GB2179884A - Method of punching a laminate for electrical use - Google Patents

Method of punching a laminate for electrical use Download PDF

Info

Publication number
GB2179884A
GB2179884A GB08619051A GB8619051A GB2179884A GB 2179884 A GB2179884 A GB 2179884A GB 08619051 A GB08619051 A GB 08619051A GB 8619051 A GB8619051 A GB 8619051A GB 2179884 A GB2179884 A GB 2179884A
Authority
GB
United Kingdom
Prior art keywords
laminate
punching
electrical use
blank holder
holes
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB08619051A
Other versions
GB2179884B (en
GB8619051D0 (en
Inventor
Osamy Yamada
Hiroya Murakami
Hideki Eriguchi
Kenji Tsukanishi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Showa Denko Materials Co ltd
Original Assignee
Hitachi Chemical Co Ltd
Hitachi Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Chemical Co Ltd, Hitachi Ltd filed Critical Hitachi Chemical Co Ltd
Publication of GB8619051D0 publication Critical patent/GB8619051D0/en
Publication of GB2179884A publication Critical patent/GB2179884A/en
Application granted granted Critical
Publication of GB2179884B publication Critical patent/GB2179884B/en
Expired legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/02—Apparatus or processes for manufacturing printed circuits in which the conductive material is applied to the surface of the insulating support and is thereafter removed from such areas of the surface which are not intended for current conducting or shielding
    • H05K3/04—Apparatus or processes for manufacturing printed circuits in which the conductive material is applied to the surface of the insulating support and is thereafter removed from such areas of the surface which are not intended for current conducting or shielding the conductive material being removed mechanically, e.g. by punching
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
    • B26F—PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING
    • B26F1/00—Perforating; Punching; Cutting-out; Stamping-out; Apparatus therefor
    • B26F1/02—Perforating by punching, e.g. with relatively-reciprocating punch and bed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D28/00—Shaping by press-cutting; Perforating
    • B21D28/24—Perforating, i.e. punching holes
    • B21D28/26—Perforating, i.e. punching holes in sheets or flat parts
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/0011—Working of insulating substrates or insulating layers
    • H05K3/0044—Mechanical working of the substrate, e.g. drilling or punching
    • H05K3/005—Punching of holes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
    • B26F—PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING
    • B26F2210/00—Perforating, punching, cutting-out, stamping-out, severing by means other than cutting of specific products
    • B26F2210/08—Perforating, punching, cutting-out, stamping-out, severing by means other than cutting of specific products of ceramic green sheets, printed circuit boards and the like

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Forests & Forestry (AREA)
  • Manufacturing & Machinery (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)
  • Manufacture Of Motors, Generators (AREA)

Abstract

The method, which is suitable for preventing occurrence of cracks (14, Fig. 2) between adjacent holes (13) punched in the printed board 11, is carried out using a punching device comprising punches 6, a die 5 and a hold-down 9 by setting the area pressure of the hold-down to be equal to or greater than 20% of the tensile strength of the laminate 11, while the punching operation is effected at room temperature, thereby dispensing with heating of the laminate and enhancing the accuracy in the distance between the centres of the punched holes (13, Fig. 2) as well as the productivity thereof. <IMAGE>

Description

SPECIFICATION Method of punching a laminate for electrical use The present invention relates to a method of punching a laminate for electrical use, such as insulated laminate, copper clad laminate, printed circuit board or printed wiring board, and particularly to a method of punching a laminate for electrical use which is suitable for preventing occurrence of defects in punching operation such as generation of cracks between the punched holes.
In a prior art punching device of a laminate for electrical use, an oil actuated holding force is applied in the punching device during the time punching operation is effected in order to prevent generation of cracks extending from the punched holes, bends thereabout and separation of laminated layers of the laminate for electrical use.
With such a process of punching holes using the above described punching device, however, no measure has been taken to prevent cracks from being generated between adjacent holes punched in the laminate for electrical use in case the distance there#etween is small.
Further, since punching of holes in the laminate for electrical use has been effected after heating the laminate to a high temperature (60-80 C) in order to prevent generation of cracks between adjacent holes, the accuracy in the distance between the centers of the punched holes tends to be deteriorated due to shrinkage of the laminate after the temperature of the board descends. Further, the requirements such as an areal pressure applied by a blank holder for preventing generation of cracks other than between adjacent holes, shear droop and separation of laminated layers of the laminate for electrical use occurring during the punching operation have not been clarified.
It is an object of the present invention to solve the problems occuring in the above described prior art technique and to prevent cracks from being generated between adjacent holes in a laminate for electrical use by applying a predetermined blank holder areal pressure during the punching operation thereof, while punching operation is effected at the room temperature so as to dispense with heating of the laminate and to enhance the accuracy in size of the punched holes as well as the productivity thereof.
In order to achieve the above object, a method of the present invention is characterized by setting the blank holder areal pressure to be given to the laminate for electrical use in a punching device of the laminate comprising punches, a die and a blank holder to be equal to or more than 20% of the tensile breaking strength of the laminate.
Further, the present invention is characterized by applying the areal pressure of the blank holder around the respective punched holes in the region concentric therewith and having the area around each hole of the radius equal to or more than twice the radius of each punched hole.
Figure 1 is a side view partly in cross-section showing a punching device of a laminate for electrical use to which a method of punching operation according to the present invention is applicable; Figure 2 is a plan view showing the cracks generated in a laminate for electrical used; Figure 3 is a side view partly in cross-section showing the flow of material generated in a laminate for electrical use during the punching operation; Figure 4 is a plan view showing a circumferential stress generated in a laminate for electrical use during the punching operation; Figure 5 is a diagram showing a rate of generation of cracks between adjacent holes punched in a laminate for electrical use; Figure 6 is a cross-sectional view showing a blank holder used in varying an areal pressure given to a laminate for electrical use; and Figure 7 is a diagram showing the relationship between the influence of the region, in which a blank holder areal pressure is applied to a laminate for electrical use and a rate of generation of cracks.
An embodiment of the present invention will be described below referring to the accompanying drawings, in which, Fig. 1 is a side view partly in cross-section showing a punching device to which a method of punching according to the present invention is applicable. In Fig. 1, the puching device comprises a lower die set 1, upper die set 2 vertically movably supported by posts 3 fixedly secured to the lower die set 1 with compression springs 4 arranged around the respective posts 3, a die 5 secured to the lower die set 1 and having through-holes 5a formed therein, and punches 6 secured to the upper die set 2 in facing relationship to the through-holes 5a of die 5 with a backing plate 7 and a punching plate 8 arranged for securing the punches 6 in position.
A blank holder 9 is secured at the lower tip of each rod 10 which is hanged to the upper die set 2, and the blank holder 9 is formed with guide holes 9a each positioned in alignment with the respective through-hole 5a. A laminate for electrical use 11 is interposed in position between the die 5 and the blank holder 9, and holding force applying rods 12 pass through the upper die set 2, the backing plate 7 and the punch plate 8 with the tips thereof contacting with the board holder 9.
When the punching operation of the laminate 11 is carried out by using the punching device for the laminate constructed as described above, the punching device is secured to a bolster (not shown) of a press, and a punching force F1 necessary for punching holes in the laminate 11 is applied to the upper die set 2 and, at the same time, a blank holding force F2 is applied to the holding force applying rods 12. In the above described condition in which the blank holder 9 is pressed against the laminated 11 with the above described holding force F2, the punches 6 pass through the printed board 11 after passing through the guide holdes 9a of the blank holder 9 by the punching force F and enter into the through-holes 5a in the die 5. Thus, holes of the predetermined sizes are formed in the laminate for electrical use 11.
The present invention is not affected by any kinds of pressure applying apparatus and any apparatus such as a oil type double-acting press can be used insofar as the apparatus can apply the punching force F, as well as the blank holding force F2.
In the above described embodiment, under the condition that the areal pressure of the blank holder 9 was set to be 0 kgf/mm2 and the ratio d/t of the diameter d of the punched hole with respect to the thickness t of the laminate for electrical use 11 was varied, and cracks 14 were generated around the punched holes 13 in the direction of thickness of the board 11 as shown in Fig. 2. The cracks 14 render the laminate 11 to be inferior in that they deteriorate the electric characteristics, particularly, the insulation resistance between the adjacent holes 13, 13 in the laminate 11 and tend to cause short-circuiting between the wiring on the laminate.
As a result of investigation in detail of the process of punching for finding out the cause of generation of the cracks 14, the horizontal or the lateral flow 15 of material of the laminate is made larger as shown in Fig. 3 when the ratio d/t of the laminate 11 is small, and the annular projection 16 generated around the respective hole 13 is made larger in proportion to the amount of the lateral flow of the material. Thus, it has been found out the circumferential stress ntW around the respective punched hole 13 caused by the operation of the punch 6 is made greater to develop crevices perpendicular to the stress 0 to form the above cracks 14 (Fig. 2).
As to the countermeasure against generation of the above cracks, it is deemed effective to suppress the annular projection 16 around the punched hole 13 by applying the blank holder pressure of the blank holder 9 against the laminate for electrical use 11 so as to reduce the circumferential stress nft which is the cause of generation of the cracks.
Upon investigation of generation of the cracks 14 (Fig. 2) in using the punch 6 of the punching device shown in Fig. 1, wherein the one side clearance between the punch 6 and the die 5 is set to be 5% and the holding force F2 is varied, results as shown in Fig. 5 are obtained.
Fig. 5 shows the ratio of the blank holder areal pressure (q) with respect to the tensile strength (nub) in the abscissa and the ratio of the diameter (d) of the punched hole 13 in the laminate 11 at the time of occurrence of the cracks between the adjacent holes with respect to the thickness (t) of the laminate 11 in the ordinate. The curves P-d/2 P-d/2 P-d/2 A(----~=3.0), B( =4.0) and C( =5.0) d/2 d/2 d/2 show the rate of generation of the cracks, respectively. The above described q (the blank holder areal pressure) is the value of the blank holding force F2 divided by the contact area of the printed board 11 with the blank holder 9, and P is the pitch between the adjacent punched holes 13, 13.
As is clear from Fig. 5, when the blank holder areal pressure q is set to be 20% of the tensile strength nB of the laminate 11, generation of cracks 14, 14 between adjacent holes 13, 13 can be positively prevented.
Further, a rate of generation of cracks was investigated within the region in which the effective blank holding function is obtained by using a blank holder 17 having an annular concentric projection 17b of the height of 1 mm and the diameter of D concentric with the guide hole 17a formed at one side (at the side facing to the laminate for electrical use) and setting the blank holder areal pressure to be a constant value of 20% of the tensile strength of the printed board, the diameter D being varied for the investigation.
The results of the investigation are as shown in Fig. 7. Fig. 7 shows the rate of generation of cracks (%) in the ordinate and the ratio of the outer diameter (d) of the guide hole in the abscissa, and the influence of the area of the blank holder 17 in which the blank holder pressure is applied to the laminate for electrical use 11 given to the rate of generation of the cracks is shown in Fig. 7. It is clear from the curve E blank holder areal pressure =0.2) tensile strength in Fig. 7 that the effective region in which the blank holder pressure effectively prevents generation of cracks is the region having the radius of at least twice the radius of each punched hole of the laminate 11, while the blank holder areal pressure equal to or greater than 20% of the tensile strength of the laminate is required for preventing the generation of cracks.
As described above, since the punching operation can be carried out at the mom temperature according to the method of the present invention, shrinkage of the distance between the center of the holder caused by the heating during the punching operation is positively avoided, while cracks which might be generated between adjacent holes in the laminate for electrical use during the punching operation is prevented so that accuracy in the size of the holes and the productively are enhanced.

Claims (5)

1. Method of punching holes in a laminate for electrical use by using a punching device comprising punches, dies and a blank holder, characterized by setting the areal pressure of said blank holder to be equal to or greater than 20% of the tensile strength of said laminate.
2. Method of punching a laminate for electrical use according to claim 1, characterized by applying said set blank holder areal pressure in the region around the respective punched hole in the laminate concentric therewith and having an area having a radius equal to or greater than the radius of said punched hole.
3. Method of punching holes in a laminate for electrical use, characterized by actuating punches for punching said holes while an areal pressure equal to or greater than 20% of the tensile strength of said laminate is applied over a region having the radius of at least twice the radius of said punched hole from the center thereof.
4. Method of punching a laminate for electrical use according to claim 3, characterized by applying said areal pressure by annular projections formed on a blank holder around the respective hole for holding said laminate.
5. Method of punching holes in a laminate for electrical use, substantially as herein described with reference to and as shown in the accompanying drawings.
GB8619051A 1985-08-07 1986-08-05 Method of punching a laminate for electrical use Expired GB2179884B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP60172350A JPS6234798A (en) 1985-08-07 1985-08-07 Method of punching printed substrate

Publications (3)

Publication Number Publication Date
GB8619051D0 GB8619051D0 (en) 1986-09-17
GB2179884A true GB2179884A (en) 1987-03-18
GB2179884B GB2179884B (en) 1989-04-05

Family

ID=15940269

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8619051A Expired GB2179884B (en) 1985-08-07 1986-08-05 Method of punching a laminate for electrical use

Country Status (5)

Country Link
JP (1) JPS6234798A (en)
KR (1) KR870002754A (en)
CN (1) CN1011206B (en)
GB (1) GB2179884B (en)
SG (1) SG48189G (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2663807A1 (en) * 1990-06-26 1991-12-27 Philips Composants APPARATUS AND SYSTEM FOR PUNCHING PRINTED CIRCUITS.
EP0492110A1 (en) * 1990-12-22 1992-07-01 Robert Bosch Gmbh Method for connecting a flexible printed circuit board to an electrical component, apparatus obtainable thereby as well as a device for assembling a flexible printed circuit board
WO1999025507A2 (en) * 1997-11-19 1999-05-27 Feintool International Holding Ag Device for producing a workpiece by stamping
CN110154154A (en) * 2019-05-29 2019-08-23 安徽大华半导体科技有限公司 A kind of Trim Molding device

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3930300B2 (en) * 2001-11-20 2007-06-13 日本碍子株式会社 Punching die for simultaneous punching
CN101322993B (en) * 2004-05-10 2011-09-21 倍科有限公司 Trimming device
CN101637926B (en) * 2009-07-28 2013-06-19 珠海元盛电子科技股份有限公司 Steel knife die for making bonding course and method for making bonding course
CN102189565A (en) * 2010-03-17 2011-09-21 车兆丰 Sheet device packaging blind hole paper tape and stamping method and special stamping die thereof
JP5197870B1 (en) * 2012-02-11 2013-05-15 株式会社メイク・ア・ボックス Punching machine balance correction sheet manufacturing method, punching machine balance correction type, punching machine balance correction method, and punching machine balance correction sheet
CN102886425A (en) * 2012-09-17 2013-01-23 芜湖市续元工贸有限公司 Punching die of sheet metal part
CN102990710A (en) * 2012-10-29 2013-03-27 茅惠杰 Improved punching structure
CN103753642B (en) * 2013-11-08 2015-12-30 青岛盈科精密橡塑有限公司 A kind of positioning molding mould for polymer high-viscosity glue product
CN106604556B (en) * 2017-02-23 2018-01-19 江西联益电子科技有限公司 A kind of PCB processing unit (plant)
CN106925812B (en) * 2017-03-10 2018-09-18 长沙天恒测控技术有限公司 Unpowered drill for electrical sheet surface insulation resistance measuring device
CN109721235B (en) * 2019-01-22 2024-09-13 江苏先河激光技术有限公司 Cell-phone display screen lobe of a leaf device and cell-phone display screen processing system
CN110014476B (en) * 2019-04-12 2020-11-10 江苏神通阀门股份有限公司 Use method of rubber diaphragm punching shear die
CN110202638B (en) * 2019-06-12 2021-06-04 惠州市盈帆实业有限公司 Manufacturing method of counter bore of composite circuit board

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB465197A (en) * 1934-07-27 1937-04-27 Charles Hathaway Howland Shear Improvements relating to the cold working of materials
GB465196A (en) * 1935-07-27 1937-04-27 Charles Hathaway Howland Shear Improvements relating to the production of cold flow in substances
GB465198A (en) * 1934-07-27 1937-04-27 Charles Hathaway Howland Shear Improvements relating to the mechanical working of substances

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59169799A (en) * 1983-03-15 1984-09-25 塩出　高睦 Hydraulic precise punching press

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB465197A (en) * 1934-07-27 1937-04-27 Charles Hathaway Howland Shear Improvements relating to the cold working of materials
GB465198A (en) * 1934-07-27 1937-04-27 Charles Hathaway Howland Shear Improvements relating to the mechanical working of substances
GB465196A (en) * 1935-07-27 1937-04-27 Charles Hathaway Howland Shear Improvements relating to the production of cold flow in substances

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2663807A1 (en) * 1990-06-26 1991-12-27 Philips Composants APPARATUS AND SYSTEM FOR PUNCHING PRINTED CIRCUITS.
EP0463693A2 (en) * 1990-06-26 1992-01-02 Philips Circuits Imprimes Apparatus and system for punching printed circuit boards
EP0463693A3 (en) * 1990-06-26 1992-02-26 Philips Composants Apparatus and system for punching printed circuit boards
US5253559A (en) * 1990-06-26 1993-10-19 U.S. Philips Corp. Device and system for piercing printed circuits
EP0492110A1 (en) * 1990-12-22 1992-07-01 Robert Bosch Gmbh Method for connecting a flexible printed circuit board to an electrical component, apparatus obtainable thereby as well as a device for assembling a flexible printed circuit board
US5193270A (en) * 1990-12-22 1993-03-16 Robert Bosch Gmbh Method for joining a conductor track foil to an electrical component
US5289629A (en) * 1990-12-22 1994-03-01 Robert Bosch Gmbh Apparatus for joining a conductor track foil to an electrical component
US5345040A (en) * 1990-12-22 1994-09-06 Robert Bosch Gmbh Device including a conductor truck foil
WO1999025507A2 (en) * 1997-11-19 1999-05-27 Feintool International Holding Ag Device for producing a workpiece by stamping
WO1999025507A3 (en) * 1997-11-19 1999-12-09 Feintool Int Holding Device for producing a workpiece by stamping
CN110154154A (en) * 2019-05-29 2019-08-23 安徽大华半导体科技有限公司 A kind of Trim Molding device
CN110154154B (en) * 2019-05-29 2021-06-15 安徽大华半导体科技有限公司 Rib cutting forming device

Also Published As

Publication number Publication date
KR870002754A (en) 1987-04-06
JPS6234798A (en) 1987-02-14
GB2179884B (en) 1989-04-05
CN86104935A (en) 1987-02-04
GB8619051D0 (en) 1986-09-17
CN1011206B (en) 1991-01-16
SG48189G (en) 1989-12-08

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PCNP Patent ceased through non-payment of renewal fee

Effective date: 19930805