Patent ID: 12245358

DETAILED DESCRIPTION

It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale, and the proportions of certain parts may be exaggerated to better illustrate details and features of the present disclosure.

The term “comprising,” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series, and the like.

FIG.14illustrates a flowchart of a manufacturing method of a circuit board100in accordance with an embodiment. The method is provided by way of embodiments, as there are a variety of ways to carry out the method. Each block shown inFIG.14represents one or more processes, methods, or subroutines carried out in the method. Furthermore, the illustrated order of blocks can be changed. Additional blocks may be added or fewer blocks may be utilized, without departing from this disclosure. The method can begin at block 1.

Block 1, referring toFIG.1, a strippable carrier10is provided, which includes a carrier body11and a release film12formed on the carrier body11.

In at least one embodiment, the carrier body11may be a glass plate or a ceramic plate. The release film12may be a PET release film.

Block 2, referring toFIG.2, a copper-clad substrate20is formed on the release film12. The copper-clad substrate20includes a copper foil layer21and a first insulating layer22formed on the copper foil layer21. The copper foil layer21is sandwiched between the first insulating layer22and the release film12.

In at least one embodiment, the first insulating layer22may include a thermal conductive and electrical insulating material selected from a group consisting of polyimide (PI), thermoplastic polyimide (TPI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene (PE), polyvinyl chloride (PVC), and any combination thereof.

Block 3, referring toFIG.3, a heat dissipation medium layer23is formed on the first insulating layer22to obtain an intermediate body25.

In at least one embodiment, the heat dissipation medium layer23includes an electrical insulating resin and a thermal conductive filler. The electrical insulating resin includes epoxy resin, BT resin, polyphenylene ether, polyimide, and any combination thereof. The thermal conductive filler includes nano silicon oxide powders, nano silicon carbide powders, nano aluminum oxide powders, and any combination thereof.

Block 4, referring toFIG.4, a groove251is defined in the intermediate body25, and the groove251extends through the heat dissipation medium layer23and a portion of the first insulating layer22. At least one first hole252is further defined on a bottom surface of the groove251, causing the copper foil layer21to be partially exposed from the first hole252. Furthermore, two second holes253are also defined in the intermediate body25. Each second hole253extends through the heat dissipation medium layer23and the first insulating layer22, causing the copper foil layer21to be partially exposed from the second hole253.

In at least one embodiment, each of the groove251, the first holes252, and the second hole253is formed by mechanical drilling or laser etching.

Block 5, referring toFIG.5, a soldering flux30is formed in the first hole252and electrically connected to the copper foil layer21. Furthermore, a conductive rubber is formed in each of the two second holes253to form a shielding column31, and the two shielding columns31is electrically connected to the copper foil layer21. The two shielding columns31and a portion of the copper foil layer21between the two shielding columns31cooperatively form a shielding space32.

In at least one embodiment, the conductive rubber includes an adhesive and metal particles dispersed in the adhesive. The adhesive may be silicone, silicone oxide, and any combination thereof. The metal particles may be silver, copper, and aluminum.

Block 6, referring toFIG.6, an electronic component200having two pins201is formed in the groove251. The soldering flux30is melted by welding, causing the pins201of the electronic component200to electrically connect to the copper foil layer21.

In at least one embodiment, a height H of the electronic component200is not greater than a depth D of the groove251. That is, the electronic component200is totally disposed in the shielding space32.

By disposing the electronic component200in the shielding space32, an electromagnetic shielding effect is realized, and an overall thickness of the circuit board100is also reduced. Furthermore, since the soldering flux30is formed in each first hole252, the first hole252can avoid short circuit generated by a flow of the melted soldering flux30, and also can avoid an external spaced required to receiving the soldering flux30, thus further reducing the overall thickness of the circuit board100.

Block 7, referring to7, a second insulating layer33is formed on the heat dissipation medium layer23. The second insulating layer33further fills a gap between the groove251and the electronic component200. Thus, the electronic component200is encapsulated and fixed in the groove251. The first insulating layer22, the second insulating layer33, and the heat dissipation medium layer23cooperatively form an insulating substrate34. The electronic component200is embedded in the insulating substrate34.

Block 8, referring toFIG.8, two first slots331and one second slot332are defined in the second insulating layer33, and the electronic component200is partially exposed from each of the two first slots331and the second slot332. Then, a circuit substrate35is obtained.

The two first slots331are spaced from each other. The second slot332is disposed between the two first slots331.

Block 9, referring toFIG.9, a metal base layer40is formed on the second insulating layer33. The metal base layer40also fills in each of the two first slots331to form a thermal conductive base layer41, and also fills in the second slot332to form an electric conductive base layer42.

In at least one embodiment, the metal base layer40is a copper layer formed by sputtering.

Block 10, referring toFIG.10, a first phase change material43is formed on the thermal conductive base layer41, so that heat generated by the electronic component200can be transferred to the thermal conductive base layer41and the first phase change material43. That is, the first phase change material43is thermally connected to the electronic component200.

The first phase change material43can conduct the heat along a thickness direction A of the insulating substrate34. The thermal conductive base layer41also functions as a container for receiving the first phase change material43, which can prevent a leakage of the first phase change material43. In other embodiments, the metal base layer40may also be omitted. That is, the first phase change material43is directly formed in the two first slots331and in contact with the electronic component200.

In at least one embodiment, the first phase change material43includes a solid-liquid phase change material such as paraffin, advanced fatty acid, polyolefin, and any combination thereof. In other embodiments, the first phase change material43may also include conductive powders, such as copper powders, aluminum powders, graphite powders, and any combination thereof. The first phase change material43is soften and become liquid after being heated, which can store heat energy. A portion of the stored heat energy may be transferred to the outside environment, and the remaining portion of the heat energy may be used to maintain the temperature of the insulating substrate34and the temperature of the electronic component200that can then work normally.

Block 11, referring toFIG.11, an electroplated layer44is formed on the metal base layer40through electroplating. The electroplated layer44is also formed on the electric conductive base layer42to form a conductive body45. The conductive body45and the electric conductive base layer42cooperatively form an electric conductive column46. The electric conductive column46is electrically connected to a surface of the electronic component200away from the soldering flux30.

Block 12, referring toFIG.12, the release film12is removed to expose the copper foil layer21. Then, the electroplated layer44and the metal base layer40are etched to form a first wiring layer50, and the copper foil layer21is etched to form a second wiring layer51.

The first wiring layer50is electrically connected to a surface of the electronic component200through the electric conductive column46. The first wiring layer50is further thermally connected to the electronic component200through the first phase change material43and the thermal conductive base layer41. The second wiring layer51is connected to another surface of the electronic component200through the soldering flux30. The second wiring layer51includes a number of wiring portions511spaced from each other. Two of the wiring portions511are connected to the two shielding columns31. A wiring slot512is formed between two adjacent wiring portions511, and the first insulating layer22is partially exposed from the wiring slot512.

Block 13, referring toFIG.13, a second phase change material60fills in some adjacent wiring slots512. Then, a solder mask61is formed on the second wiring layer51, which covers the second phase change material60and the wiring portions511.

The second phase change material60thermally connects some adjacent wiring portions511together to form a heat dissipation zone S. The heat dissipation zone S can correspond to the electronic component200. The heat dissipation zone S can increase a heat dissipation area and improve the heat dissipation efficiency of the electronic component200. In at least one embodiment, the second phase change material60includes paraffin, higher fatty acid, polyolefin, and any combination thereof.

In the manufacturing method of the circuit board100according to the present disclosure, the electronic component200is embedded in the insulating substrate34, and the thermal conduction between the electronic component200and the first wiring layer50is realized through the first phase change material43. Thus, the thermal conductivity of the electronic component200along the thickness direction A is improved. Moreover, by filling the wiring slots512of the second wiring layer51with the second phase change material60, the thermal conduction between the wiring portions511and the electronic component200is achieved. Thus, the heat dissipation area and the heat dissipation efficiency of the electronic component200are improved.

Referring toFIG.13, a circuit board100is also provided according to an embodiment of the present disclosure. The circuit board100includes a circuit substrate35, a first phase change material43, and a first wiring layer50. The circuit substrate35includes an insulating substrate34and an electronic component200embedded in the insulating substrate34. A number of first slots331are defined in the insulating substrate34and spaced from each other. The electronic components200are partially exposed from the first slots331. The first phase change material43is formed in each of the first slots331. The first phase change material43is thermally connected to the electronic component200. The first wiring layer50is formed on the insulating substrate34and covers the first slots331. The first phase change material43is thermally connected to the first wiring layer50.

In at least one embodiment, the circuit board100further includes a second wiring layer51and a second phase change material60. The second wiring layer51is formed on the insulating substrate34, and the insulating substrate34is between the first wiring layer50and the second wiring layer51. The second wiring layer51includes a number of wiring portions511spaced from each other. A wiring slot512is formed between two adjacent wiring portions511, and the insulating substrate34is partially exposed from the wiring slot512. The electronic component200is electrically connected to the second wiring portion511. The second phase change material60is formed in some adjacent wiring slots512. The second phase change material60thermally connects some adjacent wiring portions511together to form a heat dissipation zone S. The heat dissipation zone S can correspond to the electronic component200.

In at least one embodiment, the circuit board100further includes a thermal conductive base layer41formed in each of the first slots331. The first phase change material43is formed on the thermal conductive base layer41. The thermal conductive base layer41thermally connects the first phase change material43to the electronic component200.

In at least one embodiment, the circuit board100further includes two shielding columns31formed in the insulating substrate34and spaced from each other. The two shielding columns31and the second wiring layer51between the two shielding columns31cooperatively form a shielding space32. The electronic component200is formed in the shielding space32, thus improving the anti-interference ability of the electronic component200against external electromagnetic waves.

It is to be understood, even though information and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the present embodiments, the disclosure is illustrative only; changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the present embodiments to the full extent indicated by the plain meaning of the terms in which the appended claims are expressed.