WO2022228061A1 - 电路板组件及电子设备 - Google Patents

电路板组件及电子设备 Download PDF

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Publication number
WO2022228061A1
WO2022228061A1 PCT/CN2022/085354 CN2022085354W WO2022228061A1 WO 2022228061 A1 WO2022228061 A1 WO 2022228061A1 CN 2022085354 W CN2022085354 W CN 2022085354W WO 2022228061 A1 WO2022228061 A1 WO 2022228061A1
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WO
WIPO (PCT)
Prior art keywords
circuit board
substrate
bracket
thermal expansion
expansion coefficient
Prior art date
Application number
PCT/CN2022/085354
Other languages
English (en)
French (fr)
Inventor
吴豫陇
李卫强
Original Assignee
华为技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to EP22794532.6A priority Critical patent/EP4319497A1/en
Publication of WO2022228061A1 publication Critical patent/WO2022228061A1/zh
Priority to US18/494,849 priority patent/US20240074042A1/en

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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/0271—Arrangements for reducing stress or warp in rigid printed circuit boards, e.g. caused by loads, vibrations or differences in thermal expansion
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/18—Printed circuits structurally associated with non-printed electric components
    • H05K1/181—Printed circuits structurally associated with non-printed electric components associated with surface mounted components
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/04—Assemblies of printed circuits
    • H05K2201/044—Details of backplane or midplane for mounting orthogonal PCBs
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/06—Thermal details
    • H05K2201/068—Thermal details wherein the coefficient of thermal expansion is important
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/09—Shape and layout
    • H05K2201/09009—Substrate related
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/10—Details of components or other objects attached to or integrated in a printed circuit board
    • H05K2201/10227—Other objects, e.g. metallic pieces
    • H05K2201/10409—Screws
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/10—Details of components or other objects attached to or integrated in a printed circuit board
    • H05K2201/10431—Details of mounted components
    • H05K2201/10598—Means for fastening a component, a casing or a heat sink whereby a pressure is exerted on the component towards the PCB

Definitions

  • the present application relates to the technical field of electronic products, and in particular, to a circuit board assembly and electronic equipment.
  • a substrate is provided on the side of the circuit board carrying the large-sized chip facing away from the chip, so as to improve the mechanical strength of the circuit board, thereby enhancing the protection and fixation of the chip.
  • the deformation amount of the substrate and the circuit board is different, which makes the circuit board deform in the substrate.
  • the solder joint between the circuit board and the chip is subjected to additional structural deformation stress, which reduces the thermal cycle fatigue life of the solder joint, resulting in a shortened service life of the circuit board assembly.
  • the present application discloses a circuit board assembly and electronic equipment.
  • the circuit board assembly is applied to the electronic equipment, and the electronic equipment has a long service life.
  • the circuit board assembly includes a circuit board on which large-sized chips are mounted and a substrate.
  • the substrate is arranged on the side of the circuit board facing away from the chip, and is connected to the circuit board.
  • the present application provides a circuit board assembly, which is characterized by comprising a circuit board and a substrate fixed on one side of the circuit board, the circuit board has a first thermal expansion coefficient, the substrate has a second thermal expansion coefficient, and the second thermal expansion coefficient The difference between the coefficient and the first coefficient of thermal expansion is less than or equal to 30% of the first coefficient of thermal expansion.
  • the thermal expansion coefficients of the substrate and the circuit board are close, so that when the temperature of the circuit board, the substrate and other structures changes relative to the normal temperature, the deformation amount of the substrate and the circuit board is close to prevent the circuit board from being deformed by the substrate
  • the influence of the force produces non-self-deformation, the deformation that keeps the circuit board in the bare state.
  • the solder joint will not be subjected to downward structural deformation stress, which improves the thermal cycle fatigue life of the solder joint.
  • the circuit board generally uses resin to achieve the insulating function.
  • the thermal expansion coefficient of the resin is high, that is, the thermal expansion coefficient of the circuit board is high.
  • the substrate is generally made of materials with high mechanical strength such as metal and ceramics, such as stainless steel, aluminum alloy, etc., that is, the thermal expansion coefficient of the substrate is low. Understandably, materials with high mechanical strength generally have lower coefficients of thermal expansion.
  • the thermal expansion coefficients of the substrate and the circuit board are close. Although part of the mechanical strength is sacrificed, the protective effect of the substrate is weakened, but the deformation loss caused by the mismatch of the thermal expansion coefficient between the substrate and the circuit board is reduced. match.
  • this embodiment reduces the substrate deformation force on the circuit board caused by the substrate deformation, further reduces the non-self-deformation caused by the circuit board, and eliminates or reduces the stress on the solder joints. Therefore, the thermal cycle fatigue life of solder joints can be improved, and the service life of circuit board components can be increased.
  • the substrate includes a first backplane and a second backplane
  • the second backplane is located on the side of the first backplane facing away from the circuit board, and the thermal expansion coefficient of the first backplane is smaller than that of the second backplane.
  • At least one of the first backplane and the second backplane is fixedly connected to the circuit board.
  • the thermal expansion coefficient of the first backplane is smaller than the thermal expansion coefficient of the second backplane, so that the thermal deformation of the first backplane is smaller than the thermal deformation of the second backplane.
  • the substrate will bulge toward the side where the second backplane with a large amount of deformation is located, that is, both ends of the substrate will be lifted upwards to match the deformation mode of the circuit board. Therefore, when the temperature of the circuit board, substrate and other structures changes relative to the normal temperature, the convex direction of the substrate is the same as the convex direction of the circuit board, so as to prevent the circuit board from being affected by the deformation force of the substrate and causing non-self. Deformation, the deformation when the circuit board is kept in the bare state. At the same time, the solder joint will not be subjected to downward structural deformation stress, which improves the thermal cycle fatigue life of the solder joint and the service life of the circuit board assembly.
  • the thermal expansion coefficient of the substrate can be close to that of the circuit board, that is, the difference between the second thermal expansion coefficient and the first thermal expansion coefficient can be greater than 30% of the first thermal expansion coefficient, so as to further reduce the The effect of substrate deformation forces.
  • the thermal expansion coefficient of the substrate is the total thermal expansion coefficient of the fixed structure composed of the first backplane and the second backplane.
  • the circuit board assembly further includes an intermediate buffer member, opposite sides of the intermediate buffer member are fixedly connected to the circuit board and the substrate respectively, and the intermediate buffer member can elastically deform under the action of external force.
  • the intermediate buffer member can be deformed by force, and the deformation performance of the intermediate buffer member can reduce the connection between the circuit board and the substrate, offset the difference in deformation between the circuit board and the substrate, and avoid The deformation of the circuit board is affected by the deformation force of the substrate, and the deformation of the circuit board is maintained when it is in a bare state to improve the thermal cycle fatigue life of the solder joints.
  • the circuit board assembly further includes:
  • Fixing piece, the circuit board and the substrate are stacked and arranged with a gap between them, the fixing piece is arranged at both ends of the circuit board, the fixing piece is inserted into the circuit board, and is fixedly connected to the substrate, when the circuit board assembly is heated, the circuit board and the lining The relative position of the bottom changes;
  • the first buffer member is located on the side of the circuit board facing away from the substrate and contacts the circuit board, the fixing member is inserted into the first buffer member, and the first buffer member is deformed when the circuit board assembly is heated;
  • the second buffer member is located between the circuit board and the substrate and contacts the circuit board and the substrate, the fixing member is inserted into the second buffer member, and the second buffer member is deformed when the circuit board assembly is heated.
  • the first buffer member when the circuit board assembly is heated, the relative position of the circuit board and the substrate changes, and the first buffer member is deformed, so as to reduce the connection between the fixing member and the circuit board and increase the level of the circuit board.
  • the deformation space in the direction prevents the deformation of the circuit board from being restricted by the fixing parts.
  • the second buffer member is deformed to reduce the connection between the circuit board and the substrate, increase the deformation space of the circuit board and the substrate in the horizontal direction, and avoid the deformation of the circuit board from being affected by the deformation force of the substrate.
  • the first buffer member and the second buffer member can reduce the connection effect of the fixing member on the circuit board and the substrate, and at the same time ensure the fastening effect of the fixing member, increase the deformation space of the circuit board and the substrate in the horizontal direction to avoid
  • the circuit board produces non-self deformation, maintains the deformation of the circuit board when it is in the state of bare board, and can further avoid the structural deformation stress of the solder joints, and improve the thermal cycle fatigue life of the solder joints and the service life of the circuit board components.
  • the buffer member may also be provided on the upper side or the lower side of the circuit board, so as to reduce the volume of the circuit board and its related components, and make the structure of the circuit board component more compact, which is not limited in this application.
  • the circuit board assembly further includes a bracket, the bracket is located on the side of the circuit board facing away from the substrate, two ends of the bracket are fixedly connected to both ends of the circuit board, and the middle part of the bracket is connected to the circuit board. A gap is formed between the middle parts of the boards, and the thermal expansion coefficient of the bracket is smaller than that of the circuit board.
  • the deformation of the bracket is smaller than that of the circuit board, so that an upward pressure can be applied to both ends of the circuit board.
  • the force can offset the diagonal downward substrate deformation force caused by the substrate deformation on the circuit board, avoid the non-self deformation of the circuit board, and maintain the deformation of the circuit board when the circuit board is in the state of the bare board. Under the structural deformation stress, improve the temperature cycle fatigue life of solder joints and the service life of circuit board components.
  • the bracket includes an upper bracket and a lower bracket that are stacked and fixedly connected, the upper bracket is located on the side of the lower bracket facing away from the circuit board, and at least one of the upper bracket and the lower bracket is Two ends of one are fixedly connected to the circuit board, a gap is formed between the middle part of the lower bracket and the middle part of the circuit board, and the thermal expansion coefficient of the upper bracket is smaller than that of the lower bracket.
  • the bracket when the temperature of the circuit board, substrate, bracket and other structures changes relative to the normal temperature, the bracket will exert upward force on both ends of the circuit board to further offset the effect of substrate deformation on the circuit
  • the diagonally downward substrate deformation force generated by the board maintains the deformation of the circuit board when it is in the bare state.
  • the solder joint will not be subjected to downward structural deformation stress, which improves the thermal cycle fatigue life of the solder joint.
  • the present application also provides a circuit board assembly, including a circuit board and a substrate fixedly connected to the circuit board, the substrate includes a first backplane and a second backplane, and the second backplane is located on the back of the first backplane To one side of the circuit board, the thermal expansion coefficient of the first backplane is smaller than that of the second backplane, and at least one of the first backplane and the second backplane is fixedly connected to the circuit board.
  • the first back plate may be a pre-galvanized steel plate
  • the second back plate may be an aluminum alloy steel plate.
  • the first backplane and the second backplane may also be made of other materials, as long as the thermal expansion coefficient of the first backplane can be smaller than that of the second backplane, which is not limited in this application.
  • the substrate may also adopt a structure of more than two layers, for example, three layers, etc., which is not limited in this application, as long as the thermal expansion of the multi-layer structure is satisfied when the temperature at the substrate changes relative to the normal temperature
  • the coefficient increases with the distance from the circuit board, and the convex direction of the substrate and the circuit board can be the same.
  • the circuit board assembly further includes an intermediate buffer member, opposite sides of the intermediate buffer member are fixedly connected to the circuit board and the substrate respectively, and the intermediate buffer member can elastically deform under the action of external force.
  • the circuit board assembly further includes:
  • Fixing parts, the circuit board and the substrate are stacked and a gap is formed between the two, the fixing parts are arranged at both ends of the circuit board, plug the circuit board, and fixedly connect the substrate, when the circuit board assembly is heated, the circuit board and the substrate are heated. relative position changes;
  • the first buffer member is located on the side of the circuit board facing away from the substrate and contacts the circuit board, the fixing member is inserted into the first buffer member, and the first buffer member is deformed when the circuit board assembly is heated;
  • the second buffer member is located between the circuit board and the substrate and contacts the circuit board and the substrate, the fixing member is inserted into the second buffer member, and the second buffer member is deformed when the circuit board assembly is heated.
  • the circuit board assembly further includes a bracket, the bracket is located on the side of the circuit board facing away from the substrate, two ends of the bracket are fixedly connected to both ends of the circuit board, and the middle part of the bracket is connected to the circuit board. A gap is formed between the middle parts of the boards, and the thermal expansion coefficient of the bracket is smaller than that of the circuit board.
  • the bracket includes an upper bracket and a lower bracket that are stacked and fixedly connected, the upper bracket is located on the side of the lower bracket facing away from the circuit board, and at least one of the upper bracket and the lower bracket is Two ends of one are fixedly connected to the circuit board, a gap is formed between the middle part of the lower bracket and the middle part of the circuit board, and the thermal expansion coefficient of the upper bracket is smaller than that of the lower bracket.
  • the present application further provides a circuit board assembly, comprising a circuit board, a substrate and a fixing member, the circuit board and the substrate are stacked and arranged with a gap formed therebetween, the fixing member is arranged at both ends of the circuit board, and the fixing member
  • the circuit board assembly also includes:
  • the first buffer member is located on the side of the circuit board facing away from the substrate and contacts the circuit board, the fixing member is inserted into the first buffer member, and the first buffer member is deformed when the circuit board assembly is heated;
  • the second buffer member is located between the circuit board and the substrate and contacts the circuit board and the substrate, the fixing member is inserted into the second buffer member, and the second buffer member is deformed when the circuit board assembly is heated.
  • the first buffer member adopts foam, rubber or spring
  • the second buffer member adopts foam, rubber, PTFE or spring
  • the buffer may be made of elastic materials such as rubber, foam, PTFE (poly tetrafluoroethylene, polytetrafluoroethylene), or a structure that can be elastically deformed under force, such as a spring.
  • the buffer member can adopt a bionic design structure, so as to better match the shape of the circuit board after deformation, and increase the fastening effect of the fixing member on the circuit board and the substrate.
  • the fixing member includes a fixedly connected limiter and a plug-in connector, the limiter protrudes outward relative to the peripheral side of the plug-in member, and the first buffer is located between the limiter and the circuit board. And contact the limiter and the circuit board.
  • the circuit board assembly further includes a bracket, the bracket is located on the side of the circuit board facing away from the substrate, two ends of the bracket are fixedly connected to both ends of the circuit board, and the middle part of the bracket is connected to the circuit board. A gap is formed between the middle parts of the boards, and the thermal expansion coefficient of the bracket is smaller than that of the circuit board.
  • the bracket includes an upper bracket and a lower bracket that are stacked and fixedly connected, the upper bracket is located on the side of the lower bracket facing away from the circuit board, and at least one of the upper bracket and the lower bracket is Two ends of one are fixedly connected to the circuit board, a gap is formed between the middle part of the lower bracket and the middle part of the circuit board, and the thermal expansion coefficient of the upper bracket is smaller than that of the lower bracket.
  • the upper bracket may be pre-galvanized steel plate, and the lower bracket may be aluminum alloy steel plate.
  • the upper bracket and the lower bracket can also be made of other materials, as long as the thermal expansion coefficient of the upper bracket can be smaller than that of the lower bracket, which is not limited in this application.
  • the bracket may adopt a double-layer structure, that is, it includes an upper bracket and a lower bracket arranged in layers.
  • the bracket can also adopt a structure with more than two layers, for example, three layers, etc., which is not limited in this application, as long as the thermal expansion of the multi-layer structure is satisfied when the temperature at the bracket changes relative to the normal temperature
  • the coefficient decreases as the distance between the multilayer structure and the circuit board increases, so that the convex direction of the bracket is the same as that of the circuit board.
  • the present application further provides a circuit board assembly, which includes a circuit board, a substrate and a bracket, the substrate is fixedly connected to the circuit board, the bracket is located on the side of the circuit board facing away from the substrate, and two sides of the bracket are located.
  • the ends are fixedly connected with both ends of the circuit board, a gap is formed between the middle part of the bracket and the middle part of the circuit board, and the thermal expansion coefficient of the bracket is smaller than that of the circuit board.
  • the bracket includes an upper bracket and a lower bracket that are stacked and fixedly connected, the upper bracket is located on the side of the lower bracket facing away from the circuit board, and at least one of the upper bracket and the lower bracket is Two ends of one are fixedly connected to the circuit board, a gap is formed between the middle part of the lower bracket and the middle part of the circuit board, and the thermal expansion coefficient of the upper bracket is smaller than that of the lower bracket.
  • the present application provides an electronic device including the above circuit board assembly, the circuit board assembly includes a chip, the chip is fixed on the side of the circuit board facing away from the substrate, and the electronic device has a long service life.
  • FIG. 1 is a partial structural schematic diagram of an electronic device provided by the present application in some embodiments.
  • FIG. 2A is a schematic structural diagram of the circuit board assembly shown in FIG. 1 in some embodiments;
  • FIG. 2B is a schematic structural diagram of the circuit board assembly shown in FIG. 1 in some other embodiments;
  • 3A is a schematic diagram of a deformation of the circuit board assembly in a bare board state
  • 3B is a schematic diagram of a deformation of a circuit board assembly using a conventional structure
  • FIG. 4 is a schematic diagram of a modification of the circuit board assembly shown in FIG. 2A in some embodiments provided in the present application;
  • FIG. 5 is a schematic diagram of a modification of the circuit board assembly shown in FIG. 2A in still other embodiments provided in the present application;
  • Fig. 6 is the deformation schematic diagram of the substrate shown in Fig. 5;
  • FIG. 7 is a schematic structural diagram of the circuit board assembly shown in FIG. 2A in still other embodiments provided by the present application;
  • FIG. 8 is a schematic diagram of a deformation of the circuit board assembly shown in FIG. 7;
  • FIG. 9 is a schematic structural diagram of the circuit board assembly shown in FIG. 2A in still other embodiments provided by the present application.
  • FIG. 10 is a schematic diagram of a deformation of the circuit board assembly shown in FIG. 9;
  • FIG. 11 is a schematic diagram of a modification of the circuit board assembly shown in FIG. 2A in some of the more embodiments provided in the present application.
  • FIG. 1 is a partial structural schematic diagram of an electronic device 100 provided by the present application in some embodiments.
  • the electronic device 100 may be an electronic product applied in the fields of signal transmission, access, computing, and wireless communication, for example, a server, a router, a mobile phone, a notebook computer, a television, a smart home device, a vehicle-mounted device, and the like.
  • the electronic device 100 may include a hollow casing 1 and an antenna 2 .
  • the antenna 2 can be used to receive and transmit signals, and realize wireless transmission of signals through electromagnetic waves.
  • the antenna 2 may be fixed to the outside of the casing 1 or may be installed inside the casing 1 .
  • the electronic device 100 may also not include the antenna 2, but use other signal transmission methods such as optical fibers, cables, etc., which are not limited in this application.
  • the housing 1 may include a housing cavity for accommodating the internal structure of the electronic device 100 .
  • the electronic device 100 may further include a circuit board assembly 3 mounted in the inner cavity of the housing.
  • the electronic device 100 may further include a heat sink (not shown) fixedly connected with the circuit board assembly 3 .
  • the heat sink can be made of aluminum alloy, brass or bronze in the form of a plate, a sheet, a multi-sheet and other structures, and is used to dissipate the heat of the circuit board assembly 3, so as to reduce the temperature of the circuit board assembly 3 and protect the circuit operational stability of the plate assembly 3 and increase its service life.
  • FIG. 2A is a schematic structural diagram of the circuit board assembly 3 shown in FIG. 1 in some embodiments.
  • the circuit board assembly 3 may include a chip 31 , a circuit board 32 , a substrate 33 and a fixing member 34 .
  • the circuit board 32 is fixedly connected to the substrate 33 , and the lower surface of the circuit board 32 can be attached to the upper surface of the substrate 33 .
  • the two components can be fixedly connected by a connecting piece.
  • the two components are fixedly connected, that is, the positional relationship of the two components is unchanged, but the positional relationship caused by the deformation of the connecting piece between the two components is allowed to change.
  • the terms "upper”, “lower”, “inner”, “outer” and other orientations in this application are descriptions with reference to the orientations of the attached drawings, and do not indicate or imply the indicated devices or elements. It must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation of the present application.
  • the circuit board 32 and the substrate 33 may be fixedly connected by fixing members 34 , and the fixing members 34 are provided at both ends of the circuit board 32 .
  • the fixing member 34 is inserted into the circuit board 32 and fixedly connected to the substrate 33 .
  • the circuit board 32 and the substrate 33 are stacked with a gap formed therebetween.
  • the fixing member 34 may be a fastener such as a screw, a rivet or the like.
  • the circuit board 32 can also be fixedly connected to the substrate 33 by means of gluing, welding or the like.
  • the substrate 33 may include a screw hole (not shown) with an opening facing the circuit board 32, and the inner wall of the screw hole is provided with an inner thread matched with the thread on the peripheral side of the screw.
  • the screw can extend into the screw hole, and can be fixedly connected with the substrate 33 by being tightly matched with the screw hole.
  • the chip 31 is fixed on the side of the circuit board 32 facing away from the substrate 33 and is electrically connected therewith.
  • the chip 31 can be used to realize the transmission of signals, and can also process the signals.
  • the chip 31 may be a large-sized ASIC (application specific integrated circuit, an integrated circuit for a specific application) chip, which can be specially designed and manufactured according to the requirements of the product to achieve specific function enhancement, and has higher processing speed and Low energy consumption.
  • the chip 31 may also be a general-purpose chip such as a CPU (central processing unit, central processing unit), a GPU (graphics processing unit, an image processing unit), or a semi-custom chip such as an FPGA (field programmable gate array, field programmable gate array).
  • the application embodiments do not limit this.
  • the chip 31 can be fixedly and electrically connected to the circuit board 32 through solder joints.
  • the chip 31 can be connected to the circuit board 32 by means of a BGA (ball grid array package), or can be connected to the circuit board 32 by means of an SMT (surface mounted technology, surface mount technology) or the like.
  • the chip 31 may also be fixedly and electrically connected to the circuit board 32 by means of conductive glue or the like.
  • the present application does not limit the connection method of the chip 31 and the circuit board 32 .
  • the electronic device 100 adopts a large-sized ASIC chip to meet the requirements of high-power use, and at the same time, it also generates a large amount of heat, so that the circuit board 32 and the substrate 33 are heated to generate thermal strain.
  • the chip 31 is connected to the circuit board 32 by using a BGA as an example for description.
  • the circuit board assembly 3 may also include a plurality of solder joints (not shown), and the solder joints are arranged between the chip 31 and the circuit board 32 and are fixedly connected with the chip 31 and the circuit board 32 to realize the connection between the chip 31 and the circuit board 32 . Fixed connection and electrical connection.
  • the horizontal direction X is a direction parallel to the plane where the upper surface of the circuit board 32 is located when it is not deformed.
  • the horizontal direction X may be any direction parallel to the plane on which the upper surface of the circuit board 32 is undeformed, which is not limited in this embodiment of the present application.
  • FIG. 2B is a schematic structural diagram of the circuit board assembly 3 shown in FIG. 1 in other embodiments.
  • the circuit board assembly 3 may also include a support member 35 .
  • the support member 35 may be fixed to the side of the substrate 33 facing the circuit board 32 and protrude relative to the upper surface of the substrate 33 . At this time, there is a gap between the lower surface of the circuit board 32 and the upper surface of the substrate 33 , leaving sufficient space for the deformation of the circuit board 32 .
  • the support member 35 may contact or abut against the lower surface of the circuit board 32 facing away from the chip 31 , and the fixing member 34 passes through the circuit board 32 and is fixedly connected to the support member 35 .
  • the fixing member 34 when the fixing member 34 is a screw, the supporting member 35 may be a nut matched with the screw, and the screw passes through the circuit board 32 and is locked with the nut.
  • the nut may be fixed on the side of the substrate 33 facing the circuit board 32 and contact or abut against the lower surface of the circuit board 32 .
  • FIG. 3A is a schematic diagram of a deformation of the circuit board assembly 4 in a bare board state, wherein the partially enlarged view in FIG. 3A shows a schematic diagram of the force of the solder joint 41 .
  • the circuit board assembly 4 in the bare board state includes the circuit board 42 , the chip 43 soldered to the circuit board 42 , and the solder joints 41 between the circuit board 42 and the chip 43 , and the circuit board assembly 4 in the bare board state is not in the circuit A substrate is provided on the side of the board 42 facing away from the chip 43 .
  • the circuit board 42 is generally used to carry electronic components and to achieve electrical connections between the electronic components.
  • the circuit board assembly 4 is deformed. Specifically, when the temperature of the chip 43 and the circuit board 42 increases relative to the normal temperature, that is, when the chip 43 and the circuit board 42 are at high temperature, the circuit board 42 and the chip 43 will be deformed, the middle is concave, and the two ends are raised, Shows a "smiley" shape.
  • the circuit board 42 and the chip 43 When the temperature of the chip 43 and the circuit board 42 is lower than normal temperature, that is, when the chip 43 and the circuit board 42 are at low temperature, the circuit board 42 and the chip 43 will bulge in the middle, showing a "crying face" shape. Also, the deformation amount of the circuit board 42 is larger than the deformation amount of the chip 43 .
  • the upper and lower ends of the solder joints 41 are fixedly connected to the chip 43 and the circuit board 42, respectively. The mismatch of the deformation of the chip 43 and the circuit board 42 causes the upper and lower ends of the solder joints 41 to be sheared in the horizontal direction X and in opposite directions, respectively. force.
  • the circuit board 42 when the temperature of the chip 43 and the circuit board 42 returns to normal temperature, the circuit board 42 will recover from the deformed state to a state of no deformation; when the temperature of the chip 43 and the circuit board 42 changes relative to the normal temperature, the circuit board 42 will be deformed again, and shear force will be generated on the solder joint 41, and this cycle will cause the solder joint 41 to generate thermal cycle fatigue.
  • the temperature at the circuit board assembly 4 can be considered as normal temperature when the temperature is in the range of 20°C to 30°C, the temperature can be considered as high temperature when the temperature is in the range from normal temperature to 200°C, and the temperature is between minus 100°C and normal temperature.
  • the range can be considered as low temperature.
  • FIG. 3B is a schematic diagram of a deformation of the circuit board assembly 5 with a conventional structure, wherein the partially enlarged view in FIG. 3B shows a schematic diagram of the force of the solder joint 51 .
  • the circuit board assembly 5 using the conventional structure includes a chip 53 , a circuit board 54 , a substrate 55 , a fixing member 52 and a solder joint 51 .
  • the chip 53 is soldered to the circuit board 54 , and the solder joint is located between the circuit board 54 and the chip 53 .
  • the fixing members 52 are disposed on both ends of the circuit board 54 .
  • the fixing member 52 is inserted into the circuit board 54 and fixedly connected to the substrate 55 .
  • the substrate 55 will be connected to the circuit board 54 through the connecting action of the fixing member 52 .
  • An oblique downward substrate deformation force is generated, resulting in a change in the deformation mode of the circuit board 54 when heated, resulting in non-self deformation.
  • the two ends of the circuit board 54 are subjected to the deformation force of the substrate, and bend downward to present an "M" shape, so that the solder joint 51 is subjected to the shear force in the horizontal direction X, and also receives the downward structural deformation stress. , resulting in an increased probability of cracks in the solder joints 51 , which significantly reduces the thermal cycle fatigue life of the solder joints 51 .
  • FIG. 4 is a schematic diagram of a modification of the circuit board assembly 3 shown in FIG. 2A in some embodiments provided in the present application.
  • the circuit board 32a may have a first coefficient of thermal expansion (CTE)
  • the substrate 33a may have a second coefficient of thermal expansion.
  • the second thermal expansion coefficient may be close to the first thermal expansion coefficient, that is, the difference between the second thermal expansion coefficient and the first thermal expansion coefficient is less than or equal to 30% of the first thermal expansion coefficient.
  • the second thermal expansion coefficient may be equal to the first thermal expansion coefficient, and the difference between the second thermal expansion coefficient and the first thermal expansion coefficient may also be 1%, 5%, or 15% of the first thermal expansion coefficient. This is not limited.
  • the thermal expansion coefficients of the substrate 33a and the circuit board 32a are close, so that when the temperature of the circuit board 32a, the substrate 33a and other structures changes relative to the normal temperature, the substrate 33a
  • the deformation amount of the circuit board 32a is close to that of the circuit board 32a, so as to avoid the non-self deformation of the circuit board 32a under the influence of the deformation force of the substrate, and maintain the deformation of the circuit board 32a when it is in a bare state.
  • the solder joints 36a will not be subjected to downward structural deformation stress, thereby improving the thermal cycle fatigue life of the solder joints 36a.
  • the circuit board 32a generally uses resin to achieve the insulating function.
  • the thermal expansion coefficient of the resin is high, that is, the thermal expansion coefficient of the circuit board 32a is high.
  • the substrate 33a is generally made of materials with high mechanical strength such as metals and ceramics, such as stainless steel, aluminum alloys, etc., that is, the thermal expansion coefficient of the substrate 33a is relatively low. . Understandably, materials with high mechanical strength generally have lower coefficients of thermal expansion.
  • the deformation amount of the circuit board 32a with a higher thermal expansion coefficient is larger than the deformation amount of the substrate 33a with a lower thermal expansion coefficient, resulting in the difference between the substrate 33a and the circuit board 32a.
  • the thermal expansion coefficient of the substrate 33a and the circuit board 32a is close. Although a part of the mechanical strength is sacrificed, the protective effect of the substrate 33a is weakened, but the thermal expansion coefficient mismatch between the substrate 33a and the circuit board 32a is reduced. deformation mismatch.
  • this embodiment reduces the substrate deformation force generated by the deformation of the substrate 33a on the circuit board 32a, further reduces the non-self-deformation of the circuit board 32a, and eliminates or reduces soldering.
  • the point 36a is subjected to downward structural deformation stress, thereby increasing the thermal cycle fatigue life of the solder joint 36a and increasing the service life of the circuit board assembly 3a.
  • FIG. 5 is a schematic diagram of a modification of the circuit board assembly 3 shown in FIG. 2A in still other embodiments provided in the present application.
  • most of the structure of the circuit board assembly 3b is the same as that in the first embodiment, and will not be repeated here.
  • the substrate 33b may include a first backplane 331 and a second backplane 332 that are stacked and fixedly connected.
  • the second backplane 332 is located on the side of the first backplane 331 facing away from the circuit board 32b.
  • the thermal expansion coefficient of the first back plate 331 may be smaller than that of the second back plate 332 .
  • the first back plate 331 may be a pre-galvanized steel plate
  • the second back plate 332 may be an aluminum alloy steel plate.
  • the first backplane 331 and the second backplane 332 can also be made of other materials, as long as the thermal expansion coefficient of the first backplane 331 can be smaller than the thermal expansion coefficient of the second backplane 332 . The example does not limit this.
  • FIG. 6 is a schematic diagram of the deformation of the substrate 33 b shown in FIG. 5 .
  • the substrate 33b adopts a double-layer structure, that is, the substrate 33b includes a first backplane 331 and a second backplane 332 which are arranged in layers.
  • the thermal expansion coefficient of the first back plate 331 is smaller than the thermal expansion coefficient of the second back plate 332 , so that the thermal deformation amount of the first back plate 331 is smaller than that of the second back plate 332 .
  • the substrate 33b will protrude toward the side where the second backplane 332 with a large amount of deformation is located, that is, both ends of the substrate 33b will be lifted upward to match the deformation mode of the circuit board 32b. Therefore, in this embodiment, when the temperature of the circuit board 32b, the substrate 33b and other structures changes relative to the normal temperature, the protruding direction of the substrate 33b is the same as the protruding direction of the circuit board 32b, so as to prevent the circuit board 32b from being affected by The influence of the substrate deformation force produces a non-self-deformation that maintains the deformation of the circuit board 32b in the bare state. At the same time, the solder joints 36b will not be subjected to downward structural deformation stress, thereby improving the thermal cycle fatigue life of the solder joints 36b and the service life of the circuit board assembly 3b.
  • the substrate 33b may also adopt a structure of more than two layers, for example, three layers, etc., which is not limited in this embodiment of the present application, as long as it satisfies that when the temperature at the substrate 33b changes relative to the normal temperature, more The thermal expansion coefficient of the layer structure increases as the distance from the circuit board 32b increases, and the protruding direction of the substrate 33b may be the same as the protruding direction of the circuit board 32b.
  • the thermal expansion coefficient of the substrate 33b may or may not be close to that of the circuit board 32b, that is, the difference between the second thermal expansion coefficient and the first thermal expansion coefficient may be greater than 30% of the first coefficient of thermal expansion to further reduce the influence of substrate deformation forces.
  • the thermal expansion coefficient of the substrate 33b is the total thermal expansion coefficient of the fixed structure composed of the first backplane 331 and the second backplane 332 .
  • FIG. 7 is a schematic structural diagram of the circuit board assembly 3 shown in FIG. 2A in still other embodiments provided in this application.
  • the circuit board assembly 3c may include buffer members 37c, such as a first buffer member 371 and a second buffer member 372, for reducing the connection effect of the fixing member 34c on the circuit board 32c and the substrate 33c.
  • the first buffer member 371 and the second buffer member 372 may be disposed on the lower side and the upper side of the circuit board 32c, respectively.
  • the first buffer member 371 may be located on the upper side of the circuit board 32c, that is, on the side of the circuit board 32c facing away from the substrate 33c and contact the circuit board 32c, and the fixing member 34c is inserted into the first buffer member 371.
  • the fixing member 34c may include a limiting member 341 and a plug-in member 341, the position-limiting member 341 protrudes outwardly relative to the peripheral side of the plug-in member 341, and the first buffer member 371 is located between the position-limiting member 341 and the circuit board 32c and contacts the circuit board 32c.
  • the limiting member 341 and the circuit board 32c may be located on the upper side of the circuit board 32c, that is, on the side of the circuit board 32c facing away from the substrate 33c and contact the circuit board 32c, and the fixing member 34c is inserted into the first buffer member 371.
  • the fixing member 34c may include a limiting member 341 and a plug-in member 341, the position-limiting member 341 protrudes outwardly
  • the second buffer member 372 is located on the lower side of the circuit board 32c, that is, between the circuit board 32c and the substrate 33c and contacts the circuit board 32c and the substrate 33c, and the fixing member 34c is inserted into the second buffer member 372.
  • FIG. 8 is a schematic diagram of a deformation of the circuit board assembly 3 c shown in FIG. 7 .
  • the first buffer member 371 is deformed to reduce the connection between the fixing member 34c and the circuit board 32c.
  • the deformation space of the circuit board 32c in the horizontal direction X is increased to prevent the deformation of the circuit board 32c from being restricted by the fixing member 34c.
  • the second buffer member 372 is deformed to reduce the connection between the circuit board 32c and the substrate 33c, increase the deformation space of the circuit board 32c and the substrate 33c in the horizontal direction X, and prevent the deformation of the circuit board 32c from being affected by the backing The effect of the bottom deformation force.
  • the first buffer member 371 and the second buffer member 372 can reduce the connection effect of the fixing member 34c on the circuit board 32c and the substrate 33c, and increase the circuit board while ensuring the fastening function of the fixing member 34c.
  • the deformation space of 32c and the substrate 33c in the horizontal direction X avoids the non-self-deformation of the circuit board 32c, maintains the deformation of the circuit board 32c when it is in a bare board state, and at the same time can prevent the solder joint 36c from being subjected to structural deformation stress, improving the solder joint.
  • the buffer member 37c can also be provided on the upper side or the lower side of the circuit board 32c to reduce the volume of the circuit board 32c and its related components and make the structure of the circuit board component 3c more compact, which is not limited in this application.
  • the circuit board assembly 3c may not be provided with the fixing member 34c, and the circuit board 32c and the substrate 33c are fixedly connected through an intermediate buffer member (not shown), that is, the circuit board 32c and the substrate 33c may be fixedly connected.
  • An intermediate buffer member is provided, and two sides of the intermediate buffer member are respectively fixedly connected to the circuit board 32c and the substrate 33c.
  • the intermediate buffer member can be deformed by force, and the deformation performance of the intermediate buffer member can reduce the connection between the circuit board 32c and the substrate 33c, offset the difference in deformation between the circuit board 32c and the substrate 33c, and avoid the circuit board 32c and the substrate 33c.
  • the deformation of the circuit board 32c is affected by the deformation force of the substrate, and the deformation of the circuit board 32c in the bare state is maintained, so as to improve the thermal cycle fatigue life of the solder joint 36c.
  • the buffer member 37c can be made of elastic materials such as rubber, foam, PTFE (poly tetrafluoroethylene, polytetrafluoroethylene), etc., or a structure that can elastically deform under force such as a spring.
  • the buffer member 37c may adopt a bionic design structure, so as to better match the deformed shape of the circuit board 32c and increase the fastening effect of the fixing member 34c on the circuit board 32c and the substrate 33c.
  • the substrate 33c may adopt a single-layer structure, or a double-layer or more than two-layer structure, and the circuit board 32c is kept in a bare state by the deformation matching of the buffer member 37c and the substrate 33c.
  • the deformation of the solder joint 36c increases the thermal cycle fatigue life of the solder joint 36c.
  • the thermal expansion coefficient of the substrate 33c can be close to that of the circuit board 32c, so as to reduce the difference in deformation between the substrate 33c and the circuit board 32c and increase the temperature of the solder joints 36c. Cycle fatigue life.
  • the thermal expansion coefficient of the substrate 33c may not be close to the thermal expansion coefficient of the circuit board 32c, which is not limited in this embodiment.
  • FIG. 9 is a schematic structural diagram of the circuit board assembly 3 shown in FIG. 2A in still other embodiments provided in the present application.
  • most of the structure of the circuit board assembly 3d is the same as that in the first embodiment, and will not be repeated here.
  • the circuit board assembly 3d may include a bracket 38d, the bracket 38d is located on the side of the circuit board 32d facing away from the substrate 33d, and both ends of the bracket 38d may be fixed to both ends of the circuit board 32d by the fixing member 34d. connect.
  • a gap is formed between the middle portion of the bracket 38d and the middle portion of the circuit board 32d.
  • the thermal expansion coefficient of the bracket 38d may be smaller than that of the circuit board 32d, so that when the bracket 38d, the circuit board 32d and the substrate 33d are heated, the deformation of the bracket 38d is smaller than that of the circuit board 32d.
  • FIG. 10 is a schematic diagram of a deformation of the circuit board assembly 3d shown in FIG. 9 .
  • the deformation amount of the bracket 38d is smaller than that of the circuit board 32d, so that the effect on both ends of the circuit board 32d can be exerted. It can counteract the substrate deformation force generated by the deformation of the substrate 33d on the circuit board 32d, avoid the non-self-deformation of the circuit board 32d, maintain the deformation of the circuit board 32d when it is in a bare state, and prevent the solder joint 36d from being subjected to downward pressure.
  • the deformation stress of the structure is improved, and the temperature cycle fatigue life of the solder joint 36d and the service life of the circuit board assembly 3d are improved.
  • FIG. 11 is a schematic diagram of a modification of the circuit board assembly 3 shown in FIG. 2A in some embodiments provided in the present application.
  • the bracket 38e may include an upper bracket 381 and a lower bracket 382 that are stacked and fixedly connected, and the upper bracket 381 is located on the side of the lower bracket 382 facing away from the circuit board 32e. Both ends of at least one of the upper bracket 381 and the lower bracket 382 are fixedly connected to the circuit board 32e, and a gap is formed between the middle part of the lower bracket 382 and the middle part of the circuit board 32e.
  • the thermal expansion coefficient of the upper bracket 381 may be smaller than the thermal expansion coefficient of the lower bracket 382 , so that the thermal deformation amount of the upper bracket 381 is smaller than that of the lower bracket 381 .
  • the bracket 38e will protrude toward the side where the lower bracket 381 with a large deformation amount is located, that is, both ends of the bracket 38e will be lifted upward to match the deformation mode of the circuit board 32e.
  • the bracket 38e when the temperature of the circuit board 32e, the substrate 33e, the bracket 38e and other structures changes relative to the normal temperature, the bracket 38e will exert upward force on both ends of the circuit board 32e to offset the The deformation of the substrate 33e exerts an oblique downward substrate deformation force on the circuit board 32e, and maintains the deformation of the circuit board 32e when the circuit board 32e is in a bare state.
  • the solder joint 36e will not be subjected to downward structural deformation stress, thereby improving the thermal cycle fatigue life of the solder joint 36e.
  • the upper bracket 381 may be a pre-galvanized steel plate, and the lower bracket 382 may be an aluminum alloy steel plate.
  • the upper bracket 381 and the lower bracket 382 can also be made of other materials, as long as the thermal expansion coefficient of the upper bracket 381 can be smaller than that of the lower bracket 382 , which is not made in this embodiment of the present application. limited.
  • the bracket 38e may adopt a double-layer structure, that is, it includes an upper bracket 381 and a lower bracket 382 arranged in layers.
  • the bracket 38e can also adopt a structure of more than two layers, for example, three layers, etc., which is not limited in this embodiment of the present application, as long as it satisfies that when the temperature at the bracket 38e changes relative to the normal temperature, more The thermal expansion coefficient of the layered structure decreases as the distance between the multilayered structure and the circuit board 32e increases, so that the protruding direction of the bracket 38e is the same as the protruding direction of the circuit board 32e.
  • the total deformation amount of the single-layer or multi-layer bracket 38e can be consistent with the deformation amount of the circuit board 32e.
  • the additional deformation force is applied to maintain the deformation of the circuit board 32e when the circuit board 32e is in the bare state, and further improve the thermal cycle fatigue life of the solder joint 36e.
  • the circuit board assembly (3d, 3e) may not include the fixing member (34d, 34e), the bracket Both ends of (38d, 38e) can also be fixedly connected to both ends of the circuit board (32d, 32e) by welding, gluing, etc., and the middle of the circuit board (32d, 32e)
  • the middle movement is not limited in this application.
  • the thermal expansion coefficient of the substrate (33d, 33e) may or may not be close to that of the circuit board (32d, 32e).
  • the substrates (33d, 33e) of the circuit board assemblies (3d, 3e) may also adopt a structure of two layers or more, and the substrates (33d, 33d) , 33e) and the brackets (38d, 38e) counteract the deformation force of the substrate, so that the circuit board (32d, 32e) is deformed when it is in a bare state, and the temperature of the solder joints (36d, 36e) is increased. Cycle fatigue life.
  • the substrates (33d, 33e) of the circuit board assemblies (3d, 3e) may also adopt a structure of two layers or more, and the substrates (33d, 33d) , 33e) and the brackets (38d, 38e) counteract the deformation force of the substrate, so that the circuit board (32d, 32e) is deformed when it is in a bare state, and the temperature of the solder joints (36d, 36e) is increased. Cycle fatigue life.
  • the second embodiment which will not be repeated here.
  • the circuit board assembly (3d, 3e) may further include a buffer (not shown), and the buffer may be disposed between the brackets (38d, 38e) and the Between the circuit boards (32d, 32e) and/or between the circuit boards (32d, 32e) and the substrate (33d, 33e), the counteracting effect on the deformation force of the substrate through the buffer and the bracket (38d, 38e) , to deform the circuit boards (32d, 32e) when they are in a bare-board state, and to improve the thermal cycle fatigue life of the solder joints (36d, 36e).
  • the buffer member For the specific arrangement and structure of the buffer member, reference may be made to the third embodiment, which will not be repeated here.
  • the fixing members (34d, 34e) can be inserted into two ends of the brackets (38d, 38e), that is, the upper parts of the brackets (38d, 38e).
  • the surface contacts or abuts the limiting members (341d, 341e) of the fixing members (34d, 34e), and the buffer member may be located between the bracket (38d, 38e) and the circuit board (32d, 32e).
  • the assembly steps of the circuit board assembly 3 are as follows:
  • the second buffer member 372 may be disposed opposite to the first buffer member 371;
  • bracket 38d above the circuit board 32 or the second buffer member 372 .
  • the circuit board assembly 3 may also not include the first buffer member 371.
  • the assembly steps of the circuit board assembly 3 are as follows:
  • the second buffer member 372 may be disposed opposite to the first buffer member 371;
  • bracket 38d above the circuit board 32 or the second buffer member 372 .

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Abstract

本申请公开一种电路板组件及电子设备。电路板组件应用于电子设备，电路板组件包括搭载大尺寸芯片的电路板以及衬底。衬底设置于电路板背向芯片的一侧、且与电路板连接。本申请通过对电路板组件的变形方式进行设计，有效降低衬底变形产生的应力对电路板自有变形的影响，提升芯片与电路板之间焊点的长期温循疲劳寿命。

Description

电路板组件及电子设备
本申请要求于2021年04月27日提交中国专利局、申请号为202110457497.X、申请名称为“电路板组件及电子设备”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及电子产品技术领域，尤其涉及一种电路板组件及电子设备。
背景技术
搭载大尺寸芯片的电路板背向芯片的一侧设有衬底，以提升电路板的机械强度，从而增强对芯片的防护和固定作用。但是，由于衬底与电路板的热膨胀系数不同，导致当衬底与电路板等结构处温度相对于常温发生变化时，衬底与电路板产生的变形量不同，使得电路板在衬底变形的影响下产生非自有变形，因此，电路板与芯片之间的焊点受到额外的结构变形应力，降低了焊点的温循疲劳寿命，导致电路板组件的使用寿命缩短。
发明内容
本申请公开一种电路板组件及电子设备，电路板组件应用于电子设备，电子设备具有较长的使用寿命。电路板组件包括搭载大尺寸芯片的电路板以及衬底。衬底设置于电路板背向芯片的一侧、且与电路板连接。本申请通过对电路板组件的变形方式进行设计，有效降低衬底变形产生的作用力对电路板自有变形的影响，提升芯片与电路板之间焊点的长期温循疲劳寿命。
第一方面，本申请提供一种电路板组件，其特征在于，包括电路板和固定于电路板一侧的衬底，电路板具有第一热膨胀系数，衬底具有第二热膨胀系数，第二热膨胀系数与第一热膨胀系数的差值小于或等于第一热膨胀系数的30％。
在本申请中，衬底与电路板热膨胀系数接近，使得在电路板、衬底等结构处的温度相对于常温发生变化时，衬底和电路板的变形量接近，避免电路板受衬底变形作用力的影响产生非自有变形，保持电路板处于裸板状态时的变形。同时，焊点不会受到向下的结构变形应力，提高焊点的温循疲劳寿命。
示例性的，电路板一般采用树脂来实现绝缘功能。树脂的热膨胀系数较高，也即电路板的热膨胀系数较高。传统方案中，为了保证衬底对电路板的防护作用，衬底一般采用金属和陶瓷等机械强度较高的材料，例如不锈钢、铝合金等，也即衬底的热膨胀系数较低。可理解地，机械强度高的材料的热膨胀系数一般较低。当电路板和衬底处的温度相对于常温发生变化时，热膨胀系数较高的电路板的变形量大于热膨胀系数较低的衬底的变形量，导致衬底与电路板之间因热膨胀系数失配产生变形量失配。
在本实现方式中的衬底与电路板热膨胀系数接近，虽然牺牲了一部分机械强度，减弱了衬底的防护作用，但降低了衬底与电路板之间因热膨胀系数失配产生的变形量失配。本实施例与现有技术相比，减小了衬底变形对电路板产生的衬底变形作用力，并进一步减小了电路板产生的非自有变形，消除或减小了焊点受到向下的结构变形应力，从而提升焊点的温循疲 劳寿命，并增加电路板组件的使用寿命。
一种可能的实现方式中，衬底包括第一背板和第二背板，第二背板位于第一背板背向电路板的一侧，第一背板的热膨胀系数小于第二背板的热膨胀系数，第一背板和第二背板中的至少一者固定连接电路板。
在本实现方式中，第一背板的热膨胀系数小于第二背板的热膨胀系数，使得第一背板的热变形量小于第二背板的热变形量。衬底会向变形量大的第二背板所在的一侧凸起，也即衬底的两端向上翘起，以匹配电路板的变形方式。因此，当电路板、衬底等结构处的温度相对于常温发生变化时，衬底的凸起方向与电路板的凸起方向相同，避免电路板受衬底变形作用力的影响产生非自有变形，保持电路板处于裸板状态时的变形。同时，焊点不会受到向下的结构变形应力，提高焊点的温循疲劳寿命和电路板组件的使用寿命。
在本实现方式中，衬底的热膨胀系数可以与电路板的热膨胀系数接近，也即第二热膨胀系数与第一热膨胀系数之间的差值可以大于第一热膨胀系数的30％，以进一步减小衬底变形作用力的影响。衬底的热膨胀系数为第一背板和第二背板组成的固定结构的总的热膨胀系数。
一种可能的实现方式中，电路板组件还包括中间缓冲件，中间缓冲件的相背两侧分别固定连接电路板和衬底，中间缓冲件能够在外力作用下产生弹性形变。
在本实现方式中，中间缓冲件受力能够发生形变，利用中间缓冲件的变形性能，可以减少电路板和衬底之间的连接作用，抵消电路板和衬底之间的变形量差异，避免电路板的变形受到衬底变形作用力的影响，保持电路板处于裸板状态时的变形，以提高焊点的温循疲劳寿命。
一种可能的实现方式中，电路板组件还包括：
固定件，电路板与衬底堆叠设置且两者之间形成间隙，固定件设于电路板两端，固定件插接电路板、且固定连接衬底，电路板组件受热时，电路板与衬底的相对位置发生变化；
第一缓冲件，第一缓冲件位于电路板背向衬底的一侧且接触电路板，固定件插接第一缓冲件，电路板组件受热时，第一缓冲件发生形变；
和/或第二缓冲件，第二缓冲件位于电路板与衬底之间且接触电路板及衬底，固定件插接第二缓冲件，电路板组件受热时，第二缓冲件发生形变。
在本实现方式中，电路板组件受热时，电路板与衬底的相对位置发生变化，第一缓冲件发生形变，以减小固定件和电路板之间的连接作用，增大电路板在水平方向上的变形空间，避免电路板的变形受到固定件的限制。第二缓冲件发生形变，以减小电路板和衬底之间的连接作用，增大电路板和衬底在水平方向上的变形空间，避免电路板的变形受到衬底变形作用力的影响。
第一缓冲件和第二缓冲件可以减小固定件对电路板和衬底的连接作用，在保证固定件的紧固作用的同时、增加电路板和衬底在水平方向上的变形空间，避免电路板产生非自有变形，保持电路板处于裸板状态时的变形，同时能够进一步避免焊点受到结构变形应力，提高焊点的温循疲劳寿命和电路板组件的使用寿命。
示例性的，缓冲件也可以设于电路板的上侧或下侧，减小电路板及其相关组件的体积，使得电路板组件的结构更加紧凑，本申请对此不作限定。
一种可能的实现方式中，电路板组件还包括托架，托架位于电路板背向衬底的一侧、且托架的两端与电路板的两端固定连接，托架的中部与电路板的中部之间形成间隙，托架的热膨胀系数小于电路板的热膨胀系数。
在本实现方式中，当电路板、衬底、托架等结构处的温度相对于常温发生变化时，托架 的变形量小于电路板的变形量，从而能够对电路板的两端施加向上的作用力，抵消衬底变形对电路板产生的斜向下的衬底变形作用力，避免电路板产生非自有变形，并保持电路板处于裸板状态时的变形，同时能够避免焊点受到向下的结构变形应力，提高焊点的温循疲劳寿命和电路板组件的使用寿命。
一种可能的实现方式中，托架包括层叠设置且固定连接的上托架和下托架，上托架位于下托架背向电路板的一侧，上托架和下托架中的至少一者的两端固定连接电路板，下托架的中部与电路板的中部之间形成间隙，上托架的热膨胀系数小于下托架的热膨胀系数。
在本实现方式中，当电路板、衬底、托架等结构处的温度相对于常温发生变化时，托架会对电路板的两端施加向上的作用力，以进一步抵消衬底变形对电路板产生的斜向下的衬底变形作用力，保持电路板处于裸板状态时的变形。同时，焊点不会受到向下的结构变形应力，提高焊点的温循疲劳寿命。
第二方面，本申请还提供一种电路板组件，包括电路板和与电路板固定连接的衬底，衬底包括第一背板和第二背板，第二背板位于第一背板背向电路板的一侧，第一背板的热膨胀系数小于第二背板的热膨胀系数，第一背板和第二背板中的至少一者固定连接电路板。
在本实现方式中，通过衬底的变形匹配对衬底变形作用力的抵消作用，保持电路板处于裸板状态时的变形，提升焊点的温循疲劳寿命。示例性的，第一背板可以是预镀锌钢板，第二背板可以是铝合金钢板。在其他一些实现方式中，第一背板和第二背板也可以采用其他材料，只要保证第一背板的热膨胀系数可以小于第二背板的热膨胀系数即可，本申请对此不作限定。
在其他一些实现方式中，衬底也可以采用双层以上结构，例如，三层等，本申请对此不作限定，只要满足当衬底处的温度相对于常温发生变化时，多层结构的热膨胀系数随与电路板的距离的增大而增大，衬底的凸起方向与电路板的凸起方向相同即可。
一种可能的实现方式中，电路板组件还包括中间缓冲件，中间缓冲件的相背两侧分别固定连接电路板和衬底，中间缓冲件能够在外力作用下产生弹性形变。
一种可能的实现方式中，电路板组件还包括：
固定件，电路板与衬底堆叠设置且两者之间形成间隙，固定件设于电路板两端，插接电路板、且固定连接衬底，电路板组件受热时，电路板与衬底的相对位置发生变化；
第一缓冲件，第一缓冲件位于电路板背向衬底的一侧且接触电路板，固定件插接第一缓冲件，电路板组件受热时，第一缓冲件发生形变；
和/或第二缓冲件，第二缓冲件位于电路板与衬底之间且接触电路板及衬底，固定件插接第二缓冲件，电路板组件受热时，第二缓冲件发生形变。
一种可能的实现方式中，电路板组件还包括托架，托架位于电路板背向衬底的一侧、且托架的两端与电路板的两端固定连接，托架的中部与电路板的中部之间形成间隙，托架的热膨胀系数小于电路板的热膨胀系数。
一种可能的实现方式中，托架包括层叠设置且固定连接的上托架和下托架，上托架位于下托架背向电路板的一侧，上托架和下托架中的至少一者的两端固定连接电路板，下托架的中部与电路板的中部之间形成间隙，上托架的热膨胀系数小于下托架的热膨胀系数。
第三方面，本申请又提供一种电路板组件，包括电路板、衬底及固定件，电路板与衬底堆叠设置且两者之间形成间隙，固定件设于电路板两端，固定件插接电路板、且固定连接衬底，电路板组件受热时，电路板与衬底的相对位置发生变化；
电路板组件还包括：
第一缓冲件，第一缓冲件位于电路板背向衬底的一侧且接触电路板，固定件插接第一缓冲件，电路板组件受热时，第一缓冲件发生形变；
和/或第二缓冲件，第二缓冲件位于电路板与衬底之间且接触电路板及衬底，固定件插接第二缓冲件，电路板组件受热时，第二缓冲件发生形变。
一种可能的实现方式中，第一缓冲件采用泡棉、橡胶或弹簧，和/或第二缓冲件采用泡棉、橡胶、PTFE或弹簧。
在本实现方式中，通过缓冲件对衬底变形作用力的抵消作用，保持电路板处于裸板状态时的变形，提升焊点的温循疲劳寿命。示例性的，缓冲件可以采用橡胶、泡棉、PTFE(poly tetra fluoroethylene，聚四氟乙烯)等弹性材料，也可以采用弹簧等受力可以发生弹性变形的结构。缓冲件可以采用仿生设计结构，以便更好地匹配电路板变形后的形状、并增加固定件对电路板和衬底的紧固效果。
一种可能的实现方式中，固定件包括固定连接的限位件和插接件，限位件相对插接件的周侧向外凸起，第一缓冲件位于限位件和电路板之间且接触限位件及电路板。
一种可能的实现方式中，电路板组件还包括托架，托架位于电路板背向衬底的一侧、且托架的两端与电路板的两端固定连接，托架的中部与电路板的中部之间形成间隙，托架的热膨胀系数小于电路板的热膨胀系数。
一种可能的实现方式中，托架包括层叠设置且固定连接的上托架和下托架，上托架位于下托架背向电路板的一侧，上托架和下托架中的至少一者的两端固定连接电路板，下托架的中部与电路板的中部之间形成间隙，上托架的热膨胀系数小于下托架的热膨胀系数。
示例性的，上托架可以是预镀锌钢板，下托架可以是铝合金钢板。在其他一些实现方式中，上托架和下托架也可以采用其他材料，只要保证上托架的热膨胀系数可以小于下托架的热膨胀系数即可，本申请对此不作限定。
在本实现方式中，托架可以采用双层结构，也即包括层叠设置的上托架和下托架。在其他一些实现方式中，托架也可以采用双层以上结构，例如，三层等，本申请对此不作限定，只要满足当托架处的温度相对于常温发生变化时，多层结构的热膨胀系数随多层结构与电路板的距离的增大而减小，使得托架的凸起方向与电路板的凸起方向相同即可。
第四方面，本申请再提供一种电路板组件，包括电路板、衬底和托架，衬底与电路板固定连接，托架位于电路板背向衬底的一侧、且托架的两端与电路板的两端固定连接，托架的中部与电路板的中部之间形成间隙，托架的热膨胀系数小于电路板的热膨胀系数。
在本实现方式中，通过托架对衬底变形作用力的抵消作用，保持电路板处于裸板状态时的变形，提升焊点的温循疲劳寿命。
一种可能的实现方式中，托架包括层叠设置且固定连接的上托架和下托架，上托架位于下托架背向电路板的一侧，上托架和下托架中的至少一者的两端固定连接电路板，下托架的中部与电路板的中部之间形成间隙，上托架的热膨胀系数小于下托架的热膨胀系数。
第五方面，本申请提供一种电子设备，包括上述电路板组件，电路板组件包括芯片，芯片固定于电路板背向衬底的一侧，电子设备具有较长的使用寿命。
附图说明
图1是本申请提供的电子设备在一些实施例中的部分结构示意图；
图2A是图1所示电路板组件在一些实施例中的结构示意图；
图2B是图1所示电路板组件在其他一些实施例中的结构示意图；
图3A是裸板状态的电路板组件的变形示意图；
图3B是采用传统结构的电路板组件的变形示意图；
图4是图2A所示电路板组件在本申请提供的一些实施例中的变形示意图；
图5是图2A所示电路板组件在本申请提供的又一些实施例中的变形示意图；
图6是图5所示衬底的变形示意图；
图7是图2A所示电路板组件在本申请提供的再一些实施例中的结构示意图；
图8是图7所示电路板组件的变形示意图；
图9是图2A所示电路板组件在本申请提供的还一些实施例中的结构示意图；
图10是图9所示电路板组件的变形示意图；
图11是图2A所示电路板组件在本申请提供的多一些实施例中的变形示意图。
具体实施方式
下面结合本申请实施例中的附图对本申请实施例进行描述。其中，本文中的“和/或”仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。此外，在本申请实施例的描述中，除非另有说明，“多个”是指两个或多于两个。“以上”包括本数，例如，两个以上包括两个。
请参阅图1，图1是本申请提供的电子设备100在一些实施例中的部分结构示意图。电子设备100可以是应用于信号的传送、接入、计算，以及无线通讯等领域的电子产品，例如，服务器、路由器、手机、笔记本电脑、电视机、智能家居设备、车载设备等。
示例性的，电子设备100可以包括中空的壳体1和天线2。天线2可以用于接收和发射信号，通过电磁波实现信号的无线传输。天线2可以固定于壳体1的外侧，也可以安装于壳体1的内部。在其他一些实施例中，电子设备100也可以不包括天线2，而采用光纤、线缆等其他信号传输方式，本申请对此不作限定。
示例性的，壳体1可以包括壳体内腔，用于容置电子设备100的内部结构。电子设备100还可以包括安装于壳体内腔的电路板组件3。
示例性的，电子设备100还可以包括与电路板组件3固定连接的散热器(图未示)。散热器可以是由铝合金，黄铜或青铜做成的板状，片状，多片状等结构，用于将电路板组件3的热量散发出去，以降低电路板组件3的温度，保障电路板组件3的运行稳定性并提高其使用寿命。
请参阅图2A，图2A是图1所示电路板组件3在一些实施例中的结构示意图。示例性的，电路板组件3可以包括芯片31、电路板32、衬底33及固定件34。
电路板32与衬底33固定连接、且电路板32的下表面可以贴合衬底33的上表面。可以理解地，在本申请中，两个部件可以通过连接件固定连接。两个部件固定连接也即两个部件的位置关系不变，但允许由于两个部件之间的连接件的形变所导致的位置关系变化。此外，本申请中涉及的“上”、“下”、“内”、“外”等方位用词，是参考附加图式的方位进行的描述，并不是指示或暗指所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本申请的限制。
示例性的，电路板32和衬底33可以通过固定件34固定连接，固定件34设于电路板32两端。固定件34插接电路板32、且固定连接衬底33。电路板32与衬底33堆叠设置且两者之间形成间隙，当电路板组件3受热时，电路板32与衬底33的相对位置发生变化。固定件34可以是螺钉、铆钉等紧固件。在其他一些实施例中，电路板32也可以通过胶接、焊接等 方式与衬底33固定连接。
示例性的，当固定件34为螺钉时，衬底33可以包括开口朝向电路板32的螺孔(图未示)，螺孔内壁设有与螺钉周侧螺纹相配合的内螺纹。螺钉可以伸入螺孔，并通过与螺孔紧固配合，以实现与衬底33固定连接。
示例性的，芯片31固定于电路板32背向衬底33的一侧且与其电连接。芯片31可以用于实现信号的传输，也可以对信号进行处理。
示例性的，芯片31可以是大尺寸ASIC(application specific integrated circuit，供专门应用的集成电路)芯片，能够根据产品的需求进行特定设计和制造以实现特定功能的强化，具有较高的处理速度和低能耗。芯片31也可以是CPU(central processing unit，中央处理单元)、GPU(graphics processing unit，图像处理单元)等通用型芯片或FPGA(field programmable gate array，现场可编程门阵列)等半定制芯片，本申请实施例对此不做限定。
示例性的，芯片31可以通过焊点与电路板32实现固定连接和电连接。例如，芯片31可以采用BGA(ball grid array package，球栅阵列封装)的方式与电路板32连接，也可以采用SMT(surface mounted technology，表面贴装技术)等方式与电路板32连接。在其他一些实施例中，芯片31也可以采用导电胶等方式与电路板32固定连接和电连接，本申请对芯片31与电路板32的连接方式不作限定。
在本申请中，电子设备100采用大尺寸的ASIC芯片，以满足大功率的使用要求，同时也产生较大的热量，使得电路板32和衬底33受热产生热应变。
示例性的，本申请以芯片31采用BGA的方式与电路板32连接为例进行说明。电路板组件3还可以包括多个焊点(图未示)，焊点设置在芯片31与电路板32之间，并与芯片31和电路板32固定连接，以实现芯片31与电路板32的固定连接和电连接。
在本申请中，水平方向X为平行于未变形时的电路板32上表面所在平面的方向。示例性的，水平方向X可以是平行于未变形时的电路板32上表面所在平面的任意方向，本申请实施例对此不作限定。
请参阅图2B，图2B是图1所示电路板组件3在其他一些实施例中的结构示意图。示例性的，电路板组件3也可以包括支撑件35，支撑件35可以固定于衬底33面向电路板32的一侧、且相对衬底33的上表面凸起。此时，电路板32的下表面与衬底33的上表面之间存在间隙，为电路板32的变形留有充足的空间。支撑件35可以接触或抵持在电路板32背向芯片31的下表面，固定件34穿过电路板32与支撑件35固定连接。
示例性的，当固定件34为螺钉时，支撑件35可以是与螺钉配套的螺母，螺钉穿过电路板32与螺母锁紧。螺母可以固定于衬底33面向电路板32的一侧、且接触或抵持在电路板32的下表面。
请参阅图3A，图3A是裸板状态的电路板组件4的变形示意图，其中图3A中的局部放大图展示了焊点41的受力示意图。
在本申请中，裸板状态的电路板组件4包括电路板42、焊接于电路板42的芯片43及电路板42与芯片43之间的焊点41，裸板状态的电路板组件4不在电路板42背向芯片43一侧设置衬底。
示例性的，电路板42一般用于承载电子元件并实现电子元件之间的电连接。当裸板状态的电路板组件4处的温度相对于常温发生变化时，电路板组件4会发生变形。具体地，当芯片43和电路板42处的温度相对于常温升高，也即芯片43和电路板42处于高温时，电路板42和芯片43会产生变形，中间下凹，两端翘起，呈现“笑脸”形。当芯片43和电路板42 处的温度相对于常温降低，也即芯片43和电路板42处于低温时，电路板42和芯片43会中间凸起，呈现“哭脸”形。而且，电路板42的变形量大于芯片43的变形量。焊点41的上端和下端分别固定连接芯片43和电路板42，芯片43和电路板42的变形量失配使得焊点41的上端和下端分别受到水平方向X上的、且方向相反的剪切力。
此外，当芯片43和电路板42处的温度回到常温，电路板42会从变形状态恢复至未发生变形的状态；当芯片43和电路板42处的温度相对于常温发生变化时，电路板42会再次发生变形，对焊点41产生剪切力，如此循环进行，使得焊点41产生温循疲劳。
在本申请中，电路板组件4处的温度在20℃至30℃的范围内即可认为是常温，温度在常温至200℃的范围内即可认为是高温，温度在零下100℃至常温的范围内即可认为是低温。
请参阅图3B，图3B是采用传统结构的电路板组件5的变形示意图，其中图3B中的局部放大图展示了焊点51的受力示意图。
在本申请中，采用传统结构的电路板组件5包括芯片53、电路板54、衬底55、固定件52和焊点51。其中，芯片53焊接于电路板54，焊点位于电路板54与芯片53之间。固定件52设于电路板54两端。固定件52插接电路板54、且固定连接衬底55。
与处于裸板状态时的电路板组件5的变形方式不同，当电路板54的两端和衬底55通过固定件52固定连接时，衬底55会通过固定件52的连接作用对电路板54产生斜向下的衬底变形作用力，导致电路板54受热时的变形方式发生变化，产生非自有变形。具体地，电路板54的两端受到衬底变形作用力，向下弯曲，呈现“M”形，使得焊点51在受到水平方向X的剪切力的同时，还受到向下的结构变形应力，导致焊点51出现裂纹的概率增大，显著降低焊点51的温循疲劳寿命。
请参阅图4，图4是图2A所示电路板组件3在本申请提供的一些实施例中的变形示意图。在第一实施例中，电路板32a可以具有第一热膨胀系数(coefficient of thermal epansion，CTE)，衬底33a可以具有第二热膨胀系数。第二热膨胀系数可以与第一热膨胀系数接近，也即，第二热膨胀系数与第一热膨胀系数之间的差值小于或等于第一热膨胀系数的30％。示例性的，第二热膨胀系数可以等于第一热膨胀系数，第二热膨胀系数与第一热膨胀系数之间的差值也可以是第一热膨胀系数的1％、5％或15％等，本实施例对此不作限定。
请一并参阅图3B和图4，在本申请中，衬底33a与电路板32a热膨胀系数接近，使得在电路板32a、衬底33a等结构处的温度相对于常温发生变化时，衬底33a和电路板32a的变形量接近，避免电路板32a受衬底变形作用力的影响产生非自有变形，保持电路板32a处于裸板状态时的变形。同时，焊点36a不会受到向下的结构变形应力，提高焊点36a的温循疲劳寿命。
示例性的，电路板32a一般采用树脂来实现绝缘功能。树脂的热膨胀系数较高，也即电路板32a的热膨胀系数较高。传统方案中，为了保证衬底33a对电路板32a的防护作用，衬底33a一般采用金属和陶瓷等机械强度较高的材料，例如不锈钢、铝合金等，也即衬底33a的热膨胀系数较低。可理解地，机械强度高的材料的热膨胀系数一般较低。当电路板32a和衬底33a处的温度相对于常温发生变化时，热膨胀系数较高的电路板32a的变形量大于热膨胀系数较低的衬底33a的变形量，导致衬底33a与电路板32a之间因热膨胀系数失配产生变形量失配。
本实施例中的衬底33a与电路板32a热膨胀系数接近，虽然牺牲了一部分机械强度，减弱了衬底33a的防护作用，但降低了衬底33a与电路板32a之间因热膨胀系数失配产生的变形量失配。本实施例与现有技术相比，减小了衬底33a变形对电路板32a产生的衬底变形作 用力，并进一步减小了电路板32a产生的非自有变形，消除或减小了焊点36a受到向下的结构变形应力，从而提升焊点36a的温循疲劳寿命，并增加电路板组件3a的使用寿命。
请参阅图5，图5是图2A所示电路板组件3在本申请提供的又一些实施例中的变形示意图。在第二实施例中，电路板组件3b的大部分结构与第一实施例中相同，在此不再赘述。
示例性的，衬底33b可以包括层叠设置且固定连接的第一背板331和第二背板332。第二背板332位于第一背板331背向电路板32b的一侧。第一背板331的热膨胀系数可以小于第二背板332的热膨胀系数。例如，第一背板331可以是预镀锌钢板，第二背板332可以是铝合金钢板。在其他一些实施例中，第一背板331和第二背板332也可以采用其他材料，只要保证第一背板331的热膨胀系数可以小于第二背板332的热膨胀系数即可，本申请实施例对此不作限定。
请一并参阅图5和图6，图6是图5所示衬底33b的变形示意图。在本实施例中，衬底33b采用双层结构，也即衬底33b包括层叠设置的第一背板331和第二背板332。第一背板331的热膨胀系数小于第二背板332的热膨胀系数，使得第一背板331的热变形量小于第二背板332的热变形量。衬底33b会向变形量大的第二背板332所在的一侧凸起，也即衬底33b的两端向上翘起，以匹配电路板32b的变形方式。因此，在本实施例中，当电路板32b、衬底33b等结构处的温度相对于常温发生变化时，衬底33b的凸起方向与电路板32b的凸起方向相同，避免电路板32b受衬底变形作用力的影响产生非自有变形，保持电路板32b处于裸板状态时的变形。同时，焊点36b不会受到向下的结构变形应力，提高焊点36b的温循疲劳寿命和电路板组件3b的使用寿命。
在其他一些实施例中，衬底33b也可以采用双层以上结构，例如，三层等，本申请实施例对此不作限定，只要满足当衬底33b处的温度相对于常温发生变化时，多层结构的热膨胀系数随与电路板32b的距离的增大而增大，衬底33b的凸起方向与电路板32b的凸起方向相同即可。
示例性的，在第二实施例中，衬底33b的热膨胀系数可以与电路板32b的热膨胀系数接近，也可以不接近，也即第二热膨胀系数与第一热膨胀系数之间的差值可以大于第一热膨胀系数的30％，以进一步减小衬底变形作用力的影响。在本实施例中，衬底33b的热膨胀系数为第一背板331和第二背板332组成的固定结构的总的热膨胀系数。
请参阅图7，图7是图2A所示电路板组件3在本申请提供的再一些实施例中的结构示意图。
在第三实施例中，电路板组件3c可以包括缓冲件37c，例如第一缓冲件371和第二缓冲件372，用于减小固定件34c对电路板32c和衬底33c的连接作用。其中，第一缓冲件371和第二缓冲件372可以分别设置在电路板32c的下侧和上侧。
示例性的，第一缓冲件371可以位于电路板32c的上侧，也即位于电路板32c背向衬底33c的一侧且接触电路板32c，固定件34c插接第一缓冲件371。固定件34c可以包括限位件341和插接件341，限位件341相对插接件341的周侧向外凸起，第一缓冲件371位于限位件341和电路板32c之间且接触限位件341及电路板32c。
示例性的，第二缓冲件372位于电路板32c的下侧，也即位于电路板32c与衬底33c之间且接触电路板32c及衬底33c，固定件34c插接所述第二缓冲件372。
请一并参阅图7和图8，图8是图7所示电路板组件3c的变形示意图。
在本实施例中，电路板组件3c受热时，电路板32c与衬底33c的相对位置发生变化，第一缓冲件371发生形变，以减小固定件34c和电路板32c之间的连接作用，增大电路板32c 在水平方向X上的变形空间，避免电路板32c的变形受到固定件34c的限制。第二缓冲件372发生形变，以减小电路板32c和衬底33c之间的连接作用，增大电路板32c和衬底33c在水平方向X上的变形空间，避免电路板32c的变形受到衬底变形作用力的影响。
在本实施例中，第一缓冲件371和第二缓冲件372可以减小固定件34c对电路板32c和衬底33c的连接作用，在保证固定件34c的紧固作用的同时、增加电路板32c和衬底33c在水平方向X上的变形空间，避免电路板32c产生非自有变形，保持电路板32c处于裸板状态时的变形，同时能够避免焊点36c受到结构变形应力，提高焊点36c的温循疲劳寿命和电路板组件3c的使用寿命。
示例性的，缓冲件37c也可以设于电路板32c的上侧或下侧，减小电路板32c及其相关组件的体积，使得电路板组件3c的结构更加紧凑，本申请对此不作限定。
示例性的，电路板组件3c也可以不设有固定件34c，电路板32c和衬底33c之间通过中间缓冲件(图未示)固定连接，也即电路板32c和衬底33c之间可以设有中间缓冲件，中间缓冲件的两侧分别固定连接电路板32c和衬底33c。中间缓冲件受力能够发生形变，利用中间缓冲件的变形性能，可以减少电路板32c和衬底33c之间的连接作用，抵消电路板32c和衬底33c之间的变形量差异，避免电路板32c的变形受到衬底变形作用力的影响，保持电路板32c处于裸板状态时的变形,以提高焊点36c的温循疲劳寿命。
示例性的，缓冲件37c可以采用橡胶、泡棉、PTFE(poly tetra fluoroethylene，聚四氟乙烯)等弹性材料，也可以采用弹簧等受力可以发生弹性变形的结构。缓冲件37c可以采用仿生设计结构，以便更好地匹配电路板32c变形后的形状、并增加固定件34c对电路板32c和衬底33c的紧固效果。
示例性的，在第三实施例中，衬底33c可以采用单层结构，也可以采用双层或双层以上结构，通过缓冲件37c及衬底33c变形匹配，保持电路板32c处于裸板状态时的变形，提升焊点36c的温循疲劳寿命。多层衬底33c的具体设置方式和结构可以参考第二实施例，在此不再赘述。
示例性的，在第三实施例中，衬底33c的热膨胀系数可以与电路板32c的热膨胀系数接近，以减小衬底33c与电路板32c之间的变形量差异，提高焊点36c的温循疲劳寿命。衬底33c的具体设置方式和结构可以参考第一实施例，在此不再赘述。可以理解地，衬底33c的热膨胀系数也可以与电路板32c的热膨胀系数不接近，本实施例对此不作限定。
请参阅图9，图9是图2A所示电路板组件3在本申请提供的还一些实施例中的结构示意图。在第四实施例中，电路板组件3d的大部分结构与第一实施例中相同，在此不再赘述。
示例性的，电路板组件3d可以包括托架38d，托架38d位于电路板32d背向衬底33d的一侧、且托架38d的两端可以通过固定件34d与电路板32d的两端固定连接。
示例性的，托架38d的中部与电路板32d的中部之间形成间隙。托架38d的热膨胀系数可以小于电路板32d的热膨胀系数，使得托架38d、电路板32d和衬底33d受热时，托架38d的变形量小于电路板32d的变形量。
请参阅图10，图10是图9所示电路板组件3d的变形示意图。当电路板32d、衬底33d、托架38d等结构处的温度相对于常温发生变化时，托架38d的变形量小于电路板32d的变形量，从而能够对电路板32d的两端施加的作用力，抵消衬底33d变形对电路板32d产生的衬底变形作用力，避免电路板32d产生非自有变形，保持电路板32d处于裸板状态时的变形，同时能够避免焊点36d受到向下的结构变形应力，提高焊点36d的温循疲劳寿命和电路板组件3d的使用寿命。
请参阅图11，图11是图2A所示电路板组件3在本申请提供的多一些实施例中的变形示意图。在第五实施例中，电路板组件3e的大部分结构与第四实施例中相同，在此不再赘述。示例性的，托架38e可以包括层叠设置且固定连接的上托架381和下托架382，上托架381位于下托架382背向电路板32e的一侧。上托架381和下托架382中的至少一者的两端固定连接电路板32e，下托架382的中部与电路板32e的中部之间形成间隙。
示例性的，上托架381的热膨胀系数可以小于下托架382的热膨胀系数，使得上托架381的热变形量小于下托架381的热变形量。托架38e会向变形量大的下托架381所在的一侧凸起，也即托架38e的两端向上翘起，以匹配电路板32e的变形方式。因此，在本申请中，当电路板32e、衬底33e、托架38e等结构处的温度相对于常温发生变化时，托架38e会对电路板32e的两端施加向上的作用力，以抵消衬底33e变形对电路板32e产生的斜向下的衬底变形作用力，保持电路板32e处于裸板状态时的变形。同时，焊点36e不会受到向下的结构变形应力，提高焊点36e的温循疲劳寿命。
示例性的，上托架381可以是预镀锌钢板，下托架382可以是铝合金钢板。在其他一些实施例中，上托架381和下托架382也可以采用其他材料，只要保证上托架381的热膨胀系数可以小于下托架382的热膨胀系数即可，本申请实施例对此不作限定。
在本实施例中，托架38e可以采用双层结构，也即包括层叠设置的上托架381和下托架382。在其他一些实施例中，托架38e也可以采用双层以上结构，例如，三层等，本申请实施例对此不作限定，只要满足当托架38e处的温度相对于常温发生变化时，多层结构的热膨胀系数随多层结构与电路板32e的距离的增大而减小，使得托架38e的凸起方向与电路板32e的凸起方向相同即可。
示例性的，在第五实施例中，单层或多层托架38e的总的变形量可以与电路板32e的变形量一致，在抵消衬底变形作用力的前提下，避免对电路板32e施加额外的变形作用力，保持电路板32e处于裸板状态时的变形，进一步提高焊点36e的温循疲劳寿命。
请一并参阅图10和图11，示例性的，在第四实施例和/或第五实施例中，电路板组件(3d，3e)也可以不包括固定件(34d，34e)，托架(38d，38e)的两端也可以通过焊接、胶接等方式与电路板(32d，32e)的两端固定连接，电路板(32d，32e)的中部可以相对托架(38d，38e)的中部运动，本申请对此不作限定。
示例性的，在第四实施例和/或第五实施例中，衬底(33d，33e)的热膨胀系数可以与电路板(32d，32e)的热膨胀系数接近，也可以不接近。
示例性的，在第四实施例和/或第五实施例中，电路板组件(3d，3e)的衬底(33d，33e)也可以采用双层或双层以上结构，通过衬底(33d，33e)的变形匹配以及托架(38d，38e)对衬底变形作用力的抵消作用，使电路板(32d，32e)处于裸板状态时的变形，提升焊点(36d，36e)的温循疲劳寿命。多层衬底(33d，33e)的具体设置方式和结构可以参考第二实施例，在此不再赘述。
示例性的，在第四实施例和/或第五实施例中，电路板组件(3d，3e)还可以包括缓冲件(图未示)，缓冲件可以设置于托架(38d，38e)与电路板(32d，32e)之间和/或电路板(32d，32e)与衬底(33d，33e)之间，通过缓冲件及托架(38d，38e)对衬底变形作用力的抵消作用，使电路板(32d，32e)的处于裸板状态时的变形，提升焊点(36d，36e)的温循疲劳寿命。缓冲件的具体设置方式以及结构可以参考第三实施例，在此不再赘述。
示例性的，在第四实施例和/或第五实施例中，固定件(34d，34e)可以插接托架(38d，38e)的两端，也即托架(38d，38e)的上表面接触或抵持固定件(34d，34e)的限位件(341d， 341e)，缓冲件则可以位于托架(38d，38e)与电路板(32d，32e)之间。
示例性的，请一并参阅图2A、图7和图9，在本申请实施例中，电路板组件3的装配步骤如下：
S1：将第一缓冲件371放置在衬底33上表面，之后将电路板32放置在第一缓冲件371上方，
和/或将第二缓冲件372放置在电路板32上方，第二缓冲件372可以和第一缓冲件371相对设置；
和/或将托架38d放置在电路板32或第二缓冲件372的上方。
S2：将固定件插接第一缓冲件371、电路板32和/或托架38d和/或第二缓冲件372、且与衬底33固定连接，将第一缓冲件371、电路板32、衬底33和/或托架38d和/或第二缓冲件372固定在一起。
示例性的，电路板组件3也可以不包括第一缓冲件371，此时电路板组件3的装配步骤如下：
S1：将电路板32放置在衬底33上表面，
和/或将第二缓冲件372放置在电路板32上方，第二缓冲件372可以和第一缓冲件371相对设置；
和/或将托架38d放置在电路板32或第二缓冲件372的上方。
S2：将固定件插接电路板32和/或托架38d和/或第二缓冲件372、并与衬底33固定连接，将电路板32、衬底33和/或托架38d和/或第二缓冲件372固定在一起。
以上描述，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本申请的保护范围之内；在不冲突的情况下，本申请的实施例及实施例中的特征可以相互组合。因此，本申请的保护范围应以权利要求的保护范围为准。

Claims (19)

  1. 一种电路板组件，其特征在于，包括电路板和固定于所述电路板一侧的衬底，所述电路板具有第一热膨胀系数，所述衬底具有第二热膨胀系数，所述第二热膨胀系数与所述第一热膨胀系数的差值小于或等于所述第一热膨胀系数的30％。
  2. 如权利要求1所述的电路板组件，其特征在于，所述衬底包括第一背板和第二背板，所述第二背板位于所述第一背板背向所述电路板的一侧，所述第一背板的热膨胀系数小于所述第二背板的热膨胀系数，所述第一背板和所述第二背板中的至少一者固定连接所述电路板。
  3. 如权利要求1或2所述的电路板组件，其特征在于，所述电路板组件还包括中间缓冲件，所述中间缓冲件的相背两侧分别固定连接所述电路板和所述衬底，所述中间缓冲件能够在外力作用下产生弹性形变。
  4. 如权利要求1或2所述的电路板组件，其特征在于，所述电路板组件还包括：
    固定件，所述电路板与所述衬底堆叠设置且两者之间形成间隙，所述固定件设于所述电路板两端，所述固定件插接所述电路板、且固定连接所述衬底，所述电路板组件受热时，所述电路板与所述衬底的相对位置发生变化；
    第一缓冲件，所述第一缓冲件位于所述电路板背向所述衬底的一侧且接触所述电路板，所述固定件插接所述第一缓冲件，所述电路板组件受热时，所述第一缓冲件发生形变；
    和/或第二缓冲件，所述第二缓冲件位于所述电路板与所述衬底之间且接触所述电路板及所述衬底，所述固定件插接所述第二缓冲件，所述电路板组件受热时，所述第二缓冲件发生形变。
  5. 如权利要求1至4中任一项所述的电路板组件，其特征在于，所述电路板组件还包括托架，所述托架位于所述电路板背向所述衬底的一侧、且所述托架的两端与所述电路板的两端固定连接，所述托架的中部与所述电路板的中部之间形成间隙，所述托架的热膨胀系数小于所述电路板的热膨胀系数。
  6. 如权利要求5所述的电路板组件，其特征在于，所述托架包括层叠设置且固定连接的上托架和下托架，所述上托架位于所述下托架背向所述电路板的一侧，所述上托架和所述下托架中的至少一者的两端固定连接所述电路板，所述下托架的中部与所述电路板的中部之间形成间隙，所述上托架的热膨胀系数小于所述下托架的热膨胀系数。
  7. 一种电路板组件，其特征在于，包括电路板和与所述电路板固定连接的衬底，所述衬底包括第一背板和第二背板，所述第二背板位于所述第一背板背向所述电路板的一侧，所述第一背板的热膨胀系数小于所述第二背板的热膨胀系数，所述第一背板和所述第二背板中的至少一者固定连接所述电路板。
  8. 如权利要求7所述的电路板组件，其特征在于，所述电路板组件还包括中间缓冲件，所述中间缓冲件的相背两侧分别固定连接所述电路板和所述衬底，所述中间缓冲件能够在外力作用下产生弹性形变。
  9. 如权利要求8所述的电路板组件，其特征在于，所述电路板组件还包括：
    固定件，所述电路板与所述衬底堆叠设置且两者之间形成间隙，所述固定件设于所述电路板两端，插接所述电路板、且固定连接所述衬底，所述电路板组件受热时，所述电路板与所述衬底的相对位置发生变化；
    第一缓冲件，所述第一缓冲件位于所述电路板背向所述衬底的一侧且接触所述电路板，所述固定件插接所述第一缓冲件，所述电路板组件受热时，所述第一缓冲件发生形变；
    和/或第二缓冲件，所述第二缓冲件位于所述电路板与所述衬底之间且接触所述电路板及所述衬底，所述固定件插接所述第二缓冲件，所述电路板组件受热时，所述第二缓冲件发生形变。
  10. 如权利要求7至9中任一项所述的电路板组件，其特征在于，所述电路板组件还包括托架，所述托架位于所述电路板背向所述衬底的一侧、且所述托架的两端与所述电路板的两端固定连接，所述托架的中部与所述电路板的中部之间形成间隙，所述托架的热膨胀系数小于所述电路板的热膨胀系数。
  11. 如权利要求10所述的电路板组件，其特征在于，所述托架包括层叠设置且固定连接的上托架和下托架，所述上托架位于所述下托架背向所述电路板的一侧，所述上托架和所述下托架中的至少一者的两端固定连接所述电路板，所述下托架的中部与所述电路板的中部之间形成间隙，所述上托架的热膨胀系数小于所述下托架的热膨胀系数。
  12. 一种电路板组件，其特征在于，包括电路板、衬底及固定件，所述电路板与所述衬底堆叠设置且两者之间形成间隙，所述固定件设于所述电路板两端，所述固定件插接所述电路板、且固定连接所述衬底，所述电路板组件受热时，所述电路板与所述衬底的相对位置发生变化；
    所述电路板组件还包括：
    第一缓冲件，所述第一缓冲件位于所述电路板背向所述衬底的一侧且接触所述电路板，所述固定件插接所述第一缓冲件，所述电路板组件受热时，所述第一缓冲件发生形变；
    和/或第二缓冲件，所述第二缓冲件位于所述电路板与所述衬底之间且接触所述电路板及所述衬底，所述固定件插接所述第二缓冲件，所述电路板组件受热时，所述第二缓冲件发生形变。
  13. 如权利要求12所述的电路板组件，其特征在于，所述第一缓冲件采用泡棉、橡胶或弹簧，和/或所述第二缓冲件采用泡棉、橡胶、PTFE或弹簧。
  14. 如权利要求12或13所述的电路板组件，其特征在于，所述固定件包括固定连接的限位件和插接件，所述限位件相对所述插接件的周侧向外凸起，所述第一缓冲件位于所述限位件和所述电路板之间且接触所述限位件及所述电路板。
  15. 如权利要求12至14中任一项所述的电路板组件，其特征在于，所述电路板组件还包括托架，所述托架位于所述电路板背向所述衬底的一侧、且所述托架的两端与所述电路板的两端固定连接，所述托架的中部与所述电路板的中部之间形成间隙，所述托架的热膨胀系数小于所述电路板的热膨胀系数。
  16. 如权利要求15所述的电路板组件，其特征在于，所述托架包括层叠设置且固定连接的上托架和下托架，所述上托架位于所述下托架背向所述电路板的一侧，所述上托架和所述下托架中的至少一者的两端固定连接所述电路板，所述下托架的中部与所述电路板的中部之间形成间隙，所述上托架的热膨胀系数小于所述下托架的热膨胀系数。
  17. 一种电路板组件，其特征在于，包括电路板、衬底和托架，所述衬底与所述电路板固定连接，所述托架位于所述电路板背向所述衬底的一侧、且所述托架的两端与所述电路板的两端固定连接，所述托架的中部与所述电路板的中部之间形成间隙，所述托架的热膨胀系数小于所述电路板的热膨胀系数。
  18. 如权利要求17所述的电路板组件，其特征在于，所述托架包括层叠设置且固定连接的上托架和下托架，所述上托架位于所述下托架背向所述电路板的一侧，所述上托架和所述下托架中的至少一者的两端固定连接所述电路板，所述下托架的中部与所述电路板的中部之 间形成间隙，所述上托架的热膨胀系数小于所述下托架的热膨胀系数。
  19. 一种电子设备，其特征在于，包括如权利要求1至18中任一项所述的电路板组件，所述电路板组件包括芯片，所述芯片固定于所述电路板背向所述衬底的一侧。
PCT/CN2022/085354 2021-04-27 2022-04-06 电路板组件及电子设备 WO2022228061A1 (zh)

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CN1108026A (zh) * 1993-09-21 1995-09-06 松下电器产业株式会社 电路基板连接件及用其制造多层电路基板的方法
CN206611636U (zh) * 2017-04-11 2017-11-03 丰郅(上海)新能源科技有限公司 抑制安装器件失效的印刷电路板布置结构
CN107535050A (zh) * 2015-02-18 2018-01-02 怡得乐工业有限公司 多层总线板

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CN1108026A (zh) * 1993-09-21 1995-09-06 松下电器产业株式会社 电路基板连接件及用其制造多层电路基板的方法
CN107535050A (zh) * 2015-02-18 2018-01-02 怡得乐工业有限公司 多层总线板
CN206611636U (zh) * 2017-04-11 2017-11-03 丰郅(上海)新能源科技有限公司 抑制安装器件失效的印刷电路板布置结构

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