CN116916531A - Manufacturing method for improving aperture precision of FPC and FPC - Google Patents

Abstract

The application relates to the technical field of printed circuit boards, and discloses a manufacturing method for improving aperture accuracy of an FPC and the FPC, which comprises the following steps: providing a substrate, wherein the substrate comprises a dielectric layer, and a first metal layer and a second metal layer which are respectively stacked on two opposite sides of the dielectric layer; processing blind holes on the substrate, wherein the blind holes penetrate through the first metal layer and the dielectric layer and do not penetrate through the second metal layer, and the inner aperture of the blind holes is D1; electroplating the substrate to enable a third metal layer to be attached to the inside of the blind hole, and filling the blind hole by the third metal layer; and processing a via hole on the substrate, wherein the via hole penetrates through the third metal layer and acquires the second metal layer, the via hole and the blind hole are coaxially arranged, and the inner aperture of the via hole is D2, and D2 is less than D1. The manufacturing method for improving the aperture precision of the FPC and the FPC can solve the problem that the aperture precision of a plated hole is difficult to control in the traditional FPC manufacturing method.

Description

Manufacturing method for improving aperture precision of FPC and FPC

Technical Field

The application relates to the technical field of printed circuit boards, in particular to a manufacturing method for improving aperture accuracy of an FPC and the FPC.

Background

In order to lay down the tin-passing procedure in the hole of the FPC during the component punching, the hole diameter of the hole in the welding disc area needs to be controlled after copper plating.

The production process of FPC is generally laser drilling (via hole), plasma, shadow and copper plating, i.e. via holes are drilled on the substrate first, and then via copper is plated in the via holes. In the copper plating process, the uniformity of copper plating, the concentration of liquid medicine and the copper plating deep plating capacity of the FPC board surface can all influence the thickness of the hole copper plated in the hole.

In the traditional FPC manufacturing method, the problem that the inner hole diameter precision of the hole after copper plating is difficult to control exists. Wherein, too thin hole copper can cause poor in-hole conduction effect, and there is a risk of interlayer conduction failure; too thick hole copper can lead to the hole in hole after copper plating to be too little, causes the influence to follow-up components and parts, can lead to even product components and parts rosin joint, cohesion not good when serious, causes the functional problem, and then leads to FPC product to scrap.

Disclosure of Invention

The application provides a manufacturing method for improving the aperture precision of an FPC and the FPC, which can solve the problem that the aperture precision of a plated hole is difficult to control in the traditional manufacturing method of the FPC.

In a first aspect, an embodiment of the present application provides a manufacturing method for improving the aperture accuracy of an FPC, including:

providing a substrate, wherein the substrate comprises a dielectric layer, and a first metal layer and a second metal layer which are respectively stacked on two opposite sides of the dielectric layer;

processing a blind hole on the substrate, wherein the blind hole penetrates through the first metal layer and the dielectric layer and does not penetrate through the second metal layer, and the inner aperture of the blind hole is D1;

electroplating the substrate to enable a third metal layer to be attached in the blind hole, and filling the blind hole by the third metal layer;

and processing a via hole on the substrate, wherein the via hole penetrates through the third metal layer and the second metal layer, the via hole and the blind hole are coaxially arranged, and the inner aperture of the via hole is D2, and D2 is less than D1.

In some embodiments, before a via hole is processed on the substrate, first obtaining expansion and contraction data of the substrate, and then adjusting drilling data according to the expansion and contraction data; and when the through hole is processed on the substrate, using the adjusted drilling data.

In some embodiments, when a blind hole is machined in the substrate, a plurality of positioning through holes are machined in the substrate, and the positioning through holes penetrate through the first metal layer, the dielectric layer and the second metal layer; when the substrate is electroplated, a fourth metal layer is attached to the inner hole wall of the positioning through hole; and when the through holes are processed on the substrate, the blind holes and all the positioning through holes are used as alignment reference points.

In some embodiments, at least four positioning through holes are arranged, and four positioning through holes are distributed in a rectangular shape.

In some of these embodiments, the third metal layer has a dishing of less than 5 μm relative to a side of the first metal layer facing away from the dielectric layer.

In some embodiments, after processing a blind hole on the substrate and before electroplating the substrate, attaching a conductive layer on the hole wall of the blind hole and the hole bottom of the blind hole; when the substrate is electroplated, the third metal layer is attached to the conductive layer.

In some of these embodiments, after the conductive layer is attached to both the walls of the blind holes and the bottoms of the blind holes, the conductive layer attached to the bottoms of the blind holes is removed; when the substrate is electroplated, the third metal layer is attached to the conductive layer and the second metal layer.

In some of these embodiments, a fifth metal layer is attached to the first metal layer and a sixth metal layer is attached to the second metal layer when the substrate is electroplated; and when a via hole is processed on the substrate, the via hole penetrates through the fifth metal layer and the sixth metal layer.

In a second aspect, an embodiment of the present application provides a manufacturing method for improving the aperture accuracy of an FPC, including:

providing a substrate, wherein the substrate comprises a dielectric layer, and a first metal layer and a second metal layer which are respectively stacked on two opposite sides of the dielectric layer;

processing a process hole on the substrate, wherein the process hole penetrates through the first metal layer, the dielectric layer and the second metal layer, and the inner aperture of the process hole is D1;

electroplating the substrate to enable a third metal layer to be attached in the process hole, wherein the process is filled by the third metal layer;

and processing a via hole on the substrate, wherein the via hole penetrates through the third metal layer, the via hole and the blind hole are coaxially arranged, and the inner aperture of the via hole is D2, and D2 is less than D1.

In a third aspect, an embodiment of the present application provides an FPC, where the FPC is processed by the manufacturing method for improving the aperture accuracy of the FPC according to the first aspect or the second aspect.

The manufacturing method for improving the aperture precision of the FPC provided by the embodiment of the application has the beneficial effects that: the blind holes penetrating the first metal layer and the dielectric layer and not penetrating the second metal layer are processed on the substrate, then the substrate is electroplated, so that the third metal layer is attached to the blind holes, the blind holes are filled with the third metal layer, finally, through holes penetrating the third metal layer and the second metal layer are processed on the substrate, the through holes and the blind holes are coaxially arranged, the inner aperture of the through holes is D2, D2 is less than D1, the first metal layer and the second metal layer can be electrically conducted by directly using the third metal layer remained after the through holes are processed, the first metal layer and the second metal layer do not need to be electrically conducted by plating hole copper in the holes, the inner aperture accuracy of the through holes is easy to control, and the problem that the inner aperture accuracy of the plated holes is difficult to control due to the traditional mode of electrically conducting the first metal layer and the second metal layer by plating hole copper in the holes is solved.

Compared with the prior art, the FPC provided by the application has similar beneficial effects to those of the prior art, and the manufacturing method for improving the aperture precision of the FPC provided by the application is not repeated here.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a flow chart of a method of manufacturing to improve FPC aperture accuracy in one embodiment of the application;

FIG. 2 (a) is a schematic cross-sectional view of a substrate after processing blind holes according to one embodiment of the present application;

fig. 2 (b) is a schematic cross-sectional view of the substrate after electroplating the substrate shown in fig. 2 (a);

fig. 2 (c) is a schematic cross-sectional view of the substrate shown in fig. 2 (b) after the substrate has been processed with via holes;

FIG. 3 (a) is a schematic cross-sectional view of a substrate after processing positioning holes according to one embodiment of the present application;

fig. 3 (b) is a schematic cross-sectional view of the substrate after electroplating the substrate shown in fig. 3 (a);

fig. 4 is a top view of a substrate after processing alignment vias in one embodiment of the present application.

The meaning of the labels in the figures is:

10. a substrate; 11. a dielectric layer; 12. a first metal layer; 13. a second metal layer;

20. a blind hole;

30. a third metal layer;

40. a via hole;

50. positioning the through hole;

60. a fourth metal layer;

70. a fifth metal layer;

80. and a sixth metal layer.

Detailed Description

The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

Reference in the specification to "one embodiment," "some embodiments," or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," and the like in the specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments" unless expressly specified otherwise. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

In order to describe the technical scheme of the application, the following description is made with reference to specific drawings and embodiments.

Referring to fig. 1 and fig. 2 (a), in a first aspect, an embodiment of the present application provides a manufacturing method for improving the aperture precision of an FPC, including:

s100: a substrate 10 is provided, the substrate 10 comprising a dielectric layer 11 and a first metal layer 12 and a second metal layer 13 respectively stacked on opposite sides of the dielectric layer 11.

Specifically, the material of the dielectric layer 11 may be PI (Polyimide), polyester, polyvinylbenzene, or the like, and the material of the first metal layer 12 and the second metal layer 13 may be copper.

S200: a blind hole 20 is processed on the substrate 10, the blind hole 20 penetrates through the first metal layer 12 and the dielectric layer 11 and does not penetrate through the second metal layer 13, and the inner aperture of the blind hole 20 is D1.

Specifically, the blind holes 20 may be machined in the substrate 10 by laser drilling or by mechanical drilling.

Alternatively, the blind hole 20 may extend to the inside of the second metal layer 13 to facilitate control of the processing accuracy of the blind hole 20.

S300: referring to fig. 2 (b), the substrate 10 is electroplated, so that the third metal layer 30 is attached to the blind via 20, and the blind via 20 is filled with the third metal layer 30.

Specifically, after the substrate 10 is electroplated, the third metal layer 30 is attached to the blind hole 20 and fills the blind hole 20, and the material of the third metal layer 30 may be copper.

S400: referring to fig. 2 (c), a via hole 40 is formed in the substrate 10, the via hole 40 penetrates through the third metal layer 30 and the second metal layer 13, the via hole 40 and the blind hole 20 are coaxially disposed, and the inner diameter of the via hole 40 is D2, D2< D1.

Specifically, the via holes 40 may be machined in the substrate 10 by laser drilling or mechanical drilling. Since the via hole 40 and the blind hole 20 are coaxially disposed, and the inner hole diameter of the via hole 40 is D2, D2< D1, the remaining third metal layer 30 can electrically conduct the first metal layer 12 and the second metal layer 13.

Compared with the traditional mode that a through hole penetrating through the first metal layer 12, the dielectric layer 11 and the second metal layer 13 is drilled on the substrate 10, and then hole copper is plated in the through hole to electrically conduct the first metal layer 12 and the second metal layer 13, the manufacturing method for improving the aperture precision of the FPC provided by the embodiment of the application can be used for easily controlling the aperture precision of the through hole 40.

It is understood that the inner hole diameter of the via 40 is the inner hole diameter meeting the requirements of the finished FPC.

According to the manufacturing method for improving the aperture precision of the FPC, the blind holes 20 penetrating through the first metal layer 12 and the dielectric layer 11 and not penetrating through the second metal layer 13 are firstly processed on the substrate 10, then the substrate 10 is electroplated, so that the third metal layer 30 is attached to the inside of the blind holes 20, the third metal layer 30 fills the blind holes 20, finally the through holes 40 penetrating through the third metal layer 30 and the second metal layer 13 are processed on the substrate 10, the through holes 40 and the blind holes 20 are coaxially arranged, the inner aperture of the through holes 40 is D2, D2 is less than D1, the third metal layer 30 which is remained after the through holes 40 are processed can be directly used for electrically conducting the first metal layer 12 and the second metal layer 13, and hole copper does not need to be plated in the holes for electrically conducting the first metal layer 12 and the second metal layer 13, so that the inner aperture precision of the through holes 40 is easier to control, and the problem of difficult control of the hole after copper plating of the first metal layer 12 and the second metal layer 13 is plated in the holes is solved.

The manufacturing method for improving the aperture precision of the FPC can solve the problems that in a traditional FPC manufacturing method, hole copper plated in holes after electroplating is too thin, so that interlayer conduction is invalid, and hole copper plated in holes after electroplating is too thick, so that the mounting of components is affected difficultly.

It will be appreciated that if the inner hole diameter requirement of the via hole 40 of the finished FPC is greater than D and the hole copper thickness requirement of the hole wall of the via hole is D, the inner hole diameter D1 of the blind hole 20 is greater than d+ (d+d) to ensure that the inner hole diameter D2 of the via hole 40 can be greater than D while the hole copper of the hole wall (the third metal layer 30 remaining after the via hole 40 is processed on the substrate 10) satisfies the thickness D after the substrate 10 is electroplated and the via hole 40 is processed on the substrate 10.

For example, if the inner hole diameter of the via hole 40 of the finished FPC is required to be greater than 100 μm, the hole copper thickness of the hole wall of the via hole is required to be 10 μm, that is, the minimum inner hole diameter D1 of the blind hole 20 is required to be greater than 100 μm+ (10 μm+10 μm) =120 μm. In this embodiment, the inner hole diameter of the blind hole 20 is set to 130 μm, so that the hole wall thickness after electroplating and hole filling and hole re-drilling is ensured to be 10 μm, and meanwhile, the inner hole diameter of the via hole 40 of the finished FPC can reach more than 100 μm, for example, D2 is 110 μm.

Referring to fig. 3 (a) and fig. 3 (b), in order to avoid the substrate 10 from collapsing after the substrate 10 is electroplated, and further affect the accuracy of the via holes 40 formed on the substrate 10, in this embodiment, before the via holes 40 are formed on the substrate 10, the collapsible data of the substrate 10 are obtained based on all the positioning via holes 50, and then the drilling data are adjusted according to the collapsible data; the adjusted drilling data is used when the via holes 40 are processed in the substrate 10.

By adopting the scheme, the drilling data can be dynamically adjusted according to the swelling and shrinking condition of the substrate 10, so that the accuracy of the through holes 40 processed on the substrate 10 is ensured.

It will be appreciated that the obtaining of the collapsible data of the substrate 10 may compare the actual size of the substrate 10 after electroplating with the design size, and obtain the collapsible data of the substrate 10.

Optionally, when the blind hole 20 is machined on the substrate 10, a plurality of positioning through holes 50 are machined on the substrate 10, and the positioning through holes 50 penetrate through the first metal layer 12, the dielectric layer 11 and the second metal layer 13; when the substrate 10 is electroplated, the fourth metal layer 60 is attached to the inner hole wall of the positioning through hole 50; when the via holes 40 are processed on the substrate 10, the blind holes 20 and all the positioning via holes 50 are used as alignment reference points. With this arrangement, the accuracy of the via holes 40 formed in the substrate 10 can be further ensured.

It will be appreciated that a plurality of positioning through holes 50 may be machined in the substrate 10 by laser drilling or by mechanical drilling, and the blind hole 20 and the positioning through holes 50 share the same set of targets. The fourth metal layer 60 may be made of copper.

It can be further understood that after the fourth metal layer 60 is attached to the inner wall of the positioning through hole 50, the positioning through hole 50 is still in a through hole state, and still can play a role in positioning in the subsequent process.

Referring to fig. 4, alternatively, at least four positioning through holes 50 are provided, and four positioning through holes 50 are distributed in a rectangular shape. Thus, the accuracy of the via hole 40 formed in the substrate 10 can be ensured.

In the present embodiment, four positioning through holes 50 are respectively provided at four corners of the substrate 10.

Referring to fig. 2 (b), in some embodiments, the recession of the third metal layer 30 with respect to the first metal layer 12 facing away from the dielectric layer 11 is less than 5 μm.

By adopting the above scheme, the thickness of the third metal layer 30 at the edge of the opening of the via hole 40 is not enough after the via hole 40 is processed on the substrate 10, which affects the electrical conductivity.

It will be appreciated that the concavity of the third metal layer 30 with respect to the side of the first metal layer 12 facing away from the dielectric layer 11, that is, the maximum distance between the third metal layer 30 and the side of the first metal layer 12 facing away from the dielectric layer 11 along the arrangement direction (up-down direction in (b) of the figure) of the first metal layer 12 and the second metal layer 13.

Optionally, the concavity of the fourth metal layer 60 with respect to the side of the first metal layer 12 facing away from the dielectric layer 11 and the concavity of the fourth metal layer 60 with respect to the side of the second metal layer 13 facing away from the dielectric layer 11 are both less than 5 μm. By this arrangement, it is possible to avoid the shortage of the thickness of the fourth metal layer 60 at the edge of the aperture of the positioning through-hole 50 after the fourth metal layer 60 is attached to the inner wall of the positioning through-hole 50 when the substrate 10 is electroplated.

Referring to fig. 2 (a) and fig. 2 (b), in some embodiments, after the blind holes 20 are processed on the substrate 10 and before the substrate 10 is electroplated, a conductive layer (not shown) is attached to the walls of the blind holes 20 and the bottoms of the blind holes 20; when the substrate 10 is electroplated, the third metal layer 30 is attached to the conductive layer.

By adopting the scheme, the third metal layer 30 can be conveniently attached in the blind holes 20 and fill the blind holes 20 when the substrate 10 is electroplated.

Optionally, the conductive layer may be graphite or carbon powder.

Optionally, when the conductive layer is attached to the hole wall of the blind hole 20 and the hole bottom of the blind hole 20, the conductive layer is attached to the hole wall of the positioning through hole 50; when the substrate 10 is electroplated, the fourth metal layer 60 is attached to the conductive layer.

Optionally, after the conductive layer is attached to the hole wall of the blind hole 20 and the hole bottom of the blind hole 20, removing the conductive layer attached to the hole bottom of the blind hole 20; when the substrate 10 is electroplated, the third metal layer 30 is attached to the conductive layer and the second metal layer 13. By doing so, the connection strength between the third metal layer 30 and the second metal layer 13 can be improved.

In this embodiment, the conductive layer is attached to the hole wall of the blind hole 20 and the hole bottom of the blind hole 20 by the black hole/shadow method, and the conductive layer attached to the hole bottom of the blind hole 20 is removed by microetching the second metal layer 13.

Wherein the microetching control of the second metal layer 13 is 1.0 μm to 1.5 μm, such as 1.0 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm or 1.5 μm, etc., and the spraying pressure of the microetching solution is 1.2kg/cm ² -2.0kg/cm ² Such as 1.2kg/cm ² 、1.4kg/cm ² 、1.6kg/cm ² 、1.8kg/cm ² Or 2.0kg/cm ² Etc.

It can be appreciated that the micro-etching amount and the spraying pressure of the micro-etching are properly increased, so that impurities such as a conductive layer at the bottom of the blind hole 20 can be better removed, and the third metal layer 30 can be better filled in the blind hole 20 during subsequent electroplating.

Optionally, after removing the conductive layer attached to the bottom of the blind hole 20 and before electroplating the substrate 10, AOI (Automated Optical Inspection, automatic optical inspection) scanning is performed on the blind hole 20 and the positioning through hole 50, when the hole is the blind hole 20, it is confirmed that no foreign matter such as glue, carbon powder and graphite remains at the bottom of the blind hole 20 and the hole wall black hole quality is confirmed, and when the hole is the positioning through hole 50, the hole wall black hole quality is confirmed.

Referring to fig. 2 (b) and 2 (c), in some embodiments, when the substrate 10 is electroplated, a fifth metal layer 70 is attached to the first metal layer 12, and a sixth metal layer 80 is attached to the second metal layer 13; when the via hole 40 is processed on the substrate 10, the via hole 40 penetrates the fifth metal layer 70 and the sixth metal layer 80.

By adopting the above-described configuration, the fifth metal layer 70 is attached to the first metal layer 12 and the sixth metal layer 80 is attached to the second metal layer 13 simultaneously when the substrate 10 is electroplated.

It is understood that the fifth metal layer 70 and the sixth metal layer 80 may be made of copper, and the third metal layer 30, the fourth metal layer 60, the fifth metal layer 70 and the sixth metal layer 80 may be integrally connected.

Optionally, when the conductive layers are attached to the hole walls of the blind holes 20 and the hole bottoms of the blind holes 20, the conductive layers are attached to one surface of the first metal layer 12 facing away from the dielectric layer 11 and one surface of the second metal layer 13 facing away from the dielectric layer 11; when the substrate 10 is electroplated, the fifth metal layer 70 and the sixth metal layer 80 are both attached to the conductive layer. This arrangement facilitates the attachment of the fifth metal layer 70 to the first metal layer 12 and the attachment of the sixth metal layer 80 to the second metal layer 13.

In a second aspect, unlike the embodiment of the first aspect, an embodiment of the present application provides a manufacturing method for improving the aperture accuracy of an FPC, including:

s10: a substrate 10 is provided, the substrate 10 comprising a dielectric layer 11 and a first metal layer 12 and a second metal layer 13 respectively stacked on opposite sides of the dielectric layer 11.

S20: a process hole (not shown in the figure) is formed in the substrate 10, and penetrates through the first metal layer 12, the dielectric layer 11 and the second metal layer 13, and the inner diameter of the process hole is D1.

S30: the substrate 10 is electroplated such that the third metal layer 30 is attached within the process holes, and the third metal layer 30 will process Kong Tianping.

S40: a via hole 40 is processed on the substrate 10, the via hole 40 penetrates through the third metal layer 30, the via hole 40 and the process hole are coaxially arranged, and the inner hole diameter of the via hole 40 is D2, D2< D1.

According to the manufacturing method for improving the aperture precision of the FPC, the process holes penetrating through the first metal layer 12, the dielectric layer 11 and the second metal layer 13 are processed on the substrate 10, then the substrate 10 is electroplated, so that the third metal layer 30 is attached to the inside of the process holes, the third metal layer 30 is used for processing the process Kong Tianping, finally the through holes 40 penetrating through the third metal layer 30 are processed on the substrate 10, the through holes 40 are coaxially arranged with the process holes, the inner aperture of the through holes 40 is D2, D2 is less than D1, the third metal layer 30 remained after the through holes 40 are processed can be directly used for electrically conducting the first metal layer 12 and the second metal layer 13, hole copper is not required to be plated in the holes for electrically conducting the first metal layer 12 and the second metal layer 13, and accordingly the inner aperture precision of the through holes 40 is easy to control, and the problem of difficult control of the inner aperture after copper plating caused by adopting a traditional mode of plating hole copper in the holes for electrically conducting the first metal layer 12 and the second metal layer 13 is solved.

In a third aspect, embodiments of the present application provide an FPC, which is processed by the manufacturing method for improving the aperture accuracy of the FPC according to the first aspect or the second aspect.

According to the FPC provided by the embodiment of the application, the blind holes 20 penetrating the first metal layer 12 and the dielectric layer 11 and not penetrating the second metal layer 13 are processed on the substrate 10 during processing, then the substrate 10 is electroplated, so that the third metal layer 30 is attached to the blind holes 20, the third metal layer 30 fills the blind holes 20, finally the through holes 40 penetrating the third metal layer 30 and the second metal layer 13 are processed on the substrate 10, the through holes 40 and the blind holes 20 are coaxially arranged, the inner diameters of the through holes 40 are D2 and D2< D1, so that the first metal layer 12 and the second metal layer 13 can be electrically conducted by directly using the third metal layer 30 which is remained after the through holes 40 are processed, and the first metal layer 12 and the second metal layer 13 do not need to be electrically conducted by plating hole copper in the holes, thereby the inner hole diameter accuracy of the through holes 40 is easier to control, and the problem of the control of the plated copper holes caused by adopting the traditional way of electrically conducting the first metal layer 12 and the second metal layer 13 in the holes is solved.

The above embodiments are only for illustrating the technical solution of the present application, and are not limiting; although the application 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 scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.

Claims (10)

1. The manufacturing method for improving the aperture precision of the FPC is characterized by comprising the following steps of:

providing a substrate, wherein the substrate comprises a dielectric layer, and a first metal layer and a second metal layer which are respectively stacked on two opposite sides of the dielectric layer;

processing a blind hole on the substrate, wherein the blind hole penetrates through the first metal layer and the dielectric layer and does not penetrate through the second metal layer, and the inner aperture of the blind hole is D1;

electroplating the substrate to enable a third metal layer to be attached in the blind hole, and filling the blind hole by the third metal layer;

and processing a via hole on the substrate, wherein the via hole penetrates through the third metal layer and the second metal layer, the via hole and the blind hole are coaxially arranged, and the inner aperture of the via hole is D2, and D2 is less than D1.

2. The method for improving the aperture precision of the FPC according to claim 1, wherein before a via hole is processed on the substrate, the swelling and shrinking data of the substrate are acquired, and then drilling data are adjusted according to the swelling and shrinking data; and when the through hole is processed on the substrate, using the adjusted drilling data.

3. The method for improving the aperture precision of an FPC according to claim 1, wherein when a blind hole is formed in the substrate, a plurality of positioning through holes are formed in the substrate, the positioning through holes penetrating through the first metal layer, the dielectric layer and the second metal layer; when the substrate is electroplated, a fourth metal layer is attached to the inner hole wall of the positioning through hole; and when the through holes are processed on the substrate, the blind holes and all the positioning through holes are used as alignment reference points.

4. The method for improving the aperture precision of the FPC according to claim 3, wherein at least four positioning through holes are formed, and four positioning through holes are distributed in a rectangular shape.

5. The method for improving the aperture precision of an FPC according to claim 1, wherein the recession of the third metal layer with respect to the first metal layer on the side facing away from the dielectric layer is less than 5 μm.

6. The method according to any one of claims 1 to 5, wherein a conductive layer is attached to a wall of the blind hole and a bottom of the blind hole after the blind hole is formed in the substrate and before the substrate is electroplated; when the substrate is electroplated, the third metal layer is attached to the conductive layer.

7. The method according to claim 6, wherein after the conductive layer is attached to the hole wall of the blind hole and the hole bottom of the blind hole, the conductive layer attached to the hole bottom of the blind hole is removed; when the substrate is electroplated, the third metal layer is attached to the conductive layer and the second metal layer.

8. The method according to any one of claims 1 to 5, wherein a fifth metal layer is attached to the first metal layer and a sixth metal layer is attached to the second metal layer when the substrate is electroplated; and when a via hole is processed on the substrate, the via hole penetrates through the fifth metal layer and the sixth metal layer.

9. The manufacturing method for improving the aperture precision of the FPC is characterized by comprising the following steps of:

providing a substrate, wherein the substrate comprises a dielectric layer, and a first metal layer and a second metal layer which are respectively stacked on two opposite sides of the dielectric layer;

processing a process hole on the substrate, wherein the process hole penetrates through the first metal layer, the dielectric layer and the second metal layer, and the inner aperture of the process hole is D1;

electroplating the substrate to enable a third metal layer to be attached in the process hole, wherein the process is filled by the third metal layer;

and processing a via hole on the substrate, wherein the via hole penetrates through the third metal layer, the via hole and the blind hole are coaxially arranged, and the inner aperture of the via hole is D2, and D2 is less than D1.

10. An FPC, characterized in that the FPC is processed by the manufacturing method for improving the aperture accuracy of the FPC according to any one of claims 1 to 9.