CN117135824A

CN117135824A - Circuit board assembly and manufacturing method thereof

Info

Publication number: CN117135824A
Application number: CN202210553944.6A
Authority: CN
Inventors: 朱贤江; 李卫祥
Original assignee: Peng Ding Polytron Technologies Inc; Avary Holding Shenzhen Co Ltd; Qing Ding Precision Electronics Huaian Co Ltd
Current assignee: Peng Ding Polytron Technologies Inc; Avary Holding Shenzhen Co Ltd; Qing Ding Precision Electronics Huaian Co Ltd
Priority date: 2022-05-20
Filing date: 2022-05-20
Publication date: 2023-11-28
Also published as: TW202348094A

Abstract

A method of manufacturing a circuit board assembly includes forming a shield, and disposing a heat conductive paste and an electronic component in the shield such that the shield, the heat conductive paste, and the electronic component form a package module. The method further includes mounting the package module on the bonding pad of the first circuit substrate to electrically connect the electronic component to the bonding pad. The method further includes disposing a second circuit substrate on the first circuit substrate after mounting the package module on the pads of the first circuit substrate, wherein the second circuit substrate laterally surrounds the package module. Therefore, the protection of the electronic element is improved, and the heat dissipation efficiency of the electronic element is improved, so that the reliability and the efficiency of the circuit board assembly are improved. The application also provides a circuit board assembly.

Description

Circuit board assembly and manufacturing method thereof

Technical Field

The present application relates to a circuit board assembly and a manufacturing method thereof, and more particularly to a circuit board assembly with embedded electronic components and a manufacturing method thereof.

Background

With the trend of electronic products, the technology of circuit board assemblies with embedded electronic components has been increasingly favored in the industry, wherein the technology has tended to be rapid, highly reliable, multifunctional, miniaturized and high-performance. Embedding the electronic component in the circuit board can reduce the wiring area and the wiring length to meet the development trend of the electronic product.

Therefore, the reliability and performance of the circuit board assembly of the embedded electronic component are improved to the greatest extent by each industry.

Disclosure of Invention

According to some embodiments of the present application, a method of manufacturing a circuit board assembly includes forming a shield, and disposing a heat conductive paste and an electronic component in the shield such that the shield, the heat conductive paste, and the electronic component form a package module. The method for manufacturing the circuit board assembly further comprises the step of installing the packaging module on the connecting pad of the first circuit substrate, wherein the electronic element is electrically connected with the connecting pad. The method of manufacturing the circuit board assembly further includes, after mounting the package module on the pads of the first circuit substrate, disposing a second circuit substrate on the first circuit substrate, wherein the second circuit substrate laterally surrounds the package module.

In some embodiments, after mounting the package module on the pads of the first circuit substrate and before disposing the second circuit substrate on the first circuit substrate, an opening is formed in the second circuit substrate, such that the package module is embedded in the second circuit substrate through the opening during disposing the second circuit substrate on the first circuit substrate.

In some embodiments, disposing the heat-conductive paste and the electronic component in the shield includes distributing the heat-conductive paste in the shield and placing the electronic component in the shield. The heat-conducting glue is interposed between the shield and the electronic component such that the heat-conducting glue electrically isolates the shield from the electronic component.

In some embodiments, forming the shield includes providing a metal block and forming an opening in the metal block, wherein the opening extends from an outer surface of the metal block to an interior.

According to some embodiments of the present application, a circuit board assembly includes a first circuit substrate, a package module, and a second circuit substrate. The first circuit substrate comprises a connecting pad. The packaging module is arranged on the first circuit substrate and comprises an electronic element, a shielding cover and heat-conducting glue. The electronic element is arranged on the connecting pad of the first circuit substrate. The shield encloses the electronic component. The heat conducting glue is arranged between the electronic component and the shielding cover. The second circuit substrate is arranged on the first circuit substrate and transversely surrounds the packaging module.

In some embodiments, the circuit board assembly further includes solder disposed between the package module and the pads and connecting the package module and the pads.

In some embodiments, the circuit board assembly further includes an insulator disposed between and over the pads and including pattern openings, wherein solder is distributed in the pattern openings.

In some embodiments, the electronic component has a first surface to which the bond pads are attached. The heat-conducting glue does not cover the first surface, but completely covers other surfaces of the electronic component. The shield does not surround the first surface but completely surrounds other surfaces of the electronic component.

In some embodiments, the shield has an outer surface and an inner surface. A portion of the outer surface directly contacts the second circuit substrate. The inner surface directly and fully contacts the heat conductive glue.

In some embodiments, the circuit board assembly further includes a metal layer disposed on the shield and directly contacting another portion of the outer surface.

Embodiments of the present application provide a circuit board assembly and a method of manufacturing the same. By embedding the shielding cover and the electronic element in the circuit board, the protection of the electronic element is improved and the heat dissipation efficiency of the electronic element is increased. Therefore, the reliability and the efficiency of the circuit board assembly of the embedded electronic element can be improved.

Drawings

The following embodiments are to be read in conjunction with the accompanying drawings to provide a clear understanding of the aspects of the application. It should be noted that the various features are not drawn to scale according to industry standard practices. In fact, the dimensions of the various features may be arbitrarily expanded or reduced for clarity of discussion. Moreover, like reference numerals designate like elements.

Fig. 1, 2, 3 and 4 are perspective views of a circuit board assembly at various stages of manufacture in accordance with some embodiments of the present application.

Fig. 5, 6 and 7A are cross-sectional views of a circuit board assembly at various stages of manufacture in accordance with some embodiments of the present application.

Fig. 7B is a top view of a circuit board assembly at various stages of manufacture in accordance with some embodiments of the present application.

Fig. 8A is a cross-sectional view of a circuit board assembly at various stages of manufacture in accordance with some embodiments of the present application.

Fig. 8B is a cross-sectional view of a circuit board assembly at various stages of manufacture in accordance with some embodiments of the present application.

Fig. 8C is a top view of a circuit board assembly at various stages of manufacture in accordance with some embodiments of the present application.

Fig. 9 and 10 are cross-sectional views of a circuit board assembly at various stages of manufacture in accordance with some embodiments of the present application.

Detailed Description

When an element such as a layer, film, region or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements present. As used herein, "connected" may refer to physical and/or electrical connection. Furthermore, "electrically connected" or "coupled" may mean that there are other elements between the elements.

Moreover, relative terms such as "lower" or "bottom" and "upper" or "top" may be used herein to describe one element's relationship to another element as illustrated. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. For example, if the device in one of the figures is turned over, elements described as being on the "lower" side of other elements would then be oriented on the "upper" side of the other elements. Thus, the exemplary term "lower" may include both "lower" and "upper" orientations, depending on the particular orientation of the figure. Similarly, if the device in one of the figures is turned over, elements described as "below" or "over" other elements would then be oriented "above" the other elements. Thus, the exemplary terms "below" or "above" can encompass both an orientation of above and below.

As used herein, "about," "approximately," or "approximately" includes both the values and average values within an acceptable deviation of the particular values determined by one of ordinary skill in the art, taking into account the particular number of measurements and errors associated with the measurements in question (i.e., limitations of the measurement system). For example, "about" may mean within one or more standard deviations of the values.

Unless defined otherwise, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present application and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

With the trend of electronic products, the technology of circuit board assemblies with embedded electronic components has been increasingly favored in the industry, wherein the technology has tended to be rapid, highly reliable, multifunctional, miniaturized and high-performance. Embedding the electronic component in the circuit board not only reduces the wiring area, but also shortens the wiring length, contributing to reducing the loss of signal transmission. When the electronic component is embedded in a specified position of the circuit board, the electronic component is usually exposed in the embedded area of the circuit board without additional processing, and is easily damaged by external force, or undesirable phenomena of electromagnetic interference (electromagnetic interference, EMI) occur. Meanwhile, improvement of heat dissipation efficiency of the circuit board assembly with embedded electronic components is also demanded. The application provides a circuit board assembly with embedded electronic elements and a manufacturing method thereof, which can improve the protection of the electronic elements and the heat dissipation efficiency, thereby improving the reliability and the efficiency of the circuit board assembly with embedded electronic elements.

It should be noted that when the following embodiments are illustrated or described as a series of operations or events, the order of the description of the operations or events should not be limited, unless otherwise noted. For example, some operations or events may take on a different order, some may occur concurrently, some may not be required to be taken, and/or some may be repeated, than the present application. Also, the actual process may require additional operations before, during, or after each step. Thus, the present application may briefly explain some of the additional operations.

Referring to fig. 1, fig. 1 is a perspective view of a circuit board assembly at one stage of manufacture in a method of manufacturing a circuit board assembly according to some embodiments of the application. First, in operation S10, a metal block 100 having a first surface S1 and a second surface S2 opposite to the first surface S1 is provided. The metal block 100 may include copper, nickel, iron, cobalt, tin, chromium, titanium, aluminum, manganese, zinc, lead, other metals, alloys of the foregoing, or combinations thereof. For example, the metal block 100 may comprise an alloy of copper and nickel. The shape and size of the metal block 100 may be adjusted according to product design and process conditions. In some embodiments, the metal block 100 may be a cuboid.

Referring to fig. 2, fig. 2is a perspective view of a circuit board assembly at one of its stages of manufacture in accordance with some embodiments of the present application. Next, in operation S12, an opening 200 is formed in the metal block 100 to form a shield 202, wherein the opening 200 extends from an outer surface of the metal block 100 to an inside of the metal block 100. For example, the opening 200 may extend from the first surface S1 to the interior of the metal block 100 in a direction toward the second surface S2. The shield 202 may have an outer surface 202ES and an inner surface 202IS, wherein the space surrounded by the inner surface 202IS substantially coincides with the opening 200.

In some embodiments, shield 202is an integrally formed structure. In other words, the shield 202is not formed from a combination of various components. Accordingly, the internal structure of the shield 202is free of connection interfaces or seams, thereby ensuring that the shield 202 provides electromagnetic shielding (electromagnetic shielding).

Methods of forming the openings 200 may include fishing, mechanical or laser drilling, etching, other suitable techniques, or combinations thereof. It should be noted that the methods described above with respect to forming shield 202 in fig. 1 and 2 are by way of example only and not limitation. Other methods of forming shield 202, such as die casting, etc., are within the scope of the present application.

Referring to fig. 3, fig. 3 is a perspective view of a circuit board assembly at one of its manufacturing stages in a method of manufacturing a circuit board assembly according to some embodiments of the application. Next, in operation S14, the electronic component 300 is placed into the shield case 202. In other words, the electronic component 300 is filled into the opening 200. The electronic device 300 may have one or more pads 302 disposed on the active surface 300AS of the electronic device 300. In some embodiments, when placing the electronic component 300 to the shield 202, the pads 302 (or active surfaces 300 AS) face outward, i.e., the pads 302 (or active surfaces 300 AS) face opposite to the direction D1 in which the electronic component 300 moves to the shield 202.

Since the size of the opening 200 IS designed to be larger than the size of the electronic component 300 in operation S12 (refer to fig. 2), a gap may exist between the electronic component 300 and the inner surface 202IS of the shield case 202 after the electronic component 300 IS placed in the shield case 202.

In some embodiments, in operation S14, the heat-conducting glue 304 may be distributed in the shielding can 202, and then the electronic component 300 IS placed in the shielding can 202, so that the bottom of the electronic component 300 IS separated from the inner surface 202IS of the shielding can 202 by the heat-conducting glue 304. Thus, the thermally conductive paste 304 may prevent the electronic component 300 from contacting the shield 202. In some embodiments, the thermal conductive paste 304 has an electrically insulating effect and may be referred to as an insulating thermal conductive paste.

The electronic component 300 may be a passive component such as a capacitor, inductor, resistor, or the like. The electronic component 300 may be an active component, such as a transistor. Alternatively, the electronic device 300 may include active devices and passive devices, such as an Integrated Circuit (IC) having active devices and passive devices, but the application is not limited thereto.

The material of the thermal conductive paste 304 may include epoxy, polyimide (PI), polyamide-imide (PAI), other suitable materials, or a combination thereof. In some embodiments, the thermally conductive paste 304 is flowable, and the thermally conductive paste 304 may be cured by a subsequent process (e.g., heat treatment or light treatment).

Referring to fig. 4, fig. 4 is a perspective view of a circuit board assembly at one of its stages of manufacture in accordance with some embodiments of the present application. Next, in operation S16, the heat-conductive glue 304 and the electronic component 300 are disposed in the shielding can 202, such that the shielding can 202, the heat-conductive glue 304 and the electronic component 300 form the package module 400. In some embodiments, disposing the thermally conductive paste 304 and the electronic component 300 in the shield 202 may include performing a curing process to cure the flowable thermally conductive paste 304 to set.

In the package module 400 shown in fig. 4, the electronic component 300 is surrounded by the shielding can 202, and the thermally conductive paste 304 is sandwiched between the electronic component 300 and the shielding can 202. In some embodiments, the inner surface 202IS (see fig. 2) of the shield 202 may directly and completely contact the thermally conductive paste 304.

As described above, since the size of the opening 200 has been designed to be larger than the size of the electronic component 300 in advance at the time of the aforementioned operation S12, a gap (air gap) exists between the lateral periphery of the electronic component 300 and the inner surface 202IS of the shield case 202. In some embodiments employing a flowable thermally conductive paste 304, after the electronic component 300 is disposed in the shield 202, the thermally conductive paste 304 may be extruded to flow, thereby filling the gap (air gap) between the electronic component 300 and the shield 202, so that the electronic component 300 does not directly contact the shield 202.

Since air is a poor conductor of heat, heat transfer is impeded, for example, from electronic component 300 to shield 202. In contrast, the heat conductive glue 304 has better heat conduction properties. Therefore, the heat-conducting glue 304 disposed between the electronic component 300 and the shielding case 202 can exhaust air, thereby increasing heat transfer and heat dissipation efficiency, and thus helping the performance of the electronic component 300.

In addition to conducting heat, in some embodiments in which the thermally conductive paste 304 has a dielectric material, the thermally conductive paste 304 between the shield 202 and the electronic component 300 may also electrically isolate the shield 202 from the electronic component 300 to reduce shorting.

When the amount of the thermally conductive paste 304 is insufficient, the thermally conductive paste 304 may not completely fill the gap between the electronic component 300 and the shield case 202. In this embodiment, the material of the heat-conducting glue 304 can be filled into the remaining gap between the electronic component 300 and the shielding case 202 again, so that the heat-conducting glue 304 completely fills the gap (air gap) between the electronic component 300 and the shielding case 202, and the heat-conducting glue 304 is completely sandwiched between the electronic component 300 and the shielding case 202, thereby ensuring the improvement of the heat dissipation efficiency.

The operation of disposing the thermally conductive paste 304 in the shield 202 may also include paste overflow removal. For example, the thermal conductive paste 304 may overflow on the active surface 300AS or the first surface S1, and a cleaning process may be performed to remove the overflow portion of the thermal conductive paste 304.

In this embodiment, the active surface 300AS of the electronic device 300 and the pads 302 are exposed. In other words, the shielding case 202 or the thermally conductive adhesive 304 does not cover the active surface 300AS of the electronic device 300 and the pads 302. In some embodiments, the thermally conductive paste 304 substantially completely covers other surfaces of the electronic component 300, regardless of the active surface 300AS of the electronic component 300. Likewise, the shield 202 substantially completely encloses the other surfaces of the electronic component 300, regardless of the active surface 300AS of the electronic component 300. In other words, in this embodiment, the shielding cover 202 can substantially completely shield other surfaces of the electronic component 300, thereby reducing electromagnetic interference between the electronic component 300 and other components (not shown), so as to improve signal quality.

Referring to fig. 5, fig. 5 is a cross-sectional view of a circuit board assembly at one of its stages of manufacture in accordance with some embodiments of the present application. Next, in operation S18, a first circuit substrate 500 is provided. The first circuit substrate 500 may include a first substrate layer 502, a first circuit layer 504, and a second circuit layer 506. The first circuit layer 504 may include one or more first pads 508 and one or more second pads 510, wherein the first pads 508 are spaced apart from each other, the second pads 510 are spaced apart from each other, and the first pads 508 and the second pads 510 are spaced apart from each other. The first circuit layer 504 also has a trench 512.

In some embodiments, the first pads 508 may provide a function of transmitting electrical signals. In some embodiments, the second pad 510 may not provide the function of transmitting electrical signals.

The material of the first substrate layer 502 may include a dielectric material, and the dielectric material may be formed of a polymer (poly) or a non-polymer (non-poly). For example, but not limited to, liquid crystal polymer (liquid crystal polymer, LCP), bismaleimide-triazine (BT), film (prepreg), inorganic filler-containing resin (e.g., ajinomoto Build-up Film, ABF), epoxy, polyimide (PI), or other resin materials. Furthermore, the material may also have fibers, such as glass fibers or Kevlar fibers (Kevlar fibers), to increase the strength of the first substrate layer 502. In some embodiments, the first substrate layer 502 may be formed of a photoimageable (photo-active) dielectric material or a photoactive (photo-active) dielectric material. The materials of the first circuit layer 504 and the second circuit layer 506 may include gold, silver, copper, nickel, tin, other suitable metals, or alloys of combinations of the foregoing.

Referring to fig. 6, fig. 6 is a cross-sectional view of a circuit board assembly at one of its stages of manufacture in accordance with some embodiments of the present application. Next, in operation S20, an insulator 600 is disposed on the first circuit substrate 500. Specifically, the insulator 600 is disposed between and over the first pads 508, and between the first pads 508 and the second pads 510. In some embodiments, the insulator 600 has a pattern opening 602.

The material of insulator 600 may include epoxy, polyimide, or other suitable solder resist ink material. Furthermore, additives such as hardeners or photoinitiators may be added to the aforementioned materials according to the process requirements or product design, but the present application is not limited to the above examples. In some embodiments, the material of the insulator 600 may be a thermoset solder resist ink. In other embodiments, the material of insulator 600 may be a photo-curable solder resist ink. The method of forming the insulator 600 having the pattern openings 602 may include a deposition process, an exposure and development process, an etching process, a curing process, other suitable processes, or any combination thereof. In some embodiments, the method of forming the insulator 600 with the pattern openings 602 may include screen printing (screen print) techniques.

Referring to fig. 7A and 7B, fig. 7A is a cross-sectional view of a circuit board assembly at one of the stages of manufacture in a method of manufacturing a circuit board assembly according to some embodiments of the application, and fig. 7B is a partial top view of fig. 7A according to some embodiments of the application. Next, as shown in fig. 7A, in operation S22, the package module 400 is disposed on the first circuit substrate 500. For example, the mounting (mount) package module 400 is mounted on the first and second pads 508 and 510 of the first circuit substrate 500. In some embodiments, the package module 400 of fig. 4 is turned upside down, and the electronic device 300 is mounted on the first pad 508 of the first circuit substrate 500, so that the pad 302 on the active surface 300AS of the electronic device 300 is connected to the first pad 508. After installation, the insulator 600 may contact (e.g., directly contact) the electronic component 300 and the thermally conductive paste 304.

Operation S22 further includes disposing solder 700 between the package module 400 and the first pads 508 to connect the package module 400 and the first pads 508 and fix the package module 400 on the first circuit substrate 500. In some embodiments, solder 700 directly contacts electronic component 300 (e.g., bond pad 302) and first bond pad 508, whereby electronic component 300 may be electrically connected to first bond pad 508 via solder 700.

As further described, solder 700 may be located in the space enclosed by insulator 600, bond pad 302, and first bond pad 508. In operation S20 (refer to fig. 6), the configured insulator 600 may define a location range of the solder 700. In other words, the solder 700 may be distributed in the pattern openings 602 of the insulator 600. Accordingly, the insulator 600 may electrically isolate adjacent solders 700, thereby reducing the likelihood of shorting.

The material of solder 700 may include aluminum, gold, silver, copper, tin, bismuth, nickel, or other metals, or combinations thereof. In some embodiments, solder 700 is solder paste (solder paste).

In some embodiments, the operation S22 further includes disposing an adhesive material 702 between the package module 400 and the second pad 510 to connect the package module 400 and the second pad 510, thereby enhancing the firmness of the package module 400 on the first circuit substrate 500. The adhesive material 702 may directly contact the shield 202 and the second pad 510. In some embodiments, the adhesive material 702 and the second pad 510 laterally surround the insulator 600.

The adhesive material 702 may include epoxy, PI, metallic material, or other suitable material. When the adhesive material 702 includes a metal material such as aluminum, gold, silver, copper, tin, bismuth, nickel, or other metals, or combinations thereof, the adhesive material 702, the second pad 510, and the shielding can 202 can jointly provide electromagnetic shielding effect to enhance electromagnetic shielding effect on the electronic component 300. In some further embodiments, the adhesive material 702 uses the same material as the solder 700.

In some embodiments where the second pads 510 do not function to transmit electrical signals and the adhesive material 702 comprises a metallic material, the grooves 512 separate the second pads 510 from other circuits by a distance sufficient to serve as a receiving space when the adhesive material 702 overflows, such that the overflowed adhesive material 702 does not contact the other circuits, thereby reducing the likelihood of a short circuit. In some embodiments, the trench 512 is located around the package module 400. For example, in the embodiment shown in fig. 7B, the trench 512 surrounds the package module 400.

Referring to fig. 8A, 8B and 8C, fig. 8A is a cross-sectional view of a circuit board assembly at one of the stages of manufacture in a method of manufacturing a circuit board assembly according to some embodiments of the application, fig. 8B is a cross-sectional view of a circuit board assembly at one of the stages of manufacture in a method of manufacturing a circuit board assembly according to some embodiments of the application, and fig. 8C is a partial top view of fig. 8B according to some embodiments of the application. Next, as shown in fig. 8A and 8B, in operation S24, a second circuit substrate 800 is disposed on the first circuit substrate 500, wherein the second circuit substrate 800 laterally surrounds the package module 400. The second circuit substrate 800 may include a second substrate layer 802, a prepreg 804, and a metal foil layer 806 that are laminated to one another.

Specifically, openings may be first formed in the second circuit substrate 800, such as in the second substrate layer 802, in the prepreg 804, and in the metal foil layer 806, as shown in fig. 8A, wherein each of the openings is larger than the size of the package module 400; then, the second substrate layer 802, the prepreg 804 and the metal foil layer 806 are stacked on the first circuit substrate 500, wherein the package module 400 is disposed in the second substrate layer 802, the prepreg 804 and the metal foil layer 806 due to the openings; subsequently, the second substrate layer 802, the prepreg 804, and the metal foil layer 806 are laminated to form a second circuit substrate 800 around the package module 400, as shown in fig. 8B.

The materials in the second circuit substrate 800 may be combined or laminated together by the prepreg 804, thereby forming the second circuit substrate 800. A prepreg 804 may be disposed around the second substrate layer 802. In some embodiments, the prepreg 804 laterally surrounds the encapsulation module 400. In a further embodiment, the semi-cured film 804 laterally surrounds and directly contacts the encapsulation module 400, as shown in fig. 8C, thereby enhancing the bonding force between the encapsulation module 400 and the second circuit substrate 800.

In other words, a portion, such as a lateral portion, of the outer surface 202ES (see fig. 2) of the shield 202 may directly contact the second circuit substrate 800. In contrast, another portion of the outer surface 202ES of the shield 202 may be exposed, such as the outer upper surface of the shield 202 in fig. 8B.

The semi-cured film 804 may include a flowable adhesive material, such that the flowable adhesive material is extruded during the assembly or lamination process of the second circuit substrate 800 and may be distributed in the grooves 512 (see fig. 7A), the space between the package module 400 and the substrate layer (e.g., the second substrate layer 802), or other receivable areas. For example, a prepreg 804 may be distributed between the package module 400 and the metal foil layer 806. Alternatively, the prepreg 804 may be distributed between the encapsulation module 400 and the second substrate layer 802. In some embodiments, as shown in fig. 8B, the lateral outer surface of the encapsulation module 400 may completely and directly contact the prepreg 804, thereby enhancing the bonding force between the encapsulation module 400 and the second circuit substrate 800. In some further embodiments, the adhesive material 702 and the second pad 510 directly contact the prepreg 804.

It should be noted that while the embodiment of fig. 8A and 8B only show a single second substrate layer 802 and metal foil layer 806, the number of layers can be adjusted depending on the actual process or product design and remain within the scope of the present application.

In some embodiments, after operation S22 (see fig. 7A) is completed, operation S24 is performed. Because the encapsulation module 400 is already mounted on the first circuit substrate 500, in operation S24 after operation S22, openings are first formed in the second substrate layer 802, openings are formed in the prepreg 804 and openings are formed in the metal foil layer 806, as shown in fig. 8A, wherein the size of each opening may be equal to or larger than the size of the encapsulation module 400, so that the encapsulation module 400 may be disposed in the second substrate layer 802, the prepreg 804 and the metal foil layer 806 by each opening during the process of disposing the second substrate layer 802, the prepreg 804 and the metal foil layer 806 on the first circuit substrate 500, and then embedded in the second circuit substrate 800.

When the above operation is adopted, since the electronic component 300 is designed to be embedded in the shielding case 202, the shielding case 202 can be used as a protective cover for the electronic component 300 in the subsequent process, so that the electronic component 300 is prevented from being damaged due to extrusion or collision of external force, and the reliability of the electronic component 300 can be improved. Furthermore, the electronic components 300 are designed to be embedded in the shielding case 202 to be combined together into a single component (i.e., the package module 400), thereby simplifying the operations in the subsequent processes (e.g., the operation of mounting the package module 400 on the first circuit substrate 500).

In fig. 8B, operation S24 may include performing a polishing process on the second circuit substrate 800 to remove an excess portion of the prepreg 804 located on the top surface 400T of the package module 400 or on the top surface 806T of the metal foil layer 806. After the grinding process, the top surface 400T of the package module 400 can be coplanar with the top surface 806T of the metal foil layer 806. In some embodiments, the top surface 400T of the encapsulation module 400, the top surface 806T of the metal foil layer 806, and the top surface 804T of the prepreg 804 are coplanar with one another.

The material of the second substrate layer 802 may include a dielectric material, and the dielectric material may be polymeric or non-polymeric. For example, LCP, BT, film, resin containing inorganic fillers (e.g., ABF), epoxy, PI, or other resin materials, but the present application is not limited to the above examples. In some embodiments, the second substrate layer 802 may be formed of a photoimageable dielectric material or a photosensitive dielectric material. The material of the metal foil layer 806 can include gold, silver, copper, nickel, tin, other suitable metals, or alloys of combinations of the foregoing. In some embodiments, the metal foil layer 806 can be a copper foil layer.

Referring to fig. 9, fig. 9 is a cross-sectional view of a circuit board assembly at one of its stages of manufacture in accordance with some embodiments of the present application. Next, in operation S26, the metal layer 900 is disposed on the package module 400. Specifically, the metal layer 900 is disposed on the shield 202. In some embodiments, metal layer 900 directly contacts shield 202. For example, the metal layer 900 may directly contact a portion of the outer surface 202ES (see fig. 2) of the shield 202, where such portion is an exposed portion in fig. 8A, such as an outer upper surface of the shield 202. Therefore, heat generated by the electronic component 300 can be conducted to the metal layer 900 through the heat conductive paste 304 and the shielding can 202.

In some embodiments, metal layer 900 is only connected to shield 202. Furthermore, the metal layer 900 may not provide a function of transmitting an electrical signal. In some embodiments, trenches 902 are formed around the metal layer 900 to isolate the metal layer 900, thereby electrically isolating the metal layer 900 from other circuits.

In operation S26, a conductive via 904 or a conductive blind via 906 may also be formed in the first circuit substrate 500 or the second circuit substrate 800. The conductive blind via 906 may be electrically connected to the first pad 508.

Methods of forming the conductive via 904 or the conductive blind via 906 may include mechanical or laser drilling (drill) processes, exposure development processes, etching processes, electroplating (electro) processes, electroless (electroless plating) processes, sputtering (sputter) processes, evaporation (evapration) processes, other suitable processes, or combinations thereof. The conductive via 904 may be solid or hollow, and the hollow conductive via 904 may be filled with an insulating material in a subsequent process.

Referring to fig. 10, fig. 10 is a cross-sectional view of a circuit board assembly at one of its stages of manufacture in accordance with some embodiments of the present application. Next, in operation S28, a solder mask layer 1000 is disposed on the first circuit substrate 500 or the second circuit substrate 800, wherein the solder mask layer 1000 does not cover the metal layer 900 on the package module 400 to facilitate heat dissipation. For example, the heat generated by the electronic component 300 can be conducted to the metal layer 900 through the heat-conducting glue 304 and the shielding case 202, and then the exposed metal layer 900 can discharge the heat to the outside by heat radiation, thereby improving the heat dissipation efficiency.

The material of the solder mask 1000 may include epoxy, polyimide, or other suitable material. Furthermore, additives such as hardeners or photoinitiators may be added to the aforementioned materials according to the process requirements or product design, but the present application is not limited to the above examples. In some embodiments, the material of the solder mask 1000 may be a thermosetting solder mask ink. In other embodiments, the material of the solder mask 1000 may be a photo-curable solder mask ink. The formation of the solder mask layer 1000 may include a deposition process, an exposure and development process, an etching process, a curing process, other suitable processes, or any combination thereof. In some embodiments, the solder mask layer 1000 may be formed using a screen printing technique.

To this end, a circuit board assembly of embedded electronic component 300 is substantially manufactured.

In view of the foregoing, embodiments of the present application provide a circuit board assembly and a method of manufacturing the same. The electronic element is embedded in the shielding cover, and then the combined structure of the electronic element and the shielding cover is embedded in the circuit board together, so that the process of the circuit board assembly is simplified. In addition, in the process, the shielding cover can protect the electronic element from damage caused by external force, so that the reliability of the electronic element and a subsequently formed circuit board assembly is improved. Furthermore, the shielding cover made of metal can have electromagnetic shielding effect, and can also increase the heat dissipation efficiency of the electronic element, thereby improving the performance of the circuit board assembly embedded with the electronic element.

The foregoing generally illustrates the features of several embodiments of the present application so that those skilled in the art may more readily understand the present application. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures or processes for carrying out the same purposes and/or obtaining the same advantages of the embodiments of the present application. It will be understood by those skilled in the art that the foregoing and equivalent structures do not depart from the spirit and scope of the application, and that they can be modified, altered, substituted, and altered without departing from the spirit and scope of the application.

[ symbolic description ]

100 metal block

200 opening

202 shielded enclosure

202ES, outer surface

202IS: inner surface

300 electronic component

300AS active surface

302, pad

304, heat-conducting glue

400 packaging module

400T top surface

500 first circuit substrate

502 first substrate layer

504 first circuit layer

506 second circuit layer

508 first pad

510 second pad

512 groove

600 insulating member

602 pattern openings

700 solder

702 adhesive material

800 second circuit substrate

802 second substrate layer

804 semi-cured film

804T top surface

806 Metal foil layer

806T top surface

900 metal layer

902 groove

904 conductive via

906 conductive blind holes

1000 solder mask layer

D1 direction

S10-S28, operation.

Claims

1. A method of manufacturing a circuit board assembly, comprising:

forming a shielding cover;

configuring heat-conducting glue and electronic elements in the shielding cover, so that the shielding cover, the heat-conducting glue and the electronic elements form a packaging module;

mounting the packaging module on a connecting pad of a first circuit substrate, wherein the electronic element is electrically connected with the connecting pad; and

after the packaging module is arranged on the connecting pad of the first circuit substrate, a second circuit substrate is arranged on the first circuit substrate, wherein the second circuit substrate transversely surrounds the packaging module.

2. The method of manufacturing a circuit board assembly according to claim 1, wherein an opening is formed in the second circuit substrate after the packaging module is mounted on the pads of the first circuit substrate and before the second circuit substrate is disposed on the first circuit substrate, such that the packaging module is embedded in the second circuit substrate through the opening during the disposing of the second circuit substrate on the first circuit substrate.

3. The method of manufacturing a circuit board assembly of claim 1, wherein disposing the thermally conductive paste and the electronic component in the shield comprises:

distributing the heat conducting glue in the shielding case; and

and placing the electronic component into the shielding cover, wherein the heat-conducting glue is arranged between the shielding cover and the electronic component, so that the heat-conducting glue electrically isolates the shielding cover and the electronic component.

4. The method of manufacturing a circuit board assembly of claim 1, wherein forming the shield comprises:

providing a metal block; and

an opening is formed in the metal block, wherein the opening extends from an outer surface of the metal block to an interior.

5. A circuit board assembly, comprising:

a first circuit substrate including a pad;

a package module disposed on the first circuit substrate, comprising:

an electronic element arranged on the connecting pad;

a shield case surrounding the electronic component; and

the heat-conducting glue is clamped between the electronic element and the shielding cover; and

the second circuit substrate is arranged on the first circuit substrate and transversely surrounds the packaging module.

6. The circuit board assembly of claim 5, further comprising:

solder disposed between the package module and the bonding pad and connecting the package module and the bonding pad.

7. The circuit board assembly of claim 6, further comprising:

and an insulating member disposed between and over the pads and including pattern openings, wherein the solder is distributed in the pattern openings.

8. The circuit board assembly of claim 5, wherein

The electronic element is provided with a first surface, and the first surface is connected with the connecting pad;

the heat-conducting glue does not cover the first surface, but completely covers other surfaces of the electronic component; and

the shield does not surround the first surface but completely surrounds other surfaces of the electronic component.

9. The circuit board assembly of claim 5, wherein the shield has an outer surface and an inner surface, a portion of the outer surface directly contacting the second circuit substrate and the inner surface directly and fully contacting the thermally conductive paste.

10. The circuit board assembly of claim 9, further comprising a metal layer disposed on the shield and directly contacting another portion of the outer surface.