A printed circuit board and a method of manufacturing thereof

Abstract

The present disclosure relates to a printed circuit board (PCB) (100) and a method (200) of manufacturing thereof. The PCB 100 comprises a substrate plate (10) defined by a top surface and a bottom surface, a plurality of electronic components (20), a plurality of connectors (30), a plurality of conductive tracks (15), and a protective enclosure. The plurality of electronic components (20) and the plurality of connectors (30) are configured to be mounted on at least one of the top surface or the bottom surface of the substrate plate (10). The electronic components (20) and the connectors (30) are electrically coupled to each other via the conductive tracks (15). The protective enclosure comprises at least one layer of an insulation coating (40) covering the substrate plate (10), the conductive tracks (15), the electronic components (20) and the connectors (30), excluding the terminals 50 of the connectors (30).

Description

[0001] TITLE: A PRINTED CIRCUIT BOARD AND A METHOD OF MANUFACTURING THEREOF

[0002] FIELD

[0003] The present disclosure generally relates to printed circuit boards (PCBs).

[0004] BACKGROUND

[0005] The background information herein below relates to the present disclosure but is not necessarily prior art.

[0006] Presently, engine control units, infotainment systems, and power distribution control units in vehicles are implemented on printed circuit boards (PCBs). The PCBs include various electronic components and connectors. These PCBs are typically housed within protective enclosures made of plastic or metal. The enclosures serve several key functions, such as shielding the electronic components and connectors from mechanical stress, moisture, and dust, as well as providing protection from electrical and thermal damage.

[0007] However, these enclosures negatively impact the overall efficiency and driving range of vehicles, particularly electric vehicles. Additionally, the enclosures take up significant space inside the frame of a vehicle, complicating vehicle design and packaging. Plastic or metal enclosures also increase production costs. Furthermore, additional assembly steps are required for mounting and securing the enclosures, which complicates the manufacturing process.

[0008] There is, therefore, felt a need to develop a printed circuit board and a method for manufacturing thereof, which will alleviate the aforementioned disadvantages.

[0009] OBJECTS

[0010] Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:

[0011] An object of the present disclosure is to provide a printed circuit board that is electrically and thermally insulated from the environment.

[0012] Another object of the present disclosure is to provide a printed circuit board that can be mounted in vehicles without the need for plastic or metal enclosures to house the PCBs. Y et another object of the present disclosure is to provide a printed circuit board that is protected from dust, moisture, and mechanical vibrations.

[0013] Still another object of the present disclosure is to provide a printed circuit board that, when mounted in vehicles, reduces the production cost and production time.

[0014] An object of the present disclosure is to provide a printed circuit board which, when mounted in a vehicle, reduces the overall weight of the vehicle.

[0015] Another object of the present disclosure is to provide a method for manufacturing a printed circuit board.

[0016] Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.

[0017] SUMMARY

[0018] The present disclosure envisages a printed circuit board (PCB). The PCB comprises a substrate plate, a plurality of conductive tracks, a plurality of electronic components, a plurality of connectors, and a protective enclosure.

[0019] The substrate plate comprises a top surface and a bottom surface. The plurality of conductive tracks is defined on the top surface and / or the bottom surface of the substrate plate. The plurality of connectors, which includes terminals, is configured to interface the PCB with external devices. The plurality of electronic components and the plurality of connectors are configured to be mounted on at least one of the top surface or the bottom surface of the substrate plate. The electronic components and the connectors are electrically coupled to each other via the plurality of conductive tracks. The protective enclosure is formed around the PCB to provide electrical and thermal insulation to the PCB. The protective enclosure comprises at least one layer of an insulation coating covering the substrate plate, the conductive tracks, the electronic components, and the connectors, excluding the terminals of the connectors.

[0020] In an embodiment, the insulation coating is formed from an insulation coating solution that includes a polymer base and at least one plasticiser, dissolved in a water-based solvent medium. The polymer base is selected from polyvinyl chloride (PVC), polyamide 11, silicone, plastisol, or combinations thereof, and the plasticizer is selected from glycerol, triacetin, phthalates, or combinations thereof. In an embodiment, the insulation coating has a pre-determined uniform thickness ranging from 0.1 mm to 3 mm.

[0021] The present disclosure further envisages a method for manufacturing a printed circuit board (PCB), wherein the PCB includes a substrate plate, a plurality of conductive tracks, a plurality of electronic components, and a plurality of connectors including terminals. The method comprises the steps of:

[0022] • mounting, the plurality of electronic components and the plurality of connectors on at least one of a top surface or a bottom surface of the substrate plate of the PCB ;

[0023] • coupling the electronic components and the connectors to each other via the plurality of conductive tracks;

[0024] • immersing the PCB, including the substrate plate, the plurality of conductive tracks, the plurality of electronic components, and the connectors, while excluding the terminals of the connectors, into an insulation coating solution;

[0025] • withdrawing the immersed PCB from the insulation coating solution to form at least one layer of an insulation coating over the PCB; and

[0026] • curing the at least one layer of the insulation coating to form a protective enclosure around the PCB, to provide electrical and thermal insulation to the PCB.

[0027] In an embodiment, the insulation coating is formed from an insulation coating solution that includes a polymer base and at least one plasticizer, dissolved in a water-based solvent medium. The polymer base is selected from polyvinyl chloride (PVC), polyamide 11, silicone, plastisol, or combinations thereof, and the plasticizer is selected from glycerol, triacetin, phthalates, or combinations thereof. In an embodiment, the insulation coating as described in the aforementioned method steps is applied on the PCB by a dip-coating technique.

[0028] In an embodiment, the method further includes steps of:

[0029] • measuring a thickness of the insulation coating of the PCB; and

[0030] • repeating the steps of immersing, withdrawing, and curing, until a pre-determined uniform thickness of the insulation coating is achieved on the PCB, wherein the predetermined uniform thickness ranging from 0.1 mm to 3 mm.

[0031] In an embodiment, the method further includes a step of pre-treating the PCB including the substrate plate, the plurality of electronic components, the plurality of connectors, and the plurality of conductive tracks, to remove any contaminants from the PCB before implementing the step of immersing.

[0032] BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING

[0033] A printed circuit board and a method for manufacturing thereof, of the present disclosure will now be described with the help of the accompanying drawing, in which:

[0034] Figure 1 illustrates a printed circuit board before applying a layer of an insulation coating, in accordance with an embodiment of the present disclosure;

[0035] Figure 2 illustrates the printed circuit board with a layer of an insulation coating, in accordance with an embodiment of the present disclosure; and

[0036] Figure 3 illustrates a flow chart of a method for manufacturing a printed circuit board, in accordance with an embodiment of the present disclosure.

[0037] LIST OF REFERENCE NUMERALS USED IN THE DESCRIPTION AND DRAWING:

[0038] 100 - Printed circuit board

[0039] 10 - Substrate plate

[0040] 15 - Conductive tracks

[0041] 20 - Electronic components

[0042] 30 - Connectors

[0043] 40 - Insulation coating

[0044] 50 - Terminals

[0045] 200 - Method for manufacturing a printed circuit board

[0046] 210-250 - Method steps

[0047] DETAILED DESCRIPTION

[0048] Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.

[0049] Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known apparatus structures, and well-known techniques are not described in detail.

[0050] The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms “a”, “an” and “the” may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms “comprises”, “comprising”, “including” and “having” are open-ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0051] When an element is referred to as being “mounted on”, “engaged to”, “connected to” or “coupled to” another element, it may be directly on, engaged, connected, or coupled to the other element. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed elements.

[0052] Figure 1 illustrates a printed circuit board (hereinafter referred to as PCB 100), that is used in vehicles, particularly electric vehicles. The PCB 100 includes a substrate plate 10, a plurality of conductive tracks 15, a plurality of electronic components 20, a plurality of connectors 30, and a protective enclosure. The plurality of conductive tracks 15 is defined on the top surface and / or the bottom surface of the substrate plate 10. The plurality of connectors 30, which includes terminals 50, is configured to interface the PCB 100 with external devices.

[0053] The electronic components 20 are selected from a group of components consisting of resistors, capacitors, inductors, diodes, transistors (such as Bipolar Junction Transistors (BJTs), Field- Effect Transistors (FETs), Junction-Field-Effect Transistors (JFETs), Metal-Oxide- Semiconductor Field-Effect Transistors (MOSFETs), Insulated-Gate Bipolar Transistors (IGBTs) and the like), power transistors, Integrated Circuits (ICs) (such as Microcontrollers, Microprocessors, Operational Amplifiers (Op-Amps), Digital Logic ICs, Analog ICs and the like), crystals and oscillators, switches, sensors, fuses, antennas, heat sinks, MEMS (Micro- Electro-Mechanical Systems) devices, memory chips, and the like. The connectors 30 are selected from a group of connectors consisting of Pin Headers (such as a Single Inline Pin Header (SIP), a Dual Inline Pin Header (DIP)), socket connectors, USB connectors (such as a USB Type-A, USB Type-B, USB Type-C, Micro-USB), Registered Jack (RJ) connectors, HDMI (High-Definition Multimedia Interface) connectors, SATA (Serial AT Attachment) connectors, power connectors, audio connectors, coaxial connectors, Board-to- Board connectors, Memory Card connectors, PCI (Peripheral Component Interconnect) connectors, Radio Frequency (RF) connectors, antenna connectors, and the like.

[0054] The plurality of electronic components 20 and the plurality of connectors 30 are configured to be mounted on at least one of the top surface or the bottom surface of the substrate plate 10. Wherein, the electronic components 20 and the connectors 30 are electrically coupled to each other via the plurality of conductive tracks 15.

[0055] The protective enclosure is formed around the PCB 100 to provide electrical and thermal insulation to the PCB 100. The protective enclosure comprises at least one layer of an insulation coating 40 covering the substrate plate 10, the conductive tracks 15, the electronic components 20, and the connectors 30, excluding the terminals 50 of the connectors 30. Figure 2 illustrates the PCB 100 with the layer of insulation coating 40.

[0056] In an embodiment, the insulation coating 40 is formed from an insulation coating solution. The insulation coating solution includes a polymer base and at least one plasticizer. The polymer base is selected from polyvinyl chloride (PVC), polyamide 11, silicone, plastisol, or combinations thereof, and the plasticizer is selected from glycerol, triacetin, phthalates, or combinations thereof, dissolved in a water-based solvent medium.

[0057] In an embodiment, the insulation coating 40 is applied on the PCB 100 by a dip-coating technique. The dip-coating technique includes the step of immersing the PCB 100 including the substrate plate 10, the plurality of electronic components 20, the plurality of conductive tracks 15, and the plurality of connectors 30, while excluding the terminals 50 of the connectors 30, into the insulation coating solution, so as to form at least one layer of the insulation coating 40 over the PCB 100, and allowing the at least one layer of the insulation coating 40 to solidify, thereby forming a protective enclosure that provides electrical and thermal insulation.

[0058] In an embodiment, the insulation coating 40 has a pre-determined uniform thickness ranging from 0.1 mm to 3 mm. In a preferred embodiment, the insulation coating 40 has a predetermined uniform thickness of 1 mm. Advantageously, the insulation coating 40 on the PCB 100 acts as a protective layer that conforms to the shape of the substrate plate 10, electronic components 20, connectors 30, and the conductive tracks 15, thereby eliminating the need for plastic or metal enclosures for housing the PCB. Thus, the PCB 100, including the insulation coating 40, reduces the overall weight, production cost, and production time of the vehicles. Further, the insulation coating 40 also acts as a mechanical enclosure, protecting the PCB 100 from physical damage, moisture, and environmental dust.

[0059] The present disclosure further envisages a method 200 for manufacturing a printed circuit board (PCB) 100. The PCB 100 includes a substrate plate 10, a plurality of electronic components 20, a plurality of connectors 30, and a plurality of conductive tracks 15.

[0060] The method 200 includes the following steps:

[0061] At step 210: the method 200 includes mounting the plurality of electronic components 20 and the plurality of connectors 30 on at least one of a top surface or a bottom surface of the substrate plate 10 of the PCB 100.

[0062] At step 220: the method 200 includes coupling the electronic components 20 and the connectors 30 to each other via the plurality of conductive tracks 15.

[0063] At step 230: the method 200 includes immersing the PCB 100, including the substrate plate 10, the plurality of conductive tracks 15, the plurality of electronic components 20, and the plurality of connectors 30, while excluding the terminals 50 of the connectors 30, into an insulation coating solution.

[0064] At step 240: the method 200 includes withdrawing the immersed PCB 100 from the insulation coating solution to form at least one layer of an insulation coating 40 over the PCB 100.

[0065] At step 250: the method 200 includes curing 250 the at least one layer of the insulation coating 40 to form a protective enclosure around the PCB 100, to provide electrical and thermal insulation to the PCB 100.

[0066] In an embodiment, the insulation coating 40 as described in the aforementioned method 200 includes a polymer base and at least one plasticizer, where the polymer base is selected from polyvinyl chloride (PVC), polyamide 11, silicone, plastisol, or combinations thereof, and the plasticizer is selected from glycerol, triacetin, phthalates, or combinations thereof, dissolved in a water-based solvent medium. In an embodiment, the insulation coating 40 as described in the aforementioned method 200 is applied on the PCB 100 by a dip-coating technique.

[0067] In an embodiment, the method 200 further include steps of:

[0068] • measuring a thickness of the insulation coating 40 of the PCB 100; and

[0069] • repeating the steps of immersing, withdrawing, and curing, until a pre-determined uniform thickness of the insulation coating 40 is achieved on the PCB 100, wherein the pre-determined uniform thickness ranging from 0. 1 mm to 3 mm.

[0070] In a preferred embodiment, the insulation coating 40 has the pre-determined uniform thickness of 1 mm.

[0071] In an embodiment, the method 200 further includes a step of pre-treating the PCB 100 including the substrate plate 10, the plurality of electronic components 20, the plurality of connectors 30, and the plurality of conductive tracks 15, to remove any contaminants before implementing the step 230 of immersing.

[0072] In an embodiment, the PCB 100 is manufactured in a setup that includes an insulation coating bath, a heating unit, a manual dipping station, and a thermal curing chamber. The insulation coating solution is prepared in a dedicated insulation coating bath using a polymer base and one or more plasticizers. Firstly, the polymer base and the plasticizers are selected. The polymer base includes PVC, polyamide 11, silicone, plastisol, or combinations thereof; and the plasticizers include, but are not limited to, glycerol, triacetin, or phthalates. The selected polymer base and the plasticizers are dissolved in a compatible solvent medium, typically water or a water-additive mixture, to obtain the insulation coating solution. Further, the insulation coating solution is heated and maintained within 60°C to 90°C using the heating unit to promote uniform dispersion and penetration of the selected plasticizer(s) into the polymer base.

[0073] In an embodiment, the viscosity of the insulation coating solution is maintained between 1.2 mPa s and 36,000 mPa s, and the bath temperature is maintained between room temperature and 90°C, preferably 60°C to 90°C. In an embodiment, the heating unit includes a thermostat (and the like) for temperature-controlled heating of the insulation coating solution.

[0074] Once the insulation coating solution is stabilized at the desired viscosity and temperature, the PCB 100, including the substrate plate 10, the plurality of electronic components 20, the plurality of conductive tracks 15 and the plurality of connectors 30, while excluding the terminals 50 of the connectors 30, is manually immersed into the insulation coating bath at the manual dipping station. The immersion is performed under controlled conditions such that the PCB 100 is completely submerged, excluding the terminals 50 of the connectors 30, ensuring uniform coating with the insulation coating solution. After a predetermined immersion period, the PCB 100 is withdrawn so as to form at least one layer of the insulation coating 40 over the entire outer surface of the PCB 100, and allowing excess solution to drain back into the insulation coating bath. The predetermined immersion period depends on the viscosity of the insulation coating solution, wherein highly viscous solutions require longer dipping time compared to low -viscosity solutions, allowing thicker polymers to achieve full penetration.

[0075] The coated PCB 100 is then transferred to the thermal curing chamber, where the coated PCB 100 is subjected to a curing temperature in the range of 160°C to 220°C to solidify the insulation coating. The thermal curing step polymerizes the coating layer and removes residual solvent or moisture, thereby forming a protective enclosure that provides electrical and thermal insulation.

[0076] In an embodiment, during the predetermined immersion period, the insulation coating bath is continuously agitated or stirred to prevent settling of solids and to maintain uniform temperature. In some embodiments, mild pressure or vacuum is applied to assist penetration of the insulation coating solution into narrow gaps between components and substrate surfaces.

[0077] The foregoing description of the embodiments has been provided for purposes of illustration and is not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.

[0078] TECHNICAL ADVANCEMENTS

[0079] The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a printed circuit board and a method for manufacturing thereof, that:

[0080] • is electrically and thermally insulated from the environment;

[0081] • can be mounted in vehicles without the need for plastic or metal enclosures to house the PCBs;

[0082] • is protected from dust, moisture, and mechanical vibrations; • when mounted in vehicles, reduces the production cost and production time; and

[0083] • when mounted in a vehicle reduces the overall weight of the vehicle.

[0084] The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

[0085] The foregoing description of the specific embodiments so fully reveals the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and / or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

[0086] The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

[0087] Any discussion of documents, acts, materials, devices, articles, or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

[0088] The numerical values mentioned for the various physical parameters, dimensions, or quantities are only approximations and it is envisaged that the values higher / lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary. While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

Claims

CLAIMS1 . A printed circuit board (PCB) (100) comprising:• a substrate plate (10) defined by a top surface and a bottom surface;• a plurality of conductive tracks (15) defined on said top surface and / or said bottom surface of said substrate plate (10);• a plurality of electronic components (20);• a plurality of connectors (30) including terminals (50) configured to interface said PCB (100) with external devices, wherein, said plurality of electronic components (20) and said plurality of connectors (30) configured to be mounted on at least one of said top surface or said bottom surface of said substrate plate (10), and said electronic components (20) and said connectors (30) are electrically coupled to each other via said plurality of conductive tracks (15); and• a protective enclosure formed around said PCB (100) to provide electrical and thermal insulation to said PCB (100), said protective enclosure comprising at least one layer of an insulation coating (40) covering said substrate plate (10), said conductive tracks (15), said electronic components (20) and said connectors (30), excluding the terminals (50) of said connectors (30).

2. The PCB (100) as claimed in claim 1 , wherein said insulation coating (40) is formed from an insulation coating solution including a polymer base and at least one plasticizer, said polymer base being selected from polyvinyl chloride (PVC), polyamide 11 , silicone, plastisol, or combinations thereof, and said plasticizer being selected from glycerol, triacetin, phthalates, or combinations thereof, dissolved in a water-based solvent medium.

3. The PCB (100) as claimed in claim 1 , wherein said insulation coating (40) has a pre-determined uniform thickness rangingfrom 0.1 mm to 3 mm.

4. A method (200) for manufacturing a printed circuit board (PCB) (100), said PCB (100) including a substrate plate (10) defined by a top surface and a bottom surface, a plurality of conductive tracks (15), a plurality of electronic components (20), and a plurality of connectors (30) includingterminals (50), said method (200) comprising: mounting (210) said plurality of electronic components (20) and said plurality of connectors (30) on at least one of said top surface or said bottom surface of said substrate plate (10) of said PCB (100);72coupling (220) said electronic components (20) and said connectors (30) to each othervia said plurality of conductive tracks (15);• immersing (230) said PCB (100), including said substrate plate (10), said plurality of conductive tracks (15), said plurality of electronic components (20), and said connectors (30), while excluding the terminals (50) of said connectors (30), into an insulation coating solution;• withdrawing (240) said immersed PCB (100) from the insulation coating solution to form at least one layer of an insulation coating (40) over said PCB (100); and• curing (250) said at least one layer of the insulation coating (40) to form a protective enclosure around said PCB (100), to provide electrical and thermal insulation to said PCB (100).

5. The method (200) as claimed in claim 4, wherein said insulation coating solution comprises a polymer base and at least one plasticizer, said polymer base being selected from polyvinyl chloride (PVC), polyamide 11 , silicone, plastisol, or combinations thereof, and said plasticizer being selected from glycerol, triacetin, phthalates, or combinations thereof, dissolved in a water-based solvent medium.

6. The method (200) as claimed in claim 4, wherein said insulation coating (40) is applied on said PCB (100) by a dip-coatingtechnique.

7. The method (200) as claimed in claim 4, further comprising steps of:• measuring a thickness of said insulation coating (40) of said PCB (100); and• repeating the steps of immersing, withdrawing, and curing until a predetermined thickness of said insulation coating (40) is achieved on said PCB (100), wherein said pre-determined uniform thickness ranging from 0.1 mm to 3 mm.

8. The method (200) as claimed in claim 4 further comprising a step of pre-treating said PCB (100) including said substrate plate (10), said plurality of electronic components (20), said plurality of connectors (30), and said plurality of conductive tracks (15), to remove any contaminants before implementing the step (230) of immersing.

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