ILLUMINATING AND OPTICAL APPARATUS FOR INSPECTING SOLDERING OF PRINTED CIRCUIT BOARD

Abstract: An illuminating and optical apparatus for inspecting soldering of PCB of the present invention comprises: a fixed member which forms a horizontal plane at the top thereof and a tilted plane at the side thereof; first illuminating means disposed at the upper plane of the fixed member for illuminating the inspecting part attached on the PCB; second illuminating means disposed at the tilted plane of the fixed member for illuminating the inspecting part to obtain an image whose shade is inverted to that obtained by the first illuminating means; control means for controlling brightness of the first and second illuminating means and turning on/off of power; and optical means disposed at the upper portion of the fixed member for photographing at large and small views the inspecting part illuminated by the first and second illuminating means under the control of the control means, thereby automatically inspecting the mounted and soldered states of various electronic parts on the surface of a printed circuit board of a surface mounting apparatus by evenly illuminating and photographing with an adequate view in accordance with the size thereof.

Description: ILLUMINATING AND OPTICAL APPARATUS FOR INSPECTING SOLDERING OF PRINTED CIRCUIT BOARD Technical Field The present invention relates to an illuminating and optical apparatus for inspecting soldering of a printed circuit board, and more particularly to the illuminating and optical apparatus which uniformly illuminate and photograph a variety of electronic parts mounted and soldered on the printed circuit board of a surface mounting apparatus, to thereby automatically inspect the mounted and soldered states thereof. Background Art In general, a surface mounting apparatus is used for automatically fixing a variety of electronic parts such as integration element, resistor, condenser and the like by directly soldering on the printed circuit board (hereinafter referred to as PCB). That is. without separate soldering lead wires to fix on the PCB. those electronic parts have electrodes for directly soldering the electrodes. In this way. there will be advantages such as reducing the size of electronic parts, substantially improving assembling and manufacturing speed because a separate hole does not have to be formed for fixing electronic parts on the PCB, and decreasing the size of a product. In soldering various parts with the surface mounting apparatus, the parts are so small that they can not be accurately mounted on the PCB or the amount of solder is so great that the potential may be high for two adjacent electrodes to bring about a lot of errors such as short circuit and the like. Therefore, after finishing up soldering parts. mounted and soldered states thereof are inspected to decrease a defective rate of products. In order to inspect the mounted and soldered states of the parts soldered at the surface mounting apparatus, a number of workers are needed for manual inspection, but it is hard to achieve uniformity of the manual inspection. Therefore, in case of inspecting the mounted and soldered state of the part soldered on the PCB. an automatic inspection process has been performed by illuminating, and photographing the inspecting parts with a camera and screening the mounted and soldered states of the parts with resultant photographs. FIG. 1 is a schematic view for illustrating an embodiment of the structure and operational state of a conventional illuminating and optical apparatus which illuminates and photographs the mounted and soldered states of the electronic part on the PCB for automatic inspection. At this time, reference numeral 10 denotes the PCB. Reference numeral 1 1 denotes an electronic part such as integration element, resistor and condenser and the like, whose mounted and soldered states on the printed circuit board are inspected. Also, reference numeral 12 denotes a disturbing part adjacently positioned to the inspecting part soldered on the PCB, which interferes the proceeding route of the light in inspecting the mounted and soldered states of the part on the PCB. Reference numerals 13. 14, and 15 respectively denote upper, middle and lower light emitting parts, all of which illuminate the inspecting part 1 1. All of those light emitting parts are made up of a plurality of lamps arranged in the ring shaped fixtures of different diameters and different heights therebetween. Symbols HI . H2 and H3 respectively denote the height of the upper, middle and lower light emitting parts 13, 14, 15 arranged at different heights having the relationship of H1>H2> H3. On the other hand, symbols Dl . D2 and D3 respectively denote the diameter of the upper, middle and lower light emitting parts 13. 14. 15 arranged at different diameter having the relationship of D1>D2>D3. All of those light emitting parts 13. 14. 15 are fixed with an identical center thereof. At this time, for instance, light emitting diodes are used for a plurality of lamps. Reference numerals 16, 17 respectively denote a camera and lenses thereof positioned over the center axis of all the upper, middle and lower emitting parts 13, 14, 15 for photographing the inspecting part 1 1 while being illuminated by the upper, middle and lower light emitting parts 13, 14, 15. For example, the camera 16 takes a photograph of the inspecting part 1 1 with a charged coupled device CCD. When an embodiment of the conventional illuminating and optical apparatus thus constructed is used for inspecting the mounted and soldered states of the part 1 1 on the PCB 10, all the lamps of the upper, middle and lower light emitting parts 13, 14, 15 are turned on to illuminate the inspecting part 1 1. At this state, the camera 16 takes an image of the inspecting part 1 1 illuminated by the upper, middle and lower light emitting parts 13, 14, 15 through the lenses 17. The photographed image of the inspecting part 10 is inputted and further processed at an inspection apparatus like an inspection computer system or the like to definitely inspect the mounted and soldered states of the part 1 1 on the PCB 10. However, in case of the aforementioned embodiments of the conventional illuminating and optical apparatus, the incident light of the upper, middle and lower light emitting parts 13. 14. 15 is focused only on a position of the inspecting part 1 1. that is, at the center of a photographing view of the camera 16. As a result, the center of the photographed image is brightest. On the other hand, the closer a position gets to the edge of the image, the darker the image is. Therefore, as an image processing condition should be differently set up depending on positions of the same image of an identical inspecting part 1 1. it is difficult to make a standard inspection condition. FIG. 2 is a schematic view for illustrating another embodiment of the structure and operational state of the conventional illuminating and optical apparatus. As shown in FIG. 2. the illuminating and optical apparatus includes light diffusers 13a. 14a, 15a below the upper, middle and lower light emitting parts 13. 14, 15. In case of the second embodiment of the conventional illuminating and optical apparatus thus constructed, light illuminated by the upper, middle and lower light emitting parts 13, 14. 15 are diffused by the light diffusers 13a, 14a. 15a. thereby relatively evenly illuminating the inspecting part 11. However, as the illuminating light is diffused, the amount of light actually directed to the inspecting part 11 has substantially decreased. Therefore, it is difficult to adequately illuminate the inspecting part 1 1 for inspection. In addition, since the diffusion degree of light varies in response to the quality of the material of the diffuser, it is difficult to evenly illuminate the inspecting part 11 for inspection up to the required level. Besides the aforementioned problems, there are further problems, which will be described below, in the aforementioned embodiments of the conventional apparatus in accurately inspecting the mounted and soldered states of the inspecting part 11. First of all, as only the upper, middle and lower light emitting parts 13, 14, 15 are used for illuminating and photographing the inspecting part 1 1. it has been difficult to distinguish a soldering portion of the inspecting part 11 from a pattern of the PCB 10 or the body of the inspecting part 11 , or the electrode of the inspecting part 1 1 from the body of the inspecting part 11 or the soldering portion. Therefore, it is difficult to simultaneously inspect both of the mounted and soldered states of the inspecting part 11. Secondly, if the disturbing matter 12 positioned around the inspecting part 1 1 is larger than the inspecting part 1 1 itself, the light emitted by the lower light emitting part 15 tends to be interfered or blocked by the disturbing matter 12. causing a light interference phenomenon. Therefore, the required illumination effect can not be obtained, thereby reducing reliability of the inspection process. Thirdly, there is no control means available for controlling brightness of the upper, middle and light emitting parts 13. 14. 15. thereby causing inconveniences in use. Fourthly, a single size of the camera view is available for grasping the inspecting state. In other words, only camera 16 is utilized at an identical magnitude for photographing the inspecting part 1 1. Therefore, it is impossible to adequately correspond to different sizes of the inspecting part 11 , thereby reducing the inspecting speed. Disclosure of Invention It is an object of the present invention to provide an illuminating and optical apparatus for inspecting soldering of PCB, comprising a plurality of light emitting parts which evenly illuminate an inspecting part and two cameras set at different magnitudes which photograph the inspecting part efficiently corresponding to changes in size, thereby improving inspecting speed and reliability of the inspection process. In order to accomplish the aforementioned object, an illuminating and optical apparatus for inspecting soldering of PCB of the present invention comprises: a fixed member which forms a horizontal plane at the top thereof and a tilted plane at the side thereof; first illuminating means disposed at the upper plane of the fixed member for illuminating the inspecting part attached on the PCB ; second illuminating means disposed at the tilted plane of the fixed member for illuminating the inspecting part to obtain an image whose shade is inverted to that obtained by the first illuminating means; control means for controlling brightness of the first and second illuminating means and turning on off of power; and optical means disposed at the upper portion of the fixed member for photographing at large and small views the inspecting part illuminated by the first and second illuminating means under the control of the control means. On the position of the PCB. the trace of the intersection of the light incident from the first illuminating means may be larger in its diameter than that of the light of incident from the second illuminating means, or the contrary. The first illuminating means has a plurality of lamps arranged in a plurality of ring-shaped fixtures of different diameters therebetween but an identical height thereto, being installed close to a photographing hole of the optical means formed on the fixed member; and the second illuminating means has a plurality of lamps arranged in a plurality of ring-shaped fixtures of different diameters and heights therebetween, a plurality of lamps of ring- shaped fixtures located at the lowest end thereof being disposed close to the lower portion of the tilted plane of the fixed member and a plurality of lamps of ring-shaped fixtures located at the highest end thereof being positioned at an angle of at least 30 degrees between a straight line formed by a plurality of the ring-shaped fixtures of lamps arranged at the outermost portion of the first illuminating means connecting the center of the inspecting part positioned at the standard height and another straight line formed by a plurality of ring-shaped fixtures of lamps arranged at the uppermost portion of the second illuminating means connecting the center of the inspecting part positioned at the standard height. Furthermore, the control means comprises: a power switch; a lightness control unit for varying 256 levels of the resistance value by turning around a plurality of lightness switches; and. in case of turning on the power switch, and an output unit which outputs electric current in accordance with the resistance value of the lightness control unit and applies it to the first and second illuminating means. The optical means comprises: reflected light transmitting means which halves and outputs the light reflected by the inspecting part; large and small view cameras which respectively photographs the reflected light halved by the reflected light transmitting means, and large and small view lenses respectively assembled in front of the large and small view cameras for accordingly controlling the size of the views to be photographed by the large and small view cameras, wherein the reflected light transmitting means includes a half mirror of a triangular prism which enables a half of the light reflected by the inspecting part to transmit to its proceeding direction and the other half of it to further reflect to an angle of 90 degree, a large view total reflection mirror of a planar mirror which reflects identically to an axis of the large view camera the latter half of the light reflected by the half mirror at the angle of 90 degrees; a first total reflection mirror of the small view of a triangular prism which reflects the first half of the reflected light transmitted at the half mirror; a second total reflection mirror of the small view of a planar prism which reflects identically to an axis of the small view the light reflected by the first total reflection mirror of the small view; and large and small view lenses which draws the light reflected by the total reflection mirror of the large view and the second total reflection mirror of the small view into the large and small view cameras. 10 Brief Description of Drawings FIG. 1 is a schematic view for illustrating an embodiment of the structure and operational state of a conventional illuminating and optical apparatus; FIG. 2 is a schematic view for illustrating another embodiment of the structure 15 and operational state of a conventional illuminating and optical apparatus; FIG. 3 is a cross-sectional view for illustrating the structure of an illuminating and optical apparatus in accordance with the present invention; FIG. 4 illustrates a position to install the second illuminating means of the illuminating and optical apparatus in accordance with the present invention; 20 FIG. 5 illustrates distribution of emitted light on the polar coordinates provided that a lamp is a light emitting source of the illuminating and optical apparatus in accordance with the present invention; FIG. 6 illustrates angles of incident light drawn into the first and second illuminating means of the illuminating and optical apparatus in accordance with the " > present invention: FIG. 7 illustrates the structure of control means which controls turning on/off and brightness of the first and second illuminating means of the illuminating and optical apparatus in accordance with the present invention; FIGs. 8 and 9 illustrate pictures of image signals photographed in accordance with illumination of the first and second illuminating means of the illuminating and optical apparatus in accordance with the present invention; and FIG. 10 illustrates the traces of the focuses of the first and second illuminating means. Best Mode for Carrying out the Invention The illuminating and optical apparatus for inspecting the soldered state on the PCB of the present invention will be described in detail with reference to the accompanying drawings, FIGs. 3 through 9. FIG. 3 is a cross-sectional view for illustrating the structure and operational state of an illuminating and optical apparatus of the present invention. At this time, reference numeral 30 denotes a fixed member whose top portion is formed in a horizontal plane and lateral portion is formed in a tilted plane of an approximately circular cone. First illuminating means 31 is assembled at a horizontally leveled position inside the upper portion of the fixed member 30 and second illuminating means 32 at an inner circumference of a position where a circular cone is formed. At the center of the top plane of a fixed member 30. there are a photograph hole 30a formed to enable optical means 40 to photograph an inspecting part 34 fixed on a PCB 33, first illuminating means 31 disposed at the external side of the photograph hole 30a and second illuminating means 32 disposed at the internal side of the tilted plane which forms the circular cone of the fixed member 30. wherein the first and second illuminating means 31. 32 are selectively turned on/off by control means. which will be described below, to illuminate the inspecting part 34 and control the brightness of the illuminating light. The first illuminating means 31 is a plurality of lamps formed in concentric circles on the same planar level and shaped in a plurality of ring-shaped fixtures having different diameters, for example, two rows of ring-shaped fixtures, being installed close to the external side of the photograph hole 30a. The second illuminating means 32 is a plurality of lamps formed in concentric circles and shaped in a plurality of ring-shaped fixtures having different diameters and heights, for example. 3 rows of ring-shaped fixtures to obtain an image, whose shade is inverted to that obtained by the first illuminating means 31, at the metal surfaces having the reflection characteristic of a mirror such as the soldered surface of the inspecting part 34, an electrode surface and the like. The ring-shaped lamps 32a disposed at the lowest end of the second illuminating means 32 are positioned close to the lower portion of the tilted plane formed in a circular cone of the fixed member 30. A ring of a plurality of lamps 32b disposed at the highest end of the second illuminating means 32. as shown in FIG. 4, are located exactly at an angle ( 1) of more than 30 degrees between a straight line formed by a plurality of the ring shaped lamps 31a arranged at the outermost of the first illuminating means 31 connecting the center of the inspecting part 34 positioned at the standard height (h) and another straight line formed by a plurality of the ring shaped lamps 32b connecting the center of the inspecting part 34 positioned at the standard height (h). Light emitting diodes are, for example, used for a plurality of the first and second illumination lamps 31, 32. At this time, the first illuminating means 31 are arranged in two rows of ring- shaped fixtures and the second illuminating means 32 are arranged in three rows of ring-shaped fixtures, both of which are described as an example. Therefore, the first and second illuminating means 31. 32 can be arranged in a plurality of ring-shaped fixtures, more than two and three rows of ring-shaped fixtures. Reference numeral 40 denotes optical means fixed over the fixed member 30 to photograph the inspecting part 34. The optical means 40 includes large and small view cameras 41. 42 to respectively obtain different view sizes of images in accordance with the sizes of the part 34, wherein the large and small view cameras 41. 42 respectively include large and small view lenses 41a. 42a (or a small magnitude lens 41a and large magnitude lens 42a) to collect the reflected light drawn through reflected light transmitting means 43 which will be described below. The reflected light transmitting means 43 includes a half mirror 431 which transmits a half of the light reflected by the inspecting part 34 to continuously advance to its proceeding direction and reflects the other half of the light to change its proceeding direction to an angle of 90 degrees, a total reflection mirror 432 of the large view which reflects again the light reflected by the half mirror 431 at the angle of 90 degrees to identically proceed to the axis of the large view camera 41 and the large view lens 41a, a first total reflection mirror 433 of the small view which changes the proceeding direction of the light transmitted through the half mirror 431 at the angle of 90 degrees and a second total reflection mirror 434 of the small view which reflects again the light, whose proceeding direction was changed at 90 degrees by the first total reflection mirror 433 of the small view, to identically advance to the axis of the small view camera 42 and the small view lens 42a. For example, the half mirror 431 and the first total reflection light mirror 433 of the small view are made of triangular prisms, and the total reflection mirror 432 of the large view and the second total reflection mirror 434 of the small view are made of planar mirrors. The illuminating and optical apparatus of the present invention thus constructed completely collects the light emitted by a plurality of lamps arranged in a plurality of rows of the first and second illuminating means 31 , 32 on the view axis 40a of the large and small λ'iews 41. 42. wherein the lamps should be arranged around the view axis of the large and small view cameras 41 and 42 at an angle to draw sufficient light from the light emitting model of the lamps and the reflection model of the inspecting part 34 to the large and small view cameras 41. 42, depending on the positions of the lamps and at the same time to maximize the uniformity of brightness within the range of the view. FIG. 5 illustrates the distribution of emitted light at polar coordinates, provided that a lamp is a light emitting source of the illuminating and optical apparatus in accordance with the present invention.. In FIG. 5, the amount of light emitted by the lamps, centering the light axis of the lamps, can be explained by a shape of the Gaussian distribution in a mathematical formula as follows: Mathematical formula 1 9 Φ K l ) = exp 2 K a L a where η is a radian between the optical axis of a lamp- and a predetermined light ray, I ( η ) the intensity of the light of the lamp at the angle η relative to the optical axis of the lamp, Φ a power constant of the light emitted by the lamp and a a light dispersion angle of the lamp. In FIG. 5, if a lamp illuminates a predetermined surface at the distance of 1, the amount of the light E to be reflected along the view axis of the camera at a predetermined point P(x.y) of the surface is as follows: Mathematical formula 2 E = I( r, ) -2^1 [W/m 2 where ψ is an angle between a light ray and the view axis of the camera. In addition, the total amount of the light emitted by a plurality of N lamps, drawn and reflected at a point P (x, y) can be estimated by adding the amount of light reflected by each lamp in mathematical formula 3 as follows: Mathematical formula 3 E(x , y) = J. o £_ y) [ /fτr] The angle of the optical axis of a lamp tilted from the view axis 40a of the large and small view cameras 41, 42 is determined when lamps are arranged to maximize the amount of reflecting light within view and, at the same time, to maximize the uniformity of reflecting light within the range of the view in the following mathematical formula 4: Mathematical formula 4 C - a ■ Σ E(x, y) ÷ β • Q where a and. β are weight values, E the total quantity of light accumulated within the range of the view, and Q the uniformity, that is, an inverse value of the brightness distribution within the range of the view. FIG. 6 illustrates angles of incident light drawn into the first and second illuminating means which are arranged as described above. As shown in FIG. 6, the trace 31c of the intersection of the incident light drawn by the first illuminating means 31 to meet with the PCB 33 are respectively shaped hi a circle, and the trace 32c of the intersection of the incident light of the second illuminating means 32 to meet with the PCB 33 is shaped in a circle as well. The traces 31c and 32c are different in its diameter each other. In addition, the second illuminating means 32 is arranged in a plurality of rows of ring-shaped fixtures to widen the angle of the light of the lower ring-shaped fixtures of lamps, thereby minimizing the light interference caused by other neighboring parts. Under the aforementioned illumination, the reflected light radiated from the inspecting part 34 is divided into two by the half mirror 431 of the reflected light transmitting means 43. The first half of the reflected light divided into half is photographed by the large view camera 41 through the total reflection mirror 432 of the large view and the large view lens 41a. On the other hand, the other half of the reflected light is photographed by the small view camera 42 through the first and second total reflection mirror 433, 434 of the small view and the small view lens 42a. FIG. 7 illustrates the structure of the control means which turns on/off the first and second illuminating means 31, 32 and controls the brightness of the illuminating and optical apparatus in accordance with the present invention. As described above, resistors Rl - R8 are respectively connected in series between one side of fixed elements al - a8 and the other side of fixed elements bl - b8 of a plurality of lightness switches LSW1 - LSW8, and a connecting point of the one side of the fixed elements al - a7 and the resistors Rl - R7 of a plurality of lightness switches LSW1 - LSW7 are respectively connected with operating elements of a plurality of lightness switches LSW2 - LSW8, thereby forming a lightness control unit 50. The operating elements of the lightness switch LSW1 are connected to grounding by way of a power switch PSW. The connecting point of the one side of the fixed element a8 and the resistor R8 of the lightness switch LSW8 is connected through the resistor R9 to the resistor R10 and the base of the transistor (Q). so that a collector of the transistor (Q) is connected through the resistor Rl 1 to the first illuminating means 31. thereby forming an output unit 51. All of the resistors Rl - R8 are set up at different resistance values as follows: Rl = 2R2= 4R3 = 8R4=16R5 = 32R6 = 64R7 = 128R. The control means, which controls the turning-on/off and brightness of the second illuminating means 32, is constructed in the same structure as the one which controls the turning-on/off and brightness of the first illuminating means 31. The control means of the present invention thus constructed, in case the power switch PSW is connected to turn on power and the operating elements of the lightness switches LSW1 - LSW8 are connected to the one side of fixed elements al - a8, the voltage applied to the base of the transistor (Q) is low to increase the voltage difference between the emitter and the base of the transistor (Q), so that a great deal of electric current flows to the collector of the transistor (Q) to turn on the lamps of the first and second illuminating means 31, 32 very brightly to illuminate the inspecting part 34.. Furthermore, in case that the operating elements of the lightness switches LSW1 - LSW8 are connected to the other side of fixed elements bl - b8, the voltage applied to the base of the transistor (Q) is high enough to decrease in the voltage difference between the emitter and the base of the transistor (Q), so that only a little electric current flows to the collector of the transistor (Q) to turn on the lamps of the first and second illuminating means 31, 32 less brightly to illuminate the inspecting part 34. At this time, the resistance value of resistors Rl - R8 is differently set up as follows: Rl = 2R2 = 4R3 = 8R4 = 16R5 = 32R6 = 64R7 = 128R8. As operating elements of the lightness switches LSW1 - LSW8 are selectively turned around, the lamps of the first and second illuminating means 31. 32 can be controlled at 256 levels of brightness to illuminate the inspecting part 34. When the inspecting part 34 is inspected with the illuminating and optical apparatus of the present invention, the first illuminating means 31 is turned on at first to illuminate the part 34 with the second illuminating means 32 being turned off. At this time, the part 34 is photographed by the large and small view cameras 41. 42 to obtain the first image thereof. Then, the second illuminating means 32 is turned on to illuminate the part 34 with the first illuminating means 31 being turned off. At this time, the part 34 is photographed by the large and small view cameras 41, 42 to obtain the second image thereof. The two images obtained as such, that is, two images, whose shade is inverted to the soldered unit and the electrode unit made of a metal surface of the inspecting part 34, are used for determining the mounted and soldered states thereof. In other words, as shown in FIG. 8, if the first illuminating means 31 is turned on to illuminate the inspecting part 34 with the second illuminating means 32 being turned off, a soldering fillet part formed at the tilted plane is shown as a negative area (dark area) due to a characteristic of light reflection while the ends of an electrode and a pad made in the horizontal plane are shown as a positive area (bright area). As shown in FIG. 9, if the second illuminating means 32 is turned on to illuminate the inspecting part 34 with the first illuminating means 31 being turned off, the shade has been inverted, exactly opposite to the case shown in FIG. 7. Therefore, the soldering fillet part formed at the tilted plane is shown as the positive area while the ends of the electrode and the pad formed at the horizontal plane are shown as the negative area. With the aforementioned two images obtained as such, the areas already designated for inspection are used for determining the mounted and soldered states of the inspecting part 34. For example, the two images can be separately used, or an image created by subtracting or adding the other image from or to one image can be also used for inspecting the mounted and soldered states of the inspecting part 34. Industrial Application As described above, there are advantages of the illuminating and optical apparatus of the present invention in that the apparatus can selectively control horizontal or vertical illumination, consistently set an illuminating brightness in a digital method and properly arrange the focus of incident light of the light emitting means larger than the view to improve the uniformity of illuminating brightness and to increase the inspecting speed and reliability by efficiently corresponding to the size of various parts. In addition, there is advantages of the illuminating and optical apparatus in that the apparatus can maximize the quantity of light which is reflected from the inspecting part and incident into the camera, and at the same time the illuminating angle of the illuminating means can be properly controlled to thereby keep the distribution of the quantity of light even at its maximum.

Claims: WHAT IS CLAIMED IS: 1. An illuminating and optical apparatus for inspecting soldering of PCB. comprises: a fixed member which forms a horizontal plane at the top thereof and a tilted plane at the side thereof; first illuminating means disposed at the upper plane of the fixed member for illuminating the inspecting part attached on the PCB ; second illuminating means disposed at the tilted plane of the fixed member for illuminating the inspecting part to obtain an image whose shade is inverted to that obtained by the first illuminating means; control means for controlling the brightness of the first and second illuminating means and turning on/off of power; and optical means disposed at the upper portion of the fixed member for photographing at large and small views the inspecting part illuminated by the first and second illuminating means under the control of the control means. 2. The apparatus, as defined in claim 1, wherein the first illuminating means has a plurality of lamps arranged in a plurality of ring-shaped fixtures of different diameters therebetween but an identical height thereto, being installed close to a photographing hole of the optical means formed on the fixed member. 3. The apparatus, as defined in claim 1 , wherein the second illuminating means has a plurality of lamps arranged in a plurality of ring-shaped fixtures of different diameters and heights therebetween. 4. The apparatus, as defined in claim 3. wherein a plurality of lamps of ring-shaped fixtures located at the lowest end of the second illuminating means are disposed close to the lower portion of the tilted plane of the fixed member. 5. The apparatus, as defined in claim 3, wherein a plurality of lamps of ring-shaped fixtures located at the highest end of the second illuminating means are located at an angle of at least 30 degrees between a straight line formed by a plurality of ring-shaped fixtures of lamps arranged at the outermost portion of the first illuminating means connecting the center of the inspecting part positioned at the standard height and another straight line formed by a plurality of ring-shaped fixtures of lamps arranged at the uppermost portion of the second illuminating means connecting the center of the inspecting part positioned at the standard height. 6. The apparatus, as defined in claim 1, wherein the traces of the intersection of the incident light drawn by the first and second illuminating means to meet with the PCB are respectively shaped in circles, the traces being different in its diameter each other. 7. The apparatus, as defined in claim 6, wherein the first illuminating means has a plurality of lamps arranged in a plurality of ring-shaped fixtures of different diameters therebetween but an identical height thereto, being installed close to a photographing hole of the optical means formed on the fixed member. 8. The apparatus, as defined in claim 6, wherein the second illuminating means has a plurality of lamps arranged in a plurality of ring-shaped fixtures of different diameters and heights therebetween. 9. The apparatus, as defined in claim 8. wherein a plurality of lamps of ring-shaped fixtures located at the lowest end of the second illuminating means are disposed close to the lower portion of the tilted plane of the fixed member. 10. The apparatus, as defined in claim 8. wherein a plurality of lamps of ring-shaped fixtures located at the highest end of the second illuminating means are located at an angle of at least more than 30 degrees between a straight line formed by a plurality of ring-shaped fixtures of lamps arranged at the outermost portion of the first illuminating means connecting the center of the inspecting part positioned at the standard height and another straight line formed by a plurality of ring-shaped fixtures of lamps arranged at the uppermost portion of the second illuminating means connecting the center of the inspecting part positioned at the standard height. 1 1. The apparatus, as defined in claim 1, wherein the control means comprises: a power switch; a lightness control unit for varying resistance value by turning around a plurality of lightness switches; and an output unit, in case of turning on the power switch, for outputting electric current in accordance with the resistance value of the lightness control unit and applying it to the first and second illuminating means. 12. The apparatus, as defined in claim 11. wherein the lightness control unit varies 256 levels of resistance value by turning around a plurality of lightness switches. 13. The apparatus, as defined in claim 1, wherein the optical means comprises: reflected light transmitting means which halves and outputs the light reflected by the inspecting part: large and small view cameras which respectively photograph the reflected light halved by the reflected light transmitting means: and large and small view lenses respectively assembled in front of the large and small view cameras for accordingly controlling the size of the views to be photographed by the large and small view cameras. 15. The apparatus, as defined in claim 14. wherein the half mirror and the first total reflection mirror of the small view are made of triangular prism, and the total reflection mirror of the large view and the second total reflection mirror of the small view are made of planar mirror. 16. The apparatus as defined in claim 1 further comprises optical axis control means for determining the optical axis of the first and second illuminating means to maximize the quantity of light which is reflected from the inspecting part and incident into the camera and to maximize the uniformity of reflecting light within the range of the view, the optical axis control means operated in accordance with mathematical formulas 1 , 2 and 4.

Inventors: KIM JAE SEON, KIM, JAE, SEON
Applicants: KIM JAE SEON, SAMSUNG ELECTRONICS CO LTD, KIM, JAE, SEON, SAMSUNG ELECTRONICS CO., LTD.
Application year: 1999
Main classification: G01N21
IPC codes: G01N21, H05B37, H05K13