CN111225496B

CN111225496B - Manufacturing process of metal semi-clad structure

Info

Publication number: CN111225496B
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: 2023-03-10
Anticipated expiration: 2040-01-10
Also published as: CN111225496A

Abstract

The invention discloses a metal half-wrapped edge structure, a manufacturing process and a PCB (printed Circuit Board), comprising a plurality of metal half-wrapped copper plated on the side surface of the edge of the 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, the same side edge of the metal semi-clad copper is connected with one side of the PCB, and the length of the metal semi-clad copper in the thickness direction of the PCB is equal to 1/3-2/3 of the thickness of the PCB. 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

Manufacturing process of metal semi-edge-covered structure

Technical Field

The invention belongs to the technical field of PCB manufacturing, and particularly relates to a manufacturing process of a metal half-edge-covered structure.

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 mainly 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 manufacturing process of a metal half-clad edge structure and a PCB (printed circuit board), so as to solve the technical problem.

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 along the thickness direction of the PCB is equal to 1/3 to 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 process, namely milling 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, 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 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 through the metal half-clad copper arranged at intervals, and the anti-interference performance of the PCB is enhanced.

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. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

Please refer to fig. 1.

The embodiment provides a metal half-edge structure, which comprises a plurality of metal half-clad copper 12 plated on the side surface 11 of the PCB10.

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 PCB10. 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 metal half-clad member is partially clad (referred to as a half-clad member in the present embodiment).

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

As an alternative mode, the length of the metal semi-copper-clad 12 in the thickness direction of the PCB10 is equal to 1/3 to 2/3 of the thickness of the PCB10. In the present embodiment, the length of the metal-clad copper 12 in the thickness direction of the PCB10 is equal to 1/2 of the thickness of the PCB10.

The half limit structure of metal that this embodiment provided, on the influence basis of back drilling elimination "Stub" to signal transmission integrality, through half copper clad 12 of metal that the interval set up, can further eliminate the influence of "Stub" to signal integrality, reinforcing PCB 10's interference killing feature.

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 procedure, 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 same position of 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 off the tin layer which does not need to be covered with the metal to expose the copper layer, so that the residual tin layer protects the copper layer which needs to be covered with the 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-covered 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, the edge-covering metal 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.

When the PCB10 is fabricated with the metal half-clad structure, the fabrication is usually performed individually from PCB to PCB. In order to improve the manufacturing accuracy and efficiency, the PCBs need to be stacked.

In the case of depth milling and drilling, the tin needs to be milled away completely, possibly slightly milling or drilling to the copper surface, but without damaging the substrate.

Therefore, the first time stacking of the plurality of PCBs 10 may be performed according to the expansion and contraction coefficient of the PCBs 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 in all PCBs 10 in the 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 value of 10 μm and 20 μm, respectively, and the sum of the designed copper thickness and tin thickness is 35 μm, the difference in the shrinkage value is 10 μm and less than 35 μm, so that the two PCBs 10 may be stacked together, or otherwise 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 secondarily according to the thickness of the PCBs 10. Similar to the first stacking principle, the thickness difference between any two PCBs 10 cannot be greater than a preset value, and stacking is required if the thickness difference is greater than the preset value, otherwise stacking can be performed. 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-plate depth-control milling in any plate edge direction is finished, carrying out whole-plate depth-control milling on the whole PNL plate along other plate edge directions of the single PCS plate.

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, carrying out whole-plate drilling 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 of which corresponds to one PCB10.

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 a 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 an interval, so as to enhance the anti-interference performance of the PCB10.

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 stated 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," 8230, "" 8230 "; joined," "connected to," or "coupled to" another element or layer, it can be directly on, joined to, 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," "8230;" \8230 "", "with," "8230," "directly bonded to," "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., "on 8230; \8230between" and "directly on 8230; \8230between," "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," "underlying," "below," "at 8230;, \8230," "lower," "above," "upper," etc., may be used herein for ease of description to describe the relationship of one element or feature to another element or feature 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" \ 8230; \ 8230 "", may encompass both an orientation of facing up and facing down. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors 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. A manufacturing process of a metal semi-edge-wrapped structure is characterized by comprising the following steps:

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 the tin layer without needing metal edge covering to expose the copper layer, so that the copper layer needing metal edge covering is protected by the residual tin layer, and the shape of the tin surface at each position is rectangular;

and in the etching process, the exposed copper layer is etched, and then the tin layers of other parts are removed to expose the copper layer needing metal edge covering, so that the metal half edge covering is realized.

2. The manufacturing process of claim 1, wherein the depth-controlled milling process comprises:

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

the drilling process comprises the following steps:

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.

3. The manufacturing process according to claim 1, further comprising, before the depth control milling step:

4. The manufacturing process according to claim 3, further comprising, before the depth-control milling process: