JP2007079221A - Direct drawing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a direct drawing device that can increase much more the dot density in a pattern to be drawn. <P>SOLUTION: A stage holds an exposure object having a photosensitive film formed on the surface. An XY orthogonal coordinate system is defined having an XY plane parallel to the surface of the exposure object held on the stage. The stage moves the exposure object held by the stage in the X axis direction. An exposure light source includes a first light-emitting pixel array parallel to the XY plane and including a plurality of light-emitting pixels arranged along an oblique first direction with respect to the Y axis direction. A light beam emitting from each light-emitting pixel exposes the photosensitive film on the exposure object held by the stage. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a direct drawing apparatus, and more particularly to a direct drawing apparatus that can directly draw a circuit pattern on a photoresist film formed on a printed circuit board.

  Known methods for drawing a circuit pattern on a photoresist film on a printed circuit board include contact exposure, reduced projection exposure, and proximity exposure using a photomask on which a circuit pattern is formed. As the number of printed circuit boards is increased, the photomasks must be manufactured for each type of printed circuit board. For this reason, a direct drawing method that does not use a photomask attracts attention.

  A photoresist pattern direct drawing apparatus disclosed in Patent Document 1 below will be described. An exposure light source having edge-emitting electroluminescence (EL) elements arranged in an array is arranged above the substrate. The light emission of each EL element is on / off controlled by the control circuit. Light emitted from each EL element is irradiated onto the substrate by the condensing optical system.

  A desired pattern can be drawn by controlling on / off of light emission of each EL element while moving one of the exposure light source and the substrate in a direction orthogonal to the direction in which the EL elements are arranged.

  Patent Document 2 below discloses a print head for an electrophotographic printer using a light emitting diode (LED) array chip. The light emitting parts are arranged in a staggered manner in two rows. By arranging in two rows in a staggered manner, the print dot density can be increased.

Japanese Patent Laid-Open No. 5-80524 JP 2000-289250 A

  An object of the present invention is to provide a direct drawing apparatus capable of further increasing the dot density of a pattern to be drawn.

  According to one aspect of the present invention, when an XY orthogonal coordinate system is defined in which a photosensitive film holds an exposure object formed on the surface and a plane parallel to the surface of the held exposure object is an XY plane, A stage for moving the held exposure object in the X-axis direction, and a plurality of light-emitting pixels arranged in a first direction parallel to the XY plane and oblique to the Y-axis direction. There is provided a direct drawing apparatus having an exposure light source including a first light emitting pixel array for exposing a photosensitive film on an exposure object held by the stage to which emitted light is exposed.

  Since the first direction in which the light emitting pixels are arranged is inclined with respect to the Y axis, the dot density in the Y axis direction of the image to be drawn can be increased.

  FIG. 1A shows a front view of a direct drawing apparatus according to the first embodiment. An X stage 2 is mounted on the base 1. On the X stage 2, a printed circuit board 10 that is an object to be exposed is held. A photosensitive film made of a dry film resist (DF resist) or a solder resist that is exposed to ultraviolet light is provided on the surface of the printed circuit board 10. An XYZ orthogonal coordinate system is defined in which a plane parallel to the surface of the printed circuit board 10 held on the X stage 2 is an XY plane. The X stage 2 moves the printed circuit board 10 in the X-axis direction by receiving control from the control device 4. An exposure light source 3 is disposed above the printed circuit board 10 held on the X stage 2.

  FIG. 1B shows a plan view of the direct drawing apparatus shown in FIG. The exposure light source 3 includes a large number of light emitting pixels 30A. Each of the light emitting pixels 30A is configured by an LED that emits ultraviolet light in a wavelength range of 350 nm to 410 nm. The light emitting pixels 30A are arranged along a center line 31A that is parallel to the XY plane and oblique to the Y-axis direction.

  FIG. 2 shows a schematic perspective view of the exposure light source 3. A plurality of LED arrays 33 and driver circuits 34 are mounted on the mounting substrate 32. The LED array 33 is arranged along the center line 31A. Each LED array 33 is formed with a plurality of light emitting pixels 30A arranged along the center line 31A. In this manner, the plurality of LED arrays 33 constitute one long light emitting pixel array 3A.

  The SELFOC lens array 35 is disposed at a position where light emitted from the light emitting pixel 30A is incident. The Selfoc lens array 35 is configured by arranging a number of Selfoc lenses having an axis perpendicular to the XY plane in a two-dimensional direction parallel to the XY plane. The Selfoc lens array 35 forms an erecting equal-magnification image of the light emitting pixels 30A on the surface 10S of the printed circuit board 10 held on the X stage 2 shown in FIGS. 1 (A) and 1 (B). That is, an image having the same pattern as the arrangement pattern of the light emitting pixels 30 </ b> A is formed on the surface of the printed board 10.

  The control device 4 shown in FIG. 1A performs position control of the X stage 2 and light emission timing control of each light emitting pixel 30 </ b> A of the exposure light source 3.

  FIG. 3A shows a schematic plan view of the light emitting pixel array 3A constituting the exposure light source 3. FIG. The light emitting pixels 30A are arranged at a pitch P (distance between the centers of the light emitting pixels adjacent to each other) along the center line 31A. The pitch P of the light emitting pixels 30A is, for example, 42.4 μm.

  An angle formed by the center line 31A and the Y axis is defined as θ. A distance Py in the Y-axis direction between the centers of the light emitting pixels 30A adjacent to each other is Pcos θ, which is narrower than the original pitch P. Hereinafter, unless otherwise specified, “the interval between the light emitting pixels” means the distance between the centers of the light emitting pixels. For example, when the angle θ is 45 °, the interval Py in the Y-axis direction is about 30 μm.

  While controlling the X stage 2 and moving the printed circuit board 10 in the X-axis direction, the timing of the emission of the light emitting pixels 30A is controlled based on the image data to be drawn, thereby providing a photosensitive provided on the surface of the printed circuit board 10. Drawing directly on the film. Since the positions of the plurality of light emitting pixels 30A are shifted in the X-axis direction, a desired image can be formed by shifting the light emission timing of the light emitting pixels 30A by the time corresponding to the magnitude of the shift.

  The pitch of dots in the Y-axis direction of the drawn image is equal to the interval Py in the Y-axis direction of the light emitting pixels 30A. For this reason, the dot density in the Y-axis direction can be increased as compared with the case where the center line 31A is arranged in parallel to the Y-axis.

  FIG. 3B shows a schematic plan view of the exposure light source 3 of the direct drawing apparatus according to the second embodiment. The exposure light source 3 of the second embodiment includes a second light emitting pixel array 3B in addition to the light emitting pixel array 3A constituting the exposure light source 3 according to the first embodiment. The second light emitting pixel array 3B has the same structure as the first light emitting pixel array 3A. Similarly to the first light emitting pixel array 3A shown in FIG. 2, a driver circuit and a selfoc lens array are also attached to the second light emitting pixel array 3B.

  The center line 31B of the second light emitting pixel array is parallel to the center line 31A of the first light emitting pixel array 3A, and both are inclined with respect to the Y axis. With respect to the Y-axis direction, the second light emitting pixel array 3B is arranged such that the position of one light emitting pixel 30B is the center of the positions of two light emitting pixels 30A adjacent to each other in the first light emitting pixel array 3A. The light emitting pixel array 3B is displaced in the Y-axis direction with respect to the first light emitting pixel array 3A. With respect to the X-axis direction, they are arranged so as not to overlap each other.

  When the angle formed between the center lines 31A and 31B of the first light emitting pixel array 3A and the second light emitting pixel array 3B and the Y axis is equal to the angle θ of the first embodiment, in the second embodiment, Y The interval between the light emitting pixels in the axial direction is ½ of the interval in the first embodiment. For this reason, it is possible to double the dot density in the Y-axis direction.

  FIG. 4A shows a schematic plan view of a light emitting pixel array 3C constituting an exposure light source of the direct drawing apparatus according to the third embodiment. Similarly to the first light emitting pixel array 3A shown in FIG. 2, a driver circuit and a selfoc lens array are also attached to the light emitting pixel array 3C. In the light-emitting pixel array 3C according to the third embodiment, the light-emitting pixels 30A are alternately arranged on the first side of the center line 31C and the opposite second side in a plane parallel to the XY plane. Yes. The light emitting pixels 30Ca arranged on the first side and the light emitting pixels 30Cb arranged on the second side are both arranged in parallel to the center line 31C at the same pitch P. With respect to the direction parallel to the center line 31C, the second side light emitting pixel 30Cb is arranged at a position shifted from the first side light emitting pixel 30Ca by 1/2 of the pitch P.

  The center line 31C is inclined by an angle θ with respect to the Y axis. Let W be the interval between a straight line connecting the centers of the light emitting pixels 30Ca arranged on the first side and a straight line connecting the centers of the light emitting pixels 30Cb arranged on the second side.

  Attention is paid to the first light-emitting pixel 30Ca1 and the second light-emitting pixel 30Ca2 that are adjacent to each other on the first side, and the third light-emitting pixel 30Cb1 on the second side disposed therebetween. The distance Py2 between the first light emitting pixel 30Ca1 and the third light emitting pixel 30Cb1 in the Y axis direction is different from the distance Py1 between the second light emitting pixel 30Ca2 and the third light emitting pixel 30Cb1 in the Y axis direction. Consider a case where the interval Py2 is wider than the interval Py1.

  The intervals Py1 and Py2 are given by the following equations.

Py1 = (P / 2) cos θ−W sin θ
Py2 = (P / 2) cos θ + Wsin θ
Consider a case where the interval Py2 is three times the interval Py1. If drawing is performed once while the printed circuit board 10 is moved in the X-axis direction, the dot spacing in the Y-axis direction becomes non-uniform. The printed circuit board 10 or the light emitting pixel array 3C is displaced by a distance twice as large as the interval Py1 in the Y-axis direction, and in this state, the second drawing is performed while moving the printed circuit board 10 in the X-axis direction. Since the drawing can be performed inside the wider interval Py2 in the second drawing, the dots for drawing can be uniformly distributed over the entire surface. Compared to the case where the central axis 31C of the light emitting pixel array 3C is arranged in parallel to the Y axis, the dots for drawing can be distributed with a higher density.

  More generally, the ratio between the interval Py1 and the interval Py2 may be 1: (2n + 1) (n is a natural number). In this case, by performing n times of drawing, the dots of the drawn image can be uniformly distributed. For example, when the pitch P and the interval W of the light emitting pixel array 3C are fixed in advance, the above condition can be satisfied by adjusting the angle θ.

  FIG. 4B is a schematic plan view of the exposure light source of the direct drawing apparatus according to the fourth embodiment. The exposure light source according to the fourth embodiment includes another second light emitting pixel array 3D in addition to the light emitting pixel array 3C of the third embodiment shown in FIG. Similarly to the first light emitting pixel array 3A shown in FIG. 2, a driver circuit and a selfoc lens array are also attached to the second light emitting pixel array 3D. The second light emitting pixel array 3D has the same structure as the first light emitting pixel array 3C. That is, the arrangement pattern of the light emitting pixels 30D of the second light emitting pixel array 3D is the same as the arrangement pattern of the light emitting pixels 30C of the first light emitting pixel array 3C. The central axis 31D of the second light emitting pixel array 3D is parallel to the central axis 31C of the first light emitting pixel array 3C.

  The light emitting pixel 30D of the second light emitting pixel array 3D is arranged at a position where the light emitting pixel 30C of the first light emitting pixel array 3C is translated in the Y axis direction by a distance twice as large as the interval Py1 in the Y axis direction. Has been. In the X-axis direction, an appropriate interval is secured so that the first and second light emitting pixel arrays 3C and 3D do not overlap.

  The light emitting pixels 30C of the first light emitting pixel array 3C and the light emitting pixels 30D of the second light emitting pixel array 3D are uniformly distributed with a pitch Py1 in the Y-axis direction as a whole. For this reason, by moving the printed board 10 once in the X-axis direction, the dots of the image to be drawn can be uniformly distributed over the entire surface.

  FIG. 5 shows a schematic plan view of a light emitting pixel array 3E constituting an exposure light source of the direct drawing apparatus according to the fifth embodiment. Similarly to the first light emitting pixel array 3A shown in FIG. 2, a driver circuit and a selfoc lens array are also attached to the light emitting pixel array 3E. In the light emitting pixel array 3E according to the fifth embodiment, the light emitting pixels 30E are arranged on both sides of the center line 31E. The arrangement pattern of the light emitting pixels 30E is line symmetric with respect to the center line 31E. The light emitting pixels 30E arranged on one side are arranged at a pitch P parallel to the center line 31E.

  The center line 31E is inclined by an angle θ with respect to the Y axis. At one side, attention is paid to the first light emitting pixel 30E1, the second light emitting pixel 30E2, and the third light emitting pixel 30E3 which are in line symmetry with the first light emitting pixel 30E1 with respect to the center line 31E. . With respect to the Y-axis direction, the center line 31E is inclined so that the third light emitting pixel 30E3 is located between the first light emitting pixel 30E1 and the second light emitting pixel 30E2.

The interval between the first light emitting pixel 30E1 and the third light emitting pixel 30E3 in the Y-axis direction is Py1, and the interval between the third light emitting pixel 30E3 and the second light emitting pixel 30E2 in the Y axis direction is Py2. Let W be the interval between the first light emitting pixel 30E1 and the third light emitting pixel 30E3. At this time,
Py1 = Wsinθ
Py2 = Pcosθ−Wsinθ
It is expressed. The intervals Py1 and Py2 are narrower than the pitch P. Also in the fifth embodiment, the dots of the drawn image can be arranged with higher density.

If the inclination angle θ is determined so that the interval Py1 and the interval Py2 are equal, the dot density in the Y-axis direction can be made uniform. The inclination angle θ is
θ = tan ⁻¹ (P / 2W)
When satisfying, the intervals Py1 and Py2 are equal.

  FIG. 6 shows a schematic plan view of an exposure light source of the direct drawing apparatus according to the sixth embodiment. The exposure light source 3 according to the sixth embodiment is composed of four light emitting pixel arrays 3F to 3I. For each of the light emitting pixel arrays 3F to 3I, a driver circuit and a Selfoc lens array are prepared in the same manner as the first light emitting pixel array 3A shown in FIG. Each of the light emitting pixel arrays 3F to 3I reduces the number of light emitting pixels of the light emitting pixel array 3A according to the first embodiment shown in FIG. 3A to ¼, and has a length of about 1 as the number of pixels decreases. It has the same structure as that of / 4. The central axis 31F of the first light emitting pixel array 3F is inclined by an angle θ with respect to the Y-axis direction.

  The positions and postures of the first to fourth light-emitting pixel arrays 3F to 3I so that the light-emitting pixels 30F to 30I of the first to fourth light-emitting pixel arrays 3F to 3I are distributed at equal intervals in the Y-axis direction as a whole. Is decided. For example, the first to fourth light emitting pixel arrays 3F to 3I are all arranged in the same posture and at equal pitches in the Y-axis direction.

  In this manner, by arranging the four light emitting pixel arrays 3F to 3I while being shifted in the Y-axis direction, the exposure light source 3 is arranged as compared with the case of the first embodiment shown in FIG. Therefore, the size of the space that must be secured can be reduced in the X-axis direction.

  In the sixth embodiment, the number of light emitting pixel arrays is four, but it may be two, three, or five or more. Furthermore, a plurality of exposure light sources according to any of the second to fifth embodiments may be arranged in the Y-axis direction.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

(A) is a front view of the direct drawing apparatus by 1st Example, (B) is a top view. It is a schematic perspective view of the exposure light source used for the direct drawing apparatus by the 1st Example. (A) And (B) is a schematic plan view of the exposure light source used for the direct drawing apparatus by the 1st and 2nd Example, respectively. (A) And (B) is a schematic plan view of the exposure light source used for the direct drawing apparatus by the 3rd and 4th Example, respectively. It is a schematic plan view of the exposure light source used for the direct drawing apparatus by the 5th Example. It is a schematic plan view of the exposure light source used for the direct drawing apparatus by the 6th Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 2 X stage 3 Exposure light source 3A-3J Light emitting pixel array 4 Control apparatus 10 Printed circuit board (exposure target object)
30A to 30J Light emitting pixels 31A to 31J Center line 32 Substrate 33 LED array 34 Driver circuit 35 Selfoc lens array

Claims (5)

When an XY Cartesian coordinate system is defined in which a photosensitive film holds an exposure object formed on the surface and a plane parallel to the surface of the held exposure object is defined as an XY plane, the held exposure object is defined in the X-axis direction. And a stage to move to
An exposure object including a plurality of light emitting pixels arranged in a first direction that is parallel to the XY plane and oblique to the Y-axis direction, and light emitted from each light emitting pixel is held on the stage And an exposure light source including a first light-emitting pixel array that sensitizes the photosensitive film.   The first light emitting pixel arrays are alternately arranged on a first side of a center line parallel to the first direction and an opposite second side in a plane parallel to the XY plane. The light emitting pixels arranged on the first side and the light emitting pixels arranged on the second side are both arranged in the first direction at the first pitch, and the light emission on the second side with respect to the first direction. The pixels are arranged at positions where the light emitting pixels on the first side are shifted by a half of the first pitch in the first direction, and the first and second light emitting elements adjacent to each other on the first side are arranged. When attention is paid to the pixel and the third light emitting pixel on the second side arranged between the pixels, the distance between the first light emitting pixel and the third light emitting pixel in the Y-axis direction, the second light emitting pixel, and the second light emitting pixel The first direction is inclined with respect to the Y axis so that the ratio of the distance between the three light emitting pixels and the distance in the Y axis direction is 1: (2n + 1) (n is a natural number). And has direct imaging system according to claim 1. The exposure light source further includes at least one second light emitting pixel array in which an arrangement pattern of a plurality of light emitting pixels is congruent with a light emitting pixel arrangement pattern of the first light emitting pixel array,
The first light emitting pixel array and the second light emitting pixel array are distributed at equal intervals in the Y-axis direction as a whole so that the light emitting pixels of the first light emitting pixel array and the second light emitting pixel array are distributed as a whole. The direct drawing apparatus according to claim 2, which is arranged.   The exposure light source further includes at least one second light emitting pixel array in which an arrangement pattern of a plurality of light emitting pixels is congruent with a light emitting pixel arrangement pattern of the first light emitting pixel array, and the second light emission 3. The direct drawing device according to claim 1, wherein the pixel array is arranged at a position obtained by translating the first light emitting pixel array in the Y-axis direction.   The light emitting pixels of the first light emitting pixel array and the light emitting pixels of the second light emitting pixel array are distributed at equal intervals in the Y-axis direction as a whole, and the first light emitting pixel array and the second light emitting pixel array The direct drawing apparatus according to claim 4, wherein a light emitting pixel array is arranged.

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