JP5538707B2 - Lighting device - Google Patents

Description

  The present invention relates to an illuminating device mounted on a printed circuit board inspection apparatus or the like, and more particularly to an illuminating apparatus capable of efficiently irradiating light to an inspection object such as a printed circuit board. Is.

  Generally, an illumination device for irradiating light to an inspection object is attached to an inspection device that inspects a printed circuit board. This illuminating device is configured by providing a plurality of LEDs directed toward an inspection object, and irradiates the inspection object with light from the plurality of LEDs, and receives the reflected light with a line sensor for printing. The surface image can be acquired from the substrate.

  By the way, regarding such an illuminating device, there are those described in Patent Document 1 below.

  For example, Patent Document 1 discloses an illumination device in which a plurality of rows of LEDs are embedded in a mounting board having an elongated rectangular shape, and lenses for collecting light from these LEDs are provided. .

Patent Document 2 discloses an illumination device in which a row of LEDs embedded in a mounting substrate are arranged in an arc shape, and light is emitted from these LEDs toward a central portion. In addition to these patent documents, there are a large number of illumination devices in which a plurality of LEDs are attached toward the arcuate central portion.
JP 2007-010380 A JP 2006-075836 A

  By the way, when an LED is attached to such a lighting device, the following problems occur.

  That is, in the method of attaching a plurality of rows of LEDs to a single mounting board as in the former and arranging the LEDs in a circular arc shape on the bracket, all the LEDs in one mounting board are oriented in one direction. Cannot be directed to the center of the arc. Therefore, when the reflected light is received by the line sensor, there arises a problem that the light intensity in the inspection line is insufficient.

  On the other hand, in the method of attaching a row of LEDs to a single mounting board as in the latter and arranging them in a circular arc shape on the bracket, the LEDs on the mounting board can be directed to the inspection line. However, in actuality, an extra space is required to attach each mounting board to the bracket, and a wasteful space is created in the left-right width direction of each LED, so the number density of LEDs per mounting board Less. For this reason, the attachment efficiency of LED to a mounting board | substrate will worsen, and it will cause the lack of luminous intensity in an inspection line. Furthermore, since the number of mounting boards increases, the work for attaching the mounting boards to the brackets becomes difficult.

  Therefore, the present invention has been made paying attention to such a problem, and when irradiating light on an inspection object, the light from each LED can be efficiently directed to the inspection line, and the mounting substrate is used as a bracket. It is an object of the present invention to provide an illumination device that can simplify a work process for attachment.

That is, in order to solve the above-described problem, the present invention provides an illumination device for an inspection apparatus that irradiates an inspection object with light and receives a reflected light from an inspection line of the inspection object with a line sensor. A mounting board having a plurality of rows of LEDs mounted in a direction along the inspection line; and a bracket for mounting a plurality of the mounting boards. The second row of LEDs and the heads of the LEDs on each mounting board. together to position the LED head of the first column between the parts, it positions the LED head of the second column between the head of the LED and LED of the first row and the first column In addition, the legs of the LEDs in the second row are inclined in the longitudinal direction and the short direction of the mounting substrate so that the optical axes of all the LEDs are directed to the inspection line.

  In this way, many LEDs can be mounted densely on a single mounting board, so that the irradiation efficiency can be improved and all optical axes are directed to the inspection line. In this case, it is possible to perform an accurate inspection. In addition, since a plurality of rows of LEDs are attached to one mounting substrate, the work process for attaching the mounting substrate to the bracket can be simplified. Furthermore, it is possible to detect scratches provided in various directions by irradiating light from various directions.

  Further, in such an invention, the LEDs in each row are attached to attachment holes provided so as to be opposed to the longitudinal direction of the mounting substrate in an oblique direction.

  In this case, it becomes unnecessary to set the optical axes of the respective LEDs, and the optical axes of all the LEDs can be directed to the inspection line at a time.

  According to the present invention, many LEDs can be mounted densely on a single mounting board, so that the irradiation efficiency can be improved and all optical axes are directed to the inspection line. In this case, it is possible to perform an accurate inspection. In addition, since a plurality of rows of LEDs are attached to one mounting substrate, the work process for attaching the mounting substrate to the bracket can be simplified. Furthermore, it is possible to detect scratches provided in various directions by irradiating light from various directions.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of an illumination device 2 mounted on a printed circuit board inspection apparatus 1 according to an embodiment of the present invention. FIG. 2 shows a leg mounting hole 26a of the mounting substrate 26. This shows the state. 3 and 4 are side views as seen from the short side and the long side in FIG. 1, and FIG. 5 is a plan view of the mounting board 26 in FIG.

  In the illuminating device 2 according to this embodiment, a plurality of rows of LEDs 23 are attached to a mounting board 26 having an elongated rectangular shape, and the mounting board 26 is attached to an inner side of an arc-shaped bracket 27 on the inspection line 5 of the line sensor 3. Specifically, the first row LED group 21 and the second row LED group 22 are provided in the longitudinal direction of the rectangular mounting board 26, and the leg portions 24 of these LEDs 23 are provided. Is bent so that the optical axis is directed toward the inspection line 5 at the center of the arc. And the reflected light from the printed circuit board 4 which is a test object is received by the line sensor 3 so that the formation state of the printed circuit board 4 can be inspected. Hereinafter, a specific configuration of the illumination device 2 will be described in detail.

  The LED 23 attached to the mounting substrate 26 is a relatively small one. The LED 23 is attached so that the leg portion 24 stands from the mounting substrate 26, and is attached so that the optical axis can be directed to the inspection line 5 by bending the leg portion 24 that stands. By the way, when the LED 23 is attached to the mounting substrate 26 in this way, when the gap between the first row LED group 21 and the second row LED group 22 becomes very narrow, the heads 25 of the respective LED 23 come into contact with each other to inspect the optical axis. Can no longer be directed to line 5. On the other hand, when the gap between the first row LED group 21 and the second row LED group 22 is increased, the number of LEDs 23 with respect to the mounting substrate 26 is reduced, resulting in wasted space and irradiation efficiency. Therefore, when the LED 23 is attached, as shown in FIG. 5, the head 25 of the LED 23 in the second row LED group 22 is positioned between the LED 23 in the first row LED group 21 and the head 25 of the LED 23. Tilt. That is, when the LED 23 is attached, the leg attachment holes 26a of the first row LED group 21 and the second row LED group 22 are set in the same position and direction as shown in FIG. The legs 24 are bent in the row direction and the width direction with the center at the center. In this way, the head 25 of the first LED group 21 can be positioned between the LED 23 and the LED 23 in the second LED group 22, and the gap in the LED group column direction is narrowed. Also, the leg portions 24 can be bent in the width direction and the column direction.

  Further, when the leg portions 24 of the LEDs 23 are bent as described above, there are cases where the two leg portions 24 of each LED 23 cannot be bent greatly in the direction in which they are arranged side by side. Therefore, as shown in FIG. 6, the leg mounting holes 26a of the LEDs 23 can be provided so as to face each other in an oblique direction, and the LEDs 23 can be bent in a direction perpendicular to the direction of the leg mounting holes 26a. In this way, when bending, the LED 23 can be easily bent without applying a large load to the leg portion 24, and further, the LED 23 can be bent in the diagonal direction and directed in the width direction and the column direction. Thus, the LED 23 can be bent.

  Alternatively, instead of bending the leg portion 24 after attaching the LED 23 in this way, the LED 23 can be attached to the mounting substrate 26 in an inclined state when attached to the mounting substrate 26. When attaching to the mounting substrate 26 in this way, the LED 23 is inserted into the leg attachment hole 26a from an oblique direction and soldered, and thereafter, if necessary, the leg 24 is bent to finely adjust the angle.

  Further, when the LED 23 is attached to the mounting substrate 26, the legs 24 may be attached with the same length so that the distance between the inspection line and the head portion 25 of the LED 23 is constant. Such a method is effective when the radius of curvature up to the LED 23 with the inspection line as the center line is small.

  The mounting board 26 configured in this manner is attached to the inside of the arc-shaped bracket 27. The bracket 27 is composed of a pair of bracket elements that hold both ends of the mounting substrate 26 in the longitudinal direction, and has a flat portion 28 for attaching the mounting substrate 26 to an inner surface having an arc shape ( FIG. 1). The flat portion 28 has a width dimension substantially the same as the width dimension of the mounting board 26 in the short direction, and when the mounting board 26 is attached via a fixing member such as a screw, the normal line of the mounting board 26 is obtained. The direction is matched with the direction of the inspection line 5. Such flat portions 28 are provided on all of the inner peripheral surface having an arc shape, and the mounting substrate 26 is attached to all portions except the top. On the other hand, a CCD line sensor 3 is mounted above the top, and receives reflected light from the inspection line 5 which is the center of the arc. When the mounting substrate 26 is attached to such a bracket 27, if the short dimension of the mounting substrate 26 is short, if an error occurs in the thickness dimension, the normal direction is the direction of the inspection line 5 due to the influence of the error. No longer turn to. However, if two rows of LEDs 23 are provided as in the present embodiment, the width dimension in the short side direction is increased, and the error of the thickness dimension can be absorbed to reduce the fluctuation of the optical axis.

  The case where light is irradiated to the printed circuit board 4 which is a test object from the illuminating device 2 comprised in this way is demonstrated.

  First, when the printed circuit board 4 is conveyed inside the illumination device 2, light is emitted from the LEDs 23 of each mounting substrate 26. At this time, instead of irradiating light from all the LEDs 23 at the same time, irradiating light sequentially from each mounting substrate 26, or even within each mounting substrate 26, the first row LED group 21 and the second row LED group 22 Irradiate light in a different order. In this case, for example, as shown in FIGS. 8A and 8B, all LEDs 23 on the inspection line 5 are present even when there are scratches perpendicular to the optical axis direction or scratches parallel to the optical axis direction. As shown in FIG. 8A, the scratches are not darkened or the scratches in a specific direction cannot be detected. That is, as shown in FIGS. 8A and 8B, even if there is a scratch in a direction perpendicular to the inspection line 5 (left and right direction in FIG. 8), the first row LED group 21 and Since the optical axis of the second row LED group 22 is inclined, the scratches can be conspicuous. Moreover, since the optical axes of all the LEDs 23 coincide with the inspection line 5, the reflected light from the scratch can be increased.

As described above, according to the embodiment, in the illumination device 2 in the inspection apparatus 1 that irradiates the printed circuit board 4 with light and receives the reflected light from the inspection line 5 on the printed circuit board 4 by the line sensor 3, 4, one mounting board 26 to which a plurality of rows of LEDs 21 and 22 are attached in a direction along the inspection line 5, and a bracket 27 for attaching a plurality of the one mounting board 26. The head 23 of the LED 23 in the first row is positioned between the LED 23 in the second row and the head 25 of the LED 23, and the head of the LED 23 in the second row is located between the LED 23 in the first row and the head 25 of the LED 23. The portion 25 is positioned, and the legs 24 of the LEDs 23 in the first row and the second row are inclined in the longitudinal direction and the short direction of the mounting substrate, so that all the LEDs 23 Since the optical axis and to direct the inspection line 5, it is possible to perform an accurate test on the inspection line 5. In addition, since a plurality of rows of LEDs 23 are attached to one mounting board 26, the work process for attaching the mounting board 26 to the bracket 27 can be simplified.

  In such an invention, the LEDs 23 in each row are attached to the leg mounting holes 26a provided so as to be opposed to the longitudinal direction of the mounting substrate 26 in an oblique direction. There is no need to set each optical axis, and the optical axes of all LEDs 23 can be directed to the inspection line at a time.

  In addition, this invention is not limited to the said embodiment, It can implement in a various aspect.

  For example, in the above-described embodiment, the first row LED group 21 and the second row LED group 22 are provided. However, the number of rows is not limited to two, and three or more rows are formed on one mounting substrate 26. The LED group may be provided. In this case, the LED groups in the center row are preferably provided perpendicular to the mounting substrate 26, and the left and right LED groups are preferably inclined toward the center row side. Also in this case, the column direction angles of the left and right LED groups may be set differently.

  In the above embodiment, the mounting board 26 is attached to the arcuate bracket 27. However, the mounting board 26 is not limited to the arcuate shape, and any mounting board can be attached to the inspection line 5. Any shape may be used.

  In the above embodiment, the LED 23 is bent or inclined to be directed toward the inspection line 5. However, as shown in FIG. 9, the mounting substrate 26 itself is curved along the bracket 27b, thereby changing the optical axis. You may make it unify. As such a method, the mounting substrate 26 may be formed of a flexible substrate, and the mounting substrate 26 may be attached along the inner side surface of the bracket 27b forming an arc shape. In this case, it is not possible to form a curve at the central portion in the longitudinal direction of the mounting substrate 26 by fixing only both ends of the mounting substrate 26. For this reason, it is preferable to provide a bracket element on the entire surface of the mounting substrate 26 or intermittently, thereby forcibly bending the mounting substrate 26. In this way, the optical axes of the plurality of LEDs 23 can be unified at a time, and the work process can be simplified.

  Furthermore, in the above embodiment, the case where the printed circuit board 4 is inspected has been described. However, the present invention is not limited to the printed circuit board 4, and it is possible to inspect scratches and formation states from liquid crystal substrates, semiconductor wafers, and other appearance images. It can be applied to all inspection objects.

Schematic of the lighting device in the embodiment of the present invention The figure which shows the leg part attachment hole of LED of the mounting board in the same form Side view of the board with the LED in the same form as seen from the short side Side view seen from the longitudinal direction of the substrate to which the LED in the same form is attached Plan view of mounting board with LED in same form The figure which shows the leg part attachment hole of LED of the mounting board in other embodiment. The figure which shows the state which irradiated the light from the illuminating device in the same form The figure which shows the state which irradiated the light from the illuminating device in the same form Examples of lighting devices in other embodiments

DESCRIPTION OF SYMBOLS 1 ... Printed circuit board inspection apparatus 2 ... Illumination device 21 ... 1st row LED group 22 ... 2nd row LED group 23 ... LED
24 ... Leg 25 ... Head 26 ... Mounting board 26a ... Leg mounting hole 27 ... Bracket 27a ... Bracket element 28 ... Flat part 3 ... Line sensor 4 ... Printed circuit board 5 ... Inspection line

Claims (2)

In the illumination device of the inspection apparatus that irradiates the inspection object with light and receives the reflected light from the inspection line in the inspection object with a line sensor,
One mounting board in which a plurality of rows of LEDs are attached in a direction along the inspection line of the inspection object;
A bracket for mounting a plurality of the one mounting board,
The head of the first row of LEDs is positioned between the LED of the second row and the head of the LED on each mounting substrate, and the second row of LEDs is located between the LED of the first row and the head of the LED. The heads of the LEDs are positioned, and the legs of the LEDs in the first row and the second row are inclined in the longitudinal direction and the short direction of the mounting substrate so that the optical axes of all the LEDs are directed to the inspection line. A lighting device characterized by the above. The lighting device according to claim 1, wherein the LEDs in each row are attached to attachment holes provided so as to face each other in an oblique direction with respect to the longitudinal direction of the mounting substrate.

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