding apparatus. However, in this bonding step, first, before the unit microlens arrays 2 and 3 are arranged on the unit microlens array 1, the position of the upper surface of the unit microlens array 1 is determined by the contact displacement meters 33 and 34. To detect. Next, the unit microlens array 2 is disposed above the unit microlens array 1, and the position of the upper surface of the unit microlens array 2 is detected by the contact displacement meters 33 and 34. Thereafter, the unit microlens array 3 is disposed above the unit microlens array 2, and the position of the upper surface of the unit microlens array 3 is detected by the contact displacement meters 33 and 34. As a result, the gap g between the unit microlens arrays 1, 2, 3 can be measured. That is, as shown in FIG. 3, by measuring the position of the upper surface of the unit microlens array 3 and the position of the upper surface of the unit microlens array 2, the difference d can be obtained. Since the thickness t of the unit microlens array 3 is separately grasped in the manufacturing process of the unit microlens array 3, the distance between the unit microlens array 3 and the unit microlens array 2 is obtained by dt. (Gap) g can be obtained. Similarly, the gap g between the unit microlens array 1 and the unit microlens array 2 can also be measured. Then, the controller drives the holding members 11, 12, and 13 so that the gap g becomes a predetermined design value, and determines the positions of the unit microlens arrays 1, 2, and 3 for the time being. In this case, the holding member 12 of the unit microlens array 2 can move in the X direction, Y direction, and θ direction, but cannot move in the Z direction. The holding member 11 that holds the lens array 1 is moved in the Z direction, or the inclination angles in the Tx direction and the Ty direction are adjusted, and the holding member 13 that holds the unit microlens array 3 is moved in the Z direction, or By adjusting the tilt angles in the Tx direction and the Ty direction, the mutual arrangement relationship (parallel and spacing) between the unit microlens arrays 1, 2, and 3 is set temporarily.

  Thereafter, as shown in FIG. 4, transmitted illumination light is irradiated from the transmitted illumination light sources 24, 25 toward the alignment marks P 3, P 4, and the transmitted light is detected by the alignment cameras 22, 23. The control unit drives the holding members 11, 12, 13 so that the alignment marks P 3, P 4 detected by the cameras 22, 23 coincide with each other for the unit micro lens arrays 1, 2, 3, and thereby each unit micro lens. The alignment of the arrays 1, 2, and 3 in plan view is performed.

  Next, the laser displacement meters 31 and 32 measure the distance between the upper surface of the reference mask 4 and the lower surface of the focusing screen 5. When the distance between the upper surface of the reference mask 4 and the lower surface of the focusing screen 5 is different from the design value of the predetermined microlens array, the control unit drives the holding member 14 and the upper surface of the reference mask 4. And the distance between the focusing screen 5 and the lower surface of the focusing screen 5 is controlled so as to coincide with a predetermined design value. The position of the holding member 15 is basically not changed because the position of the lower surface of the focusing screen 5 held by the holding member 15 is set to be the focal position of the camera 21. Then, the incident-light CCD camera 21 detects an image of the reference mask pattern P1 on the upper surface of the reference mask 4 and an image of the focusing screen pattern P2 on the lower surface of the focusing screen 5. As a result, as shown in FIG. 4B, since the focal position of the camera 21 is on the lower surface of the focusing screen 5, the image of the focusing screen pattern P2 has a rectangular square shape and is in focus, but the reference mask When the image of the fourth reference mask pattern P1 is large and a magnification abnormality occurs, or when the image of the reference mask pattern P1 is out of focus and a focus abnormality occurs, the control unit performs the holding members 11, 12, 13 is driven to adjust the interval between the unit microlens arrays 1, 2, and 3. That is, the control unit adjusts the interval between the unit microlens arrays 1, 2, and 3 to obtain an image of the reference mask pattern P1 shown as normal in FIG. As a result, when the light focused on the lower surface of the focusing screen 5 is transmitted through the microlens array including the unit microlens arrays 1, 2, 3, this light passes through the unit microlens arrays 1, 2, 3. Thus, the upper surface of the reference mask 4 is focused.

  That is, in this state, the unit microlens arrays 1, 2, and 3 are aligned in plane, and the focal position coincides with the lower surface of the focusing screen 5 and the upper surface of the reference mask 4. The interval is equal to a predetermined design value. Therefore, a fluid adhesive is injected from the dispensers 41 and 42 between the edge portions of the unit microlens arrays 1, 2, and 3 (in FIG. 1, between the unit microlens array 2 and the unit microlens array 3. Only). When resin beads having a diameter close to a predetermined interval between the unit microlens arrays are mixed between the adhesives, the beads come into contact with the mutually facing surfaces of the unit microlens arrays 1, 2, and 3. The interval between the unit microlens arrays 1, 2, 3 can be determined. However, as described above, the intervals between the unit microlens arrays 1, 2, and 3 are slightly modified by the holding members 11, 12, and 13 so that the focal point is on the upper surface of the reference mask 4 and the lower surface of the focusing screen 5. Therefore, the resin beads are slightly pressed and deformed as necessary. After the adhesive is injected between the unit microlens array 1 and the unit microlens array 2, the adhesive is irradiated with ultraviolet light from the ultraviolet light sources 43 and 44 to solidify the adhesive. . Further, as shown in FIGS. 5A and 5B, an adhesive is injected between the unit microlens array 2 and the unit microlens array 3, and the adhesive 51 is irradiated with ultraviolet light. 51 is solidified. The beads are not limited to resin beads but may be made of glass.

  In this way, the lower surface of the focusing screen 5 and the upper surface of the reference mask 4 are focused, the distance between the focal points matches a predetermined design value, and the alignment between the unit microlens arrays 1, 2, 3 is performed. A microlens array made with high accuracy can be manufactured. In the present embodiment, when the unit microlens arrays 1, 2, and 3 are bonded together, the performance of the microlens array (focal position, interfocal distance, magnification, etc.) is tested, and if necessary, the unit microlens array Since the predetermined lens performance is obtained by adjusting the distance between the lens arrays 1, 2, and 3, a high-performance microlens array can be manufactured.

  The present invention is useful in the manufacture of high performance microlens arrays.

1.2.3: Unit microlens arrays 11, 12, 13, 14, 15: Holding member 21: (Ejecting CCD) camera 22, 23: (Alignment) camera 24, 25: Transmitted illumination light source 31, 32: Laser Displacement meter 33, 34: Contact displacement meter 41, 42: Dispenser 43, 44: Ultraviolet light source 51: Adhesive P1: Reference mask pattern P2: Focus plate pattern P3, P4: Alignment mark

Claims (3)

In a bonding apparatus for a microlens array in which a plurality of unit microlens arrays in which microlenses are formed on a glass substrate are stacked at a predetermined interval and bonded to each other with an adhesive,
A plurality of first holding members for individually holding a plurality of the unit microlens arrays;
A reference mask disposed on one side of the assembly of unit microlens arrays and provided with a reference mask pattern;
A focusing screen disposed on the other side of the assembly of the unit microlens arrays and having a focusing screen pattern formed thereon;
A second holding member for holding the reference mask;
A third holding member for holding the focusing screen;
A drive device for adjusting the position of the first to third holding members;
A measuring member for measuring a distance between a first surface of the reference mask on which the reference mask pattern is formed and a second surface of the focusing screen on which the focusing screen pattern is formed;
A detector that detects the first image of the reference mask pattern and the second image of the focusing screen pattern in the same field of view;
The positions of the second holding member and the third holding member are adjusted so that the distance between the first surface and the second surface measured by the measuring member is a predetermined design value, and further, the detecting unit A controller that adjusts the position of the unit microlens array by adjusting the position of the first holding member so that the detected first image and second image are in focus;
A bonding apparatus for a microlens array, comprising: An alignment mark is formed on the unit microlens array, and a light source that irradiates the aggregate of the unit microlens array with transmitted illumination light that passes through the alignment mark;
A second detector for detecting transmitted illumination light transmitted through the alignment mark;
Have
The control unit further adjusts the position of each unit microlens array by the first holding member so that the position of the alignment mark of each unit microlens array detected by the second detection unit is aligned. The microlens array bonding apparatus according to claim 1, wherein the bonding apparatus is a microlens array bonding apparatus. A dispenser that is disposed in a peripheral portion of the unit microlens array and injects an adhesive into a peripheral portion of the unit microlens array;
An ultraviolet light source that is disposed in a peripheral portion of the unit microlens array and irradiates the adhesive injected into the peripheral portion of the unit microlens array with ultraviolet light to solidify the adhesive;
The microlens array laminating device according to claim 1, wherein the microlens array laminating device is provided.

Images