Side light apparatus of chip mounter and light apparatus using the side light apparatus

Provided are a light apparatus of a chip mounter which emits light to sides of a plurality of parts picked up by a plurality of nozzles of a chip mounter, the light apparatus including: at least one light module including a plurality of sloping portions each of which includes a plurality of slopes, wherein a slope of the plurality of slopes includes a light source emitting light to a side of a first part picked up by a first nozzle among the plurality of nozzles of the chip mounter.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from Korean Patent Application No. 10-2012-0028977 filed on Mar. 21, 2012 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

Apparatuses consistent with exemplary embodiments relate to a light apparatus of a chip mounter, and more particularly, to a side light apparatus of a chip mounter, in which each light source emits light to a side surface of not a spindle or nozzle located directly in front thereof but a spindle or nozzle located obliquely thereto in order to provide optimal lighting in a narrow space.

2. Description of the Related Art

With the development of electronic and communication technology, various electronic devices are becoming smaller and lighter. Accordingly, it is essential to make electronic parts (such as semiconductor chips) embedded in the various electronic devices highly integrated and ultra-small.

Small electronic parts are mounted on a printed circuit board (PCB) by a part mounter such as a chip mounter. There are thousands of types of electronic parts that can be mounted on a PCB by a chip mounter. Due to the high integration density and ultra-small size of such electronic parts, it is required to develop inspection and measurement technology for determining whether the electronic parts have been picked up and mounted on a PCB accurately.

To this end, various functions for ensuring the part-mounting quality of a chip mounter are being implemented. In particular, various methods of inspecting the picked-up state of a part to find a possible defect state in advance and enable accurate mounting are being implemented. These methods are broadly divided into two types: one is methods using pneumatic pressure and the other is methods using images.

The methods using pneumatic pressure suffer from a high frequency of false defects due to the state of nozzles, whether parts have been picked up by the nozzles, and the instability of reference pneumatic pressure. Therefore, the methods using images are preferred. In a related art method using images, an image capture device is placed directly under a nozzle to capture an image of the nozzle and determines whether a part has actually been picked up by the nozzle using the captured image of the nozzle. To clearly capture the image of the part, light is projected onto the part.

To accurately recognize edge lines of parts, part mounting equipment mostly emits light from sides of the parts. In particular, to recognize parts with round or sphere edges (not sharp edges), the part mounting equipment forms a circular or square shape around a focus at which a part is to be recognized and emits light to the part, thereby revealing edges of the part.

FIG. 1Ais a diagram illustrating an example part picked up by a chip mounter.FIG. 1Bis a diagram illustrating a related art chip mounter which captures an image of a part picked up by a nozzle using a camera.FIG. 1Cis a diagram illustrating a related art light apparatus which emits light to a picked-up part.FIG. 1Dshows an image of a part captured by the camera.

An ultra-small part such as a flipchip does not have leads but has a plurality of protrusions called “balls.” Referring toFIG. 1A, a part5includes a plurality of balls6. The part5is picked up by a chip mounter and mounted on a PCB.

Referring toFIG. 1B, a head10of the chip mounter includes one or more nozzles12which pick up parts5. The head10may be circular or square. To pick up the parts5, the head10may move vertically and horizontally while rotating. The nozzles12may be arranged at regular intervals in the head10, supported respectively by spindles11, and connected to the head10. A camera20is placed on a side of or under the head10and captures an image of a side surface or a bottom surface of a part5and a spindle11. Then, the camera20analyzes the captured image of the part5and obtains information about the length, width, twisted angle and position of the part5.

After the part5is picked up, light should be projected not only onto a top or bottom surface of the part5but also to side surfaces of the part5. Only then can balls6located on the bottom surface of the part5be clearly “vision-recognized,” and thus edges of the part5can be recognized clearly. Here, “vision recognition” is to capture and obtain an image of the part5using the camera20or display an image of the part5seen through a lens. Vision recognition is a concept corresponding to the recognition of an object with human eyes.

Therefore, for accurate recognition of edge lines of the part5, light is projected not only onto the top and bottom surfaces of the part5but also onto the side surfaces of the part5. Referring toFIG. 1C, a top light source31and a bottom light source33are placed above and under the part5to emit light to the top and bottom surfaces of the part5. In addition, side light sources35-1and35-2are located on left and right sides of the part5to emit light to both side surfaces of the part5, respectively. Accordingly, not only the edges of the part5but also the balls6of the part5can be recognized accurately.

Referring toFIG. 1D, when the part5is located at the focus of the camera20, if light is projected onto the side surfaces of the part5, an image in which the balls6of the part5look like donuts can be obtained. Also, the presence or absence of the balls6of the part5can be identified in the image.

To increase the speed of part mounting equipment such as a chip mounter and reduce the weight of the chip mounter, the gap between spindles11of a head10of the chip mounter is being reduced, and more spindles11are being arranged in an outer region of the head10. In this structure, however, side lights cannot be arranged in a row or a circular shape due to the limited space in which the side lights for accurately recognizing the edges of parts5are installed.

For example, if the side lights are arranged in a row, the size of a region where the parts5are to be mounted may be reduced. In addition, if one recognition device (e.g., a camera) recognizes each part5of the head10one by one, there is no problem with light uniformity. However, if the recognition device recognizes two or more parts5, a part5on the left or right side of a spindle11at each end of the head10, that is, the outermost part5may appear dark due to the interference between the side lights.

SUMMARY

One or more exemplary embodiments provide a side light apparatus of a chip mounter, the light apparatus including a plurality of light sources and capable of providing optimal lighting in a narrow space to parts picked up by a plurality of nozzles of the chip mounter while each light source of the light apparatus emits light to a side of not a part located directly in front thereof but a part next to the part located directly in front thereof.

One or more exemplary embodiments also provide a light apparatus of a chip mounter which can recognize edges of parts and obtain image information of balls of each part accurately since emitted light is reflected by a pair of mirrors installed at both ends of the light apparatus to enter outermost ones of parts picked by spindles of the chip mounter.

However, the exemplary embodiments described herein do not restrict the inventive concept thereto.

According to an aspect of an exemplary embodiment, there is provided a light apparatus to emit light to sides of a plurality of parts picked up by a plurality of nozzles of a chip mounter, respectively, the light apparatus including: at least one light module including a plurality of sloping portions each of which includes a plurality of slopes, wherein a slope of the plurality of slopes includes a light source emitting light to a side of a first part picked up by a first nozzle among the plurality of nozzles of the chip mounter.

The light apparatus may further include a mirror, wherein the light module includes another at least one sloping portion disposed around at the mirror, and a slope of the other at least one sloping portion comprises a light source emitting light to the mirror which reflects the light incident on the mirror to a side of a second part picked up by a second nozzle among the plurality of nozzles of the chip mounter located around at the mirror.

In the light apparatus, the first nozzle may be located second-closest to the light source emitting the light to the side of the first part, among the plurality of nozzles, and faces a slope of a sloping portion of the light module which comprises the light source emitting the light to the side of the first part.

In the light apparatus, an additional light source may be disposed between two neighboring sloping portions located closest to the first nozzle, among the plurality of sloping portions, and emits light to the side of the first part picked up by the first nozzle.

The light sources included in two slopes, of the two neighboring sloping portions, facing each other may emit light to parts, among the plurality of parts, picked up by two nozzles, respectively, right next to the first nozzle.

The light source may emit the light to the side of the first part at an angle of 30 to 60 degrees with respect to a lengthwise direction of the light module.

A color of the light emitted to the side of the first part may be identical or similar to a surface color of the light module.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The inventive concept will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown.

FIG. 2is a perspective view of a side light apparatus100for the chip mounter shown inFIG. 1B, according to an exemplary embodiment.FIG. 3is a diagram illustrating directions of light emitted from the side light apparatus100ofFIG. 2to the nozzles12of the chip mounter. Here, the directions of the light emitted from the side light apparatus100are perpendicular to a direction of vertical movement of the spindles11and the nozzles12of the chip mounter.FIG. 4is a diagram illustrating a lateral view of the side light apparatus100ofFIG. 1which emits light to parts5picked up by the chip mounter.

The side light apparatus100of the chip mounter emits light to sides of the parts5for recognition of the parts5in the chip mounter. The side light apparatus100may include a frame110, a pair of side light modules120which face each other, and a pair of mirrors130which face each other. SinceFIG. 2is a perspective view of the side light apparatus100, only one of the side light modules120is shown as being disposed along with one lengthwise side of the frame110. The other side light module120is not shown inFIG. 2since it is disposed behind the other lengthwise side of the frame110inFIG. 2.

The frame110serves as a housing which houses the side light modules120and the mirrors130. When the spindles11and the nozzles12of the chip mounter shown inFIG. 1Bmoves inside the frame110, light is provided to the parts5picked up by the nozzles12using the side light modules120and the mirrors130.

The side light modules120may be located at both sides and inside the frame110, respectively. The side light modules120may be disposed along the two lengthwise directions of the frame110, respectively, and have a plurality of saw-tooth portions121connected to one another. At least one light source122is disposed at each slope of a saw-tooth portion121and emits light to a side surface of one of the parts5picked up by the nozzles12of the chip mounter.

That is, a surface of each side light module120extends in a lengthwise direction and is saw-toothed, and at least one light source122is disposed at each slope of a saw-tooth portion121of each side light module120to provide light. Accordingly, each light source122included in each side light module120does not emit light to a part5picked up by a nozzle12located closest to the each light source122. Instead, each light source122emits light to a part5picked up by a nozzle12located second-closest to the each light source122among the plurality of nozzles12and facing a slope of a saw-tooth portion121where the each light source122is disposed.

Therefore, the side light modules120emit light to the side surfaces of the parts5not perpendicularly but at a predetermined angle with respect to the lengthwise direction of each side light module120. The predetermined angle may be 30 to 60 degrees, preferably but not necessarily, 45 degrees due to the saw-tooth portions121of each side light module120.

The light sources122are included in the side light modules120and emit light to the nozzles12included in the head10of the chip mounter and to the side surfaces of the parts5picked up by the nozzles12. For example, the light sources122may be light-emitting diode (LED) devices. The LED devices used as the light sources122may be side-view LEDs. The side-view LEDs may be installed in the side light modules120and may emit light from a slope of each saw-tooth portion121at an angle of 90 degrees.

A surface color of each side light module120in which one or more light sources122are located may be linked to a color of light emitted from the light sources122. That is, when the light sources122emit red light, each side light module120or a reflective member (not shown) attached to a top plate of the side light module120may be red or similar colors. For example, when the light sources122emit white light, each side light module120or the reflective member attached to the top plate of the side light module120may be white, yellow, or red.

As described above, two side light modules120face each other where each side light module120is saw-toothed. Further, at least one light source122is located at each slope of a saw-tooth portion121of each side light module120. Therefore, the light sources122emit light in directions that cross each other, thereby making side edges of the parts5clearly visible. Accordingly, parts with a circular (not square) shape can be recognized accurately, and circular balls included in each part can also be recognized accurately.

The mirrors130may be located at both sides of the frame110where the side light modules120are not located. Accordingly, the mirrors130and the side light modules120may form a space with a rectangular cross section. Light emitted from light sources122located at both ends of each side light module120may be reflected by the mirrors130to enter the parts5picked up by nozzles12at both ends of the chip mounter.

That is, the mirrors130are installed at left and right ends of the side light apparatus100of the chip mounter to reflect light, emitted from light sources122and incident on the mirrors130, to the side surfaces of the parts5picked up by nozzles12at both ends of the chip mounter. Accordingly, the light can be provided to the side surfaces of the parts5picked up by the nozzles12at both ends of the chip mounter where light generally fails to reach. The provided light makes side edges of the parts5more visible.

Referring toFIGS. 3 and 4, the side light apparatus100of the chip mounter emits light to the side surfaces of the nozzles12from four directions. Thus, the side edges of the parts5picked up by the nozzles12can be observed clearly. In addition, light emitted from light sources122at both ends of each side light module120is reflected by the mirrors130to enter the parts5picked up by outermost nozzles12located at both ends of the chip mounter. Therefore, the side edges of the parts5picked up by the nozzles12at both ends of the chip mounter can be observed clearly.

When the side light apparatus100of the chip mounter is configured as described above with reference toFIGS. 2 through 4, more light sources122can be installed in the same area. This enables a reduction in the distance between the spindles11or between the nozzles12. Accordingly, more spindles11and/or more nozzles12can be installed in the same area of the head10.

FIG. 5is a diagram illustrating a schematic configuration of a light apparatus50of a chip mounter according to another exemplary embodiment.

The above-described side light apparatus100in reference toFIGS. 2-4can be expanded to the light apparatus50of the chip mounter.

Compared to the side light apparatus100, the light apparatus50includes additional light sources142,152emitting light to the side surfaces of the parts5for recognition of the parts5in the chip mounter. Each of the light sources142is disposed between two neighboring saw-tooth portions121of one side light module120, and each of the light sources152is disposed between two neighboring saw-tooth portions121of the other side light module120. Thus, each of the light sources142,152emits light to a side surface of a part5picked up by a nozzle12located closest to the each of the light sources142,152among the plurality of nozzles12. Here, the side light modules120and the mirrors130play the same roles as the side light modules120and the mirrors130of the above-described side light apparatus100of the chip mounter.

LED devices may also be used as the light sources142and152. The number of light sources142or152included in each of the side light modules120may be equal to the number of nozzles12installed in the head10of the chip mounter. However, it is obvious to those of ordinary skill in the art that the present embodiment does not limit the inventive concept.

The side light modules120emit light to the side surfaces of the parts5and may be provided in a pair as discussed above. When the side light modules120are provided in a pair, they may be, but are not limited to, symmetrical to each other.

As described above, a side of each side light module120is saw-toothed, and at least one light source122is disposed at each slope of each saw-tooth portion121and emits light to a side surface of one of the parts5at a predetermined angle with respect to the lengthwise direction of each side light module120. The predetermined angle may be 30 to 60 degrees, preferably but not necessarily, 45 degrees.

Referring toFIG. 5, the light apparatus50of the chip mounter emits light to a part5picked up by one nozzle12from at least six directions. A light source142disposed between two neighboring sub-modules121of one side light module120emits light to a side surface of a part5located closest to the light source142. Here, this part5may be located directly in front of the light source142. Also, a light source152disposed between two neighboring sub-modules121of the other side light module120emits light to an opposite side surface of the part5. Since the light apparatus50includes these light sources142,152in addition to the light sources122, the parts5picked up by the nozzles12except the nozzles12located at both ends of the side light module120are illuminated by light from six directions. Thus, edge lines of each of the parts5can be recognized more accurately.

If the light sources142,152and122have the same luminous intensity, light emitted to the side surfaces of a part5from the light sources142,152may be more intense than light emitted from the light sources122because the light sources142,152are disposed more close to the part5than the light sources122emitting light to the part5. For this reason, the light sources142and152may be placed further away from the part5than the light sources122, so that the part5can receive light of the same intensity from any direction, according to an exemplary embodiment.

The luminous intensities of the light sources142,152and122can be adjusted by using different electrical powers or LED ranks, according to an exemplary embodiment.

The mirrors130may be installed at both sides of the light apparatus50where the side light modules120are not located. As described above, light emitted from light sources122located at both ends of each side light module120may be reflected by the mirrors130to enter the parts5picked up and picked up by nozzles12at both ends of the chip mounter.

Referring toFIG. 5, the light apparatus50of the chip mounter emits light to a part5picked up by one nozzle12from at least six directions. Also, a nozzle12at each end of the chip mounter receives light reflected by a mirror130located on a left or right side of the nozzle12.

Therefore, more light sources122,142and152can be installed in the same area of the light apparatus50of the chip mounter. Accordingly, more spindles11can be installed in the same area of a head10, and the light apparatus50of the chip mounter can be designed to be slim.

According to the above exemplary embodiments, optimal side lighting can be provided in a narrow space. Therefore, whether a part has been picked up accurately can be determined regardless of the shape of the part.

In addition, light can be projected onto a part in a narrow space using mirrors. Therefore, edges of the part can be recognized, and position information of balls of the part can be obtained. Accordingly, the part and the balls can be recognized accurately and quickly.

Furthermore, since a light apparatus can be designed to provide optimal lighting in a narrow space, costs can be saved, and the productivity of a chip mounter can be improved.

Thus far, various exemplary embodiments have been described in reference to the drawings. However, these embodiments are provided only for illustrative purposes without limiting the inventive concept. For example, the number of the side light modules120inFIGS. 2,3and5is not limited to two, and instead, only one side light apparatus120may be disposed along one side of the frame110of the side light apparatus100or50. Also, the number of the light sources122disposed at each slope of a saw-tooth portion121is not limited to one, and the number of the light sources142or152disposed between two neighboring saw-tooth portions121is not limited to one. Two or more light sources122,142or152may be disposed at corresponding portions of the side light apparatus120. Also, the number of the mirrors130is not limited to two, and instead, only one mirror130may be provided at one end of the side light apparatus120. Also, the saw-tooth portions121may take a different form not being limited only to the saw-tooth form. Thus, those skilled in the art will appreciate that various modifications, additions and substitutions are possible without departing from the spirit and scope of the inventive concept as defined by the accompanying claims.