CN108541139A - A kind of PCB via holes production method and PCB - Google Patents

Abstract

The invention discloses a method for making a PCB via hole, which comprises the following steps: performing a primary drilling with a pre-large aperture at the position of the via hole of the PCB, and performing thick copper plating on the via hole after the primary drilling The primary plated through hole, the secondary drilling is performed on the thick copper-plated via hole, and the secondary plated through hole is performed on the secondary drilled via hole. The embodiment scheme of the present invention provides a method for manufacturing PCB via holes and PCB, which can solve the problem that the flatness of the hole wall of PI, PTFE and other high-frequency plates is poor after drilling, and it is difficult to obtain a uniform thickness coating in the plated through hole process. Improve the reliability and quality of PCB products.

Description

Method for manufacturing PCB via hole and PCB

technical field

The invention relates to the field of electronic manufacturing, in particular to a method for manufacturing a PCB via hole and a PCB.

Background technique

With the high frequency and refinement of electronic products, the proportion of high-frequency circuit boards and high-end circuit boards with special substrates in the PCB (Printed Circuit Board, printed circuit board) industry has increased year by year. High-frequency circuit boards represented by amine) sheets and PTFE (Poly Tetra Fluoroethylene, polytetrafluoroethylene) sheets have been widely used. The flatness of the flatness, especially the flatness of the copper layer on the wall of the via hole also has relatively stringent requirements, and high-frequency sheets such as PI sheets and PTFE sheets usually have good toughness. In the process of drilling such sheets , the drill pin is easy to pull the substrate, resulting in poor flatness of the hole wall after drilling, and the chemical inertia of this high-frequency plate is usually strong, the substrate pulled out of the hole wall is not easy to be bitten and flattened by the liquid medicine. It poses a great challenge to the subsequent plated through hole process. Due to the poor flatness of the hole wall, the plated through hole process cannot obtain a uniform thickness of the plating layer, which brings great damage to the reliability and quality of the circuit board product.

Contents of the invention

The embodiment of the present invention provides a method for manufacturing PCB via holes and PCB, which can solve the problem that the flatness of the hole wall of PI, PTFE and other high-frequency plates is poor after drilling, and the plated through hole process is difficult to obtain a uniform thickness coating, so as to improve PCB. Product reliability and quality.

In the first aspect, a method for manufacturing a PCB via hole provided by an embodiment of the present invention includes:

Carry out a drilling with a pre-large diameter at the position of the via hole of the substrate;

A plated through hole with thick copper plating for the via hole after the first drilling;

Secondary drilling of via holes with thick copper plating;

Secondary plated through holes are performed on via holes after secondary drilling.

In a second aspect, an embodiment of the present invention provides a PCB, and the via hole of the PCB is obtained by the method for manufacturing the via hole in the aforementioned first aspect.

A PCB via hole manufacturing method and PCB provided by the embodiment of the present invention, drill a via hole with an aperture larger than the designed aperture through pre-large primary drilling, and adopt a thick copper-plated through-hole process to drill the pre-large Thick copper is plated on the hole wall of the via hole, and then the via hole plated with thick copper is drilled twice to obtain a flat and smooth hole wall, and then the via hole is plated twice to obtain the thickness The uniform conducting hole conductive copper layer effectively solves the problem of making via holes in high-frequency plates such as PI and PTFE in the prior art, and effectively improves the reliability of such substrate PCBs.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present invention. As far as the skilled person is concerned, other drawings can also be obtained based on these drawings on the premise of not paying creative work.

Fig. 1 is a schematic flowchart of a method for manufacturing a PCB via hole provided by an embodiment of the present invention;

FIG. 2 is a schematic engineering diagram of a method for manufacturing a PCB via hole provided by an embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

It should be understood that when used in this specification and the appended claims, the terms "comprising" and "comprises" indicate the presence of described features, integers, steps, operations, elements and/or components, but do not exclude one or Presence or addition of multiple other features, integers, steps, operations, elements, components and/or collections thereof.

It should also be understood that the terminology used in the description of the present invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the present invention. As used in this specification and the appended claims, the singular forms "a", "an" and "the" are intended to include plural referents unless the context clearly dictates otherwise.

It should also be further understood that the term "and/or" used in the description of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations .

As shown in FIG. 1, an embodiment of the present invention provides a method for manufacturing a PCB via hole, including the following steps:

Step S11, drilling a hole with a pre-large aperture at the position of the via hole of the PCB;

Step S12, performing a primary plated through hole with thick copper plating on the via hole after the primary drilling;

Step S13, performing secondary drilling on the thick copper-plated via hole;

Step S14, performing secondary through-plating on the via hole after secondary drilling;

Through a pre-large drilling hole, a via hole with a diameter larger than the design aperture is drilled, and a through-hole plating process of thick copper plating is used to plate the pre-large via hole wall with thick copper, and then plate it with thick copper. Secondary drilling of the via hole to obtain a smooth and clean hole wall, and then secondary plating of the via hole to obtain a conductive copper layer of the via hole with uniform thickness, which effectively solves the problem in the aforementioned prior art. The problem of making via holes in high-frequency boards such as PI and PTFE effectively improves the reliability of such substrate PCBs.

As an alternative, the primary drilling of aperture pre-enlargement refers to the method of increasing the diameter of the drill needle to drill a conduction hole with an aperture larger than the actual design aperture;

Further, the diameter of the drill is increased by 0.01mm to 0.02mm, and a conduction hole is drilled that is 0.01mm to 0.02mm larger than the actual design aperture. The needle speed is 0.8m/min～0.4m/min, and the needle withdrawal speed is 6m/min～10m/min.

As an optional solution, the primary through-hole plated through hole with thick copper plating on the via hole after drilling includes: performing a patterning process on the PCB after drilling, and the patterning process is used to ensure that the follow-up The thick copper plating process only attaches thick copper to the hole wall and the edge of the via hole, and then performs the thick copper plating process on the PCB after the pattern pasting process.

As an optional solution, the graphic pasting process includes: pasting a dry film on the surface of the PCB after drilling a hole, and opening a dry film window at the position of the via hole. The hole diameter is 0.01mm ~ 0.02mm larger.

As an alternative, the production process of thick copper plating includes: using high current and long-term electroplating parameters for thick copper plating, wherein the current parameters are 25asf~35asf, the electroplating time is 25min~35min, and the thickness of the obtained copper coating is 15um～25um.

As an optional solution, the secondary drilling of via holes after thick copper plating includes: selecting a drill whose diameter matches the actual design aperture of the via hole, and drilling a via hole that is consistent with the actual design aperture of the via hole. Hole, wherein, the drilling speed is 130krpm~150krpm, the needle entry speed is 0.8m/min~0.4m/min, and the needle withdrawal speed is 5m/min~9m/min.

As an optional solution, performing secondary plated through holes on the through holes after secondary drilling includes: performing the secondary plated through holes using a normal fine electroplating process, wherein the current parameters are 16asf-18asf, and the plating time It is 16min～20min.

As shown in FIG. 2 , it is a schematic engineering drawing of a method for manufacturing a PCB via hole provided by an embodiment of the present invention. In this figure, it clearly shows the process of manufacturing a via hole provided by an embodiment of the present invention. 21) When drilling a hole, use a drill with a larger diameter to drill the hole to obtain a through hole with a larger diameter than the actual design aperture. Taking the actual design aperture as d as an example, use a larger drill to drill the hole to obtain d+ 0.01mm ~ 0.02mm through hole, and then conduct a plated through hole process. As mentioned in the background technology above, due to the characteristics of the PCB substrate, the hole wall usually fails to obtain better flatness, and the surface of the hole wall Uneven (not shown in the figure), under such hole wall conditions, a thick copper plating process of one-time plating through holes is used to obtain a thicker copper layer (23) of 15um to 25um. In the process of copper plating, usually Next, it is also necessary to carry out a pattern-attaching process on the PCB, attaching a dry film 22 to the position where copper does not need to be attached to the surface of the PCB, and then performing a secondary drilling process on the PCB after the primary through-hole plating. At this time, the diameter of the drill used is In order to design the diameter of the drill needle required by the aperture, the through hole with the design aperture of d is drilled. After the second drilling is completed, the next step is the process of the second plating through hole. It should be explained that the process of the second plating through hole In the process of micro-etching the copper layer obtained by thick copper plating, it is usually necessary to increase the roughness of the surface of the copper layer, so that it is easier to attach a new copper layer in the process of secondary through-hole plating. In addition, it is also required The dry film 22 added in the preceding process is processed in the leg mold process. After the above two sub-processes are completed, the secondary plated through-hole process can be started. The surface already has good flatness, and the secondary plating through-hole process usually follows the conventional electroplating parameters to obtain a very smooth and smooth conductive copper layer with excellent uniformity of copper layer thickness, which greatly improves the high-frequency and other special substrates. The quality of the through-hole plating of PCB products effectively improves the reliability of the products.

An embodiment of the present invention provides a PCB, and the via hole of the PCB is obtained by the method for manufacturing the via hole described in the foregoing embodiments.

The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person familiar with the technical field can easily think of various equivalents within the technical scope disclosed in the present invention. Modifications or replacements shall all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (9)

1. A method for making a PCB via hole, characterized in that, comprising the following steps: Carrying out a drilling with a pre-large aperture at the position of the via hole of the PCB; A primary plated through hole with thick copper plating is performed on the via hole after the primary drilling; Carrying out secondary drilling to the via hole of the thick copper plating; A secondary plated through hole is performed on the via hole after the secondary drilling. 2. The method for making a via hole according to claim 1, wherein the primary drilling of the pre-large aperture comprises: adopting the method of increasing the diameter of a drill needle to drill a via hole with an aperture larger than the actual design aperture . 3. The method for making a via hole according to claim 2, wherein the diameter of the drill needle is increased by 0.01 mm to 0.02 mm to drill a via hole that is 0.01 mm to 0.02 mm larger than the actual design diameter, and the drill The needle speed is 120krpm~150krpm, the needle entry speed is 0.8m/min~0.4m/min, and the needle withdrawal speed is 6m/min~10m/min. 4. The method for making a via hole according to claim 1, wherein the primary plated through hole for performing thick copper plating on the via hole after the primary drilling comprises: Carrying out a graphic pasting process on the PCB after the primary drilling, the graphic pasting process is used to ensure that the subsequent thick copper plating process only attaches thick copper to the hole wall and the edge of the via hole; A thick copper plating process is performed on the PCB after the graphic pasting process. 5. The method for producing a via hole according to claim 4, characterized in that, the pattern pasting process comprises: pasting a dry film on the surface of the PCB after the primary drilling, and placing a film at the position of the via hole Perform dry film window opening treatment, wherein the diameter of the window opening is 0.01 mm to 0.02 mm larger than the hole diameter after the first drilling. 6. The method for making a via hole according to claim 4, wherein the thick copper plating comprises: using high current and long-time electroplating parameters to perform thick copper plating, wherein the current parameters are 25asf to 35asf, and the electroplating The time is 25 minutes to 35 minutes, and the thickness of the obtained copper plating layer is 15 um to 25 um. 7. The method for making a via hole according to claim 1, wherein the secondary drilling of the via hole with thick copper plating comprises: selecting a drill whose diameter matches the actual design aperture of the via hole , Drill a through hole that is consistent with the actual design aperture of the via hole, wherein the drill speed is 130krpm~150krpm, the needle entry speed is 0.8m/min~0.4m/min, and the needle withdrawal speed is 5m/min~9m/min. 8. The method for making a via hole according to claim 1, wherein performing secondary plating on the via hole after the secondary drilling comprises: performing the secondary plating by using a normal fine electroplating process Through holes, wherein, the current parameter is 16asf-18asf, and the electroplating time is 16min-20min. 9. A PCB, characterized in that at least one via hole on the PCB is made by the via hole manufacturing method according to any one of claims 1-8.