JP2955633B2 - Drilling method with printed circuit board drilling machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention can always suppress the vicinity where a drill hole is formed in a printed circuit board, regardless of the size of the drill diameter, without using a contact plate placed on the top of the printed circuit board during boring of the printed circuit board. Also, the present invention relates to a method for drilling a printed circuit board by a printed circuit board drilling machine, which can more reliably drill a printed circuit board without generating burrs on the printed circuit board.

[Prior art]

Generally, a printed board drilling machine has a configuration as shown in FIG. In the drawing, reference numeral 1 denotes a printed board drilling machine, 3 denotes a bed, 2 denotes a table, which is slidably supported on the bed 3 and driven by a driving means (not shown). 4 is a drill, a holder 5 fixed to the table 2
Is held in. Reference numeral 6 denotes a column which is provided on the bed 3 so as to straddle the table 2. Reference numeral 7 denotes a spindle carriage which is slidably supported by the column 6 and is driven by the operation of a Y-axis drive motor 8. Reference numeral 9 denotes a spindle saddle, which is slidably supported by the spindle carriage 7, and
It is driven by the operation of the shaft drive motor 10. Reference numeral 11 denotes a spindle, which is supported by a spindle saddle 9 and rotated by the operation of a motor. 13 is a pressure foot. W
Denotes a printed board (hereinafter, simply referred to as a board), which is fixed to the table 2 via reference pins P. Then, the table 2 and the spindle carriage 7 are XY
After the relative movement in the direction, the printed board W and the spindle 11 are positioned, the spindle 11 is moved in the Z direction, and a hole is drilled in the board with the drill 4 held at the tip. As a spindle unit including a pressure foot, there is a spindle unit having a configuration as shown in FIG. That is, in the drawing, reference numeral 2 denotes a table of the drilling machine 1. A ball screw 14 moves the table 2 in the X direction by a servo motor (not shown). Reference numeral 15 denotes a printed circuit board on which a plurality of sheets are stacked.
This printed circuit board is placed on the upper side via a lower plate 16.
The contact plate 17 is placed on the reference numeral 15. Reference numeral 7 denotes a spindle carriage, and a Y-axis drive motor 8 and a ball screw 18
It is configured to be movable in the direction. A spindle saddle 9 is mounted on the spindle carriage 7, and can be driven in the Z direction by a Z-axis drive motor 10 and a ball screw 20. The spindle saddle 9 has a spindle 21 and an air cylinder 22 incorporated therein.
At the tip of 22, a pressure foot 23 is arranged.
In the above-described configuration, after the printed board 15 is positioned by the spindle carriage 7 and the table 2, the spindle saddle 9 descends, the pressure foot 23 presses the contact plate 17, and then the spindle 21 advances to move the printed board 15
Make a hole. On the printed circuit board 15, a contact plate 17 is placed, and below the printed circuit board 15, a lower plate 16 is laid. The lower plate 16 is used for the purpose of preventing the drill 16 from making a hole in the table 2.
Is used for the purpose of improving the biting of the drill 16 and for preventing burrs when the drill 16 comes out, and generally, an aluminum plate of 0.15 mm to 0.2 mm is used. The spindle of the printed circuit board drilling machine 1
Some are configured as shown in the figure. In the figure, reference numeral 29 denotes a spindle housing, which is fixed to the spindle saddle 9. The spindle housing 29 has a large-diameter hole 30 and a flange 31 protruding inward at one end of the hole 30.
Connected to a source of compressed air. A spindle body 33 is fitted and supported by a spindle housing 29 and rotatably supports the spindle 26. A motor 27 is supported at one end of the spindle body 33 and is coupled to the spindle 26. A chuck 34 is fixed to the lower end of the spindle 26 and holds the drill 24. Reference numeral 35 denotes a piston, which is formed with a flange 37 slidably fitted in a space 36 formed by the hole 30 of the spindle housing 29 and the spindle body 33. Reference numeral 28 denotes a pressure foot, which is fixed to one end of the piston 35. An exhaust port 38 connected to a vacuum suction source is formed on a side surface of the fresher foot 28, and a groove 39 for sucking air during drilling is formed on a lower surface.

[Problems to be solved by the invention]

In the former spindle part of the printed circuit board drilling machine 1 shown in FIG. 19, the inner diameter R1 of the pressing part 23 of the printed circuit board 15 of the pressure foot 23 is made larger than the diameter R2 of the maximum diameter drill 40 as shown in FIG. For this reason, when a small diameter drill 41 is used, as shown in FIG.
Is easily broken. Further, when the drills 40 and 41 come off the printed board 15, burrs appear on the upper side of the printed board 15, and the printed board 15 becomes defective. The plate 17 must be placed on the top of the printed circuit board 15 every time the printed circuit board 15 is replaced so that burrs are not generated on the upper side of the printed circuit board 15 when the drill is removed. Board
17 has a problem that it has to be disposable and is uneconomical. The spindle portion of the printed circuit board drilling machine 1 shown in FIG. 20 supplies compressed air of a predetermined pressure from the pipe 32 to move the piston 35 to the lower end of the spindle housing 29. In addition, through the exhaust port 38, the pressure foot 28
Exhaust the inside. At this time, as shown in FIG. 23, the air is sucked through the opening at the lower end of the pressure foot 28 and discharged through the exhaust port 38. Now, when the spindle saddle 9 shown in FIG. 18 is lowered, the pressure foot 28 presses the printed circuit board W as shown in FIG.
24 is pressed into the printed circuit board W, and a hole is formed. At this time, the air is sucked into the pressure foot 28 through the groove 39 and then discharged through the exhaust port 38. The drill 24 is cooled and chips are discharged by the flow of air sucked from the opening or the groove 39 of the pressure foot 28. Further, when the drill 24 comes off the printed board W, burrs appear on the upper side of the printed board W, and the printed board W becomes defective. Thus, even in the latter printed circuit board drilling machine, the plate 42 is placed on the uppermost stage of the printed circuit board W, and the hole is formed by pressing the plate 42 with the pressure foot 28 to form the hole. Vibration and lifting of the printed circuit board W at the time of drilling are prevented, and high-quality drilling is performed, and breakage of the drill 24 is also prevented. Each time the printed circuit board W is replaced, a new one is placed on this plate 42, and this plate 42 has to be disposable, which is uneconomical. The present invention has been made in view of the above-mentioned problems of the related art, and does not require the use of a plate placed on the uppermost part of a printed circuit board during drilling of the printed circuit board. A hole made by a PCB drilling machine that can always press the area near the drill hole on the PCB regardless of the size, and can more reliably drill the PCB without generating burrs on the PCB. It aims to provide a dawn method.

[Means for solving the problems]

In order to achieve the above object, the invention according to claim 1 is:
In a method of drilling a predetermined hole in a printed circuit board by lowering a drill while pressing a printed circuit board mounted on a table with a pressure foot, a printed circuit board is attached to a front end portion of the pressure foot. A state where the peripheral part of the printed circuit board is pressed by the piece when the hole is drilled in the printed circuit board for the first time, and the piece without the hole for the drill guide is detachably attached while holding the peripheral part of the drilled position. Drill a hole in the piece and the printed circuit board at the same time with a drill.In the second and subsequent drilling, hold the hole around the drilled position of the printed circuit board with the piece and use the drilled hole in the piece for drill guide. It is characterized in that it is used as a hole.

[Action]

Then, a piece is removably attached to the tip of the pressure foot, and one or a plurality of printed circuit boards are directly pressed by the piece, and a hole is drilled from above the piece. The piece attached to the tip of the pressure foot moves with the movement of the pressure foot.
That is, the pressure foot with the piece removably attached to the tip is lowered, and the printed circuit board placed on the table is directly pressed by the piece. Drill a hole. Thereafter, the piece is raised together with the pressure foot, and the next hole is formed by the same procedure. In this way, the piece is removably attached to the tip of the pressure foot, and the piece is directly pressed on the printed circuit board. Irrespective of the size of the drill diameter, it is possible to always press the periphery of the drilling position of the printed board, and to drill the printed board without generating burrs on the printed board.

【Example】

Hereinafter, examples of the present invention will be described. FIG. 1 and FIG. 2 show a first example of a printed circuit board drilling machine for performing a method for drilling by a printed circuit board drilling machine according to the present invention. In the figure, reference numeral 43 denotes a piece detachably provided at the tip of the pressure foot 23. This piece 43
Is press-fitted into a fitting portion 46 of the pressure foot 23 using a projection 44 of a part of the piece 43. The piece 43 has a conical portion 45 formed on the inside thereof, and the force of pressing the printed circuit board 15 by the air cylinder 22 is gathered around the drill 41 via the pressure foot 23. . A through hole (a hole for drill guide) 47 having a diameter substantially equal to the diameter of the drill 41 is formed substantially at the center of the piece 43 at a position coinciding with the axis of the drill 41. The drill 41 is slidably fitted into the through hole 47. Further, the printed board 15 is placed on the lower plate 16, and the uppermost end of the printed board 15 is not provided with the conventional plate 17 as in the related art. With this configuration, as shown in FIG. 2, when the spindle saddle 9 is lowered, the piece 43 attached to the tip of the pressure foot 23 presses the printed board 15 and presses the printed board 15. Therefore, this piece 43
Is a replacement for the conventional plate. With the piece 43 superimposed on the printed board 15 in this way, the drill 41 is lowered to process the printed board 15. In the present embodiment, the example in which the through hole formed substantially at the center of the piece 43 is formed in advance has been described, but the piece 43 is formed of a plastics molded product, and the printed circuit board is formed.
The drill 41 may be lowered while the piece 43 is superimposed on the piece 15, and the piece 43 and the printed circuit board 15 may be co-processed to form a through hole. That is, at the time of the first drilling, when the spindle saddle 9 is lowered, the piece 43 attached to the tip of the pressure foot 23 presses the printed board 15 and presses the printed board 15. Peace 43 in this state
Is a replacement for the conventional plate. In a state where the pieces 43 are superimposed on the printed circuit board 15 as described above, the pieces 43 and the printed circuit board 15 are co-processed by penetrating the pieces 43 and the printed circuit board 15 from above. At the time of the second and subsequent drilling, the drilling is successively performed by using the holes of the piece 43 drilled by co-processing as holes for the drill guide. FIGS. 3 and 4 show a second example of a printed circuit board drilling machine for performing the method for drilling by the printed circuit board drilling machine according to the present invention. In the figure, 49 is a piece storage device, and a table
Installed on 48. This piece storage device 49 holds a plurality of pieces 43 in a holder 50.
43 is pressed upward by a ring 51 and a spring 52. The uppermost piece 43A is, as shown in FIG.
The flange portion 55 of the piece 43A is supported by a stopper 53 that regulates upward movement from both sides and a guide 54 that guides the outer periphery of the flange portion 55 of the piece 43A. Reference numeral 56 denotes a projection provided at the tip of the pressure foot 23, and the uppermost piece from within the holder 50 of the piece storage device 49.
It is for paying out 43A. Reference numeral 57 denotes a piece positioning device, which has a U-shaped cross section.
And a spring 59 mounted inside the cushion stopper 58, and a holder 60 into which the cushion stopper 58 is slidably fitted. In such a configuration, now, the spindle saddle 9
Is lowered and the projection 56 provided on the pressure foot 23 pushes a part of the projection of the piece 43 in the direction shown by the arrow A in FIG.
Pay out from within. Thereafter, the dispensed top end piece 43 is guided by the guide 54 and slides on the table 48, and is pressed against a cushion stopper 58 having a built-in spring 59 for positioning. After the positioning, the spindle saddle 9 is further lowered, and the piece 43 is pressed into the fitting portion 46 of the pressure foot 23. FIG. 5 shows a third example of a printed circuit board drilling machine for performing the method for drilling by the printed circuit board drilling machine according to the present invention.
An example is shown. In the figure, 61 is a piece disposal device,
Installed on 48. The piece disposal device 61 includes a case 62 and a lid 63. A stopper is provided at the upper end of the case 62 similarly to the piece storage device 49 of FIG.
64 and a guide 65 are provided. The stopper 64 raises the pressure foot 23 upward, and
When removing the piece 43 from the piece 23, prevent the piece 43 from moving upward with the pressure foot 23.
Is pressed from both sides. guide
65 guides the outer circumference of the flange portion 55 so that the piece 43 fits smoothly into the stopper 64. In such a configuration, when the piece 43 pressed into the fitting portion 46 of the pressure foot 23 is to be discarded, as shown in FIG. It operates in the direction shown by arrow A in FIG.
Discard. FIG. 6 shows a fourth embodiment of a printed circuit board drilling machine for performing the method for drilling by the printed circuit board drilling machine according to the present invention.
An example is shown. In the figure, in this example, a piece storage device A, a piece temporary placement device B, and a piece disposal device C are incorporated in a table 48, respectively. In a printed circuit board drilling machine, it is usual to automatically change a drill by an automatic drill changing device (not shown) configured on the table 2. However, such a drill is temporarily replaced by replacing the drill. The piece temporary placement device is used when a piece needs to be removed. That is, in the case of temporary placement, the spindle saddle 9 has a stopper and a guide, and the spindle saddle 9 is in a state where neither the holder 50 of the piece storage device 49 shown in FIG. 3 nor the case 62 of the piece disposal device 61 shown in FIG. 5 operates in the direction indicated by the arrow A in FIG. Also, if the diameter of the drill to be used after the temporary placement is larger than the diameter of the previous drill, temporarily attach the previously used piece to the pressure foot 23 again,
The first hole can be used by being co-processed with the printed circuit board 15. The table 48 provided with each of the piece storage device A, the piece temporary placement device B, and the piece disposal device C may be the table 2 on which the printed circuit board 15 is placed. FIG. 7 shows a fifth embodiment of a printed circuit board drilling machine for performing the method for drilling by the printed circuit board drilling machine according to the present invention.
An example is shown. In the figure, 66 is a magnet built in the tip of the pressure foot 23. Reference numeral 67 denotes a magnetic body (for example, an iron piece) bonded to a plastic plate 68, and a piece 69 is formed by the magnetic body 67 and the plastic plate 68. If the vacuum suction means is provided at the distal end of the pressure foot 23, the piece constituted by the circular plate can be suctioned at a negative pressure. FIG. 8 shows a sixth embodiment of a printed circuit board drilling machine for performing the method for drilling by the printed circuit board drilling machine according to the present invention.
An example is shown. In FIG. 8, reference numeral 33 denotes a spindle body which rotatably supports a spindle therein. 34 is a chuck,
It is fixed to the spindle and holds the drill 24. Reference numeral 28 denotes a pressure foot, which is slidably fitted to the spindle body 33. A discharge port 38 for discharging air and chips in the pressure foot 28 is formed on a side surface of the pressure foot 28, and is connected to a dust collector (not shown) by a hose or the like. Also, pressure foot 28
As shown in FIG. 10, an annular passage 70 is provided from the center of the distal end surface of the pressure foot 28. The annular passage 70 has a gas suction passage having a predetermined length toward the outer peripheral side surface of the pressure foot 28. 71 is connected. A suction port 72 is connected to the gas suction passage 71. As shown in FIG. 10, a supply port 73 having a predetermined length is formed from the side surface of the pressure foot 28 at the tip end surface of the pressure foot 28. In the supply port 73, a gas supply passage 74 is formed with a predetermined length toward the center. As shown in FIG. 8, the gas supply passage 74 is formed in an L-shape toward the distal end surface of the pressure foot 28 and opens at the distal end surface of the pressure foot 28. Reference numeral 75 denotes a pad integrated with the pressure foot 28 by a fitting portion 76, as shown in FIG.
28, which is fixed to the lower surface. The pad 75 is provided with a plurality of cavities 77 connected to the gas suction passage 71 and having a predetermined length radially. An annular passage 78 is provided from the center of the pad 75 as shown in FIG.
Is connected to a passage 79 having a predetermined length toward the outer peripheral surface of the pad 75. An orifice-shaped nozzle 80 is provided in the passage 79. The annular passage 70, the gas suction passage 71, and the cavity
An air suction path is constituted by the air passage 77 and the air suction passage 77. The gas supply passage 74, the annular passage 78, and the passage 79 form an air supply passage. Reference numeral 81 denotes an air outlet opening toward the inside of the lower end portion of the pressure foot 28. The air outlet 81 is blown toward the drill 24 in the direction along the drill groove as shown in FIG. It is cut like so. On the other hand, reference numeral 82 denotes a flow-regulated high-pressure air supply device for supplying high-pressure air to a supply port 73. 83 is a cylinder of the spindle housing 35, 84 is a piston of the pressure foot 28, and 85 is a cylinder air supply pipe. When air 86 is supplied, the pressure of the cavity 87 increases, and the pressure foot 28 is pressed in the arrow Z direction. I do. Reference numeral 88 denotes a low-pressure generator for sucking air from the cavity 77. Reference numeral 89 denotes a plate-like member, which is attached to the lower surface of the pad 75. When the low-pressure generating air 88, which is compressed air, is sent to the low-pressure generating device 88, an annular passage 70, a gas suction passage 71, and a cavity are formed by a suction effect.
The gas in 77 flows in the direction shown by the arrow in FIG.
When the plate-like member 89 is applied in this state, the pressure in the annular passage 70, the gas suction passage 71, and the inside of the cavity 77 is reduced, and this is adsorbed. In this way, the plate-like member 89 is attached to the lower surface of the pad 75 attached to the tip of the pressure foot 28. The cavity 77 is for adsorbing the plate-like member 89 over an area as large as possible to increase the attraction force, and 91 is a case where the external shape of the plate-like member 89 is fitted and some external force is applied to the plate-like member 89. However, it is a guide to avoid slippage. When removing chips during drilling and cooling the drill, high-pressure air (compressed air) is adjusted to a predetermined amount by a flow-adjustable high-pressure air supply device 82 and supplied to a supply port 73. It is guided to a nozzle 80 through 78 and 79, is adiabatically expanded by the nozzle 80, is cooled down in a passage 78, and is further cooled by an air outlet 81 to the drill 24 from the drill tip direction along the drill groove as shown in FIG. The drill 24 is cooled by being blown in the same direction, and chips are removed. The air in the pressure foot 28 is vacuumed from the outlet 38. For this reason, the chips removed from the tip of the drill 24 are introduced into the pressure foot 28 by the compressed air blown out from the air outlet 81, and the pressure foot 28
The air is discharged from the outlet 38 together with the compressed air blown out from the air outlet 81 introduced therein. Reference numerals 92 and 93 denote O-rings for preventing air leakage. Reference numeral 94 denotes a hole in the printed circuit board 95 that has been drilled, and reference numeral 96 denotes a lower plate on which the printed circuit board 95 is placed. With such a configuration, the low-pressure generating
When 90 is sent, the annular passage 70 is created by the suction effect
Then, the gas in the gas suction passage 71 and the cavity 77 flows in the direction shown by the arrow in FIG. In this state, the plate member
When 89 is applied to the lower surface of the pad 75, the pressure in the annular passage 70, the gas suction passage 71, and the inside of the cavity 77 is reduced, and this is adsorbed. Then, the inside of the pressure foot 28 is cut off from the outside air by the pressure foot 28 and the plate-like member 89, and a negative pressure is generated. Therefore, the compressed air supplied from the supply port 73 is guided to the nozzle 80 through the gas supply passage 74 and the passage 79, is adiabatically expanded by the nozzle 80, is cooled down in the passage 78, and is further drilled by the air outlet 81. As shown in FIG. 11, the nozzle 24 is blown from the direction of the drill tip along the drill groove, and rapidly expands inside the air outlet 81 and the pressure foot 28. When the compressed air is blown out from the air outlet 81 as shown by the arrow C in FIG. 9, the air flow shown by the arrow C → arrow D → arrow E in FIG.
Exhaust is performed. When the spindle body 33 is lowered in this state, first, the plate-like member 89 adsorbed on the lower surface of the pad 75 attached to the distal end surface of the pressure foot 28 contacts the uppermost stage of the printed board 95, and Is pressed via the plate member 89. Further, when the spindle body 33 is lowered, the drill 24 is pushed into the printed circuit board 95 as shown in FIG.
A hole 94 is formed in the printed board 95 from above the plate member 89. At this time, the air blown out from the air outlet 81 flows as shown by arrow C → arrow D → arrow E in FIG.
Cool 24. Then, when the spindle body 33 rises, the drill 24
From the printed circuit board 95 and the plate-like member 89. At this time, since air is flowing as indicated by arrows C, D, and E in FIG.
It is eliminated by the airflow indicated by arrows C, D, and E in the drawing. At the same time, the drill 24 is cooled because the cooled air hits the drill 24. As described above, the hole (drill guide hole) 94 formed in the plate member 89 by the drill 24 is used in the next drilling (2).
The drill 24 will be guided during the subsequent drilling). Therefore, by using this plate-like member 89, the periphery of the printed board 95 at the perforated position can always be held down in the same state. FIGS. 12 to 17 show the plate-like member 89 when the drill 24 is attached and detached.
A series of operations are shown for the supply and disposal of. That is, FIG. 12 shows a standby state in which the drill 24 is not chucked to the spindle. FIG. 13 shows a state in which a drill is attached to chuck the drill 24 on the spindle. Further, FIG. 14 shows that the low-pressure generating device 88 is operated, the low-pressure generating air 88 is sent to the low-pressure generating device 88, and an annular passage 70, a gas suction passage 71, and a cavity are formed by a suction effect.
In this state, the gas in 77 is sucked, the plate-like member 89 is applied to the lower surface of the pad 75, and the plate-like member for absorbing this is attached.
Reference numeral 97 denotes a plate-like member stocker for storing a plurality of plate-like members 89. Reference numeral 98 denotes a plate-like member lifting device, which has a function of pushing up the plate-like member 89 in a direction indicated by an arrow. Reference numeral 99 denotes a plate-like member pushing device, which pushes the plate-like member 89 out of the plate-like member stocker 97, slides on the supply table, and moves to the plate-like member standby position 100. The pressure foot 28 is moved in the Z-axis direction as shown by the arrow to attract the plate-like member 89. FIG. 15 shows a drilling state in which the spindle body 33 is lowered, the drill 24 is pushed into the printed circuit board 95, and a hole 94 is formed in the printed circuit board 95 from above the plate-like member 89. Further, FIG. 16 shows that the spindle body 33 is raised, the drill 24 is extracted from the printed circuit board 95 and the plate-like member 89, and the low pressure generating air 90, which is compressed air sent to the low pressure generating device 88, is not removed. Passage 70 and a gas suction passage 71
And a plate-like member 89 which is supplied to the cavity 77, generates a high pressure in the cavity 77, and is applied to the lower surface of the pad 75.
This is a plate member discarded state in which the sheet member is peeled off and discarded. 102 is
This is a disposal station for the used plate member 89. When the valve 103 of the low-pressure generating device 88 is pushed in the direction shown by the arrow A and the flow of the low-pressure generating air 90 is switched, the low-pressure generating Annular passage 70 by air 90
Then, the pressure in the gas suction passage 71 and the inside of the cavity 77 is increased, and by increasing the pressure, the plate member 89 is separated and discarded. FIG. 17 shows a standby state in which the drill 24 is not chucked to the spindle 21 as in FIG. The direction of the compressed air blown out from the air outlet 81 may be blown toward the rotation center of the drill 24. Therefore, according to this embodiment, a small piece of the conventional plate material can be easily attached to and detached from the pressure foot of the printed circuit board drilling machine, and it is not necessary to use a plate having the same size as the printed circuit board. Further, according to the present embodiment, a hole quality equal to or higher than the conventional drill life can be obtained by processing the required plate of φ0.2 mm or more. Since the present invention is configured as described above,
The following effects are obtained. Even without using a plate to be placed on the top of the printed circuit board during drilling of the printed circuit board, it is possible to always hold the area around the drilled position of the printed circuit board regardless of the diameter of the drill, and it is possible to flash the printed circuit board. Drilling of the printed circuit board can be performed more reliably without generating the problem. Further, since the piece and the printed board are co-processed, when the drill is changed from a small diameter to a large diameter, the piece can be used again, which is economical.

[Brief description of the drawings]

1 and 2 are side sectional views showing a first example of a printed circuit board drilling machine for performing a method for drilling by a printed circuit board drilling machine according to the present invention, and FIG. 3 is a print according to the present invention. FIG. 4 is a side sectional view showing a second example of a printed circuit board drilling machine for performing a drilling method using a substrate drilling machine, FIG. 4 is a plan view of a piece storage device shown in FIG. 3, and FIG. FIG. 6 is a side cross-sectional view showing a third example of a printed circuit board drilling machine for performing the drilling method using the printed circuit board drilling machine. FIG. FIG. 7 is a plan view of a table showing a fourth example of a printed circuit board drilling machine for drilling, and FIG. 7 is a fifth example of a printed circuit board drilling machine for performing a method of drilling by the printed circuit board drilling machine according to the present invention. FIG. 8 is a side sectional view of a printed circuit board drilling machine according to the present invention. FIG. 9 is a side sectional view of a pressure foot showing a sixth example of a printed circuit board drilling machine for carrying out a drilling method, FIG. 9 is an explanatory view of the operation of the pressure foot, and FIG. Bottom view of pressure foot,
FIG. 11 is an enlarged bottom view of the drill shown in FIG. 8 showing the relationship between the drill and the air flow, FIGS. 12 to 17 are diagrams showing the operation procedure of the printed circuit board drilling machine shown in FIG. 8, and FIG. FIG. 19 is a perspective view of a printed circuit board drilling machine, FIG. 19 is a cross-sectional side view of a spindle section of a conventional printed circuit board drilling machine, FIG. 20 is a side sectional view of another spindle section of the conventional printed circuit board drilling machine, FIG. 21 is a side sectional view showing a state in which a large-diameter drill is chucked to the spindle of the printed circuit board drilling machine shown in FIG. 19, and FIG. 22 is a small-diameter drill attached to the spindle of the printed circuit board drilling machine shown in FIG. 23 is a side sectional view of the spindle portion of the printed circuit board drilling machine shown in FIG. 20, and FIG. 24 is an operation of the pressure foot of the printed circuit board drilling machine shown in FIG. 20. FIG. 1 ... PC board drilling machine 2,48 ... Table 15,95 ... PC board 21 ... Spindle 22 ... Air cylinder 23,28 ... Pressure foot 24,41 ... Drill 38 ... Exhaust port 43, 69… piece 47,94… Drill guide hole 49… piece storage device 61… piece disposal device 67… magnetic material 70,78,79… passage 71… gas suction passage 72… suction port 73 Supply port 74 Gas supply passage 75 Pad 77 Cavity 81 Air outlet 82 High-pressure air supply device 88 Low-pressure generation device 89 Plate member 95 Hole

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-95806 (JP, A) JP-A-63-17711 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B23B 41/00 B23B 35/00

Claims (1)

(57) [Claims] 1. A method of drilling a printed circuit board mounted on a table by lowering a drill while pressing the printed circuit board by a pressure foot, and drilling a predetermined hole in the printed circuit board using the pressure foot. At the tip of the printed circuit board, a piece without a hole for a drill guide is detachably attached while holding the periphery of the hole of the printed circuit board, and the piece is used to make a hole in the printed circuit board for the first time. A hole is drilled in the piece and the printed circuit board at the same time by the above-mentioned drill with the peripheral part of the drilled position being pressed. In the second and subsequent drilling, the state where the peripheral part of the drilled position of the printed circuit board is pressed by the piece is described. Wherein a hole drilled in said piece is used as a hole for a drill guide.