A portable 4-layer circuit board

Abstract

The utility model provides a portable 4 layer circuit board, including the board body, the board body is by top to bottom sequentially by top layer, middle layer, inner layer, bottom layer is compounded and is formed, a plurality of button module is fixedly connected with the centre of top surface of board body, the pin of button module is welded with the top surface of board body, the surface of board body is opened in the positioning hole, the top surface fixedly connected with the board body of pilot lamp, the connection mode of pilot lamp and board body is the pin insertion, the edge of board body top surface fixedly connected with the chip. The utility model has the advantages of: increasing a few small columnar supports that support column on the surface of circuit board, it is the non - conductive plastic sheet that is pasted in the assembly stage, a small amount of adhesion fixed with the edge of the edge of the board body top surface, silica gel gasket layer pressure and stick on the support column, can significantly reduce the risk that dust, liquid directly contacts the surface of circuit board, improve environmental tolerance, protect the solder joint and element, protect the button module pin, chip pin place from direct physical scratch or impact.

Description

Technical Field

[0001] This utility model relates to the field of circuit board technology, and in particular to a portable 4-layer circuit board. Background Technology

[0002] As portable electronic devices trend towards miniaturization and high integration, four-layer printed circuit boards (PCBs) have become the mainstream design solution due to their excellent signal integrity and power distribution capabilities. However, in harsh environments or high-frequency usage scenarios, these circuit boards face three common technical challenges:

[0003] The increased risk of exposed solder joints and components: Traditional four-layer circuit boards typically employ an exposed layout: surface-mount components (such as chip pins, push-button switch contacts, and LED pads) are directly exposed to the environment. Portable devices are susceptible to the following damage during mobile use: liquid splashes (sweat, rain) cause electrochemical corrosion of solder joints, leading to short circuits or open circuits; metal debris / dust (such as metal particles generated by the friction of pocket keys) bridges precision solder pads; physical scratches cause breakage of peripheral solder joints of QFN and other packaged chips. Therefore, a portable four-layer circuit board is proposed to address the above problems. Utility Model Content

[0004] The purpose of this invention is to at least solve one of the aforementioned technical defects.

[0005] Therefore, one objective of this utility model is to provide a portable 4-layer circuit board to solve the problems mentioned in the background art and overcome the shortcomings of the prior art.

[0006] To achieve the above objectives, one embodiment of the present invention provides a portable layered circuit board, including a board body, which is composed of a top layer, a middle layer, an inner layer and a bottom layer from top to bottom. A plurality of button modules are fixedly connected to the center of the top surface of the board body, and the pins of the button modules are soldered to the top surface of the board body.

[0007] The surface of the board is provided with positioning holes, and an indicator light is fixedly connected to the top surface of the board. The indicator light is connected to the board by pin plugging.

[0008] A chip is fixedly connected to the edge of the top surface of the board, and the pins of the chip are soldered to the top surface of the board.

[0009] Several support pillars are fixedly connected to the edge of the top surface of the board. A gasket layer is fixedly connected to the top of the support pillars. The edge of the gasket layer is bonded to the edge of the top surface of the board. The gasket layer has notches for matching chips and their pins, indicator lights, button modules and their pins. The top surface of the gasket layer is located above the chip pins and button module pins.

[0010] Preferably, in any of the above solutions, the top layer is a conductive layer, and the top layer is made of copper foil.

[0011] The above technical solution results in a circuit board with a compact structure, consisting of a regular rectangular board, which facilitates installation and makes it more portable.

[0012] The top layer of this circuit board is used to place surface-mount components and signal traces. It is one of the main areas for component mounting and soldering. The middle layers, as the base layer of the entire board, provide a stable ground plane. They are typically designed as continuous copper layers, covering most of the area, reducing the inductance of signal loops and lowering electromagnetic interference. When adjacent to power layers, they can form a capacitive effect, stabilizing the power supply.

[0013] The inner layer is the power layer, which distributes the power supply voltage (such as 3.3V, 5V, etc.) and connects to the power supply pins of components on the top and bottom layers. The bottom layer is similar to the top layer.

[0014] Preferably, in any of the above embodiments, the middle layer is a substrate layer and is copper-clad on both sides, and the inner layer is a power layer.

[0015] The special design of this circuit board involves cutting a thinner silicone pad that matches the shape of the circuit board. Openings are made in the pad layer corresponding to the button positions, LED indicator positions, and chip positions. Several tiny columnar supports (support pillars) are added to the circuit board surface; these are non-conductive plastic sheets glued on during assembly. The edges of the pad layer are lightly bonded to the edges of the top surface of the board. The silicone pad is laminated and adhered to the support pillars. This significantly reduces the risk of dust and liquids directly contacting the circuit board surface, improves environmental resistance, protects solder joints and components, and protects button module pins and chip pins from direct physical scratches or impacts.

[0016] Preferably, the top layer, middle layer, inner layer, and bottom layer are heat-pressed together, and the support column is made of plastic.

[0017] Overall Circuit Board Structure: Board Body: The board body is a regular rectangular multilayer printed circuit board (PCB), composed of four layers of materials hot-pressed together from top to bottom, ensuring structural integrity and rigidity. Its regular rectangular shape facilitates installation and fixation inside equipment, while also achieving miniaturization and portability.

[0018] Laminated structure (top layer, middle layer, inner layer, bottom layer): Top layer: Located at the top of the board, preferably a conductive layer made of copper foil. The top layer is the main area for mounting and soldering surface mount components (SMD) and through-hole components. Signal traces are laid on it to connect the signal terminals of components such as button modules, indicator lights, and chips.

[0019] Middle layer: Immediately below the top layer, serving as a substrate layer (e.g., FR4 epoxy glass cloth board) and copper-clad on both sides. Preferably, the side of the middle layer closest to the top layer is designed as a continuous ground plane (GND Plane). The main function of this large-area ground plane is:

[0020] Provides a low-impedance signal return path, reducing signal loop inductance; isolates different signal layers, reducing electromagnetic interference (EMI);

[0021] When adjacent to the top layer above or the inner layer below, distributed capacitance can be formed, which helps to stabilize the power supply.

[0022] Inner layer: Located below the middle layer, it serves as a power layer, used to distribute different power supply voltages (such as 3.3V, 5V, etc.). It connects to the power pins of relevant components on the top and bottom layers through vias, providing a stable, low-noise power supply to the entire board.

[0023] Bottom Layer: Located at the very bottom of the board. Its function is similar to the top layer; it is also a conductive layer (copper foil) used for placing components (primarily for wiring in this embodiment), soldering component leads, and routing signal traces. It can also carry some ground or power copper areas if necessary. Layer Relationship: The top, middle, inner, and bottom layers are bonded together using PCB lamination technology to form a single board structure. Necessary electrical connections between layers are achieved through laser drilling, mechanical drilling, and electroplated metallized vias.

[0024] Core functional component: Button module: Several button modules are mounted near the center of the top surface of the board. Their pins penetrate through the pad holes on the top layer or are directly soldered to the top layer pads (SMD pads) for electrical connection and mechanical fixation. Users trigger signals by pressing the button module.

[0025] Indicator lights: One or more indicator lights are mounted on the top surface of the board (usually near the buttons or in a designated location). Their pins are inserted into through-hole pads on the top layer of the board and fixed by solder connections (pin plug-in), and are used to indicate the device status.

[0026] Chip: At least one processing chip or control chip is fixedly connected to the edge area (such as a corner or long edge) of the top surface of the board. Its pins are usually soldered to precision pads on the top layer (such as QFP or BGA package pads). The chip is the core processor or controller of the board.

[0027] Positioning holes: One or more positioning holes are provided on the surface of the board (through the top and bottom layers). These holes are used for precise positioning by positioning pins when the board is assembled into the terminal equipment or test fixture.

[0028] Innovative protective structure: The most important improvement of this invention lies in the integration of the following structure, which provides effective protection for surface components and sensitive areas:

[0029] Support pillars: Several small, columnar support pillars are fixedly connected at the edge of the top surface of the board (usually avoiding areas with dense wiring and critical components) or utilizing non-functional areas (such as blank spaces near positioning holes). The support pillars are preferably made of high-strength, non-conductive plastic (such as nylon or PPS). Their bases are firmly bonded to designated locations on the top layer of the board (such as insulating areas on the top layer or pre-reserved adhesive pads) using adhesive. The height of the support pillars (typically in the range of 1.0mm-1.5mm) is designed based on protection requirements and component height.

[0030] Spacer layer: A thin spacer layer, precisely matching the outline of the rectangular board but slightly smaller than the board area (or with slightly inward-curving edges), covers the top of the board. The spacer layer is preferably made of flexible, transparent or translucent, weather-resistant silicone. Its edge area is bonded and fixed to the edge area of ​​the top surface of the board (usually the insulating area of ​​the top layer) with a small amount of high-adhesion structural adhesive (such as silicone-specific adhesive).

[0031] Special openings in the gasket layer: To ensure that the gasket layer does not affect the function of the component and precisely covers the parts that need protection, multiple customized notches are made:

[0032] Large square or contour-matched notches are provided corresponding to the chip and its pin locations, ensuring that the entire chip body and its surrounding pads and pins are completely exposed outside the pad layer's coverage area. This prevents impeded heat dissipation or silicone stress from affecting soldering reliability. The top surface of the pad layer is positioned directly above (but not in contact with) the chip pin solder joints near the edge of the notch.

[0033] Support and Protection Relationship: In addition to edge bonding, the lower surface of the gasket layer is also bonded to the top of the support pillars using adhesive (or by utilizing the adhesiveness of the silicone itself). The support pillars support the gasket layer and lift it off the board surface, creating a tiny air gap between the gasket layer and the board (especially above sensitive soldering areas such as button module pin areas and chip pin areas).

[0034] Preferably, in any of the above solutions, the support column is bonded to the top surface of the plate.

[0035] Preferably, in any of the above embodiments, the gasket layer is made of silicone, and the gasket layer is bonded to the top surface of the support column.

[0036] Compared with the prior art, the advantages and beneficial effects of this utility model are as follows:

[0037] This portable 4-layer circuit board features a thinner silicone pad cut to match the board's shape. The pad has openings corresponding to button positions, LED indicator positions, and chip positions. Several tiny columnar supports (support pillars) are added to the board surface; these are non-conductive plastic sheets glued on during assembly. The edges of the pad are lightly bonded to the top edge of the board. The silicone pad is laminated and adhered to the support pillars. This significantly reduces the risk of dust and liquids directly contacting the board surface, improving environmental resistance, protecting solder joints and components, and protecting button module pins and chip pins from direct physical scratches or impacts.

[0038] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0039] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0040] Figure 1 This is a first-view structural schematic diagram of the present invention;

[0041] Figure 2 This is a structural schematic diagram of the present invention from a second perspective;

[0042] Figure 3 This is a schematic diagram of the structure of the plate body of this utility model;

[0043] Figure 4 This is a schematic diagram of the layer structure of the plate body of this utility model.

[0044] In the diagram: 1-Board body, 2-Top layer, 3-Middle layer, 4-Inner layer, 5-Bottom layer, 6-Button module, 7-Positioning hole, 8-Indicator light, 9-Chip, 10-Support column, 11-Pad layer. Detailed Implementation

[0045] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0046] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0047] like Figure 1-4 As shown, this portable 4-layer circuit board includes a board body 1, which is composed of a top layer 2, a middle layer 3, an inner layer 4, and a bottom layer 5 from top to bottom. Several button modules 6 are fixedly connected to the center of the top surface of the board body 1, and the pins of the button modules 6 are soldered to the top surface of the board body 1.

[0048] The surface of the board 1 is provided with positioning holes 7, and an indicator light 8 is fixedly connected to the top surface of the board 1. The indicator light 8 is connected to the board 1 by pin plugging.

[0049] A chip 9 is fixedly connected to the edge of the top surface of board 1, and the pins of chip 9 are soldered to the top surface of board 1.

[0050] Several support pillars 10 are fixedly connected to the edge of the top surface of the board 1. A gasket layer 11 is fixedly connected to the top of the support pillars 10. The edge of the gasket layer 11 is bonded to the edge of the top surface of the board 1. The gasket layer 11 has notches for matching chip 9 and its pins, indicator light 8, button module 6 and its pins. The top surface of the gasket layer 11 is located above the pins of chip 9 and the pins of button module 6.

[0051] Example 1: Top layer 2 is a conductive layer made of copper foil. Middle layer 3 is a substrate layer with copper plating on both sides. Inner layer 4 is a power layer. Top layer 2, middle layer 3, inner layer 4, and bottom layer 5 are bonded together by heat pressing. Support column 10 is made of plastic and is bonded to the top surface of board 1. Spacer layer 11 is made of silicone and is bonded to the top surface of support column 10.

[0052] Example 2: This circuit board has a compact structure, consisting of a regular rectangular board, making it easy to install and more portable. The top layer (2) is used to place surface-mount components and signal traces. It is one of the main areas for component mounting and soldering. The middle layer (3), as the base layer of the entire board, provides a stable ground plane. It is typically designed as a continuous copper layer, covering most of the area, reducing the inductance of signal loops and lowering electromagnetic interference. When adjacent to a power layer, it can form a capacitive effect, stabilizing the power supply.

[0053] Inner layer 4 is the power layer, which distributes power supply voltages (such as 3.3V, 5V, etc.) and connects to the power supply pins of components on the top and bottom layers. Bottom layer 5 is similar to the top layer.

[0054] Overall Circuit Board Structure: Board Body 1: Board Body 1 is a regular rectangular multilayer printed circuit board (PCB), composed of four layers of materials hot-pressed together from top to bottom, ensuring structural integrity and rigidity. Its regular rectangular shape facilitates installation and fixation inside equipment, while also achieving miniaturization and portability.

[0055] Laminated structure (top layer 2, middle layer 3, inner layer 4, bottom layer 5): Top layer 2: Located at the top of board 1, preferably a conductive layer made of copper foil. Top layer 2 is the main mounting and soldering area for surface mount components (SMD) and through-hole components. Signal traces are laid on it to connect the signal terminals of components such as button module 6, indicator light 8, and chip 9.

[0056] Middle layer 3: Immediately below the top layer 2, it serves as a substrate layer (e.g., FR4 epoxy glass cloth board) and is copper-clad on both sides. Preferably, the side of middle layer 3 closest to the top layer 2 is designed as a continuous ground plane (GND Plane). The main function of this large-area ground plane is:

[0057] Provides a low-impedance signal return path, reducing signal loop inductance; isolates different signal layers, reducing electromagnetic interference (EMI);

[0058] When adjacent to the top layer 2 above or the inner layer 4 below, distributed capacitance can be formed, which helps to stabilize the power supply.

[0059] Inner layer 4: Located below the middle layer 3, it serves as a power layer, used to distribute different power supply voltages (such as 3.3V, 5V, etc.). It is connected to the power pins of relevant components on the top layer 2 and the bottom layer 5 through vias, providing a stable, low-noise power supply to the entire board 1.

[0060] Bottom Layer 5: Located at the bottom of board 1. Its function is similar to top layer 2; it is also a conductive layer (copper foil) used for placing components (primarily for wiring in this embodiment), soldering component leads, and routing signal traces. It can also support some ground or power copper areas if necessary. Layer Relationship: Top layer 2, middle layer 3, inner layer 4, and bottom layer 5 are bonded together using PCB lamination technology to form a single board 1 structure. Necessary electrical connections between layers are achieved through laser drilling, mechanical drilling, and electroplated metallized vias.

[0061] Core functional component: Button module 6: Several button modules 6 are mounted near the center area of ​​the top surface of board 1. Their pins penetrate through pad holes on top layer 2 or are directly soldered to pads (SMD pads) on top layer 2, achieving electrical connection and mechanical fixation. The user triggers a signal by pressing the button module 6.

[0062] Indicator 8: One or more indicator lights 8 are mounted on the top surface of board 1 (usually near the button or in a designated location). Their pins are inserted into through-hole pads on the top layer 2 of board 1 and fixed by solder connection (pin plug-in), and are used to indicate the device status.

[0063] Chip 9: At least one processing chip or control chip 9 is fixedly connected to the edge area (such as a corner or long edge) of the top surface of board 1. Its pins are usually soldered to precision pads (such as QFP or BGA package pads) on the top layer 2. Chip 9 is the core processor or controller of board 1.

[0064] Positioning holes 7: One or more positioning holes 7 are provided on the surface of the plate 1 (through the top layer 2 to the bottom layer 5). These holes are used for precise positioning by positioning pins when the plate 1 is assembled into the terminal equipment or test fixture.

[0065] Innovative protective structure: The most important improvement of this invention lies in the integration of the following structure, which provides effective protection for surface components and sensitive areas:

[0066] Support Posts 10: Several small columnar support posts 10 are fixedly connected at the edge of the top surface of the board 1 (usually avoiding areas with dense wiring and critical components) or utilizing non-functional areas (such as blank spaces near positioning holes 7). The support posts 10 are preferably made of high-strength, non-conductive plastic material (such as nylon or PPS). Their bottoms can be firmly bonded to designated locations on the top layer of the board 1 (such as the insulating area on the top layer 2 or pre-reserved adhesive pads) using adhesive. The height of the support posts 10 (typically in the range of 1.0mm-1.5mm) is designed depending on protection requirements and component height.

[0067] Spacer layer 11: A thin spacer layer 11, whose shape precisely matches the outline of the rectangular plate 1 but is slightly smaller than the plate area (or with slightly inward-curving edges), covers the plate 1. The spacer layer 11 is preferably made of flexible, transparent or translucent, weather-resistant silicone material. Its edge area is bonded and fixed to the edge area of ​​the top surface of the plate 1 (usually the insulating area of ​​the top layer 2) with a small amount of high-adhesion structural adhesive (such as silicone-specific adhesive).

[0068] Special openings in gasket layer 11: To ensure that gasket layer 11 does not affect the function of components and precisely covers the parts that need protection, it has multiple customized notches:

[0069] Corresponding to the location of chip 9 and its pins, a large square or contour-matched notch is provided, so that the entire chip 9 body and its surrounding pads and pins are completely exposed outside the coverage area of ​​the pad layer 11, avoiding obstruction of heat dissipation of chip 9 or silicone stress affecting its soldering reliability. The top surface of the pad layer 11 is located just above (but not in contact with) the chip pin soldering point near the edge of the notch of chip 9.

[0070] Support and protection relationship: In addition to edge bonding, the lower surface of the gasket layer 11 is also bonded to the top of the support post 10 by adhesive (or by utilizing the adhesiveness of the silicone itself). The support post 10 supports the gasket layer 11 and lifts it off the surface of the board body 1, forming a small air gap between the gasket layer 11 and the board body 1 (especially above sensitive soldering areas such as the pin area of ​​button module 6 and the pin area of ​​chip 9).

[0071] The working principle of this utility model is as follows:

[0072] Basic Circuit Functions: Board 1 serves as the core carrier, with its four-layer structure (top layer 2 signal trace / component layer, middle layer 3 ground layer, inner layer 4 power layer, and bottom layer 5 signal / component layer) working collaboratively: After external power is input, the inner layer 4 power layer distributes it to each voltage requirement point; the top layer 2 and bottom layer 5 signal traces transmit control and data signals; the middle layer 3 ground layer provides a low-noise reference ground and EMI suppression environment. Button module 6 receives user input and generates signals that are sent to chip 9 for processing via the top layer 2 traces. The status signal output by chip 9 after processing drives indicator light 8 to illuminate, or sends control signals to other interfaces or components on board 1.

[0073] Working principle of integrated protective structure:

[0074] Physical barrier for dust and water protection: The silicone gasket layer 11, through its edge adhesive points and the adhesive points of the support pillar 10, forms a continuous, flexible barrier covering most of the surface of the board 1. It directly blocks most dust particles and liquid splashes (such as water droplets, beverages, etc.) from the external environment from directly contacting the surface of the board 1, and is particularly effective in protecting the exposed solder joints and traces of the button module 6, indicator light 8, chip 9, and other surface-mount components from contamination, oxidation, or short circuit risks. Although not directly covered, the surface of the board 1 beneath the chip 9 is still protected by the gasket layer 11.

[0075] Shock Absorption and Resistance: When the board 1 and its mounted terminal equipment are subjected to minor impacts or drops, the silicone gasket layer 11 absorbs the impact energy using its elasticity and undergoes flexible deformation. On one hand, it effectively buffers the impact force of external shocks on the button module 6, indicator light 8 solder joints, and other surface components located directly below it. On the other hand, when the board 1 vibrates, the damping effect of the gasket layer 11 helps reduce the vibration amplitude of the components and prevents the solder joints from fatigue-induced fracture. The support column 10 strengthens the rigid support of the gasket layer 11, preventing it from collapsing excessively and pressing on the components below.

[0076] Scratch-resistant protection: The silicone layer acts as a "protective film" on the surface, effectively preventing metal tools or other sharp objects from directly scratching fragile components (such as LED lamp bodies and precision solder joints) during installation, maintenance, or daily use.

[0077] Heat dissipation maintenance: The large opening in the pad layer 11 at the chip 9 location ensures unobstructed heat dissipation for the chip 9. The support pillar 10 supports the gap formed by the pad layer 11, which also promotes a small amount of air convection in other areas of the board surface 1, which helps with local heat dissipation.

[0078] Compared with the prior art, the present invention has the following advantages:

[0079] This portable 4-layer circuit board features a thinner silicone pad cut to match the board's shape. The pad layer 11 has openings corresponding to the button positions, LED indicator 8 positions, and chip 9 positions. Several tiny columnar supports, known as support pillars 10, are added to the circuit board surface. These are non-conductive plastic sheets adhered during assembly. The edges of the pad layer 11 are lightly bonded to the edges of the top surface of the board body 1. The silicone pad layer 11 is pressed and adhered to the support pillars 10, significantly reducing the risk of dust and liquids directly contacting the circuit board surface, improving environmental resistance, protecting solder joints and components, and protecting the pins of the button module 6 and chip 9 from direct physical scratches or impacts.

Claims

1. A portable 4-layer wiring board, characterized by comprising: The board (1) is composed of a top layer (2), a middle layer (3), an inner layer (4) and a bottom layer (5) from top to bottom. Several button modules (6) are fixedly connected to the center of the top surface of the board (1). The pins of the button modules (6) are welded to the top surface of the board (1). The surface of the plate (1) is provided with positioning holes (7), and an indicator light (8) is fixedly connected to the top surface of the plate (1). The indicator light (8) is connected to the plate (1) by pin plugging. A chip (9) is fixedly connected to the edge of the top surface of the plate (1), and the pins of the chip (9) are soldered to the top surface of the plate (1). Several support columns (10) are fixedly connected to the edge of the top surface of the plate (1). A gasket layer (11) is fixedly connected to the top of the support column (10). The edge of the gasket layer (11) is bonded to the edge of the top surface of the plate (1). The gasket layer (11) has notches for matching chip (9) and its pins, indicator light (8), button module (6) and its pins. The top surface of the gasket layer (11) is located above the pins of chip (9) and button module (6).

2. The portable 4-layer circuit board of claim 1, wherein: The top layer (2) is specifically a conductive layer, and the top layer (2) is made of copper foil.

3. A portable 4-layer wiring board as claimed in claim 2, characterized by: The middle layer (3) is a substrate layer and is copper-clad on both sides, and the inner layer (4) is a power layer.

4. The portable 4-layer circuit board of claim 3, wherein: The top layer (2), middle layer (3), inner layer (4), and bottom layer (5) are bonded together by hot pressing, and the support column (10) is made of plastic.

5. A portable 4-layer wiring board as claimed in claim 4, wherein: The support column (10) is bonded to the top surface of the plate (1).

6. A portable 4-layer circuit board as claimed in claim 5, characterized in that: The gasket layer (11) is made of silicone and is bonded to the top surface of the support column (10).

Images