Hole site processing method of plated-through hole of PCB (Printed Circuit Board) and PCB

Abstract

The invention belongs to the technical field of electronic structures, and discloses a hole site processing method of a plated-through hole of a PCB and the PCB, and the processing method comprises the steps: obtaining the diameter H of the plated-through hole to be processed, and determining the ring width L of a welding ring according to the diameter H, L > = 16mil; a plurality of notches distributed at intervals are formed in the inner side wall of the welding ring in the axial direction of the welding ring in a penetrating mode. And placing the welding ring with the gap in the hole position of the plated-through hole of the PCB, and then processing the plated-through hole. When the plated-through hole is processed on the PCB in the mode, the problem of local stress concentration on the inner side of the welding ring can be effectively relieved, the welding ring can be stably fixed on the PCB, and the possibility that the welding ring is pulled and falls off is reduced.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of electronic structures, in particular to a hole position processing method of a metallized hole of a PCB (Printed Circuit Board) and the PCB. BACKGROUND

[0002] With the trend of electronic devices developing towards high integration and high performance, the complexity and reliability requirements of PCBs as core electronic component interconnection carriers are significantly improved. Especially in the processing of PCBs with large apertures (such as diameters greater than 0.8 mm), the connection reliability of the inner layer copper foil and the metallized hole (PTH hole) directly affects the signal transmission stability and product life.

[0003] In the prior art, in order to enhance the connection reliability of the inner layer copper foil and the PTH hole, a "pre-set solder ring (PAD ring)" process is adopted, that is, a PAD ring is formed in advance during drilling. The process can theoretically improve the adhesion of the copper ring to the substrate by optimizing the bonding surface structure of the copper ring and the substrate.

[0004] However, during the drilling process, the direct contact between the drill bit and the edge of the PAD ring generates local high temperature (up to more than 300 DEG C) and impact stress, causing plastic deformation or even tearing of the material at the edge of the PAD ring; at the same time, the difference in thermal expansion coefficient between the copper ring and the substrate (the thermal expansion coefficient of copper is 17x10⁻ 6 / ℃, and the thermal expansion coefficient of FR-4 is 14x10⁻ 6 / ℃) will further intensify the stress concentration, causing the PAD to be easily pulled off. SUMMARY

[0005] The purpose of the application is to provide a hole position processing method of a metallized hole of a PCB and a PCB, which solves the problem that in the prior art, the PAD ring is easily pulled off during the processing of the PTH hole of the PCB.

[0006] To achieve this purpose, the application adopts the following technical solutions:

[0007] In a first aspect, the application provides a hole position processing method of a metallized hole of a PCB, which comprises:

[0008] obtaining the diameter H of the metallized hole to be processed, determining the ring width L of the solder ring according to the diameter H, L≥16 mil;

[0009] a plurality of spaced-apart notches are formed in the inner side wall of the solder ring along the axial direction of the solder ring;

[0010] placing the solder ring with the notches in the hole position of the metallized hole of the PCB and then processing the metallized hole.

[0011] Optionally, the provision of multiple spaced notches penetrating the inner wall of the weld ring along its axis specifically includes:

[0012] Obtain a solid pad and machine through holes in the solid pad to form the solder ring;

[0013] Multiple through-holes are machined along the axial direction on the inner side of the welding ring so that the inner side of the welding ring is an internal gear.

[0014] Optionally, the pitch m of the internal gear is determined based on the diameter H.

[0015] Optionally, when the diameter H < 4.0 mm, the tooth pitch m = 6 mil;

[0016] When 4.0mm≤H≤5.5mm, the tooth pitch m=8mil;

[0017] When the diameter H > 5.5 mm, the tooth pitch m = 10 mil.

[0018] Optionally, obtaining the diameter H of the metallized hole to be processed, and determining the ring width L of the weld ring based on the diameter H, specifically includes:

[0019] When 3.0mm≤H≤3.95mm, the ring width L≥16mil;

[0020] When 4.0mm≤H≤4.95mm, the ring width L≥18mil;

[0021] When 5.0mm≤H, the ring width L≥20mil.

[0022] Optionally, before machining the metallized hole, the method further includes:

[0023] Multiple stress relief positions are arranged at intervals within the welding ring, and at least one stress relief hole is machined at each stress relief position.

[0024] Optionally, the plurality of stress-relief locations are distributed at equal angular intervals along the circumference of the metallized hole.

[0025] Optionally, the diameter of the stress relief hole... .

[0026] Optionally, the offset between the machining center of the stress relief hole and the machining center of the metallized hole is L. .

[0027] Secondly, this application provides a PCB board in which metallized holes are processed using the hole-position processing method for metallized holes of the PCB board as described in any one of the first aspects, including:

[0028] The substrate has metallized holes, and a solder ring is disposed in the metallized holes. The inner side of the solder ring is provided with a plurality of axially penetrating notches.

[0029] The beneficial effects of this invention are:

[0030] The ring width L of the solder ring is determined based on the diameter H of the PTH (Position Tolerancing Hole). After accurately designing the solder ring, metallized holes are machined on the PCB board using the solder ring as a reference. During the machining process, multiple notches are opened at intervals on the inner side of the solder ring, significantly reducing the contact area between the inner side of the solder ring and the drill bit. This effectively reduces the tensile force on the solder ring, and the locally generated high temperature can also be transferred outward through the notches, ensuring that the local temperature of the solder ring remains within a suitable range. Therefore, when machining metallized holes on the PCB board in this way, the problem of local stress concentration on the inner side of the solder ring can be effectively alleviated, ensuring that the solder ring can be stably fixed on the PCB board and reducing the possibility of the solder ring being pulled off. Attached Figure Description

[0031] Figure 1 This is a flowchart illustrating the hole location processing method for metallized holes on a PCB board in an embodiment of the present invention.

[0032] Figure 2 This is a front view of the solder ring in the PCB board in an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of the welding ring processing flow of the PCB board metallized hole hole processing method in an embodiment of the present invention.

[0034] Figure 4 This is a schematic diagram illustrating the design of the inner tooth pitch of the solder ring in the hole position processing method of the metallized hole of the PCB board in an embodiment of the present invention.

[0035] In the picture:

[0036] 1. Weld ring; 11. Notch; 2. Pressure relief hole. Detailed Implementation

[0037] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0038] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0039] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0040] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0041] This application discloses a method for machining the metallized holes of a PCB board and the PCB board itself.

[0042] Reference Figure 1 and Figure 2 The hole location processing method for the metallized holes on this PCB board includes:

[0043] Step S1: Obtain the diameter H of the metallized hole to be processed, and determine the ring width L of the welding ring 1 based on the diameter H, where L≥16mil.

[0044] Plated Through Hole (PTH) refers to the formation of conductive metal within the hole of a PCB board to achieve electrical interconnection between multilayer boards. Before PTH processing, a solder ring 1 is fixed at the hole location on the PCB board to provide precise positioning for subsequent drilling and ensure minimal hole position deviation. The hole diameter H of the PTH can be determined according to the production requirements of the PCB board, and the required solder ring 1 width L is determined based on H. The corresponding solder ring 1 can then be produced based on the ring width L. The ring width of solder ring 1 refers to the width of the copper foil surrounding the through hole. Its core functions include conductive connection, mechanical support, and electroplating base. If the ring width is too small, it will lead to a current density base, causing an "edge effect," and it will also be more susceptible to being pulled off. Therefore, the ring width L is set to ≥ 16mil.

[0045] Step S2: Along the axial direction of the welding ring 1, multiple spaced notches 11 are made through the inner wall of the welding ring 1.

[0046] By creating a notch 11 on the inner side of the welding ring 1, the area of ​​the inner side of the welding ring 1 can be reduced, while ensuring that the overall strength of the welding ring 1 meets the requirements. During the drilling process, the contact area between the inner side of the welding ring 1 and the drill bit can be reduced, thereby reducing the tensile force on the inner side of the welding ring 1.

[0047] Step S3: Place the solder ring 1 with notch 11 into the hole position of the metallized hole on the PCB board and then process the metallized hole.

[0048] The designed solder ring 1 is fixed at the hole on the PCB board. Using the inner diameter of the solder ring 1 as a reference, the drill bit is inserted into the solder ring 1 and aligned with the center of the hole using a vision positioning system or a laser alignment system, and then drilling is performed. The specific drilling process can be referred to the existing technology, and will not be elaborated here.

[0049] Through steps S1 to S3, the ring width L of the solder ring 1 is determined based on the diameter H of the PTH. After accurately designing the solder ring 1, metallized holes are machined on the PCB board using the solder ring 1 as a reference. During machining, multiple notches 11 are spaced apart on the inner side of the solder ring 1, significantly reducing the contact area between the inner side of the solder ring 1 and the drill bit. This effectively reduces the tensile force on the solder ring 1, and the locally generated high temperature can be transferred outward through the notches 11, ensuring that the local temperature of the solder ring 1 remains within a suitable range. Therefore, this method effectively alleviates the problem of local stress concentration on the inner side of the solder ring 1 when machining metallized holes on the PCB board, ensuring that the solder ring 1 can be stably fixed on the PCB board and reducing the possibility of the solder ring 1 being pulled off.

[0050] Reference Figure 3 Optionally, step S2 above specifically includes:

[0051] Step S21: Obtain a solid pad and machine through holes in the solid pad to form a solder ring 1.

[0052] The maximum outer diameter of the required weld ring 1 can be determined based on the diameter H of the PTH. A suitable solid pad can then be selected as the material for the weld ring 1. A through hole is machined within the solid pad according to the determined ring width L to form the weld ring 1. A circular pad is preferred to distribute stress during machining and reduce the risk of cracking. The outer diameter of the solid pad = ring width × 2 + hole diameter.

[0053] Step S22: Multiple through notches 11 are machined along the axial direction on the inner side of the welding ring 1 so that the inner side of the welding ring 1 is an internal gear.

[0054] After the welding ring 1 is processed, multiple notches 11 are made through the inner wall of the welding ring 1, and the multiple notches 11 are distributed at equal angles along the circumference of the welding ring 1, so that an internal gear is formed on the inner side of the welding ring 1. This reduces the contact area and improves the heat dissipation effect, reducing the possibility of excessive local temperature.

[0055] Reference Figure 4 Optionally, the pitch m of the internal gear can be determined based on the diameter H.

[0056] Specifically, when the diameter H < 4.0 mm, the tooth pitch m = 6 mil; when 4.0 mm ≤ H ≤ 5.5 mm, the tooth pitch m = 8 mil; and when the diameter H > 5.5 mm, the tooth pitch m = 10 mil.

[0057] The tooth pitch not only determines the area of ​​the inner side of the weld ring 1 that can contact the drill bit, but also affects the space between two adjacent teeth, thus affecting the heat dissipation effect. When the diameter H of the PTH being machined is small, the tooth pitch m can also be set smaller to further improve the strength of the weld ring 1 itself. When the diameter of the PTH being machined is large, the corresponding ring width and the size of the weld ring 1 are also increased, and the tooth pitch is also increased accordingly. Under the premise that the strength of the weld ring 1 itself meets the requirements, the area that can contact the drill bit can be reduced and the heat dissipation effect can be improved.

[0058] Optionally, step S1 above specifically includes: when 3.0mm≤H≤3.95mm, the ring width L≥16mil; when 4.0mm≤H≤4.95mm, the ring width L≥18mil; when 5.0mm≤H, the ring width L≥20mil.

[0059] The ring block of welding ring 1 is related to the diameter H of PTH. When the diameter of PTH is large, welding ring 1 with a larger ring width should be selected to meet the overall thermal shock and vibration resistance performance. When the diameter H is small, welding ring 1 with a smaller ring width can be selected to save space.

[0060] Optionally, before machining the metallized holes, multiple stress relief positions are arranged at intervals within the weld ring, and at least one stress relief hole 2 is machined at each stress relief position.

[0061] Specifically, pre-machining stress relief holes 2 at the hole positions can eliminate stress concentration for subsequent through-hole machining, ensuring the quality of through-hole machining. When machining PTH, multiple stress relief positions can be arranged at the hole positions. These multiple stress relief positions can be distributed at equal angles around the circumference of PTH or at non-equal angles. In this embodiment, the multiple stress relief positions are distributed at equal angle intervals along the circumference of the metallized hole.

[0062] One unloading hole 2 can be machined at each unloading position, or multiple unloading holes 2 can be machined sequentially. In this embodiment, only one unloading hole 2 is machined at each unloading position.

[0063] Optionally, the diameter of the unloading hole 2 The offset between the machining center of the stress relief hole 2 and the machining center of the metallized hole is L. .

[0064] The size of the stress relief hole 2 can be calculated based on the diameter H of the PTH, and the distance between the center of the stress relief hole 2 and the PTH is the offset mentioned above. This offset can also be calculated based on the diameter H of the PTH. By using this offset, the machining position of the stress relief hole 2 can be determined more accurately, so that the corresponding stress relief hole 2 can be machined accurately, and the PTH can be machined with higher quality.

[0065] The PCB board is processed with metallized holes using the hole processing method for metallized holes in the above embodiment. The PCB board includes a substrate. The substrate has metallized holes, and a solder ring 1 is disposed in the metallized hole. The inner side of the solder ring 1 is provided with a plurality of axially penetrating notches 11.

[0066] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for machining the hole positions of metallized holes on a PCB board, characterized in that, include: Obtain the diameter H of the metallized hole to be processed, and determine the ring width L of the welding ring based on the diameter H, where L≥16mil; Along the axial direction of the welding ring, a plurality of spaced notches are made through the inner sidewall of the welding ring; The solder ring with the notch is placed in the hole of the metallized hole on the PCB board and then the metallized hole is machined.

2. The method for machining the metallized holes of a PCB board according to claim 1, characterized in that, The provision of multiple spaced notches penetrating the inner wall of the weld ring along its axis specifically includes: Obtain a solid pad and machine through holes in the solid pad to form the solder ring; Multiple through-holes are machined along the axial direction on the inner side of the welding ring so that the inner side of the welding ring is an internal gear.

3. The method for machining the metallized holes of a PCB board according to claim 2, characterized in that, The pitch m of the internal gear is determined based on the diameter H.

4. The method for machining the metallized holes of a PCB board according to claim 3, characterized in that, When the diameter H < 4.0 mm, the tooth pitch m = 6 mil; When 4.0mm≤H≤5.5mm, the tooth pitch m=8mil; When the diameter H > 5.5 mm, the tooth pitch m = 10 mil.

5. The method for machining the metallized holes of a PCB board according to claim 1, characterized in that, The process of obtaining the diameter H of the metallized hole to be processed and determining the ring width L of the weld ring based on the diameter H specifically includes: When 3.0mm≤H≤3.95mm, the ring width L≥16mil; When 4.0mm≤H≤4.95mm, the ring width L≥18mil; When 5.0mm≤H, the ring width L≥20mil.

6. The method for machining the metallized holes of a PCB board according to claim 1, characterized in that, Before machining the metallized hole, the process further includes: Multiple stress relief positions are arranged at intervals within the welding ring, and at least one stress relief hole is machined at each stress relief position.

7. The method for machining the metallized holes of a PCB board according to claim 6, characterized in that, The multiple stress-relief locations are distributed at equal angular intervals along the circumference of the metallized holes.

8. The method for machining the metallized holes of a PCB board according to claim 6, characterized in that, The diameter of the stress relief hole .

9. The method for machining the metallized holes of a PCB board according to claim 8, characterized in that, The offset between the machining center of the stress relief hole and the machining center of the metallized hole is L. .

10. A PCB board, characterized in that, The metallization hole is processed by the hole-position processing method for metallized holes of a PCB board as described in any one of claims 1 to 9, including: The substrate has metallized holes, and a solder ring is disposed in the metallized holes. The inner side of the solder ring is provided with a plurality of axially penetrating notches.

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