CN115243466A - A kind of depth control drilling tool and PCB back drilling depth control method - Google Patents

Abstract

The invention relates to the technical field of PCBs (printed circuit boards), and discloses a depth control drill and a PCB back drilling depth control method. The depth control drill comprises a drill handle, a drill neck and a cutter body, wherein the cutter body comprises a guide part and a drill tip; the depth-control drilling tool also comprises a baffle part; the blocking part is arranged at a preset height position on the drill neck or the cutter body, so that the length of the cutter body between the bottom surface of the blocking part and the end surface of the drill tip is the target drilling depth, and the projection of the blocking part on the back drilling surface of the PCB is not overlapped with the corresponding back drilling hole in the back drilling working state. According to the embodiment of the invention, when the partition part moves downwards along with the cutter body to the height position of the back drilling surface of the PCB, the partition part can be abutted against the back drilling surface, so that the cutter body is prevented from moving downwards continuously, and the actual drilling depth of the cutter body in the PCB is the vertical distance between the bottom surface of the partition part and the end surface of the drill point, namely the preset target drilling depth. Therefore, the invention can simply and accurately control the back drilling depth to reach the target drilling depth.

Description

A kind of depth control drilling tool and PCB back drilling depth control method

technical field

The invention relates to the technical field of PCB (Printed Circuit Boards, printed circuit boards), in particular to a depth-controlling drill and a depth-controlling method for PCB back drilling.

Background technique

With the development of 5G wireless network technology, communication products have higher and higher requirements for high frequency and high speed of PCB. In the PCB manufacturing process, since the purpose of back drilling is to "remove redundant copper holes in the signal layer of metallized through holes, reduce signal loss and avoid signal distortion", back drilling has become a key process in the circuit board manufacturing process. In this key process, how to improve the control accuracy of the back drilling depth is particularly critical. However, high-precision back drilling depth control has not yet been achieved.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a depth-controlling drill and a method for controlling the depth of PCB back-drilling, so as to overcome the defect of the low-precision back-drilling depth control existing in the prior art.

For this purpose, the present invention adopts the following technical solutions:

A depth-controlling drill, comprising a drill shank, a drill neck and a cutter body arranged in sequence along a length direction, the cutter body comprising a guide portion and a drill tip, and the guide portion is connected between the drill neck and the drill tip, so that the The control depth drill also includes a partition;

The partition portion is installed at a preset height position on the drill neck or the cutter body, so that the length of the portion of the cutter body located between the bottom surface of the partition portion and the drill tip surface is the target drilling depth, and in the back-drilling working state The projections of the partitions described below on the back-drilled drilling surface of the PCB do not coincide with the corresponding back-drilled holes.

Optionally, the baffle portion includes a body and a contact portion disposed at the bottom of the body;

The contact portion is used for electrical connection with the conductive layer of the back-drilled surface of the PCB, or contact with the pressure sensor of the back-drilled surface of the PCB.

Optionally, the body is sleeved on the drill neck or the outer periphery of the guide portion.

Optionally, the contact portion is protruded from the bottom surface of the body, and a predetermined gap is formed between the contact portion and the guide portion.

Optionally, the contact portion is an integrally formed hollow structure with a flat contact surface, uniformly surrounding the outer periphery of the guide portion.

Optionally, the outer side of the guide portion is provided with at least two installation positions along its length direction, and each installation position corresponds to a different target drilling depth;

The baffle portion is detachably installed at an installation position corresponding to the current target drilling depth.

A method for controlling the depth of PCB back drilling, comprising:

Provide PCBs with metallized through holes;

Using the depth-controlling drill as described in any one of the above, at the corresponding position of the metallized through hole, back-drilling is started from the back-drilling surface of the PCB;

When it is recognized that the partition portion descends to come into contact with the back-drilling drilling surface of the PCB, the depth-controlling drill is controlled to stop back-drilling.

Optionally, the back-drilling surface of the PCB is provided with a conductive layer; the baffle part includes a body and a contact part provided at the bottom of the body, and the contact part is used for conducting electricity with the back-drilling surface of the PCB. Layer contact electrical connection;

The method for identifying whether the partition portion descends to be in contact with the back-drilling surface of the PCB includes: during the drilling process, detecting the electrical conduction state between the contact portion and the conductive layer in real time, When the electrical conduction state is switched from open circuit to short circuit, it is determined that the baffle portion has descended to contact with the back drilling surface of the PCB.

Optionally, a pressure sensor is provided on the projection position of the back-drilling drill surface of the PCB at the partition portion; the partition portion includes a main body and a contact portion provided at the bottom of the main body; the contact portion is used for Contact with the pressure sensor on the back-drilled surface of the PCB;

The method for identifying whether the partition portion descends to contact with the back drilling surface of the PCB comprises: detecting the pressure value of the pressure sensor in real time, and determining that the partition portion has descended when the pressure value increases sharply to make contact with the back-drilled surface of the PCB.

Optionally, the back-drilling surface of the PCB is further provided with a protective layer.

Compared with the prior art, the beneficial effects of the present invention are:

In the embodiment of the present invention, the specific installation height of the partition portion on the drill cutter can be set according to the target drilling depth, so as to ensure that the length of the cutter body between the bottom surface of the partition portion and the drill tip surface is the target drilling depth. Since the projection of the partition part falls into the board surface area (non-back-drilling area) of the back-drilling surface of the PCB, when the partition part descends with the cutter body to the height of the back-drilling surface of the PCB, the The stopper will conflict with the back drilling surface of the PCB, thus preventing the cutter body from continuing to descend, and the actual drilling depth of the cutter body in the PCB is the vertical distance from the bottom surface of the stopper to the drill tip surface, which is the preset target drilling depth. Therefore, based on the depth-controlling drill, it is only necessary to design the installation position of the partition according to the target drilling depth, that is, the back-drilling depth can be controlled simply and accurately to reach the target drilling depth.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

FIG. 1 is a schematic structural diagram of a depth control drill provided by an embodiment of the present invention.

FIG. 2 is a schematic diagram of an application method of a depth control drill provided by an embodiment of the present invention.

FIG. 3 is a flowchart of a method for controlling depth of PCB back drilling provided by an embodiment of the present invention.

Description of reference numerals: depth control drill 1 , drill shank 11 , guide portion 12 , drill tip 13 , partition portion 14 , body 141 , contact portion 142 , PCB 2 .

Detailed ways

In order to make the purpose, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the following The described embodiments are only some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In order to improve the depth control accuracy of back drilling, an embodiment of the present invention provides a depth control drill 1, which can accurately control the depth of back drilling when applied to back drilling. Referring to FIGS. 1 and 2, the depth control drill 1 provided by the embodiment of the present invention includes: a drill shank 11, a drill neck and a cutter body arranged in sequence along the length direction, the cutter body includes a guide portion 12 and a drill tip 13, and the guide The portion 12 is connected between the drill neck and the drill tip 13 .

Among them, the drill shank 11 is the part for clamping the deep drill 1, and is used to transmit the power (torque and axial force) required for drilling; the drill neck is located between the drill shank 11 and the cutter body The transition part of the drill body, which is the working part of the depth control drill 1, is composed of the drill tip 13 (ie the cutting part) and the guide part 12.

Different from the conventional drill structure, the depth control drill 1 of the embodiment of the present invention further includes a partition portion 14, and the partition portion 14 is installed at a predetermined height position on the drill neck or the cutter body, so that the cutter body is located in the partition The length of the part between the bottom surface of the part 14 and the end surface of the drill tip 13 is the target drilling depth, and the projection of the baffle part 14 on the back drilling surface of the PCB 2 does not coincide with the corresponding back drilling in the back drilling working state.

It should be noted that, in the embodiment of the present invention, the specific installation height position of the partition portion 14 on the drill can be set according to the target drilling depth, so as to ensure that the cutter body is located between the bottom surface of the partition portion 14 and the end face of the drill tip 13 . The length is the target drilling depth. Since the projection of the baffle portion 14 falls into the board surface area (non-back-drilled area) of the back-drilling drilling surface of the PCB 2, the baffle portion 14 descends with the cutter body to the height of the back-drilling drilling surface of the PCB 2 When in position, the partition portion 14 will interfere with the back drilling surface of the PCB 2, thereby preventing the cutter body from continuing to descend, and the actual drilling depth of the cutter body in the PCB 2 is from the bottom surface of the partition portion 14 to the end face of the drill tip 13. The vertical distance between them, that is, the preset target drilling depth. Therefore, based on the depth-controlling drill 1 , it is only necessary to design the installation position of the baffle portion 14 according to the target drilling depth, that is, the back-drilling depth can be simply and accurately controlled to reach the target drilling depth.

In an optional embodiment, the baffle portion 14 includes a body 141 and a contact portion 142 provided at the bottom of the body 141 ; the contact portion 142 is used for electrical connection with the conductive layer of the back-drilled surface of the PCB 2 . , or in contact with the pressure sensor on the back-drilled surface of PCB 2.

Because when the contact portion 142 descends to contact with the conductive layer located on the back drill surface, the electrical conduction state between the contact portion 142 and the conductive layer will be switched from open circuit to short circuit; When the pressure sensor on the drilling surface contacts, the pressure detection value of the pressure sensor will surge (ie, increase rapidly). Therefore, in this embodiment, under the cooperative action of the contact portion 142 and the conductive layer/pressure sensor, it can be automatically, quickly and accurately identified whether the partition portion 14 descends with the cutter body to the back-drilling with the PCB 2 The drilling surfaces are in contact with each other, and the back drilling is automatically controlled to stop, so as to avoid damage to the PCB 2 board surface due to the continuous rotation of the depth control drill 1 after being restricted in downward movement.

The body 141 can be sleeved on the drill neck or the outer periphery of the guide portion 12, so that simple and fast assembly can be realized. The contact portion 142 is protruded from the bottom surface of the main body 141 , and a predetermined gap is formed between the contact portion 142 and the guide portion 12 . In this way, mutual interference between the contact portion 142 and the guide portion 12 can be avoided due to the tightness, and at the same time, the drilling quality and control accuracy can be ensured. Of course, in other embodiments, the body 141 may also be installed in various other conventional manners.

Exemplarily, the contact portion 142 is an integrally formed hollow structure with a flat contact surface, and is evenly arranged around the outer circumference of the guide portion 12, which can effectively improve the detection of whether the baffle portion 14 is in contact with the back drilling surface. precision.

In order to improve the versatility of the depth control drill 1, the outer side of the guide portion 12 is provided with at least two installation positions along its length direction, and each installation position corresponds to a different target drilling depth; The installation position corresponding to the target drilling depth. Based on this, before application, a matching installation position of the baffle portion 14 can be selected according to the currently set target drilling depth, so as to meet different drilling depth requirements.

Referring to FIG. 3 , an embodiment of the present invention further provides a method for controlling the depth of back drilling of PCB 2, including:

Step 101 , providing a PCB 2 with metallized through holes.

Step 102 , using the depth-controlling drill 1 , at the corresponding position of the metallized through hole, start back-drilling from the back-drilling surface of the PCB 2 .

The depth control drill 1 in this step includes: a drill shank 11, a drill neck and a cutter body arranged in sequence along the length direction, the cutter body includes a guide portion 12 and a drill tip 13, and the guide portion 12 is connected to the drill neck and the drill tip 13; also includes a baffle portion 14, the baffle portion 14 is installed at a preset height position on the drill neck or the cutter body, so that the length of the portion of the cutter body between the bottom surface of the baffle portion 14 and the end face of the drill tip 13 It is the target drilling depth, and the projection of the baffle portion 14 on the back-drilling surface of the PCB 2 does not coincide with the corresponding back-drilling hole in the back-drilling working state.

Step 103: During the back-drilling process, identify in real time whether the partition portion 14 descends to contact the back-drilling surface of the PCB 2, and if so, control the depth-controlling drill 1 to stop the back-drilling.

Compared with the conventional drill structure, the depth control drill 1 of the embodiment of the present invention further includes a partition portion 14 installed on the drill neck/blade body at a predetermined height position, and the partition portion 14 can descend to the PCB The height of the 2 board surface is the same as the PCB 2 board surface, thereby preventing the cutter body from continuing to descend. At this time, the length of the cutter body that has been drilled into the PCB 2 is the vertical distance from the bottom surface of the partition part 14 to the end surface of the drill tip 13, that is, the preset target drilling depth. Therefore, in the embodiment of the present invention, the installation position of the partition portion 14 only needs to be designed according to the target drilling depth, that is, the back drilling depth can be controlled simply and accurately to reach the target drilling depth.

In order to avoid damage to the board surface of the PCB 2 due to the continuous rotation of the depth-controlling drill 1 after the downward movement is restricted, the embodiment of the present invention provides two effective solutions to automatically identify whether the downward movement is restricted, so as to realize the rapid control of the back-drilling stop , in order to effectively reduce the adverse force exerted by the depth control drill 1 on the PCB 2 board surface.

First solution:

The back-drilling surface of the PCB 2 is provided with a conductive layer; the baffle portion 14 includes a body 141 and a contact portion 142 disposed at the bottom of the body 141, and the contact portion 142 is used for contacting the conductive layer of the back-drilling surface of the PCB 2 Electrical connection; the conductive layer can be aluminum sheet or conductive glue.

Based on this, the method for identifying whether the baffle portion 14 descends to contact with the back-drilling surface of the PCB 2 includes: during the drilling process, real-time detection of the electrical conduction state between the contact portion 142 and the conductive layer, in the electrical conduction state When switching from open circuit to short circuit, it is determined that the baffle portion 14 has descended to come into contact with the back drilling surface of the PCB 2 .

Second solution:

The back drilling surface of PCB 2 is provided with a pressure sensor at the projected position of the partition part 14; the partition part 14 includes a main body 141 and a contact part 142 arranged at the bottom of the main body 141; the contact part 142 is used for back drilling with the PCB2 Contact the pressure sensor on the drilling face.

Based on this, the method for identifying whether the baffle portion 14 has descended to contact with the back-drilling surface of the PCB 2 includes: detecting the pressure value of the pressure sensor in real time, and when the pressure value surges, determining that the baffle portion 14 has descended to contact with the back-drilling surface of the PCB 2 . The back-drilled PCB 2 is in contact with the drilled surface.

In this method, a layer of protective layer can be added to the back-drilling surface of the PCB 2 to protect the back-drilling surface.

As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand: The technical solutions described in the embodiments are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. A depth-control drilling tool comprises a drill handle (11), a drill neck and a tool body which are sequentially arranged along the length direction, wherein the tool body comprises a guide part (12) and a drill tip (13), the guide part (12) is connected between the drill neck and the drill tip (13), and the depth-control drilling tool is characterized in that,

the depth control drill (1) further comprises a baffle part (14);

the blocking part (14) is arranged at a preset height position on the drill neck or the cutter body, so that the length of the cutter body between the bottom surface of the blocking part (14) and the end surface of the drill tip (13) is the target drilling depth, and the projection of the blocking part (14) on the back drilling surface of the PCB (2) is not overlapped with the corresponding back drilling hole in the back drilling working state.

2. The depth-control drill bit according to claim 1, wherein the stopper (14) comprises a body (141) and a contact portion (142) provided at the bottom of the body (141);

the contact part (142) is used for being in contact electrical connection with a conductive layer of the back drilling surface of the PCB (2) or in contact with a pressure sensor of the back drilling surface of the PCB (2).

3. The depth-controlling drill bit as claimed in claim 2, wherein the body (141) is sleeved on the periphery of the drill neck or the guide portion (12).

4. The depth-control drill insert as claimed in claim 3, wherein the contact portion (142) is protruded from a bottom surface of the body (141), and a predetermined gap is formed between the contact portion (142) and the guide portion (12).

5. The depth-control drill bit as claimed in claim 4, wherein the contact portion (142) is a hollow structure with a plane contact surface, and is uniformly arranged around the periphery of the guide portion (12).

6. The depth-control drill bit according to claim 1, characterized in that the outer side of the guide part (12) is provided with at least two mounting positions along the length direction thereof, and each mounting position corresponds to different target drilling depths;

the blocking part (14) is detachably arranged at an installation position corresponding to the current target drilling depth.

7. A PCB back drilling depth control method is characterized by comprising the following steps:

providing a PCB (2) with a metalized through hole;

applying the depth-controlling drilling tool (1) according to any one of claims 1 to 6, back-drilling from the back-drilled drilling surface of the PCB (2) at the corresponding position of the metallized through hole;

and controlling the depth control drilling cutter (1) to stop back drilling when the stop part (14) is recognized to descend to be in contact with the back drilling surface of the PCB (2).

8. The PCB back-drilling depth control method according to claim 7, wherein the back-drilling surface of the PCB (2) is provided with a conductive layer; the baffle part (14) comprises a body (141) and a contact part (142) arranged at the bottom of the body (141), and the contact part (142) is used for being in contact and electric connection with a conductive layer of a back drilling surface of the PCB (2);

the method of identifying whether the standoff portion (14) is lowered into contact with the back-drilled surface of the PCB (2) comprises: and detecting the electric conduction state between the contact part (142) and the conductive layer in real time during the drilling process, and judging that the baffle part (14) descends to be in contact with the back drilling surface of the PCB (2) when the electric conduction state is switched from open circuit to short circuit.

9. The PCB back-drilling depth control method according to claim 7, wherein a pressure sensor is arranged at the projection position of the back-drilling surface of the PCB (2) on the barrier part (14); the baffle part (14) comprises a body (141) and a contact part (142) arranged at the bottom of the body (141); the contact part (142) is used for contacting with a pressure sensor of a back drilling surface of the PCB (2);

the method of identifying whether the kicker (14) is down into contact with the backdrilling surface of the PCB (2) comprises: and detecting the pressure value of the pressure sensor in real time, and judging that the barrier part (14) descends to contact with the back drilling surface of the PCB (2) when the pressure value is increased sharply.

10. The PCB back-drilling depth control method according to claim 9, wherein the back-drilling surface of the PCB (2) is further provided with a protective layer.

Images