JP3048758B2 - Device for positioning electronic elements in circuit supports - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for positioning an electronic element on a circuit carrier having a circuit pattern.

[0002]

2. Description of the Related Art DE-A-242 320 discloses a technique for mounting on a conductor substrate in which the conductor substrate is held on a lever arm under vacuum by means of a holder using a holder. Devices for accurately positioning the pole elements are known. The mounting positions on the lower surface of the element and the surface of the conductive substrate are illuminated by a light source. Further, a semi-transparent mirror is provided so that a real image of the mounting position on the surface of the conductive substrate and a virtual image of the lower surface of the element can be observed through the semi-transparent mirror. Due to the lateral shift of the cross table, the image of the mounting position on the surface of the printed circuit board is moved with respect to the image of the underside of the element until the corresponding reference points of the two images coincide. The lever arm is then pivoted in the direction of the conductor board by 90 ° without any change in the optical system until the lower surface of the element is correctly positioned in the mounting position on the surface of the conductor board. After the element is released from the lever arm, the lever arm is pivoted back to its original position without the element.

[0003] Despite the fact that this device basically operates satisfactorily, the realization of the necessary fixed spatial correspondence between the optical system having a semi-transparent mirror and the swivel arm is very complicated in structure. In addition, it has been found that the positioning is not always always accurate, despite the adjustment of the two images in the proper positional relationship after the rotation of the lever arm.

[0004]

The object of the present invention is to provide a device for positioning an element in a circuit carrier according to the preamble of claim 1 with an optical system having a semi-transparent mirror over a long time interval in a simple structure of the device. It is an improvement so that a fixed correspondence with the pivot arm with the element holder is ensured and accurate positioning is possible.

[0005]

This object is achieved according to the invention by the features of claim 1.

The support arm and the pivot arm for the translucent border form one structural unit in which the pivot axis of the pivot arm is supported by the support arm, so that even after prolonged use of the device the image of the element and the pivot arm are maintained. Simple structures can be used to ensure the correct positioning of the elements on the pattern of the circuit support, with correspondingly precise adjustments to the image coincidence (overlap) of the corresponding places of the circuit support. .

[0007] Advantageous embodiments and refinements are possible with the further claims.

Advantageously for the two-handed operation of the swivel arm,
A cut or chamfer or a cutout is provided in a portion of the support arm that protrudes above the circuit support.

Furthermore, it is advantageous to illuminate the element and the circuit support with light of different colors in order to distinguish between the image of the element and the image of the circuit support and to more easily adjust the coincidence of the images. Also, the element or circuit support can be illuminated in a flashing manner at the starting position of the pivot arm, so that better identification of pins and pads is realized, especially in the case of monochrome video technology.

By allowing the light source illuminating the element to be shut off after positioning, the positioning of the circuit support can be monitored with satisfactory contrast using an optical system. Further, the work place can be additionally used as an inspection place.

It is particularly advantageous to arrange the two mirrors obliquely at a shallow (gentle) angle between them in the observation beam path in front of the semi-transparent mirror. In this way, for example, in a large element, points that are far apart from each other can be greatly enlarged and observed and can be made to coincide with each other, so that the positioning accuracy is improved.

According to an advantageous embodiment, the pivot arm is simultaneously designed as a brazing device, so that the positioning and brazing operations can be carried out in one working step. By providing the pivot arm with guide rails, the various brazing heads or brazing nozzles or element holders present on the plate-shaped support element can be replaced by simple removal and insertion. When the plug-in and connecting elements are arranged in the direction of the guide rail during the plug-in, the necessary electrical connections or corresponding further connections can be made.

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a perspective view of an apparatus 1 for positioning an element on a circuit support. This device comprises, as essential components, a support arm 2 for receiving an optical system 3, a pivot arm 4 with an element holder 5, a circuit support 7
Is formed by an air bearing table 6 for receiving the air. The support arm 2 and the swivel arm 4 are structurally integrated and are fixedly mounted on an assembly mounting plate 8.

As can be seen from FIGS. 2 and 3, the support arm 2 comprises a first part 9 arranged vertically, a second part 1 extending obliquely forward and projecting above the circuit support 7.
0, as well as a third part 1 with a receiving plate 12 which is also vertically connected to this second part and protrudes on one side.
1. The third part is provided with an optical system 3 comprising a microscope 13 and a cube-shaped beam splitter 14 in this embodiment. The cube-shaped beam splitter 14 is a semi-transparent mirror disposed as a constituent member at an angle of 45 °. 15

As will be explained in more detail later, the pivot arm 4 is simultaneously designed as a brazing device and comprises a vertically provided element 16 and a bearing 17 for a pivot 18. The support arm 2 and the pivot arm 4 are arranged closely adjacent to each other, wherein the pivot 18 is mounted on the first part 9 of the support arm 2. Swivel axis 1
The other part of 8 is supported on a side part 19, which, like the first part 9 of the support arm 2,
It is mounted on a mounting plate 20. Further, the mounting plate 20 is fixedly connected to the assembly mounting plate 8.

An element holder 5 is provided at a free end above the pivot 4 and operates by negative pressure. That is, element 2
When a negative pressure is applied through the negative pressure duct 22 indicated by the broken line, the surface of the element 1 is sucked, so that the lower surface of the element 21 can be observed. The swivel axis is simultaneously configured as a brazing device mechanism, and in the embodiment according to FIG. 2 a beam crimping brazing method is used. For this purpose, at the free end of the swivel arm 4 a beam crimping part brazing head having a beam crimping part 23 is provided, in which case a current conductor and a high current terminal are provided on the swivel arm 4.

As shown by a chain line in FIG. 2, between the pivot axis of the pivot arm and the lower surface of the element 21, between the central portion of the element and the central portion of the semi-transparent mirror 15, and further,
5 between the central portion of the circuit support 7 and the central portion of the circuit pattern 24 on which the element 21 can be disposed, as well as the line connecting the pivot 18 and the surface of the circuit support 7 to form a square. It is formed. In this way, it is ensured that the element is correctly positioned. The air bearing table 6 has a receiving member 26, in which the lower surface of the plane on which the circuit support is held or fixedly fastened between the surfaces is the circuit support 7 Are obliquely configured so that their respective surfaces 25 are always at the same height with respect to the pivot axis 18 of the pivot arm, even at different thicknesses.

For better observation, two light sources 27 are provided, one of which is the element holder 5.
Illuminates the element 21 at the other end and illuminates the circuit support 7 on the other hand. In FIGS. 2 and 3, the observer's eye is indicated by reference numeral 28, and reference numeral 29 represents various observation means such as a loupe, a microscope, a camera, and the like.

In order to be able to operate the swivel arm 4 or the element holder with the left hand, a cutout or notch 30 is provided in the central portion 10 of the support arm 2, so that the operator can use the support arm 2. Can be treated well beyond.

The operation is as follows. After the element 21 is placed on the element holder with its lower surface facing forward, the operator observes the image of the element 21 and the circuit pattern on the circuit support through the partially translucent mirror 15. The fine adjustment member 13 is moved so that the image of the element 21 and the image of the circuit pattern 24 overlap. Thereafter, the swivel arm 4 is swiveled downward by passing through the cube beam splitter 14 so that the pins of the element 21 are located on the pads of the circuit pattern 24. Next, the brazing device is operated, and the solder existing on the circuit pattern 24 is heated by the beam crimping portion 23. As a result, fixed bonding between the element 21 and the circuit pattern 24 can be formed.

In the case of a large element which is frequently used recently, the observation field may be too small even if it is enlarged to a required size. In other words, even when the images are superimposed in the observation field, the points of the elements located at a considerable distance from the image to be observed do not overlap with the points of the pattern associated with the elements. In order to eliminate this drawback, according to FIG. 4 shown on the incident side of the observation beam, two mirrors 32, 33 are arranged in front of the cube beam splitter 14 with the semi-transparent mirror 15. They are positioned oblique to the cube beam splitter and are slightly redirected toward each other so that a shallow (gentle) angle is formed between the mirrors. As a result, the beam entry side 36 of the element and the beam entry side 37 of the circuit support are spread apart, i.e., two images are located next to each other that need to be moved to overlap. As indicated by arrows 38, 39, these mirrors are adjustable in position, i.e., the diagonal position with respect to cube beam splitter 14 and the position between them can be adjusted. . Therefore, it is possible to set and adjust the desired position of the element or the circuit support to be observed. In this case, the optical system has a camera, which reproduces two partial images on a monitor.

The same function can be achieved when two cameras are used as the optical system. These cameras are aimed at a cube beam splitter with a semi-reflective mirror at an angle to the optical axis, which can be set differently, and are connected to one or two screens.

As still another configuration, only one camera is provided, and two prisms are set on the observation beam incident side. These prisms divide the beam incident side of the element and the beam incident side of the circuit support, respectively. In this case, these prisms are for example cylindrical and have at least one inclined end face. In this case, the position of the element or the circuit support to be observed can be adjusted by turning the prism about the optical axis. It is also possible to provide two prisms respectively arranged before and after each other. In this case, by turning the prisms arranged before and after each other,
Adjustments are performed relative to each other. Thus, the displacement angle and the displacement direction can be set and adjusted. Advantageously, 1
These prisms in the set of prism pairs each have one end face with the same gradient. In the case of a solution using such a prism, it is necessary to use monochromatic light in order to avoid defocusing due to a color boundary. This solution has the advantage that both partial images are reproduced at the correct angle, as compared to mirrors which are turned to face each other according to FIG.

In the case of the embodiment using two mirrors according to FIG. 4, for capturing and detecting a plurality of objects of different sizes and separated from one another, the mirrors are at right angles to the optical axis of the observation device. Adjusting the mirrors 32, 33 about the axes 40, 41 located in the plane eliminates the disadvantages of distorted lines in the optical system. The camera 44 and the mirror holder 42 are pivoted as a unit to additionally adjust the area to be observed. For example, if the camera and mirror holder are pivoted about one of a number of axes, then it is advantageous to have the partially translucent mirror substantially at a 45 ° angle, for example, as axis 43 in FIG. By pivoting about one axis passing through the center, two diagonals of the element and the circuit support can be brought into the image area.

FIG. 6 shows the upper part of the pivot arm in a more accurate manner. In this case, the element holder 5 is arranged on the support plate 35 together with the element 21 and the beam crimping portion 23 of the brazing head. The support plate is guided in lateral guide rails 34 which extend vertically in the initial position of the pivot arm 4. In this case, the support plate 35 can be easily replaced by simple withdrawal and insertion into the guide rail 34. More precisely, the rails 34 are provided for guiding the respective support plates 35 with different brazing heads or different element holders in one straight line. This straight line lies in one plane, to which the pivot axis 18 and the longitudinal axis of the pivot arm 4 are parallel. In this way, different brazing heads can be provided, depending on the different sizes of the elements.

In this embodiment, the brazing apparatus is shown as a beam crimping part brazing head, but a brazing head for heat welding or a gas nozzle for high-temperature gas brazing may be provided in the swivel arm 4. it can. in this case,
The pivot arm 4 has in each case an additional device, such as a heating cartridge or possibly a power transformer for the current supply of the brazing head. For example, element 2
1 for holding a vacuum, correspondingly for cooling air, for hot gas flow during heating gas brazing, high current plug for electrically heated brazing heads If the connecting parts and the like are also arranged in the direction of the guide rail 34, when the brazing head or the gas nozzle is replaced, that is, when the support plate 35 is replaced, a simple pull-out and insertion of a new head can be performed. The guide rail 34 makes it possible to connect all means. Furthermore, a control device (not shown) is provided, which controls, for example, the element holder and the brazing device. For example, an encoding device is provided for each brazing head on the support member 35 in order to enable the control device to receive information about which brazing head is currently installed in the swivel arm 4. This coding device also supplies via a corresponding plug connection information to the control device which brazing head or gas nozzle is present in the swivel arm. In this way, the control device can supply the required brazing energy depending on the size of the brazing head.

In order to prevent the swing arm 4 from being distorted due to thermal fluctuations during brazing, the swing arm is advantageously constituted by a carbon fiber layer having a strong fiber component in the longitudinal direction of the arm. ing. This type of carbon fiber layer has a small coefficient of thermal expansion suitable for the mounting speed and a small mass suitable for the mounting speed.

Two different light sources 27 are provided for illuminating the element 21 and the circuit support 7. These light sources advantageously have different colors of light,
This makes it possible to better distinguish images that need to be moved to overlap. After positioning or positioning, and possibly after brazing,
The light source that illuminates the element in its initial position is shut off,
The characteristics obtained on the circuit support can be controlled and adjusted with good contrast using the optical system 3.

In an alternative embodiment of the illumination, the light source can be turned on and off, so that, for example, in monochromatic video technology as well, both images can be better distinguished.

In yet another arrangement, the element and circuit support are alternately illuminated in an initial position, and an optional electronic image recognition and processing device is operated in synchronization with the frequency at which the illumination is alternated. Can be done.

[Brief description of the drawings]

FIG. 1 is a perspective view of an apparatus according to the present invention.

FIG. 2 is a side view of the device according to the invention.

FIG. 3 is a front view of the device according to the present invention.

FIG. 4 is a basic configuration diagram showing a semi-transparent mirror in a cube beam splitter together with two mirrors arranged obliquely forward.

FIG. 5 is a basic configuration diagram showing a semi-transparent mirror in a cube beam splitter together with two mirrors arranged obliquely forward.

FIG. 6 is a view showing a swing arm including a replaceable brazing head and an element holder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positioning device 2 Support arm 3 Optical system 4 Revolving arm 5 Element holder 6 Air bearing table 7 Circuit support 8 Assembly mounting plate 12 Housing plate 13 Microscope 14 Cube beam splitter 15 Semi-transmissive mirror 17 Supporting part 18 Revolving axis 19 Lateral Part 20 Mounting plate 21 Element 22 Negative pressure duct 23 Beam crimping part 24 Circuit pattern 26 Receiving member 27 Light source 30 Depression 31 Fine adjustment member 32, 33 Mirror 34 Guide rail 35 Support plate 42 Mirror holder 44 Camera

Claims (23)

(57) [Claims] 1. A device for positioning an electronic element on a circuit support having a circuit pattern, which is arranged so as to be shiftable in one plane, and for accommodating an optical system having a semi-transparent boundary. A support arm and a pivot arm holding the element at a free end, wherein the semi-transparent mirror is capable of detecting the element and the circuit support held by the pivot arm by the semi-transparent boundary. And the circuit support is shifted such that the image of the element corresponds to a pattern on the circuit support corresponding to the element and the pivot arm is pivoted from its starting position. And wherein the element is mounted on a pattern corresponding to the element, wherein the support arm (2) and the pivot arm (4) for the semi-transparent mirror (15) are one structural unit. Tsu preparative was formed and the pivot axis of the pivot arm (4) (18) is a positioning device of an electronic device in the circuit substrate, characterized in that it is supported on the support arm (2). 2. The support arm (2) comprises a pivot arm (4).
A vertically arranged first part (9) for accommodating the bearing part of the swivel shaft (18) and a second, preferably oblique, projecting forwardly above the circuit support (7). Part (10)
The device for positioning an electronic element in a circuit support according to claim 1, further comprising a vertically disposed third portion (11) supporting the optical system (3). 3. The second part (10) of the support arm (2).
3. The electronic component in a circuit carrier according to claim 1, wherein the device has a recess (30) or a cut-out on the side opposite the pivot arm (4) for a better handling operation of the pivot arm. Positioning device. 4. An illuminating device (2) having at least one light source for illuminating a circuit support (7) and an element (21).
7. The method according to claim 1, further comprising the step of:
Item 10. A device for positioning an electronic element in a circuit support according to Item 7. 5. The lighting device comprises a circuit support and an element (2).
5. The device according to claim 4, wherein 1) is illuminated by light of different colors. 6. The device according to claim 4, wherein at the starting position of the pivot arm, the circuit carrier and / or the element are illuminated in a flashing manner. . 7. The device according to claim 4, wherein the light source for illuminating the element is cut off. 8. A device according to claim 1, wherein the semi-transparent mirror is a component of a cubic splitting device (cube beam splitter). 9. An observation beam path in front of a semi-transparent mirror (15),
9. The mirror according to claim 1, wherein two mirrors angled with respect to one another are arranged in such a way that the observation beam path is widened.
The device for positioning an electronic element in a circuit support according to any one of the preceding claims. 10. The electronic device according to claim 9, wherein the positional relationship between the two mirrors (32, 33) and the relative positional relationship with respect to the semi-transparent mirror (15) are variable. Positioning device. 11. The pivoting arm (4) is provided with a brazing device mechanism for brazing the element (21) to the pattern (24) when pivoted downward. 2. A device for positioning an electronic element in a circuit support according to claim 1. 12. The brazing device according to claim 11, wherein the brazing device is formed as a heated gas brazing device having a gas nozzle, wherein the swivel arm (4) comprises a heating cartridge for air or inert gas. A device for positioning electronic elements on a circuit support. 13. The brazing device may be a beam crimp type brazing device (Strahlungsbuegelloetvorrichtung) or a hot-melt type or thermoden brazing device (Thermodenloetv).
12. The device according to claim 11, wherein the pivot arm includes a current lead for a brazing head arranged on the pivot arm. 14. The element carrier (5) of the pivoting arm (4) and, if appropriate, the brazing head or gas nozzle of the brazing device are interchangeable, wherein the pivoting arm is a lateral guide rail (34). Has,
A plate-like support member (3) for accommodating the brazing head or gas nozzle and the element holder (5) is provided on the guide rail.
14. The device according to claim 1, wherein 5) is pluggable and connectable. 15. A swing arm (4) and a support member (3).
5) A plug-in and coupling element is provided which forms the connection required for powering the brazing head or air nozzle and the element carrier during plug-in connection of the support member to the guide rail (34). 15. The device for positioning an electronic element in a circuit support according to claim 14, wherein: 16. A controller is provided for controlling the brazing process and for providing the required brazing energy.
In this case, information about which brazing head or gas nozzle is present on the swivel arm from the coding unit belonging to the brazing head or gas nozzle corresponding to the brazing head or gas nozzle mounted on the support member is sent to the control device. 16. The device for positioning an electronic element in a circuit support according to claim 11, which is supplied. 17. The device according to claim 1, wherein the swiveling arm comprises a carbon fiber laminate having a high fiber content in the longitudinal direction of the arm. . 18. The optical system according to claim 1, wherein the optical system comprises two cameras oriented in the semi-transparent mirror at two differently variable and adjustable angles with respect to the optical axis. 2. A device for positioning an electronic element in a circuit support according to claim 1. 19. The circuit according to claim 1, wherein two prisms rotatable about the optical axis are provided for splitting the beam path in front of the semi-transparent mirror. A device for positioning electronic elements on a support. 20. The apparatus according to claim 19, wherein each of the two prisms comprises two prisms that are rotatable with respect to each other. 21. The apparatus according to claim 1, wherein the optical system has one camera. 22. The two mirrors (32, 33) are moved and adjusted about an axis (40, 41) present in the mirror plane and orthogonal to the optical axis of the observation device (44). 18. A device for positioning an electronic element in a circuit support according to any one of items 17 to 17. 23. The device according to claim 22, wherein the two mirrors are pivoted together with the observation device as a unit.