CN117528896A

CN117528896A - Circuit board and manufacturing method thereof

Info

Publication number: CN117528896A
Application number: CN202210890384.3A
Authority: CN
Inventors: 李成佳; 陈伯元
Original assignee: Hongqisheng Precision Electronics Qinhuangdao Co Ltd; Avary Holding Shenzhen Co Ltd
Current assignee: Hongqisheng Precision Electronics Qinhuangdao Co Ltd; Avary Holding Shenzhen Co Ltd
Priority date: 2022-07-27
Filing date: 2022-07-27
Publication date: 2024-02-06
Also published as: TWI822223B

Abstract

A circuit board comprises a first electronic component, a solidified liquid metal composite layer, a circuit structure and a second electronic component. The solidified liquid metal composite layer covers the first electronic element and covers the upper surface and the side surface of the first electronic element. The circuit structure surrounds the first electronic component and the solidified liquid metal composite layer. The second electronic element is arranged on the upper surface of the first electronic element and is electrically connected with the first electronic element through the solidified liquid metal composite layer. The present application also provides a method of manufacturing a circuit board. The circuit board and the method for manufacturing the circuit board can shield and protect the first electronic element by using the solidified liquid metal composite layer, improve the heat dissipation efficiency of the first electronic element, simplify the process and the number of elements, improve the packaging precision and density and improve the structural reliability of the circuit board.

Description

Circuit board and manufacturing method thereof

Technical Field

The application relates to a circuit board and a manufacturing method thereof.

Background

High density and high reliability are trends in the development of circuit boards, so the embedded technology of electronic components is increasingly favored by the industry, not only the volume can be reduced, but also the line length can be shortened, the parasitic inductance can be reduced, and the density and the electrical connection efficiency of the circuit boards can be improved.

However, with the increasingly dense device configuration, how to improve the heat dissipation efficiency of the electronic device, the quality of the electrical connection, and the structural reliability is a problem to be solved.

Disclosure of Invention

According to some embodiments of the present application, a circuit board includes a first electronic component, a solidified liquid metal composite layer, a circuit structure, and a second electronic component. The first electronic component has an upper surface, a lower surface opposite to the upper surface, and a plurality of side surfaces connecting the upper surface and the lower surface. The solidified liquid metal composite layer covers the first electronic element and covers the upper surface and the side surface of the first electronic element. The circuit structure surrounds the first electronic component and the solidified liquid metal composite layer. The second electronic element is arranged on the upper surface of the first electronic element and is electrically connected with the first electronic element through the solidified liquid metal composite layer.

In some embodiments, the material of the solidified liquid metal composite layer includes a liquid metal and a high molecular polymer.

In some embodiments, the solidified liquid metal composite layer includes a first portion, a second portion, and a third portion. The first portion entirely covers a side surface of the first electronic component and extends to cover an upper surface of the portion. The second part is arranged on the upper surface of the first electronic element and is electrically connected with the first electronic element and the second electronic element. The third portion is disposed under the lower surface of the first electronic component, wherein the first portion, the second portion, and the third portion are spaced apart from each other.

In some embodiments, the circuit board further includes a conductive bonding structure and a third electronic component. The conductive bonding structure is arranged under the first electronic element. The third electronic element is arranged under the first electronic element and is electrically connected with the first electronic element through the conductive joint structure.

In some embodiments, the conductive engagement structure includes a first conductive member having a plurality of grooves and a second conductive member. A first conductive member having a plurality of grooves, including a third portion of the solidified liquid metal composite layer, a plurality of conductive pad layers disposed under the third portion and spaced apart from each other via the grooves; and a conductive layer disposed under the conductive pad layer and extending to cover the recess. The second conductive member comprises a conductive post extending vertically and a connecting pad extending transversely, wherein the connecting pad contacts the conductive post with a first surface and contacts the third electronic element with a second surface opposite to the first surface, and the conductive post is inserted into the groove of the first conductive member.

According to some embodiments of the present application, a method of manufacturing a circuit board includes providing a substrate, wherein the substrate includes a base material and a first conductive layer disposed on the base material; providing a circuit structure surrounding the substrate; disposing a first electronic component on the first conductive layer, wherein the first electronic component has an upper surface and a lower surface opposite to the upper surface; filling the liquid metal compound on the first conductive layer until the top surface of the liquid metal compound is higher than the upper surface of the first electronic element; solidifying the liquid metal composite; and arranging a second electronic element on the solidified liquid metal composite layer.

In some embodiments, after the step of forming the solidified liquid metal composite layer, further comprising: forming a first opening in the solidified liquid metal composite layer on the upper surface; setting an insulating layer on the solidified liquid metal composite layer on the upper surface and filling the first opening; forming a second opening extending to the insulating layer and exposing the solidified liquid metal composite layer; filling the second opening with a liquid metal compound and covering part of the insulating layer; and solidifying the liquid metal compound filling the second opening and the insulating layer of the covering part.

In some embodiments, the method further comprises: setting a part of the solidified liquid metal composite layer below the lower surface of the first electronic element so as to connect the first conductive layer and the first electronic element; removing the substrate; and disposing a third electronic component under the first electronic component such that the third electronic component is electrically connected to the first electronic component via a conductive bonding structure, wherein the conductive bonding structure comprises a portion of the solidified liquid metal composite layer.

In some embodiments, the step of disposing the third electronic component under the first electronic component includes: removing a portion of the first conductive layer to form a plurality of conductive pad layers under a portion of the solidified liquid metal composite layer, and the conductive pad layers being spaced apart from each other by a plurality of first grooves; arranging a second conductive layer under the conductive cushion layer and extending to conformally cover the first grooves to form a plurality of second grooves, so that the second conductive layer, the conductive cushion layer and the part of the solidified liquid metal composite layer jointly form a first conductive piece with the second grooves; providing a third electronic element and a second conductive piece arranged on the third electronic element, wherein the second conductive piece comprises a conductive column extending vertically and a connecting pad extending transversely, and the connecting pad contacts the conductive column with a first surface and contacts the third electronic element with a second surface opposite to the first surface; and arranging a third electronic element under the first electronic element, so that the conductive column of the second conductive element is inserted into the second groove of the first conductive element.

In some embodiments, the step of solidifying the liquid metal composite comprises heating the liquid metal composite at a temperature of 60 ℃ to 200 ℃.

Embodiments of the present application provide a circuit board and a method of manufacturing the same. By using the setting of the solidified liquid metal composite layer, better electric connection quality is realized for the electronic element (such as the first electronic element), and the structural reliability of the circuit board and the heat dissipation efficiency of the electronic element are improved.

Drawings

The following methods are read in conjunction with the accompanying drawings to provide a clear understanding of the aspects of the present 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. 1A-1M are cross-sectional views of a circuit board at various stages of manufacture according to 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 "beneath" other elements would then be oriented "above" the other elements. Thus, the exemplary terms "below" or "beneath" 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.

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

Please refer to fig. 1A. First, a substrate 110 is provided, wherein the substrate 110 includes a substrate 112 and a conductive layer 114 disposed on the substrate 112.

In some embodiments, the material of the substrate 112 may include a liquid crystal polymer (liquid crystal polymer, LCP), a bismaleimide-triazine (BT), a resin containing an inorganic filler (e.g., ABF (Ajinomoto Build-up Film) resin or epoxy), a Polyimide (PI), such as a thermoplastic polyimide (thermoplastic polyimide, TPI), a polyethylene terephthalate (polyethylene terephthalate, PET), a polyethylene naphthalate (polythylene naphthalate, PEN), a polyurethane (PU, such as a thermoplastic polyurethane (thermoplastic polyurethane, TPU)), other suitable materials, derivatives of the above, or any combination of the above. In some embodiments, the material of the conductive layer 114 is gold, silver, copper, nickel, tin, other suitable metals, or any combination thereof.

Next, please refer to fig. 1B. A portion of the conductive layer 114 is removed to form an opening H0 and a remaining portion 114P of the conductive layer 114 on the substrate 112, and the remaining portions 114P are spaced apart from each other through the opening H0. In some embodiments, the step of removing portions of the conductive layer 114 may include bailing, drilling (e.g., laser drilling or mechanical drilling), etching, stripping, other suitable methods, or combinations thereof. In one embodiment, portions of the conductive layer 114 are removed by etching, wherein the etchant used etches the conductive layer 114 faster than the substrate 112. Thus, the substrate 112 is substantially unaffected by the etching.

Next, please refer to fig. 1C. An insulating layer 122 is disposed on the substrate 112 and surrounds the remaining portion 114P. Next, the line structure CL is disposed on the insulating layer 122 and also surrounds the remaining portion 114P.

In some embodiments, the material of the insulating layer 122 may include a high molecular polymer, such as epoxy (epoxy), polyimide (PI), such as Thermoplastic Polyimide (TPI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyurethane (PU, e.g., thermoplastic Polyurethane (TPU)), other suitable materials, derivatives thereof, or any combination thereof.

In some embodiments, the insulating layer 122 and the line structure CL are both spaced apart from the remaining portion 114P via the opening H1. In some embodiments, the line structure CL is a multilayer line structure obtained via build-up (build-up). For example (not shown), a substrate (e.g., the substrate 112), a conductive layer (e.g., the conductive layer 114), and a metal layer (e.g., the copper layer) may be sequentially formed to obtain a first circuit structure, and then further, a second circuit structure is formed on the first circuit structure, and the first circuit structure and the second circuit structure are separated by an insulation layer, so on, thereby forming a multi-layer circuit structure.

Next, please refer to fig. 1D. The filling layer 132 is disposed in the opening H0 and the opening H1. Next, the first electronic element E1 is disposed on the remaining portion 114P of the conductive layer 114. In some embodiments, the material of the fill layer 132 includes a dielectric material, such as a photoimageable dielectric material (photo imageable dielectric, PID).

In some embodiments, the first electronic element E1 may be a passive element (e.g., resistor, capacitor, and inductor) or an active element (e.g., transistor). Alternatively, the first electronic device E1 may include an active device and a passive device, such as an integrated circuit (integrated circuit, IC) having an active device and a passive device, but the application is not limited thereto.

In some embodiments, the filling layer 132 fills all of the openings H0 and H1, and the upper surface 132a of the filling layer 132 may be flush with the upper surface 122a of the insulating layer 122. In some embodiments, the first electronic element E1 may include a plurality of metal pads M1, wherein the metal pads M1 may be located on the upper surface E1a and under the lower surface E1b of the first electronic element E1.

The metal pad M1 disposed under the lower surface E1b can make the lower surface E1b of the first electronic component E1 not directly contact with the retaining portion 114P, so as to leave a gap between the lower surface E1b and the retaining portion 114P, and reserve a filling space for a subsequent liquid metal compound. In some embodiments, the first electronic element E1 and the circuit structure CL may be electrically connected (not shown). In addition, the material of the metal pad M1 may be gold, silver, copper, nickel, tin, other suitable metals, or any combination thereof.

Next, please refer to fig. 1E. The liquid metal compound is filled on the remaining portion 114P of the conductive layer 114 until the top surface (liquid level) of the liquid metal compound is higher than the upper surface E1a of the first electronic component E1. Next, the liquid metal composite is solidified to form a solidified liquid metal composite layer 140.

In some embodiments, the material of the liquid metal composite comprises a liquid metal (amorphous metal, or metallic glass) and a high molecular polymer. In some embodiments, the liquid metal composite is a liquid metal composite obtained by mixing single or multiple metal particles and a high polymer in a specific proportion and sufficiently fusing the additives in a low-temperature smelting mode, wherein the metal particles are in an amorphous state (commonly called liquid metal). In some embodiments, the liquid metal may be copper or copper alloy and the high molecular polymer may be a gel, a resin, or a combination thereof.

In some embodiments, a binder or diluent may be further included in the liquid metal composite to improve adhesion or flowability, or wax powder, spheroidal graphite, dispersing agent, foaming agent, leveling agent, or the like may be further included to improve dispersibility of the metal particles in the liquid metal composite.

In some embodiments, during the process of filling the liquid metal compound on the reserved portion 114P, the line structure CL may be used as a barrier, so that the liquid metal compound on the reserved portion 114P, the filling layer 132 and the insulating layer 122 can directly contact all surfaces (including the upper surface E1a, the lower surface E1b and the side surface E1 c) of the first electronic component E1 and the sidewall CLs of the line structure CL. In some embodiments, the liquid metal compound covers the entire side surface E1c and the entire upper surface E1a and the entire lower surface E1b that are not in contact with the metal pad M1, thereby covering the entire first electronic component E1 and connecting the remaining portion 114P and the first electronic component E1.

Thereafter, the liquid metal composite may be solidified. In the step of forming the solidified liquid metal composite layer 140, the liquid metal composite (e.g., 60 ℃, 100 ℃, 150 ℃, 200 ℃ or a temperature in any of the foregoing ranges) is heated at a temperature of 60 ℃ to 200 ℃ so that the high molecular polymer in the liquid metal composite is completely solidified to form the solidified liquid metal composite layer 140. In some embodiments, the liquid metal composite may be cured by a stepwise temperature-increasing bake, for example, by heating the liquid metal composite to 20 ℃ every half hour, so that the liquid metal composite is heated uniformly, and the curing effect of the liquid metal composite is improved.

It is emphasized that the solidified liquid metal composite layer 140 has light, strong and bright characteristics and has better ductility, corrosion resistance, and abrasion resistance than existing metals.

Next, please refer to fig. 1F. The portion of the solidified liquid metal composite layer 140 located on the upper surface E1a is removed. Next, an insulating layer 124 is disposed on the solidified liquid metal composite layer 140, and build-up is performed on the insulating layer 124, so as to sequentially form a substrate 116 and a conductive layer 118 on the insulating layer 124. In some embodiments, the material of the insulating layer 124 may be the same as or similar to that of the insulating layer 122 (see fig. 1C), which is not described herein.

In some embodiments, the step of removing the portion of the solidified liquid metal composite layer 140 located on the upper surface E1a includes forming an opening H2 in the solidified liquid metal composite layer 140 such that the remaining portions 142 and other portions 144 of the solidified liquid metal composite layer 140 may be spaced apart from each other via the opening H2. In some embodiments, a laser may be used to remove portions of the solidified liquid metal composite layer 140 located on the upper surface E1a to form the opening H2.

In some embodiments, disposing the insulating layer 124 on the solidified liquid metal composite layer 140 includes disposing the insulating layer 124 on the portion 142 and the other portion 144 of the solidified liquid metal composite layer 140 and filling the opening H2.

Next, please refer to fig. 1G (please refer to fig. 1F for assistance). The substrate 112 under the reserved portion 114P is removed. Specifically, the step of removing the substrate 112 under the reserved portion 114P includes removing the entire substrate 112, thereby exposing the insulating layer 122, the filling layer 132, and the reserved portion 114P.

Next, please refer to fig. 1H. A portion of the remaining portion 114P is removed (please refer to fig. 1G in addition) to form a plurality of conductive pad layers CP under the other portion 144 of the solidified liquid metal composite layer 140, and the conductive pad layers CP are spaced apart from each other by the grooves A0. Next, the conductive layer 150 is disposed under the conductive pad layers CP and extends to cover the grooves A0.

In some embodiments, the material of the conductive layer 150 is gold, silver, copper, nickel, tin, other suitable metals, or alloys of combinations thereof. In some embodiments, the conductive pad layer CP and the metal pad M1 are made of the same material, and the metal pad M1 and the conductive layer 150 are made of different materials, for example, the conductive pad layer CP and the metal pad M1 are made of copper, and the conductive layer 150 is made of gold.

In some embodiments, conductive pad layer CP directly contacts lower surface 144b of other portion 144, and lower surface CPb of conductive pad layer CP is higher than lower surface 132b of filler layer 132. In some embodiments, conductive layer 150 is conformally disposed from conductive pad layer CP along recess A0, thereby further forming recess A1 at recess A0.

Next, please refer to fig. 1I. The conductive layer 118, the substrate 116, and the insulating layer 124 over the other portion 144 of the solidified liquid metal composite layer 140 are removed to form an opening H3. In addition, the filling layer 132 and other portions 144 (please refer to fig. 1H) located above the filling layer 132 and in direct contact with the filling layer 132 are removed, and the opening H4 is formed, such that the other portions 144 are separated into a portion 144A that completely covers the side surface E1c of the first electronic element E1 and extends to cover the upper surface E1a of the portion, and a portion 144B disposed under the lower surface E1B of the first electronic element E1 via the opening H4. Thus, the portion 144B, the metal pad M1, the conductive pad layer CP, and the conductive layer 150 collectively form a conductive member CU1 having a recess A1.

In some embodiments, the solidified liquid metal composite layer 140 (portions 142, 144A, and 144B) encapsulates at least 80% or more of the surface area of the first electronic element E1 (i.e., the sum of the surface areas of the upper surface E1a, the lower surface E1B, and the side surfaces E1 c), which may better shield and protect the first electronic element E1.

In some embodiments, a laser is used to remove the conductive layer 118, the substrate 116, and the insulating layer 124 over the other portions 144 of the solidified liquid metal composite layer 140, and to remove the filler layer 132 and the other portions 144 that are over the filler layer 132 and in direct contact with the filler layer 132.

Next, please refer to fig. 1J. The metal layer ML is disposed in the opening H3 such that the metal layer ML directly contacts the portion 144A, and the filler layer 134 is disposed on the conductive layer 118. The metal layer ML is connected to the portion 144A of the solidified liquid metal composite layer 140, which can assist in transferring heat of the first electronic element E1, improving a heat dissipation effect of the first electronic element E1, and assisting in electrically connecting the first electronic element E1 with other circuit structures (not shown).

In some embodiments, the metal layer ML is extendedly disposed over the conductive layer 118. In some embodiments, the metal layer ML and the filler layer 134 are separated by a gap SP and are not in direct contact. In some embodiments, disposing the filler layer 134 on the conductive layer 118 includes forming an opening H4 in the conductive layer 118, and disposing the filler layer 134 to fill the opening H4 such that the filler layer 134 is in direct contact with the substrate 116 and extends over the conductive layer 118. In some embodiments, the openings H4 are substantially aligned with the openings H2 in a vertical direction (Z-axis) such that portions 142 are substantially aligned in the vertical direction (Z-axis) between the conductive layers 118 adjacent to the openings H4 to promote accuracy of subsequent opening placement and wire connection.

Next, please refer to fig. 1K. An opening H5 is formed, wherein the opening H5 extends to the fill layer 134, the conductive layer 118, the substrate 116, and the insulating layer 124, exposing a portion 142 of the solidified liquid metal composite layer 140. Next, the opening H5 is filled with the liquid metal compound and covered with the filling layer 134. Next, the liquid metal composite is solidified to form a portion 146 of the solidified liquid metal composite layer 140 (e.g., using a solidification scheme similar to that of fig. 1E), such that the portion 146 is in direct contact with the portion 142. Next, the metal pad M2 is disposed on the lower surface E2b of the second electronic element E2, and the second electronic element E2 is disposed on the portion 146 in such a manner that the metal pad M2 is in direct contact with the portion 146, so that the first electronic element E1 and the second electronic element E2 are electrically connected through the metal pad M1, the portion 142, the portion 146 and the metal pad M2.

It should be emphasized that, compared with the existing via hole forming step, at least via hole pretreatment, via hole surface metallization, via hole electroplating or blind hole electroplating and other processes are required, the method of directly filling the liquid metal compound in the opening H5 and then solidifying the liquid metal compound layer 140 into the portion 146 is simpler and simpler, and the number of components can be simplified, thereby improving the packaging precision and density. In addition, the material of the solidified liquid metal composite layer 140 of the present application has better ductility, corrosion resistance, and abrasion resistance than existing metals.

On the other hand, compared to the manner of directly contacting the portion 142 with the existing metal (e.g. copper) (e.g. forming the existing via hole on the portion 142), the portions 142 and 146 of the present application are directly contacted, and better electrical connection quality can be achieved through the design of the same material.

In some embodiments, the step of forming the portion 146 of the solidified liquid metal composite layer 140 includes removing a portion of the portion 146 overlying the filler layer 134 to form a plurality of spaced apart metal posts 146A, thereby reducing the surface area of the portion 146 in contact with the filler layer 134 to reduce parasitic capacitance. In some embodiments, the projection area of the upper surface 146Aa of the metal pillar 146A contacting the metal pad M2 along the vertical direction (Z axis) projected on the X-Y cross section is larger than the projection area of the lower surface M2b of the metal pad M2 contacting the portion 146 along the vertical direction (Z axis) projected on the X-Y cross section, so as to improve the accuracy of the butt joint and the convenience of the operation, thereby improving the reliability of the connection. In some embodiments, the second electronic element E2 may be the same as or similar to the first electronic element E1, but the application is not limited thereto.

Next, please refer to fig. 1L. A third electronic element E3 is provided, and a conductive member CU2 disposed on the third electronic element E3. Next, the third electronic element E3 is disposed under the first electronic element E1, so that the third electronic element E3 is electrically connected to the first electronic element E1 through the conductive bonding structure CS (the conductive element CU1 and the conductive element CU 2).

In some embodiments, the conductive member CU2 includes a conductive post CU2A extending vertically (along the Z-axis direction) and a pad CU2B extending laterally (along the Y-axis direction), the pad CU2B contacting the conductive post CU2A with a first surface CU2Ba (at the dashed line) and contacting the third electronic element E3 with a second surface CU2Bb opposite the first surface CU2 Ba. That is, in the Y-Z cross section, the conductive member CU2 has a T shape. In some embodiments, the step of disposing the third electronic element E3 under the first electronic element E1 includes inserting the conductive post CU2A of the conductive member CU2 into the recess A1 formed by the conductive layer 150 of the conductive member CU1. In some embodiments, the conductive post CU2A and the pad CU2B are integrally formed.

It should be noted that, by the design that the conductive member CU2 is T-shaped in the Y-Z cross section and the conductive post CU2A is inserted into the groove A1 in the conductive layer 150, the contact area between the conductive member CU2 and the conductive member CU1 is increased, and the structural stability between the conductive member CU1 and the conductive member CU2 is improved, so that the efficiency of current transmission and the reliability of packaging are improved.

In some embodiments, conductive member CU2 and conductive layer 150 are connected to each other via conductive material 160. In some embodiments, the conductive material 160 may be solder, conductive paste, or conductive paste, wherein the conductive paste is, for example, anisotropic conductive paste (anisotropic conductive film, ACF).

Next, please refer to fig. 1M. The insulating layer 126A is provided to fill the space between the second electronic element E2 and the conductive layer 118, and the insulating layer 126B is provided to fill the space between the first electronic element E1 and the third electronic element E3, thereby completing the circuit board 100. In some embodiments, the material of insulating layer 126A or insulating layer 126B includes a dielectric material, such as a photoimageable dielectric material.

Specifically, the insulating layer 126A may directly contact the conductive layer 118, the filling layer 134, the portion 146 of the solidified liquid metal composite layer 140, the metal pad M2 and the second electronic element E2, and cover the filling layer 134, the portion 146 and the metal pad M2 and cover the entire upper surface 118a of the conductive layer 118. Thus, the filler layer 134, the portion 146, the metal pad M2, and the conductive layer 118 are not exposed.

On the other hand, the insulating layer 126B is in direct contact with the first electronic element E1, the third electronic element E3 and the conductive bonding structure CS, covers the entire conductive bonding structure CS, and covers the entire upper surface E3a of the third electronic element E3. Therefore, the insulating layers 126A and 126B are respectively used to cover the components (such as the metal pad M2) between the first electronic element E1 and the conductive layer 118 and the components (such as the conductive bonding structure CS) between the first electronic element E1 and the third electronic element E3, so as to prevent the components from being exposed and damaged by external force or being affected by external environment (such as moisture), thereby improving the structural reliability of the circuit board 100.

In view of the above, the embodiments of the present application provide a circuit board and a method for manufacturing the circuit board, which can shield and protect a first electronic component and improve the heat dissipation efficiency of the first electronic component by coating the upper surface and the side surface of the first electronic component with a solidified liquid metal composite layer. In addition, the first electronic element and the second electronic element are connected by using the solidified liquid metal composite layer, so that the conventional through hole electroplating and blind hole electroplating are replaced, the process and the number of elements can be simplified, and the packaging precision and density can be improved. It is also worth mentioning that, because the solidified liquid metal composite layer has better ductility, corrosion resistance and abrasion resistance compared with the existing metal, the application of the solidified liquid metal composite layer can simultaneously improve the structural reliability of the circuit board.

The foregoing has outlined features of several embodiments of the present application so that those skilled in the art may better 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 various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the present application and that the appended claims are intended to cover all such equivalents.

[ symbolic description ]

100 circuit board

110 substrate

112 substrate

114 conductive layer

114P reserved portion

116, substrate

118 conductive layer

118a upper surface

122. 124, 126A, 126B insulating layer

122a upper surface

132. 134 filling layer

132a, upper surface

132b lower surface

140 solidifying the liquid metal composite layer

142. 144A, 144B, 146 part of

144 other parts

144b lower surface

146A metal column

146Aa upper surface

150 conductive layer

160 conductive material

E1 first electronic component

E1a upper surface

E1b lower surface

E1c side surfaces

E2:second electronic component

E2b lower surface

E3:third electronic component

E3a.upper surface

A0, A1 groove

H0, H1, H2, H3, H4, H5: openings

M1, M2 metal pad

M2b lower surface

CL line structure

CLs side wall

CP conductive cushion layer

CPb lower surface

CS conductive joint structure

CU1, CU2 conductive member

CU2A conductive column

CU2B pad

CU2Ba first surface

CU2Bb second surface

ML metal layer

SP, gap.

Claims

1. A circuit board, comprising:

a first electronic component having an upper surface, a lower surface opposite to the upper surface, and a plurality of side surfaces connecting the upper surface and the lower surface;

solidifying the liquid metal composite layer, coating the first electronic element, and covering the upper surface and the side surface of the first electronic element;

a circuit structure surrounding the first electronic component and the solidified liquid metal composite layer; and

the second electronic element is arranged on the upper surface of the first electronic element and is electrically connected with the first electronic element through the solidified liquid metal composite layer.

2. The circuit board of claim 1, wherein the material of the solidified liquid metal composite layer comprises a liquid metal and a high molecular polymer.

3. The circuit board of claim 1, wherein the solidified liquid metal composite layer comprises:

a first portion entirely covering the side surface of the first electronic component and extending the upper surface of the covering portion;

a second portion disposed on the upper surface of the first electronic component and electrically connected to the first electronic component and the second electronic component; and

a third portion disposed under the lower surface of the first electronic component,

wherein the first portion, the second portion, and the third portion are spaced apart from one another.

4. The circuit board of claim 3, further comprising:

the conductive joint structure is arranged below the first electronic element; and

the third electronic element is arranged below the first electronic element and is electrically connected with the first electronic element through the conductive joint structure.

5. The circuit board of claim 4, wherein the conductive engagement structure comprises:

a first conductive member having a plurality of grooves, comprising:

said third portion of said solidified liquid metal composite layer;

a plurality of conductive pad layers disposed under the third portion and spaced apart from each other via the grooves; and

the conductive layer is arranged below the conductive cushion layer and extends to cover the groove; and

a second conductive member including a vertically extending conductive post and a laterally extending pad, wherein the pad contacts the conductive post with a first surface and contacts the third electronic component with a second surface opposite the first surface,

wherein the conductive post is inserted into the groove of the first conductive member.

6. A method of manufacturing a circuit board, comprising:

providing a substrate, wherein the substrate comprises a base material and a first conductive layer arranged on the base material;

providing a circuit structure surrounding the substrate;

disposing a first electronic component on the first conductive layer, wherein the first electronic component has an upper surface and a lower surface opposite to the upper surface;

filling a liquid metal compound on the first conductive layer until a top surface of the liquid metal compound is higher than the upper surface of the first electronic component;

solidifying the liquid metal composite to form a solidified liquid metal composite layer; and

and disposing a second electronic component on the solidified liquid metal composite layer.

7. The method of claim 6, wherein after the step of forming the solidified liquid metal composite layer, further comprising:

forming a first opening in the solidified liquid metal composite layer on the upper surface;

providing an insulating layer on the solidified liquid metal composite layer on the upper surface and filling the first opening;

forming a second opening extending to the insulating layer and exposing the solidified liquid metal composite layer;

filling the second opening with the liquid metal compound and covering a portion of the insulating layer; and

the liquid metal compound filling the second opening and the insulating layer covering the portion is solidified.

8. The method of claim 6, further comprising:

disposing a portion of the solidified liquid metal composite layer under the lower surface of the first electronic component, thereby connecting the first conductive layer and the first electronic component;

removing the substrate; and

and arranging a third electronic element under the first electronic element, so that the third electronic element is electrically connected with the first electronic element through a conductive joint structure, wherein the conductive joint structure comprises the part of the solidified liquid metal composite layer.

9. The method of claim 8, wherein disposing the third electronic component under the first electronic component comprises:

removing a portion of the first conductive layer to form a plurality of conductive spacers under the portion of the solidified liquid metal composite layer, and the conductive spacers being spaced apart from each other via a plurality of first grooves;

disposing a second conductive layer under the conductive pad layer and extending to conformally cover the first grooves, forming a plurality of second grooves, such that the second conductive layer, the conductive pad layer, and the portion of the solidified liquid metal composite layer together form a first conductive member having the second grooves;

providing a third electronic element and a second conductive member arranged on the third electronic element, wherein the second conductive member comprises a vertically extending conductive column and a laterally extending connection pad, and the connection pad contacts the conductive column with a first surface and contacts the third electronic element with a second surface opposite to the first surface; and

and arranging the third electronic element under the first electronic element, so that the conductive column of the second conductive piece is inserted into the second groove of the first conductive piece.

10. The method of claim 6, wherein the step of solidifying the liquid metal composite comprises heating the liquid metal composite at a temperature of 60 ℃ to 200 ℃.