JP2007000988A - Method and apparatus for drilling - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the positional error of holes to be formed on a substrate when a plurality of the holes are drilled at the same time on the substrate by using a plurality of drills. <P>SOLUTION: Workpieces are mounted on a table 3 which can move in the X-direction. A cross slide 6 is arranged above the table 3 and can move in the Y-direction perpendicular to the X-direction. A plurality of spindles 12 are mounted on the cross slide 6. A plurality of tools are supported on the tip ends of the respective spindles 12. Before the holes are drilled on the workpieces, the positional errors of the axes of a plurality of the tools in the X-direction and the Y-direction with respect to the designed axes of the spindles 12 are detected respectively, and the mean value of the detected positional errors for every direction is calculated. Then, the holes are drilled on the workpieces after correcting the coordinates of the axes of a plurality of the spindles 12 by the amount of the mean value for every direction with respect to the coordinates of the centers of the holes to be drilled. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the present invention, when a plurality of holes are simultaneously processed in a printed circuit board placed on one table by a plurality of drills, the position of the hole opened on the board is corrected by correcting the position of the axis of the drill. The present invention relates to a drilling method and a drilling device for reducing the size of the hole.

Along with the increase in the density of wiring and mounting parts of the printed board, the printed board has been multilayered.
At the same time as this multi-layering, there has been a need to process a blind hole for connecting a circuit on the surface of the printed circuit board and a circuit on the inner layer, or a spot facing process for attaching an IC or the like to the printed circuit board.

A printed circuit board drilling apparatus for simultaneously drilling a plurality of holes in the printed circuit board will be described with reference to FIG. FIG. 6 is a perspective view of a conventional printed circuit board drilling device.
Two guide rails 2 are fixed to the upper surface of the bed 1. A table 3 is movably supported on the guide rail 2. The table 3 is movable with respect to the bed 1 in the direction of arrow X in the figure. A column 4 is fixed to the upper surface of the bed 1. The column 4 has a U-shape, and both leg portions are fixed to the bed 1. The table 3 passes between both legs of the column 4.

  Two guide rails 5 are fixed to the front of the column 4. A cross slide 6 is movably supported on the guide rail 5. The cross slide 6 is movable with respect to the column 4 in the arrow Y direction in the figure orthogonal to the X direction. This movement is performed by the control device 40 controlling the motor 7 supported by the column 4 and rotationally driving a feed screw (not shown) supported by the column 4 in parallel with the guide rail 5.

  Four guide rails 16 are fixed to the cross slide 6. One saddle 8 is supported so as to be movable with respect to the two guide rails. The two saddles 8 are movable with respect to the cross slide 6 in the direction of the arrow Z in the figure, which are orthogonal to the X direction and the Y direction, respectively. This movement is performed by the control device 40 controlling the motor 10 supported by the cross slide 6 and rotationally driving a feed screw (not shown) rotatably supported by the cross slide 6.

  Two spindles 12 are fixed to each saddle 8. The spindle 12 is provided with a rotating shaft whose axis is on the same axis as the axis of the spindle 12 and a motor 9 for driving the rotating shaft. A chuck (not shown) is supported at one end of the rotating shaft. The chuck 11 holds the drill 11 so that its axis is on the same axis as the axis of the rotary shaft. That is, the axis of the spindle 12, the axis of the rotary shaft, and the axis of the drill 11 are all on the same axis.

  In the printed circuit board drilling device having such a configuration, the control device 40 rotates the spindle 12 at the time of drilling, so that the motor 9 is rotated at a high speed. Therefore, the motor 9 generates heat and the heat is transmitted to each part such as the saddle 8. Each part such as the saddle 8 is deformed by the influence of heat. Therefore, the axis line of the drill 11 will shift.

The deviation of the axis of the drill 11 will be described with reference to FIG. FIG. 7 is an explanatory diagram for explaining that the axis of the drill is displaced due to the influence of heat. Prior to the start of drilling, that is, before the motor 9 rotates, the axes of the four drills 11 have the same X-coordinate and different Y-coordinates as shown by the dotted lines in the figure. It is located at A2, the reference position A3, and the reference position A4.
The positions of the reference position A1, the reference position A2, the reference position A3, and the reference position A4 are positions on the design axis of the spindle 12, respectively.

  After the motor 9 rotates at a predetermined rotational speed, the axes of the four drills 11 are at the reference position as shown by the solid lines in the figure due to deformation of each part such as the saddle 8 due to the heat generated by the motor 9. Σ (x1), σ (x2), σ (x3), σ (x4) in the X direction and σ (y1), σ (in the Y direction from A1, the reference position A2, the reference position A3, and the reference position A4, respectively. y2), σ (y3), and σ (y4) are shifted. As described above, when the axis of the drill 11 is displaced, the position of the hole opened in the substrate is displaced.

  An example of a method for correcting the position of a hole opened in a substrate is disclosed in Japanese Patent Laid-Open No. 5-169352. According to the method disclosed in Japanese Patent Laid-Open No. Hei 5-169352, the position of a hole opened in a substrate can be corrected in a drilling device that forms a hole in a substrate with a single drill.

However, in this method, in the case where a plurality of holes are simultaneously processed with a plurality of drills on the substrate, the positions of the plurality of drills cannot be corrected independently. The position cannot be corrected at the same time.
JP-A-5-169352

  An object of the present invention is to reduce the displacement of the positions of holes formed in a substrate when a plurality of holes are simultaneously processed in a substrate with a plurality of drills.

  The present invention provides a table that is movable in the X direction, a cross slide that is arranged above the table and that is movable in the Y direction perpendicular to the X direction, the axis direction is the X direction, and the Y direction. A plurality of spindles mounted on the cross slide with the same X-coordinate of the axis and different Y-coordinates, and having a hole to be machined with a design axis of the spindle. A plurality of workpieces placed on the table by a plurality of tools that are positioned at the center coordinates and are supported at the tips of the plurality of spindles so that their axes are on the same axis as the axes of the plurality of spindles. In the drilling method of the drilling device for drilling holes simultaneously, before drilling the workpiece, the X direction of the plurality of tool axes with respect to the spindle design axis , And detecting a deviation for each direction in the Y direction, calculating an average value of the detected deviations for each direction, and using the coordinates of the axes of the plurality of spindles as the center coordinates of the hole to be machined On the other hand, a hole is made in the workpiece by correcting the average value for each direction.

  Further, a drilling method for a drilling apparatus, further comprising a plurality of temperature sensors for detecting temperatures of a plurality of motors that respectively rotate the plurality of spindles, the temperature detected by the plurality of temperature sensors. When at least one exceeds a predetermined value set in advance, a deviation in each direction of the X direction and the Y direction with respect to the spindle design axis of the plurality of tools is detected and detected. The average value of the deviation for each direction is calculated, and the coordinates of the axis lines of the plurality of spindles are corrected by the average value for each direction with respect to the center coordinates of the hole to be machined, It is also possible to make a hole in the workpiece.

  Further, an average of deviations in the X direction and the Y direction of the plurality of tool axes with respect to the design axis of the spindle when the plurality of spindles are rotated at a predetermined number of rotations for a predetermined time. Instead of obtaining an average value of deviations in each of the X direction and the Y direction when the plurality of spindles are rotated at a certain number of revolutions for a predetermined time. Using the average value of the deviation for each direction obtained in advance, the coordinates of the axes of the plurality of spindles are corrected by the average value for each direction with respect to the center coordinates of the hole to be machined, It is also possible to make a hole in the workpiece.

  Further, a table movable in the X direction, a cross slide disposed above the table and movable in the Y direction perpendicular to the X direction, and the axis direction orthogonal to the X direction and the Y direction. And a plurality of spindles placed on the cross slide with the same X coordinate of the axis and changing the Y coordinate, and the center coordinates of the hole in which the designed axis of the spindle is to be machined And a plurality of holes are formed in the workpiece placed on the table by a plurality of tools supported at the respective tips of the plurality of spindles so that their axes are on the same axis as the axes of the plurality of spindles. A drilling device that simultaneously drills, wherein before drilling the workpiece, the X direction of the plurality of tool axes relative to the design axis of the spindle, and the Y A deviation for each direction of the direction is detected by a sensor, an average value of the detected deviations for each direction is calculated, and the coordinates of the axes of the plurality of spindles are compared with the center coordinates of the hole to be machined. It is also possible to make a hole in the workpiece by correcting the average value for each direction.

  According to the drilling method and the drilling apparatus of the present invention, since the displacement of the position of the hole drilled in the substrate can be reduced, the hole can be drilled in the substrate with high accuracy.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, a printed circuit board drilling apparatus that executes the drilling method of the present invention will be described with reference to FIG. FIG. 1 is a perspective view of a printed circuit board drilling apparatus that executes the drilling method of the present invention. The configuration of the printed circuit board drilling apparatus for executing the drilling method of the present invention shown in FIG. 1 is substantially the same as the configuration of the conventional printed circuit board drilling apparatus shown in FIG. However, the point which the sensor 13 which detects the position of the drill 11 is provided on the table 3 differs from the conventional printed circuit board drilling apparatus. The configuration of the control device 40 is the same as the configuration of the control device 40 of the conventional printed circuit board drilling device, but is a program that executes the drilling process described with reference to FIG. Is different.

[About the sensor configuration for detecting the position of the drill]
Next, the configuration of a sensor that detects the position of the drill will be described with reference to FIG. FIG. 2 is a cross-sectional view in the X-axis direction of a sensor that detects the position of the drill. As shown in FIG. 2, the sensor 13 includes a housing 25 fixed on the table 3, a lamp 26, a lens 27, a columnar lens 28, and a charge coupled device 29. A hole 30 for inserting the drill 11 is formed between the lens 27 and the columnar lens 28. Further, the sensor 13 includes a lamp 26, a lens 27, a columnar lens 28, and a charge coupled device 29 in the Y-axis direction as in the X-axis direction.

  The control device 40 controls the motor 9 to rotate the drill once with the drill 11 inserted in the hole 30. The charge coupled device 29 detects the shadow of the drill 11 irradiated on the lamp 26 while the drill 11 rotates once. Information about the detected shadow of the drill 11 is transmitted to the control device 40. The control device 40 extracts the contour of the drill 11 based on the acquired maximum shadow value of the drill 11.

  The control device 40 detects the axis of the drill 11 by calculating the area centroid of the contour of the extracted drill 11. The control device 40 calculates the deviation of the axis of the drill 11 from the designed axis in the Y-axis direction based on the axis of the drill 11 thus determined.

  Then, the control device 40 executes the same processing as calculating the deviation of the axis of the drill 11 from the design axis in the Y-axis direction, so that the design axis of the axis of the drill 11 in the X-axis direction is determined. The deviation is calculated.

[Example 1]
Next, Example 1 will be described with reference to FIG. FIG. 3 is a flowchart for explaining the first embodiment.
A condition for the user of the printed circuit board drilling device to measure the displacement (including the sign) of the position in the X direction and the Y direction from the respective reference positions of the axes of the four drills in the memory built in the control device 40 Is stored in advance. For example, the user can store an arbitrary condition in the memory in advance so that the deviation of the axis of the drill is measured every time all holes are processed in one substrate.
In the process of step S10, the control device 40 determines whether or not to measure deviations in the X direction and Y direction positions from the reference positions of the axes of the four drills. When measuring the deviations from the reference positions of the axes of the four drills, the process proceeds to step S11.

In the process of step S11, the control device 40 detects the axes of the four drills before executing the drilling process on the substrate.
In the process of step S12, the control device 40 calculates the deviation of the positions in the X direction and the Y direction from the respective reference positions of the axis lines of the four drills.

  In the process of step S13, the control device 40 is based on the following formulas 1 and 2 that show the average Xmean of the deviation in the X direction from the reference position of the axis of the four drills and the average Ymean of the deviation in the Y direction, respectively. calculate. Σ (x1), σ (x2), σ (x3), and σ (x4) shown in Equation 1 are respective deviations in the X direction from the reference position of the axis line of the four drills. Σ (y1), σ (y2), σ (y3), and σ (y4) shown in Equation 2 are the respective deviations in the Y direction from the reference position of the axes of the four drills.

    Xmean = (σ (x1) + σ (x2) + σ (x3) + σ (x4)) / 4 (Expression 1)

    Ymean = (σ (y1) + σ (y2) + σ (y3) + σ (y4)) / 4 (Expression 2)

In the process of step S14, the control device 40 reads the data of the hole to be processed from the built-in memory.
In the process of step S15, the control device 40 corrects the data for moving the table 3 and the cross slide 6 based on the Xmean and Ymean calculated in the process of step S13. That is, when the data of the center coordinate of the hole to be opened next is (a, b), the data of the center coordinate of the hole is only the average of the deviations in the X direction and the Y direction shown in Equations 1 and 2. Corrections are made to distant coordinates (a + Xmean, b + Ymean).

Here, correction of the positions of the table 3 and the cross slide 6 will be described with reference to FIGS. First, the correction of the position of the table 3 will be described with reference to FIG. FIG. 4 is an explanatory diagram for explaining the correction of the position of the table 3.
As shown in FIG. 4, due to the deformation of each part such as the saddle 8 due to the influence of the heat generated by the motor 9, the axes of the four drills 11 are changed from the reference position A1, the reference position A2, the reference position A3, and the reference position A4, respectively. They are shifted by σ (x1), σ (x2), σ (x3), and σ (x4) in the X direction. If a hole is drilled in the substrate in this state, the displacement of the hole with respect to each reference position becomes large.

Therefore, the position of the table 3 is corrected by the correction amount shown in Equation 1. Here, when σ (x11), σ (x22), σ (x33), and σ (x44) are respectively shifted in the X direction from the corrected positions of the axes of the four drills, the corrected positions The total sum σ (x11) + σ (x22) + σ (x33) + σ (x44) of the displacement of each hole with respect to is zero.
Accordingly, the sum σ (x11) + σ (x22) + σ (x33) + σ (x44) of the displacement of each hole with respect to the corrected position is the sum σ (x1) + σ (x2) of the displacement of each hole with respect to the reference position. It is less than the absolute value of + σ (x3) + σ (x4).
In the example shown in FIG. 4, the absolute value of the maximum value σ (x11) of the hole displacement with respect to the corrected position is equal to or smaller than the absolute value of the maximum value σ (x1) of the hole displacement with respect to the reference position. .

Next, correction of the position of the cross slide 6 will be described with reference to FIG. FIG. 5 is an explanatory diagram for explaining correction of the position of the cross slide 6.
As shown in FIG. 5, due to the deformation of each part such as the saddle 8 due to the influence of heat generated by the motor 9, the axes of the four drills 11 correspond to the reference position A 1, the reference position A 2, the reference position A 3, and the reference position. The position A4 is shifted by σ (y1), σ (y2), σ (y3), and σ (y4) in the Y direction. If each hole is drilled in the substrate in this state, the displacement of each hole with respect to the reference position A1, the reference position A2, the reference position A3, and the reference position A4 becomes large.

Therefore, the position of the cross slide 6 is corrected by the correction amount shown in Equation 2. Here, assuming that σ (y11), σ (y22), σ (y33), and σ (y44) are offset in the Y direction from the respective correction positions of the four drill axes, the respective correction positions A1, The total sum σ (y11) + σ (y22) + σ (y33) + σ (y44) of the displacement of each hole with respect to the correction position A2, the correction position A3, and the correction position A4 is 0.
Therefore, the total sum σ (y11) + σ (y22) + σ (y33) + σ (y44) of the displacements of the holes with respect to the correction position A1, the correction position A2, the correction position A3, and the correction position A4 is the respective reference. The absolute value of the sum σ (y1) + σ (y2) + σ (y3) + σ (y4) of the displacements of the holes with respect to the position A1, the reference position A2, the reference position A3, and the reference position A4 is less than or equal to the absolute value.

  When the process of step S15 is completed, and in the process of step S10, the control device 40 determines not to measure the deviations in the X and Y directions from the respective reference positions of the axes of the four drills. If so, the process proceeds to step S16.

  In the process of step S16, the control device 40 moves the table 3 and the cross slide 6 so that the axes of the four drills are located at the coordinates (a + Xmean, b + Ymean).

  In the process of step S17, the control device 40 executes a processing process for making a hole in the substrate. Specifically, the control device 40 rotates the motor 9 while rotating the feed screw rotatably supported by the cross slide 6 by the motor 10 to move the two saddles 8 vertically in the Z direction in FIG. Move it down to make a hole in the substrate.

  In the process of step S18, the control device 40 determines whether or not there is a next hole to be processed. If there is a next hole to be processed, the control device 40 returns to the process of step S10 and executes the subsequent processes again. If there is no next hole to be processed, the control device 40 proceeds to step S19.

  In the process of step S19, the control device 40 determines whether there is a next substrate to be processed. If there is a next substrate to be processed, the control device 40 returns to the process of step S10 and executes the subsequent processes again. When there is no next substrate to be processed, the control device 40 ends the process.

[Example 2]
Next, a second embodiment different from the first embodiment will be described. In the second embodiment, a temperature sensor 15 is provided on the side surface of the motor 9 as indicated by a dotted line in FIG.
The manufacturer of the printed circuit board drilling device can experimentally obtain in advance the relationship between the temperature detected by the temperature sensor 15 and the deviation of the axis of the drill 11 from the reference position. The manufacturer of the printed circuit board drilling device stores the relationship between the temperature thus determined and the deviation of the drill axis from the reference position in a memory built in the control device 40 in advance.
The user of the printed circuit board drilling device determines the temperature at which it is necessary to correct the position of the hole drilled in the board based on the relationship between the temperature stored in the memory and the deviation of the drill axis from the reference position. Then, the temperature is stored in advance in a memory built in the control device 40 as a predetermined value.

The control device 40 determines whether or not at least one of the temperatures detected by the temperature sensor 15 is equal to or less than a predetermined value.
When at least one of the temperatures detected by the temperature sensor 15 is greater than a predetermined value, the control device 40 performs each process described in the first embodiment (Step S11, Step S12, Step S13, FIG. 3). Steps S14, S15, S16, and S17) are executed.
When all the temperatures detected by the temperature sensor 15 are equal to or lower than a predetermined value, the control device 40 executes the processing as it is.

  In general, the temperature of a motor increases with processing and becomes constant (saturates) at a certain temperature. Therefore, if a plurality of predetermined values of the temperature are determined and the deviation of the drill axis from the reference position is obtained every time the temperature of the sensor reaches any of the predetermined values, the processing starts from a state where the motor is cooled. Even in this case, the processing accuracy can be improved. Moreover, since the warm-up operation of the printed circuit board drilling device is not necessary, the processing efficiency of the printed circuit board can be improved.

Further, when the predetermined value is one, the process of making a hole in the printed circuit board is continued, and when the temperature of the motor 9 continues to rise until the temperature becomes constant, each process described in the first embodiment is performed. This is repeatedly executed, and the processing efficiency of the printed circuit board is reduced.
However, when there are a plurality of predetermined values, each process described in the first embodiment is not executed unless at least one of the temperatures detected by the temperature sensor 15 exceeds a predetermined value corresponding to the next lower temperature. Therefore, in this case, it is possible to prevent the processing efficiency of the printed circuit board from being lowered.

  Thus, in the second embodiment, the control device 40 corrects the positions of the table 3 and the cross slide 6 when at least one of the temperatures detected by the temperature sensor 15 is greater than a predetermined value. .

Example 3
Next, a third embodiment different from the first and second embodiments will be described. In the third embodiment, the control device 40 first determines whether or not the motor 9 has rotated at a certain rotational speed for a predetermined time.
The manufacturer of the printed circuit board drilling device can experimentally determine in advance the deviation of the axis of the drill 11 from the reference position when the motor 9 rotates at a certain rotational speed for a predetermined time. The manufacturer of the printed circuit board drilling device stores the relationship between the predetermined time thus obtained and the deviation of the drill axis from the reference position in a memory built in the control device 40 in advance.
The predetermined time when the user of the printed circuit board drilling device needs to correct the position of the hole drilled in the board based on the relationship between the predetermined time stored in the memory and the deviation of the drill axis from the reference position The predetermined time is stored in advance in a memory built in the control device 40.

When the motor 9 rotates at a certain number of revolutions for a predetermined time, the control device 40 executes each process described in the first embodiment (each process in step S14, step S15, step S16, and step S17 in FIG. 3). .
When the motor 9 does not rotate at a certain rotation speed for a predetermined time, the control device 40 executes the processing as it is.

  Thus, in the third embodiment, the control device 40 corrects the positions of the table 3 and the cross slide 6 when the motor 9 rotates at a certain rotation speed for a predetermined time.

  In addition, in Example 1, Example 2, and Example 3, it demonstrated taking the example of the drilling method in the case of processing simultaneously the printed circuit board placed on one table with four drills. However, the drilling method of the present invention can be executed not only in the case of four drills but also in the case of simultaneously processing a printed circuit board placed on one table with a plurality of drills. Needless to say, the drilling method of the present invention can be executed even when a workpiece other than a printed circuit board is processed.

  Furthermore, in the case of simultaneously processing a printed circuit board placed on one table with a plurality of drills, if there is a drill that is not used, the reference position of the axis line of each drill excluding the drill that is not used is used. The positions of the table and the cross slide can be corrected based on the average of the deviations.

It is a perspective view of the printed circuit board drilling apparatus which performs the drilling method of this invention. It is sectional drawing of the X-axis direction of the sensor which detects the position of a drill. 3 is a flowchart for explaining Example 1; It is explanatory drawing for demonstrating correction | amendment of the position of a table. It is explanatory drawing for demonstrating correction | amendment of the position of a cross slide. It is a perspective view of the conventional printed circuit board drilling apparatus. It is explanatory drawing for demonstrating that the center position of a drill will shift | deviate from a reference position by the influence of heat.

Explanation of symbols

1 bed 2 guide rail 3 table 4 column 5 guide rail 6 cross slide 7 motor 8 saddle 9 motor 10 motor 11 drill 12 spindle 13 sensor 16 guide rail 40 controller

Claims (4)

A table movable in the X direction;
A cross slide disposed above the table and movable in a Y direction perpendicular to the X direction;
The direction of the axis is the X direction and the Z direction perpendicular to the Y direction,
A plurality of spindles placed on the cross slide with the same X-coordinate of the axis and changing the Y-coordinate,
Positioning the design axis of the spindle at the center coordinates of the hole to be machined;
Drilling a plurality of holes simultaneously on a workpiece placed on the table by a plurality of tools supported at the tips of the plurality of spindles so that their axes are on the same axis as the axes of the plurality of spindles. In the drilling method of the device,
Before making a hole in the workpiece,
Detecting a deviation in each direction of the X direction and the Y direction with respect to the design axis of the spindle of the axes of the plurality of tools;
Calculate the average deviation detected for each direction,
A correction of the average value for each direction with respect to the center coordinate of the hole to be machined with the coordinates of the axes of the plurality of spindles,
A method of drilling, characterized in that a hole is drilled in the workpiece. A drilling method for a drilling device, further comprising a plurality of temperature sensors that respectively detect temperatures of a plurality of motors that respectively rotate the plurality of spindles,
The drilling method according to claim 1, wherein the drilling method according to claim 1 is executed when at least one of the temperatures detected by the plurality of temperature sensors exceeds a predetermined value set in advance. Average values of deviations in the X direction and the Y direction of the plurality of tool axes when the plurality of spindles are rotated at a predetermined number of rotations for a predetermined time with respect to the spindle design axis. Find each in advance,
When the plurality of spindles rotate at a certain rotation speed for a predetermined time,
The average value of the deviation for each direction obtained in advance is used instead of obtaining the average value of the deviation for each direction in the X direction and the Y direction. How to drill holes. A table movable in the X direction;
A cross slide disposed above the table and movable in a Y direction perpendicular to the X direction;
The direction of the axis is the X direction and the Z direction perpendicular to the Y direction,
A plurality of spindles placed on the cross slide with the same X-coordinate of the axis and changing the Y-coordinate,
Positioning the design axis of the spindle at the center coordinates of the hole to be machined;
Drilling a plurality of holes simultaneously on a workpiece placed on the table by a plurality of tools supported at the tips of the plurality of spindles so that their axes are on the same axis as the axes of the plurality of spindles. A device,
Before making a hole in the workpiece,
A sensor detects a deviation of each axis of the plurality of tools with respect to the design axis of the spindle in each of the X direction and the Y direction.
Calculate the average deviation detected for each direction,
A correction of the average value for each direction with respect to the center coordinate of the hole to be machined with the coordinates of the axes of the plurality of spindles,
A drilling device that drills holes in the workpiece.

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