Circuit board assembly, manufacturing method for circuit board assembly, and electronic device

Abstract

Embodiments of the present application provide a circuit board assembly, a manufacturing method for the circuit board assembly, and an electronic device, for use in solving the problem in the related art of low reliability of electronic components. The circuit board assembly comprises a circuit board, a first electronic component, a filling material, a second electronic component, and an isolation material. The first electronic component is soldered to a first side of the circuit board by means of a first bump. The filling material is at least partially located between the first electronic component and the circuit board, and the filling material covers the first bump. The second electronic component is soldered to the first side of the circuit board by means of a second bump, the second electronic component and the first electronic component are arranged in a first direction, and the first direction is perpendicular to the thickness direction of the circuit board. The isolation material covers at least part of the second electronic component, the isolation material is in contact with the filling material, and the elastic modulus of the isolation material is smaller than that of the filling material. The isolation material can prevent the filling material from coming into contact with the second electronic component, thereby reducing the stress on the second electronic component.

Description

Circuit board assembly, method for preparing circuit board assembly, and electronic device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on January 17, 2024, with application number 202410076030.4 and application name “Circuit board assembly, method for preparing circuit board assembly and electronic device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The embodiments of the present application relate to a circuit board assembly, a method for preparing a circuit board assembly, and an electronic device, belonging to the field of electronic devices. Background Art

[0003] The circuit board assembly can be a printed circuit board assembly (PCBA). A circuit board assembly includes a printed circuit board (PCB) and at least one electronic device electrically connected to the PCB. Electronic devices such as chips can be soldered to the circuit board using solder balls. To improve the connection reliability between the chip and the circuit board, an underfill is typically placed between the chip and the circuit board. However, the underfill may adhere to other electronic devices, reducing the reliability of these other electronic devices.

[0004] Summary of the Invention

[0005] Embodiments of the present application provide a circuit board assembly, a method for preparing a circuit board assembly, and an electronic device, which are used to improve the problem of low reliability of electronic devices in related technologies.

[0006] To achieve the above objectives, the present invention provides the following solutions:

[0007] On the one hand, a circuit board assembly is provided, which includes a circuit board, a first electronic device, a filling material, a second electronic device, and an isolation material. The first electronic device is soldered to the first side of the circuit board via a first bump. The filling material is at least partially located between the first electronic device and the circuit board, and the filling material wraps the first bump. The second electronic device is soldered to the first side of the circuit board via the second bump, and the second electronic device and the first electronic device are arranged along a first direction, which is perpendicular to the thickness direction of the circuit board. The isolation material wraps at least a portion of the second electronic device, and the isolation material is in contact with the filling material, and the elastic modulus of the isolation material is smaller than the elastic modulus of the filling material. Through the above arrangement, the isolation material can prevent the filling material from contacting the second electronic device. Since the elastic modulus of the isolation material can be smaller than the elastic modulus of the filling material, when the circuit board assembly is impacted, the stress on the second electronic device is reduced, which is conducive to improving the reliability of the second electronic device.

[0008] Furthermore, since the isolation material wraps the second electronic device, the isolation material can prevent the filling material from contacting the second electronic device, which is beneficial to reducing the distance between the first electronic device and the second electronic device along the first direction, thereby facilitating the miniaturization of the circuit board assembly.

[0009] In some implementations, the second electronic device includes a body, a coil, and an electrode, wherein the electrode covers the surface of the body, and the coil extends from the interior of the body to the surface of the body and contacts the electrode. The portion of the electrode that contacts the coil is enclosed by an insulating material. This arrangement prevents the portion of the electrode that contacts the coil from contacting the filler material, thereby preventing the connection between the electrode and the coil from breaking when the circuit board assembly is impacted, thereby improving the reliability of the second electronic device.

[0010] In some implementations, the second electronic device includes a semiconductor layer and an interconnect layer stacked along a first direction, the interconnect layer being closer to the circuit board than the semiconductor layer and connected to the second bump; and an isolation material encapsulating the semiconductor layer and the interconnect layer. This arrangement prevents the semiconductor layer and the interconnect layer from contacting the filler material, thereby preventing failures such as delamination between the semiconductor layer and the interconnect layer when the circuit board assembly is impacted, thereby improving the reliability of the second electronic device.

[0011] In some implementations, a portion of the isolation material is further positioned between the second electronic device and the circuit board, with the isolation material encapsulating the second bumps. This arrangement further prevents the second bumps from contacting the filler material, reduces stress on the second bumps, and improves the reliability of the second electronic device.

[0012] In some implementations, the isolation material includes acrylic resin or epoxy resin. Specifically, when the isolation material includes only acrylic resin, the elastic modulus of the isolation material can be less than 0.003 GPa. For example, the elastic modulus of the isolation material can be 0.002 GPa, 0.0015 GPa, or 0.001 GPa. When the isolation material includes only epoxy resin, the elastic modulus of the isolation material can be less than 0.5 GPa. For example, the elastic modulus of the isolation material can be 0.45 GPa, 0.4 GPa, or 0.35 GPa. In actual application, isolation materials of different materials can be selected according to actual needs, which is beneficial to further reduce the stress on the second electronic device and improve the reliability of the second electronic device.

[0013] In some implementations, the filling material includes epoxy resin and filling particles, and the filling particles are embedded in the epoxy resin. Embedding the filling particles in the epoxy resin helps increase the elastic modulus of the epoxy resin and improve the connection reliability between the first electronic device and the circuit board.

[0014] In another aspect, a method for preparing a circuit board assembly is provided. The circuit board assembly includes a circuit board, a first electronic device, and a second electronic device. The method comprises: soldering the first electronic device to a first side of the circuit board via a first bump; soldering the second electronic device to the first side of the circuit board via a second bump, wherein the second electronic device and the first electronic device are arranged along a first direction perpendicular to the thickness of the circuit board; disposing an isolation material on the second electronic device so that the isolation material encapsulates at least a portion of the second electronic device; and disposing a filler material between the first electronic device and the circuit board so that the filler material encapsulates the first bump, the filler material contacts the isolation material, and the elastic modulus of the isolation material is lower than that of the filler material. Providing the filler material between the first electronic device and the circuit board improves the connection reliability between the first electronic device and the circuit board. Because the filler material contacts the isolation material, the isolation material prevents contact between the filler material and the second electronic device. Because the elastic modulus of the isolation material can be lower than that of the filler material, stress on the second electronic device is reduced when the circuit board assembly is impacted, thereby improving the reliability of the second electronic device.

[0015] In some implementations, the isolation material includes an acrylic resin. After the isolation material is provided on the second electronic device and before the filling material is provided between the first electronic device and the circuit board, the method further includes: pre-curing the isolation material through an ultraviolet (UV) curing process. The above-mentioned arrangement facilitates pre-shaping of the isolation material and improves the wrapping effect of the isolation material on the second electronic device. After the filling material is provided between the first electronic device and the circuit board, the method further includes: thermally curing the isolation material and the filling material. The above-mentioned arrangement enables the isolation material and the filling material to be cured and formed in one step, which simplifies the curing steps of the isolation material and the filling material and improves the preparation efficiency of the circuit board assembly.

[0016] In some implementations, the isolation material includes epoxy resin. After placing the filler material between the first electronic device and the circuit board, the method further includes thermally curing the isolation material and the filler material. This arrangement allows the isolation material and the filler material to be cured and formed simultaneously, further simplifying the curing steps for the isolation material and the filler material and improving the efficiency of circuit board assembly production. Furthermore, since pre-curing of the isolation material is not required, the processing cost of the circuit board assembly is reduced.

[0017] In another aspect, a method for preparing a circuit board assembly is provided. The circuit board assembly includes a circuit board, a first electronic device, and a second electronic device. The method comprises: soldering the first electronic device to a first side of the circuit board via a first bump; placing an isolation material on the second electronic device so that the isolation material encapsulates the second electronic device and the solder terminals of the second electronic device are exposed outside the isolation material; soldering the second electronic device to the first side of the circuit board via the second bump, with the second electronic device and the first electronic device arranged along a first direction perpendicular to the thickness of the circuit board; placing a filler material between the first electronic device and the circuit board so that the filler material encapsulates the first bump and contacts the isolation material. Providing the filler material between the first electronic device and the circuit board improves the connection reliability between the first electronic device and the circuit board. Because the filler material contacts the isolation material, the isolation material prevents contact between the filler material and the second electronic device. Because the elastic modulus of the isolation material can be smaller than that of the filler material, the stress on the second electronic device is reduced when the circuit board assembly is impacted, thereby improving the reliability of the second electronic device.

[0018] In some implementations, the insulating material includes an acrylic resin. After the insulating material is provided on the second electronic device and before the second electronic device is soldered to the first side of the circuit board via the second bump, the method further includes: pre-curing the insulating material through an ultraviolet curing process. The above-mentioned arrangement facilitates pre-shaping of the insulating material and improves the wrapping effect of the insulating material on the second electronic device. After the filling material is provided between the first electronic device and the circuit board, the method further includes: thermally curing the insulating material and the filling material. The above-mentioned arrangement enables the insulating material and the filling material to be cured and formed in one step, which simplifies the curing steps of the insulating material and the filling material and improves the preparation efficiency of the circuit board assembly.

[0019] In some implementations, the isolation material includes epoxy resin. Soldering the second electronic device to the first side of the circuit board via the second bump further includes: melting the isolation material under heat so that the isolation material wraps around the second bump. After providing a filler material between the first electronic device and the circuit board, the method further includes: thermally curing the isolation material and the filler material. This arrangement allows the isolation material to wrap around both the second electronic device and the second bump, further preventing contact between the second bump and the filler material. This reduces stress on the second bump and improves the reliability of the second electronic device.

[0020] In some implementations, the isolation material includes epoxy resin. After the isolation material is provided on the second electronic device and before the second electronic device is soldered to the first side of the circuit board via the second bump, the method further includes: thermally curing the isolation material. By thermally curing the isolation material, the isolation material is shaped to prevent the isolation material from flowing and obscuring the soldering terminals of the second electronic device. After the filler material is provided between the first electronic device and the circuit board, the method further includes: thermally curing the filler material. The above-mentioned arrangement allows the filler material to be cured and formed, which helps to improve the connection reliability between the first electronic device and the circuit board.

[0021] In another aspect, an electronic device is provided, comprising a circuit board assembly as described in any of the above embodiments and a battery, wherein the battery powers the first electronic device and the second electronic device of the circuit board assembly. The electronic device provided in the embodiments of the present application includes the above circuit board assembly, and thus has all the aforementioned beneficial effects, which are not further elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG1 is a structural diagram of an electronic device provided in an embodiment of the present application;

[0023] FIG2 is a structural diagram of a circuit board provided in an embodiment of the present application;

[0024] FIG3 is a structural diagram of a circuit board assembly provided in some embodiments;

[0025] FIG4 is a structural diagram of a circuit board assembly provided in some other embodiments;

[0026] FIG5 is a structural diagram of a circuit board assembly provided in an embodiment of the present application;

[0027] FIG6 is a partial enlarged view of a circuit board assembly at point M in FIG5 ;

[0028] FIG7 is a partial enlarged view of another circuit board assembly at position M in FIG5 ;

[0029] FIG8 is a partial enlarged view of another circuit board assembly at position M in FIG5 ;

[0030] FIG9 is a partial enlarged view of another circuit board assembly at position M in FIG5 ;

[0031] FIG10 is a flowchart of a method for preparing a circuit board assembly according to an embodiment of the present application;

[0032] FIG11 is a structural diagram of a method for preparing a circuit board assembly provided in an embodiment of the present application after curing an isolation material and a filling material;

[0033] FIG12 is another structural diagram of a method for preparing a circuit board assembly provided in an embodiment of the present application after curing the isolation material and the filling material;

[0034] FIG13 is a flowchart of another method for preparing a circuit board assembly according to an embodiment of the present application;

[0035] FIG14 is another structural diagram of another method for preparing a circuit board assembly provided in an embodiment of the present application after curing the isolation material and the filling material. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0037] In the following, the terms "first," "second," etc., are used for descriptive convenience only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature specified as "first," "second," etc. may explicitly or implicitly include one or more of such features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0038] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0039] In the embodiments of the present application, directional indications such as up, down, left, right, front, and back, used to explain the structure and movement of various components of the present application are relative. These indications are appropriate when the components are in the positions shown in the figures. However, if the description of the component positions changes, these directional indications will also change accordingly.

[0040] When describing some embodiments, the word "connected" and its derivatives may be used. The term "connected" should be understood broadly. For example, "connected" can mean fixed, removable, or integrated; it can be directly connected or indirectly connected through an intermediary. The embodiments disclosed herein are not necessarily limited to the contents of this document.

[0041] Additionally, the use of “based on” is meant to be open and inclusive, as a process, step, calculation, or other action “based on” one or more stated conditions or values ​​may, in practice, be based on additional conditions or values ​​beyond those stated.

[0042] As used herein, "about" or "approximately" includes the stated value and the average value that is within an acceptable range of deviation from the particular value, where the acceptable range of deviation is determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0043] Here, "perpendicular" includes the described situation and situations similar to the described situation, wherein the range of the similar situation is within an acceptable deviation range, where the acceptable deviation range is determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system). For example, "perpendicular" includes absolute perpendicularity and approximately perpendicularity, where the acceptable deviation range for approximately perpendicularity can be, for example, a deviation of within 5%.

[0044] The present invention provides an electronic device 1, wherein the electronic device 1 may be a mobile phone, a tablet computer (pad), a television, a smart wearable product (e.g., a smart watch, a smart bracelet), a virtual reality (VR) device, an augmented reality (AR) device, or other terminal products.

[0045] Figure 1 is a structural diagram of an electronic device provided in an embodiment of the present application; Figure 2 is a structural diagram of a circuit board provided in an embodiment of the present application. Referring to Figures 1 and 2, electronic device 1 may include a battery 20 and a printed circuit board assembly (PCBA) 10. Battery 20 is used to power circuit board assembly 10. The power source may be, for example, a lithium-ion battery 20. Circuit board assembly 10 may include a circuit board 11. Circuit board 11 may be a printed circuit board (PCB), a flexible circuit board, an integrated circuit (or chip), etc. Depending on the number of electronic components carried on circuit board 11, circuit board 11 may be a single-sided board or a double-sided board. A single-sided board may refer to a circuit board that carries electronic components on one side. A double-sided board may refer to a circuit board that carries electronic components on both sides. Depending on the type of electronic components carried on circuit board 11, circuit board 11 may be a mainboard, a module board, a frame board (FB), a radio frequency (RF) board, an application processor (AP) board, etc.

[0046] As shown in FIG1 , electronic device 1 may include two circuit board assemblies 10. The circuit board 11 in one circuit board assembly 10 may be a mainboard, which may be the main circuit board within electronic device 1. The circuit board 11 in the other circuit board assembly 10 may be a radio frequency board. The radio frequency board may be used to carry radio frequency integrated circuits (RF ICs), radio frequency power amplifiers (RF PAs), wireless fidelity (WIFI) chips, and the like.

[0047] When the circuit board 11 in the circuit board assembly 10 is a mainboard, the circuit board assembly 10 may further include a first electronic device 12, which is connected to the circuit board 11. The first electronic device 12 may include an integrated circuit device, such as an application processor (AP), a double data rate synchronous dynamic random access memory (DDR), a universal flash storage (UFS), a power management unit (PMU), etc. In some examples, as shown in FIG2 , the circuit board 11 may be integrated with multiple circuits adapted to specific functions, such as a display circuit, a radio frequency circuit, a camera circuit, a storage circuit, an audio circuit, a sensor circuit, etc.

[0048] FIG3 is a structural diagram of a circuit board assembly provided in some embodiments. In some embodiments, referring to FIG3 , the first electronic device 12 ′ can be fixed to the first side A of the circuit board 11 ′ by welding the first bump 31 ′. For example, the first bump 31 ′ can be a solder ball, that is, the first electronic device 12 ′ can be connected to the circuit board 11 ′ via a flip chip-ball grid array (FCBGA). The bumps described in this application may refer to solder materials used to mechanically and / or electrically connect a circuit board and an electronic component. The actual shape of the bumps described in this application is not necessarily spherical, and may be a polyhedron, a sphere, an ellipsoid, a truncated cone, a chamfered shape, etc.

[0049] 3 , the circuit board assembly 10′ may further include a second electronic device 13′, which may be welded and fixed to the first side A of the circuit board 11′. The second electronic device 13′ and the first electronic device 12′ are arranged along a first direction X, and the first direction X is perpendicular to the thickness direction of the circuit board (the thickness direction of the circuit board assembly may be, for example, the Y direction in FIG3 ). In some embodiments, the second electronic device 13′ may be a stress-sensitive element. Here, “stress-sensitive element” may be understood as the second electronic device 13′ being prone to failure when subjected to stress shock, and the second electronic device 13′ may include, for example, electronic devices such as chips and inductors. The embodiment of the present application does not specifically limit the second electronic device 13′.

[0050] Continuing with FIG3 , the circuit board assembly 10′ may further include a filler material 14′. At least a portion of the filler material 14′ may be located between the first electronic device 12′ and the circuit board 11′ and may encapsulate the first bump 31′. The filler material 14′ may be an underfill. Providing the filler material 14′ may improve the connection reliability between the first electronic device 12′ and the circuit board 11′. The elastic modulus of the filler material 14′ may be greater than 2 GPa.

[0051] In some embodiments, to achieve miniaturization of circuit board assembly 10', the distance between first electronic device 12' and second electronic device 13' is relatively small. For example, distance D1 between first electronic device 12' and second electronic device 13' along first direction X may be 0.1 mm. When the distance between first electronic device 12' and second electronic device 13' is relatively small, excess filler material 14' can easily contact the surface of second electronic device 13'. Due to the high elastic modulus of filler material 14', when second electronic device 13' is subjected to external stress, second electronic device 13' is prone to failure. For example, when circuit board assembly 10' is subjected to mechanical shock, the high elastic modulus of filler material 14' can cause a greater impact force on second electronic device 13'. Alternatively, when circuit board assembly 10' is subjected to thermal shock, the high coefficient of thermal expansion of filler material 14' can cause significant dimensional changes in filler material 14' due to thermal expansion or contraction. Furthermore, due to the high elastic modulus of filler material 14', the tensile force on second electronic device 13' can be relatively large.

[0052] In some embodiments, in order to prevent excess filling material 14' from contacting the second electronic device 13', the distance between the first electronic device 12' and the second electronic device 13' along the first direction X is increased. Figure 4 is a structural diagram of a circuit board assembly provided in some other embodiments. Referring to Figure 4, the distance D2 between the first electronic device 12' and the second electronic device 13' along the first direction X may be greater than or equal to 0.5 mm. However, the above arrangement makes it difficult to achieve miniaturization of the circuit board assembly 10'. The circuit board assembly 10' occupies a large space in the electronic device 1, squeezing the space occupied by other components inside the electronic device 1 (such as a camera module, a battery, etc.), thereby affecting the performance of other components inside the electronic device 1.

[0053] Figure 5 is a structural diagram of a circuit board assembly according to an embodiment of the present application. As shown in Figure 5 , the circuit board assembly according to the embodiment of the present application may include a first electronic device 12, first bumps 31, filler material 14, and circuit board 11. Circuit board assembly 10 may also include a second electronic device 13 and an isolation material 15, which encapsulates at least a portion of second electronic device 13.

[0054] In some embodiments, the isolation material 15 may be a cured adhesive. The adhesive may be wrapped around the second electronic device 13 through a dispensing process, and then cured to form the isolation material 15. For example, the isolation material 15 may be substantially spherical, and at least a portion of the second electronic device 13 may be located within the isolation material 15. Of course, the isolation material 15 in the embodiments of the present application may also be of other shapes or materials, and the embodiments of the present application are not specifically limited thereto.

[0055] Continuing with FIG5 , the isolation material 15 can be in contact with the filling material 14 , and the elastic modulus of the isolation material 15 can be smaller than that of the filling material 14 . With this arrangement, the isolation material 15 can prevent the filling material 14 from coming into contact with the second electronic device 13 . Because the elastic modulus of the isolation material 15 can be smaller than that of the filling material 14 , when the circuit board assembly 10 is impacted, the stress on the second electronic device 13 is reduced, thereby improving the reliability of the second electronic device 13 .

[0056] Furthermore, since the isolation material 15 wraps the second electronic device 13, the isolation material 15 can prevent the filling material 14 from contacting the second electronic device 13, which is beneficial to reducing the distance between the first electronic device 12 and the second electronic device 13 along the first direction X, and further beneficial to miniaturizing the circuit board assembly 10.

[0057] In some embodiments, the distance D3 between the first electronic device 12 and the second electronic device 13 along the first direction X can be in the range of 0.05mm-0.25mm. For example, the distance between the first electronic device 12 and the second electronic device 13 along the first direction X can be 0.05mm, 0.1mm, 0.15mm, 0.2mm or 0.25mm. For example, according to the requirements of 0.5mm no device isolation zone and 2mm prohibited layout, the circuit board assembly 10 in the embodiment of the present application can provide 240mm-360mm 2 area benefits.

[0058] In some embodiments, the isolation material 15 may include acrylic resin and / or epoxy resin. Here, "and / or" may be inclusive, and may be understood as the isolation material 15 comprising only acrylic resin, or the isolation material 15 comprising only epoxy resin, or the isolation material 15 comprising both acrylic resin and epoxy resin.

[0059] Among them, when the isolation material 15 only includes acrylic resin, the elastic modulus of the isolation material 15 can be less than 0.003GPa. For example, the elastic modulus of the isolation material 15 can be 0.002GPa, 0.0015GPa or 0.001GPa. When the isolation material 15 only includes epoxy resin, the elastic modulus of the isolation material 15 can be less than 0.5GPa. For example, the elastic modulus of the isolation material 15 can be 0.45GPa, 0.4GPa or 0.35GPa. In actual application, isolation materials 15 of different materials can be selected according to actual needs, which is beneficial to further reduce the stress on the second electronic device 13 and improve the reliability of the second electronic device 13.

[0060] In some embodiments, filler material 14 may include epoxy resin and filler particles, with the filler particles embedded in the epoxy resin. The filler particles may be made of silicon dioxide, aluminum oxide, or the like. Embedding the filler particles in the epoxy resin increases the elastic modulus of the epoxy resin, thereby improving the connection reliability between first electronic device 12 and circuit board 11.

[0061] In some embodiments, second electronic device 13 may include an inductor. Figure 6 is a partial, enlarged view of a portion M of one circuit board assembly in Figure 5 ; Figure 7 is a partial, enlarged view of a portion M of another circuit board assembly in Figure 5 . The following describes the position of isolation material 15 when second electronic device 13 includes an inductor, with reference to Figures 6 and 7 .

[0062] The second electronic device 13 may include a body 131 , a coil 132 and an electrode 133 . The electrode 133 covers the surface of the body 131 . The coil 132 extends from the inside of the body 131 to the surface of the body 131 and contacts the electrode 133 .

[0063] In some embodiments, body 131 may include a top surface 131a and a bottom surface 131b, wherein top surface 131a and bottom surface 131b are arranged along the thickness direction of the circuit board (the Y direction shown in FIG. 6 or 7 ), and bottom surface 131b is closer to circuit board 11 than top surface 131a. Second electronic device 13 may further include a side surface 131c, which may be adjacent to top surface 131a and bottom surface 131b.

[0064] Continuing with reference to Figures 6 and 7, the coil 132 can extend from the interior of the body 131 to the side surface 131c of the body 131. The electrode 133 can extend from the side surface 131c of the body 131 to the bottom surface 131b of the body 131. The electrode 133 located on the side surface 131c can be the first conductive portion 1333 of the electrode 133, and the electrode 133 located on the bottom surface 131b can be the second conductive portion 1335 of the electrode 133. In the thickness direction of the circuit board 11 (the Y direction as shown in Figures 6 or 7), one end of the first conductive portion 1333 is connected to the coil 132, and the other end of the first conductive portion 1333 is connected to the second conductive portion 1335.

[0065] Continuing with reference to Figures 6 and 7 , and in conjunction with Figure 5 , the isolation material 15 can wrap around the portion of the electrode 133 that contacts the coil 132. For example, the isolation material 15 can wrap around the top surface 131a and at least a portion of the side surface 131c, and can also wrap around at least a portion of the first conductive portion 1333. This arrangement prevents the portion of the electrode 133 that contacts the coil 132 from contacting the filler material 14, thereby preventing the connection between the electrode 133 and the coil 132 from breaking when the circuit board assembly 10 is impacted, thereby improving the reliability of the second electronic device 13.

[0066] In some embodiments, as shown in FIG6 , isolation material 15 covers at least half of first conductive portion 1333 in the thickness direction of circuit board 11 (the Y direction in FIG6 ). This arrangement helps increase the coverage area of ​​isolation material 15, further preventing contact between electrode 133 and filler material 14, and preventing breakage at the connection between electrode 133 and coil 132, thereby further improving the reliability of second electronic device 13.

[0067] 6 , the electrode 133 can be electrically connected to the circuit board 11 through the second bump 32. For example, the electrode 133 can contact the second bump 32, and the second bump 32 can contact the circuit board 11. With the above arrangement, the coil 132 can be electrically connected to the circuit board 11 through the electrode 133 and the second bump 32.

[0068] Continuing with FIG. 7 and in conjunction with FIG. 5 , the isolation material 15 may further wrap around the second bumps 32. For example, when the isolation material 15 is a cured adhesive, excess adhesive can be dispensed to wrap around the second electronic device 13 and the second bumps 32. This arrangement further prevents contact between the second bumps 32 and the filling material 14, reduces stress on the second bumps 32, and improves the reliability of the second electronic device 13.

[0069] In some embodiments, second electronic device 13 may include a chip. Figure 8 is a partial enlarged view of the M portion of another circuit board assembly in Figure 5 ; Figure 9 is a partial enlarged view of the M portion of another circuit board assembly in Figure 5 . The following describes the position of isolation material 15 when second electronic device 13 includes a chip, with reference to Figures 8 and 9 .

[0070] The chip may be, for example, a wafer level chip scale packaging (WLCSP) chip. For example, the second electronic device 13 may include a semiconductor layer 135 and an interconnection layer 137 stacked along a first direction X. The interconnection layer 137 is closer to the circuit board 11 than the semiconductor layer 135, and the interconnection layer 137 is connected to the second bump 32. The semiconductor layer 135 may have a plurality of conductive circuits, and the interconnection layer 137 may be electrically connected to the conductive circuits in the semiconductor layer 135, so that the conductive circuits in the semiconductor layer 135 are electrically connected to the circuit board 11 through the interconnection layer 137. The material of the interconnection layer 137 may include at least one of a low dielectric constant (low k, LK) or an ultra-low dielectric constant (extreme low k, ELK) material.

[0071] 8 and 9 , in conjunction with FIG. 5 , isolation material 15 may wrap around semiconductor layer 135 and interconnect layer 137. For example, isolation material 15 may wrap around the side surface of semiconductor layer 135, and isolation material 15 may also wrap around the side surface of interconnect layer 137. This arrangement prevents contact between semiconductor layer 135 and interconnect layer 137 and filler material 14, respectively. When circuit board assembly 10 is impacted, failures such as delamination between semiconductor layer 135 and interconnect layer 137 are prevented, thereby improving the reliability of second electronic device 13.

[0072] 8 and 9 , interconnect layer 137 can be connected to circuit board 11 via second bumps 32. For example, second bumps 32 can be a ball grid array. Through the above arrangement, semiconductor layer 135 is electrically connected to circuit board 11 via interconnect layer 137 and second bumps 32.

[0073] Referring to FIG. 9 , in conjunction with FIG. 5 , the isolation material 15 may further wrap around the second bumps 32. For example, when the isolation material 15 is a cured adhesive, excess adhesive can be dispensed to wrap around the second electronic device 13 and the second bumps 32. This arrangement further prevents contact between the second bumps 32 and the filler material 14, reduces stress on the second bumps 32, and improves the reliability of the second electronic device 13.

[0074] In summary, providing the isolation material 15 outside the second electronic device 13 to wrap the second electronic device 13 is beneficial for reducing the stress on the second electronic device 13. In some embodiments, the stress on the second electronic device 13 can be reduced.

[0075] For example, when the elastic modulus of the filling material 14 is equal to 3 GPa, and the filling material 14 is in contact with the second electronic device 13, the stress on the second electronic device 13 is 100% of the nominal stress, and the failure rate obtained by the reliability test is 30%; when the elastic modulus of the isolation material 15 is equal to 0.466 GPa, and the isolation material 15 is in contact with the second electronic device 13, the stress on the second electronic device 13 is 64% of the nominal stress, the improvement in the stress on the second electronic device 13 is 36%, and the failure rate obtained by the reliability test is 0 %; when the elastic modulus of the isolation material 15 is equal to 0.0014 GPa and the isolation material 15 is in contact with the second electronic device 13, the stress to which the second electronic device 13 is subjected is 34% of the nominal stress, the improvement in the stress to which the second electronic device 13 is subjected is 66%, and the failure rate obtained by the reliability test is 0%; when the surface of the second electronic device 13 is not glued, the stress to which the second electronic device 13 is subjected is 38% of the nominal stress, the improvement in the stress to which the second electronic device 13 is subjected is 62%, and the failure rate obtained by the reliability test is 0%.

[0076] The present application also provides a method for preparing a circuit board assembly 10, which is used to prepare the circuit board assembly 10 of any of the above-mentioned embodiments. Circuit board assembly 10 includes a circuit board 11, a first electronic device 12, and a second electronic device 13. FIG. 10 is a flowchart of the steps of the method for preparing circuit board assembly 10 provided in the present application. Referring now to FIG. 5 and FIG. 10 , the method for preparing circuit board assembly 10 may include steps S101-S104.

[0077] S101, soldering a first electronic component to a first side of a circuit board through a first bump.

[0078] As described in the above embodiment, the first bumps 31 may be solder balls, that is, the first electronic device 12 may be connected to the circuit board 11 through a ball grid array.

[0079] In the embodiment of the present application, after the first electronic device 12 is soldered to the circuit board 11 , the method for preparing the circuit board assembly 10 may further include step S102 .

[0080] S102 , soldering the second electronic component to the first side of the circuit board through the second bump, wherein the second electronic component and the first electronic component are arranged along a first direction, and the first direction is perpendicular to the thickness direction of the circuit board.

[0081] In some embodiments, the structure of the second bump 32 may be as shown in FIG. 6 to FIG. 9 , and will not be further described herein.

[0082] As described in the above embodiment, the second electronic device 13 may include, for example, an inductor, a chip, etc. Through the above arrangement, the second electronic device 13 and the first electronic device 12 are arranged on the same side of the circuit board 11 .

[0083] In the embodiment of the present application, after the second electronic device 13 is soldered to the first side of the circuit board 11 through the second bumps 32 , the method for preparing the circuit board assembly 10 may further include step S103 .

[0084] S103 , disposing an isolation material on the second electronic device so that the isolation material wraps at least a portion of the second electronic device.

[0085] In some embodiments, as shown in Figures 6 and 8 , the isolation material 15 can be wrapped around the second electronic device 13. Alternatively, in some embodiments, as shown in Figures 7 and 9 , the isolation material 15 can also be wrapped around the second bump 32. The present embodiment does not specifically limit the shape of the isolation material 15, as long as it can wrap at least a portion of the second electronic device 13.

[0086] In the embodiment of the present application, after the isolation material 15 is provided on the second electronic device 13 , the method for preparing the circuit board assembly 10 may further include step S104 .

[0087] S104 , placing a filling material between the first electronic component and the circuit board, so that the filling material wraps the first bump, the filling material contacts the isolation material, and the elastic modulus of the isolation material is smaller than the elastic modulus of the filling material.

[0088] Providing filler material 14 between first electronic device 12 and circuit board 11 helps improve the connection reliability between first electronic device 12 and circuit board 11. Since filler material 14 is in contact with isolation material 15, isolation material 15 can prevent filler material 14 from contacting second electronic device 13. Since the elastic modulus of isolation material 15 can be lower than that of filler material 14, when circuit board assembly 10 is impacted, the stress on second electronic device 13 is reduced, which helps improve the reliability of second electronic device 13.

[0089] In some embodiments, the isolation material 15 may include an acrylic resin. FIG11 illustrates a structure diagram of a circuit board assembly after curing the isolation material and the filler material, in a method for preparing a circuit board assembly according to an embodiment of the present application. FIG11 (a) illustrates a structure diagram after pre-curing the isolation material; FIG11 (b) illustrates a structure diagram after thermally curing the isolation material and the filler material.

[0090] As shown in FIG11(a), after disposing isolation material 15 on second electronic device 13 and before disposing filler material 14 between first electronic device 12 and circuit board 11, the method for preparing circuit board assembly 10 further includes pre-curing isolation material 15 via a UV curing process. UV curing equipment 40 can be used to pre-cure isolation material 15. This arrangement facilitates pre-setting isolation material 15 and improves the effectiveness of isolation material 15 wrapping around second electronic device 13.

[0091] As shown in FIG11( b ), after placing filler material 14 between first electronic device 12 and circuit board 11, the method for preparing circuit board assembly 10 further includes thermally curing isolation material 15 and filler material 14. This arrangement allows isolation material 15 and filler material 14 to be cured and formed simultaneously, simplifying the curing steps for isolation material 15 and filler material 14 and improving the efficiency of preparing circuit board assembly 10.

[0092] In some embodiments, the isolation material 15 may include an epoxy resin. The epoxy resin may be a thermosetting type. FIG12 illustrates another structural diagram of a circuit board assembly fabrication method provided in an embodiment of the present application, after curing the isolation material and the filler material. FIG12 (a) illustrates the structural diagram after the isolation material is disposed outside the second electronic device; FIG12 (b) illustrates the structural diagram after the isolation material and the filler material have been thermoset.

[0093] As shown in FIG12(a), after the isolation material 15 is provided on the second electronic device 13, there is no need to pre-cure the isolation material 15. Furthermore, as shown in FIG12(b), after the filler material 14 is provided between the first electronic device 12 and the circuit board 11, the method for preparing the circuit board assembly 10 further includes: thermally curing the isolation material 15 and the filler material 14. Through the above arrangement, the isolation material 15 and the filler material 14 are cured and formed in one step, which helps to further simplify the curing steps of the isolation material 15 and the filler material 14 and further improve the production efficiency of the circuit board assembly 10. Furthermore, since there is no need to pre-cure the isolation material 15, it helps to reduce the processing cost of the circuit board assembly 10.

[0094] The embodiment of the present application also provides a method for preparing a circuit board assembly 10, which is used to prepare the circuit board assembly 10 in any of the above embodiments. The circuit board assembly 10 includes a circuit board 11, a first electronic device 12, and a second electronic device 13. Figure 13 is a flow chart of the steps of another method for preparing a circuit board assembly 10 provided in an embodiment of the present application. Figure 14 is another structural diagram of another method for preparing a circuit board assembly provided in an embodiment of the present application after curing the isolation material and the filling material. Referring to Figure 5 and in combination with Figures 13 and 14, the method for preparing the circuit board assembly 10 may include steps S201-S204.

[0095] S201: Solder a first electronic component to a first side of a circuit board via a first bump.

[0096] As described in the above embodiment, the first bumps 31 may be solder balls, that is, the first electronic device 12 may be connected to the circuit board 11 through a ball grid array.

[0097] In the embodiment of the present application, after the first electronic device 12 is soldered to the circuit board 11 , the method for preparing the circuit board assembly 10 may further include step S202 .

[0098] S202 , disposing an isolation material on the second electronic device so that the isolation material wraps the second electronic device and the welding terminals of the second electronic device are exposed outside the isolation material.

[0099] FIG. 14 ( a ) is a structural diagram after an isolation material 15 is provided on the second electronic device 13 , and the isolation material 15 wraps the second electronic device 13 .

[0100] The "soldering terminal" may be a metal connection portion of the second electronic device 13 used for fixed welding or electrical connection. For example, when the second electronic device 13 is an inductor, the soldering terminal of the second electronic device 13 may be an electrode 133; when the second electronic device 13 is a chip, the soldering terminal of the second electronic device 13 may be a pin. The specific structure of the soldering terminal is not limited in this embodiment of the application.

[0101] In the embodiment of the present application, after the isolation material 15 is provided on the second electronic device 13 , the method for preparing the circuit board assembly 10 may further include step S203 .

[0102] S203 , soldering the second electronic component to the first side of the circuit board through the second bump, wherein the second electronic component and the first electronic component are arranged along a first direction, and the first direction is perpendicular to the thickness direction of the circuit board.

[0103] In some embodiments, the structure of the second bump 32 can be shown in FIG6 to FIG9 , which will not be described in detail. Through the above arrangement, the second electronic device 13 and the first electronic device 12 are arranged on the same side of the circuit board 11 .

[0104] FIG. 14 ( b ) is a structural diagram after the second electronic device 13 is welded to the circuit board. The second electronic device 13 can be welded to the first side A of the circuit board 11 through the second bumps 32 .

[0105] In the embodiment of the present application, after the second electronic device 13 is soldered to the first side A of the circuit board 11 through the second bumps 32 , the method for preparing the circuit board assembly 10 may further include step S204 .

[0106] S204 , placing a filling material between the first electronic device and the circuit board, so that the filling material wraps the first bump, the filling material contacts the isolation material, and the elastic modulus of the isolation material is smaller than the elastic modulus of the filling material.

[0107] FIG14(c) shows the structure after a filler material is provided between the first electronic device and the circuit board. Referring to FIG14(c), the provision of filler material 14 between first electronic device 12 and circuit board 11 helps improve the connection reliability between first electronic device 12 and circuit board 11. Since filler material 14 is in contact with isolation material 15, isolation material 15 can prevent filler material 14 from contacting second electronic device 13. Since the elastic modulus of isolation material 15 can be lower than that of filler material 14, when circuit board assembly 10 is impacted, the stress on second electronic device 13 is reduced, thereby improving the reliability of second electronic device 13.

[0108] In some embodiments, the isolation material 15 may include acrylic resin.

[0109] When the isolation material 15 includes acrylic resin, after the above-mentioned step S202 and before step S203, the isolation material 15 can also be pre-cured by an ultraviolet curing process. For example, after the isolation material 15 wraps the second electronic device 13, before the second electronic device 13 is soldered to the first side A of the circuit board 11 through the second bump 32, the isolation material 15 can be pre-cured by an ultraviolet curing process.

[0110] The above arrangement is advantageous for pre-shaping the isolation material 15 , and is advantageous for improving the wrapping effect of the isolation material 15 on the second electronic device 13 .

[0111] In the above step S204 , after the filling material 14 is provided between the first electronic device 12 and the circuit board 11 , the isolation material 15 and the filling material 14 may be thermally cured.

[0112] Through the above arrangement, the isolation material 15 and the filling material 14 are cured and formed at one time, which is beneficial to simplify the curing steps of the isolation material 15 and the filling material 14 and improve the preparation efficiency of the circuit board assembly 10.

[0113] In some embodiments, the isolation material 15 may include epoxy resin, wherein the epoxy resin may be of B-Stage type.

[0114] In step S203, when isolation material 15 comprises a B-Stage epoxy resin and second electronic device 13 is soldered to first side A of circuit board 11 via second bumps 32, isolation material 15 is heated and melted, thereby encapsulating second bumps 32. Exemplarily, during the soldering process between second electronic device 13 and circuit board 11, the soldering temperature is transferred to isolation material 15, causing isolation material 15 to melt due to the heat. The melted isolation material 15 then encapsulates second bumps 32.

[0115] In the above step S204 , after the filling material 14 is provided between the first electronic device 12 and the circuit board 11 , the isolation material 15 and the filling material 14 may be thermally cured.

[0116] Through the above arrangement, the isolation material 15 can wrap the second electronic device 13 while also wrapping the second bump 32 , which is beneficial to further avoid the second bump 32 from contacting the filling material 14 , reducing the stress on the second bump 32 , and improving the reliability of the second electronic device 13 .

[0117] In some embodiments, the isolation material 15 may include epoxy resin, wherein the epoxy resin may be a thermosetting type.

[0118] When the isolation material 15 includes a thermosetting epoxy resin, the isolation material 15 can be thermoset after the above-mentioned step S202 and before step S203. For example, after the isolation material 15 wraps the second electronic device 13, the isolation material 15 can be thermoset before the second electronic device 13 is soldered to the first side A of the circuit board 11 through the second bump 32.

[0119] The isolation material 15 is thermally cured to achieve shaping of the isolation material 15 , thereby preventing the isolation material 15 from flowing and shielding the soldering terminals of the second electronic device 13 .

[0120] In the above step S204 , after the filling material 14 is provided between the first electronic device 12 and the circuit board 11 , the filling material 14 may be thermally cured.

[0121] Through the above arrangement, the filling material 14 is solidified and formed, which is beneficial to improving the connection reliability between the first electronic device 12 and the circuit board 11 .

[0122] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any modifications or substitutions conceived by a person skilled in the art within the technical scope disclosed in this application are intended to be within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be based on the scope of protection of the claims.

Claims

1. A circuit board assembly, characterized in that, The circuit board assembly includes: A circuit board; A first electronic device, soldered to the first side of the circuit board through a first bump; A filling material, at least partially located between the first electronic device and the circuit board, and the filling material wraps the first bump; A second electronic device, soldered to the first side of the circuit board through a second bump, the second electronic device and the first electronic device are arranged along a first direction, and the first direction is perpendicular to the thickness direction of the circuit board; An isolation material, wrapping at least part of the second electronic device, the isolation material is in contact with the filling material, and the elastic modulus of the isolation material is less than the elastic modulus of the filling material.

2. The circuit board assembly according to claim 1, characterized in that, The second electronic device includes a body, a coil and an electrode, the electrode covers the surface of the body, the coil extends from the inside of the body to the surface of the body and is in contact with the electrode; The isolation material wraps the part where the electrode is in contact with the coil.

3. The circuit board assembly according to claim 1, wherein The second electronic device includes a semiconductor layer and an interconnection layer stacked along the first direction, the interconnection layer is closer to the circuit board than the semiconductor layer, and the interconnection layer is connected to the second bump; The isolation material wraps the semiconductor layer and the interconnection layer.

4. The circuit board assembly according to any one of claims 1-3, characterized in that, The isolation material also wraps the second bump.

5. The circuit board assembly according to any one of claims 1-4, characterized in that, The isolation material includes acrylic resin or epoxy resin.

6. The circuit board assembly according to any one of claims 1-5, characterized in that, The filling material includes epoxy resin and filling particles, and the filling particles are embedded in the epoxy resin.

7. A method for preparing a circuit board assembly, the circuit board assembly comprising a circuit board, a first electronic device, and a second electronic device, characterized in that, The preparation method of the circuit board assembly includes: Solder the first electronic device to the first side of the circuit board through a first bump; Solder the second electronic device to the first side of the circuit board through a second bump, the second electronic device and the first electronic device are arranged along a first direction, and the first direction is perpendicular to the thickness direction of the circuit board; Set an isolation material on the second electronic device so that the isolation material wraps at least part of the second electronic device; Set a filling material between the first electronic device and the circuit board so that the filling material wraps the first bump, the filling material is in contact with the isolation material, and the elastic modulus of the isolation material is less than the elastic modulus of the filling material.

8. The preparation method of the circuit board assembly according to claim 7, characterized in that, The isolation material includes acrylic resin; After setting the isolation material on the second electronic device and before setting the filling material between the first electronic device and the circuit board, it further includes: Pre-cure the isolation material through an ultraviolet curing process; After setting the filling material between the first electronic device and the circuit board, it further includes: Thermally cure the isolation material and the filling material.

9. The preparation method of the circuit board assembly according to claim 7, characterized in that, The isolation material includes epoxy resin; After setting the filling material between the first electronic device and the circuit board, it further includes: Thermally cure the isolation material and the filling material.

10. A method for preparing a circuit board assembly, the circuit board assembly including a circuit board, a first electronic device, and a second electronic device, characterized in that, The preparation method of the circuit board assembly includes: Solder the first electronic device to the first side of the circuit board through a first bump; Set an isolation material on the second electronic device so that the isolation material wraps the second electronic device, and the welding terminals of the second electronic device are exposed outside the isolation material; The second electronic device is soldered to the first side of the circuit board through second bumps, and the second electronic device and the first electronic device are arranged along a first direction perpendicular to the thickness direction of the circuit board; A filling material is disposed between the first electronic device and the circuit board to wrap the first bumps with the filling material, and the filling material contacts an isolation material, and the elastic modulus of the isolation material is less than that of the filling material. The isolation material includes acrylic resin; 11. The preparation method of the circuit board assembly according to claim 10, characterized in that, After the isolation material is disposed on the second electronic device and before the second electronic device is soldered to the first side of the circuit board through second bumps, it further includes: Pre-curing the isolation material by an ultraviolet curing process; After the filling material is disposed between the first electronic device and the circuit board, it further includes: Thermally curing the isolation material and the filling material. The isolation material includes epoxy resin; 12. The manufacturing method of the circuit board assembly according to claim 10, characterized in that, When the second electronic device is soldered to the first side of the circuit board through second bumps, it further includes: the isolation material is heated and melted to wrap the second bumps; After the filling material is disposed between the first electronic device and the circuit board, it further includes: Thermally curing the isolation material and the filling material. The isolation material includes epoxy resin; 13. The preparation method of the circuit board assembly according to claim 10, characterized in that, After the isolation material is disposed on the second electronic device and before the second electronic device is soldered to the first side of the circuit board through second bumps, it further includes: Thermally curing the isolation material; After the filling material is disposed between the first electronic device and the circuit board, it further includes: Thermally curing the filling material. It includes a circuit board assembly and a battery as described in any one of claims 1-6 above, and the battery supplies power to the first and second electronic devices of the circuit board assembly.

14. An electronic device, characterized in that, ​

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