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 assemblies, methods for manufacturing circuit board assemblies, and electronic devices

[0001] This application claims priority to Chinese patent application filed on January 17, 2024, with application number 202410076030.4 and entitled "Circuit Board Assembly, Method for Preparing Circuit Board Assembly and Electronic Device", the entire contents of which are incorporated herein by reference. Technical Field

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

[0003] A 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 component electrically connected to the PCB. Electronic components such as chips can be soldered onto the circuit board using solder balls. To improve the reliability of the connection between the chip and the circuit board, an underfill is typically filled between the chip and the circuit board. However, the underfill may adhere to other electronic components, leading to a decrease in the reliability of those components.

[0004] Summary of the Invention

[0005] This application provides a circuit board assembly, a method for manufacturing the circuit board assembly, and an electronic device to improve the problem of low reliability of electronic devices in related technologies.

[0006] To achieve the above objectives, the embodiments of this application provide the following solutions:

[0007] On one hand, a circuit board assembly is provided, comprising a circuit board, a first electronic device, a filler material, a second electronic device, and an insulating material. The first electronic device is soldered to a first side of the circuit board via a first bump. The filler material is at least partially located between the first electronic device and the circuit board, and the filler material covers the first bump. The second electronic device is soldered to the first side of the circuit board via a second bump, 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. The insulating material covers at least a portion of the second electronic device, and the insulating material is in contact with the filler material. The elastic modulus of the insulating material is less than that of the filler material. Through the above arrangement, the insulating material can prevent the filler material from contacting the second electronic device. Since the elastic modulus of the insulating material can be less than that of the filler material, the stress on the second electronic device is reduced when the circuit board assembly is subjected to impact, which is beneficial to improving the reliability of the second electronic device.

[0008] Furthermore, since the insulating material encapsulates the second electronic device, the insulating material can prevent the filling material from contacting the second electronic device, which helps to reduce the distance between the first and second electronic devices 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 electrodes. The electrodes cover the surface of the body, and the coil extends from the interior of the body to its surface, contacting the electrodes. An insulating material covers the portion of the electrode that contacts the coil. This arrangement prevents the portion of the electrode that contacts the coil from coming into contact with the filling material, thereby preventing breakage at the connection between the electrode and the coil when the circuit board assembly is subjected to impact, and 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 is closer to the circuit board than the semiconductor layer and is connected to a second bump. An insulating material covers the semiconductor layer and the interconnect layer. This arrangement prevents the semiconductor layer and the interconnect layer from coming into contact with the filler material, thus preventing delamination and other failures between the semiconductor layer and the interconnect layer when the circuit board assembly is subjected to impact, thereby improving the reliability of the second electronic device.

[0011] In some implementations, a portion of the insulating material is also located between the second electronic device and the circuit board, with the insulating material wrapping around the second bump. This arrangement helps to further prevent the second bump from contacting the filling material, reducing the stress on the second bump and improving the reliability of the second electronic device.

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

[0013] In some implementations, the filler material includes epoxy resin and filler particles, with the filler particles embedded within the epoxy resin. Embedding filler particles within the epoxy resin increases the elastic modulus of the epoxy resin, thereby improving the reliability of the connection between the first electronic device and the circuit board.

[0014] On the other hand, a method for manufacturing a circuit board assembly is also provided. The circuit board assembly includes a circuit board, a first electronic device, and a second electronic device. The method includes: 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 direction of the circuit board; providing an insulating material on the second electronic device so that the insulating material covers at least a portion of the second electronic device; and providing a filler material between the first electronic device and the circuit board so that the filler material covers the first bump, the filler material is in contact with the insulating material, and the elastic modulus of the insulating material is less than that of the filler material. By providing a filler material between the first electronic device and the circuit board, the connection reliability between the first electronic device and the circuit board is improved. Since the filler material is in contact with the insulating material, the insulating material can prevent the filler material from contacting the second electronic device. Since the elastic modulus of the insulating material can be less than that of the filler material, the stress on the second electronic device is reduced when the circuit board assembly is subjected to impact, which is beneficial to improving the reliability of the second electronic device.

[0015] In some implementations, the insulating material includes acrylic resin. After the insulating material is applied to the second electronic device and before the filler material is applied between the first electronic device and the circuit board, the process further includes pre-curing the insulating material using an ultraviolet (UV) curing process. This pre-curing facilitates the shaping of the insulating material and improves its encapsulation effect on the second electronic device. After the filler material is applied between the first electronic device and the circuit board, the process further includes thermosetting both the insulating material and the filler material. This allows for a single-step curing of the insulating material and the filler material, simplifying the curing steps and improving the fabrication efficiency of the circuit board assembly.

[0016] In some implementations, the insulating material includes epoxy resin. After the filler material is placed between the first electronic device and the circuit board, the process further includes thermosetting the insulating material and the filler material. This arrangement allows the insulating material and the filler material to be cured in a single step, which simplifies the curing process and improves the manufacturing efficiency of the circuit board assembly. Furthermore, since pre-curing of the insulating material is unnecessary, it helps reduce the processing cost of the circuit board assembly.

[0017] On the other hand, a method for manufacturing a circuit board assembly is also provided. The circuit board assembly includes a circuit board, a first electronic device, and a second electronic device. The method for manufacturing the circuit board assembly includes: soldering the first electronic device to a first side of the circuit board via a first bump; providing an insulating material on the second electronic device such that the insulating material covers the second electronic device, and the solder terminals of the second electronic device are exposed outside the insulating material; soldering the second electronic device to the first side of the circuit board via a second bump, the second electronic device and the first electronic device being arranged along a first direction perpendicular to the thickness direction of the circuit board; and providing a filler material between the first electronic device and the circuit board such that the filler material covers the first bump, and the filler material is in contact with the insulating material. By providing a filler material between the first electronic device and the circuit board, the connection reliability between the first electronic device and the circuit board is improved. Since the filler material is in contact with the insulating material, the insulating material can prevent the filler material from contacting the second electronic device. Since the elastic modulus of the insulating 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 subjected to impact, which is beneficial to improving the reliability of the second electronic device.

[0018] In some implementations, the insulating material includes acrylic resin. After the insulating material is applied to 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 process further includes pre-curing the insulating material using a UV curing process. This arrangement facilitates pre-shaping of the insulating material and improves its encapsulation effect on the second electronic device. After a filler material is applied between the first electronic device and the circuit board, the process further includes thermosetting both the insulating material and the filler material. This arrangement allows for one-time curing of the insulating material and the filler material, simplifying the curing steps and improving the fabrication efficiency of the circuit board assembly.

[0019] In some implementations, the insulating 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 insulating material by heat to encapsulate the second bump. After placing a filler material between the first electronic device and the circuit board, the process further includes: thermosetting the insulating material and the filler material. This arrangement ensures that the insulating material encapsulates both the second electronic device and the second bump, further preventing contact between the second bump and the filler material, reducing stress on the second bump, and improving the reliability of the second electronic device.

[0020] In some implementations, the insulating material includes epoxy resin. After the insulating material is applied to 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: thermosetting the insulating material. Thermosetting the insulating material helps to shape it and prevents it from flowing and obstructing the solder terminals of the second electronic device. After a filler material is applied between the first electronic device and the circuit board, the method further includes: thermosetting the filler material. These steps allow the filler material to cure and solidify, which helps to improve the connection reliability between the first electronic device and the circuit board.

[0021] On the other hand, an electronic device is also provided, including a circuit board assembly as described in any of the above embodiments and a battery, wherein the battery powers a first electronic device and a second electronic device of the circuit board assembly. The electronic device provided by the embodiments of this application includes the circuit board assembly as described above, and therefore has all the aforementioned beneficial effects, which will not be repeated here. Attached Figure Description

[0022] Figure 1 is a structural diagram of an electronic device provided in an embodiment of this application;

[0023] Figure 2 is a structural diagram of a circuit board provided in an embodiment of this application;

[0024] Figure 3 is a structural diagram of a circuit board assembly provided in some embodiments;

[0025] Figure 4 is a structural diagram of a circuit board assembly provided in some other embodiments;

[0026] Figure 5 is a structural diagram of a circuit board assembly provided in an embodiment of this application;

[0027] Figure 6 is a partial enlarged view of point M in one of the circuit board components in Figure 5;

[0028] Figure 7 is a partial enlarged view of point M of another circuit board assembly in Figure 5;

[0029] Figure 8 is a partial enlarged view of point M in another circuit board assembly in Figure 5;

[0030] Figure 9 is a partial enlarged view of point M in another circuit board assembly in Figure 5;

[0031] Figure 10 is a flowchart of the steps of a method for manufacturing a circuit board assembly according to an embodiment of this application;

[0032] Figure 11 is a structural diagram of the insulation material and the filler material after curing in a method for preparing a circuit board assembly according to an embodiment of this application;

[0033] Figure 12 is a structural diagram of the insulation material and the filler material after curing in another method for preparing a circuit board assembly according to an embodiment of this application;

[0034] Figure 13 is a flowchart of another method for preparing a circuit board assembly according to an embodiment of this application;

[0035] Figure 14 is a structural diagram of another method for preparing a circuit board assembly according to an embodiment of this application, after curing the isolation material and the filler material. Detailed Implementation

[0036] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0037] In the following description, the terms "first," "second," etc., are used for ease of description only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "multiple" means two or more.

[0038] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0039] In the embodiments of this application, the directional indications used to explain the structure and movement of different components, such as up, down, left, right, front, and back, 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] In describing some embodiments, the term "connection" and its derivative expressions may be used. The term "connection" should be interpreted broadly; for example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium. The embodiments disclosed herein are not necessarily limited to the content of this document.

[0041] In addition, the use of “based on” implies openness and inclusivity, because processes, steps, calculations or other actions “based on” one or more of the 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 within an acceptable range of deviation from the given value, wherein the acceptable range of deviation is determined by a person skilled in the art taking into account the measurement under discussion and the error associated with the measurement of the given quantity (i.e., the limitations of the measurement system).

[0043] Here, "vertical" includes the described situation and situations similar to the described situation, where the range of similarity is within an acceptable deviation range, which is determined by someone skilled in the art taking into account the measurement under discussion and the error associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "vertical" includes absolute verticality and approximate verticality, where an acceptable deviation range for approximate verticality could be, for example, a deviation within 5%.

[0044] This application provides an electronic device. The electronic device 1 can be a mobile phone, tablet computer, television, smart wearable products (e.g., smartwatches, smart bracelets), virtual reality (VR) devices, augmented reality (AR) devices, or other terminal products.

[0045] Figure 1 is a structural diagram of an electronic device provided in an embodiment of this application; Figure 2 is a structural diagram of a circuit board provided in an embodiment of this application. Referring to Figures 1 and 2, the electronic device 1 may include a battery 20 and a printed circuit board assembly (PCBA) 10. The battery 20 is used to supply power to the circuit board assembly 10, and the power source may be, for example, a lithium-ion battery 20. The circuit board assembly 10 may include a circuit board 11. The 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 the circuit board 11, the 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 the circuit board 11, the circuit board 11 may be a motherboard, a module board, a frame board (FB), a radio frequency (RF) board, an application processor (AP) board, etc.

[0046] As shown in Figure 1, the electronic device 1 may include two circuit board assemblies 10. One circuit board assembly 10 may contain a circuit board 11 that can be a motherboard, which may be the main circuit board within the electronic device 1. The other circuit board assembly 10 may contain a radio frequency (RF) board. The RF board can be used to carry radio frequency integrated circuits (RF ICs), radio frequency power amplifiers (RF PAs), wireless fidelity (WIFI) chips, etc.

[0047] When the circuit board 11 in the circuit board assembly 10 is a motherboard, 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 integrated circuit devices, such as an application processor (AP), double data rate synchronous dynamic random access memory (DDR), universal flash storage (UFS), power management unit (PMU), etc. In some examples, as shown in FIG2, the circuit board 11 may integrate multiple circuits adapted to specific functions, such as display circuits, radio frequency circuits, imaging circuits, storage circuits, audio circuits, sensor circuits, etc.

[0048] Figure 3 is a structural diagram of a circuit board assembly provided in some embodiments. In some embodiments, referring to Figure 3, a first electronic device 12' can be soldered and fixed to a first side A of the circuit board 11' via a 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 can refer to solder used for mechanical and / or electrical connections between the circuit board and electronic components. The actual shape of the bumps described in this application is not necessarily spherical; it can be a polyhedron, sphere, ellipsoid, frustum, chamfered, etc.

[0049] Referring to Figure 3, the circuit board assembly 10' may further include a second electronic device 13', which can be soldered 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, which is perpendicular to the thickness direction of the circuit board (the thickness direction of the circuit board assembly can be, for example, the Y direction in Figure 3). In some embodiments, the second electronic device 13' can be a stress-sensitive element. Here, "stress-sensitive element" can be understood as the second electronic device 13' being prone to failure when subjected to stress impact. The second electronic device 13' may include, for example, electronic devices such as chips and inductors. This application embodiment does not specifically limit the second electronic device 13'.

[0050] Referring again to Figure 3, the circuit board assembly 10' may further include a filler material 14', at least a portion of which may be located between the first electronic device 12' and the circuit board 11', and wrap around the first bump 31'. The filler material 14' may be an underfill. The use of the filler material 14' improves the reliability of the connection 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 the circuit board assembly 10', the distance between the first electronic device 12' and the second electronic device 13' is small. For example, the distance D1 between the first electronic device 12' and the second electronic device 13' along the first direction X can be 0.1 mm. When the distance between the first electronic device 12' and the second electronic device 13' is small, excess filler material 14' easily comes into contact with the surface of the second electronic device 13'. Due to the high elastic modulus of the filler material 14', the second electronic device 13' is prone to failure when subjected to external stress. For example, when the circuit board assembly 10' is subjected to mechanical impact, the second electronic device 13' experiences a large impact force due to the high elastic modulus of the filler material 14'; or, when the circuit board assembly 10' is subjected to thermal shock, the filler material 14' has a large coefficient of thermal expansion, resulting in a large dimensional change in the filler material 14' due to thermal expansion or cold contraction, and due to the high elastic modulus of the filler material 14', the second electronic device 13' experiences a large tensile impact force.

[0052] In some embodiments, to avoid excessive filler material 14' 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 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 can 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', and 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 camera modules, batteries, 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 provided in an embodiment of this application. Referring to Figure 5, the circuit board assembly in this embodiment may include a first electronic device 12, a first bump 31, a filler material 14, and a circuit board 11. The circuit board assembly 10 may also include a second electronic device 13 and an insulating material 15, wherein the insulating material 15 encapsulates at least a portion of the second electronic device 13.

[0054] In some embodiments, the insulating material 15 can be a cured adhesive. The adhesive can be applied by dispensing to encapsulate the second electronic device 13, and then cured to form the insulating material 15. For example, the insulating material 15 can be generally spherical, and at least a portion of the second electronic device 13 can be located within the insulating material 15. Of course, the insulating material 15 in this embodiment can also be of other shapes or materials, and this embodiment does not impose specific limitations on this.

[0055] Referring again to Figure 5, the insulating material 15 can contact the filler material 14, and the elastic modulus of the insulating material 15 can be less than that of the filler material 14. Through this arrangement, the insulating material 15 can prevent the filler material 14 from contacting the second electronic device 13. Since the elastic modulus of the insulating material 15 can be less than that of the filler material 14, the stress on the second electronic device 13 is reduced when the circuit board assembly 10 is subjected to impact, which helps to improve the reliability of the second electronic device 13.

[0056] Furthermore, since the insulating material 15 encloses the second electronic device 13, the insulating 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, thereby facilitating the miniaturization of 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 range from 0.05mm to 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 a 0.5mm no-device isolation strip and a 2mm prohibition zone, the circuit board assembly 10 in this embodiment can provide a 240mm-360mm... 2 Area benefits.

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

[0059] When the insulating material 15 consists only of acrylic resin, its elastic modulus can be less than 0.003 GPa. For example, the elastic modulus of the insulating material 15 can be 0.002 GPa, 0.0015 GPa, or 0.001 GPa. When the insulating material 15 consists only of epoxy resin, its elastic modulus can be less than 0.5 GPa. For example, the elastic modulus of the insulating material 15 can be 0.45 GPa, 0.4 GPa, or 0.35 GPa. In practical applications, different insulating materials 15 can be selected according to actual needs, which helps to further reduce the stress on the second electronic device 13 and improve its reliability.

[0060] In some embodiments, the filler material 14 may include epoxy resin and filler particles, with the filler particles embedded within the epoxy resin. The filler particles may be made of materials such as silica or alumina. Embedding filler particles within the epoxy resin increases the elastic modulus of the epoxy resin, thereby improving the reliability of the connection between the first electronic device 12 and the circuit board 11.

[0061] In some embodiments, the second electronic device 13 may include an inductor. FIG6 is a partial enlarged view of point M in one type of circuit board assembly in FIG5; FIG7 is a partial enlarged view of point M in another type of circuit board assembly in FIG5. Referring to FIG6 and FIG7, the position of the insulating material 15 when the second electronic device 13 includes an inductor will be described below.

[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, and the coil 132 extends from the interior of the body 131 to the surface of the body 131 and contacts the electrode 133.

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

[0064] Referring again 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 a first conductive portion 1333 of the electrode 133, and the electrode 133 located on the bottom surface 131b can be a second conductive portion 1335 of the electrode 133. In the thickness direction of the circuit board 11 (the Y direction as shown in Figure 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] Referring again to Figures 6 and 7, and in conjunction with Figure 5, the insulating material 15 can cover the portion of the electrode 133 that contacts the coil 132. For example, the insulating material 15 can cover the top surface 131a and at least a portion of the side surface 131c, and it can also cover 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 filling material 14, thereby preventing breakage at the connection between the electrode 133 and the coil 132 when the circuit board assembly 10 is subjected to impact, thus improving the reliability of the second electronic device 13.

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

[0067] Referring again to Figure 6, electrode 133 can be electrically connected to circuit board 11 via second protrusion 32. For example, electrode 133 can contact second protrusion 32, and second protrusion 32 can contact circuit board 11. With this configuration, coil 132 can be electrically connected to circuit board 11 via electrode 133 and second protrusion 32.

[0068] Referring again to Figure 7 and in conjunction with Figure 5, the insulating material 15 can also wrap around the second protrusion 32. For example, when the insulating material 15 is a cured adhesive, excess adhesive can be applied using a dispensing process to wrap around the second electronic device 13 and the second protrusion 32. This arrangement helps to further prevent the second protrusion 32 from contacting the filler material 14, reduces the stress on the second protrusion 32, and improves the reliability of the second electronic device 13.

[0069] In some embodiments, the second electronic device 13 may include a chip. FIG8 is a partial enlarged view of point M in another circuit board assembly of FIG5; FIG9 is a partial enlarged view of point M in another circuit board assembly of FIG5. The position of the insulating material 15 when the second electronic device 13 includes a chip will be described below with reference to FIG8 and FIG9.

[0070] The chip can be, for example, a wafer-level chip-scale package (WLCSP) chip. For instance, the second electronic device 13 may include a semiconductor layer 135 and an interconnect layer 137 stacked along a first direction X. The interconnect layer 137 is closer to the circuit board 11 than the semiconductor layer 135 and is connected to the second bump 32. The semiconductor layer 135 may have multiple conductive lines, and the interconnect layer 137 can be electrically connected to these conductive lines, so that the conductive lines in the semiconductor layer 135 are electrically connected to the circuit board 11 via the interconnect layer 137. The material of the interconnect 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] Referring to Figures 8 and 9, and in conjunction with Figure 5, the insulating material 15 can encapsulate the semiconductor layer 135 and the interconnect layer 137. For example, the insulating material 15 can be encapsulated on the side surface of the semiconductor layer 135, and it can also be encapsulated on the side surface of the interconnect layer 137. This arrangement prevents the semiconductor layer 135 and the interconnect layer 137 from contacting the filler material 14, thus preventing delamination and other failure phenomena between the semiconductor layer 135 and the interconnect layer 137 when the circuit board assembly 10 is subjected to impact, thereby improving the reliability of the second electronic device 13.

[0072] Referring again to Figures 8 and 9, the interconnect layer 137 can be connected to the circuit board 11 via the second bump 32. For example, the second bump 32 can be a ball grid array. This arrangement allows the semiconductor layer 135 to be electrically connected to the circuit board 11 via the interconnect layer 137 and the second bump 32.

[0073] Referring to Figure 9 and in conjunction with Figure 5, the insulating material 15 can also wrap around the second protrusion 32. For example, when the insulating material 15 is a cured adhesive, excess adhesive can be applied using a dispensing process to wrap around the second electronic device 13 and the second protrusion 32. This arrangement helps to further prevent the second protrusion 32 from contacting the filler material 14, reduces the stress on the second protrusion 32, and improves the reliability of the second electronic device 13.

[0074] In summary, by providing an insulating material 15 to enclose the second electronic device 13, it is beneficial to reduce 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 filler material 14 is equal to 3 GPa, and the filler material 14 is in contact with the second electronic device 13, the stress experienced by the second electronic device 13 is 100% of the nominal stress, and the failure rate obtained through reliability testing is 30%. When the elastic modulus of the insulating material 15 is equal to 0.466 GPa, and the insulating material 15 is in contact with the second electronic device 13, the stress experienced by the second electronic device 13 is 64% of the nominal stress, the stress reduction of the second electronic device 13 is 36%, and the failure rate obtained through reliability testing is 0. When the elastic modulus of the insulating material 15 is equal to 0.0014 GPa, and the insulating material 15 is in contact with the second electronic device 13, the stress on the second electronic device 13 is 34% of the nominal stress, the improvement in stress on the second electronic device 13 is 66%, and the failure rate obtained through reliability testing is 0%. When the surface of the second electronic device 13 is not adhesive, the stress on the second electronic device 13 is 38% of the nominal stress, the improvement in stress on the second electronic device 13 is 62%, and the failure rate obtained through reliability testing is 0%.

[0076] This application also provides a method for fabricating a circuit board assembly 10, used to fabricate 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 10 is a flowchart illustrating the steps of a method for fabricating a circuit board assembly 10 according to an embodiment of this application. Referring to Figure 5 and Figure 10, the method for fabricating the circuit board assembly 10 may include steps S101-S104.

[0077] S101. The first electronic device is soldered to the first side of the circuit board through the first bump.

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

[0079] In this embodiment of the 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. The second electronic device is soldered to the first side of the circuit board through the second bump. The second electronic device and the first electronic device are arranged along the first direction, which is perpendicular to the thickness direction of the circuit board.

[0081] In some embodiments, the structure of the second protrusion 32 can be as shown in Figures 6 to 9, and will not be described again here.

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

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

[0084] S103. An insulating material is disposed on the second electronic device so that the insulating material covers at least part of the second electronic device.

[0085] In some embodiments, as shown in Figures 6 and 8, the insulating material 15 may wrap around the second electronic device 13. Alternatively, in some embodiments, as shown in Figures 7 and 9, the insulating material 15 may also wrap around the second protrusion 32. The embodiments of this application do not specifically limit the shape of the insulating material 15, as long as it can wrap around at least part of the second electronic device 13.

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

[0087] S104. A filler material is provided between the first electronic device and the circuit board so that the filler material wraps around the first bump, the filler material is in contact with the isolation material, and the elastic modulus of the isolation material is less than that of the filler material.

[0088] By providing a filler material 14 between the first electronic device 12 and the circuit board 11, the connection reliability between the first electronic device 12 and the circuit board 11 is improved. Since the filler material 14 is in contact with the insulating material 15, the insulating material 15 can prevent the filler material 14 from contacting the second electronic device 13. Since the elastic modulus of the insulating material 15 can be smaller than that of the filler material 14, the stress on the second electronic device 13 is reduced when the circuit board assembly 10 is subjected to impact, which helps to improve the reliability of the second electronic device 13.

[0089] In some embodiments, the insulating material 15 may include acrylic resin. Figure 11 is a structural diagram of the insulating material and filler material after curing in a method for preparing a circuit board assembly according to an embodiment of this application. Figure 11(a) shows the structural diagram of the insulating material after pre-curing; Figure 11(b) shows the structural diagram of the insulating material and filler material after thermosetting.

[0090] As shown in Figure 11(a), after the insulating material 15 is applied to the second electronic device 13 and before the filler material 14 is applied between the first electronic device 12 and the circuit board 11, the preparation method of the circuit board assembly 10 further includes: pre-curing the insulating material 15 by an ultraviolet curing process. The ultraviolet curing equipment 40 can be used to pre-cur the insulating material 15. This arrangement facilitates the pre-shaping of the insulating material 15 and improves the encapsulation effect of the insulating material 15 on the second electronic device 13.

[0091] As shown in Figure 11(b), after the filler material 14 is placed between the first electronic device 12 and the circuit board 11, the fabrication method of the circuit board assembly 10 further includes: thermosetting the insulating material 15 and the filler material 14. This arrangement allows the insulating material 15 and the filler material 14 to be cured in a single step, simplifying the curing steps and improving the fabrication efficiency of the circuit board assembly 10.

[0092] In some embodiments, the insulating material 15 may include epoxy resin. The epoxy resin may be thermosetting. Figure 12 is a structural diagram of the insulating material and filler material after curing in another method for preparing a circuit board assembly according to an embodiment of this application. Figure 12(a) shows the structural diagram after the insulating material is applied outside the second electronic device; Figure 12(b) shows the structural diagram after the insulating material and filler material have been thermoset.

[0093] As shown in Figure 12(a), after the insulating material 15 is placed on the second electronic device 13, pre-curing of the insulating material 15 is unnecessary. Furthermore, as shown in Figure 12(b), after the filler material 14 is placed between the first electronic device 12 and the circuit board 11, the fabrication method of the circuit board assembly 10 further includes thermosetting the insulating material 15 and the filler material 14. Through these modifications, the insulating material 15 and the filler material 14 can be cured in a single step, which simplifies the curing steps of the insulating material 15 and the filler material 14 and further improves the fabrication efficiency of the circuit board assembly 10. Moreover, since pre-curing of the insulating material 15 is unnecessary, the processing cost of the circuit board assembly 10 is reduced.

[0094] This application also provides a method for preparing a circuit board assembly 10, 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 flowchart of another method for preparing a circuit board assembly 10 provided in this application. Figure 14 is a structural diagram of another method for preparing a circuit board assembly provided in this application after curing the insulating material and the filling material. Referring to Figure 5 and in conjunction with Figures 13 and 14, the method for preparing the circuit board assembly 10 may include steps S201-S204.

[0095] S201. The first electronic device is soldered to the first side of the circuit board through the first bump.

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

[0097] In this embodiment of the 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. An insulating material is provided on the second electronic device so that the insulating material covers the second electronic device and the solder terminals of the second electronic device are exposed outside the insulating material.

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

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

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

[0102] S203. The second electronic device is soldered to the first side of the circuit board through the second bump. The second electronic device and the first electronic device are arranged along the first direction, which is perpendicular to the thickness direction of the circuit board.

[0103] In some embodiments, the structure of the second protrusion 32 can be as shown in Figures 6 to 9, and will not be described again here. The above arrangement ensures that the second electronic device 13 and the first electronic device 12 are disposed on the same side of the circuit board 11.

[0104] Figure 14(b) shows the structure after the second electronic device 13 is soldered onto the circuit board. The second electronic device 13 can be soldered to the first side A of the circuit board 11 through the second bump 32.

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

[0106] S204. A filler material is provided between the first electronic device and the circuit board so that the filler material wraps around the first bump, the filler material is in contact with the isolation material, and the elastic modulus of the isolation material is less than that of the filler material.

[0107] Figure 14(c) shows the structure after a filler material is placed between the first electronic device and the circuit board. Referring to Figure 14(c), placing a filler material 14 between the first electronic device 12 and the circuit board 11 improves the reliability of the connection between them. Since the filler material 14 is in contact with the insulating material 15, the insulating material 15 prevents the filler material 14 from contacting the second electronic device 13. Because the elastic modulus of the insulating material 15 can be smaller than that of the filler material 14, the stress on the second electronic device 13 is reduced when the circuit board assembly 10 is subjected to impact, which improves the reliability of the second electronic device 13.

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

[0109] When the insulating material 15 includes acrylic resin, after step S202 and before step S203, the insulating material 15 can be pre-cured by a UV curing process. For example, after the insulating 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 insulating material 15 can be pre-cured by a UV curing process.

[0110] The above-mentioned settings facilitate the pre-forming of the insulating material 15 and improve the encapsulation effect of the insulating material 15 on the second electronic device 13.

[0111] In step S204 above, after the filler material 14 is placed between the first electronic device 12 and the circuit board 11, the insulating material 15 and the filler material 14 can be thermo-cured.

[0112] The above settings enable the isolation material 15 and the filler material 14 to be cured and molded in one step, which simplifies the curing steps of the isolation material 15 and the filler material 14 and improves the manufacturing efficiency of the circuit board assembly 10.

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

[0114] In step S203 above, when the insulating material 15 comprises B-Stage type epoxy resin, and the second electronic device 13 is soldered to the first side A of the circuit board 11 via the second bump 32, the insulating material 15 is heated and melted, causing the insulating material 15 to wrap around the second bump 32. For example, during the soldering process between the second electronic device 13 and the circuit board 11, the soldering temperature is transferred to the insulating material 15, causing the insulating material 15 to melt, and the melted insulating material 15 wraps around the second bump 32.

[0115] In step S204 above, after the filler material 14 is placed between the first electronic device 12 and the circuit board 11, the insulating material 15 and the filler material 14 can be thermo-cured.

[0116] With the above arrangement, the insulating material 15 can wrap the second electronic device 13 and the second protrusion 32 at the same time, which helps to further prevent the second protrusion 32 from contacting the filling material 14. The stress on the second protrusion 32 is reduced, which helps to improve the reliability of the second electronic device 13.

[0117] In some embodiments, the insulating material 15 may include epoxy resin. The epoxy resin may be thermosetting.

[0118] When the insulating material 15 includes a thermosetting epoxy resin, after step S202 and before step S203, the insulating material 15 can also be thermosetting. For example, after the insulating 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 insulating material 15 can be thermosetting.

[0119] By thermosetting the insulating material 15, the insulating material 15 is shaped and prevented from flowing and obstructing the welding terminals of the second electronic device 13.

[0120] In step S204 above, after the filler material 14 is placed between the first electronic device 12 and the circuit board 11, the filler material 14 can be thermo-cured.

[0121] The above settings allow the filling material 14 to be cured and molded, which helps to improve the connection reliability between the first electronic device 12 and the circuit board 11.

[0122] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A wiring board assembly, characterized by comprising: The circuit board assembly comprises: a circuit board; a first electronic device soldered to a first side of the circuit board by a first bump; a filling material at least partially located between the first electronic device and the circuit board, and the filling material wrapping the first bump; a second electronic device soldered to the first side of the circuit board by a second bump, the second electronic device arranged along a first direction with the first electronic device, the first direction being perpendicular to a thickness direction of the circuit board; an isolation material wrapping at least part of the second electronic device, the isolation material being in contact with the filling material, and the isolation material having an elastic modulus smaller than that of the filling material.

2. The wiring board assembly according to claim 1, wherein The second electronic device comprises a body, a coil and an electrode, the electrode being covered on a surface of the body, the coil extending from an inside of the body to the surface of the body and being in contact with the electrode; The isolation material wraps a part of the electrode in contact with the coil.

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

4. The wiring board assembly according to any one of claims 1 to 3, characterized by, The isolation material also wraps the second bump.

5. The wiring board assembly according to any one of claims 1 to 4, characterized by, The isolation material comprises acrylic resin or epoxy resin.

6. The wiring board assembly according to any one of claims 1-5, wherein, The filling material comprises epoxy resin and filling particles embedded in the epoxy resin.

7. A method of manufacturing a wiring board assembly including a wiring board, a first electronic device, and a second electronic device, characterized by, A method for manufacturing the circuit board assembly comprises: soldering a first electronic device to a first side of a circuit board by a first bump; soldering a second electronic device to the first side of the circuit board by a second bump, the second electronic device arranged along a first direction with the first electronic device, the first direction being perpendicular to a thickness direction of the circuit board; providing an isolation material on the second electronic device so that the isolation material wraps at least part of the second electronic device; providing a filling material between the first electronic device and the circuit board so that the filling material wraps the first bump, the filling material being in contact with the isolation material, and the isolation material having an elastic modulus smaller than that of the filling material.

8. The method of manufacturing a wiring board assembly according to claim 7, wherein The isolation material comprises acrylic resin; After the step of providing the isolation material on the second electronic device, and before the step of providing the filling material between the first electronic device and the circuit board, the method further comprises: pre-curing the isolation material by a UV curing process; After the step of providing the filling material between the first electronic device and the circuit board, the method further comprises: heat-curing the isolation material and the filling material.

9. The method of manufacturing a circuit board assembly according to claim 7, wherein, The isolation material comprises epoxy resin; After the step of providing the filling material between the first electronic device and the circuit board, the method further comprises: heat-curing the isolation material and the filling material.

10. A method of manufacturing a wiring board assembly including a wiring board, a first electronic device, and a second electronic device, characterized by, A method for manufacturing the circuit board assembly comprises: soldering a first electronic device to a first side of a circuit board by a first bump; providing an isolation material on a second electronic device so that the isolation material wraps the second electronic device, and a soldering terminal of the second electronic device is exposed outside the isolation material; soldering the second electronic device to the first side of the circuit board through a second bump, the second electronic device being arranged along a first direction with the first electronic device, the first direction being perpendicular to a thickness direction of the circuit board; providing a filling material between the first electronic device and the circuit board, so that the filling material wraps the first bump, the filling material being in contact with an isolation material, the isolation material having an elastic modulus less than that of the filling material. The isolation material comprises acrylic resin.

11. The method of manufacturing a circuit board assembly according to claim 10, wherein, After the step of providing the isolation material on the second electronic device, and before the step of soldering the second electronic device to the first side of the circuit board through a second bump, the method further comprises: pre-curing the isolation material through a UV curing process; After the step of providing the filling material between the first electronic device and the circuit board, the method further comprises: thermally curing the isolation material and the filling material. The isolation material comprises epoxy resin.

12. The method of manufacturing a circuit board assembly according to claim 10, wherein The step of soldering the second electronic device to the first side of the circuit board through a second bump further comprises that the isolation material is melted by heat so that the isolation material wraps the second bump. After the step of providing the filling material between the first electronic device and the circuit board, the method further comprises: thermally curing the isolation material and the filling material. The isolation material comprises epoxy resin.

13. The method of manufacturing a circuit board assembly according to claim 10, wherein After the step of providing the isolation material on the second electronic device, and before the step of soldering the second electronic device to the first side of the circuit board through a second bump, the method further comprises: thermally curing the isolation material; After the step of providing the filling material between the first electronic device and the circuit board, the method further comprises: thermally curing the filling material. A battery for supplying power to the first electronic device and the second electronic device of the circuit board assembly according to any one of claims 1-6.

14. An electronic device, comprising: ​

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