Circuit board assembly and electronic device

Abstract

The application discloses a circuit board assembly and an electronic device, and belongs to the technical field of electronic devices. The circuit board assembly comprises a circuit board, a first electronic component, a first shielding structure and a second shielding structure. The first electronic component is arranged on a first surface of the circuit board. The first end of the first shielding structure is connected with the first surface of the circuit board, the second end of the first shielding structure extends in a direction away from the circuit board, and the first shielding structure is arranged around the first electronic component. The second shielding structure is arranged in a stack with the first electronic component, and the second shielding structure is welded or bonded with the second end of the first shielding structure.

Description

Technical Field

[0001] This application belongs to the field of electronic equipment technology, specifically relating to a circuit board assembly and an electronic device. Background Technology

[0002] In electronic devices, metal shielding is typically used to shield the chip's signals to prevent it from radiating outwards and being interfered with by radiation. Current metal shielding devices are usually manufactured through multiple bending processes, resulting in a one-piece, cap-like structure where the top plane and all four sidewalls are seamlessly connected.

[0003] Because the top and sides of the hat-shaped metal shielding component are connected by bending, the metal sheet is prone to springback and residual stress during processing, resulting in irregular warping of the top surface of the finished product. However, as the size of the shielding cover increases, the difficulty of controlling the overall flatness of the shielding cover increases exponentially, making it difficult to guarantee the yield rate. Summary of the Invention

[0004] This application aims to provide a circuit board assembly and electronic device that solves the problem of high failure rate of shielding covers due to difficulty in ensuring the flatness of the shielding cover.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows:

[0006] In a first aspect, embodiments of this application provide a circuit board assembly, the circuit board assembly comprising:

[0007] Circuit board;

[0008] The first electronic component is disposed on the first surface of the circuit board;

[0009] The first shielding structure has a first end connected to the first surface of the circuit board, and a second end of the first shielding structure extending in a direction away from the circuit board. The first shielding structure is arranged around the first electronic component.

[0010] The second shielding structure is stacked with the first electronic component, and the second shielding structure is welded or bonded to the second end of the first shielding structure.

[0011] Secondly, embodiments of this application provide an electronic device that includes the circuit board assembly described in the first aspect.

[0012] In the embodiments of this application, the shielding component adopts a split structure, that is, the shielding component includes a first shielding structure and a second shielding structure with a split design. The second end of the first shielding structure extends vertically away from the circuit board, and the first shielding structure forms a support structure similar to a "fence". The function of the first shielding structure is to raise the height of the shielding layer and reserve sufficient space for the first electronic component. The first shielding structure is arranged around the first electronic component to form a closed or semi-closed frame, which physically isolates the first electronic component in the horizontal direction. The second shielding structure is stacked vertically with the first electronic component, that is, the second shielding structure is located directly above the first electronic component, and the second shielding structure is connected to the second end of the first shielding structure by welding or bonding. By using this split structure, this application simplifies the originally complex three-dimensional bending process into a structure of a vertical frame plus a flat cover plate. Since the first shielding structure and the second shielding structure are split structures, the first shielding structure and the second shielding structure are less likely to generate springback effect and residual stress, thereby avoiding the problem of irregular warping on the top surface of the shielding component. This can greatly reduce the manufacturing difficulty and cost of the shielding component. Even with the background of the gradual increase in the size of the shielding component, the shielding component in this solution can also better control the warping problem.

[0013] Additional aspects and advantages of the 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

[0014] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0015] Figure 1 This is a schematic diagram of a circuit board assembly according to an embodiment of the present invention;

[0016] Figure 2 This is a partial schematic diagram of a circuit board assembly according to an embodiment of the present invention;

[0017] Figure 3 This is a partial schematic diagram of a circuit board assembly according to an embodiment of the present invention;

[0018] Figure 4 This is a schematic diagram of a circuit board assembly according to an embodiment of the present invention.

[0019] Figure label:

[0020] 100 Circuit board assembly, 110 Circuit board, 111 Mounting hole, 112 Ground layer, 113 First surface, 114 Second surface, 115 Metal layer, 121 First electronic component, 122 Second electronic component, 131 First shielding structure, 132 Second shielding structure, 133 First opening, 134 Third shielding structure, 135 Fourth shielding structure, 136 Second opening, 141 Grounding protrusion, 142 Connector, 143 Insertion part, 144 Limiting part, 150 Board-to-board connector. Detailed Implementation

[0021] Embodiments of the present invention will now be described in detail. Examples of these embodiments are illustrated 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 are only used to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0022] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this invention, unless otherwise stated, "a plurality of" means two or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0023] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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 invention based on the specific circumstances.

[0025] The following is combined Figures 1-4 A circuit board assembly and an electronic device according to embodiments of the present invention are described.

[0026] Combination Figure 1 and Figure 2 As shown, in some embodiments of the present invention, a circuit board assembly 100 is provided. The circuit board assembly 100 includes a circuit board 110, a first electronic component 121, a first shielding structure 131, and a second shielding structure 132. The first electronic component 121 is disposed on a first surface 113 of the circuit board 110. A first end of the first shielding structure 131 is connected to the first surface 113 of the circuit board 110, and a second end of the first shielding structure 131 extends in a direction away from the circuit board 110. The first shielding structure 131 is disposed around the first electronic component 121. The second shielding structure 132 is stacked on top of the first electronic component 121, and the second shielding structure 132 is welded or bonded to the second end of the first shielding structure 131.

[0027] In this embodiment, the circuit board 110 can be a printed circuit board, and signal lines, pads, etc. are laid out on the surface of the circuit board 110. The first electronic component 121 refers to the chip, radio frequency module, passive component, etc. that need to be electromagnetically shielded. The first electronic component 121 is prone to becoming a source of interference or a target of interference when it is working, so it needs to be confined inside the metal shield.

[0028] In this embodiment, the shielding component adopts a split structure, namely, the shielding component includes a split-design first shielding structure 131 and a second shielding structure 132. The second end of the first shielding structure 131 extends vertically away from the circuit board 110, forming a support structure similar to a "fence". The function of the first shielding structure 131 is to raise the height of the shielding layer, reserving sufficient space for the first electronic component 121. The first shielding structure 131 is arranged around the first electronic component 121, forming a closed or semi-closed frame, physically isolating the first electronic component 121 in the horizontal direction. The second shielding structure 132 is stacked vertically on top of the first electronic component 121, that is, the second shielding structure 132 is located directly above the first electronic component 121, and the second end of the second shielding structure 132 and the first shielding structure 131 are connected by welding or bonding. By using this split structure, this application simplifies the originally complex three-dimensional bending process into a structure of a vertical frame plus a flat cover plate. Since the first shielding structure 131 and the second shielding structure 132 are split structures, the first shielding structure 131 and the second shielding structure 132 are less likely to generate springback effect and residual stress, thereby avoiding the problem of irregular warping on the top surface of the shielding component. This can greatly reduce the manufacturing difficulty and cost of the shielding component. Even with the background of the gradual increase in the size of the shielding component, the shielding component in this solution can better control the warping problem.

[0029] In one possible embodiment, the first end of the first shielding structure 131 is integrally connected to the metal layer 115 of the circuit board 110, and / or the first shielding structure 131 is formed on the side of the circuit board 110 where the first electronic component 121 is provided by a metal deposition process.

[0030] The first shielding structure 131 is not fixed to the circuit board 110 by welding as an independent prefabricated metal part. Instead, it is grown on the first surface 113 of the circuit board 110 using the bumping process in the semiconductor packaging field, thus forming a first shielding structure 131 with a certain height and extremely high coplanarity. This manufacturing method allows the bottom of the first shielding structure 131 to be combined with the ground network on the surface of the circuit board 110, and the root of the first shielding structure 131 to the surface of the circuit board 110 can achieve a stable connection without intermediate solder. This makes the first shielding structure 131 extremely thin in the thickness direction of the circuit board 110, which helps to reduce the overall thickness of the device.

[0031] In this embodiment, the most problematic connection part is transformed into precisely controllable metal bumps on the circuit board 110, thereby fundamentally solving the soldering problem. In this way, there is no need to set solder feet for the first shielding structure 131, which can reduce the clearance area restriction of the circuit board 110 and provide greater freedom for the layout of electronic components. The use of metal deposition process makes the height and shape consistency of the metal bumps much higher than that of stamping, and the assembly pressure of the shielding component is evenly distributed, avoiding local deformation and improving long-term reliability.

[0032] Of course, in other embodiments, the first shielding structure 131 can also be formed on the circuit board 110 by laser direct forming process, such as embedded metal pillars, conductive paste printing, etc.

[0033] In one possible embodiment, a first shielding structure 131 is disposed around the first electronic component 121, and the second end of the first shielding structure 131 forms a first opening 133. A second shielding structure 132 covers the first opening 133, and the side of the second shielding structure 132 facing the first surface 113 is welded or bonded to the second end of the first shielding structure 131, so that the first shielding structure 131, the second shielding structure 132, and the circuit board 110 form a sealed space for accommodating the first electronic component 121.

[0034] The first shielding structure 131 encloses the first electronic component 121. This enclosure design makes the first shielding structure 131 function as a wall, blocking and reflecting electromagnetic waves from multiple sides. The second shielding structure 132 needs to cover the first opening 133 of the first shielding structure 131, and the side of the second shielding structure 132 facing the first surface 113 needs to be fixedly connected to the second end of the first shielding structure 131 by welding or bonding. Through the above connection, the first shielding structure 131, the second shielding structure 132, and the circuit board 110 together form a sealed space for accommodating the first electronic component 121. On the one hand, the sealed space can effectively suppress the high-frequency noise radiated outward by the first electronic component 121, preventing interference to other sensitive circuits. On the other hand, the sealed space can also block the coupling interference of external electromagnetic fields to the first electronic component 121, thereby significantly improving the signal-to-noise ratio and anti-interference capability of the circuit system. Compared to the traditional single sheet metal bending process of integrated shielding covers, this solution achieves a sealed space through split precision assembly, reducing the dependence on the processing precision of individual components and greatly improving the manufacturability and maintainability of the product.

[0035] In one possible embodiment, the first shielding structure 131 is made of a conductive material, and the first end of the first shielding structure 131 is integrally connected or electrically connected to the ground layer 112 of the circuit board 110.

[0036] The first shielding structure 131 must be made of a conductive material. For example, the first shielding structure 131 is made of high-purity copper (such as electroplated copper or electrolytic copper). The choice of conductive material is a prerequisite for achieving the shielding function, because only a good conductor can reflect and absorb electromagnetic waves, thereby blocking the propagation path of electromagnetic interference. The first end of the first shielding structure 131 is integrally or electrically connected to the grounding layer 112 of the circuit board 110. This integral connection corresponds to the aforementioned bumping process or laser direct forming process, where the metal material of the first shielding structure 131 is physically and chemically integrated with the grounding pad or grounding layer 112 on the surface of the circuit board 110, forming an inseparable continuous conductor. This connection method has the highest structural strength and the lowest contact resistance. Alternatively, the first end of the first shielding structure 131 can also be electrically connected to the circuit board 110 through an intermediate conductor. The above method provides a stable reference ground potential for the shielded first electronic component 121, ensuring the stability of the circuit operation. Furthermore, it effectively guides the induced electromagnetic interference current into the ground plane, avoiding the accumulation and re-radiation of interference, thereby ensuring that the shielding structure itself acts as an equipotential body.

[0037] In one possible embodiment, the circuit board assembly 100 further includes a grounding protrusion 141 and a connector 142. The grounding protrusion 141 is disposed on a first surface 113, with a first end connected to the first surface 113 of the circuit board 110, and a second end extending away from the circuit board 110. The grounding protrusion 141 is made of a conductive material, and its first end is integrally or electrically connected to the ground layer 112 of the circuit board 110. The first surface 113 of the circuit board 110 is provided with a mounting hole 111 for engaging with the connector 142. When the connector 142 is in the mounting state inserted into the mounting hole 111, the connector 142 contacts the grounding protrusion 141 to ground the connector 142.

[0038] The circuit board 110 needs to be fixed to an external rack, mid-frame, or module via connector 142. The grounding protrusion 141 is a conductive protrusion located on the surface of the circuit board 110. The grounding protrusion 141 is directly connected to the ground layer 112 of the circuit board 110. The function of the grounding protrusion 141 is to provide a reliable electrical contact point for screws passing through the mounting hole 111.

[0039] The connector 142 is typically a metal screw or bolt. The connector 142 passes through the mounting hole 111 on the circuit board 110. One end of the connector 142 is fastened to the external structure, and the other end of the connector 142 contacts the grounding protrusion 141.

[0040] The contact between connector 142 and grounding protrusion 141 forms a grounding path. When connector 142 is tightened, it presses against the surface of grounding protrusion 141, ensuring stable contact and thus achieving stable grounding. Since grounding protrusion 141 is located on the surface of circuit board 110, connector 142 maintains good grounding even if circuit board 110 is slightly warped.

[0041] The grounding protrusion 141 is provided on the circuit board 110, so there is no need to provide a protruding structure on the connector 142, thereby reducing the processing difficulty and processing cost of the connector 142.

[0042] In one possible embodiment, the first end of the grounding protrusion 141 is integrally connected to the metal layer 115 of the circuit board 110, and / or the grounding protrusion 141 is disposed on the first surface 113 by a metal deposition process.

[0043] The grounding bump 141 is not fixed to the circuit board 110 by soldering as a separate prefabricated metal part. Instead, it is grown on the first surface 113 of the circuit board 110 using the bumping process in the semiconductor packaging field, thereby forming a grounding bump 141 with a certain height and extremely high coplanarity. This manufacturing method allows the bottom of the grounding bump 141 to be combined with the ground network on the surface of the circuit board 110.

[0044] The use of metal deposition process makes the height and shape consistency of the grounding protrusion 141 much higher than that of the stamping method, and the assembly pressure of the shielding component is evenly distributed, avoiding local deformation and improving long-term reliability.

[0045] Of course, in other embodiments, the grounding protrusion 141 can also be formed on the circuit board 110 by laser direct forming process, such as embedded metal pillar, conductive paste printing, etc.

[0046] In one possible embodiment, the connector 142 has an integrally connected insertion portion 143 and a limiting portion 144. When the connector 142 is in the installed state, the insertion portion 143 is inserted into the mounting hole 111, and the surface of the limiting portion 144 opposite to the first surface 113 abuts against the grounding protrusion 141.

[0047] When the connector 142 is in the installed state, the insertion part 143 is configured to be inserted into the mounting hole 111 of the circuit board 110, and the surface of the limiting part 144 opposite to the first surface 113 (i.e., the top surface of the circuit board 110) can tightly abut against the grounding protrusion 141 preset on the circuit board 110. The dual-coupling structure of the insertion part 143 and the abutment of the limiting part 144 constructs an anti-disengagement locking mechanism, effectively resisting vibration, impact or thermal expansion and contraction stress that the circuit board assembly 100 may be subjected to during assembly, transportation or use, and preventing the first shielding structure 131 from loosening from the surface of the circuit board 110. The tight abutment between the limiting part 144 and the grounding protrusion 141 establishes a low-impedance, large-area electrical contact interface between them, thereby ensuring the grounding continuity and electromagnetic shielding effectiveness of the shielding structure.

[0048] In one possible embodiment, the circuit board assembly 100 further includes a second electronic component 122, a third shielding structure 134, and a fourth shielding structure 135. The second electronic component 122 is disposed on a second surface 114 of the circuit board 110 opposite to the first surface 113. A first end of the third shielding structure 134 is connected to the second surface 114 of the circuit board 110, and a second end of the third shielding structure 134 extends in a direction opposite to the circuit board 110. The third shielding structure 134 is disposed around the second electronic component 122. The fourth shielding structure 135 is stacked on top of the second electronic component 122, and the second end of the fourth shielding structure 135 is soldered or bonded to the third shielding structure 134.

[0049] The first end of the third shielding structure 134 is integrally connected to the metal layer 115 of the circuit board 110, and / or the third shielding structure 134 is formed on the side of the circuit board 110 where the second electronic component 122 is provided by a metal deposition process.

[0050] The third shielding structure 134 is disposed around the second electronic component 122, and the second end of the third shielding structure 134 forms a second opening 136. The fourth shielding structure 135 covers the second opening 136, and the side of the fourth shielding structure 135 facing the circuit board 110 is welded or bonded to the second end of the third shielding structure 134, so that the third shielding structure 134, the fourth shielding structure 135 and the circuit board 110 form a sealed space for accommodating the second electronic component 122.

[0051] The third shielding structure 134 is made of conductive material, and the first end of the third shielding structure 134 is integrally connected or electrically connected to the ground layer 112 of the circuit board 110.

[0052] Electronic components are mounted on both the upper and lower surfaces of the circuit board 110, therefore, shielding structures are required for these components on both surfaces. The third shielding structure 134 raises the height of the shielding layer, providing sufficient space for the second electronic component 122. The third shielding structure 134 surrounds the second electronic component 122, forming a closed or semi-closed frame that physically isolates the second electronic component 122 horizontally. The fourth shielding structure 135 is stacked vertically above the second electronic component 122, meaning it is located directly above the second electronic component 122. The fourth shielding structure 135 is connected to the second end of the third shielding structure 134 by welding or bonding. Because the third and fourth shielding structures 134 and 135 are separate structures, springback effects and residual stress are less likely to occur between them, thus preventing irregular warping of the top surface of the shielding components.

[0053] In one possible embodiment, the first shielding structure 131 and the third shielding structure 134 are formed on the surface of the circuit board 110 by pulse electroplating.

[0054] Pulse electroplating is a key technology choice for performing the metal deposition process in this embodiment. The purpose of pulse electroplating is to overcome the problems of voids, closed tops and insufficient bottom deposition that easily occur when filling metal in high aspect ratio patterns.

[0055] Beneath the area patterned by the thick photoresist, the alternating on and off of the pulsed current controls the migration rate and diffusion behavior of metal ions. This prevents copper-tin ions from accumulating too quickly at the opening when entering the photoresist trench, allowing the metal to grow uniformly from the bottom of the trench upwards, resulting in a dense, defect-free first shielding structure 131 and third shielding structure 134. Taking the first shielding structure 131 as an example, it provides more stable coplanar support during subsequent welding with the second shielding structure 132, ensuring uniform contact pressure between the second shielding structure 132 and the first shielding structure 131 and reducing localized poor connections.

[0056] Compared to DC electroplating, pulse electroplating produces a finer coating with lower internal stress, making the first shielding structure 131 less prone to cracking under thermal cycling and mechanical shock, thereby improving the reliability of long-term operation.

[0057] Combination Figure 1 and Figure 2 As shown, in one possible embodiment, the second shielding structure 132 is a metal cut-out sheet; and / or, the second shielding structure 132 is soldered to the side of the first shielding structure 131 facing away from the circuit board 110.

[0058] The fourth shielding structure 135 is a metal cut-out sheet; and / or, the fourth shielding structure 135 is soldered to the side of the third shielding structure 134 facing away from the circuit board 110.

[0059] Metal cutting discs are thin sheet-like components made from low-magnetic metal materials such as stainless steel and nickel silver through die stamping or laser cutting. Metal cutting discs are easy to process, low in cost, and readily maintain excellent flatness in a planar state. Compared to traditional integral hat-shaped shielding structures that require complex multiple stretching and bending processes, the forming process of metal cutting discs is significantly simplified, and warpage control is much easier.

[0060] The second shielding structure 132 no longer requires welded feet or rolled edges; it only needs to retain straight edges to contact the top surface of the first shielding structure 131. The simplified shape of the second shielding structure 132 reduces mold costs, shortens the processing chain, improves precision, increases reliability, and facilitates standardized production.

[0061] Combination Figure 1 and Figure 2 As shown, in one possible embodiment, a portion of the first shielding structure 131 and the third shielding structure 134 are embedded inside the circuit board 110, and the first shielding structure 131 is electrically connected to the ground layer 112 of the circuit board 110.

[0062] During the metal deposition process, the first shielding structure 131 extends its bottom into the ground layer 112 inside the circuit board 110 via conductive vias or via filling, minimizing the grounding path and impedance of the shielding system. A direct channel with low inductance and low thermal resistance is formed between the ground layer 112 and the first shielding structure 131, which is crucial for the return of high-frequency signals and the conduction of shielding current, effectively reducing resonance in the shielding component. This embedded grounding method reduces solder joints or crimping points, avoiding the problem of increased contact resistance during long-term use. Combined with the high dimensional accuracy of the metal deposition process, the embedded structure exhibits good positional consistency, which is beneficial for maintaining stable shielding performance during mass production.

[0063] Combination Figure 1 , Figure 2 and Figure 3 As shown, in one possible embodiment, there are multiple grounding protrusions 141, and the multiple grounding protrusions 141 are arranged circumferentially along the mounting hole 111. Figure 3 The arrow at point C points to the interval distribution.

[0064] The circumferential distribution of multiple grounding protrusions 141 around the mounting holes 111 increases the contact redundancy between the connector 142 and the grounding protrusions 141. Even if one grounding protrusion 141 experiences poor contact due to foreign objects or minor damage, the remaining grounding protrusions 141 can still maintain grounding continuity. Multi-point contact effectively balances the locking force of the connector 142, preventing pressure concentration at a single point from causing resin cracking or plating peeling on the circuit board 110. The spaced distribution of multiple grounding protrusions 141 also considers assembly tolerances and the distribution of external loads, resulting in a more spatially balanced grounding performance and mechanical stability.

[0065] Combination Figure 1 and Figure 4 As shown, in one possible embodiment, the circuit board assembly 100 further includes a board-to-board connector 150, which is disposed on the surface of the circuit board 110 by a metal deposition process.

[0066] In related technologies, the independent BTB (Board-to-Board connector 150) is replaced by a metal bump array directly formed on the surface of the circuit board 110 through electroplating or other methods. The metal-deposited board-to-board connector 150 can directly conduct to the ground plane during the board fabrication stage, ensuring the shortest possible return path for signals and power. The deposited board-to-board connector 150 not only has a reduced thickness but also eliminates coplanarity issues and cold solder joints that may occur during surface mount technology, improving interconnect reliability.

[0067] Combination Figure 1 and Figure 2 As shown, in one possible embodiment, from the side of the first shielding structure 131 adjacent to the circuit board 110 to the first side away from the circuit board 110, the first shielding structure 131 extends along a first direction ( Figure 2 (The arrow at point A points in the middle) extends, and the angle between the first direction and the circuit board 110 is α, where 80°≤α≤100°.

[0068] The first shielding structure 131 extends towards the side opposite to the circuit board 110. Structurally, the first shielding structure 131 has no outwardly protruding solder feet or supports. The first shielding structure 131 eliminates this type of lateral solder foot structure, retaining only a vertical or near-vertical extension. Eliminating solder feet means a cleaner outline and lower height for the shielding structure, and reduces the likelihood of lateral interference with other structures during assembly. This is particularly important for compact layouts and high-density stacking, helping to reduce the overall thickness of the shielding component and simplifying the manufacturing process, making the shielding component easier to standardize and mass-produce. The third shielding structure 134 follows the same principle.

[0069] In this embodiment, the method of fixing the shielding component to the motherboard is changed. A combination of bumping technology and a flat cover replaces the original cap-shaped shielding structure. Bumps are grown on the circuit board 110 using the bumping process, and then soldered to the cover to fix the shielding component to the motherboard, replacing the conventional soldering method and solving the problem of cold solder joints. Furthermore, the bumping process offers higher dimensional accuracy, smaller thickness, and better flatness, which can minimize the wiring restrictions on the circuit board 110 and increase wiring space, thus better meeting the requirements for miniaturization and weight reduction of the circuit board 110 and the entire device.

[0070] In related technologies, the hat-shaped shielding cover is made by machining. The main difficulties are the machining dimensional accuracy and machining capability. This is reflected in the dimensional accuracy tolerance such as + / -0.10mm and the machining capability such as a rectangle with a diameter ≥5mm or ≥4×6mm. It is impossible to process smaller shielding structures, which cannot meet the development needs of miniaturization and thinning of circuit boards.

[0071] In related technologies, cold solder joints in shielding structures are caused by a mismatch in the warpage between the circuit board and the shielding structure. This embodiment uses a bumping process to form bumps with controllable warpage on the outer layer of the circuit board 110, which are then replaced by a planar second shielding structure 132 to replace the original cap-shaped shielding structure. Since the planar second shielding structure 132 is easier to process and its flatness is easier to control than the cap-shaped shielding structure, the flatness achieved by the bumping process on the surface of the circuit board 110 is also easier to control than the flatness of the circuit board 110 itself.

[0072] The planar second shielding structure 132 only requires cutting a metal sheet to the specified size; that is, only one plane needs to be processed. The brim is made of copper using a bumping electroplating process. The planar second shielding structure 132 is formed by a combination of machining and electroplating processes. The main difficulty of this solution lies in the fact that the patterned electroplating of the circuit board 110 requires a thicker photoresist, high resolution, an additional pattern transfer process, and a pulsed electroplating process.

[0073] The overall design concept of this solution is to replace the two individual units, which are difficult to control for flatness, with two new individual units that are easier to control for flatness. From a design and manufacturing perspective, the solution uses a simpler processing method to replace a more difficult one, thereby reducing the risk of false soldering.

[0074] The circuit board 110 has a layered structure. The first electronic component 121 and the second electronic component 122 are attached to the surface layer of the circuit board 110. The inner layers of the circuit board 110 include signal layers, power layers, and ground plane layers, etc. The signal layers and power layers are not discussed here and will not be described in detail. There is a dielectric layer between each trace layer. Copper-tin bumps are electroplated on the solder pads of the original hat-shaped shielding structure using a bumping process to replace the solder pads and brim of the existing hat-shaped shielding structure, thus replacing the original integral hat-shaped shielding structure with a split shielding component.

[0075] After the bumping is fabricated on the circuit board 110, a planar second shielding structure 132 is soldered onto the bumps to connect to the ground network. When the second shielding structure 132 is fixed by the bumping, it is also connected to the ground plane, thus achieving the shielding function.

[0076] The thickness of the bumping is 0.06mm with a tolerance of + / -0.005mm, which is more than 40% thinner than the brim thickness of common shielding structures. The benefit is a weight reduction of more than 40% in the brim area.

[0077] After the bumping is fabricated on the circuit board 110, the screw without the bump is connected to the bumping during the tightening and pressing process, thereby realizing the connection with the ground network.

[0078] The thickness of the bump is 0.06mm with a tolerance of + / -0.005mm, which is more than 40% thinner than common screws with bumps. The benefit is that the weight of the screw bump portion is reduced by more than 40%.

[0079] The solution in this embodiment changes the way the shielding structure is fixed on the circuit board 110, thereby solving the problem of cold solder joints in the surface mount process. By soldering the planar second shielding structure 132 to the bumping protrusions on the circuit board 110, there is no need to worry about the second shielding structure 132 touching the devices and causing interference.

[0080] The original shielding cover welding area is replaced by copper-tin pillars plated by the Bumping process, so there is no need to make solder feet, saving the manufacturing process and materials of the second shielding structure 132, and also saving the solder pad space of the second shielding structure 132.

[0081] This solution has lower requirements for the warpage of the second shielding structure 132, only requiring control of the warpage of the planar second shielding structure 132, allowing for the fabrication of larger second shielding structures 132. Warpage and flatness control of the circuit board 110 are replaced by control of the coplanarity of the solder balls on the top of the bumping.

[0082] By minimizing the clearance and wiring restrictions of the circuit board 110 to increase wiring space, the requirements for miniaturization and weight reduction of the circuit board 110 and the entire machine can be met to the greatest extent.

[0083] Bumping technology can be used to manufacture BTB male connectors, replacing traditional BTB male connectors. This can reduce the thickness of the BTB connector, thereby reducing the overall thickness of the machine.

[0084] Coplanarity refers to the degree to which multiple surfaces lie on the same plane. Warpage or flatness, which are commonly used, refer to the degree of curvature of a two-dimensional surface. Coplanarity refers to the degree to which multiple surfaces of a multidimensional surface lie on the same plane, ensuring that multiple surfaces coincide. It is typically used in manufacturing and assembly processes to ensure the correct mating and functionality of components.

[0085] Warpage is used to describe the degree of curvature of a plane in space. It is defined as the distance between the two points that are furthest apart in the height direction of the warped plane. It is commonly seen in thin-walled parts due to overall deformation caused by stress or temperature changes.

[0086] The clearance area refers to certain areas of the circuit board 110 where traces and vias are prohibited within a certain distance due to electrical signal, mechanical, or structural requirements. It is an area without traces and vias defined by the design rules of the circuit board 110.

[0087] The connector 142 can be a screw, which is used to fix semi-finished products such as circuit board 110, casing, camera, etc., to the mobile phone mold. The screw with the convex bulge serves both a fixing function and a grounding function.

[0088] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0089] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A circuit board assembly, characterized in that, include: Circuit board; A first electronic component is disposed on the first surface of the circuit board; A first shielding structure, wherein a first end of the first shielding structure is connected to a first surface of the circuit board, a second end of the first shielding structure extends in a direction away from the circuit board, and the first shielding structure is arranged around the first electronic component; The second shielding structure is stacked with the first electronic component, and the second shielding structure is welded or bonded to the second end of the first shielding structure.

2. The circuit board assembly according to claim 1, characterized in that, The first end of the first shielding structure is integrally connected to the metal layer of the circuit board, and / or the first shielding structure is formed on the side of the circuit board where the first electronic component is located by a metal deposition process.

3. The circuit board assembly according to claim 1, characterized in that, The first shielding structure is arranged around the first electronic component, and the second end of the first shielding structure forms a first opening; the second shielding structure covers the first opening, and the side of the second shielding structure facing the first surface is welded or bonded to the second end of the first shielding structure, so that the first shielding structure, the second shielding structure and the circuit board form a sealed space for accommodating the first electronic component.

4. The circuit board assembly according to claim 1, characterized in that, The first shielding structure is made of conductive material, and the first end of the first shielding structure is integrally connected or electrically connected to the ground layer of the circuit board.

5. The circuit board assembly according to any one of claims 1 to 4, characterized in that, The circuit board assembly also includes: A grounding protrusion is disposed on the first surface. The first end of the grounding protrusion is connected to the first surface of the circuit board, and the second end of the grounding protrusion extends in a direction away from the circuit board. The grounding protrusion is made of conductive material, and the first end of the grounding protrusion is integrally connected or electrically connected to the ground layer of the circuit board. The connector has a mounting hole on the first surface of the circuit board for connecting with the connector. When the connector is in the mounting state of being inserted into the mounting hole, the connector contacts the grounding protrusion to ground the connector.

6. The circuit board assembly according to claim 5, characterized in that, The first end of the grounding protrusion is integrally connected to the metal layer of the circuit board, and / or the grounding protrusion is disposed on the first surface by a metal deposition process.

7. The circuit board assembly according to claim 5, characterized in that, The number of grounding protrusions is multiple, and the multiple grounding protrusions are distributed at intervals along the circumference of the mounting hole.

8. The circuit board assembly according to claim 5, characterized in that, The connector has an integrally connected insertion part and a limiting part. When the connector is in the installation state, the insertion part is inserted into the mounting hole, and the surface of the limiting part opposite to the first surface abuts against the grounding protrusion.

9. The circuit board assembly according to claim 1, characterized in that, Also includes: The second electronic component is disposed on the second surface of the circuit board that is opposite to the first surface; A third shielding structure, wherein a first end of the third shielding structure is connected to a second surface of the circuit board, a second end of the third shielding structure extends in a direction away from the circuit board, and the third shielding structure is arranged around the second electronic component; The fourth shielding structure is stacked with the second electronic component, and the fourth shielding structure is welded or bonded to the second end of the third shielding structure; The first end of the third shielding structure is integrally connected to the metal layer of the circuit board, and / or the third shielding structure is formed on the side of the circuit board where the second electronic component is located by a metal deposition process; The third shielding structure is arranged around the second electronic component, and the second end of the third shielding structure forms a second opening; the fourth shielding structure covers the second opening, and the side of the fourth shielding structure facing the circuit board is welded or bonded to the second end of the third shielding structure, so that the third shielding structure, the fourth shielding structure and the circuit board form a sealed space for accommodating the second electronic component; The third shielding structure is made of conductive material, and the first end of the third shielding structure is integrally connected or electrically connected to the ground layer of the circuit board.

10. The circuit board assembly according to claim 1, characterized in that, The circuit board assembly also includes: Board-to-board connectors are disposed on the surface of the circuit board by a metal deposition process.

11. An electronic device, characterized in that, include: The circuit board assembly as described in any one of claims 1 to 10.

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