JP2006123027A - Pressure foot for printed board drilling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve accuracy and quality of drilling by bringing an entry board into pressure contact with the surface of a printed board without a clearance irrespective of the surface flatness of the printed board in drilling the printed board. <P>SOLUTION: A resilient rubber ring 26 is mounted to the lower face center of a pressure foot 22 for a printed board drilling device, and the entry board 12 is pressed through the rubber ring. The entry board on the printed board can thereby stick closely to the surface of the printed board irrespective of the surface flatness of the printed board 11 to eliminate a possibility of forming burrs around a drilled hole, or damaging the surface of the board due to chip entering between the entry board and the printed board. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pressure foot of a printed circuit board drilling device, and in particular, a thick component such as a multilayer flexible printed circuit board or a rigid flexible printed circuit board in which a rigid printed circuit board and a flexible printed circuit board are combined. The present invention relates to drilling a printed circuit board having a mounting portion and a thin cable portion.

  A printed circuit board used in an electronic device is provided with a through hole for the purpose of conduction between laminated circuit layers. The hole processing for this is usually performed by a printed circuit board hole processing apparatus equipped with a drill.

  4 shows a drill unit 1 of a printed circuit board drilling device, 2 is a pressure foot made of a metal material for pressing the printed circuit board from above, 3 is a spindle driven by a motor (not shown), and the spindle A drill bit 4 is mounted at the center of the tip of 3.

  When drilling a printed circuit board, multiple printed circuit boards 11 are stacked, and the printed circuit board 11 is sandwiched from above and below by the entry board 12 and the backup board 13 and set on a work table (not shown) of the printed circuit board drilling device. To do.

  By the drilling start operation, the drill unit 1 is lowered and the pressure foot 2 hits the entry board 12, and the pressure foot 2 biased downward by a spring mechanism (not shown) is moved between the entry board 12 and the printed board 11. Press the laminate. In a state where the pressure foot 2 hits the entry board 12 and stops descending, the spindle 3 further descends, and a hole is processed in the printed board 11 by the drill bit 4.

  The entry board 12 is used to protect the substrate surface during drilling and to suppress hole burrs. Usually, a 0.4 to 0.8 mm bakelite plate or a 0.15 to 0.2 mm aluminum plate is used. The pressure foot 2 is pressed to eliminate the gap between the printed circuit board 11 and the entry board 12. If there is a gap between the printed circuit board 11 and the entry board 12, a hole burr is generated or chips are generated in the gap. This may cause indentation on the printed circuit board.

  In the drilling of a printed circuit board having a thick component mounting portion and a thin cable portion, such as a multilayer printed wiring board or a rigid flexible printed wiring board, an inner layer portion including a cable portion is generally formed and an outer layer is formed. A part corresponding to the cable part is punched out in the component mounting part to be a part, and then adhered and laminated to the inner layer part via a laminating adhesive. At this time, the laminated adhesive flows out from the edge of the component mounting portion of the outer layer to the cable portion, and the component mounting portion of the bonded semi-finished product tends to have a slightly thinner edge portion than the central portion. That is, the cross section of the component mounting portion often has a slight convex shape.

  In this case, when the pressure foot 2 presses against the entry board 12 as shown in FIG. 5, the pressure foot 2 may bring the entry board 12 into close contact with the printed circuit board 11 near the boundary between the cable portion 11b and the component mounting portion 11a. As a result, a gap is generated between the component mounting portion 11a and the entry board 12, and a hole burr is generated, or a cut mark enters the gap, resulting in a scratch on the printed board 11.

  As a method for suppressing the gap between the board and the entry board, for example, there is a bush exchange system that selects a bush having a drill insertion hole according to a drill diameter via a detachable bush having a drill insertion hole at the lower part of the pressure foot. It has been proposed (Patent Document 1).

  In addition, a mechanism has been proposed in which a turret-shaped substrate pressing piece in which a plurality of drill insertion holes having different hole diameters are radially arranged is rotated to select a drill insertion hole according to the drill diameter (Patent Document 2).

  In addition, a pressure foot has been proposed in which the lower part of the bush for holding the substrate is made of a plastic material and the aluminum plate used for the entry board is prevented from being damaged when the pressure foot is moved (Patent Document 3).

However, these proposals are a means to improve the drilling accuracy and dust collection efficiency by reducing the gap between the drill outer periphery and the drill insertion hole of the board pressing part as much as possible to suppress the entry board from rising. Documents 1 and 2) and means for preventing scratches on the entry board (Patent Document 3), and in the case where the printed circuit board is inclined as shown in FIG. 5, it is not possible to suppress the gap between the board and the entry board. Can not.
Japanese Patent Laid-Open No. 5-285891 JP 2000-334697 Japanese Unexamined Patent Publication No. 8-15597

  As described above, a printed circuit board having a thick component mounting portion and a thin cable portion tends to be thinner at the edge of the component mounting portion than the center portion. When the pressure foot of the processing apparatus presses the entry board, a gap may be formed between the edge of the component mounting part and the entry board, resulting in hole burrs, or damage to the printed circuit board.

  Therefore, regardless of the flatness of the surface of the printed circuit board, there is a technical problem to be solved in order to improve the accuracy and quality of drilling so that the entry board can be pressed against the surface of the printed circuit board without gaps. The present invention aims to solve the above problems.

  The present invention is proposed to achieve the above object, and includes a drill for drilling a workpiece on the work table, and a pressure foot for pressing the periphery of the drilled portion of the workpiece to the work table from above. In the printed board hole processing apparatus, a pressure is applied to the printed board hole processing apparatus, wherein a rubber ring having a drill insertion hole is attached to the center of the lower end of the pressure foot, and the workpiece is pressed through the rubber ring. It provides a foot.

  Further, the present invention provides a pressure foot for a printed circuit board hole processing apparatus in which the rubber ring can be freely attached to and detached from the pressure foot of the printed circuit board hole processing apparatus and can be replaced with a rubber ring having a different drill insertion hole diameter. .

  Further, the present invention provides a pressure foot for a printed circuit board hole processing apparatus in which fitting means such as a groove and a rib or a concave portion and a convex portion are provided on the pressure foot and the rubber ring.

  Further, the present invention provides a pressure foot for a printed circuit board hole processing apparatus in which embossing or a groove is processed on the lower surface of the rubber ring to prevent the rubber ring and a workpiece from sticking to each other.

  By attaching a rubber ring with elasticity to the lower part of the pressure foot and pressing the work piece through the rubber ring, the entry board placed on the printed board can be printed regardless of the flatness of the surface of the printed board. It can be brought into close contact with the surface of the substrate, and there is no gap between the printed circuit board and the entry board.

  The pressure foot of the printed circuit board hole processing apparatus of the present invention is equipped with a rubber ring at the center of the lower end so that an entry board is placed on a thick component mounting portion such as a multilayer flexible printed circuit board or a flex-rigid printed circuit board. In this case, even when the surface of the component mounting portion is not flat and the edge portion is inclined, the entry board can be brought into close contact with the component mounting portion. This eliminates the possibility of burrs around the holes and the possibility of chips entering between the entry board and the component mounting part and scratching the surface of the board, improving the accuracy and quality of hole processing. Play.

  This invention is configured to attach a rubber ring to the center of the lower end of the pressure foot of the printed circuit board hole processing apparatus and press the workpiece through the rubber ring, regardless of the flatness of the surface of the printed circuit board, The entry board can be pressed against the surface of the printed circuit board without any gaps, and there is a risk that burrs will form around the hole or chips will enter between the entry board and the component mounting area, causing damage to the surface of the board. Was solved.

  FIG. 1 shows a drill unit 21 of a printed circuit board drilling device, 22 is a pressure foot, 23 is a spindle driven by a motor (not shown), and a drill bit 24 is attached to the center of the tip of the spindle 23. Yes.

  The pressure foot 22 is attached to the drill unit 21 body through a vertical slide guide 25 fixed to the outer peripheral portion, and is biased downward by a spring (not shown), and when the drill unit 21 is lowered, First, the pressure foot 22 is pressed against the surface of the entry board 12, the spindle 23 and the drill bit 24 are further lowered, and the drill bit 24 is drilled in the printed board 11 through the center hole of the pressure foot 22.

  A small-diameter cylindrical portion 22a is formed in the center of the lower end of the pressure foot 22, and a rubber ring 26 is wound around the cylindrical portion 22a. The length (vertical length) of the rubber ring 26 is larger than the length of the cylindrical portion 22a, and only the rubber ring 26 contacts the surface of the entry board 12 when the pressure foot 22 is lowered. When the pressure foot 22 comes into pressure contact with the entry board 12, the rubber ring 26 deforms following the surface of the entry board 12, and the entire lower end surface of the rubber ring 26 contacts the entry board 12 and presses the entry board 12.

  Examples of the material of the rubber ring 26 include nitrile rubber, acrylic rubber, fluorine rubber, and urethane rubber. The hardness of the rubber material is recommended to be 60 to 90 in terms of JIS Hs hardness. If the printed circuit board 11 has a relatively large number of cable parts 11b and inclined component mounting parts 11a, use a softer one, and if there are few inclined parts, use a harder one. It is even better if you do.

  As described above, the printed board 11 has an inclined shape in which the thickness of the edge of the component mounting portion 11a is slightly thinner than the center due to the outflow of the adhesive, and the surface is slightly lowered toward the edge. There is a gap between the edge of the surface of the component mounting portion 11a and the entry board 12 and the backup board 13.

  FIG. 2 shows a state in which the drill unit 21 is lowered from the initial state of FIG. 1.When the pressure foot 22 is lowered and the rubber ring 26 is pressed against the entry board 12, the rubber ring 26 is elastically deformed by the pressure, The entry board 12 is deformed along the inclined surface of the component mounting portion 11a of the printed circuit board 11, and is brought into pressure contact with the entire surface of the component mounting portion 11a without any gap. As a result, when the drill bit 24 drills the printed circuit board 11, burrs are not generated, and chips do not enter between the component mounting part 11a and the entry board 12, so that high precision and high quality can be achieved. Holes can be formed.

  FIG. 3 shows another embodiment of the rubber ring 26. In (a), a groove 22b is formed on the lower outer peripheral surface of the pressure foot 22, and the rubber ring 26 has a portion corresponding to the groove 22b of the pressure foot 22. A rib 26a is provided to form a mating pair, and the rubber ring 26 is securely fixed to the pressure foot 22.

  (b) shows an example in which a rib 22c is provided on the outer peripheral surface of the lower part of the pressure foot 22 and a groove 26b corresponding to the rib 22c is provided on the inner peripheral surface of the rubber ring 26 and fixed, contrary to (a). Yes.

  Further, as shown in (c), a groove 22d is formed on the horizontal bottom surface around the small diameter portion of the lower end of the pressure foot 22, and a rib 26c having a shape corresponding to the groove 22d is provided on the upper end surface of the rubber ring 26. Alternatively, the pressure foot 22 may be coupled.

  By doing so, the rubber ring 26 is detachable and securely fixed to the pressure foot 22, and can be easily replaced with a rubber ring having a different material or hole diameter when worn.

  Also, if the rubber ring sticks closely to the entry board, it will hinder the transition to the next process.Therefore, as shown in (a) (b) (c), a groove is formed in the bottom of the rubber ring 26. It is preferable to prevent sticking by cutting 26d or embossing.

  The present invention is not limited to the above-described embodiment, and various modifications are possible within the technical scope of the present invention. For example, the present invention can be attached to and detached from the pressure foot described in Patent Document 1 as a conventional example. A rubber ring may be attached to the lower part of the bush, or a plurality of rubber rings with different hole diameters may be attached to the turret-shaped substrate holding piece of the pressure foot described in Patent Document 2. It is natural to cover what has been done.

Sectional drawing of the pressure foot part of the printed circuit board hole processing apparatus which shows one Example of this invention. Sectional drawing which shows the entry board press state of the pressure foot of FIG. (a) (b) (c) is sectional drawing which shows other embodiment of a pressure foot, respectively. Sectional drawing which shows a prior art example and shows the entry board press state of a pressure foot. Sectional drawing which shows a prior art example and shows the entry board press state of a pressure foot.

Explanation of symbols

11 Printed circuit board
11a Component mounting part
11b Cable part
12 entry board
13 Backup board
21 Drill unit
22 Pressure foot
22a Tube
22b groove
22c rib
22d groove
23 spindle
24 drill bits
25 Slide guide
26 Rubber ring
26a rib
26b groove
26c rib
26d groove

Claims (4)

  In a printed circuit board hole processing apparatus comprising a drill for drilling a workpiece on a work table and a pressure foot for pressing the periphery of the drilled portion of the workpiece from above to the work table, the rubber ring having a drill insertion hole A pressure foot for a printed circuit board hole processing apparatus, wherein the pressure foot is attached to a center of a lower end of the pressure foot and presses a workpiece through the rubber ring.   The pressure foot of a printed circuit board hole machining apparatus according to claim 1, wherein the rubber ring is detachable from the pressure foot of the printed circuit board hole machining apparatus, and can be replaced with a rubber ring having a different drill insertion hole diameter.   2. The pressure foot of a printed circuit board hole machining apparatus according to claim 1, wherein fitting means such as a groove and a rib or a concave portion and a convex portion are provided on the pressure foot and the rubber ring. 2. A pressure foot for a printed circuit board hole machining apparatus according to claim 1, wherein an emboss or a groove is formed on the lower surface of the rubber ring to prevent the rubber ring and the workpiece from sticking to each other.

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