CN211531434U

CN211531434U - Step type circuit board

Info

Publication number: CN211531434U
Application number: CN201922460852.XU
Authority: CN
Inventors: 卢耀普; 卢振华; 陈斌; 黄治国; 黄晓峰
Original assignee: Yuehu Crystal Core Circuit Suzhou Co ltd
Current assignee: Yuehu Crystal Core Circuit Suzhou Co ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-09-18
Anticipated expiration: 2029-12-31

Abstract

The utility model discloses a notch cuttype circuit board, including the basic unit, be provided with at least one deck stair structure in the basic unit, stair structure includes photosensitive resin layer and routing layer, the routing layer subsides in on the photosensitive resin layer, at least one side of stair structure is the step face, photosensitive resin layer on the step face has plated the copper foil, the routing layer with the help of the copper foil is connected with the routing layer or the basic unit of next floor. The utility model discloses a step face intercommunication each layer circuit of notch cuttype structure can need not drill completely, directly utilizes photosensitive resin as the insulating layer in addition, has saved the pressfitting technology, has saved processing cost and equipment input by a wide margin.

Description

Step type circuit board

Technical Field

The utility model relates to a circuit board technique especially relates to a notch cuttype circuit board.

Background

In the prior art, the conduction between layers of the multilayer circuit board is realized by mechanical drilling or laser drilling. Specifically, a connecting pad is designed at a position where each layer of the circuit board is preset to be conducted, the layers are pressed together and then need to be aligned in position, a through hole or a blind hole is drilled at the position, and then the layers are conducted in a mode of copper plating, copper plating and hole filling and the like in the hole. The blind holes and the buried holes are integrally connected in a layer-by-layer overlapping mode after being connected in a single layer mode. The wiring density of the circuit board is very high, each layer is very thin, the expansion deformation amount is large, the interlayer alignment precision tolerance control is more and more difficult, the drilling belongs to secondary positioning, and the drilling machine has precision tolerance, so the drilling conduction technology is complex in process, the precision control requirement is high in difficulty, and the cost is high.

Disclosure of Invention

An object of the utility model is to provide a notch cuttype circuit board that need not drilling and pressfitting technology.

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

According to the utility model discloses an aspect provides a notch cuttype circuit board, including the basic unit, be provided with at least one deck stair structure in the basic unit, stair structure includes photosensitive resin layer and routing layer, the routing layer laminate in on the photosensitive resin layer, at least one side of stair structure is the step face, photosensitive resin layer on the step face has plated the copper foil, the routing layer with the help of the copper foil is connected with the routing layer or the basic unit of one deck down.

In one embodiment, the photosensitive resin layer of the stepped circuit board is provided with blind holes and/or buried holes communicated with the upper layer and the lower layer, and the inner walls of the blind holes and/or the buried holes are plated with copper.

In one embodiment, the step surface of the stepped circuit board is a vertical plane, an inclined plane or a curved surface.

In one embodiment, the photosensitive resin layer of the step circuit board is cured on the underlying base layer or routing layer.

In one embodiment, the photosensitive resin layer on the step surface of the step-shaped circuit board is fully covered with a copper layer.

In one embodiment, the photosensitive resin layer on the step surface of the step-shaped circuit board is partially covered with copper layers communicating the upper and lower surfaces.

In one embodiment, the thickness of the copper foil layer of the step circuit board is 25 μm to 35 μm.

In one embodiment, the thickness of the photosensitive resin layer of the step circuit board is 10 μm to 15 μm.

In one embodiment, the step structure of the uppermost layer of the step-type circuit board is covered with a solder mask layer.

The embodiment of the utility model provides a beneficial effect is: each layer of circuit is communicated through the step surface of the stepped structure, drilling can be completely omitted, in addition, photosensitive resin is directly used as an insulating layer, a pressing process is omitted, and processing cost and equipment investment are greatly saved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

The above features and advantages of the present invention will be better understood upon reading the detailed description of embodiments of the present disclosure in conjunction with the following drawings. In the drawings, components are not necessarily drawn to scale, and components having similar relative characteristics or features may have the same or similar reference numerals.

Fig. 1 is a schematic cross-sectional view of an embodiment of the invention;

fig. 2 is a schematic perspective view of an embodiment of the present invention;

fig. 3 is a schematic perspective view of another embodiment of the present invention;

wherein: 1-a base layer; 2-a step structure; 21-a photosensitive resin layer; 22-routing layer; 21 a-copper foil; 3, blind holes; 4-hole burying; 5-a solder mask layer; 201-buried via line; 301-via line.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It is noted that the aspects described below in connection with the figures and the specific embodiments are only exemplary and should not be understood as imposing any limitation on the scope of the present invention.

As shown in fig. 1, the embodiment of the utility model discloses notch cuttype circuit board, including basic unit 1, be provided with at least one deck stair structure 2 in the basic unit, stair structure 2 includes photosensitive resin layer 21 and routing layer 22, and routing layer 22 pastes and covers on photosensitive resin layer 21, and basic unit or routing layer under it is received in at least one side of stair structure 2 to form the step face. The photosensitive resin layer 21 is plated with a copper foil 21a on the step surface, and the wiring layer 22 is connected to the next wiring layer or base layer 1 via the copper foil 21 a. The utility model discloses technical scheme passes through each layer circuit of structure side intercommunication of notch cuttype, can not need drilling completely, and the pressfitting technology has been saved as the insulating layer to the direct photosensitive resin solidification of utilizing in addition, has saved processing cost and equipment input by a wide margin.

In a possible embodiment, part of the electrical connection between routing layers 22 may also be realized by blind or buried vias. Therefore, the blind holes 3 and/or the buried holes 4 communicating the upper and lower layers can be provided on the photosensitive resin layer 22, and the inner walls of the blind holes 3 and/or the buried holes 4 are plated with copper.

The step surface can be adjusted to be a vertical plane, an inclined plane or a curved surface through a developing process and grinding. The step surface is plated with copper either completely or partially. If the step face on one side is plated with copper completely, the lines to be connected with each other can be connected to the step face. If the portion on the step surface is plated with copper, the function of a plurality of lines can be realized, and the structure can be shown as figure 2. When the part on the step surface is plated with copper, the conductive layer of the part which does not need to be plated with copper can be polished off, and the remaining part is plated with copper, so that the effect of a plurality of circuits can be formed. If the copper foils 21a of the upper and lower step surfaces are not communicated to form the buried via line 201 in fig. 2, the function is similar to the original buried via. As shown in fig. 3, the copper foils 21a on the upper and lower step surfaces may be connected to form a through via line 301 instead of the original via hole.

In the step-type circuit board, the photosensitive resin layer 21 directly serves as an insulating layer, and the photosensitive resin layer 21 is cured on a base layer or a wiring layer therebelow.

In the present embodiment, the copper foil layer 22 has a thickness of 25 μm. The thickness of the photosensitive resin layer 21 was 13 μm.

Preferably, the uppermost step structure is covered with a solder resist layer 5.

The step type circuit board can be manufactured by the following steps:

s1, coating a photosensitive resin layer on the base layer, wherein the base layer can be a substrate with a copper foil, a release film or a substrate which is drilled and coppered for conduction and is provided with a double-sided circuit, or a wiring layer with a circuit. In this embodiment, a copper foil is used as a base layer, and a photosensitive resin layer having a thickness of 11 μm to 13 μm is uniformly coated on the base layer using a coating roller, and since the photosensitive resin layer is also used as an insulating layer in this method, the thickness thereof should be slightly increased, so that the thickness of 13 μm is preferably used in this embodiment. The photosensitive resin is gradually used in industrial production in recent years, and the components of the photosensitive resin used in the technical scheme adopt the prior art, so that the detailed description is omitted.

S2, selectively photo-curing the photosensitive resin layer, and curing the photosensitive resin except for the holes and the steps to form an insulating layer: drawing a hole and step pattern on a photographic film by a photoplotter, covering the photographic film on a photosensitive resin layer, and irradiating the photosensitive resin layer with ultraviolet rays so that the photosensitive resin at a portion other than the hole and the step is cured to form an insulating layer. The step surface can be a vertical plane or an arc surface, and the shape of the step surface can be controlled by drawing different shapes on the photographic film.

It should be noted that the "hole" described herein does not refer to any of a through hole, a buried hole or a blind hole, and for example, if a through hole needs to be processed, a hole needs to be developed at a corresponding position on each insulating layer, and a hole needs to be etched at a corresponding position on a copper layer, so that the through hole can be formed.

S3, developing away the uncured photosensitive resin of the hole and the step portion: the circuit board is placed in developing solution, the photosensitive resin in the hole and the step part is dissolved, and the solidified resin is continuously attached to the surface of the copper foil.

S4, copper plating on the inner wall of the hole, copper plating on the step surface, and copper plating on the upper surface of the insulating layer to form a next routing layer: acid copper deposition, namely uniformly depositing a conductive layer inside the hole, on the side surface of the step and on the upper surface of the insulating layer; and (4) copper plating, namely copper plating is carried out on the inner part of the blind hole, the side surface of the step and the upper surface of the insulating layer.

And S5, manufacturing a circuit pattern on the next wiring layer. The steps of S1 to S4 are still used for forming the wiring pattern, except that when the photosensitive resin layer is selectively photocured, the corresponding portion of the wiring is further cured, and an etching step is added after development, and the copper layer without the protection of the photosensitive resin is etched away to leave the wiring and form holes and steps, and then copper plating is performed.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

While, for purposes of simplicity of explanation, the methodologies are shown and described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance with one or more embodiments, occur in different orders and/or concurrently with other acts from that shown and described herein or not shown and described herein, as would be understood by one skilled in the art.

The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

The above description is only a preferred example of the present application and should not be taken as limiting the present application, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present application should be included in the scope of the present application.

Claims

1. The utility model provides a notch cuttype circuit board which characterized in that: including the basic unit, be provided with one deck at least stair structure in the basic unit, stair structure includes photosensitive resin layer and routing layer, the routing layer subsides in on the photosensitive resin layer, at least one side of stair structure is the step face, the photosensitive resin layer on the step face has plated the copper foil, the routing layer with the help of the copper foil is connected with the routing layer or the basic unit of lower one deck.

2. A stepped circuit board as defined in claim 1, wherein: the photosensitive resin layer is provided with blind holes and/or buried holes communicated with the upper layer and the lower layer, and the inner walls of the blind holes and/or the buried holes are plated with copper.

3. A stepped circuit board as defined in claim 1, wherein: the step surface is a vertical plane, an inclined plane or a curved surface.

4. A stepped circuit board as defined in claim 1, wherein: the photosensitive resin layer is solidified on the base layer or the routing layer below the photosensitive resin layer.

5. A stepped circuit board as defined in claim 1, wherein: and the photosensitive resin layer on the step surface is fully covered with a copper layer.

6. A stepped circuit board as defined in claim 1, wherein: and the photosensitive resin layer on the step surface is partially covered with a copper layer communicated with the upper surface and the lower surface.

7. A stepped circuit board as defined in claim 1, wherein: the thickness of the copper foil layer is 25-35 μm.

8. A stepped circuit board as defined in claim 1, wherein: the thickness of the photosensitive resin layer is 10-15 μm.

9. A stepped circuit board as defined in claim 1, wherein: the step structure of the uppermost layer is covered with a solder mask layer.