DE102006012291A1 - Printed circuit board drilling or boring device, uses annular body for removing drilling chips from boring tool in two radial planes - Google Patents

Abstract

A boring device requires several stacked circuit boards, and a work piece to be bored is formed on a work bench, and a vertically movable stamp is used for pressing the work piece from above against the positioning surface of the work bench. The annular body for removing boring chips at the boring tool in two separate radial planes with selected axial spacing, has several airway channels for connecting the air outside of the stamp into the central recess of the annular body and extends outside the periphery of the annular body to the central recess.

Description

technical Area of the device

The The present invention relates to a device for drilling of printed circuit boards for electronic Equipment, Apparatus and equipment. Through the holes can be continuous Holes formed become. In this case, the drilling device is suitable for several Stacking stacked Piercing printed circuit boards, the drill chips are effectively removed have to, for adequate cooling to be able to secure the drill the for the quality the drilling work is significantly responsible.

State of technology

The in electronic devices, Apparatus and equipment used circuit boards are with continuous holes provided to electrical connections between individual circuits to produce the circuit boards. The holes are usually with Drills produced. The drills are usually at the front end held a spindle, the height adjustable is trained. Here is a vertically movable trained stamp present, with the to be pierced PCB stack at Drilling in the vicinity of the hole to be executed from above against the bearing surface a workbench be pressed firmly can. The stamp contains at its bottom, the PCB stack facing bottom one replaceable trained ring body, which is a central hole Having the free passage of the drill. Interchangeable with this trained ring body at the bottom of the vertically adjustable punch can be safe be placed in the vicinity of the PCB stack to hole to be drilled during the drilling process firmly pressed against the support surface of the workbench becomes (see the following reference 1)

In 13 The present application is a known device for drilling a workpiece 1 shown. The known device comprises a workbench 2 with a flat bearing surface on which the workpiece 1 Here, this consists of several stacked to a stack of printed circuit boards 11 consists. A vertically adjustable stamp is with 3 referred to, with the PCB stack in the vicinity of the hole to be drilled during drilling from above against the support surface of the workbench 2 is held firmly pressed. A lifting device is with 7 designated, with which the stamp 3 together with a spindle 6 and one at the bottom of the spindle 6 held drill 5 can be raised and lowered vertically.

On the top circuit board 11 of the printed circuit board stack is a cover plate 12 and below the bottom circuit board 11 of the PCB stack is a bottom plate 13 resting on the support surface of the workbench 2 lies. The one from the cover plate 12 and the bottom plate 13 Double-sided printed circuit board stacks are stamped 3 from above against the support surface of the workbench 2 pressed, as in the above-mentioned reference 1 described, a ring body 4 made of metal or plastic with its central hole to the passage of the drill at the free lower end of the punch is arbitrarily interchangeable held. About the ring body of each PCB stack is pressed during the drilling process with sufficient strength against the workbench. For this purpose, the lifting device 7 lowered to a predetermined level. The ring body presses 4 by means of a spring mechanism not shown in connection with the lifting device with a predetermined contact pressure from above against the workpiece 1 on the support surface of the workbench 2 pressed.

In this state, the spindle 6 lowered, and with the drill 5 at the lower end of the spindle 6 becomes a hole in the workpiece in a predetermined manner 1 drilled. The resulting chips in the drilling work, as explained below, via an outlet opening 8th on an outer side surface of the hollow punch 3 sucked together with air by means of a suction device, not shown. In this case, there are for extracting the chips from the wellbore on the outer lateral annular surface of the annular body 4 from outside to inside continuous channels 10 ( 14 ), which is the external environment of the ring body 4 to the central hole 9 in the ring body 4 to the passage of the drill 5 connect, so that by means of a suction device at the outlet opening 8th Air from the outer environment of the ring body 4 over the channels 10 a central hole 9 and the subsequent cavity of the stamp 3 can be sucked together with the drilling chips.

14 shows the example of training a ring body 4 in 14 (1) in longitudinal section and in 14 (2) along the lines XX in cross section. The ring body 4 has several channels from the outside to the inside 10 attached to the perimeter of the central drill hole 9 of the ring body 4 in the same way eccentrically offset something, so that during the drilling process, in which the ring body 4 against the workpiece 1 pushes, by sucking air through the side exhaust port 8th By means of a suction device, an air vortex circulating around the drill is generated, which is intended to prevent the drill chips from forming on the drill 5 stick to it.

The vortex flow also serves to cool the drill 5 To prevent a drill with elevated temperature the plastic from which the circuit boards are made at certain points disadvantageously softening and damage the circuit boards.

When the chips on the drill 5 are not effectively sucked, it is easy to break the drill 5 , It is therefore particularly important that the air vortex flows are directed to the drill so that the chips can be sufficiently sucked and the drill 5 so that it can be cooled sufficiently.

to Removal of drill cuttings is a construction known over an air supply ducts at the bottom Add air to the end of the punch in the area of the drill to while blowing away the drill cuttings (See reference 2 below). It is also a suggestion become known, in which two different compressed air sources are provided. So there is a membrane on the lower bottom surface of the stamp the one between itself and the bottom surface of the stamp Drilling area enclosing Pressure-sealed annulus, which is connected to one of the compressed air sources to over the Membrane to deliver a predetermined contact pressure on the workpiece to be drilled while the second compressed air source is connected to supply channels in the area of the drill is to the drill chips blow away on the drill (see reference 3 below). Besides that is A construction has been proposed in which a liquid mist is blown into the area of the drill for its cooling (see References 4 and 5).

It Furthermore, a construction has become known in which a separate Air supply duct up led into the area of the drill which is opened to blow away the chips when the jig is raised after drilling (see reference below 6). About that In addition, a construction has become known in which the air supply passage by means of a spring mechanism during the upward movement of the tensioning device open is, the air supply duct in a ring body is arranged at the lower end of the clamping device (see Reference 7).

[Reference 1]

• Laid-open Japanese Patent Application Hei 5-285891

[Reference 2]

• Laid-open Japanese Patent Publication Sho 63-300807

[Reference 3]

• Laid-open Japanese Patent Hei 3-3713

[Reference 4]

• Japanese Patent 351376

[Reference 5]

• Japanese Utility Model Application Hei 6-17847

[Reference 6]

• Japanese Patent Application 2000-5910

[Reference 7]

• Patent Application 2004-130454

disadvantage of the prior art and object of the present invention

Of the Subject of the application according to the above reference 1, at the annular gap between the drill and the drill through hole in the ring body if possible at the lower end of the stamp is kept tight and the PCB stack on the ring body at Drilling firmly pressed against the support surface of the workbench can be, so that the degree of formation in the environment of a through hole can be largely suppressed by the stack of plates, at the same time but also the chips by the resulting in the extraction of air in the area of the drill Eddy current are discharged together with the sucked air should, proved to be less effective in terms of the extraction of the chips.

at the constructions disclosed in the prior art (2) and (3) Although satisfactory cooling reached the drill. The removal of the drill chips by blowing compressed air carries the risk of drilling chips due to lack of regulation of the air supply to the printed circuit boards can be blown.

at the above prior art (4) and (5) there is a risk that by the liquid added to the air, the chips inside stick the stamp and thus effective extraction of the Chips or Dust removal of the system is prevented.

To fix these drawbacks, the free air gap between the drill near its spit ze and the narrow bore through hole in the ring body at the lower end of the punch to achieve an increased air flow are further narrowed. When the hole is funnel-shaped in the ring body toward the rear end of the drill, the air flow is cooled at an increased air velocity in the narrow air gap between the wall surrounding the hole and the drill as it passes into the funnel-shaped enlarged hole, thereby increasing the efficiency of the drill can be cooled. However, there is the problem that the air pressure is lowered when sucking the air through a lateral opening in the punch, so that the circuit board stack is sucked in a disadvantageous way with the stacked circuit boards.

The Constructions in the above prior art contain separate Air outlet openings, the only open when the jig is raised after a drilling operation becomes. This can be a suction of the PCB stack by pressure drop in the suction avoid reaching airflow.

In recently, Time is the trend toward miniaturization of printed circuit boards continuing what is the formation of boreholes in the printed circuit boards with extremely small hole diameters (e.g., 0.2 mm) required power. This pile up breaks of drills, because the drill chips attaching to a drill do not can be sufficiently eliminated including the cooling the drill is unsatisfactory. There is therefore an urgent need, the Elimination of drilling chips and at the same time the cooling the drill, especially for holes with drill diameters from e.g. 0.2 mm in PCB stacks of miniaturized printed circuit boards, Compared to the prior art with significantly increased effectiveness with justifiable solved technical effort safely to get.

Of the Invention is therefore the object of a device for Drilling PCB stacks - even from miniaturized ones PCBs - specify the disadvantages of the prior art by significantly increased cooling capacity compared to the Drills (in particular also with borehole diameters of, for example, 0.2 mm) with simultaneous increased discharge of drill shavings safely avoids.

Inventive solution of task

The Task is according to the invention with the features of claim 1. Advantageous versions According to the invention will become apparent from the features of the claims and / or the description.

The The invention relates to a drilling device for drilling holes in PCBs for electronic equipment, Apparatus and devices, wherein a plurality of printed circuit boards to a Stacked on top of each other a workpiece to be drilled on a workbench and one in the vertical form of training Stamp for pressing of the workpiece from above against the support surface the workbench is provided, with the bottom of the punch a any interchangeable ring body held with a central recess for passage of the drill is, and the ring body for pressing the workpiece against the support surface the workbench in a chosen narrow drilling area for warranty a safe bore is formed suitable.

The The above device is for this purpose according to the invention characterized in that the ring body for removing drilling chips at the drill in two separate radial planes with selected axial Distance from each other has a plurality of channels for connecting the air outside of the punch in the central recess of the annular body from the outer side Circumference of the ring body run to the central recess of the ring body and there in the chosen one axial distance to the recess in such a way brought to the terminal are that by sucking air from the environment of the punch over his Cavity through first channels air sucked in the radial upper plane in a first upper one Section of the drill forms a first upper turbulence around the drill and at the same time through second channels in the radially lower level sucked in air in a second lower section of the drill in the Area of its drill bit a second lower vortex flow around form the drill.

Advantageously, the recess of the annular body for passage of the drill in the lower, the workpiece-facing portion of a cylindrical bore with a selected relatively narrow diameter, the tapered in a predetermined manner away from the workpiece adjacent upper region for connection opening of the annular body at the bottom of the punch is extended and wherein the radially outwardly inwardly extending first channels in an upper conically widened region of the recess of the annular body outside its lower cylindrical portion and connect the outside to the inside star-shaped second channels to the lower cylindrical portion of the recess near the workpiece wherein the number of the first and second channels and their Luftdurchlaßquerschnitte and their connections to the recess of the annular body with respect to the diameter and the axial length of the cylindrical portion of the annular body s as well as the nature of its cone-shaped Extension and the suction pressure at a lateral wall opening to the hollow interior of the punch are chosen such that the first channel into the recess of the annular body supplied exhaust air forms such a first turbulent flow in the region of the conical extension and thereby has such a pressure drop that the chips from the drilling area above the hollow punch optimally get to the discharge and that the air supplied via the second channels forms such a second vortex flow in the region of the cylindrical portion of the recess near the drill bit with comparatively high air velocity, on the one hand prevents the drill chips from sticking to the drill and on the other hand by adiabatic expansion of the vortex flow effective cooling of the drill is achieved.

The inventive device can advantageously be designed such that the second channels in the workpiece facing bottom of the ring body consist of grooves of predetermined dimensions by the Placing the ring body on the workpiece closed channels form over the in the cylindrical portion of the recess a high eddy current velocity for safe replacement the drill chips reached from the drill tip and sufficient cooling of the drill becomes.

This let yourself also according to the invention achieve that the second channels are formed as bores extending in a radial plane of the ring body near the workpiece from the lateral outer wall of the ring body extend continuously into its cylindrical region.

advantageously, is the device according to the invention formed such that the sum of the cross sections of the second channels smaller than the sum of the cross sections of the first air channels, so that by means of the second channels a relatively high eddy current velocity in the cylindrical region of Recess of the annular body can be achieved substantially near the top of the drill. The can same size open cross sections of the first channels each be much larger as the open cross sections of the second channels, the number of the first, e.g. 8, star-shaped arranged first channels larger, e.g. be twice as big can, like the second channels and, wherein the first and correspondingly the second channels to the circular recess across from its axial center to achieve rotating in the same direction first and second turbulent flows each offset by the same amount connect.

It may also be beneficial to the cylindrical circumference of ring body in the area of the outer inlet openings the first channels to arrange a collar rotatably, the openings in the cross section of inlet openings the first channels or has larger wherein in an initial position, the openings in the adjusting ring with their full cross sections unthrottled in front of the inlet openings the first channels to come to rest and to regulate the equally throttled inlet openings the first channels is formed radially rotatable, wherein the adjusting ring in dependence of the rotational position of the inlet openings the first channels more or less throttled free and thus the over the Interior of the stamp sucked air quantity according to the required ratios can be made adjustable.

Advantages of invention

One Substantial advantage of the invention is also that in the ring body at the bottom of the punch for pressing one or more over each other stacked circuit boards and with a central opening to the Passage of Borher radial first or second air supply ducts in two from each other separated radial planes are arranged on the outside air each with selectable pressure can be sucked to axially different areas of the drill with circulating air in a targeted manner for cooling the drill and for removal of drill shavings flush with pressure, according to the respective cooling and chip removal requirements in both axial regions of the bottom, the Ansaugquerschnitte the first air supply channels accordingly chosen are.

preferred embodiments the invention

In the following preferred embodiments of the inventive device for drilling printed circuit boards are explained. The object of the present invention is to provide a device for drilling printed circuit boards, with the aid of which the removal of chips and the cooling of the drill can be carried out effectively. This has been achieved in such a way that at the lower end of the vertically movable up and down punch an annular body is removably held. In an upper first radial plane of the annular body are several first air supply channels, is passed over the externally selectable amounts of air in the center of the annular body for performing the drill, wherein a first vortex flow flows around the drill in a central region and that in a lower second Radial plane of the annular body, which faces the circuit board stack, a plurality of second air supply ducts to deliver a second vortex flow in the center of the annular body, which surrounds the drill in a lower, the drill bit near area, the ratios of the air quantities of the two Luftwir bellows to each other are selectable.

Since the entire structure of the device for drilling printed circuit boards already based on 15 is described, a repetition is unnecessary. With reference to 1 to 3 is below only the releasably secured to the lower end of the punch ring body 4 described in more detail.

1 (1) shows a section through a first embodiment of an annular body according to the invention 4A , 1 (2) shows a radial cross section along the lines AA in FIG 1 (1).

In the ring body 4A are in a radial plane a plurality of first air channels 41 present (eight channels in the present example), which extend from the outer peripheral surface of the annular body to the central recess of the annular body. With the help of the first channels 41 gets air from outside the stamp 3 sucked into the interior of the punch via the central recess of the ring body in order to produce a first turbulent flow in the center of the ring body (FIG. 3 ) to build. At the PCB stack 11 facing bottom surface are grooves (4 grooves in the present case), which rest on the printed circuit board stack 11 second radial channels 42A form. By sucking air from the outside form in the center of the ring body 4A a second vortex flow near the drill bit, not shown here. The channels 41 and 42A each close eccentrically to the central recess of the annular body 4A on, which is funnel-shaped expanded from a PCB stack facing relatively narrow cylindrical bore to the cavity of the punch.

2 (1) shows a section through a second embodiment of a ring body according to the invention. 2 (2) shows a radial cross section along the lines BB in FIG 2 (1).

In the ring body 4B in 2 are located, as in the ring body 4A in 1 , a variety of first channels 41 (Eight channels in the present example), which extend from the outer peripheral surface of the annular body to the central recess of the annular body. With the help of the first channels 41 in an upper first radial plane, the air from outside the punch is also here 3 sucked into the interior to form a first upper vortex flow in the center of the ring body. The printed circuit board 1 facing are in a second radial plane of the annular body second channels 42B which is guided from the outer circumference of the annular body to the central recess of the annular body. Through the second channels 42B Air is sucked in from the outside, wherein in the center of the annular body in the region of its narrow cylindrical passage for the drill a second air vortex flow is formed near the drill bit.

The ring body 4A and 4B in 1 and 2 each have the feature that the cross-sectional sum of the second air channels 42A respectively. 42B is much smaller than that of the first channels 41 the second channels 42A and 42B near the top of the drill 5 to the cylindrical portion of the recess 9 connect the ring body.

3 shows in the axial section the vertical up and down movable punch 3 , at which at its lower end the ring body 4B is releasably attached. Since the cross-sectional sum of the second channels is smaller than that of the first air channels 41 , that passes over both air channels 41 and 42 simultaneously sucked from the outside air in the second air channels 42B with higher flow rate in the central recess of the annular body 4B 9 and there forms a vortex flow at a comparatively higher speed near the drill bit than the air coming out of the first channels 41 exit. The high eddy current velocity in the area of the drill tip prevents drilling chips from sticking to the drill bit tip. Under the adiabatic expansion of the air from the channels 42A and 42B in the cylindrical recess is the drill 5 effectively cooled. This is especially true for the air from the canals 42B ,

The sucked air from the first channels 41 forms a larger second vortex flow axially above the first vortex flow from the air from the second channels 42B is formed, passing through the first channels 41 formed vortex flow allows the chips from a lateral outlet opening 8th of the stamp 3 efficiently sucked to the outside. If with the second air channels 42B exiting air causes excessive pressure reduction, the air takes over from the air ducts 41 a balancing function to regulate the vortex flows.

Since the channels are formed in the annular channel according to the invention so that two axially superimposed vortex flows, from which the drill near the bottom vortex flow has a relatively higher velocity than the upper vortex flow in the region of the drill above its tip, the cross-sectional ratio of the first channels 41 to the second channels 42B in the ring body 4B According to the invention preferably so dimensioned that the cross-sectional total of the second air channels 42B at 10 ~ 50% of the cross-section sum of the first air channels 41 lies.

With the embodiment of the invention according to 3 Corresponding eddy currents will follow as with the embodiment according to the invention 2 scored, even if the grooves 42A in 1 through channels 42B in 3 are replaced. The number of first channels 41 as well as the number of second air channels 42A and 42B in 1 respectively. 3 are not limited to the numbers given here as long as the channel cross-section ratios given above are substantially met.

It There are printed circuit board materials where the drill chips are special can easily adhere to the drill. In such a case can according to the invention with eddy currents further higher Speeds in the vicinity the drill tip are generated.

Thus, according to the invention for each type of material of the circuit boards, the sum of the cross-sectional ratios of the first channels 41 to the sum of the cross sections in the second channels 42A or 42B be determined to a particular suitable annular body for each type of material 4 to be able to use.

In order to keep the number of different ring body as a function of the choice of material of the circuit boards as small as possible, according to the invention an annular body 4 be used, where the first air channels 41 are defined sufficiently large, which can be throttled according to the invention with a shut-off mechanism to the desired cross-sectional size, so that only a ring body is necessary for a number of important or frequently used materials.

As in 4 in a radial section on the circumference of an annular body according to the invention 4C a cylindrical locking sleeve 43 on the ring body 4C rotatably mounted. The collar 43 has a variety of openings 44 on, the same or slightly larger cross-sections as the first air ducts 41 exhibit. In a certain rotational position relative to the ring body 4C are the openings 44 on the collar 43 in coincidence with the inlet openings of the sufficiently large sized first channels 41 , When the collar 43 For example, by means of a positioning device such as a servomotor (not shown) is rotated, the overlap of the inlet openings of the first channels changes 41 with the openings 44 , so that the opening cross-section of the first channels 41 can be chosen arbitrarily. In 4 are the second channels 42A respectively. 42B not shown.

It can with the ring body 4A . 4B and 4C after the 1 to 4 be advantageous to attach to the resting on the circuit board shock bottom surfaces of the ring body, a layer of an elastic material such as rubber or plastic, whereby the ring body 4A . 4B or 4C adheres to the workpiece to be drilled, so that it can be ensured that the annular body on the workpiece from a printed circuit board stack 11 airtight connects. In this way, superfluous air currents on the surface of the printed circuit board stack can be avoided. If an inventive ring body 4A . 4B or 4C completely made of an elastic material, in particular the ring body 4B to 2 and 3 , so let the channels 42B produce without much effort.

According to the embodiment of the invention according to 1

5 shows a photograph of the lower surface of a ring body used in the embodiment 1. The four grooves 42A for forming the second air channels have a width of 0.3 mm and a depth of 0.5 mm. In this case, in the example case, the cross-sectional total of the second air channels 42A 20% of the cross-section sum of the first air ducts 41 ,

With such a ring body drilling tests were carried out with 150 drills, with no breakage of the drill occurred. But the photo shows in 6 in that a considerable amount of chips still adhered to the drill after the drilling work.

According to the embodiment of the invention according to 2

7 shows a photograph of the underside of the ring body used in the embodiment 2. The four grooves 42A to form the second air channels have a width of 1.0 mm and a depth of 1.5 mm. In this case, the cross-sectional total of the second air channels is in the example case 42A 19.9% of the cross-section sum of the first air ducts 41 ,

With such a ring body drilling tests were carried out with 150 drills, with no drill break occurred. After drilling, five out of 150 drills found that a comparatively small amount of chips adhered to the drill (Photo of 8th ). This finding represents an improvement compared to a comparative example to be explained below. If maintenance was performed on the drill during the drilling work, it could be achieved that no drill break occurred during the drill life.

9 shows a photograph of the underside of Ringkörkörper used in Embodiment 3 pers 4B , The second air channels close to the lower side of the ring body have a diameter of 1.0 mm. The cross-sectional sum of the second air channels is 20.8% of the cross-sectional total of the first air channels.

When using this ring body 4B The drill tests were carried out with 150 drills with no breakage of the drill bit. As in the photo in 10 All drills after drilling work showed a clean condition with no chips attached. There was no risk of drill breakage during the given drill life. Thus, the object sought by the invention could easily be achieved.

Comparative example

11 shows a photograph of the lower surface of a ring body used for comparison, the four first channels with diameters of 3.1 mm and a reaching into the interior of the punch cylindrical recess, with no second air channels were provided.

Using this pressure ring drilling tests were carried out, with a drill fracture measured relatively early on his life time on every third drill. As in Photo in 12 illustrated, attached to the drill a larger amount of chips. It can therefore be presumed that these chips were responsible for drill bit breakage in larger quantities on the drill bit.

The Drilling experiments were in the above embodiments and the comparative example with the same working parameters, namely a drill diameter of 0.3 mm, a feed rate of 1.5 m / min and a Spindle speed of 100 000 rpm carried out. As for the number of holes were concerned, with the same drill to 3000 holes were accordingly carried out his life, unless a drill break occurred. In all experiments, a ring body was used, of the four channels with a diameter of 3.1 mm.

As above in detail describe a ring body is free at the bottom of the stamp removably attached. In this case, the annular body in a first upper radial plane several first channels for generating a first turbulent flow in the central recess of the ring body through the sucked into the interior of the stamp air on. In a second to the workpiece facing radial plane are several second channels, the a second vortex flow in the central recess of the ring body near the drill bit generate, wherein the air flowing into the second channels a comparatively high flow velocity has to drill the chips detach from the tip of the drill and also it is ensured that a sufficient amount of air over the first channels the recess is present within the annular body to the Chips with Help the first vortex flow over the to carry hollow stamp. By this measure is an effective removal of chips and at the same time a sufficient bur cooling allows whereby the disadvantages by the attachment of chips on the drills in the state the technique can be avoided.

As from the embodiments 1 to 3 is to conclude the second channels in the ring body be precisely sized to ensure optimal replacement of the chips at the Ensure the tip of the drill and also a discharge of the detached chips with the second vortex flow enable to be able to.

The The invention is not limited to the exemplary embodiments shown. For the expert further embodiments readily possible, which do not depart from the scope of the invention.

In the pictures shows:

1 an inventive embodiment of an annular body for drilling holes in a circuit board stack axially and radially cut;

2 a second embodiment of an annular body according to the invention cut axially and radially;

3 Air currents in the central recess of the annular body after 1 and 2 ;

4 a radial section through the ring body after 2 in the plane of the first channels for generating an uppermost air flow in the upper part of the central recess of the annular body;

5 a photograph of the underside of an annular body used in the embodiment 1;

6 a photo of the drill after drilling according to Embodiment 1;

7 a photograph of the underside of an annular body used in the embodiment;

8th a photo of the drill after drilling according to Embodiment 2;

9 a photograph of the underside of an annular body used in the embodiment 3;

10 a photograph of the drill after drilling according to Embodiment 3;

11 a photograph of the underside of a ring body used in a comparative example without channels according to the invention;

12 a photo of the drill after drilling of the comparative example;

13 an axial section through a known device for drilling a printed circuit board stack;

14 an axial section and a radial section through a known ring body and

15 an axial section through a known drilling device for drilling printed circuit board stacks with illustrated air flows for discharging the drill cuttings.

1

workpiece

2

Workbench

3

stamp

4

ring body

4A ~ 4C

ring body

 5

drill

6

spindle

7

lifting device

8th

outlet

9

central Recess of the annular body

10

Channels in one known ring body

11

Boardstacking

12

cover plate of the PCB stack

13

baseplate of the PCB stack

14

First channels in a ring body according to the invention

42A

groove to form second air channels in an inventive

ring body

42B

Second channels a ring body according to the invention

43

collar

44

openings in the collar

Claims (5)

Drilling device for drilling holes in printed circuit boards for electronic devices, apparatus and devices, wherein a plurality of printed circuit boards stacked to form a stacked workpiece on a workbench and a vertically movable trained punch for pressing the workpiece from above against the support surface of the workbench is provided, wherein at the bottom of the punch an arbitrarily replaceable ring body is held with a central recess for passage of the drill, and the ring body is adapted for pressing the workpiece against the support surface of the workbench in a selected narrow bore area to ensure a safe bore, characterized characterized in that the annular body for removing drill cuttings on the drill in two separate radial planes with selected axial distance from each other each having a plurality of air-permeable channels for connecting the air outside of the punch in the central recess of the annular body extending from the outer lateral periphery of the annular body to the central recess of the annular body and are brought there in the selected axial distance to the recess such that by sucking air from the environment of the punch through its cavity by the first channels in the radially upper plane sucked air in the region of a first upper portion of the drill forms a first upper turbulence around the drill and the same sucked through second channels in the radially lower plane air in the region of a second lower portion of the drill near its drill bit a second lower turbulence forms around the drill. Drilling device according to claim 1, characterized that in the workpiece facing bottom of the ring body Grooves are present, which are dimensioned such that by putting on of the ring body on the workpiece closed second channels are formed, so that in the lower region of the recess a high Eddy current velocity to detach the drill cuttings from the drill bit and sufficient cooling of the drill is reached. Drilling device according to claim 1, characterized that the second channels are formed as bores extending in a radial plane of the ring body near the workpiece from the lateral outer wall of the ring body extend continuously into its cylindrical recess. Drilling device according to one of claims 1 to 3, characterized in that the sum of the open cross sections the upper second channels smaller than the sum of the open cross sections of the lower first Air ducts. Drilling device according to one of the preceding claims 1 to 4, characterized in that on the cylindrical outer circumference of the annular body in the region of the outer inlet openings of the upper first channels an adjusting ring is rotatably arranged to have openings in the cross section of the inlet openings of the first channels or larger, wherein in a Starting position of the adjusting ring unthrottled the openings in the collar with its full cross-sections in front of the inlet openings of the first Channels are located and wherein the adjusting ring is designed to be radially rotatable for the selected throttling of the inlet openings of the first channels, that in dependence on the rotational position of the adjusting ring, the inlet openings of the first channels with a selected throttle cross section for regulating the intake air quantity is adjustable.