A circuit board, a double-sided circuit board and a manufacturing process thereof

Abstract

The application discloses a kind of circuit board, double-sided circuit board and its manufacturing process, it is related to circuit board manufacturing technical field;The manufacturing process of the circuit board, comprising: providing a circuit substrate;Utilize conductive paste to form a conductive layer on the circuit substrate;Wherein, the conductive paste is applied on the circuit substrate by non-patterned process;Form a photosensitive layer on the conductive layer, and sequentially pass through exposure, development, etching, film stripping process, obtain conductive circuit.The application utilizes conductive paste to be applied on the circuit substrate by non-patterned process, then pass through exposure, development, etching, film stripping process, obtain conductive circuit, so it is lower to the requirement of equipment, need not expensive patterned forming equipment, and production cost is lower;Secondly, the chemical reagent of etching conductive paste is different from the chemical reagent of traditional etching copper-clad plate, not used to corrode pure metal, only for low cost, and the degree of pollution caused is minimal, suitable for general occasion under production and manufacturing, can satisfy education and maker field population use.

Description

Technical Field

[0001] This invention belongs to the field of circuit board manufacturing technology, and particularly relates to a circuit board, a double-sided circuit board and its manufacturing process. Background Technology

[0002] With the continuous development and application of electronic technology, all kinds of electronic products are constantly appearing in people's daily lives. This has also led to a deeper demand for electronic technology, especially in the fields of education and maker education in recent years, where there is a general demand for low-threshold circuit board manufacturing.

[0003] Current circuit board manufacturing primarily utilizes traditional copper-clad laminates (CCLs) produced through chemical etching. This technology is problematic due to several factors: firstly, it's unsuitable for small-scale, customized circuit board production and incurs high costs; secondly, the chemicals used to etch the copper are highly toxic, making them unsuitable for non-professional handling in general environments, and they also cause significant pollution to water and air. These limitations restrict the technology's application. In addition, existing technologies include additive manufacturing based on conductive pastes, which directly creates circuit patterns using patterned printing processes. However, the expensive equipment for this patterning process further limits its applicability. Summary of the Invention

[0004] In view of this, one object of the present invention is to provide a circuit board manufacturing process to solve the problems of expensive equipment, high cost, high pollution, and limited application in the prior art.

[0005] In some illustrative embodiments, the manufacturing process of the circuit board includes: providing a circuit board substrate; forming a conductive layer on the circuit board substrate using a conductive paste; wherein the conductive paste is applied to the circuit board substrate using a non-patterning process; forming a photosensitive layer on the conductive layer; and sequentially performing exposure, development, etching, and stripping processes to obtain conductive lines.

[0006] In some alternative embodiments, before forming a conductive layer on the circuit substrate using conductive paste, the method further includes: forming a solder resist layer on the circuit substrate to obtain a solder resist substrate; the conductive layer is formed on the solder resist substrate, and after the exposure, development, etching, and stripping processes, conductive lines surrounded by the solder resist layer are obtained.

[0007] In some alternative embodiments, a solder resist layer is formed on the circuit board to obtain a solder resist substrate, specifically including: forming a patterned solder resist layer on the substrate to expose a substrate bare area consistent with the target circuit pattern, thereby forming a circuit groove to accommodate the conductive paste; the conductive layer at least covers the circuit groove.

[0008] In some alternative embodiments, a patterned solder resist layer is formed on the substrate, specifically including: forming a pre-cured solder resist layer on the substrate using a UV-type solder resist film or solder resist agent, and obtaining the patterned solder resist layer through exposure and development processes.

[0009] In some alternative embodiments, the same pattern of solder mask is repeatedly fabricated to increase the depth of the circuit groove.

[0010] In some optional embodiments, the coating of conductive paste to form a conductive layer specifically includes: coating conductive paste on the solder resist layer to form a conductive layer.

[0011] In some optional embodiments, the exposure and development process specifically includes: micro-exposing the photosensitive layer and developing it with a developer to obtain a patterned photosensitive layer covering the conductive lines, and then fully exposing the patterned photosensitive layer to obtain a patterned etch-resistant layer.

[0012] In some optional embodiments, the exposure process specifically includes: exposing the photosensitive layer to a digital mask based on a user-defined electronic pattern.

[0013] Another object of the present invention is to provide a circuit board obtained using the circuit board manufacturing process described in any of the preceding claims.

[0014] Another object of the present invention is to provide a double-sided circuit board that is obtained by repeatedly using the circuit board manufacturing process described in any of the above claims.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] This invention utilizes conductive paste applied to a circuit board through a non-patterning process, followed by exposure, development, etching, and stripping steps to obtain conductive lines. Therefore, it has lower equipment requirements, does not require expensive patterning equipment, and has lower production costs. Secondly, the chemical reagents used to etch the conductive paste are different from those used to etch copper-clad laminates in traditional methods. They are not used to corrode pure metals but are designed for low cost and minimal pollution, making them suitable for general production and suitable for use in education and maker fields. Attached Figure Description

[0017] Figure 1 This is a flow example of the circuit board manufacturing process in an embodiment of the present invention;

[0018] Figure 2 This is a process example of the circuit board manufacturing process in the embodiments of the present invention;

[0019] Figure 3This is an example of the circuit board structure in an embodiment of the present invention;

[0020] Figure 4 This is a second example of the circuit board structure in an embodiment of the present invention;

[0021] Figure 5 This is Example 3 of the circuit board structure in the embodiments of the present invention. Detailed Implementation

[0022] Reference will now be made in detail to various embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. When described in conjunction with these embodiments, it should be understood that the embodiments are not intended to limit the present disclosure to these embodiments. Rather, the present disclosure is intended to cover alternatives, modifications, and equivalents that may be included within the spirit and scope of the present disclosure as defined in the appended claims. Furthermore, numerous specific details are set forth in the following detailed description of the present disclosure to provide a thorough understanding of the present disclosure. However, it should be understood that the present disclosure may be practiced without these specific details. In other instances, known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the present disclosure.

[0023] A flowchart illustrating an example of a circuit board fabrication process according to an embodiment of the present invention is provided. Although specific steps are disclosed in the flowchart, these steps are exemplary. That is, embodiments of the present invention are particularly suitable for performing various other steps and variations thereof described in the flowchart.

[0024] It should be noted that, where there is no conflict, the various technical features in the embodiments of the present invention can be combined with each other.

[0025] This invention discloses a circuit board manufacturing process, specifically, as follows: Figure 1-2 , Figure 1 This is a flow example of the circuit board manufacturing process in an embodiment of the present invention; Figure 2 This is a process example of the circuit board manufacturing process in an embodiment of the present invention; the circuit board manufacturing process includes:

[0026] Step S11: Provide a circuit board 1;

[0027] Step S12: A conductive layer 2 is formed on the circuit board 1 using conductive paste;

[0028] The conductive paste is applied to the circuit board 1 using a non-patterning process;

[0029] Step S13: A photosensitive layer 3 is formed on the conductive layer 2, and then the conductive circuit 4 is obtained by sequentially undergoing exposure, development, etching, and stripping processes.

[0030] This invention utilizes conductive paste applied to a circuit board through a non-patterning process, followed by exposure, development, etching, and stripping steps to obtain conductive lines. Therefore, it has lower equipment requirements, does not require expensive patterning equipment, and has lower production costs. Secondly, the chemical reagents used to etch the conductive paste are different from those used to etch copper-clad laminates in traditional methods. They are not used to corrode pure metals but are designed for low cost and minimal pollution, making them suitable for general production and suitable for use in education and maker fields.

[0031] Specifically, the conductive paste in this embodiment of the invention uses a polymer as the carrier medium, meaning the conductive paste at least includes a polymer carrier medium and conductive particles. The polymer carrier medium can be one or a mixture of at least two of the following: polyester resin, polyurethane resin, epoxy resin, acrylic resin, phenolic resin, alkyd resin, silicone resin, vinyl chloride resin, or polyimide resin. Those skilled in the art should understand that, in addition to the aforementioned resin materials, other polymer carrier media with the same or similar properties can be selected in this embodiment of the invention. The conductive particles can include metallic conductive particles and / or non-metallic conductive particles. The metallic conductive particles are not limited to one or a mixture of at least two of the following metallic elements / alloys: gold, silver, nickel, copper, zinc, tin, indium, bismuth, gallium, etc. The non-metallic conductive particles are not limited to one or a mixture of at least two of the following: conductive carbon black, graphene, carbon nanotubes, etc.

[0032] For example, the conductive paste in the embodiments of the present invention may be conductive silver paste, conductive carbon paste, conductive copper paste, or liquid metal conductive paste.

[0033] Specifically, in this embodiment of the invention, liquid metal refers to a low-melting-point metal with a melting point below 300°C; furthermore, the liquid metal can be a low-melting-point metal that is liquid at room temperature, such as elemental gallium or gallium-based alloys, such as gallium-indium alloys, gallium-tin alloys, gallium-indium-tin alloys, gallium-indium-zinc alloys, etc.

[0034] Preferably, the conductive paste in this embodiment of the invention is a conductive paste doped with liquid metal, which at least includes room temperature liquid metal, conductive particles (such as silver, copper, gold, nickel, zinc, etc.), and a polymer carrier medium. Because the conductive paste contains liquid metal, after the polymer carrier medium evaporates and solidifies into a film, the liquid metal can bridge adjacent conductive particles, thereby improving the conductivity of the conductive circuit. On the other hand, due to the fluidity of the room temperature liquid metal, the flexibility and tensile strength of the conductive circuit can be improved, thus giving the circuit board flexible and stretchable properties. Furthermore, the fluid liquid metal can self-fill and repair defects caused by bending or stretching in the conductive circuit, achieving a self-healing function.

[0035] The mass ratio of liquid metal to conductive particles in the conductive paste is 1:20 to 1:5. This is mainly because when the content of liquid metal is too low, the liquid metal does not provide ideal flexibility, stretching, and self-healing properties for the circuit board. When the content of liquid metal is too high, the presence of liquid metal and its oxides results in a large sheet resistance of the conductive paste and poor electrical performance.

[0036] The non-patterning process for applying conductive paste in this embodiment of the invention refers to a process where the target circuit pattern cannot be obtained in one step, such as scraping, spin coating, atomized spraying, dipping, brushing, etc. Those skilled in the art should understand that, in addition to the above-mentioned processes, the non-patterning process in this embodiment of the invention can also be applied to the application of conductive paste with unintended patterns using methods such as screen printing and pad printing. Compared to directly using screen printing or pad printing to create the target circuit pattern, a general-purpose screen (i.e., a screen with at least covering the target conductive pattern) can be used to create unintended patterns, eliminating the need for customized screens, thus reducing costs and improving production efficiency.

[0037] Preferably, in the embodiments of the present invention, the non-patterning process is a scraping process. Compared with other processes, the scraping process is easy to operate, has good quality, and has very low requirements for equipment. It can even be achieved manually.

[0038] In this embodiment of the invention, the photosensitive layer 3 is not limited to the formation of a UV-type etch-protective dry film or a UV-type etch-resistant agent, but is used to achieve an etch-resistant layer 32 covering the conductive lines by UV light irradiation.

[0039] Specifically, the exposure, development, etching, and stripping processes in the embodiments of the present invention specifically include:

[0040] After forming a photosensitive layer 3 covering the conductive layer 2 on the conductive layer, UV light is used to provide patterned illumination consistent with the target circuit pattern, thereby forming an etch resist layer 32 covering the conductive lines 4 on the conductive layer 2. Then, the undenatured photosensitive layer 31 is removed using a developer, and the conductive layer 2 exposed outside the etch resist layer 32 is etched using an etchant to obtain the conductive lines 4 covered by the etch resist layer 32. Finally, the etch resist layer 32 is removed using a stripping agent to obtain the conductive lines 4 consistent with the target circuit pattern.

[0041] The patterned illumination consistent with the target circuit pattern using UV light can be achieved through traditional film masks or equivalent solutions. Preferably, this invention can achieve patterned illumination consistent with the target circuit pattern using a digital mask. The digital mask in this embodiment is an electronic display panel, commonly used to construct electronic displays. This electronic display panel includes a plurality of pixels that can form light-shielding or light-transmitting points. According to the electronic pattern set by the user, the combination of light-shielding pixels can form a corresponding light-shielding pattern, and the combination of light-transmitting pixels can form a corresponding light-transmitting pattern, thereby achieving the same technical effect as a film mask. The higher the pixel resolution of the digital mask, the higher the mask precision it achieves; this will not be elaborated further here.

[0042] This embodiment utilizes a digital photomask to achieve optical patterning, which saves on the high cost of traditional film masks and their manufacturing costs compared to traditional film masks. On the other hand, it can directly form electronic patterns set by users, making mask forming efficient and able to meet the needs of users to make personalized circuit boards, which is very suitable for the board making needs of education or maker groups.

[0043] The applicant discovered that, since the digital photomask is itself an electronic display panel, its light transmittance is somewhat inferior to that of a traditional film mask due to the influence of its thickness and material. Therefore, when UV light passes through the digital photomask, slight diffuse reflection occurs. During the process of the photosensitive layer reaching full exposure and transforming into the etch resist layer, the photosensitive layer around the target area is also prone to a certain degree of denaturation, resulting in incomplete development during the subsequent development process, causing the area around the target etch resist layer to become blurred.

[0044] In response, the applicant proposed the following technical means to solve the above problems, specifically:

[0045] After forming a photosensitive layer covering the conductive layer on top of the conductive layer, the photosensitive layer is first micro-exposed and then developed using a developer to obtain a patterned photosensitive layer that covers the conductive lines. The patterned photosensitive layer is then fully exposed to obtain a patterned etch-resistant layer.

[0046] In this embodiment of the invention, micro-exposure refers to the degree to which the UV energy is insufficient to completely transform the photosensitive layer of the target area into an anti-etching layer. The area around the target area of ​​the photosensitive layer is only deformed due to a small amount of energy emitted from the aforementioned defects. At this time, a low concentration of developer can be used to remove the non-target area of ​​the photosensitive layer. Then, the target area of ​​the photosensitive layer is fully exposed to completely deform it, thereby achieving the effect of an anti-etching layer that prevents the conductive lines from being etched.

[0047] For example, in this embodiment of the invention, the photosensitive layer is a commercially available UV-cured etch-protective dry film, and a UV light source is used to provide curing energy. The power of the UV light source is set to 150W. During the micro-exposure operation, the photosensitive layer is exposed based on the above-mentioned materials and equipment for 135s. The photosensitive layer after micro-exposure is then developed using a developer (such as 1WT% Na2CO3, 1.1WT% K2CO3, 1.1WT% Na2CO3, etc.) to obtain a photosensitive layer that only covers the conductive lines. Then, the photosensitive layer is fully exposed using the same curing equipment for 240s to obtain an etch-resistant layer that resists the corrosion of the mixture of etchant (such as DBE solvent) and the conductive layer (such as silver paste curing). Then, during the stripping process, a stripping agent (such as 3.0WT% NaOH, 3.0WT% KOH, etc.) is used to strip the etch-resistant layer.

[0048] Those skilled in the art should understand that the materials, equipment, and parameters in the above examples are preferred embodiments of the present invention and do not limit the actual scope of protection of the present invention. They are only used to facilitate a quick understanding of the technical concept of the present invention by those skilled in the art. In addition to the specific materials, equipment, and parameters given in the above examples, other variations can be used to achieve the same result.

[0049] Specifically:

[0050] In this embodiment of the invention, micro-exposure refers to the situation where the target area of ​​the photosensitive layer does not completely transform into an etch-resistant protective layer after micro-exposure. That is, the photosensitive layer after exposure is still subject to corrosion and damage by the etching solution, but it will not be corroded by the developer; the developer can only corrode the unexposed photosensitive layer. Those skilled in the art can achieve this effect by adjusting equipment, materials, parameters, and other methods.

[0051] In this embodiment of the invention, full exposure means that the target area of ​​the photosensitive layer is completely transformed into an anti-etching protective layer after full exposure, that is, the photosensitive layer after exposure treatment will not be corroded or damaged by the etching solution.

[0052] Those skilled in the art should understand that the above-described exposure and development are applicable not only to circuit patterning based on digital photomasks, but also to circuit patterning based on traditional film masks, as well as other patterning processes based on photolithography.

[0053] The etching principle of the etching solution used to etch the conductive layer formed by the conductive paste in this embodiment of the invention is to dissolve the film-forming material in the conductive layer, thereby freeing the conductive particles from the binding of the film-forming material and removing them. Compared with the etching solution used in traditional copper foil etching, it does not generate a large amount of toxic waste gas or waste liquid, and its waste liquid does not contain heavy metal pollutants, reducing the difficulty of waste liquid treatment and also facilitating the recycling and reuse of conductive particles in the waste liquid.

[0054] In this embodiment of the invention, the etching solution is selected based on the properties of the polymer carrier medium in the conductive paste, and a corresponding etching solution that can dissolve the film-forming product of the polymer carrier medium is selected.

[0055] Preferably, the etching solution in the embodiments of the present invention is DBE solvent, also known as a mixture of second-order acid esters or dimethyl nylonate, which has the advantages of being non-toxic, having a high boiling point, being biodegradable, and being environmentally friendly and harmless, making it suitable for use in general scenarios and by people with lower levels of expertise.

[0056] The applicant found that in traditional industrial sectors, conductive pastes (such as conductive silver paste) are mainly used in busbars of thin-film solar panels, transparent displays, and flexible printed circuit boards (FPCs). Busbars and transparent displays have relatively low requirements for component soldering. In transparent displays, LED chip soldering primarily relies on high-precision placement machines and conductive adhesives, with almost no need for solder mask on the circuit board. Flexible printed circuit boards (FPCs) mainly avoid soldering problems by attaching a windowed cover film to expose the electrodes and pads. However, for the general public in fields such as education and maker spaces, the operational skills are lower, soldering problems are more likely, and there is a need for repeated soldering, debugging, and repair. Therefore, the circuit board needs to have solder mask functionality. However, the windowing and alignment processes in the FPC cover film manufacturing process are quite complex, requiring specialized industrial equipment, making it unsuitable for low-cost, low-barrier-to-entry users.

[0057] For traditional PCB circuit boards, the solder mask layer is generally formed by applying solder mask to the conductive lines after the circuit is formed by screen printing. After pre-curing, the solder mask layer is exposed and developed to obtain a solder mask layer that exposes the electrodes and pads. However, the conductive layer formed by the solder mask and conductive paste will produce a small amount of corrosion, which can easily affect the electrical performance of the conductive lines.

[0058] In this regard, such as Figure 3-4 As shown in the embodiment of the present invention, before forming a conductive layer on the circuit substrate using conductive paste, the method may further include: forming a solder resist layer 5 on the circuit substrate 1 to obtain a solder resist substrate; the conductive layer 2 is formed on the solder resist substrate, and after the exposure, development, etching and stripping processes, a conductive line 4 surrounded by the solder resist layer 5 is obtained.

[0059] In this embodiment, a solder resist layer is pre-fabricated on the circuit board. After the solder resist layer is fully cured, the chemical reaction between it and the conductive paste can be avoided, thereby ensuring the electrical performance of the conductive circuit and enabling the circuit board to achieve the function of solder resist.

[0060] The solder resist layer in the embodiments of the present invention can be formed by solder resist dry film or solder resist agent, which will not be described in detail here.

[0061] Although conductive pastes contain polymeric carrier media (such as resin components that can act as adhesives), allowing them to adhere to the solder mask layer with a certain degree of adhesion strength, for flexible circuit boards, the conductive lines formed by the conductive paste can still peel off or detach as the solder mask material ages and experiences fatigue bending. This can negatively impact the stability and lifespan of the circuit board. If long-term stability and lifespan are not a concern, the conductive paste can be directly applied to the solder mask layer to obtain the conductive lines.

[0062] However, to address the aforementioned problems, this embodiment of the invention proposes an improvement measure: a patterned solder resist layer 5 is formed on the substrate to expose a bare substrate area A that matches the target circuit pattern. The subsequently applied conductive paste at least covers the bare substrate area A, and the subsequent photosensitive layer 3 also at least covers the bare substrate area A. Then, based on the pattern and position of the bare substrate area A, exposure, development, etching, and stripping processes are performed to obtain conductive lines 4 surrounded by the solder resist layer 5. The conductive lines 4 are directly attached to the circuit board 1, thereby improving the stability and lifespan of the circuit board.

[0063] Preferably, forming a patterned solder resist layer on the substrate may include: forming a pre-cured solder resist layer on the substrate using a UV-type solder resist film or solder resist agent, and obtaining the patterned solder resist layer through exposure and development processes. Alternatively, without considering equipment costs, the solder resist layer can also be fabricated using patterning processes such as screen printing, and the solder resist layer can also be a thermosetting solder resist dry film or solder resist agent. The exposure and development based on the digital photomask can also be performed in accordance with the methods described above for the exposure and development of the improved photosensitive layer.

[0064] Furthermore, by forming a patterned solder resist layer 5 on the circuit board and exposing a bare substrate area A that matches the target circuit pattern, circuit grooves to accommodate the conductive paste will inevitably be formed in the solder resist layer 5. Therefore, by controlling the thickness of the solder resist layer 5, the thickness of the conductive line 4 can be controlled, thereby meeting the requirements of the conductive line 4 such as high current. The conductive layer 2 at least completely covers the circuit grooves.

[0065] Preferably, such as Figure 5 As shown, in this embodiment of the invention, the depth of the circuit groove can be increased by repeatedly fabricating solder mask layers with the same pattern (such as the first solder mask layer 51 and the second solder mask layer 52), and the purpose of achieving the conductive line 4 with the thickness required by the user can be achieved.

[0066] Another object of the present invention is to provide a circuit board that can be obtained using the circuit board manufacturing process described in any of the above embodiments.

[0067] Another object of the present invention is to provide a double-sided circuit board that can be obtained by repeatedly using the circuit board manufacturing process described in any of the above claims, that is, firstly, a single-sided circuit is made on one side of the circuit board, and then a single-sided circuit is made on the other side of the circuit board to obtain a double-sided circuit board.

[0068] In a typical double-sided circuit board, the circuits on both sides of the circuit board need to be connected. This may also include: opening vias on the circuit board and performing via metallization to achieve the purpose of connecting the double-sided circuit board.

[0069] Preferably, in this embodiment of the invention, vias are formed at target locations on the circuit board before the conductive paste is applied, and the vias are metallized integrally during the application of the conductive paste. Specifically, the vias can be formed directly on the circuit board or on the solder mask substrate after the solder mask layer has been formed. The via forming process can employ existing technologies such as drilling or laser engraving, which will not be elaborated here.

[0070] The circuit board in the embodiments of the present invention can be selected from conventional circuit substrates in the prior art, and is not limited to traditional PCB substrates, FPC substrates, as well as glass substrates, paper substrates, fabric substrates, polyimide substrates, PE substrates, PET substrates, PU substrates, plastics, wood, etc.

[0071] To facilitate a quick understanding of this solution by those skilled in the art, a preferred embodiment of the circuit board manufacturing process in this invention is provided below:

[0072] Step S21: Provide a circuit board;

[0073] Step S22: Apply a layer of UV-type solder resist dry film to the circuit board using a laminating machine;

[0074] Step S23: Based on the digital photomask, the UV-type solder resist dry film is patterned by exposure and development using the first electronic pattern set by the user to obtain a patterned solder resist layer.

[0075] In this process, the user-defined first electronic pattern is the same as the target circuit pattern, that is, the light-blocking pattern of the digital mask is the same as the target circuit pattern, and its light-transmitting pattern is opposite to the target circuit pattern, thereby enabling the solder resist dry film on the periphery of the target circuit area on the circuit board to receive light-curing energy and be converted and cured.

[0076] Step S24: Apply conductive paste using a scraping device to cover the exposed area of ​​the substrate outside the solder resist layer, and perform a heat curing treatment to obtain a conductive layer covering the exposed area of ​​the substrate.

[0077] Step S25: Use a laminating machine to attach the photosensitive dry film onto the conductive layer;

[0078] Step S26: Based on the digital mask, the photosensitive dry film is patterned by exposure and development using the second electronic pattern set by the user to obtain a patterned anti-etching layer;

[0079] The second electronic pattern set by the user is the opposite of the first electronic pattern. That is, the light-blocking pattern of the digital mask is the opposite of the target circuit pattern, while its light-transmitting pattern is the same as the target circuit pattern, thereby enabling the photosensitive dry film in the target circuit area to receive light-curing energy and be converted and cured.

[0080] Step S27: Use an etching solution to etch the conductive layer exposed outside the etch-resistant layer to obtain the etch-resistant layer.

[0081] Step S28: Use a stripping agent to strip the anti-etched layer, thereby obtaining conductive lines on the circuit board surrounded by a solder resist layer.

[0082] The equipment used in the above embodiments consists only of a coating machine, a UV light processing machine based on a digital mask, and a laminating machine. The above equipment has a simple structure, low cost, low operation requirements, and is all small desktop equipment, making it especially suitable for people in the low-threshold education and maker fields.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A circuit board manufacturing process, characterized in that, include: Provide a circuit board; A conductive layer is formed on the circuit board using a conductive paste. The conductive paste is applied to the circuit board using a non-patterning process; A photosensitive layer is formed on the conductive layer, and the conductive circuit is obtained by sequentially undergoing exposure, development, etching, and stripping processes. The exposure and development processes specifically include: The target area of ​​the photosensitive layer is micro-exposed to make the photosensitive layer in the target area resistant to developer but not resistant to etchant. The photosensitive layer in the non-target area is developed using developer to obtain a patterned photosensitive layer that covers the conductive lines. Then, the photosensitive layer is fully exposed to transform it into an etch-resistant layer that is resistant to etchant.

2. The circuit board manufacturing process according to claim 1, characterized in that, Before forming a conductive layer on the circuit board using a conductive paste, the method further includes: A solder resist layer is formed on the circuit board to obtain a solder resist substrate. The conductive layer is formed on the solder resist substrate. After the exposure, development, etching and stripping processes, conductive lines surrounded by the solder resist layer are obtained.

3. The circuit board manufacturing process according to claim 1, characterized in that, A solder resist layer is formed on the circuit board to obtain a solder resist substrate, specifically including: A patterned solder resist layer is formed on the substrate, exposing a bare area of ​​the substrate that matches the target circuit pattern, thereby forming a circuit groove to accommodate the conductive paste. The conductive layer at least completely covers the circuit groove.

4. The circuit board manufacturing process according to claim 3, characterized in that, A patterned solder resist layer is formed on the substrate, specifically including: A pre-cured solder resist layer is formed on the substrate using a UV-type solder resist film or solder resist agent, and the patterned solder resist layer is obtained through exposure and development processes.

5. The circuit board manufacturing process according to claim 3, characterized in that, Repeat the fabrication of solder resist layers with the same pattern to increase the depth of the circuit grooves.

6. The circuit board manufacturing process according to claim 1, characterized in that, The exposure process specifically includes: The photosensitive layer is exposed using a digital mask based on a user-defined electronic pattern.

7. A circuit board, characterized in that, Obtained using the manufacturing process of the circuit board according to any one of claims 1-6.

8. A double-sided circuit board, characterized in that, Obtained by repeatedly using the manufacturing process of the circuit board according to any one of claims 1-6.

Images