CN217884001U - PCB back drilling cover plate and numerical control drilling machine system - Google Patents

Abstract

The application provides a PCB back drilling apron and numerical control rig system relates to PCB back drilling technical field. The PCB back drilling cover plate comprises a single-sided metal-clad plate and a conductive adhesive tape positioned at the edge of at least one edge of the single-sided metal-clad plate; the single-sided metal-clad plate comprises a conductive metal layer and an insulating functional layer; the conductive adhesive tape is U-shaped to coat the upper surface, the side surface and the lower surface of the single-side coated metal plate. The numerical control drilling machine system comprises the PCB back drilling cover plate, a PCB, a workbench and a drilling machine; the PCB back drilling machine comprises a PCB, a workbench, a drilling machine and a drill bit, wherein the PCB is provided with a back drilling cover plate, the back drilling cover plate is arranged on the workbench, the workbench is used for bearing the PCB, and the drilling machine drills holes on the PCB through the drill bit. When the PCB back drilling cover plate is used for back drilling, the production efficiency can be greatly improved, the risk of uncontrollable factors of manual operation is reduced, and the stability of a product in process application is improved.

Description

PCB back drilling cover plate and numerical control drilling machine system

Technical Field

The application relates to the technical field of PCB back drilling, in particular to a PCB back drilling cover plate and a numerical control drilling machine system.

Background

PCB (Printed Circuit Board), the chinese name of which is Printed Circuit Board, is called "Printed" Circuit Board because it is manufactured by electronic printing. The PCB is an important electronic component, a support for electronic components, and a carrier for electrical interconnection of electronic components. The PCB back drilling technology generally uses a high-precision drilling machine with a current sensing function to perform back drilling. In the back drilling process, the cover plate usually adopted at present is an aluminum sheet, a single-sided copper-clad plate, a phenolic aldehyde aluminum clad plate, a single-sided aluminum clad plate and the like. The aluminum sheet is adopted for back drilling and drilling, the cost is low, the surface of the aluminum sheet is smooth, the aluminum sheet is easy to slip when entering a drill, the positioning effect is poor, the hole site precision is low, the product is thin, the phenomenon of insufficient adhesion degree with a PCB (printed circuit board) exists, the drilling precision control can be influenced, meanwhile, the conductive layer of the aluminum sheet is thick (0.14-0.20 mm) and the thickness tolerance is large, the back drilling depth control precision is poor, and the aluminum sheet is gradually eliminated by the market. The single-sided copper-clad plate is adopted, the upper surface layer is the resin insulating medium layer, a drilling needle is easy to drill, the positioning effect is good, the hole position precision is high, the metal conducting layer of the copper foil is thin (not more than 35 mu m), the thickness tolerance is small, the adhesion degree of a product and a PCB (printed circuit board) is good, the drilling depth control precision is good, the cost is too high, the cost is multiple price of an aluminum sheet and is difficult to accept by a user, and meanwhile, the glass fiber in the epoxy resin glass fiber composite insulating medium layer is not beneficial to the abrasion of the drilling needle. The phenolic aluminum clad plate product overcomes the defect of high cost of a single-sided copper clad plate by using the material advantage.

However, in the prior art, one or more insulating layers are formed on the surfaces of products such as a single-sided copper-clad plate, a single-sided aluminum-clad plate and the like, and when a conductive clip (mushroom head) of a drilling machine is pressed down through the action of a cylinder, the conductive clip joint and a conductive metal layer arranged below the insulating layer cannot be in direct contact to form circuit conduction. In current practice, an operator is often required to manually place a bent metal sheet or wire with one end below the metal conductive layer and the other end on the front insulating layer. The other end of the metal sheet is pressed down and fixed by the conductive clamp built-in cylinder and is attached above the insulating layer. This kind of way needs on-the-spot manual operation action, influences the work ageing, occasionally can take place the offset that the sheetmetal was placed in the manual operation at this in-process moreover, perhaps is the vibration of drilling machine work for the sheetmetal is become flexible gradually, the slippage, thereby leads to the back drilling to bore the accuse deep precision deviation, makes the drilling quality on the PCB board have the risk, causes the product unstable.

SUMMERY OF THE UTILITY MODEL

In view of this, the present application provides a PCB back drilling cover plate and a numerical control drilling machine system to overcome the defects in the prior art, so as to solve the problem of inconvenient operation of the conductive clip in the current operation.

The application provides the following technical scheme:

a PCB back drilling cover plate comprises a single-side metal-clad plate and a conductive adhesive tape positioned at the edge of at least one edge of the single-side metal-clad plate;

the single-sided metal-clad plate comprises a conductive metal layer and an insulating functional layer covering the conductive metal layer;

the conductive adhesive tape is U-shaped to coat the upper surface, the side surface and the lower surface of the single-sided metal-clad plate.

Preferably, the conductive adhesive tape comprises a conductive base material layer and a conductive adhesive layer which are arranged in a stacked manner.

Preferably, the thickness of the conductive substrate layer is 0.002mm-1mm, and the thickness of the conductive adhesive layer is 0.002mm-0.5mm.

Preferably, the material of the conductive substrate layer is a material having a conductive function, and specifically may include: metal foil, conductive polymer film, conductive paper, conductive cloth, conductive fiber, conductive rubber, conductive plastic, graphene, carbon-based material, etc., and is not limited to the materials listed herein.

Preferably, the conductive adhesive tape extends along the side length direction of the single-side metal-clad plate, and the length of the conductive adhesive tape is not less than 0.5mm and is not more than the side length of the single-side metal-clad plate. Further, the actual length of the conductive adhesive tape can be adjusted according to the position of the conductive clamp of the drilling machine.

Preferably, the width of the conductive adhesive tape on the upper surface and/or the lower surface of the single-side metal-clad plate is 1mm-30mm.

Preferably, the conductive adhesive tapes are distributed at intervals at the edge position of at least one edge of the single-sided metal-clad plate.

Preferably, the insulating functional layer comprises at least one insulating layer for cleaning the drill bit.

The application also provides a numerical control drilling machine system, which comprises the PCB back drilling cover plate, a PCB, a workbench and a drilling machine;

the PCB back drilling cover plate comprises a workbench, a drilling machine and a PCB board, wherein a conductive metal layer of the PCB back drilling cover plate is in contact with the PCB board, the workbench is used for bearing the PCB board, and the drilling machine is used for drilling the PCB board.

Preferably, the drill bit of the drilling machine is connected with a control system of the drilling machine through a main shaft and a first circuit of the drilling machine, the control system of the drilling machine is connected with the conductive clamp through a second circuit, and the conductive clamp is in contact with the conductive adhesive tape of the PCB back drilling cover plate.

This application has following advantage:

according to the conductive adhesive tape, the edge position of the single-side-coated metal plate is provided with the conductive adhesive tape, the conductive adhesive tape can be simultaneously connected with the upper surface and the lower surface of the single-side-coated metal plate, and the conductive metal layer of the single-side-coated metal plate can be connected with the conductive adhesive tape at the edge position of the insulating function layer to form a stable conductive path. Through this kind of institutional advancement of this application, can improve PCB back drilling technology's stability greatly, improve the stability of product in the in-process application, eliminated prior art manual operation's sheetmetal or metal wire and the electrically conductive risk that drops that becomes flexible between pressing from both sides of drilling machine.

The PCB back drilling cover plate provided by the application is used in the numerical control drilling machine system, the production efficiency of PCB back drilling can be greatly improved, the risk of uncontrollable factors of manual operation is reduced, and the reliability and stability of a PCB product prepared by a back drilling process are improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Figure 1 shows a schematic diagram of a PCB backdrilling cover plate of example 1;

fig. 2 shows a schematic cross-sectional view of a PCB back-drilled cover plate of embodiment 1;

FIG. 3 shows a schematic diagram of a PCB back-drilled cover plate of some other embodiments;

FIG. 4 shows a PCB back-drilled cover plate schematic of example 2;

figure 5 shows a schematic cross-sectional view of a PCB back-drilled cover plate of example 2;

FIG. 6 shows a schematic view of a numerically controlled drilling rig system of embodiment 3.

Description of the main element symbols:

1-PCB back drilling cover plate; 11-coating a metal plate on one side; 12-a conductive adhesive tape; 1101-a conductive metal layer; 1102-an insulating functional layer; 1103-a phenolic resin layer; 1104-a fiberboard layer; 1201-a conductive substrate layer; 1202-a conductive adhesive layer;

2-a PCB board;

3-a workbench;

4-a drilling machine; 41-drilling machine main shaft; 42-a drill bit; 43-first line; 44-a driller control system; 45-a second line; 46-conductive clip.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are exemplary only for explaining the present invention, and should not be construed as limiting the present invention.

It will be understood that when an element is referred to as being "secured to" 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. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

In the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly, e.g., as being fixedly connected, detachably connected, or integrated; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or may be connected through the use of two elements or the interaction of two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

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 one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the templates herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Example 1

As shown in fig. 1, the PCB back-drill cover plate 1 of the present embodiment includes a single-sided metal-clad plate 11 and a conductive adhesive tape 12 located at an edge of one side of the single-sided metal-clad plate.

As shown in the cross-sectional schematic diagram of fig. 2, the single-sided metal-clad plate 11 of the PCB back-drilled cover plate 1 includes a conductive metal layer 1101 and an insulating functional layer 1102 covering the conductive metal layer 1101; the conductive adhesive tape 12 is U-shaped to cover the upper surface, the side surface and the lower surface of the single-sided metal-clad plate 11. That is, at the edge position of the single-sided metal-clad plate 11, the conductive rubber strip 12 is U-shaped and covers the insulating functional layer 1102 and the conductive metal layer 1101.

The shape of the single-sided metal-clad plate 11 is not particularly limited, and may be a circle, a triangle, a quadrangle, a regular polygon, or an irregular polygon.

Taking the single-sided metal-clad plate 11 as a quadrilateral plate as an example, the conductive adhesive tape 12 may be disposed at an edge of any one side of the quadrilateral as in this embodiment. In other embodiments, the conductive adhesive tape may be disposed at the edge positions of any two sides of the quadrangle, at the edge positions of any three sides, or at the edge positions of all four sides, as shown in fig. 3.

The conductive metal layer 1101 of the single-sided metal-clad plate 11 of this embodiment is an aluminum foil, and in other embodiments, the material of the conductive metal layer may also be a copper foil or other metal material.

The insulating functional layer 1102 of this embodiment is an insulating layer for cleaning the drill bit, and the insulating layer may be made of phenolic resin or epoxy resin glass fiber composite material.

Regarding the thicknesses of the insulating functional layer 1102 and the conductive metal layer 1101, the present application is not particularly limited, and the thickness commonly used in the prior art may be used, for example, the thickness of the conductive metal layer 1101 is 0.02mm, and the thickness of the insulating functional layer 1102 is 0.4mm. Through the collocation of insulating functional layer 1102 and conducting metal layer 1101, can make PCB back drill apron 1 as the auxiliary material of PCB drilling man-hour, can protect PCB panel surface better, can also fix the drill bit, the range of swaying, the skew of drill bit when reducing the drilling makes the drill bit pinpoint, improves the hole site precision, clears away the impurity on the drill bit, assists the drill bit to give off the heat, reduces the drill bit temperature, reduces the wearing and tearing and the disconnected brill etc. of drill bit.

The conductive adhesive tape 12 of this embodiment includes a conductive base material layer 1201 and a conductive adhesive layer 1202, and the conductive adhesive layer 1202 is adhered to the single-sided metal-clad plate 11.

Specifically, the conductive substrate layer 1201 may be a metal foil, a conductive polymer film, conductive paper, conductive cloth, or conductive fiber, wherein the metal foil may be an aluminum foil, a copper foil, or a tin foil; the conductive adhesive layer 1202 may be selected to be an adhesive having a conductive function.

The conductive adhesive tape is formed by combining a conductive material and conductive adhesive in an up-and-down laminated manner, so that double-sided conduction of the adhesive tape is realized, and the conductive adhesive tape can be coated and adhered to the edge position of a single-sided metal-coated plate by using a conductive adhesive layer after being bent by manual operation or edge covering machine operation.

The conductive adhesive tape 12 is U-shaped and simultaneously adheres to the insulating functional layer 1102 of the single-sided metal-clad plate, the conductive metal layer 1101 and the side surface of the edge of the single-sided metal-clad plate 11, so that the metal in the conductive metal layer and the conductive adhesive tape on the insulating functional layer form a stable conductive path connection.

In some embodiments of the present application, the thickness of the conductive substrate layer 1201 on the strip 12 is 0.002mm to 1mm, such as 0.002mm, 0.01mm, 0.05mm, 0.1mm, 0.5mm, 1mm or any value between 0.002mm and 1mm, and the thickness of the conductive adhesive layer 1202 is 0.002mm to 0.5mm, such as 0.002mm, 0.01mm, 0.05mm, 0.1mm, 0.5mm or any value between 0.002mm and 1mm.

In this embodiment, the thickness of the conductive base material layer 1201 on the conductive adhesive tape 12 is 0.05mm, and the thickness of the conductive adhesive layer 1202 is 0.1mm.

It should be noted that if the thickness of the conductive substrate layer is too thick, the conductive substrate layer is difficult to bend, the conductive adhesive tape cannot be tightly attached effectively, and the preparation cost of the material is increased when the thickness is increased; the thickness of the conductive adhesive layer is not too thick, otherwise the resistance of the conductive adhesive tape is increased, and the induced current of the subsequent back drilling process is influenced.

When the material selection and the thickness selection are performed on the conductive adhesive layer and the conductive base material layer, the resistance of the conductive adhesive tape finally formed by combination is considered. If electrically conductive adhesive tape resistance is too big, when can leading to holing this PCB back drilling apron on the PCB panel, the electric current that the drill bit of drilling machine passes through PCB back drilling apron and electrically conductive joint clip and drilling machine internal circuit formation electric current route is less, and drilling machine control system can not effectively sense the electric current, just also can't control the drilling machine and carry out relevant drilling task. Therefore, the resistance of the path between the conductive adhesive tape 12 and the single-side metal-clad plate 11 is required to be less than or equal to 2 omega; the path consists of a conductive base material layer 1201 of a conductive adhesive tape, a conductive adhesive layer 1202 and a conductive metal layer 1101 with a metal plate covered on one side; the resistance requirement when forming a complete path with a drilling machine is from a current sensing depth control function device of the drilling machine, and the resistance of the whole current sensing path is required to be less than or equal to 5 omega.

In some embodiments of the present application, the conductive rubber strip 12 extends along a side length of the single-sided metal-clad plate 11, and a length L of the conductive rubber strip 12 is not less than 0.5mm and does not exceed the side length of the single-sided metal-clad plate 11. Further, the actual length of the conductive adhesive tape 12 can be adjusted according to the position of the conductive clip of the drilling machine, so as to ensure that the contact can be realized and the conduction can be carried out.

The width W of the conductive adhesive tape 12 on the upper surface and/or the lower surface of the single-sided metal-clad plate 11 is 1mm to 30mm, and may be, for example, 1mm, 5mm, 10mm, 15mm, 20mm, 30mm, or any value between 1mm and 30mm.

It should be noted that the width of the conductive adhesive tape 12 on the upper surface and the width on the lower surface of the single-sided metal-clad plate 11 may be completely the same or different, and the specific value is only required to be within the range of 1mm to 30mm. Therefore, the conductive clip in the numerical control drilling machine system can have enough contact area with the conductive adhesive tape, and the circuit conduction is realized.

In this embodiment, the PCB back-drilling cover plate 1 is a 40cm-60cm rectangular plate, wherein the conductive adhesive tape 12 is at the edge of one side of the cover plate with a side length of 40cm, the length of the conductive adhesive tape 12 is 30cm, and the widths of the upper surface and the lower surface of the single-side metal-clad plate 11 of the conductive adhesive tape 12 are the same, and are both 10mm.

Example 2

As shown in fig. 4, the PCB back-drilling cover plate 1 of the present embodiment includes a single-sided metal-clad plate 11 and a plurality of conductive adhesive strips 12 located at an edge of one side of the single-sided metal-clad plate, and the conductive adhesive strips are distributed at intervals.

As shown in the schematic cross-sectional structure diagram of fig. 5, the single-sided metal-clad plate 11 includes a conductive metal layer 1101 and an insulating functional layer covering the conductive metal layer, and the insulating functional layer specifically includes a phenolic resin layer 1103 and a fiber board layer 1104 that are sequentially stacked. In other embodiments, additional functional insulating layers may be disposed over the fiber board layer 1104, such as a buffer dielectric layer. Through set up the different insulating functional layer of multilayer on conductive metal layer, clean drill bit that can be better, also can ensure the planarization of PCB back drilling apron, it is inseparabler to make it laminate with the PCB board, it is high to improve the dark precision of drilling accuse, and can also be through setting up the different insulating functional layer of multilayer of hardness, make the drill bit when contacting PCB back drilling apron, have certain cushioning effect, be unlikely to because hardness is too big, lead to producing the resistance to the drill bit, and then produce disconnected needle or drilling off normal.

The conductive adhesive tape 12 of the present embodiment also includes a conductive base material layer 1201 and a conductive adhesive layer 1202, and covers the upper surface, the side surface, and the lower surface of the single-sided metal-clad plate 11 in a U shape.

The distance of the plurality of conductive adhesive strips 12 at the edge is not particularly limited, and the conductive adhesive strips can be finely designed according to the positions of the conductive clips in the specific back drilling process, and can be distributed at equal intervals or randomly distributed at intervals. The length and width of each strip 12 may be the same or different.

In this embodiment, 3 conductive adhesive tapes 12 are disposed at an edge of one edge of the single-sided metal-clad plate 11, each conductive adhesive tape has a length of 50mm extending along the length of the single-sided metal-clad plate, and widths of the upper surface and the lower surface of the single-sided metal-clad plate are the same, specifically 15mm.

The conductive clamp of the drilling machine with different brands is designed at different positions on the working table. There are also 2 redundant designs of conductive clips for individual brand drills. In contrast, the plurality of conductive adhesive tapes 12 are arranged at the edge of one edge of the single-sided metal-clad plate, mainly considering the difference of the positions of the conductive clips on the worktable of the drilling machine. Ensuring that each conductive clip can be in full contact with the strip of conductive adhesive. The single-sided metal-clad plate and the PCB are fixed to a certain extent, and compared with the method that the conductive adhesive tape is arranged on the whole edge, the cost of a part of the method can be reduced, the conductive clamp, the single-sided metal-clad plate and the drill bit can form a stable current path when back drilling is carried out, the reliability of circuit connection is effectively improved, and the purpose that the PCB back drilling requires accurate depth control drilling is further achieved.

Example 3

The PCB back-drilled cover plate of this embodiment is the same as embodiment 1. The embodiment also provides a numerical control drilling machine system which comprises a PCB back drilling cover plate 1, a PCB 2, a workbench 3 and a drilling machine 4, as shown in FIG. 6.

The conductive metal layer 1101 of the PCB back-drilled cover plate 1 is in contact with the PCB 2, the workbench 3 is used for bearing the PCB 2, and the drilling machine 4 is used for drilling the PCB 2.

The drill bit 42 of the drilling machine 4 is connected with a drilling machine control system 44 through a drilling machine spindle 41 and a first line 43, the drilling machine control system 44 is connected with a conductive clip 46 through a second line 45, and the conductive clip 46 is in contact with the conductive rubber strip 12 of the PCB back drilling cover plate 1.

Before the drilling machine is started, it is necessary to ensure that the PCB back-drilling cover plate 1 and the PCB 2 are stacked on the worktable 3 in sequence from top to bottom.

After the drilling machine 4 is started, the conductive clip 46 is started to be pressed downwards, so that the conductive clip is contacted with the conductive adhesive tape 12 at the edge position of the PCB back drilling cover plate 1, and the PCB back drilling cover plate 1 and the PCB plate 2 are pressed and fixed at the same time. The operator then sets the desired drilling depth on the PCB board via the drill control system 44. Before drilling, a circuit path is not formed between the drilling machine control system 44 and the drilling machine spindle 41, the PCB back drilling cover plate 1 and the PCB 2, and the drilling machine control system cannot receive a feedback current signal.

The main shaft 41 of the drilling machine starts to drill down to the PCB back drilling cover plate 1, the drill bit 42 firstly contacts with the insulating functional layer 1102 of the single-side metal-clad plate 11 and continues to drill downwards, the drill point of the drill bit 42 contacts with the conductive metal layer 1101 of the single-side metal-clad plate 11, and at the moment, the drill bit 42, the main shaft 41 of the drilling machine, the first line 43, the control system 44 of the drilling machine, the second line 45, the conductive clip 46, the conductive tape 12, the conductive metal layer 1101 and the PCB 2 all have a conductive function and can form a circuit path. The driller control system 44 receives the feedback current signal, confirms the position of the drill 42 on the surface layer of the PCB board, and continues to drill to the depth point required by the setting at the position, thereby achieving the purpose of accurately controlling the depth drilling required by the PCB back drilling.

Comparative example 1

The PCB backdrilling cover plate of the present comparative example is a single-sided metal-clad plate, which includes a conductive metal layer and an insulating functional layer.

The comparative example also provides a numerical control drilling machine system which comprises the PCB back drilling cover plate, the PCB, the workbench, the metal sheet and the drilling machine of the comparative example. The drill bit of the drilling machine is connected with the drilling machine control system through the main shaft of the drilling machine and the first circuit, and the drilling machine control system is connected with the conductive clamp through the second circuit.

Before the drilling machine is started, the conductive metal layer of the PCB back drilling cover plate is contacted with the PCB and placed on a workbench, then an operator manually folds the metal sheet into a V shape, one edge of the V-shaped metal sheet is inserted between the conductive metal layer of the single-side metal-clad plate and the PCB, and the other edge of the V-shaped metal sheet is contacted with the insulating function layer of the single-side metal-clad plate. That is, the operator clamps the V-shaped metal sheets on the upper and lower surfaces at the edge of the single-sided metal-clad sheet by manual operation.

After the drilling machine is started, the switch of the conductive clamp is started firstly, the conductive clamp is pressed downwards to press the PCB back drilling cover plate and the PCB, and meanwhile an operator is required to ensure that the conductive clamp is in contact with a metal sheet at the edge of the PCB back drilling cover plate, so that a conductive metal layer of the single-surface metal-coated plate, the metal sheet and the conductive clamp on the drilling machine are in conductive connection.

And then, an operator sets the required drilling depth on the PCB through the drilling machine control system, then operates the drilling machine to enable the drill bit to gradually drill downwards and contact the insulating functional layer of the PCB back drilling cover plate, and continues to drill downwards, the drill point of the drill bit can contact the conductive metal layer of the PCB back drilling cover plate, and at the moment, a circuit path is formed among the drill bit, the drilling machine main shaft, the first circuit, the drilling machine control system, the second circuit, the conductive clamp, the metal sheet and the conductive metal layer. And the drilling machine control system receives the feedback current signal, confirms that the drill bit is positioned on the surface layer of the PCB, and then continues to drill to a depth point required by setting, so that the purpose of accurately controlling the depth drilling required by PCB back drilling is achieved.

The PCB back drilling cover plate and the numerical control drilling machine system of the embodiment 3 and the comparative example 1 can realize back drilling and drilling of the PCB. However, in the actual production operation, a drilling machine is provided with an operator as an example: by using the PCB back-drilling cover plate of embodiment 3 of the present application, an operator only needs to place the PCB and the PCB back-drilling cover plate on the workbench, observe the pressing position of the conductive clip through eyes after the switch of the conductive clip is turned on, ensure that the conductive clip is in contact with the conductive adhesive tape, fix the PCB back-drilling cover plate, complete the preparation work before drilling, and then drill holes; the preparation time before drilling is approximately 5 minutes. When the PCB back-drilling cover plate of the comparative example 1 is used, after an operator places the PCB board and the PCB back-drilling cover plate on the workbench, the operator also takes out the metal strip, folds the metal strip into a V shape and clamps the metal strip on the upper surface and the lower surface of the edge of the PCB back-drilling cover plate, then starts the conductive clip switch, and if the pressing position of the conductive clip has a certain deviation from the metal strip, manually moves the position of the metal sheet or electrically controls the position of the conductive clip, so that the conductive clip can be pressed on the metal sheet finally, and then fixes the PCB back-drilling cover plate to complete the preparation work before drilling; the preparation time before this drilling is about 10 minutes.

In addition, taking a large-scale factory as an example, 30 drilling machines are used for back drilling, each drilling machine needs to complete 20 processing cycles of PCB back drilling every day, and the PCB back drilling cover plate of the embodiment 3 and the comparative example 1 of the present application are used for testing respectively. After statistics, the following results are found: at completion time, using the PCB back drill cover plate of the present application, the processing time for each drill to complete 20 processing cycles per day was about 90-100 minutes earlier than the completion time of comparative example 1. In the finishing quality, in comparative example 1, because of manual operation, the situation that the back drill hole is scrapped because of 2 times of manual misoperation occurs in 1 month, and the metal sheet gradually loosens and falls off, and the similar situation does not occur when the PCB back drill cover plate of the embodiment 3 of the application is used.

Therefore, this application sets up conducting strip through lapping edge in PCB back drilling, has replaced the function of sheetmetal among the prior art, wherein because there is the existence of conducting adhesive adhesion coating in the conducting strip, can ensure to lead stable connection between adhesive strip and the single face cladding metal sheet, has eliminated the manual work and has placed sheetmetal (line) and lead and take place not hard up, the risk that drops between the conductive clamp. Therefore, the operation flow of the drilling machine during drilling can be reduced, the working efficiency is greatly improved, the drilling precision is also improved, the deviation of the back drilling depth control precision caused by the slippage of the metal sheet due to the deviation of the conductive clamp and the vibration of the drilling machine is reduced, and the reliability of a PCB drilling product is improved.

In all examples shown and described herein, any particular value should be construed as exemplary only and not as a limitation, and thus other examples of example embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined or explained in subsequent figures.

The above-described embodiments are merely illustrative of several embodiments of the present invention, which are described in detail and specific, but not intended to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the concept of the present invention, several variations and modifications can be made, which all fall within the scope of the present invention.

Claims (10)

1. A PCB back drilling cover plate is characterized by comprising a single-side metal-clad plate and a conductive adhesive tape positioned at the edge of at least one edge of the single-side metal-clad plate;

the single-sided metal-clad plate comprises a conductive metal layer and an insulating functional layer covering the conductive metal layer;

the conductive adhesive tape is U-shaped to coat the upper surface, the side surface and the lower surface of the single-sided metal-clad plate.

2. The PCB back-drilling cover plate of claim 1, wherein the conductive adhesive tape comprises a conductive substrate layer and a conductive adhesive layer which are stacked.

3. The PCB back-drilling cover plate of claim 2, wherein the thickness of the conductive substrate layer is 0.002mm-1mm, and the thickness of the conductive adhesive layer is 0.002mm-0.5mm.

4. The PCB back-drilling cover plate of claim 2, wherein the material of the conductive substrate layer is a material with a conductive function.

5. The PCB back-drilling cover plate of claim 1, wherein the conductive adhesive tape extends along the length of the side of the single-sided metal-clad plate, and the length of the conductive adhesive tape is not less than 0.5mm and does not exceed the length of the side of the single-sided metal-clad plate.

6. The PCB back-drilling cover plate of claim 1, wherein the width of the conductive adhesive tape on the upper surface and/or the lower surface of the single-sided metal-clad plate is 1mm-30mm.

7. The PCB back-drilling cover plate of claim 1, wherein the conductive adhesive strips are distributed at intervals at the edge position of at least one edge of the single-sided metal-clad plate.

8. The PCB back-drilling cover plate of any one of claims 1 to 7, wherein the insulating functional layer comprises at least one insulating layer for cleaning a drill bit.

9. A numerical control drilling system comprising the PCB back drill cover plate, the PCB board, the table and the drilling machine of any one of claims 1 to 8;

the PCB back drilling cover plate comprises a PCB, a workbench and a drilling machine, wherein the PCB is provided with a conductive metal layer, the conductive metal layer is arranged on the PCB, the workbench is used for bearing the PCB, and the drilling machine is used for drilling the PCB.

10. The numerical control drilling machine system according to claim 9, wherein a drill bit of the drilling machine is connected with a drilling machine control system through a main shaft of the drilling machine and a first line, the drilling machine control system is connected with a conductive clip through a second line, and the conductive clip is in contact with the conductive rubber strip of the PCB back drilling cover plate.

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