CN114630498A - Back drilling method and tool - Google Patents
Back drilling method and tool Download PDFInfo
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- CN114630498A CN114630498A CN202210333256.9A CN202210333256A CN114630498A CN 114630498 A CN114630498 A CN 114630498A CN 202210333256 A CN202210333256 A CN 202210333256A CN 114630498 A CN114630498 A CN 114630498A
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- 238000005553 drilling Methods 0.000 title claims abstract description 99
- 238000000034 method Methods 0.000 title claims abstract description 57
- 239000004020 conductor Substances 0.000 claims abstract description 29
- 239000000463 material Substances 0.000 claims abstract description 29
- 230000033001 locomotion Effects 0.000 claims abstract description 16
- 238000007747 plating Methods 0.000 claims abstract description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 19
- 229910052802 copper Inorganic materials 0.000 claims description 19
- 239000010949 copper Substances 0.000 claims description 19
- 238000003672 processing method Methods 0.000 claims description 12
- 238000003754 machining Methods 0.000 claims description 10
- 239000011248 coating agent Substances 0.000 claims description 8
- 238000000576 coating method Methods 0.000 claims description 8
- 230000002093 peripheral effect Effects 0.000 claims description 3
- 238000004891 communication Methods 0.000 claims 1
- 230000008054 signal transmission Effects 0.000 abstract description 13
- 238000005520 cutting process Methods 0.000 description 14
- 229910052751 metal Inorganic materials 0.000 description 10
- 239000002184 metal Substances 0.000 description 10
- 230000008021 deposition Effects 0.000 description 9
- 238000010586 diagram Methods 0.000 description 9
- 230000007704 transition Effects 0.000 description 8
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000012811 non-conductive material Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
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- 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
- H05K3/0047—Drilling of holes
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- 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
- H05K3/40—Forming printed elements for providing electric connections to or between printed circuits
- H05K3/42—Plated through-holes or plated via connections
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- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)
Abstract
The invention relates to a back drilling method and a cutter. The method comprises the following steps: drilling a through hole in the sheet material along the thickness direction of the sheet material, and determining the position of a conductive layer according to the movement distance of a cutter when the conductive region of the cutter is in contact conduction with the conductive layer at a target position on the sheet material in the drilling process; plating a conductive material on the wall of the through hole; judging the area of the conductive layer of the via hole sinking conductive material to be removed; and removing the through hole sinking conductive material of the conductive layer according to the position of the conductive layer. Through the cutter in this application in the drilling process with the conducting layer contact in the sheet material to form with the conducting layer and switch on, thereby can be according to the position information of the movement distance in order to confirm the conducting layer that obtains the cutter, then when boring back to the sheet material, can be according to known conducting layer position information, the removal degree of depth when confirming the drill bit back boring, thereby can accurately bore and remove unnecessary via hole and sink conducting material, and avoid the interior walking line of via hole to be bored absolutely, improve signal transmission quality.
Description
Technical Field
The invention relates to the technical field of printed circuit board manufacturing, in particular to a back drilling processing method and a back drilling tool.
Background
Backdrilling is a special drilling technique for controlling the depth of a drilled hole, in the fabrication of multi-layer boards, such as eight-layer boards, when a first layer needs to be connected to a sixth layer, a through hole is usually drilled first (primary drilling) and then plated with a conductive material, so that the first layer is directly connected to the eighth layer, and in fact, only the first layer needs to be connected to the sixth layer, and then the seventh layer to the eighth layer are connected without a wire, like an extra pillar plated with a conductive material, which in high frequency high speed circuit design can cause the reflection, scattering, delay, etc. of signal transmission, and bring the integrity problem to the signal, so that the extra pillar is drilled out of the back side (secondary drilling) and is called backdrilling.
In the manufacturing process of the multilayer printed circuit board, after the multilayer printed circuit board and an insulating product are pressed together, the thickness is uneven, so that the back drilling depth is carried out according to the conventional processing method of the printed circuit board, the back drilling depth is deviated from the actual back drilling depth of the printed circuit board, the wiring is drilled off or the length of a conductive material is large due to the fact that a via hole is sunk, and signal transmission is affected.
Disclosure of Invention
Therefore, the back drilling method is needed to be provided for the technical problems that the signal transmission is influenced due to the fact that the depth of back drilling according to the conventional processing method of the printed circuit board is deviated from the depth of the actual back drilling position on the printed circuit board, so that the routing is drilled off or the length of the conductive material sinking through the via hole is large.
A back drilling processing method comprises the following steps:
drilling a through hole in the plate along the thickness direction of the plate, and determining the position of a conductive layer according to the movement distance of a cutter when the conductive region of the cutter is in contact conduction with the conductive layer at a target position on the plate in the drilling process;
plating a conductive material on the wall of the through hole;
determining the area of the conductive layer where the via sinking conductive material needs to be removed;
and removing the through hole sinking conductive material of the conductive layer according to the position of the conductive layer.
In one embodiment, the conductive region is disposed on a tip of the tool, and a body of the tool is insulated.
In one embodiment, the conductive region is disposed in a cusp region of the tool tip, and a region of the tool tip other than the cusp region is insulated from a body of the tool.
In one embodiment, the sharp point area is communicated with a tool shank of the tool, and the tool shank is electrically connected with the electric unit.
In one embodiment, in the step "drilling a through hole in a sheet material in a thickness direction of the sheet material, and determining a position of a conductive layer according to a movement distance of a cutter when the conductive region of the cutter is in contact conduction with the conductive layer at a target position on the sheet material during the drilling process", the method further includes:
when the conductive area of the cutter is in contact conduction with the conductive layer of the target position, the acquisition board outputs a pulse signal, and the movement distance of the cutter is fed back through a detector to determine the current position information of the conductive layer.
In one embodiment, the method for determining the current position information of the conductive layer by feeding back the moving distance of the tool through the detector comprises the following steps: and feeding back the position information of the initial position of the cutter through the detector, and feeding back the position information of the cutter when the pulse signal is generated through the detector, so as to obtain the current position information of the conductive layer.
In one embodiment, in the step of removing the via-sinker conductive material of the conductive layer, the method further includes:
the tool is moved to the conductive layer nearest the copper plated area where electrical connection is desired.
In one embodiment, the cutter body periphery of the cutter is provided with a plurality of spiral chip flutes.
The invention also provides a cutter which can solve at least one technical problem.
A cutter is used for realizing the back drilling processing method, the outer peripheral surface of the cutter is wrapped with an insulating coating, and the region outside the insulating coating forms the conductive region.
In one embodiment, the tool comprises a tip in a conical configuration and a blade in a cylindrical configuration.
Has the advantages that:
the back drilling processing method provided by the embodiment of the invention comprises the following steps:
drilling a through hole in the sheet material along the thickness direction of the sheet material, and determining the position of a conductive layer according to the movement distance of a cutter when the conductive region of the cutter is in contact conduction with the conductive layer at a target position on the sheet material in the drilling process;
plating a conductive material on the wall of the through hole;
determining the area of the conductive layer of the via hole sinking conductive material to be removed;
and removing the through hole sinking conductive material of the conductive layer according to the position of the conductive layer.
Through the cutter in this application in the drilling process with the conducting layer contact in the sheet material to when conducting on with the conducting layer and forming the return circuit, can obtain the movement distance of cutter in order to confirm the positional information of conducting layer, then when boring back to the sheet material, can be according to known conducting layer positional information, the removal degree of depth when confirming the drill bit back boring, thereby can accurately bore and remove unnecessary via hole and sink conducting material, and avoid the interior walking line of through-hole to be bored absolutely, improve signal transmission quality.
The embodiment of the invention also provides a cutter, which is used for realizing the back drilling processing method, the peripheral surface of the cutter is wrapped with an insulating coating, and a conductive area is formed in the area outside the insulating coating. The tool is capable of achieving at least one of the technical effects described above.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive labor.
FIG. 1 is a flow chart of a back drilling method provided by the present invention;
FIG. 2 is a first schematic view of a cutter for machining a multilayer board in the back drilling machining method provided by the invention;
FIG. 3 is a schematic view of a tool provided by the present invention;
FIG. 4 is a first waveform diagram formed when the cutting tip and the conductive layer cutting tip form a loop in the back drilling method provided by the present invention;
FIG. 5 is a second schematic view of the cutter for machining a multi-layer board in the back drilling method provided by the present invention;
FIG. 6 is a second waveform diagram formed when the cutting tip and the conductive layer cutting tip form a loop in the back drilling method provided by the present invention;
fig. 7 is a third waveform diagram formed when the knife edge and the conductive layer knife form a loop in the back drilling processing method provided by the invention.
Reference numerals: 100-a cutter; 110-a tool tip; 111-point of the tool nose; 120-a blade body; 130-a shank; 140-chip flutes; 200-plate material; 210-a top conductive layer; 220-a bottom conductive layer; 230-a first conductive layer; 240-a second conductive layer; 250-through holes; 310-metal filings.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.
In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
In the present invention, unless otherwise explicitly stated or limited, the terms "mounted," "connected," "fixed," and the like are to be construed broadly, e.g., as being permanently connected, detachably connected, or integral; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.
It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.
Referring to fig. 1, 2 and 3, fig. 1 is a flow chart of a back drilling processing method provided by the present invention; FIG. 2 is a first schematic view of a cutter for machining a multilayer board in the back drilling machining method provided by the invention; fig. 3 is a schematic view of a tool provided by the present invention. An embodiment of the present invention provides a back drilling method, including the steps of:
s100, drilling a through hole 250 in the plate 200 along the thickness direction of the plate 200, and determining the position of a conductive layer according to the movement distance of the cutter 100 when the conductive region of the cutter 100 is in contact conduction with the conductive layer at the target position on the plate 200 in the drilling process.
Specifically, the board 200 is formed by laminating a plurality of layers of printed circuit boards, and since the inner layer circuit and the outer layer circuit need to be connected in the board 200, a signal transmission hole needs to be arranged in the board 200. In the drilling process, when the conductive area of the tool 100 is in contact with the current conductive layer at the target position on the plate 200, and the tool 100 can be conducted with the current conductive layer to form a loop, the position information of the current conductive layer can be obtained. The through hole 250 is drilled on the plate 200 through the cutter 100, so that the position information of the conductive layer at the target position on the plate 200 is accurately measured, namely, the conductive layer position is measured while drilling, the whole measuring process is simple and convenient, and the back drilling efficiency is improved. The conductive layer of the target position refers to a conductive layer required to obtain position information, and other conductive layers can be ignored.
Further, since the cutter 100 moves in the thickness direction of the sheet material 200 during the drilling process, the measured horizontal positions of all the conductive layers are the same, and thus, only the ordinate position of the conductive layer needs to be measured.
S200, conducting material plating treatment is carried out on the hole wall of the through hole 250.
Specifically, after the drilling is finished, the inner wall of the through hole 250 needs to be plated with a conductive material so that the through hole 250 can be used as a signal transmission hole for connecting the inner layer line and the outer layer line as needed. Preferably, the conductive material is copper, and in other embodiments, the conductive material may also be other conductive materials such as silver. It should be noted that the entire inner wall of the through-hole is entirely plated with copper for process reasons.
S300 determines an area where the conductive layer of the via sinker conductive material needs to be removed.
Specifically, a portion of the through hole 250 is provided with a connecting wire, and the other portion is not provided with a wire, so that for the sake of convenience of distinction, the portion of the through hole 250 provided with a wire is defined as a non-drilled region, and the portion of the through hole 250 not provided with a wire is defined as a back-drilled region. Because the via hole copper deposition in the back drilling area is too long, the integrity of signal transmission is affected, and therefore the via hole copper deposition in the back drilling area needs to be drilled. Since the non-drilled areas are known, the area of the conductive layer of the via-sinker can be determined. It should be noted that the back-drilled region and the non-drilled region in the through hole are measured by a conventional method in the prior art, and are not described in detail.
S400, removing the through hole sinking conductive material of the conductive layer according to the position of the conductive layer.
Specifically, after the copper deposition of the via hole in the removed conductive layer region is determined, the tool 100 is controlled to extend into the through hole 250 from the back drilling region according to the position information of the conductive layer at the target position obtained in S100, the copper deposition of the via hole is removed from the through hole 250, and when the tool 100 removes all the copper deposition of the via hole in the conductive layer region to be removed, the tool 100 stops moving and retracts. Because the cutter 100 completely removes the via hole copper deposit in the conductive layer area to be removed, the residual via hole copper deposit is shortened, the precision of the back drilling depth is improved, the damage of the cutter 100 to the lead in the through hole 250 is avoided, and the signal transmission quality is improved.
With continuing reference to fig. 1, 2 and 3, in one embodiment, in the step of removing the via sinker conductive material of the conductive layer, the method further comprises:
the tool 100 is moved to the conductive layer nearest the copper plated area where electrical connection is desired.
Specifically, as all the via hole copper deposition on one side of the conductive layer which is located in the back drilling area and is closest to the non-drilling area and away from the non-drilling area is completely removed, the residual via hole copper deposition can be made to be shortest, and then the final drilling position is located in the back drilling area and is closest to the non-drilling area, namely, the position information of the final drilling position is determined, the depth of the cutter 100 moving from the initial position to the conductive layer can be determined, so that the process is more concise, the adverse effect on the thickness of the plate material 200 in the lamination process of the multilayer plate is completely eradicated, and the back drilling depth precision is greatly improved. The final drilling position is a position on the sheet material 200 at which the back drilling process by the tool 100 is completed.
In this embodiment, taking fig. 2 as an example, the conductive layer at the target position includes a first conductive layer 230 and a second conductive layer 240, a transition position between a back drilling area and a non-drilling area is defined between the first conductive layer 230 and the second conductive layer 240, when the back drilling area is located below, the first conductive layer 230 is a conductive layer closest to the non-drilling area, and when the back drilling area is located above, the second conductive layer 240 is a conductive layer closest to the back drilling area. By the measurement in S100, the position information of the first conductive layer 230 and the second conductive layer 240 is known, and when back drilling is performed, assuming that the back drilling area is located below, the distance from the cutter 100 to the first conductive layer 230 in the back drilling area can be determined by the position information of the first conductive layer 230 and the position information of the cutter 100 located at the initial position, that is, the back drilling depth can be accurately determined, so that the copper deposition of the via hole is shorter, and the signal transmission efficiency is improved.
Further, since there is a certain distance between the transition position and the first conductive layer 230, a corrected distance value between the transition position and the first conductive layer 230 may be obtained according to a theoretical distance value between the transition position and the first conductive layer 230 and a ratio between an actual distance value and the theoretical distance value between the first conductive layer 230 and the second conductive layer 240, that is, an ordinate value of the final drilling position is a sum of an ordinate value and the corrected distance value of the first conductive layer 230, so that the final drilling position is closer to the transition position, the residual copper deposition of the via hole is shorter, and the signal transmission efficiency is higher. It should be noted that the smaller the distance value between the first conductive layer 230 and the second conductive layer 240, the closer the corrected distance value between the transition position and the first conductive layer 230 and the actual distance value between the transition position and the first conductive layer 230 are.
Referring to fig. 1, 2 and 3, in one embodiment, in the step "drilling a through hole in the sheet material in the thickness direction of the sheet material, and determining the position of the conductive layer according to the movement distance of the cutter when the conductive region of the cutter is in contact with the conductive layer at the target position on the sheet material during the drilling process", the method further includes:
when the conductive area of the cutter 100 is in contact conduction with the conductive layer at the target position, the acquisition board outputs a pulse signal, and the moving distance of the cutter is fed back by the detector to determine the position information of the current conductive layer.
Specifically, the conductive region of the cutting tool 100 is electrically connected to the detector, and when the conductive region is in contact with the conductive layer, the detector can acquire the position information of the cutting tool 100 when the corresponding pulse signal is generated, so as to conveniently and accurately acquire the position information of the conductive layer at the target position on the plate material 200. Preferably, the detector is a grating scale.
In another embodiment, the acquisition board can send a pulse signal when the conductive area of the tool 100 is in contact with the conductive layer, and the distance the tool 100 moves from the initial position to the current conductive layer is determined by the time between the initial position and the time between the triggering of the pulse signal and the speed of movement of the tool 100.
Referring to fig. 2, 3 and 4, fig. 4 is a first waveform diagram formed when the cutting tip 110 and the conductive layer cutter form a loop in the back drilling method according to the present invention. In one embodiment, the method for determining the position information of the current conducting layer by feeding back the moving distance of the tool through the detector is as follows: and feeding back the initial position of the tool and the position of the conductive layer at the target position through a detector to obtain the position information of the current conductive layer.
Specifically, when the conductive area of the tool 100 is in contact with the conductive layer, a loop is formed, and at this time, the collecting plate outputs a pulse signal, a high-potential square wave is given, that is, the output signal of the collecting plate is inverted from 0 to 1 until the conductive area of the tool 100 is separated from the current conductive layer to cause disconnection of the loop, so that the output signal of the collecting plate is inverted from 1 to 0, and when the tool 100 passes through several conductive layers and drilling is completed, the waveform shown in fig. 4 is obtained. When the acquisition board outputs a pulse signal, the detector can acquire the position information of the cutter 100 when the corresponding signal is generated, and then the detector feeds back the information of the initial position of the cutter 100, so that the distance value between the current conducting layer and the initial position of the cutter 100 can be acquired, and the position information of the current conducting layer can be acquired.
Further, referring to fig. 2 in the specification, the conductive layer at the target position further includes a top conductive layer 210 and a bottom conductive layer 220, and the top conductive layer 210 and the bottom conductive layer 220 are respectively located at the top layer and the bottom layer of the board material 200, so that the cutter 100 can directly obtain a distance value between the current conductive layer and the top conductive layer 210 or the bottom conductive layer 220 with reference to the top conductive layer 210 or the bottom conductive layer 220 in the moving process. When the back drilling machining is needed, the sheet material 200 can be machined directly according to the distance value between the first conducting layer 230 and the bottom conducting layer 220 after the sheet material 200 is turned over, so that the initial position of the movement of the cutter 100 does not need to be measured, the measuring process is simpler, and the efficiency is higher.
It should be noted that, in the back drilling process, since the top conductive layer 210 and the bottom conductive layer 220 are already drilled, an aluminum plate needs to be covered above the plate 200, and the position at which the tool 100 is conducted with the aluminum plate is defined as a reference point, and the ordinate of the final drilling position is the sum of the distance value between the first conductive layer 230 and the bottom conductive layer 220, the corrected distance value (the transition position and the corrected distance value of the first conductive layer 230), and the thickness of the aluminum plate.
Wherein, because the conducting layer has certain thickness, the conducting of conducting region and conducting layer can last a period to can confirm the thickness of the conducting layer of target position through the duration of high potential and the velocity of motion of cutter 100, promptly according to the thickness of first conducting layer 230, can obtain more accurate final drilling position information, thereby make the heavy copper of via hole shorter, signal transmission quality is higher.
Referring to fig. 3, 4, 5 and 6, fig. 5 is a second schematic diagram illustrating the machining of the multilayer board by the cutter in the back drilling machining method according to the present invention; fig. 6 is a second waveform diagram formed when the cutting edge and the conductive layer cutting edge form a loop in the back drilling method provided by the invention. In one embodiment, the periphery of the body 120 of the tool 100 is provided with helical flutes 140.
Specifically, when the cutter 100 drills a conductive layer, the metal chips 310 generated by the conductive layer cannot be discharged in time to be accumulated between the cutter 100 and a hole wall, when one end of the metal chips 310 abuts against the conductive region of the cutter 100, and the other end of the metal chips 310 abuts against the conductive layer, the cutter 100 can be conducted with the conductive layer, so that the acquisition board outputs a high potential, as shown in a waveform diagram shown in fig. 6, since the occurrence of the situation is random, the waveform is abnormal, it cannot be determined whether the trigger of the high potential is that the cutter 100 contacts with the current conductive layer in the drilling process, or the conductive region of the cutter 100 is conducted with a loop formed by the conductive layers of other layers through the metal chips 310, and therefore, it is difficult to accurately determine the position of the conductive layer at the target position. Because the plurality of spiral chip flutes 140 are arranged on the periphery of the blade 120 of the cutter 100, metal chips 310 generated by the conductive layer in the drilling process can be discharged as soon as possible, and the accuracy of obtaining the position of the conductive layer is improved to a certain extent.
Referring to fig. 3, 4, 5 and 6, in one embodiment, the conductive region is disposed on the tip 110 of the tool 100, and the blade 120 of the tool 100 is insulated.
Specifically, when chip flutes 140 on tool 100 are poorly drained, there is still the potential for conductive regions of tool 100 to be connected to other conductive layers via metal shavings 310. In the application, the conductive area is arranged on the tool nose 110 of the tool 100, the tool body 120 of the tool 100 is insulated, when the metal chips 310 are discharged through the chip grooves 140 and contact with the tool body 120 of the tool 100 and other conductive layers, the tool 100 cannot form a loop with other conductive layers, and only contacts with the conductive layer currently contacted with the tool nose 110 to form a loop, so that the ideal waveform shown in fig. 4 can be realized, the position information of the conductive layer can be accurately measured, and therefore, the problem that when back drilling is carried out at one time, the position signals caused by the random discharge of the metal chips 310 when the current position information of the conductive layer is detected by the tool 100 are relatively disordered, and the position of a required copper layer is difficult to judge is solved. The cutting edge 110 of the tool 100 refers to a tapered portion of the lower end of the tool 100.
Referring to fig. 3, 4, 5 and 7, fig. 7 is a third waveform diagram formed when the cutting tip 110 and the conductive layer cutter form a loop in the back drilling method according to the present invention. In one embodiment, the conductive region is disposed in the cusp region 111 of the tip 110, and the region of the tip 110 other than the cusp region 111 is insulated from the blade body 120 of the tool 100.
Specifically, since the tool tip 110 of the tool 100 has a point, a certain time is required until the tool tip 110 completely breaks through and breaks away from the metal layer when the point touches the conductive layer, and a layer signal is lost when the distance between two conductive layers is insufficient, as shown in the waveform diagram shown in fig. 7, the tool tip 110 is not disconnected with the current conductive layer, and is already in contact with the next conductive layer of the current conductive layer, so that the triggering time of the next conductive layer and the tool tip 110 cannot be determined, and the next conductive layer cannot be separated from the current conductive layer, and the position information of the conductive layer at the target position cannot be accurately determined.
Because the conductive area is arranged in the cusp area 111 of the tool nose 110, and the area outside the cusp area 111 of the tool nose 110 is insulated from the tool body 120 of the tool 100, the cusp area 111 of the tool nose 110 can be contacted with the current conductive layer only when the current conductive layer is drilled, and once the current conductive layer is drilled, the cusp area 111 of the tool nose 110 can be separated from the current conductive layer, so that the possibility that the tool 100 is not disconnected with the current conductive layer but is contacted with the next conductive layer of the current conductive layer is reduced, and the accuracy of measuring the position information of the conductive layer is improved. Wherein the axial height of the region defining the apex of the tip 110 is no greater than 0.5 mm.
Referring to fig. 2, 3 and 5, in one embodiment, the knife tip 110 is electrically connected to the handle 130 of the tool 100, and the handle 130 is electrically connected to the electrical unit.
Specifically, the electric unit refers to other components in the circuit, and the collection plate is electrically connected with the handle 130 through the electric unit, and when the knife tip 110 contacts the conductive layer, the knife tip 110 is conducted with the handle 130, so that a loop can be formed, the collection plate can collect signals, and the electric unit is not limited in this embodiment.
Further, the cutting tool 100 is made of a metal material and is integrally molded, and the regions other than the pointed region 111 of the cutting edge 110 and the shank 130 are subjected to an insulating treatment, for example, plating with an insulating material or the like. In other embodiments, the tool 100 may be formed by splicing a conductive material and a non-conductive material, as long as the tool shank 130 of the tool 100 is electrically conductive and conductive with the pointed region 111 of the tool tip 110.
Referring to fig. 2 and 3, an embodiment of the present invention further provides a tool 100, where the tool 100 is used to implement the above-mentioned back drilling method, the outer circumferential surface of the tool 100 is wrapped with an insulating coating, and areas outside the insulating coating form conductive areas.
Specifically, the cutter 100 has the conductive area, so that when the cutter 100 is conducted with the conductive layer in the sheet material 200 to form a loop in the drilling process of the cutter 100, the position information of the conductive layer at the target position in the sheet material 200 can be obtained. In the application, through once drilling, the through hole 250 drilling is realized, and the measurement of the position information of the target position conducting layer is realized, so that the whole measuring process is simple and convenient, and the back drilling efficiency is improved. Simultaneously, cutter 100 in this application can accurately switch on with current layer conducting layer to through the positional information of the conducting layer of signal of telecommunication definite target location, make when back boring, can accurate control cutter 100 drilling depth, thereby can accurately bore and remove the heavy copper of unnecessary via hole, and avoid the interior walking line of through-hole 250 to be bored absolutely, improve signal transmission quality.
Referring to fig. 3, in one embodiment, the cutting tool 100 includes a tip 110 having a tapered configuration and a body 120 having a cylindrical configuration.
Specifically, the conductive area is located in the cusp area 111 of the tip 110 in a tapered configuration, so that the possibility that the tool 100 is already in contact with a conductive layer next to the current conductive layer without being disconnected from the current conductive layer can be reduced, and the accuracy of measuring the position information of the conductive layer can be improved.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A back drilling processing method is characterized by comprising the following steps:
drilling a through hole in the plate along the thickness direction of the plate, and determining the position of a conductive layer according to the movement distance of a cutter when the conductive region of the cutter is in contact conduction with the conductive layer at a target position on the plate in the drilling process;
plating a conductive material on the wall of the through hole;
determining the area of the conductive layer, from which the conductive material of the via hole is required to be removed;
and removing the through hole sinking conductive material of the conductive layer according to the position of the conductive layer.
2. The backdrilling method of claim 1, wherein the conductive region is disposed at a tip of the tool, and a body of the tool is insulated.
3. The backdrilling method according to claim 1 or 2, wherein the conductive region is provided in a cusp region of a tip, and a region of the tip other than the cusp region is insulated from a blade body of the tool.
4. The back-drilling machining method of claim 3, wherein the sharp point region is in communication with a shank of the tool, the shank being electrically connected to an electrical unit.
5. The back-drilling processing method according to claim 1, wherein in the step "drilling a through hole in the sheet material along the thickness direction of the sheet material, and determining the position of the conductive layer according to the movement distance of the cutter when the conductive region of the cutter is in contact conduction with the conductive layer at the target position on the sheet material during the drilling process", the method further comprises:
when the conductive area of the cutter is in contact conduction with the conductive layer of the target position, the acquisition board outputs a pulse signal, and the movement distance of the cutter is fed back through the detector to determine the current position information of the conductive layer.
6. The back-drilling processing method according to claim 5, wherein the method for determining the current position information of the conductive layer by feeding back the movement distance of the tool by the detector comprises the following steps:
and feeding back the position information of the initial position of the cutter through the detector, and feeding back the position information of the cutter when the pulse signal is generated through the detector, so as to obtain the current position information of the conducting layer.
7. The backdrilling process of claim 1, wherein in the step of "after the conductive material is deposited to remove the via of the conductive layer", the method further comprises:
the tool is moved to the conductive layer nearest the copper plated area where electrical connection is desired.
8. The back-drilling machining method according to any one of claims 1 to 7, wherein the outer periphery of the blade of the tool is provided with a plurality of helical chip flutes.
9. A tool for carrying out the backdrilling method according to any one of claims 1 to 8, wherein the outer peripheral surface of the tool is coated with an insulating coating, and the region other than the insulating coating forms the conductive region.
10. The tool according to claim 9, wherein the tool comprises a tip having a conical configuration and a blade having a cylindrical configuration.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210333256.9A CN114630498A (en) | 2022-03-31 | 2022-03-31 | Back drilling method and tool |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210333256.9A CN114630498A (en) | 2022-03-31 | 2022-03-31 | Back drilling method and tool |
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| CN202210333256.9A Pending CN114630498A (en) | 2022-03-31 | 2022-03-31 | Back drilling method and tool |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN117279196A (en) * | 2023-11-17 | 2023-12-22 | 深圳市大族数控科技股份有限公司 | Circuit board, circuit board drilling device and circuit board drilling method |
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| US20140301797A1 (en) * | 2013-03-19 | 2014-10-09 | Skybrain Vermogensverwaltungs Gmbh | Device and a Method for Machining Printed Circuit Boards |
| CN107920423A (en) * | 2017-11-21 | 2018-04-17 | 大族激光科技产业集团股份有限公司 | Drilling machine and drilling production method |
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| US20140301797A1 (en) * | 2013-03-19 | 2014-10-09 | Skybrain Vermogensverwaltungs Gmbh | Device and a Method for Machining Printed Circuit Boards |
| CN103433969A (en) * | 2013-08-28 | 2013-12-11 | 华为技术有限公司 | Drilling method and device of a printed circuit board |
| CN107920423A (en) * | 2017-11-21 | 2018-04-17 | 大族激光科技产业集团股份有限公司 | Drilling machine and drilling production method |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN117279196A (en) * | 2023-11-17 | 2023-12-22 | 深圳市大族数控科技股份有限公司 | Circuit board, circuit board drilling device and circuit board drilling method |
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