Circuit board assembly and electronic device
By using high-temperature molten metal wires to connect mating pads and functional pads in circuit board components and electronics, the impact of flux residue on optical devices is solved, and signal integrity and assembly accuracy are improved.
Patent Information
- Application Number
- CN202411375002.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2024-12-27
AI Technical Summary
In the splicing design of chips and PCB boards in flexible circuit boards, flux residues will affect the brightness of the optical product, resulting in the failure of the optical device.
The circuit board components and electronic components are designed, in which the mating pads on the circuit board and the functional pads on the chip are connected through high-temperature molten metal wires to form metal wire connections, avoiding the use of solder paste and flux, thereby in the assembly process No flux residue is produced in it.
Effectively avoid the impact of flux residue on the optical device, improve signal integrity and assembly accuracy, and reduce the risk of optical device failure.
Smart Images
Figure CN119212212A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of circuit board components, and in particular to a circuit board component and an electronic device. Background Art
[0002] The splicing design of chips and PCB boards in flexible circuit boards is generally done through solder paste welding process. After the assembly is completed, there is a problem that the flux remains on the surface of the optical product, which will affect the brightness of the optical product. Summary of the invention
[0003] The main purpose of the present invention is to provide a circuit board assembly and an electronic device, aiming to solve the problem of optical device failure caused by flux residue.
[0004] To achieve the above object, the circuit board assembly proposed by the present invention includes:
[0005] A circuit board having a first side and a second side opposite to each other, wherein the first side of the circuit board has at least one mounting area, and the circuit board is provided with a plurality of mating pads at the periphery of the mounting area; and
[0006] The chip is arranged in the installation area, and a plurality of functional pads are arranged on the periphery of the end surface of the chip facing away from the circuit board, and each of the functional pads is connected to each of the matching pads through a metal wire.
[0007] In one embodiment, the installation area has a plurality of side edges, and the plurality of side edges include two first side edges arranged opposite to each other in a first direction, and two second side edges arranged opposite to each other in a second direction;
[0008] The plurality of mating pads are disposed corresponding to at least one side of the mounting area.
[0009] In one embodiment, the chip has two first side edges opposite to each other in a first direction, at least one of the first side edges is provided with a plurality of the functional pads to form a functional pad group, and the plurality of functional pads in the functional pad group are first functional pads;
[0010] The multiple mating pads correspond to at least one mating pad group formed by the functional pad group, the multiple mating pads in the mating pad group are first mating pads, the multiple first mating pads are arranged in one-to-one correspondence with the multiple first functional pads, and at least part of the multiple first mating pads are arranged along the corresponding first side.
[0011] In one embodiment, in at least one of the mating pad groups, other portions of the plurality of the first mating pads are arranged corresponding to at least one of the second sides.
[0012] In one embodiment, two functional pad groups are provided, and are correspondingly arranged at two first side edges;
[0013] Correspondingly, two matching pad groups are provided.
[0014] In one embodiment, in at least one of the mating pad groups, a plurality of the first mating pads corresponding to the first side are distributed in at least two rows in the first direction.
[0015] In one embodiment, the plurality of mating pads include two second mating pads having the same electrical properties, and the two second mating pads are arranged in a bonded manner.
[0016] In one embodiment, the plurality of mating pads include two third mating pads having electrical properties of positive and negative electrodes of differential signals, and the two third mating pads are arranged corresponding to the same side and are arranged side by side along the length direction of the corresponding side.
[0017] In one embodiment, the projection of the metal wire on the circuit board is inclined to the vertical line of the corresponding side of the chip, and the angle of inclination is α, wherein: α≤ 45° 。
[0018] In one embodiment, the size of the mating pad in the first direction is L1, and the size of the mating pad in the second direction is W1, wherein:
[0019] L1 ≥ 2*w1; and / or,
[0020] W1≥match the pad molding design tolerance + 0.05mm.
[0021] In one embodiment, the circuit board is provided with at least two positioning pads at the periphery of the mounting area, and the two positioning pads are arranged on two opposite sides of the chip along the direction where the diagonal line of the chip is located.
[0022] In one embodiment, each of the positioning pads includes two pad segments arranged at an angle, and the two pad segment pairs correspond to two adjacent sides of the chip respectively.
[0023] In one embodiment, the dimension of the positioning pad along the second direction is L2, L2 ≥ 0.2 mm; and / or,
[0024] The dimension of the positioning pad along the first direction is W2, wherein W2≥circuit board dimension design tolerance+0.05 mm.
[0025] In one embodiment, the spacing between the positioning pad and the adjacent mating pad is D1, wherein D1≥chip size design tolerance+positioning pad molding design tolerance+chip mounting design tolerance+0.05 mm.
[0026] In one embodiment, the distance between the mating pad and the chip is D2, wherein D2=chip size design tolerance+mating pad molding design tolerance+chip mounting design tolerance+0.05 mm.
[0027] In one embodiment, a plurality of capacitance and resistance components are disposed on the second side of the circuit board.
[0028] In one embodiment, a reinforcing plate is provided on the second side of the circuit board, and a plurality of avoidance holes are penetrated on the reinforcing plate;
[0029] The plurality of capacitance components are located in the plurality of avoidance holes.
[0030] In one embodiment, the distance between the capacitance component and the corresponding avoidance hole is D3, wherein D3≥reinforcement plate installation design tolerance+chip installation design tolerance+0.05mm.
[0031] The present invention further provides an electronic device, characterized in that it comprises the above-mentioned circuit board assembly.
[0032] In the technical solution of the present invention, the matching pads on the circuit board are connected to the functional pads on the chip through metal wires. The metal wires are connected to the pads by first melting the ends of the metal wires at high temperature and then connecting them to the pads made of metal materials to complete the splicing. The entire assembly process does not involve solder paste and flux, and can also ensure the connection state of the chip and the circuit printed on the circuit board. Therefore, the potential risk of optical device failure caused by flux residue can be eliminated from the root, effectively improving signal integrity and assembly accuracy. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.
[0034] Figure 1 A schematic top view of a first embodiment of a circuit board assembly provided by the present invention;
[0035] Figure 2 for Figure 1 A schematic top view of a circuit board assembly;
[0036] Figure 3 for Figure 1 Schematic diagram of the coordination between the functional pads and the matching pads;
[0037] Figure 4 for Figure 1 Schematic diagram of the structure of the chip and circuit board;
[0038] Figure 5 for Figure 4 A schematic diagram of a top view of a circuit board;
[0039] Figure 6 A schematic top view of a second embodiment of a circuit board assembly provided by the present invention;
[0040] Figure 7 This is a schematic top view of a third embodiment of a circuit board assembly provided by the present invention.
[0041] Description of Figure Numbers:
[0042] 100. Circuit board assembly; 1. Circuit board; 11. Mating pad; 11a. Mating pad group; 111. Positioning pad; 111a. Pad segment; 112. Second mating pad; 113. Third mating pad; 12. Capacitor; 13. Reinforcement plate; 131. Avoidance hole; 2. Chip; 21. Functional pad; 3. Metal wire.
[0043] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION
[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0045] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.
[0046] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.
[0047] The invention provides a circuit board assembly and an electronic device, aiming to solve the problem of optical device failure caused by flux residue.
[0048] See also Figure 1 , Figure 2 and Figure 4 In one embodiment of the present invention, a circuit board assembly 100 includes a circuit board 1 and a chip 2, wherein the circuit board 1 has a first side and a second side opposite to each other, the first side of the circuit board 1 has at least one mounting area, and the circuit board 1 is provided with a plurality of matching pads 11 on the periphery of the mounting area; the chip 2 is arranged in the mounting area, and a plurality of functional pads 21 are arranged on the periphery of the end surface of the chip 2 facing away from the circuit board 1, and each of the functional pads 21 is connected to each of the matching pads 11 through a metal wire 3.
[0049] In the technical solution of the present invention, the matching pad 11 on the circuit board 1 is connected to the functional pad 21 on the chip 2 through a metal wire 3. The metal wire 3 is connected to the pad by first melting the end of the metal wire 3 at high temperature, and then connecting it to the metal pad as a whole, thereby completing the splicing. The entire assembly process does not involve solder paste and flux, and can also ensure the connection state of the chip 2 and the circuit printed on the circuit board 1. Therefore, the potential risk of optical device failure caused by flux residue can be eliminated from the root, effectively improving signal integrity and assembly accuracy.
[0050] Specifically, two opposite sides of the circuit board 1 along its thickness direction are referred to as the first side and the second side. The first direction and the second direction are two sides intersecting on a horizontal plane, which may correspond to the length direction and the width direction of the circuit board 1 .
[0051] It should be noted that the plurality of metal wires 3 are arranged at intervals, that is, the plurality of metal wires 3 are arranged side by side and cannot cross each other, because crossing of the metal wires 3 may cause a short circuit risk.
[0052] The present invention does not limit the material of the metal wire 3, which may be a gold wire, a silver wire, a copper wire, a copper-palladium alloy wire, etc. Gold wire is preferred because it has the best stability.
[0053] In order to reduce the overall occupied space of the product, the arrangement of the matching pads 11 on the circuit board 1 is reasonably arranged according to the arrangement of the functional pads 21 on the chip 2. The pads on the chip 2 may be arranged in only one row or in two rows.
[0054] Specifically, in some embodiments, the mounting area has a plurality of sides, the plurality of sides including two first sides arranged opposite to each other in a first direction, and two second sides arranged opposite to each other in a second direction; the plurality of mating pads 11 are arranged corresponding to at least one of the sides of the mounting area. That is, when the mating pads 11 are arranged, they should be arranged as concentratedly as possible, so as to make the layout compact and save space.
[0055] Specifically, in one embodiment, the chip 2 has two first side edges opposite to each other in the first direction, and at least one of the first side edges is provided with a plurality of the functional pads 21 to form a functional pad group, and the plurality of functional pads 21 in the functional pad group are first functional pads; the plurality of mating pads 11 correspond to at least one mating pad group 11a of the functional pad group, and the plurality of mating pads 11 in the mating pad group 11a are first mating pads, and the plurality of the first mating pads are arranged one-to-one with the plurality of the first functional pads, and at least part of the plurality of the first mating pads are arranged along the corresponding first side edge. The first mating pad should be arranged adjacent to the first functional pad, and preferably as many first mating pads as possible should be arranged on the same side edge of the mounting area, so as to facilitate the corresponding connection and mating of the metal wire 3.
[0056] The first mating pad on the circuit board 1 needs to consider the circuit wiring and volume of the printed circuit. Therefore, when arranging, the space occupied by a single first mating pad is larger than the space occupied by a single first functional pad, and the distance between two adjacent first mating pads is also larger than the distance between two adjacent first functional pads. If multiple first mating pads are set on the same side of the installation area and arranged along the same straight line, the overall size in a single direction may be too large, affecting the size of the circuit board 1.
[0057] Therefore, in some embodiments, in at least one of the mating pad groups 11a, other parts of the plurality of first mating pads are arranged corresponding to at least one of the second sides. That is, the plurality of first mating pads are partially arranged along the first direction and partially arranged along the second direction, and the number of first mating pads arranged in the two directions is different. Considering the wiring matching and size layout, the first mating pad is preferentially arranged on the side adjacent to the first functional pad and arranged in parallel with the first functional pad, and the first mating pad of the first functional pad corresponding to the edge position that affects the size is arranged on the side perpendicular to the arrangement direction of the first functional pad.
[0058] Please refer to Figure 7 In the third embodiment, the plurality of first mating pads in the mating pad group 11a are distributed in a U shape, and the plurality of first mating pads include a plurality of first pads and a plurality of second pads. The plurality of first pads are located at the two second sides of the mounting area and arranged along the first direction; the plurality of second pads are located at the first side of the mounting area and arranged along the second direction. At this time, the plurality of first mating pads are distributed at the three adjacent sides of the mounting area, and the number of the first pads and the plurality of second pads are not equal. This is to take into account the setting spacing between the mating pad 11 and the functional pad 21, so as to facilitate the arrangement of the metal wire 3. The design of the distribution method distributes the size to the first direction and the second direction, which is conducive to reducing the volume of the circuit board.
[0059] Please refer to Figure 6 In the second embodiment, in at least one of the mating pad groups 11a, the plurality of first mating pads corresponding to the first side are distributed in at least two rows in the first direction. In this embodiment, when the arrangement of the plurality of first mating pads affects the size, the plurality of first mating pads can also be arranged in two rows on the same side, so as to avoid excessive increase in the size in the second direction, and compensate for it by increasing the portion in the first direction. It should be understood that the number of the first mating pads in the two mating pad groups 11a is not equal. The number of the first mating pads in the row close to the chip 2 is greater than that in the other row.
[0060] For further information, please refer to Figure 2 The spacing d1 between two adjacent rows of mating pad groups 11a is related to the copper thickness of the wiring layer of the circuit board 1. The larger the copper thickness, the larger the value should be. For example, when the copper thickness is 0.1mm, the minimum value of d1 is 0.075mm.
[0061] Furthermore, the spacing d2 between two adjacent mating pads 11 in the mating pad group 11a is also related to the copper thickness of the wiring layer of the circuit board 1. The larger the copper thickness, the larger the value should be. For example, when the copper thickness is 0.1 mm, the minimum value of d2 is 0.075 mm.
[0062] It should be understood that in the above-mentioned embodiments, regarding the arrangement of the first mating pad, factors such as the total length in the first direction, the total length in the second direction, and the metal wires 3 cannot cross should be considered, and a reasonable layout should be performed based on the different arrangements of the functional pads 21 on the chip 2.
[0063] For example, see Figure 1 to Figure 2 In the first embodiment, two functional pad groups are provided and are correspondingly provided at the two first side edges; correspondingly, two matching pad groups 11a are provided. The arrangement of the two matching pad groups 11a may also be different.
[0064] In order to further shorten the total length of the plurality of mating pads 11 along the arrangement direction thereof, please refer to Figure 1 , the plurality of mating pads 11 include two second mating pads 112 with the same electrical properties, and the two second mating pads 112 fit each other; that is, the two second mating pads 112 with the same electrical properties fit closely together, thereby saving the size of the arrangement interval between the two, making the arrangement of the plurality of mating pads 11 more compact. It should be understood that the arrangement direction of the two second mating pads 112 is consistent with the arrangement direction of the mating pad group 11a, which may be along the first direction or along the second direction.
[0065] The present invention does not limit the electrical signal corresponding to the second mating pad 112 , for example, it may be a GND, POWER or other signal.
[0066] Considering the integrity of the differential signal, the plurality of mating pads 11 include two third mating pads 113 whose electrical properties are the positive and negative electrodes of the differential signal. The two third mating pads 113 are arranged corresponding to the same side of the mounting area and are arranged side by side along the length direction of the corresponding side. The positive and negative signals of the differential signal need to be designed with equal length, so the corresponding third mating pads 113 need to be arranged in the same row, so as to facilitate the differential line number wiring design and equal length design. That is, the two third mating pads 113 should be arranged in the same direction as the mating pad group 11a in which they are located, and cannot be arranged separately in two mating pad groups 11a.
[0067] It should be noted that avoiding designing pulse signals such as switch signals, clk signals, or power signals next to differential signals can provide a shorter loop for differential signals, reduce the interference of pulse signals such as switch signals, clk signals, or power signals on differential signals, and improve the quality of differential signals. Therefore, reasonable avoidance should be made when designing the corresponding matching pads 11. In addition to differential signals, matching pads 11 corresponding to clk signals should also be designed next to matching pads 11 corresponding to GND signals to avoid designing pulse signals such as switches or power signals.
[0068] In addition, the outer shape of the mating pad 11 is preferably set to be a rectangle, and the long side direction of the rectangle is perpendicular to the straight line where the functional pad 21 is located, so as to further reduce the package width.
[0069] Please refer to Figure 3 The projection of the metal wire 3 on the circuit board 1 is inclined to the vertical line of the corresponding side of the chip 2, and the angle of inclination is α, where α≤45°. This angle design also defines the azimuth relationship between the center of the corresponding functional pad 21 and the center of the matching pad 11. If the inclination angle is too large, it will increase the difficulty of wire bonding and increase the length of the metal wire 3, resulting in an increase in cost.
[0070] Furthermore, the size of the mating pad 11 in the first direction is L1, and the size of the mating pad 11 in the second direction is W1, wherein L1≥2*w1; and / or, W1≥mating pad molding design tolerance+0.05mm. The actual size is to facilitate punching and filling metal wires 3.
[0071] When designing, firstly, the arrangement design of the matching pads 11 on the circuit board 1 is carried out according to the chip 2 material. After the circuit board 1 is processed, the chip 2 is assembled. Therefore, the installation positioning of the chip 2 needs to be considered during assembly, so as to match the orientation of the functional pad 21 and the matching pad 11. In some embodiments, the circuit board 1 is provided with at least two positioning pads 111 on the periphery of the installation area, and the two positioning pads 111 are arranged on opposite sides of the chip 2 along the direction of the diagonal of the chip 2. The chip 2 is positioned by the center of the line connecting the two positioning pads 111. It should be understood that the center of the line connecting the two positioning pads 111 may coincide with the center of the chip 2, or may be staggered. Please refer to Figure 1 The center of the line connecting the two positioning pads 111 coincides with the center of the chip 2. Please refer to Figure 6 The center of the line connecting the two positioning pads 111 is offset from the center of the chip 2, so when installing, it is necessary to install according to the designed offset of O and O'.
[0072] It should be understood that the design number of the positioning pads 111 also needs to take the size layout into consideration. When there is enough space and the external size of the circuit board 1 is not greatly affected, four positioning pads 111 can be provided, corresponding to the four corners of the chip 2. When the installation space is limited, the positioning pad 111 can also be connected to the circuit to be used as a matching pad 11, and at the same time play the role of positioning and connecting the chip 2.
[0073] Furthermore, each positioning pad 111 includes two pad segments 111a arranged at an angle, and the two pad segments 111a correspond to two adjacent sides of the chip 2. That is, the positioning pad 111 is L-shaped, and the design of the pad segments 111a is helpful for reference in chip 2 installation.
[0074] In other embodiments, the shape of the positioning pad 111 may also be set to be circular, +-shaped, etc.
[0075] Specifically, the size of the positioning pad 111 along the second direction is L2, L2 ≥ 0.2mm; the size of the positioning pad 111 along the first direction is W2, where W2 ≥ circuit board size design tolerance + 0.05mm. The larger the size of the positioning pad 111, the easier it is to identify. The processing technology of the positioning pad 111 generally performs a window design on the layer structure of the circuit board 1. The ink layer is smaller than the wiring layer window design. Therefore, the size corresponding to W2 and L2 here should be the size of the ink layer window. The window size of the wiring layer should add the ink layer manufacturing tolerance on the basis of L2 and W2.
[0076] It should be noted that, when the positioning pad 111 is composed of two pad segments 111 a , W2 is the width of the corresponding pad segment 111 a in the first direction, rather than the total width of the positioning pad 111 in the first direction.
[0077] The spacing between the positioning pad 111 and the adjacent mating pad 11 is D1, where D1≥chip size design tolerance+positioning pad molding design tolerance+chip mounting design tolerance+0.05mm. The chip mounting design tolerance is the allowable deviation tolerance of the center position of the chip 2 when it is attached and fixed on the circuit board 1, and the positioning pad molding design tolerance is the allowable error range of the external dimensions of the positioning pad 111 when it is processed on the circuit board 1.
[0078] The distance between the mating pad 11 and the chip 2 is D2, wherein D2=chip size design tolerance+mating pad molding design tolerance+chip mounting design tolerance+0.05 mm.
[0079] To avoid the effects of flux removal on optical devices, please refer to Figures 4 to 5 , a plurality of capacitors and resistors 12 are arranged on the second side of the circuit board 1. In this way, the capacitors and resistors can be arranged to improve and realize the functions of the circuit board 1, and the capacitors and resistors 12 are arranged on the back of the chip 2. Even if the capacitors and resistors 12 are fixed by soldering, they will not affect the optical devices on the first side.
[0080] Considering that conventional flexible circuit boards are soft boards as a whole due to their material, a reinforcing plate 13 is provided on the second side of the circuit board 1, and a plurality of avoidance holes 131 are penetrated on the reinforcing plate 13; the plurality of resistors 12 are located in the plurality of avoidance holes 131. The reinforcing plate 13 is fixed to the second side of the circuit board 1 to improve the structural strength of the circuit board 1, and the avoidance holes 131 can expose the resistors 12, thereby avoiding the resistors 12. It should be noted that the material of the reinforcing plate 13 is not limited, and it can be a metal material, such as a steel plate, or a non-metal material, and can be reasonably selected according to actual design requirements.
[0081] Furthermore, the gap size between the resistor 12 and the avoidance hole 131 should be reasonably set to ensure the function of the resistor 12. The spacing between the resistor 12 and the corresponding avoidance hole 131 is D3, where D3≥reinforcement board installation design tolerance+chip installation design tolerance+0.05mm. 0.05mm is a safety dimension. The reinforcement board installation design tolerance is the process requirement tolerance for the reinforcement board 13 to be attached to the circuit board 1. The chip installation design tolerance is the allowable deviation tolerance of the center position of the chip 2 when it is attached and fixed to the circuit board 1.
[0082] Based on the above embodiment, when designing the arrangement of the mating pads 11 of the circuit board assembly 100, it is necessary to consider the arrangement and number of the functional pads 21 on the chip 2, the size of the circuit board 1, the signal distribution design on the circuit board 1, etc. By reducing the package mating size of the chip 2 and the circuit board 1 through reasonable arrangement, it helps to reduce the overall size of the product.
[0083] In this design scheme, the design of pads such as differential signals and clk signals is conducive to improving signal integrity; the design of positioning pads 111 is conducive to improving the accuracy of back-end assembly and reducing the size of the device package to a certain extent, realizing the miniaturized design of the product, reducing the length of the arrangement of the matching pads 11, reducing production costs, and increasing the competitive advantage of the product.
[0084] The present invention further proposes an electronic device, which includes a circuit board assembly 100. The specific structure of the circuit board assembly 100 refers to the above embodiment. Since the electronic device adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here. The present invention does not limit the specific type of the electronic device, for example, it can be an AR lithography product, specifically a semiconductor device.
[0085] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.
Claims
1. A circuit board assembly, characterized in that: include: A circuit board having a first side and a second side opposite to each other, wherein the first side of the circuit board has at least one mounting area, and the circuit board is provided with a plurality of mating pads at the periphery of the mounting area; and The chip is arranged in the installation area, and a plurality of functional pads are arranged around the end surface of the chip facing away from the circuit board, and each of the functional pads is connected to each of the matching pads through a metal wire.
2. The circuit board assembly according to claim 1, wherein: The installation area has a plurality of side edges, the plurality of side edges comprising two first side edges arranged opposite to each other in a first direction, and two second side edges arranged opposite to each other in a second direction; The plurality of mating pads are disposed corresponding to at least one side of the mounting area.
3. The circuit board assembly according to claim 2, wherein: The chip has two first side edges opposite to each other in a first direction, at least one of the first side edges is provided with a plurality of the functional pads to form a functional pad group, and the plurality of functional pads in the functional pad group are first functional pads; The multiple mating pads correspond to at least one mating pad group formed by the functional pad group, the multiple mating pads in the mating pad group are first mating pads, the multiple first mating pads are arranged in one-to-one correspondence with the multiple first functional pads, and at least part of the multiple first mating pads are arranged along the corresponding first side.
4. The circuit board assembly according to claim 3, wherein: In at least one of the mating pad groups, other portions of the plurality of the first mating pads are arranged corresponding to at least one of the second sides.
5. The circuit board assembly according to claim 3, wherein: The functional pad groups are provided with two and are correspondingly arranged at the two first side edges; Correspondingly, two matching pad groups are provided.
6. The circuit board assembly according to claim 3, wherein: In at least one of the mating pad groups, a plurality of the first mating pads corresponding to the first side are distributed in at least two rows in a first direction.
7. The circuit board assembly according to claim 2, wherein: The plurality of mating pads include two second mating pads having the same electrical properties, and the two second mating pads are arranged in a bonded manner.
8. The circuit board assembly according to claim 2, wherein: The plurality of mating pads include two third mating pads whose electrical properties are positive and negative electrodes of differential signals. The two third mating pads are arranged corresponding to the same side and are arranged side by side along the length direction of the corresponding side.
9. The circuit board assembly according to claim 2, wherein: The projection of the metal wire on the circuit board is inclined to the vertical line of the corresponding side of the chip, and the angle of inclination is α, wherein: α≤ 45° 。 10. The circuit board assembly according to claim 2, wherein: The size of the matching pad in the first direction is L1, and the size of the matching pad in the second direction is W1, wherein, L1 ≥ 2*w1; and / or, W1≥match the pad molding design tolerance + 0.05mm.
11. The circuit board assembly according to claim 1, wherein: The circuit board is provided with at least two positioning pads at the periphery of the mounting area, and the two positioning pads are arranged on two opposite sides of the chip along the direction where the diagonal line of the chip is located.
12. The circuit board assembly according to claim 11, wherein: Each of the positioning pads includes two pad segments arranged at an angle, and the two pad segment pairs correspond to two adjacent sides of the chip respectively.
13. The circuit board assembly according to claim 11, wherein: The dimension of the positioning pad along the second direction is L2, L2 ≥ 0.2 mm; and / or, The dimension of the positioning pad along the first direction is W2, wherein W2≥circuit board dimension design tolerance+0.05 mm.
14. The circuit board assembly according to claim 11, wherein: The spacing between the positioning pad and the adjacent matching pad is D1, wherein D1≥chip size design tolerance+positioning pad molding design tolerance+chip mounting design tolerance+0.05 mm.
15. The circuit board assembly according to claim 1, wherein: The distance between the mating pad and the chip is D2, wherein D2=chip size design tolerance+mating pad molding design tolerance+chip mounting design tolerance+0.05 mm.
16. The circuit board assembly according to claim 1, wherein: A plurality of capacitance and resistance components are arranged on the second side of the circuit board.
17. The circuit board assembly according to claim 16, wherein: A reinforcing plate is provided on the second side of the circuit board, and a plurality of avoidance holes are penetrated on the reinforcing plate; The plurality of capacitance components are located in the plurality of avoidance holes.
18. The circuit board assembly according to claim 17, wherein: The distance between the capacitance and the corresponding avoidance hole is D3, wherein D3≥reinforcement plate installation design tolerance+chip installation design tolerance+0.05mm.
19. An electronic device comprising the circuit board assembly according to any one of claims 1 to 18.