JP2008034804A - Print wiring board, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a print wiring board capable of suppressing a fracture of a drilling edge and excellent in bore position accuracy. <P>SOLUTION: There is provided a manufacturing method of a print wiring board for drilling by using a bush 6 for drilling formed with an opening hole 12 through which a drilling blade 8 with diameter (ϕ) of 0.45 mm or less is passed, and formed on a pressing surface for pressing a print wiring board 3 which is subjected to drilling by the drilling blade in a peripheral edge of the opening hole. The ratio of an inner diameter of the opening hole to the diameter of the drilling blade is 4 to 7, and a bush for drilling is used, which is provided with a groove formed narrowly on the pressing surface in a rotation direction of the drilling blade toward the opening hole from the periphery of the opening hole. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a printed wiring board and a manufacturing method thereof.

  In recent years, with increasing functionality of electronic devices, printed wiring boards are also strongly required to improve wiring density. In order to cope with this, in the printed wiring board that has been drilled, it is essential to improve the hole density.

  In the drilling step of the printed wiring board manufacturing method, it is desired to reduce the inner wall roughness and to secure the positional accuracy of the holes to be formed. When drilling a printed wiring board, drilling has been performed using a drill as shown in Patent Document 1.

  In addition, when drilling a printed wiring board, it is very effective for the bush mounted on the drilling machine to ensure the hole position accuracy by reducing the diameter of the opening hole through which the drill passes during cutting. However, only by reducing the diameter of the opening hole through which the bushing drill passes, if the suction air amount is insufficient or the angle of air blowing to the drill at the time of suction is inappropriate, breakage of the drill or displacement of the hole position occurs.

In drilling with a drill, high hole position accuracy is required to ensure the insulation distance between the hole and the pattern. Particularly, drilling using a small diameter drill with a diameter (φ) of 0.45 mm or less is an important issue. Come.
JP 2005-118923 A

  An object of the present invention is to provide a printed wiring board manufacturing method that suppresses occurrence of breakage of a drill blade even when a small-diameter drill is used and has excellent hole position accuracy, and a printed wiring board manufactured by the manufacturing method. It is what.

  According to the present invention, (1) an opening hole through which a drill blade having a diameter (φ) of 0.45 mm or less passes is formed, and a peripheral surface of the opening hole is formed on a pressing surface that holds a printed wiring board drilled by the drill blade. A printed wiring board manufacturing method for drilling using a drilling bush formed with a portion, wherein the ratio of the inner diameter of the opening hole to the diameter of the drill blade is 4-7, A printed wiring board, wherein drilling is performed using a drilling bush provided with a groove formed narrowly in the rotation direction of the drill blade from the periphery of the opening hole toward the opening hole It relates to the manufacturing method.

  In the present invention, (2) an opening hole through which a drill blade having a diameter (φ) of 0.45 mm or less passes is formed, and the opening hole is formed on a pressing surface that holds a printed wiring board drilled by the drill blade. Is a printed wiring board manufacturing method for drilling using a drilling bush having a peripheral edge portion formed therein, wherein the inner diameter of the opening hole is 1.8 mm to 2.1 mm, A printed wiring board characterized in that drilling is performed using a drilling bush provided with a narrow groove formed in the rotation direction of the drill blade from the periphery of the opening hole toward the opening hole. It relates to a manufacturing method.

  The present invention also relates to (3) a printed wiring board manufactured by the method for manufacturing a printed wiring board according to (1) or (2).

  ADVANTAGE OF THE INVENTION According to this invention, even when a small diameter drill is used, there is little breakage of a drill blade, and the printed wiring board excellent in the hole position accuracy and its manufacturing method can be provided.

  In the method for producing a printed wiring board of the present invention, an opening hole through which a drill blade having a diameter of 0.45 mm (φ) or less passes is formed, and the pressing surface for pressing the printed wiring board to be drilled by the drill blade is A printed wiring board manufacturing method for drilling using a drilling bush having a peripheral edge of an opening hole, wherein the ratio of the inner diameter of the opening hole to the diameter of the drill blade is 4-7, Drilling is performed using a drilling bush provided on the pressing surface from the periphery of the opening hole toward the opening hole, with a groove formed narrowly in the rotation direction of the drill blade. To do.

  Further, the printed wiring board manufacturing method of the present invention has an opening hole through which a drill blade having a diameter (φ) of 0.45 mm or less passes, and is provided on a pressing surface for pressing the printed wiring board to be drilled by the drill blade. A method of manufacturing a printed wiring board for drilling using a drilling bush in which a peripheral portion of the opening hole is formed, wherein an inner diameter of the opening hole is 1.8 mm to 2.1 mm, and the pressing Drilling is performed using a drilling bush provided on a surface with a groove formed narrowly in the rotation direction of the drill blade from the periphery of the opening hole toward the opening hole. .

The present invention will be described below with reference to the drawings. FIG. 1 is a view showing a use state of a drilling bush. As shown in FIG. 1, the printed wiring board 3 is drilled with a drill 8, as shown in FIG. 1, first, the printed wiring boards are laminated as desired, and are sandwiched and fixed between the upper backing plate 5 and the lower backing plate 4. The bush 6 is attached to a lower end portion of a pressure shift 9 provided so as to be capable of raising and lowering, and the bush 6 is lowered along with the pressure shift 9 so that the printed wiring board 3 placed on the lower plate 4 is placed. Is pressed through the top plate 5. Then, the drill 8 is lowered, and the printed wiring board 3 is drilled by the drill blade 11 that has passed through the opening hole 12.
Although the printed wiring board 3 is not particularly limited, for example, as shown in FIG. 2, a predetermined number of copper-clad laminates 1 and prepregs 2 are laminated and formed by heating and pressing to be integrated.
The diameter (φ) of the drill blade 11 supported by the drill 8 used in the manufacturing method of the present invention is 0.45 mm or less, preferably 0.3 mm or less, more preferably 0.1 mm to 0.3 mm. It is. When the diameter (φ) of the drill blade 11 exceeds 0.45 mm, the drill blade is broken or the hole position accuracy is poor.

  An opening hole 12 through which the drill blade 11 passes is formed in the central portion of the bush 6. The inner diameter of the opening hole 12 (portion indicated by reference numeral 10 in FIG. 3) is 4 to 7 times the diameter of the drill blade. It is preferably 4 to 5 times for a drill blade having a diameter of 0.45 mm, and preferably 6 to 7 times for a drill blade having a diameter of 0.3 mm. By making the ratio of the inner diameter of the opening hole to the diameter of the drill blade 4 to 7 times, the occurrence of breakage of the drill blade can be suppressed and the hole position accuracy can be further improved.

  Moreover, the internal diameter of an opening hole is 1.8 mm-2.1 mm. When the inner diameter of the opening hole is less than 1.8 mm, the drill blade breaks, and when it exceeds 2.1 mm, the drill blade breaks or the hole position accuracy is poor.

A protrusion 7 that protrudes toward the printed wiring board 3 is formed at the center of the bush 6. The protrusion 7 has a pressing surface 13 that holds the printed wiring board 3. The form of the pressing surface will be further described with reference to FIG. FIG. 3 is a schematic view of the bush shape, and is an explanatory view seen from the printed wiring board side to be drilled. A plurality of groove portions 14 are formed in the projecting portion 7. For example, in FIG. 3, six groove portions 14 are formed. The groove 14 is formed to be recessed with respect to the pressing surface 13. The groove portion 14 is formed in a tapered shape so as to become narrower from the periphery of the opening hole 12 toward the opening hole 12 toward the rotation direction of the drill blade 11 indicated by the arrow in the drawing. Thereby, the protrusion part 7 is formed in the fan shape of an air fan.
By forming the groove 14 from the periphery of the opening hole 12 toward the opening hole 12 in the same direction as the rotation direction of the drill blade 11, breakage of the drill blade 11 during cutting can be prevented, and further, when the drill enters Therefore, the hole position accuracy on the punching surface side can be improved. Further, the outside air can be efficiently sucked using the flow of spiral air generated around the drill blade 11 as the drill blade 11 rotates.

  Further, by forming the groove portion 14 in a tapered shape so as to become narrower from the periphery of the opening hole 12 toward the opening hole 12, the peripheral portion of the drilled portion can be suppressed more firmly, and the hole position accuracy is improved. can do. Further, a large amount of air can be introduced in the peripheral portion where the groove width is wide, and the air introduced into the groove portion 14 increases in wind speed and proceeds toward the opening hole 12 as the groove width decreases. The swarf generated between the two can be removed by blowing off at a high wind speed.

  Hereinafter, the reference numerals in the examples and comparative examples are those described in FIGS.

  The printed wiring board 3 is a copper clad laminate 1 having an insulating layer in which a glass cloth is impregnated with an epoxy resin having a thickness of 0.1 mm and a copper foil thickness of 35 μm (manufactured by Hitachi Chemical Co., Ltd., trade name MCL- E-679) and prepreg 2 (trade name GIA-671N, manufactured by Hitachi Chemical Co., Ltd.) impregnated with a glass cloth with a modified polyimide resin are heated and pressurized to be laminated and integrated. A 16-layer product of 3 mm was obtained.

  The printed wiring board 3 is punched by overlaying two printed wiring boards 3 and adding a 0.16 mm water-soluble lubricant to the aluminum surface (Mitsubishi Gas Chemical Co., Ltd., trade name LE812F3). 5 and the lower plate 4 of the phenolic resin substrate were fixed and sandwiched and set on a perforated table.

As the drilling conditions, drilling was performed using a drill 8 having a diameter of the drill blade 11 of 0.30 mm to 0.50 mm under conditions of a spindle rotation speed of 100 Kmin ⁻¹ and a feed speed of 2.0 m / min. At this time, the form of the bush 6 used was nine kinds, 2000 holes were drilled per drill blade, and the bush was replaced every 10 drill blades.

  In the drilling, the pressure foot 9 on the machine side where the bush 6 is mounted descends and the printed wiring board 3 is held down, then a hole is drilled in a predetermined position, and then the pressure foot 9 rises and repeats this movement. Will dawn. After all the bushes 6 were drilled, the printed wiring board 3 was removed from the drilling table and disassembled, and used with a hole analyzer (trade name HA-1 manufactured by Hitachi Via Mechanics Co., Ltd.) which is an automatic hole position measuring machine. For each bush, the amount of hole position deviation between the drill entry surface side and the drill exit surface side (plate thickness 4.6 mm) of the printed wiring board 3 was measured. For the measurement of the hole position deviation amount, measure the distance between the center coordinate of the drilling design position and the center coordinate of the actually drilled hole position with a hole analyzer, and determine the maximum value of the hole position deviation amount and the hole position deviation amount. A value of average + 3σ was calculated for each of the drill entrance surface side and the drill exit surface side. The evaluation result is judged as Good if there is no breakage of the drill blade and the maximum value of the hole position deviation amount is less than 45 μm on both the drill entry surface side and the drill exit surface side. NG was defined as one having a maximum hole position deviation amount of 45 μm or more on either the drill entry surface side or the drill exit surface side. Tables 1 and 2 show the results of studying different combinations of drill blade diameters and bushings.

(Example 1) A drill having a blade diameter (φ) of 0.45 mm and a groove having a narrow groove formed in the rotation direction of the drill blade, and a bush having an inner diameter of 1.8 mm in the opening hole were combined.

(Example 2) A drill having a blade diameter (φ) of 0.45 mm and a groove having a narrow groove formed in the rotation direction of the drill blade, and a bush having an inner diameter of 2.1 mm in the opening hole were combined.

(Example 3) A drill having a blade diameter (φ) of 0.3 mm and a bush having a narrow groove formed in the rotation direction of the drill blade and having an opening hole with an inner diameter of 1.8 mm were combined.

(Example 4) A drill having a blade diameter (φ) of 0.3 mm and a bush having a narrow groove formed in the rotation direction of the drill blade and having an inner diameter of 2.1 mm in the opening hole were combined.

(Comparative Example 1) A drill having a blade diameter (φ) of 0.45 mm was combined with a bush having a groove portion formed with an equal width in the center direction from the periphery of the opening hole, and a bush having an inner diameter of 3 mm.

(Comparative Example 2) A drill having a blade diameter (φ) of 0.45 mm and a groove portion having an equal width opposite to the rotation direction of the drill blade and a bush having an inner diameter of 3 mm of the opening hole were combined. .

(Comparative Example 3) A drill having a blade diameter (φ) of 0.45 mm and a bush portion having an equal width in the rotation direction of the drill blade and having an inner diameter of 3 mm in the opening hole were combined.

(Comparative Example 4) A drill having a blade diameter (φ) of 0.45 mm and a bush having an equal width in the rotation direction of the drill blade and a bush having an inner diameter of 1.8 mm in the opening hole were combined.

(Comparative Example 5) A drill having a blade diameter (φ) of 0.45 mm and a bush portion having an equal width in the rotation direction of the drill blade and having an inner diameter of 2.1 mm in the opening hole were combined.

(Comparative Example 6) A drill having a blade diameter (φ) of 0.45 mm and a bush having a narrow groove formed in the rotation direction of the drill blade and having a 1.5 mm inner diameter of the opening hole were combined.

(Comparative Example 7) A drill having a blade diameter (φ) of 0.5 mm and a bush having a narrow groove formed in the rotation direction of the drill blade and an inner diameter of the opening hole of 1.8 mm were combined.

(Comparative Example 8) A drill having a blade diameter (φ) of 0.5 mm and a groove having a narrow groove formed in the rotation direction of the drill blade and a bush having an inner diameter of 2.1 mm in the opening hole were combined.

(Comparative Example 9) A drill having a blade diameter (φ) of 0.3 mm and a bush having a narrow groove formed in the rotation direction of the drill blade and having an inner diameter of 2.5 mm in the opening hole were combined.

It is a figure which shows the use condition of the bush for drilling in this invention. It is the schematic of the printed wiring board used by this invention. It is the schematic of the bush shape used by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Copper-clad laminated board 2 Prepreg 3 Printed wiring board 4 Lower board 5 Upper board 6 Bush 7 Protruding part 8 Drill 9 Pressure foot 10 Inner diameter of opening hole 11 Drill blade 12 Opening hole 13 Pressing part 14 Groove part

Claims (3)

Drilling in which an opening hole through which a drill blade having a diameter (φ) of 0.45 mm or less passes is formed, and a peripheral portion of the opening hole is formed on a pressing surface for pressing a printed wiring board to be drilled by the drill blade A method for manufacturing a printed wiring board for drilling using a bush for a work, wherein the ratio of the inner diameter of the opening hole to the diameter of the drill blade is 4 to 7,
Drilling is performed using a drilling bush provided with a groove formed narrowly in the rotation direction of the drill blade from the periphery of the opening hole toward the opening hole on the pressing surface. A method for manufacturing a printed wiring board. Drilling in which an opening hole through which a drill blade having a diameter (φ) of 0.45 mm or less passes is formed, and a peripheral portion of the opening hole is formed on a pressing surface for pressing a printed wiring board to be drilled by the drill blade A printed wiring board manufacturing method for drilling using a bush for a machine,
The inner diameter of the opening hole is 1.8 mm to 2.1 mm, and the pressing surface is provided with a groove portion that is narrowly formed in the rotation direction of the drill blade from the periphery of the opening hole toward the opening hole. The printed wiring board manufacturing method characterized by drilling using the drilling bush.   The printed wiring board manufactured with the manufacturing method of the printed wiring board of Claim 1 or 2.

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