An inner layer original plate, a manufacturing method of an inner layer original plate, and a printed circuit board

Abstract

The application discloses an inner layer original plate, a manufacturing method of the inner layer original plate and a printed circuit board. The inner layer original plate comprises a first carrier film, a first pure resin sheet, a base layer, a second pure resin sheet and a second carrier film which are sequentially arranged. At least one glue filling area is arranged on the base layer. Each glue filling area comprises a plurality of glue filling holes. The depth of each glue filling hole is greater than or equal to 2 oz. Each pure resin sheet comprises a tearing area and at least one reserved area. Each reserved area corresponds to each glue filling area. The outline of each reserved area is connected with the tearing area through a stamp hole. The glue filling holes can be filled with pure resin, and the phenomenon of uneven thickness of the printed circuit board can be avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of printed circuit boards, and particularly relates to an inner layer original board, a manufacturing method of the inner layer original board and a printed circuit board. BACKGROUND

[0002] The manufacturing and processing technology of a printed circuit board (PCB) has been very mature since the development of the PCB. With the diversified development of product types, new challenges are brought to the manufacturing of the PCB.

[0003] A traditional power supply board or an energy board is usually designed as 6 to 8 layers. With the development of product miniaturization, the number of layers has been increased to 12 to 16 layers. Due to the increase of the power supply demand and the increase of the number of ball grid array (BGA) structures of the printed circuit board, it is necessary to add a power supply layer or increase the copper thickness of the power supply layer to meet the power supply demand of various electronic components, and the processing difficulty of the PCB is greatly increased. Certain high-end line cards and backplanes often use 2oz or 3oz thick copper as a power supply layer. The conventional lamination method is to stack the whole prepreg according to the lamination sequence, and then perform hot pressing to form the PCB. At this time, it is easy to cause insufficient filling of the glue in the thick copper filling glue area to form a pressing cavity, and the overall board thickness is uneven, which affects the BGA flatness. SUMMARY

[0004] The present application aims to overcome the deficiencies in the prior art, and provides an inner layer original board, a manufacturing method of the inner layer original board and a printed circuit board, which can fill the glue holes with pure resin.

[0005] To achieve the above-mentioned purpose, the present application is implemented by using the following technical solutions:

[0006] In a first aspect, the present application provides an inner layer original board, which comprises a first carrier film, a first pure resin sheet, a base layer, a second pure resin sheet and a second carrier film arranged in sequence.

[0007] The base layer is provided with at least one glue filling area.

[0008] Each glue filling area comprises a plurality of glue filling holes.

[0009] The depth of each glue filling hole is greater than or equal to 2oz.

[0010] Each pure resin sheet comprises a tear-off area and at least one reserved area, each reserved area corresponds to each glue filling area, and the outline of each reserved area is connected to the tear-off area through a stamp hole.

[0011] Further, each reserved area has the same size as the corresponding glue filling area.

[0012] Further, the base layer comprises a first copper foil, a cured resin and a second copper foil arranged in sequence.

[0013] In a second aspect, the application provides a method for manufacturing an inner layer original plate, comprising the following steps:

[0014] obtaining a first carrier film, a first pure resin sheet, a base layer, a second pure resin sheet and a second carrier film;

[0015] mapping a preset ball grid array structure position onto the base layer to obtain a corresponding glue filling area, and opening a plurality of glue filling holes in the glue filling area according to the preset ball grid array structure;

[0016] mapping the glue filling area of the base layer onto the first pure resin sheet and the second pure resin sheet to obtain a corresponding reserved area, and laser stamping a hole on the outline of each reserved area;

[0017] arranging the first carrier film, the first pure resin sheet, the base layer, the second pure resin sheet and the second carrier film in sequence, and performing double-sided fast pressing to obtain an inner layer original plate with a ball grid array structure.

[0018] Further, the depth of each glue filling hole is greater than or equal to 2oz.

[0019] Further, the glue content of each pure resin sheet is 100%, and the thickness is 20-300um.

[0020] Further, the thickness of each carrier film is 200-500um.

[0021] Further, the base layer comprises a first copper foil, a cured resin and a second copper foil arranged in sequence.

[0022] Further, the glue filling area and the corresponding reserved area have the same size.

[0023] In a third aspect, the application provides a printed circuit board, comprising an upper copper foil, a lower copper foil, a first cured resin, a second cured resin and at least one inner layer original plate as described above.

[0024] The upper copper foil, the first cured resin, the second cured resin, the inner layer original plate and the lower copper foil are arranged in sequence.

[0025] Compared with the prior art, the application has the following beneficial effects:

[0026] By arranging the first pure resin sheet and the second pure resin sheet covering both sides of the base layer, each glue filling hole can be filled with pure resin. By arranging the stamp hole between the reserved area and the tear-off area, when the inner layer original plate is used as a power layer of the printed circuit board, the excess resin in the tear-off area can be conveniently removed, and the phenomenon of uneven thickness of the printed circuit board is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiment description will be briefly introduced.

[0028] Figure 1 An embodiment structure schematic diagram of the inner layer original plate of the present application is shown in the figure.

[0029] Figure 2 An embodiment structure schematic diagram of the inner layer original plate of the present application is shown in the figure.

[0030] Figure 3 An embodiment structure schematic diagram of the pure resin sheet of the present application is shown in the figure.

[0031] Figure 4 An embodiment structure schematic diagram of the printed circuit board of the present application is shown in the figure.

[0032] In the figure: 1, first carrier film, 2, first pure resin sheet, 3, base layer, 31, glue filling area, 311, glue hole, 41, reserved area, 42, tear-off area, 43, stamp hole. DETAILED DESCRIPTION

[0033] In the description of the present application, it needs to be understood that the orientation or position relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second" and the like can be explicitly or implicitly included one or more. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0034] In the description of the present application, it needs to be explained that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood through specific circumstances.

[0035] Embodiment 1

[0036] The present embodiment provides an inner layer original plate.

[0037] Reference Figure 1 The inner layer original plate of the embodiment comprises a first carrier film 1, a first pure resin sheet 2, a base layer 3, a second pure resin sheet, and a second carrier film arranged in sequence. The base layer comprises a first copper foil, a cured resin, and a second copper foil arranged in sequence.

[0038] In application, the adhesive content of each pure resin sheet is 100%, and the flowability is good, and the thickness of each pure resin sheet is 20-300 um. In actual application, each carrier film is a PET film.

[0039] Reference Figure 2 The base layer 3 is provided with at least one glue filling area 31; each glue filling area 31 comprises a plurality of glue filling holes 311. In application, those skilled in the art can set the number, position, and area size of the glue filling area 31 according to actual needs. In actual application, the depth of the glue filling hole is greater than or equal to 2oz;

[0040] Reference Figure 2 Each pure resin sheet of the embodiment comprises a tear-off area 42 and at least one reserved area 41. In application, the number, position, and area size of each reserved area 41 correspond to each glue filling area 31 one by one. In actual application, each reserved area has the same size as the corresponding glue filling area.

[0041] Reference Figure 3 The outline of each reserved area is connected to the tear-off area 42 through a stamp hole 43. In application, by pulling the tear-off area 42 hard, the stamp hole 43 can be damaged, so that the tear-off area is separated from the reserved area, and each reserved area still covers the corresponding glue filling area 31.

[0042] The first pure resin sheet and the second pure resin sheet arranged on both sides of the base layer can fill each glue filling hole with pure resin; the stamp hole arranged between the reserved area and the tear-off area can conveniently tear off the excess resin of the tear-off area when the inner layer original plate is used as the power layer of the printed circuit board, so as to avoid the phenomenon of uneven thickness of the printed circuit board.

[0043] Embodiment 2

[0044] On the basis of embodiment 1, the embodiment provides a manufacturing method of an inner layer original plate.

[0045] The manufacturing method of the inner layer original plate of the embodiment comprises the following steps:

[0046] S1 obtains a first carrier film, a first pure resin sheet, a base layer, a second pure resin sheet, and a second carrier film. The base layer comprises a first copper foil, a cured resin, and a second copper foil arranged in sequence.

[0047] In application, each pure resin sheet has a glue content of 100% and a thickness of 20-300 um. In actual application, each pure resin sheet has a thickness of 100-150 um.

[0048] In addition, each carrier film has a thickness of 200-500 um.

[0049] S2 maps the preset ball grid array structure position to the base layer to obtain a corresponding glue filling area, and opens a plurality of glue filling holes in the glue filling area according to the preset ball grid array structure.

[0050] In application, the position and size of the glue filling area and the corresponding reserved area are the same, and in addition, the depth of each glue filling hole is greater than or equal to 2 oz.

[0051] In actual application, a person skilled in the art can determine all BGA positions and sizes according to the Gerber data provided by the customer. It can be seen that the embodiment can selectively glue according to the inner layer pattern.

[0052] S3 maps the glue filling area of the base layer to the first pure resin sheet and the second pure resin sheet to obtain a corresponding reserved area, and laser stamps a hole on the outline of each reserved area.

[0053] In application, the stamp hole on the outline of the reserved area is a plurality of drill holes arranged at equal intervals, and the hole spacing is very small.

[0054] In actual application, the stamp hole divides the pure resin sheet into a reserved area and a tear-off area.

[0055] S4 sequentially arranges the first carrier film, the first pure resin sheet, the base layer, the second pure resin sheet, and the second carrier film, and performs double-sided fast pressing to obtain an inner layer original plate with a ball grid array structure.

[0056] In application, the first carrier film, the first pure resin sheet, the base layer, the second pure resin sheet, and the second carrier film are sequentially placed from top to bottom, and double-sided fast pressing is performed using a vacuum fast pressing machine. In actual application, the pressure of the vacuum fast pressing machine is set to 200-300 psi, and the temperature is set to 200℃±20℃.

[0057] The manufacturing method of the present application is simple to operate, and can greatly reduce a series of quality risks caused by insufficient BGA glue filling and reduce the scrap rate.

[0058] Example 3

[0059] The present embodiment provides a printed circuit board.

[0060] The printed circuit board of the present embodiment includes an upper copper foil, a lower copper foil, a first cured resin, a second cured resin, and at least one inner layer original plate described in Example 1.

[0061] Reference Figure 4The upper copper foil, the first cured resin, the second cured resin, the inner layer original plate and the lower copper foil are sequentially arranged.

[0062] In the application, when the inner layer original plate is used as the power layer of the printed circuit board, the first carrier film 1 and the second carrier film of the inner layer original plate are first torn off. In addition, since the pure resin of the reserved area flows into the filling hole, the tearing-off area of the first pure resin sheet 2 and the second pure resin sheet is torn off to avoid the phenomenon that the thickness of the printed circuit board is uneven due to the uneven thickness of the reserved area and the tearing-off area.

[0063] In actual application, the first cured resin and the second cured resin are arranged on both sides of the inner layer original plate to insulate the inner layer original plate from the upper copper foil and the lower copper foil.

[0064] In the actual application, the first cured resin and the second cured resin are arranged on both sides of the inner layer original plate to insulate the inner layer original plate from the upper copper foil and the lower copper foil.

[0065] In summary, the pure resin sheet is used in the application to ensure that the thick copper filling area can be fully filled, and to solve the problem of pressing cavity caused by insufficient filling. In addition, before the printed circuit board is stacked, the BGA is filled with pure resin on the inner layer substrate, which reduces the filling height of the base layer and reduces the difficulty of filling the cured resin, thereby improving the product pass rate.

[0066] The embodiments of the application are described above in combination with the drawings, but the application is not limited to the above specific embodiments, and the above specific embodiments are only illustrative and not restrictive. Those skilled in the art can make many forms under the inspiration of the application without departing from the purpose of the application and the scope protected by the claims, and these are all within the protection of the application.

Claims

1. An inner layer substrate, characterized in that, It includes a first carrier film (1), a first pure resin sheet (2), a base layer (3), a second pure resin sheet, and a second carrier film arranged in sequence; At least one glue-filling area (31) is provided on the base layer (3); Each of the filling areas (31) includes a plurality of filling holes (311); The depth of each filling hole is greater than or equal to 2 oz; Each of the pure resin sheets includes a tear-off area (42) and at least one retention area (41), and each retention area (41) corresponds one-to-one with each glue-filling area (31); The outlines of each retention area and the tear-off area (42) are connected by the stamp perforation (43); Each of the aforementioned retention areas has the same size as the corresponding filling area; The base layer comprises a first copper foil, a cured resin, and a second copper foil arranged in sequence; The method for manufacturing the inner layer substrate includes the following steps: Obtain a first carrier film, a first pure resin sheet, a base layer, a second pure resin sheet, and a second carrier film; The preset ball grid array structure position is mapped onto the base layer to obtain the corresponding glue filling area, and multiple glue filling holes are opened in the glue filling area according to the preset ball grid array structure. The glue-filling area of ​​the base layer is mapped onto the first pure resin sheet and the second pure resin sheet to obtain the corresponding retention area, and stamp holes are laser-engraved on the outline of each retention area. The first carrier film, the first pure resin sheet, the base layer, the second pure resin sheet, and the second carrier film are sequentially arranged and subjected to double-sided fast pressing to obtain an inner layer substrate with a ball grid array structure. The outlines of each retention area and the tear-off area are connected by the stamp perforation; pulling the tear-off area can break the stamp perforation, causing the tear-off area to detach from the retention area, while each retention area still covers the corresponding glue-filled area. Each of the aforementioned pure resin sheets has a 100% resin content and a thickness of 20-300 μm.

2. The inner layer substrate according to claim 1, characterized in that, The thickness of each of the carrier films is 200-500 μm.

3. A printed circuit board, characterized in that, It includes an upper copper foil, a lower copper foil, a first cured resin, a second cured resin, and at least one inner layer substrate as described in claim 1; The upper copper foil, the first cured resin, the inner original plate, the second cured resin, and the lower copper foil are arranged in sequence.

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