CN115413127A

CN115413127A - Circuit board and manufacturing method thereof

Info

Publication number: CN115413127A
Application number: CN202110592187.9A
Authority: CN
Inventors: 唐昌胜
Original assignee: Shennan Circuit Co Ltd
Current assignee: Shennan Circuit Co Ltd
Priority date: 2021-05-28
Filing date: 2021-05-28
Publication date: 2022-11-29

Abstract

The application discloses a circuit board and a manufacturing method thereof. The manufacturing method of the circuit board comprises the following steps: the manufacturing method of the circuit board comprises the following steps: preparing a circuit board to be processed, wherein the circuit board to be processed comprises a substrate and a conductive circuit layer arranged on the surface of at least one side opposite to the substrate, and the conductive circuit layer comprises at least one component mounting part; covering an insulating layer on the conductive circuit layer; arranging a window in the region of the insulating layer corresponding to the element mounting part so that the element mounting part is exposed from the window; and a conductive connecting layer is arranged in the window, is connected to the surface of one side of the element mounting part, which is far away from the substrate, and is electrically connected with the element mounting part so as to be electrically connected with a preset electronic element.

Description

Circuit board and manufacturing method thereof

Technical Field

The application belongs to the technical field of printed circuit boards, and particularly relates to a circuit board and a manufacturing method thereof.

Background

In the prior PCB, the PCB may generally include a substrate and a conductive trace layer disposed on a surface of the substrate. The conductive line layer is generally formed by patterning a predetermined conductive layer, and the conductive line layer may include a plurality of conductive lines, and the plurality of conductive lines may form a predetermined pattern.

At least one of the conductive lines can be used as a welding pad for welding with an electronic element, so that the electronic element can be fixedly connected with the PCB, and the electronic element can be electrically connected with the conductive lines on the PCB, thereby forming a preset functional circuit.

In the prior art, after patterning a preset conductive layer to form a conductive circuit layer with a plurality of conductive circuits, ink can be coated on the surface of the conductive circuit layer on the surface layer of the PCB for protection, and pads therein need to be exposed. In order to facilitate subsequent soldering operations, it is necessary to provide a soldering layer on the surface of the pad, for example, a nickel layer, a gold layer, or a tin layer is formed on the surface of the pad by electroless nickel/gold plating, electrolytic gold plating, electroless tin plating, electrolytic tin plating, or the like.

Further, if a nickel layer or a gold layer is formed on the surface of the pad, solder such as solder paste needs to be arranged on the nickel layer or the gold layer during subsequent welding, which results in a more complex processing technology; if a tin layer is formed on the surface of the bonding pad, the problem of ink falling off can be caused when chemical tin plating or electrolytic tin plating processing is carried out; and the scheme of forming the tin layer on the surface of the bonding pad is not suitable for the printed circuit board with high-density wiring hole design.

Disclosure of Invention

The present application provides a circuit board and a method for manufacturing the same to solve the above technical problems.

In order to solve the technical problem, the application adopts a technical scheme that: provided is a method of manufacturing a circuit board, including:

preparing a circuit board to be processed, wherein the circuit board to be processed comprises a substrate and a conductive circuit layer arranged on the surface of at least one side opposite to the substrate, and the conductive circuit layer comprises at least one component mounting part;

covering an insulating layer on the conducting circuit layer;

arranging a window in the region of the insulating layer corresponding to the element mounting part, so that the element mounting part is exposed from the window;

set up electrically conductive articulamentum in the windowing, electrically conductive articulamentum connect in the component mounting department deviates from a base plate side surface and with component mounting department electricity is connected to be connected with predetermineeing the electronic component electricity.

Optionally, the step of covering the conductive circuit layer with an insulating layer includes:

covering a prepreg with a preset thickness on one side of the conducting circuit layer, which is far away from the substrate;

and fixedly connecting the prepreg with the circuit board to be processed in a hot pressing manner.

Optionally, the step of providing a window in a region of the insulating layer corresponding to the component mounting portion includes:

and arranging a window in the region of the insulating layer corresponding to the component mounting part by adopting a laser ablation, ion cutting, ion polishing or water jet cutting mode.

Optionally, the step of providing a conductive connection layer in the window includes:

electroplating to form an electroplated layer in the window; or alternatively

And filling conductive adhesive in the window to form a conductive adhesive layer.

Optionally, the step of electroplating to form an electroplated layer in the window comprises:

arranging a photosensitive film on one side of the insulating layer, which is far away from the conducting circuit layer;

removing the area of the photosensitive film corresponding to the window so as to expose the element mounting part from the photosensitive film;

electroplating to form an electroplated layer on the surface of one side of the component mounting part, which is far away from the substrate;

and removing the photosensitive film.

Optionally, the electroplating layer or the conductive adhesive layer does not extend beyond the surface of the insulating layer on the side away from the conductive circuit layer.

In order to solve the technical problem, the application adopts a technical scheme that: providing a circuit board, the circuit board comprising:

a substrate;

the conductive circuit layer is arranged on at least one side surface of the substrate and comprises at least one component mounting part;

the insulating layer is arranged on one side, away from the substrate, of the conducting circuit layer, and a window is formed in the region, corresponding to the component mounting part, of the insulating layer; and

the conductive connecting layer is at least partially arranged in the window and fixedly connected and electrically connected with the element mounting part; the conductive connecting layer is used for fixedly connecting with a preset electronic element and electrically connecting the preset electronic element with the element mounting part.

Optionally, the conductive connection layer is an electroplated layer plated on the component mounting part; or a conductive adhesive layer arranged on the component mounting part.

Optionally, the thickness of the conductive connection layer is no greater than two-thirds of the depth of the fenestration.

Optionally, the circuit board further comprises electronic components;

the electronic element is fixedly connected and electrically connected with the element mounting part through the conductive connecting layer.

The beneficial effect of this application is: in the scheme, the insulating layer formed by the insulating sheet covers all conductive circuits on the conductive circuit layer, so that compared with the scheme of coating ink on the conductive circuit layer, the formed insulating layer has good stability and is not easy to fall off when the surface coating processing of the component mounting part and the welding or bonding operation of the electronic component are carried out subsequently; in addition, the insulating layer can only enable the conducting circuit corresponding to the component mounting part to be exposed from the window on the insulating layer, and the conducting connecting layer is arranged in the window, so that the conducting circuit layer on the surface layer of the circuit board can be protected, the conducting connecting layer in the window can be prevented from overflowing during welding or bonding operation, the surrounding circuits cannot be affected during welding or bonding operation, and the circuit board can be suitable for high-density wiring.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without inventive efforts, wherein:

fig. 1 is a schematic flow chart illustrating an embodiment of a method for manufacturing a circuit board according to the present application;

FIGS. 2 a-2 e are schematic flow charts illustrating another embodiment of a method for manufacturing a circuit board according to the present application;

fig. 3 is a schematic structural diagram of an embodiment of a circuit board provided in the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that if directional indications (such as up, down, left, right, front, back, 8230; \8230;) are referred to in the embodiments of the present application, the directional indications are only used to explain the relative positional relationship between the components, the motion situation, etc. in a specific posture (as shown in the attached drawings), and if the specific posture is changed, the directional indications are correspondingly changed.

In addition, if there is a description of "first", "second", etc. in the embodiments of the present application, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between the embodiments may be combined with each other, but must be based on the realization of the technical solutions by a person skilled in the art, and when the technical solutions are contradictory to each other or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope claimed in the present application.

Referring to fig. 1, fig. 1 is a schematic flow chart illustrating a method for manufacturing a circuit board according to an embodiment of the present disclosure.

The manufacturing method of the circuit board specifically comprises the following steps:

s110: preparing a circuit board to be processed, wherein the circuit board to be processed comprises a substrate and a conductive circuit layer arranged on the surface of at least one side opposite to the substrate, and the conductive circuit layer comprises at least one component mounting part.

The circuit board to be processed can comprise a substrate and a conductive circuit layer arranged on at least one surface of the substrate opposite to the substrate.

The substrate may be made of an insulating material, and for example, the substrate may be made of a resin material. Or the reinforced material can be soaked with resin adhesive and is prepared by the processes of drying, cutting, overlapping and the like, thereby improving the strength of the substrate.

When the preparation of the substrate is completed, a conductive line layer may be provided on the surface of the substrate. The conductive line layer may include a plurality of conductive lines disposed at intervals. The plurality of conductive lines arranged at intervals can form a preset conductive pattern. The conductive circuit layer may be formed by providing a conductive layer on the substrate and then etching the conductive layer. The conductive circuit layer may be made of, but not limited to, copper, aluminum, iron, nickel, gold, silver, platinum group, chromium, magnesium, tungsten, molybdenum, lead, tin, indium, zinc, or alloys thereof.

In this embodiment, the conductive trace layer includes at least one component mounting portion. Specifically, at least one of the plurality of conductive traces may be provided as a component mounting portion and may be configured to be electrically connected to an electronic component, so that the electronic component and the conductive trace layer on the circuit board to be processed may constitute a predetermined functional circuit.

The component mounting part can be a conductive circuit layer adhered to the surface layer of the circuit board to be processed; the further component mounting part also can comprise a conductive circuit layer attached to the surface layer of the circuit board to be processed and a conductive hole penetrating through the conductive circuit layer.

The circuit board to be processed can be a single-layer circuit board, namely the circuit board to be processed comprises a layer of substrate and a conductive circuit layer arranged on the surface of at least one side of the substrate.

Or, the circuit board to be processed may also be a multilayer circuit board, that is, the circuit board to be processed may be formed by sequentially and alternately stacking at least two layers of substrates and at least two layers of conductive circuit layers. The component mounting part is arranged on the conductive circuit layer on the surface layer of the circuit board to be processed.

S120: and covering the insulating sheet on the conductive circuit layer to form an insulating layer.

After the preparation of the circuit board to be processed is completed, an insulating layer can be further covered on the conductive circuit layer.

The insulating layer may be formed on the conductive circuit layer by thermally pressing insulating sheets such as prepregs. The insulating layer can be set to have a certain thickness so as to ensure that the prepreg is covered on the conductive circuit layer to be hot-pressed, so that the formed insulating layer is covered on one side of the conductive circuit layer departing from the substrate and completely covers all conductive circuits in the conductive circuit layer.

S130: and arranging a window in the region of the insulating layer corresponding to the element mounting part so that the element mounting part is exposed from the window.

After step S120 is completed, step S130 may be further completed, that is, a window is disposed in a region of the insulating layer corresponding to the component mounting portion, so that the component mounting portion is exposed from the window.

In the step, a windowing region corresponding to the component mounting portion of the insulating layer may be provided by laser ablation, ion cutting, ion polishing or water jet cutting, so that the component mounting portion is exposed from the windowing region.

The conductive circuit layer may be covered and protected by the insulating layer.

Wherein, optionally, the window on the insulating layer may be sized to match with the conductive line corresponding to the component mounting portion.

Specifically, the size of the window on the insulating layer may be set to be the same as the size of the conductive line corresponding to the component mounting portion, and the outer profile is also the same.

Alternatively, the size of the window in the insulating layer may be set to be slightly larger than the size of the conductive line corresponding to the component mounting portion. In this embodiment, it is necessary to ensure that the opening only exposes the conductive traces corresponding to the component mounting portion.

Alternatively, in other embodiments, the size of the window in the insulating layer may be set to be slightly smaller than the size of the conductive line corresponding to the component mounting portion. That is, the insulating layer may cover an edge region of the conductive trace corresponding to the component mounting portion, and expose a center region of the conductive trace corresponding to the component mounting portion from the window.

S: and a conductive connecting layer is arranged in the window, is connected to the surface of one side of the element mounting part, which is far away from the substrate, and is electrically connected with the element mounting part so as to be electrically connected with a preset electronic element.

In this step, a conductive connection layer may be disposed in the opening, wherein the conductive connection layer is connected to a surface of the component mounting portion away from the substrate and electrically connected to the component mounting portion, so as to be electrically connected to a predetermined electronic component.

In this embodiment, electrically conductive articulamentum can be for setting up the welding layer in the windowing, and wherein, electrically conductive articulamentum can be welding material such as tin, promptly, and predetermined electronic component can weld with electrically conductive articulamentum and link firmly to can realize this electronic component and component installation department electricity and be connected.

Or the conductive connecting layer can also be a conductive adhesive layer arranged in the window, and the preset electronic element can be bonded and fixedly connected with the conductive connecting layer, so that the electronic element can be electrically connected with the element mounting part. Wherein, conductive adhesive layer can adopt conducting resin such as UV glue to form, and this electronic component then can adopt hot pressing's mode to be connected with conductive adhesive layer, when conductive adhesive layer adopted UV glue, then can further adopt UV light struck to make conductive adhesive layer and this electronic component then link firmly and the electricity is connected.

Therefore, in the application, the insulating layer formed by the insulating sheet covers all the conductive circuits on the conductive circuit layer, so that compared with the scheme of coating ink on the conductive circuit layer, the formed insulating layer has good stability and is not easy to fall off when the surface coating processing of the component mounting part and the welding or bonding operation of the electronic component are carried out subsequently; in addition, the insulating layer can only enable the conducting circuit corresponding to the component mounting part to be exposed from the window on the insulating layer, and the conducting connecting layer is arranged in the window, so that the conducting circuit layer on the surface layer of the circuit board can be protected, the conducting connecting layer in the window can be prevented from overflowing when welding or bonding operation is carried out, peripheral circuits cannot be affected when welding or bonding operation is carried out, and the insulating layer can be suitable for the circuit board with high-density wiring.

Please refer to fig. 2 a-2 e. Fig. 2a to fig. 2e are schematic flow charts of another embodiment of a method for manufacturing a circuit board provided in the present application.

1. preparing a circuit board to be processed.

Please refer to fig. 2a. In this embodiment, the circuit 10 to be processed is a single-layer board, and the circuit 10 to be processed includes a substrate 110 and two conductive circuit layers 120 respectively disposed on two opposite sides of the substrate 110. The two conductive trace layers 120 on opposite sides of the substrate 110 include a plurality of conductive traces 121, and at least one conductive trace layer 120 has a component mounting portion 122 disposed therein.

In the present embodiment, similarly, the component mounting portions 122 may be conductive traces 121 provided on the surface of the substrate 110; alternatively, the component mounting portion 122 may include a conductive trace 121 disposed on the surface of the substrate 110, and a conductive via (not shown) penetrating through the conductive trace 121.

The multiple conductive circuit layers 120 in the circuit board 10 to be processed may be electrically connected through the conductive portion 101 penetrating through the substrate 110, so as to form a predetermined functional circuit.

2. And covering the insulating sheet on the circuit board to be processed to form an insulating layer.

Please refer to fig. 2b. In this step, an insulating sheet may be placed on one side surface of the circuit board 10 to be processed to form the insulating layer 130. The insulating layer 130 may cover the conductive trace layer 120 provided with the component mounting portion 122. The insulating sheet may be a prepreg, and the prepreg may be hot-pressed on a surface of one side of the circuit board 10 to be processed by using a hot-pressing method.

Specifically, the insulating layer 130 may be formed by covering an insulating sheet on one side surface of the circuit board 10 to be processed with a press-fit sheet. Wherein, the pressfitting piece can be the type diaphragm or also can be the metal diaphragm promptly.

Through establishing the insulating piece lid on waiting to process circuit board 10 side surface, and deviate from waiting to process circuit board 10 side surface with the pressfitting piece setting at the insulating piece, and then carry out the hot pressing to can be fixed with insulating piece and waiting to process circuit board 10 hot pressing. In this scheme, adopt the pressfitting piece to carry out the thermocompression bonding, can ensure the roughness that forms insulating layer 130.

3. A window is formed in the insulating layer.

Please refer to fig. 2c. In this step, a window 131 may be opened at a position corresponding to the component mounting portion 122 on the circuit board 10 to be processed, so that the component mounting portion 122 is exposed from the window 131. The setting manner and size of the window 131 can refer to the foregoing, and are not described herein again.

Wherein, it needs to be noted that, when the laminating sheet is a release film, the laminating sheet can be torn off before the window is opened; or when the laminated sheet is a metal film, it can be etched away before windowing.

4. And covering a photosensitive film on one side of the insulating layer, which is far away from the conductive circuit layer.

Please refer to fig. 2d. In this step, the insulating layer 130 may be covered with the photosensitive film 160 on a side away from the conductive trace layer 120. The photosensitive film 160 may be used to protect the insulating layer 130 during the subsequent plating of the conductive connection layer 150.

It should be noted that through holes are also required to be formed in the photosensitive film 160 at positions corresponding to the windows 131.

5. A conductive connection layer is disposed within the fenestration.

Referring to fig. 2e, in this step, a conductive connection layer 150 may be further formed in the window 131. The conductive connection layer 150 may be a plating layer formed in the window 131 by electroplating or chemical plating, wherein in order to avoid the plating layer overflowing during soldering of the electronic component, it is required to ensure that the conductive connection layer 150 does not exceed the surface of the insulating layer 130 on the side away from the conductive line layer 120. Wherein the plating layer may be a tin plating layer.

Wherein, optionally, the thickness of the conductive connection layer 150 may be set not to exceed two thirds of the depth of the open window 131.

Alternatively, before the conductive connection layer 150 is formed by electroplating, the inner wall of the window 131 may be blackened or blackened to form a plating layer on the inner wall of the window 131.

6. The photosensitive film is removed.

After the conductive connection layer is completely disposed in the window, the remaining photosensitive film 160 may be removed. The photosensitive film 160 may be a dry film or a wet film, or other release films.

Furthermore, the application also provides a circuit board. Wherein, the circuit board can be manufactured by the method as described in any of the foregoing embodiments.

Specifically, please refer to fig. 3, wherein fig. 3 is a schematic structural diagram of an embodiment of a circuit board provided in the present application.

The circuit board 20 includes a substrate 210 and a conductive trace layer 220 disposed on at least one side surface of the substrate 210. The conductive trace layer 220 is provided with an insulating layer 230 on a side away from the substrate 210.

The conductive trace layer 220 may also include a plurality of conductive traces 221, and at least one of the conductive traces 221 may form a component mounting portion 222, and the component mounting portion 222 may be used to electrically connect to a predetermined electronic component.

The insulating layer 230 is the same as the above solution, and may also be formed by thermally pressing an insulating sheet on the conductive trace layer 220, and the insulating layer 230 has a window 231 at a position corresponding to the component mounting portion 222, and a conductive connection layer 240 is disposed in the window, and the conductive connection layer 240 is connected to the component mounting portion 222.

Optionally, the conductive connecting layer 240 does not extend beyond a surface of the insulating layer 230 facing away from the substrate 210. In a preferred embodiment, the conductive connection layer 240 does not extend more than two-thirds of the depth of the window 231.

The preset electronic element may be an electronic element such as a resistor, an inductor, a capacitor, or a chip. The electronic component may be a fitting type electronic component, or may also be an electronic component with pins. When the electronic device is a bonded type, the device mounting portion 222 may correspond to the conductive trace 221 on one side surface of the substrate 210; when the electronic component is a plug-in type electronic component with pins, the component mounting portion 222 may further be provided with conductive holes for the pins of the electronic component to be plugged and matched.

In summary, in the scheme of the application, the insulating layer formed by the insulating sheet covers all the conductive circuits on the conductive circuit layer, so that compared with the scheme of coating ink on the conductive circuit layer, the insulating layer formed by the insulating sheet has good stability and is not easy to fall off when the surface plating layer processing of the component mounting part and the welding or bonding operation of the electronic component are carried out subsequently; in addition, the insulating layer can only enable the conducting circuit corresponding to the component mounting part to be exposed from the window on the insulating layer, and the conducting connecting layer is arranged in the window, so that the conducting circuit layer on the surface layer of the circuit board can be protected, the conducting connecting layer in the window can be prevented from overflowing during welding or bonding operation, the surrounding circuits cannot be affected during welding or bonding operation, and the circuit board can be suitable for high-density wiring.

The above embodiments are merely examples, and not intended to limit the scope of the present disclosure, and all modifications, equivalents, and flow charts using the contents of the specification and drawings of the present disclosure, or their direct or indirect application to other related arts, are included in the scope of the present disclosure.

Claims

1. A method for manufacturing a circuit board, comprising:

preparing a circuit board to be processed, wherein the circuit board to be processed comprises a substrate and a conductive circuit layer arranged on the surface of at least one side, opposite to the substrate, of the substrate, and the conductive circuit layer comprises at least one component mounting part;

covering an insulating sheet on the conducting circuit layer to form an insulating layer;

2. The method for manufacturing a circuit board according to claim 1, wherein the step of covering the conductive trace layer with an insulating layer includes:

3. The method for manufacturing a circuit board according to claim 2, wherein the step of providing a window in a region of the insulating layer corresponding to the component mounting portion includes:

4. The method for manufacturing a circuit board according to claim 1, wherein the step of providing a conductive connection layer in the window includes:

electroplating in the window to form an electroplated layer; or alternatively

5. The method for manufacturing a circuit board according to claim 4, wherein the step of plating a plating layer in the window includes:

and removing the photosensitive film.

6. The method of manufacturing a circuit board according to claim 4,

the electroplated layer or the conductive adhesive layer does not exceed the surface of one side of the insulating layer, which is far away from the conductive circuit layer.

7. A circuit board, comprising:

a substrate;

the conductive connecting layer is at least partially arranged in the windowing, fixedly connected with the element mounting part and electrically connected with the element mounting part; the conductive connecting layer is used for fixedly connecting with a preset electronic element and electrically connecting the preset electronic element with the element mounting part.

8. The circuit board of claim 7,

the conductive connecting layer is an electroplated layer plated on the component mounting part; or a conductive adhesive layer arranged on the component mounting part.

9. The circuit board of claim 7,

the thickness of the conductive connecting layer is not more than two thirds of the windowing depth.

10. The circuit board of claim 7, further comprising electronic components;