CN111225496A

CN111225496A - Metal half-clad structure, manufacturing process and PCB

Info

Publication number: CN111225496A
Application number: CN202010027338.1A
Authority: CN
Inventors: 孟昭光; 赵南清; 曾国权
Original assignee: Dongguan Wuzhu Technology Co ltd
Current assignee: Dongguan Wuzhu Technology Co ltd
Priority date: 2020-01-10
Filing date: 2020-01-10
Publication date: 2020-06-02
Anticipated expiration: 2040-01-10
Also published as: CN111225496B

Abstract

The invention discloses a metal semi-clad edge structure, a manufacturing process and a PCB (printed Circuit Board), comprising a plurality of metal semi-clad copper plated on the side surface of the edge of the PCB; it is a plurality of half copper-clad of metal is followed the interval of plate edge side sets up, half copper-clad of metal shape is the rectangle, and is a plurality of half copper-clad of metal with one side with the one side of PCB is connected, half copper-clad of metal is followed length of PCB's thickness direction equals 1/3 ~ 2/3 of PCB's thickness. According to the metal half-clad edge structure, the manufacturing process and the PCB provided by the embodiment of the invention, the influence of Stub on the signal integrity can be further eliminated and the anti-interference performance of the PCB is enhanced through the metal half-clad copper arranged at intervals.

Description

Metal half-clad structure, manufacturing process and PCB

Technical Field

The invention belongs to the technical field of PCB (printed circuit board) manufacturing, and particularly relates to a metal half-wrapped edge structure, a manufacturing process and a PCB.

Background

Stub branches are easily generated at the via holes of the PCB, which causes problems of signal interference, reflection, ringing and the like, and causes the integrity of the transmission signal to be poor.

The prior art has primarily eliminated the effect of "Stub" on signal integrity by designing the vias as back drilled holes.

However, the effect of "Stub" on signal integrity is not sufficiently completely eliminated by back-drilling alone, and a new structure is needed to further attenuate the effect of "Stub" on signal integrity.

Disclosure of Invention

The invention aims to provide a metal half-clad structure, a manufacturing process and a PCB (printed circuit board) so as to solve the technical problems.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a metal half-clad structure, including a plurality of metal half-clad copper plated on side surfaces of board edges of a PCB;

the metal semi-clad copper is arranged along the side face of the plate edge at intervals, the metal semi-clad copper is rectangular, and the metal semi-clad copper is connected with one side of the PCB at the same side edge.

Optionally, the length of the metal semi-copper clad in the thickness direction of the PCB is equal to 1/3-2/3 of the thickness of the PCB.

Optionally, the metal half-clad copper is square in shape.

Optionally, the width of the metal half-clad copper is equal to 1/2 of the thickness of the PCB.

Optionally, a plurality of the metal semi-clad copper plates are arranged at equal intervals along the side surface of the plate edge.

In a second aspect, the present invention further provides a manufacturing process of a metal half-clad structure, including:

an electroplating procedure, namely sequentially plating copper and tin on the side surface of the edge of the PCB;

a depth control milling procedure, namely milling off tin at the upper part or the lower part of the side surface of the plate edge;

drilling, namely drilling off the tin layer which does not need to be subjected to metal edge covering, exposing the copper layer, protecting the copper layer which needs to be subjected to metal edge covering by the residual tin layer, and enabling the tin surface at each position to be rectangular;

and etching the exposed copper layer, and removing the tin layer at the rest parts to expose the copper layer needing the metal wrapping so as to realize the metal semi-wrapping.

Optionally, the depth-control milling process includes:

carrying out whole-plate depth-control milling on the whole PNL plate along any plate edge direction of the single PCS plate;

after the whole board depth control milling in any board edge direction is finished, the whole board depth control milling is carried out on the whole PNL board along the other board edge directions of the single PCS board;

the drilling process comprises the following steps:

drilling a whole PNL plate along the direction of any plate edge of the single PCS plate;

after the whole-plate drilling in any plate edge direction is finished, the whole-plate drilling is carried out on the whole PNL plate along the other plate edge directions of the single PCS plate;

wherein the entire PNL board includes a plurality of the single PCS boards.

Optionally, before the depth control milling process, the method further includes:

and a first stacking step of stacking the PCBs once according to the expansion and contraction coefficients of the PCBs.

and a second stacking step of performing secondary stacking on the plurality of PCBs according to the thickness of the PCBs.

In a third aspect, the invention further provides a PCB, wherein the metal half-clad structure is arranged on the side surface of the board edge of the PCB.

Compared with the prior art, the embodiment of the invention has the following beneficial effects:

according to the metal half-clad edge structure, the manufacturing process and the PCB provided by the embodiment of the invention, the influence of Stub on the signal integrity can be further eliminated and the anti-interference performance of the PCB is enhanced through the metal half-clad copper arranged at intervals.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

The structures, ratios, sizes, and the like shown in the present specification are only used for matching with the contents disclosed in the specification, so that those skilled in the art can understand and read the present invention, and do not limit the conditions for implementing the present invention, so that the present invention has no technical significance, and any structural modifications, changes in the ratio relationship, or adjustments of the sizes, without affecting the functions and purposes of the present invention, should still fall within the scope covered by the contents disclosed in the present invention.

Fig. 1 is a schematic structural diagram of a metal half-clad structure according to an embodiment of the present invention;

fig. 2 is a flowchart of a manufacturing process of a metal half-clad structure according to an embodiment of the present invention.

Detailed Description

In order to make the objects, 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, and it is apparent that the embodiments described below are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Please refer to fig. 1.

The present embodiment provides a metal half-clad structure comprising a plurality of metal half-clad copper 12 plated on board edge sides 11 of a PCB 10.

A plurality of metal half-clad copper 12 are provided at equal intervals along the plate edge side 11.

The same side of the plurality of metal half-clad copper 12 is connected to one side of the PCB 10. In this embodiment, the upper sides of the plurality of metal half-clad copper 12 are connected to the top surface of the PCB10, as shown in fig. 1.

The length of the metal half-clad member 12 in the thickness direction of the PCB10 is smaller than the thickness of the PCB10, but the specific ratio between the two is not limited, that is, it is sufficient if the member is partially clad (referred to as a half-clad in the present embodiment).

Specifically, the shape of the metal copper half-clad 12 is rectangular, and in this embodiment, the shape of the metal copper half-clad 12 is square.

As an alternative, the length of the metal-copper half-clad 12 in the thickness direction of the PCB10 is equal to 1/3-2/3 of the thickness of the PCB 10. In this embodiment, the length of the metal-copper half-clad 12 in the thickness direction of the PCB10 is equal to 1/2 the thickness of the PCB 10.

The metal half-clad structure provided by the embodiment can further eliminate the influence of the Stub on the signal integrity and enhance the anti-interference performance of the PCB10 through the metal half-clad copper 12 arranged at intervals on the basis of eliminating the influence of the Stub on the signal transmission integrity by the back drilling hole.

As shown in fig. 2, in another embodiment of the present application, a manufacturing process of a metal half-clad structure is further provided, which can be used for manufacturing the metal half-clad structure, and the manufacturing process includes:

s11, an electroplating process, namely sequentially plating copper and tin on the side surface 11 of the board edge of the PCB 10;

s12, a depth-controlled milling process, namely milling off tin at the upper part or the lower part of the plate edge side surface 11, wherein as shown in figure 1, the position below the metal semi-clad copper 12 is the lower part of the plate edge side surface 11, and the position equal to the metal semi-clad copper 12 is the upper part of the plate edge side surface 11; the procedure is to mill away tin at the position where copper is not needed so as to etch away the copper at the position;

s13, drilling, namely drilling the tin layer which does not need to be wrapped with metal to expose the copper layer, so that the residual tin layer protects the copper layer which needs to be wrapped with metal, the residual tin layer is arranged at intervals, and the shape of the tin layer at each position is rectangular (namely the shape of the metal half-wrapped copper 12 in the drawing); the procedure is to mill away tin at the position where copper is not needed so as to etch away the copper at the position; in addition, the tin is drilled by adopting a drilling mode, so that the metal of the edge is not easy to pull, and the processing quality is improved;

and S14, etching the exposed copper layer, and removing the tin layer at the rest part to expose the copper layer needing the metal wrapping so as to realize the metal half wrapping and obtain the metal half wrapping structure shown in figure 1.

The manufacturing process of the metal semi-edge covering structure provided by the embodiment adopts a drilling process when tin at a place where copper is not needed is removed, the edge covering metal is not easy to pull off, the processing quality is higher, and the anti-interference effect is stronger.

The metal half-clad structure is typically fabricated individually from PCB to PCB when the PCB10 is fabricated. In order to improve the manufacturing accuracy and efficiency, the PCBs need to be stacked.

In the controlled depth milling and drilling process, the tin needs to be milled off completely, and can be milled or drilled slightly to the copper surface, but not to damage the substrate.

Accordingly, the plurality of PCBs 10 may be first stacked according to the expansion and contraction coefficient of the PCB 10. The stacking procedure is positioned before the depth control milling procedure. Specifically, the difference in the expansion and contraction values between any two PCBs 10 of all PCBs 10 in the sub-stack cannot be greater than the sum of the copper thickness and the tin thickness. For example, if the two PCBs 10 have a shrinkage of 10 μm and 20 μm, respectively, and the sum of the designed copper and tin thicknesses is 35 μm, then the shrinkage difference is 10 μm and less than 35 μm, so the two PCBs 10 may be stacked together, otherwise they need to be stacked in different groups.

Further, before the depth control milling process, the method further comprises:

and a second stacking process of stacking the plurality of PCBs 10 twice according to the thickness of the PCB 10. Similar to the first stacking principle described above, the thickness difference between any two PCBs 10 cannot be greater than a preset value, which requires stacking, otherwise they can be stacked together. The preset value can be obtained according to the depth control tolerance.

In another embodiment of the present application, the depth-control milling process includes:

carrying out whole-plate depth control milling on a whole PNL (panel or block) plate along any plate edge direction of the single PCS plate;

and after the whole board depth control milling in any board edge direction is finished, the whole board depth control milling is carried out on the whole PNL board along other board edge directions of the single PCS board.

Specifically, the whole PNL board is subjected to depth control milling along the four board edge directions of the single PCS board, that is, the depth control milling in the board edge direction is performed only one at a time, and after the depth control milling of all the single PCS boards along the board edge direction is completed, the depth control milling in the next board edge direction is performed.

The drilling process comprises the following steps:

drilling holes in the whole PNL plate along the edge direction of any plate of the single PCS plate;

and after the whole-plate drilling in any plate edge direction is finished, the whole-plate drilling is carried out on the whole PNL plate along the other plate edge directions of the single PCS plate.

Specifically, the entire PNL board is drilled along the four board edge directions of the single PCS board, that is, only one board edge direction is drilled at a time, and after drilling of all the single PCS boards along the board edge direction is completed, the next board edge direction is drilled.

Wherein the entire PNL board includes a plurality of single PCS boards, each corresponding to one PCB 10.

According to the manufacturing process of the metal half-clad edge structure, when depth-controlled milling or drilling is carried out, only one plate edge direction is carried out at each time, and machining (depth-controlled milling or drilling) precision is affected only by errors (such as expansion and contraction errors, copper thickness errors, tin thickness errors and the like) in one plate edge direction.

In another embodiment of the present application, a PCB10 is further provided, where the board edge side 11 of the PCB10 is provided with a metal half-clad structure as described above, and the influence of "Stub" on signal integrity can be further eliminated by the metal half-clad copper 12 arranged at intervals, so as to enhance the anti-interference performance of the PCB 10.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "including," and "having" are intended to be inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed and illustrated, unless explicitly indicated as an order of performance. It should also be understood that additional or alternative steps may be employed.

When an element or layer is referred to as being "on" … … "," engaged with "… …", "connected to" or "coupled to" another element or layer, it can be directly on, engaged with, connected to or coupled to the other element or layer, or intervening elements or layers may also be present. In contrast, when an element or layer is referred to as being "directly on … …," "directly engaged with … …," "directly connected to" or "directly coupled to" another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship of elements should be interpreted in a similar manner (e.g., "between … …" and "directly between … …", "adjacent" and "directly adjacent", etc.). As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region or section from another element, component, region or section. Unless clearly indicated by the context, use of terms such as the terms "first," "second," and other numerical values herein does not imply a sequence or order. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

Spatially relative terms, such as "inner," "outer," "below," "… …," "lower," "above," "upper," and the like, may be used herein for ease of description to describe a relationship between one element or feature and one or more other elements or features as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below … …" can encompass both an orientation of facing upward and downward. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. The metal half-clad structure is characterized by comprising a plurality of metal half-clad copper plated on the side surface of the edge of a PCB;

2. The metal half-bordure structure of claim 1, wherein a length of the metal half-bordure in a thickness direction of the PCB is equal to 1/3-2/3 of a thickness of the PCB.

3. The metal half-clad structure as recited in claim 1, wherein the metal half-clad copper is square in shape.

4. The metal half-bordure structure of claim 3, wherein the metal half-clad copper has a width equal to 1/2 of the thickness of the PCB.

5. The metal half-clad structure as defined in claim 1, wherein a plurality of said metal half-clad copper is disposed at equal intervals along the plate edge side.

6. A manufacturing process of a metal semi-edge-wrapped structure is characterized by comprising the following steps:

7. The manufacturing process of claim 6, wherein the depth-controlled milling process comprises:

the drilling process comprises the following steps:

wherein the entire PNL board includes a plurality of the single PCS boards.

8. The manufacturing process according to claim 6, further comprising, before the depth-control milling process:

9. The manufacturing process according to claim 8, further comprising, before the depth-control milling process:

10. A PCB characterized in that the board edge sides of the PCB are provided with a metal half-clad structure as claimed in any one of claims 1 to 5.