Electronic component mounting apparatus with setting device setting measurement positions for printed board

An electronic component mounting apparatus includes a component feeding device that supplies an electronic component to a pickup position, a suction nozzle that picks up the electronic component supplied to the pickup position and mounts the picked up electronic component on a printed board, a height level detection device that measures height levels of the printed board positioned in a mounting position, a monitor graphically that displays a warping state of a sample printed board positioned in the mounting position based on height level measurements by the height level detection device on predetermined positions of the sample printed board, a setting device that sets measurement positions for actual mounting operations using the monitor, a converting device that converts the set measurement positions into coordinates on the printed board, and a memory that stores the converted coordinates of the set measurement position.

CROSS-REFERENCE OF THE INVENTION

This application claims priority from Japanese Patent Application No. 2007-117762, the content of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an electronic component mounting apparatus for picking up electronic components from a component feeding device by suction by suction nozzles and mounting the electronic components on a positioned printed board. In detail, the invention relates to a method of mounting an electronic component and an electronic component mounting apparatus in which electronic components are picked up from a component feeding device by suction by suction nozzles, a height level of a positioned printed board is measured by a height level detection device, and the electronic components are mounted on the printed board based on the measurement result of this height level detection device.

2. Description of the Related Art

A general electronic component mounting apparatus is disclosed in Japanese Patent Application publication No. 2006-286707 and so on, for example. In some cases, due to a warp of a printed board, electronic micro-components may be brought back instead of mounted, crack, or scatter solders in the mounting operation. Therefore, the lowering of suction nozzles during the mounting of electronic components is controlled, using a device for detecting a height level of a board such as a laser displacement gauge and based on its measurement result.

However, a plurality of positions for height measurement need be set on a printed board, taking account of the warping state or curvature of the board, and inputting the coordinates of the measurement positions is a complicated work. The invention realizes setting of measurement positions suitable for a warping state of a printed board and an easy work of setting the measurement positions.

SUMMARY OF THE INVENTION

The invention provides a method of mounting an electronic component in which an electronic component is picked up from a component feeding device by suction by a suction nozzle, a height level of a positioned printed board is measured by a height level detection device, and the electronic component is mounted on the printed board based on the measurement result of the height level detection device, the method including: measuring a warping state of a positioned printed board as a measurement sample by the height level detection device; displaying the warping state of the printed board graphically on a monitor based on the measurement result; setting a measurement position on the displayed graphic; and converting the set measurement position into coordinates on the printed board and storing the coordinates in a memory.

The invention also provides an electronic component mounting apparatus in which an electronic component is picked up from a component feeding device by suction by a suction nozzle, a height level of a positioned printed board is measured by a height level detection device, and the electronic component is mounted on the printed board based on the measurement result of the height level detection device, including: a monitor graphically displaying a warping state of a positioned printed board as a measurement sample based on a result of measuring the warping state of the printed board by the height level detection device; a setting device setting a measurement position on the displayed graphic; a converting device converting the measurement position set by the setting device into coordinates on the printed board; and a memory storing the converted coordinates of the set position.

DETAILED DESCRIPTION OF THE INVENTION

An embodiment of an electronic component mounting apparatus for mounting electronic components on a printed board will be described referring to figures.FIG. 1is a plan view of an electronic component mounting apparatus1, and a plurality of component feeding units3supplying various electronic components to these component pickup portions (component suction positions) one by one is arrayed on a base2of the apparatus1. A supplying conveyer4, a positioning portion5and a discharging conveyer6are provided between the opposite groups of component feeding units3. The supplying conveyer4carries a printed board P received from an upstream device to the positioning portion5, the printed board P is positioned by a positioning mechanism (not shown) on the positioning portion5, electronic components are mounted on the printed board P, and the printed board P is carried to the discharging conveyer6.

Numerals8A and8B indicate a pair of beams extending in the X direction, which separately move in the Y direction along a pair of left and right guides11above a printed board P or above the component pickup portions (component suction positions) of the component feeding units3by rotation of screw axes10driven by Y axis motors9, respectively.

The beams8A and8B are respectively provided with mounting heads7A and7B moving in the longitudinal direction of the beams8A and8B, that is, in the X direction along guides (not shown) by X axis motors12. Two vertical axis motors13vertically moving two suction nozzles17A and17B or two suction nozzles17C and17D are mounted on each of the mounting heads7A and7B, and two θ axis motors14rotating these suction nozzles about vertical axes are further mounted thereon. Therefore, the suction nozzles of each of the two mounting heads7A and7B are movable in the X and Y directions, rotatable about vertical axes, and movable vertically.

Numerals16indicate component recognition cameras, which take images of electronic components held by the suction nozzles17A,17B,17C and17D. Numerals18indicate height level detection devices such as laser displacement gauges provided on the mounting heads7A and7B respectively, which measure a height level of a printed board P positioned on the positioning portion.

Next, referring to a control block diagram inFIG. 2, a CPU30controls the members of the electronic component mounting apparatus1, and is connected to a ROM31storing programs for this control and a RAM32storing various data through bus lines33. A monitor34displaying an operation screen or the like and a touch panel switch35as input means formed on the display screen of the monitor34are connected to the CPU30through an interface36. The Y axis motor9and so on are connected to the CPU30through a drive circuit38and the interface36. The touch panel switch35may be replaced by a keyboard or other input means, and operation means such as a mouse may be further connected to the CPU30.

The RAM32is stored with mounting data for each of types of printed boards P for the component mounting operation, in which data about mounting coordinates of each of electronic components in the X and Y directions on the printed board P and the angle thereof, data about the alignment numbers of the component feeding units3or the like are stored in mounting order (in step number order). The RAM32is also stored with data about types of electronic components corresponding to the alignment numbers of the component feeding units3, i.e., component disposition data, and further stored with component library data about the lengths of the electronic components in the X and Y directions and the thicknesses thereof, nozzle IDs of suction nozzles used for electronic components, or the like classified by the component IDs.

Furthermore, the RAM32is also stored with numerous measurement positions for measuring a warping state of a printed board P by the height level detection device18, for example, coordinate data (measurement position data) about numerous measurement positions finely set at equal intervals over the whole regions of a printed board P.

A numeral37is a recognition processing device connected to the CPU30through the interface36, which performs recognition processing to an image taken and stored by the component recognition camera16and sends the processing result to the CPU30. In detail, the CPU30outputs a command to perform recognition processing (such as calculation of an positional shifting amount) to an image taken by the component recognition camera16to the recognition processing device37, and receives the recognition processing result from the recognition processing device37. However, the measurement points are not used when electronic components are mounted.

Selection may be made whether the warping state of the printed board P is displayed three-dimensionally as shown inFIG. 4or by contour lines as shown inFIG. 5, based on a measurement result about height levels measured by the height level detection device18according to the measurement position data, by touch-operating the touch panel switch35while watching a selection screen displayed on the monitor34. Therefore, according to the selected display program stored in the ROM31, the CPU30displays the warping state of the printed board P on the monitor34three-dimensionally or by contour lines.

The three-dimensional display of the printed board P may be shifted, that is, the side of the printed board P to watch may be changed by operation of an operator.

In this case, for example, the screen indicates that the A region of the printed board P is on the level higher than the reference level by 0.550 to 0.600 mm by warping upward and similarly the B region is on the level higher than the reference level by 0.500 to 0.550 mm.

The height levels may be displayed with different colors or patterns in each of the regions, or with different colors in each of the grid-partitioned regions of the substrate, for example.

Next, a description will be given referring to a flow chart inFIG. 3, hereafter. First, by an operator, a printed board P as a measurement sample is mounted on the positioning portion5, and the positioning mechanism is activated to position the printed board P three-dimensionally in the X, Y and vertical directions by touch-operating the touch panel switch35displayed on the monitor34. Then, the backup base (not shown) which has a plurality of holes where backup pins necessary for the printed board P for the manufacturing process are inserted is lifted up to apply the backup pins to the back surface of the printed board P and to push up and support the board P horizontally.

Then, the warping state of the printed board P is measured by touch-operating the touch panel switch35. At this time, according to the touch-operation of the touch panel switch35, the CPU30controls the X axis motor12and the Y axis motor9to move the height level detection device18, controls the height level detection device18to measure the height levels of the printed board P in the measurement positions based on the coordinate data (measurement position data) about numerous measurement positions stored in the RAM32, and stores the measurement result in the RAM32.

Then, the CPU30graphically displays the warping state of the printed board P on the monitor34as shown inFIG. 4when the three-dimensional display is selected or as shown inFIG. 5when the contour line display is selected, based on the measurement result.

At this time, the operator may set the measurement positions on either of the displays on the screen by touch-operation on the screen. In detail, touching the positions to be measured means operating the touch panel switch35on the monitor34, and thus the operator easily sets the measurement positions while watching the warping state of the board which is graphically displayed. In this case, black portions inFIG. 6are the set positions, and white circle portions inFIG. 7are the set positions. The position may be set by indicating it by a cursor (not shown) and pressing an enter key, or by clicking a mouse.

One of the screens ofFIG. 6andFIG. 7may be used to set some positions by touch-operation, and then the other screen may be selected to set other positions. At this time, the measurement positions which are already set remain displayed on the switched screen. The screen may be switched after all the measurement positions are set, and enhanced setting of measurement positions may be achieved by checking both the screens. Furthermore, the set measurement position may be canceled to omit an unnecessary measurement position. The canceling method includes clicking a mouse on the set points twice, or using a touch panel switch, for example, touching a “delete” portion displayed on the screen.

After the setting, the CPU30converts each of the set positions into coordinates on the printed board P, writes the coordinates of each of the set positions in the top of the mounting data as shown inFIG. 8, and stores the data in the RAM32. For example, for the step number0001, XX1and YY1are written as the X coordinate and the Y coordinate, and “W” is written as the command of the mounting data about the measurement positions, which is distinguished from the mounting data about the mounting positions of the electronic components.

Hereafter, an operation with the above structure will be described. First, a printed board P is received by the supplying conveyer4from an upstream device (not shown), and the printed board P on the supplying conveyer4is carried onto the positioning portion5.

At this time, the printed board P is positioned three-dimensionally in the X, Y and vertical directions by the positioning mechanism, and the backup base (not shown) having the holes where the backup pins necessary for the printed board P for the manufacturing process are inserted is lifted up to apply the backup pins to the back surface of the printed board P and to push up and support the board P horizontally.

The positioning operation for the printed board P is completed in this manner. When judging the completion of the positioning operation, the CPU30controls the X axis motor12and the Y axis motor9to move the mounting head7A or7B and the detection device18. In this case, the CPU30moves the height level detection device18to the position above the coordinates of the measurement position indicated by the step number0001and detects the height level of the printed board P there according to the mounting data shown inFIG. 8stored in the RAM32, and similarly moves the height level detection device18to the position above the coordinates indicated by the step number0002and detects the height level of the printed board P there. The CPU30then repeats the detection of the height levels on all the set measurement coordinates, and stores the height level data as the measurement values in the RAM32.

At this time, the number of measurement positions is minimized and the time for detecting the height levels of the board is reduced since the measurement positions are set on the screen graphically displaying the state of the board.

Then, the suction nozzle17A,17B,17C or17D picks up an electronic component to be mounted from the predetermined component feeding unit3, according to the mounting data stored in the RAM32, where the position of the X and Y coordinates and the rotation angle about the vertical axis for mounting the electronic component on the printed board P positioned on the positioning portion5, the FDR number (the alignment number of each of the component feeding units3) and so on are set, next to the mounting data about the measurement positions.

In detail, if the suction nozzle17A of the mounting head7A corresponds to the type of the electronic component, the suction nozzle17A moves to the position above the component feeding unit3storing the first electronic component to be mounted. In detail, as described above, the mounting head7A is moved in the Y direction by the beam8A moving along the pair of guides11by the Y axis motor9, and is moved in the X direction by the X axis motor12. The predetermined feeding unit3is already driven and the electronic component is ready to be picked up on the component pickup position. Then, the vertical axis motor13is driven to lower the nozzle17A and the nozzle17A picks up the electronic component by suction. The suction nozzle17B then moves to the position above the component feeding unit3storing the next electronic component to be mounted and picks up the electronic component.

Furthermore, the suction nozzles17A and17B move to the position above the component recognition camera16, and the component recognition camera16takes images of the electronic components held by suction, and the recognition processing device37performs recognition processing to the images. Based on the recognition result, the beam8A and the mounting head7A are moved again, and the suction nozzles17A and17B correct the positional shifts of the components by adding the component recognition result to the mounting coordinates in the mounting data and mount the electronic components on the printed board P respectively.

At this time, the suction nozzles17A and17B, which pick up electronic components by suction and mount the electronic components on a printed board P by rotating by the θ axis motors14and lowering by the vertical axis motors13respectively, use the measurement values when mounting the electronic components. In detail, based on the measurement values of the height levels of the printed board P corresponding to the component mounting positions, the CPU30controls the lowering of the suction nozzles17A and17B. It means that the CPU30decreases the lowering amount when the printed board P is warped upward, and increases the lowering amount when the printed board P is warped downward.

As described above, the invention provides an electronic component mounting apparatus which achieves setting of measurement positions suitable for a warping state of a printed board and provides an easy work of setting the measurement positions.

Although an embodiment of the invention is described above, those skilled in the art would understand that various substitutions, changes or modifications are possible based on the above description and the invention includes the various substitutions, changes or modifications within the scope of the invention.