CN114449742A - Manufacturing method of printed circuit board and printed circuit board - Google Patents

Abstract

The invention relates to the technical field of printed circuit boards, in particular to a manufacturing method of a printed circuit board and the printed circuit board. According to the manufacturing method of the printed circuit board and the printed circuit board, provided by the embodiment of the invention, the first through hole is formed in the first printed circuit sub-board; and arranging a conductive film on the inner wall of the first through hole and filling the first heat-conducting medium. Arranging a second through hole on the second printed circuit daughter board, and bonding and pressing the second printed circuit daughter board and the first printed circuit daughter board; and arranging a heat dissipation metal part in the second through hole, and arranging an insulating heat conduction layer at the bottom of the heat dissipation metal part so as to insulate the conductive film from the heat dissipation metal part. When the electrical element is installed, the electrical element can be directly installed at the first heat-conducting medium, the electrical element is over against the first heat-conducting medium, and then heat dissipation is carried out through the insulating heat-conducting layer and the heat dissipation metal part, the heat dissipation effect is good, the number of heat dissipation parts is effectively reduced, and the technical effect of miniaturization of the printed circuit board is achieved.

Description

Manufacturing method of printed circuit board and printed circuit board

Technical Field

The invention relates to the technical field of printed circuit boards, in particular to a manufacturing method of a printed circuit board and the printed circuit board.

Background

Printed circuit boards are important electronic components in circuit connection, and the trend of development thereof is mainly around miniaturization.

In the related art, the whole printed circuit board is made of high-frequency materials, the heat dissipation copper block penetrates through the printed circuit board along the thickness direction from the printed circuit board, and in the subsequent process of mounting electrical components, the electronic components can only be mounted by staggering the positions of the copper blocks. The copper block can only radiate the peripheral printed circuit board of the component in the radiating process.

However, the heat dissipation copper block has poor heat dissipation effect by performing heat dissipation on the periphery, and more copper blocks need to be arranged in order to achieve the required heat dissipation effect, thereby further increasing the size of the printed circuit board.

Disclosure of Invention

The invention provides a manufacturing method of a printed circuit board and the printed circuit board, which can effectively solve the above or other potential technical problems.

The invention provides a method for manufacturing a printed circuit board, which comprises the following steps: manufacturing a first printed circuit sub-board, wherein a plurality of first through holes are formed in the first printed circuit sub-board, and a heat dissipation area is formed in a part of the first printed circuit sub-board, which is provided with the plurality of first through holes: arranging a conductive film on the inner wall of the first through hole, and filling a first heat-conducting medium; manufacturing a second printed circuit sub-board, and forming a second through hole on the second printed circuit sub-board; bonding and pressing the second printed circuit daughter board and the first printed circuit daughter board through the insulating bonding layer, wherein the second through hole corresponds to the heat dissipation area; and arranging a heat dissipation metal part in the second through hole, and arranging an insulating heat conduction layer at the bottom of the heat dissipation metal part so as to insulate the conductive film from the heat dissipation metal part.

In an alternative embodiment according to the first aspect, the step of fabricating the first printed circuit daughter board further comprises: the first printed circuit daughter board is formed by mixing and pressing a printed circuit board and a high-frequency printed circuit slice; a plurality of first through holes are formed in the high-frequency printed circuit slicing area to form a heat dissipation area. It should be noted that the first printed circuit daughter board is formed by mixing and pressing a printed circuit board and a high-frequency printed circuit board slice, and a plurality of first through holes are formed in the high-frequency printed circuit slice region to form a heat dissipation region, that is, the high-frequency printed circuit slice is arranged at a position where an electrical component needs to be installed, and a common printed circuit board is adopted at other positions. Because the high-frequency material has high cost and is difficult to process, the high-frequency material is arranged at the part where the electrical element needs to be installed, so that the stable output of a high-frequency signal can be ensured; meanwhile, the problem that the whole plate is made of high-frequency materials so that the cost is high is avoided.

In an alternative embodiment according to the first aspect, the first printed circuit daughter board is formed by co-laminating a printed circuit board and a high frequency printed circuit slice, and the specific steps include: forming a third through hole with a preset shape in the first printed circuit board; pressing the high-frequency printed circuit slice matched with the shape of the third through hole into the third through hole to form a mixed-compression printed circuit board; and bonding the second printed circuit board with the mixed-compression printed circuit board through the prepreg to obtain the formed first printed circuit daughter board. Specifically, in the present embodiment, a third through hole having a preset shape is formed in the first printed circuit board; pressing the high-frequency printed circuit slice matched with the shape of the third through hole into the third through hole to form a mixed-voltage printed circuit board, so that the stable output of a high-frequency signal can be ensured; meanwhile, the problem that the whole plate is made of high-frequency materials so that the cost is high is avoided. And then, the second printed circuit board is bonded with the mixed-compression printed circuit board through the prepreg to obtain a formed first printed circuit daughter board, the thickness of the first printed circuit daughter board can be ensured by arranging the second printed circuit board, the space for internal wiring is further increased, the surface area of the whole first printed circuit daughter board is further reduced, and the miniaturization of the whole formed printed circuit board is realized.

In an alternative embodiment according to the first aspect, the first printed circuit board and the second printed circuit board each comprise a stack of electrically conductive layers and a first insulating layer arranged between adjacent electrically conductive layers; the high-frequency printed circuit slice comprises conducting layers which are arranged in a stacked mode and a second insulating layer which is arranged between the adjacent conducting layers, and the thickness of the first printed circuit board is the same as that of the high-frequency printed circuit slice. The first insulating layer and the second insulating layer are two different insulating layers and are made of different insulating materials, wherein the second insulating layer is a material capable of ensuring stable output of high-frequency signals. The thickness of the first printed circuit board is the same as that of the high-frequency printed circuit slice, so that the high-frequency printed circuit slice can be pressed into the first printed circuit board in a complete fit manner, and the stability of the whole structure is ensured.

In an alternative embodiment according to the first aspect, the second printed circuit sub-board includes conductive layers arranged in a stack and a third insulating layer arranged between adjacent conductive layers.

In an alternative embodiment according to the first aspect, the sum of the number of layers of the conductive layer of the first printed-circuit sub-board and the conductive layer of the second printed-circuit sub-board is not less than six layers. It should be noted that, the sum of the number of the conductive layers of the first printed circuit sub-board and the conductive layer of the second printed circuit sub-board is not less than six, so that the thickness of the whole printed circuit board formed by bonding the first printed circuit sub-board and the second printed circuit sub-board can be effectively ensured, the space of internal wiring is further ensured to be increased, the surface area of the whole printed circuit board is further reduced, and the miniaturization of the whole formed printed circuit board is realized.

In an alternative embodiment according to the first aspect, the second insulating layer is made of a high-frequency insulating material comprising: PPE resin, glass fiber cloth, aluminum oxide solid filler and an organic solvent; and/or the first insulating layer and the third insulating layer are made of the same material, and the first insulating layer comprises: epoxy resin, glass fiber cloth and silica solid filler; and/or the conductive layer comprises copper foil.

In an alternative embodiment according to the first aspect, the second printed circuit sub-board and the first printed circuit sub-board are bonded and pressed together by an insulating adhesive layer, and the method specifically includes:

placing a preset part in the second through hole, wherein the preset part is matched with the second through hole in shape, the insulating bonding layer is arranged between the top surface of the first printed circuit daughter board and the bottom surface of the second printed circuit daughter board around the heat dissipation area, after the second printed circuit daughter board is pressed with the first printed circuit daughter board, the top surface of the preset part is flush with the top surface of the second printed circuit daughter board, and the bottom surface of the preset part is abutted to the top surface of the heat dissipation area; the thickness of the preset part is the sum of the depth of the second through hole and the thickness of the insulating bonding layer; the preset is removed. It should be noted that, by setting the preset component, it is effectively avoided that, in the process of laminating the first printed circuit board and the second printed circuit board, the insulating adhesive layer arranged on the contact surface of the first printed circuit board and the second printed circuit board is pressed into the second through hole, which further results in the loss of the insulating adhesive layer arranged on the contact surface of the first printed circuit board and the second printed circuit board, and causes the unstable bonding phenomenon. Meanwhile, the situation that the heat dissipation metal part cannot be placed in the second through hole due to the fact that the insulating bonding layer is pressed into the second through hole is avoided. It should be further noted that the preset member is configured to match the shape of the second through hole, so as to ensure the stability of the second printed circuit daughter board structure during the pressing process. It should be further noted that the insulating adhesive layer is arranged between the top surface of the first printed circuit board and the bottom surface of the second printed circuit board around the heat dissipation area, after the second printed circuit board is pressed with the first printed circuit board, the top surface of the preset part is flush with the top surface of the second printed circuit board, and the bottom surface of the preset part is abutted to the top surface of the heat dissipation area. The insulating bonding layer can be prevented from being placed into the top surface of the heat dissipation area under the effect of the pressing force, and then the heat dissipation effect is influenced due to the fact that the heat dissipation metal part is thick in the subsequent arrangement.

In an optional embodiment according to the first aspect, a heat dissipation metal part is disposed in the second through hole, and an insulating and heat conducting layer is disposed at the bottom of the heat dissipation metal part, so that the conductive film is insulated from the heat dissipation metal part, and the specific steps include: liquid heat-conducting media are filled in the top surface of the heat dissipation area through the second through holes, the liquid heat-conducting media are solidified to form an insulating heat-conducting layer, and the thickness of the insulating heat-conducting layer is the same as that of the insulating bonding layer; and filling liquid metal into the second through hole, solidifying the liquid metal to form a heat dissipation metal part, and enabling the top surface of the heat dissipation metal part to be flush with the upper surface of the second printed circuit daughter board. It should be noted that the liquid heat-conducting medium is filled in the top surface of the heat dissipation area through the second through hole, and the liquid heat-conducting medium is an insulating heat-conducting layer after being cured, so that the heat dissipation effect can be ensured, and the conductive film can be prevented from being conducted with the heat dissipation metal part, so that the signal is abnormal. It should also be noted that, liquid metal is filled into the second through hole, the liquid metal forms a heat dissipation metal part after solidification, after the first printed circuit sub board and the second printed circuit sub board are pressed together, one end of the second through hole close to the first printed sub board is provided with an insulating and heat conducting layer, and at this moment, if the heat dissipation metal part is directly installed, the installation is difficult due to the existence of gas in the second through hole. The liquid metal is filled into the second through hole, and the liquid metal is solidified to form the heat dissipation metal part, so that the technical problem can be effectively solved. It should be further noted that the top surface of the heat dissipation metal part is flush with the upper surface of the second printed circuit board, so that the upper surface of the second printed circuit board is smooth, and the stability of the structure is guaranteed.

The second aspect of the present invention further provides a printed circuit board, which is manufactured by the above manufacturing method of a printed circuit board, and includes a first printed circuit sub-board and a second printed circuit sub-board, which are stacked, where the first printed circuit sub-board has a heat dissipation area, the first printed circuit sub-board in the heat dissipation area is provided with a plurality of first through holes, the inner wall of each first through hole is provided with a conductive film, and each first through hole is provided with a first heat-conducting medium; and a second through hole is formed in the second printed circuit sub-board corresponding to the heat dissipation area, a heat dissipation metal part is arranged in the second through hole, and an insulating heat conduction layer is arranged between the heat dissipation metal part and the heat dissipation area so as to insulate the conductive film from the heat dissipation metal part.

The method for manufacturing the printed circuit board comprises the steps that the printed circuit board is divided into a first printed circuit sub-board and a second printed circuit sub-board, a first through hole is formed in the first printed circuit sub-board, and a heat dissipation area is formed by a part, provided with a plurality of first through holes, of the first printed circuit sub-board; and arranging a conductive film on the inner wall of the first through hole, and filling a first heat-conducting medium in the first through hole. Arranging a second through hole on the second printed circuit daughter board, bonding and pressing the second printed circuit daughter board and the first printed circuit daughter board through the insulating bonding layer, wherein the second through hole corresponds to the heat dissipation area; and arranging a heat dissipation metal part in the second through hole, and arranging an insulating heat conduction layer at the bottom of the heat dissipation metal part so as to insulate the conductive film from the heat dissipation metal part. When installing electrical components, can directly install electrical components in the heat dissipation region of first printed circuit daughter board, electrical components accessible conductive film switches on with first printed circuit daughter board, is convenient for realize switching on of design circuit, and insulating heat-conducting layer makes conductive film and heat dissipation metalwork insulating simultaneously, can avoid printed circuit board signal unusual. Meanwhile, the electrical element is over against the first heat-conducting medium and sequentially passes through the first heat-conducting medium, the insulating heat-conducting layer and the heat-radiating metal part to radiate heat, the heat radiation of the electrical element can be directly radiated through the mounting position, and compared with a mode of radiating heat at the periphery of the electrical element in the related art, the heat-radiating piece directly corresponds to the electrical element, the heat-radiating effect is better, excessive heat-radiating pieces are not needed, the number of the heat-radiating pieces can be effectively reduced, and the technical effect of miniaturization of a printed circuit board is achieved.

According to the manufacturing method of the printed circuit board and the printed circuit board, when the electric element is installed, the electric element can be directly installed in the heat dissipation area of the first printed circuit sub-board, the electric element can be conducted with the first printed circuit sub-board through the conductive film, the conduction of a designed circuit is convenient to achieve, meanwhile, the conductive film is insulated from the heat dissipation metal piece through the insulating heat conduction layer, and the signal abnormity of the printed circuit board can be avoided. Meanwhile, the electrical element is over against the first heat-conducting medium and sequentially passes through the first heat-conducting medium, the insulating heat-conducting layer and the heat-radiating metal part to radiate heat, the heat radiation of the electrical element can be directly radiated through the mounting position, and compared with a mode of radiating heat at the periphery of the electrical element in the related art, the heat-radiating piece directly corresponds to the electrical element, the heat-radiating effect is better, excessive heat-radiating pieces are not needed, the number of the heat-radiating pieces can be effectively reduced, and the technical effect of miniaturization of a printed circuit board is achieved.

Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and other objects, features and advantages of the embodiments of the present invention will become more readily understood by the following detailed description with reference to the accompanying drawings. Embodiments of the invention will now be described, by way of example and not limitation, in the accompanying drawings, in which:

fig. 1 is a schematic cross-sectional view of an overall structure formed by a method for manufacturing a printed circuit board according to an embodiment of the present invention;

fig. 2 is an exploded view of a first printed circuit daughter board according to an embodiment of the present invention;

fig. 3 is a schematic cross-sectional view of a first printed circuit daughter board after being mixed and pressed according to an embodiment of the present invention;

fig. 4 is a schematic cross-sectional view of a first printed circuit daughter board provided with a conductive film and a first heat-conducting medium according to an embodiment of the present invention;

fig. 5 is a schematic cross-sectional view of a second printed circuit daughter board provided in accordance with an embodiment of the present invention before processing;

fig. 6 is a schematic cross-sectional view of a second printed circuit sub-board provided with a second through hole according to an embodiment of the present invention;

fig. 7 is a schematic cross-sectional view of a second printed circuit daughter board and a first printed circuit daughter board before being laminated according to an embodiment of the present invention;

fig. 8 is a schematic cross-sectional view of a second printed circuit daughter board and a first printed circuit daughter board after being laminated according to an embodiment of the present invention;

fig. 9 is a schematic cross-sectional view of fig. 8 with the preset removed.

Reference numerals:

11-a first printed circuit daughter board;

111-a conductive film; 112-a first heat-conducting medium;

113-a first printed circuit board;

1131 — a conductive layer; 1133 — a first insulating layer;

114-a third via;

115-high frequency printed circuit slicing;

1151-a second insulating layer;

116-a second printed circuit board; 117-prepreg;

13-a second printed circuit daughter board;

131-a second via; 132-a heat-dissipating metal piece;

133-insulating heat conducting layer; 134-a third insulating layer;

135-presets;

15-insulating adhesive layer.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

It should be understood that the following examples do not limit the order of execution of the steps of the claimed method. The various steps of the method of the invention can be performed in any possible order and in a round-robin fashion without contradicting each other.

In the description of the present invention, it is to be understood that the terms "thickness", "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; may be a mechanical connection; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the specification, reference to the description of "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Printed circuit boards are important electronic components in circuit connection, and the trend of development thereof is mainly around miniaturization. In the related art, the whole printed circuit board is made of high-frequency materials, the heat dissipation copper block penetrates through the printed circuit board along the thickness direction from the printed circuit board, and in the subsequent process of mounting electrical components, the electronic components can only be mounted by staggering the positions of the copper blocks. The copper block prevents the electronic element from being conducted with the printed circuit board through the copper block in the heat dissipation process, so that heat dissipation can be carried out only through the peripheral printed circuit board of the component. However, the heat dissipation copper block has poor heat dissipation effect by performing heat dissipation on the periphery, and more copper blocks need to be arranged in order to achieve the required heat dissipation effect, thereby further increasing the size of the printed circuit board.

In view of this, in the method for manufacturing a printed circuit board according to the embodiment of the present invention, the printed circuit board is divided into a first printed circuit sub-board and a second printed circuit sub-board, a first through hole is formed in the first printed circuit sub-board, and a portion of the first printed circuit sub-board having a plurality of first through holes forms a heat dissipation area; and arranging a conductive film on the inner wall of the first through hole, and filling a first heat-conducting medium in the first through hole. Arranging a second through hole on the second printed circuit daughter board, bonding and pressing the second printed circuit daughter board and the first printed circuit daughter board through the insulating bonding layer, wherein the second through hole corresponds to the heat dissipation area; and arranging a heat dissipation metal part in the second through hole, and arranging an insulating heat conduction layer at the bottom of the heat dissipation metal part so as to insulate the conductive film from the heat dissipation metal part. When installing electrical components, can directly install electrical components in the heat dissipation region of first printed circuit daughter board, electrical components accessible conductive film switches on with first printed circuit daughter board, is convenient for realize switching on of design circuit, and insulating heat-conducting layer makes conductive film and heat dissipation metalwork insulating simultaneously, can avoid printed circuit board signal unusual. Meanwhile, the electrical element is over against the first heat-conducting medium and sequentially passes through the first heat-conducting medium, the insulating heat-conducting layer and the heat-radiating metal part to radiate heat, the heat radiation of the electrical element can be directly radiated through the mounting position, and compared with a mode of radiating heat at the periphery of the electrical element in the related art, the heat-radiating piece directly corresponds to the electrical element, the heat-radiating effect is better, excessive heat-radiating pieces are not needed, the number of the heat-radiating pieces can be effectively reduced, and the technical effect of miniaturization of a printed circuit board is achieved.

Fig. 1 is a schematic cross-sectional view of an overall structure formed by a method for manufacturing a printed circuit board according to an embodiment of the present invention, and fig. 6 is a schematic cross-sectional view of a second printed circuit daughter board provided with a second through hole according to an embodiment of the present invention. Referring to fig. 1 and fig. 6, a method for manufacturing a printed circuit board according to an embodiment of the present invention includes: manufacturing a first printed circuit sub-board 11, forming a plurality of first through holes in the first printed circuit sub-board 11, wherein a heat dissipation area is formed in a part of the first printed circuit sub-board 11, which is provided with the plurality of first through holes: arranging a conductive film 111 on the inner wall of the first through hole, and filling a first heat-conducting medium 112; manufacturing a second printed circuit sub-board 13, and forming a second through hole 131 on the second printed circuit sub-board 13; bonding and pressing the second printed circuit daughter board 13 and the first printed circuit daughter board 11 through the insulating bonding layer 15, wherein the second through hole 131 corresponds to the heat dissipation area; a heat dissipation metal member 132 is disposed in the second through hole 131, and an insulating and heat conducting layer 133 is disposed at the bottom of the heat dissipation metal member 132 to insulate the conductive film 111 from the heat dissipation metal member 132.

Illustratively, the plurality of first through holes are arranged in a rectangular arrangement on the first printed circuit sub-board 11. The cross section of the heat dissipation area is rectangular as a whole. The second through-hole 131 is also rectangular in cross section. The cross section of the heat-dissipating metal member 132 may also be adaptively configured to be rectangular.

Specifically, the aperture of the first through hole may be 0.25mm to 0.5 mm.

For example, 100 first through holes may be disposed on the first printed circuit sub-board 11, and a square matrix of 10 rows and 10 columns is formed, and the distance between two adjacent first through holes is the same.

Illustratively, the second through hole 131 is a rectangular hole, and the cross-sectional area of the second through hole 131 is larger than that of the heat dissipation region. Specifically, the outer edge of the heat dissipation area formed by the first through hole may be 0.5mm to 1mm from the edge of the second through hole 131. It should be noted that, with such an arrangement, it can be ensured that all the heat transferred by the heat-conducting adhesive in the first through hole can be dissipated by the heat-dissipating metal member 132 disposed in the second through hole 131, so as to better ensure the heat dissipation effect.

Illustratively, the heat dissipating metal member 132 is a rectangular copper block.

Fig. 2 is an exploded schematic view of a manufacturing process of the first printed circuit sub-board according to the embodiment of the present invention, fig. 3 is a schematic cross-sectional view of the first printed circuit sub-board according to the embodiment of the present invention after being mixed and pressed, and fig. 4 is a schematic cross-sectional view of the first printed circuit sub-board according to the embodiment of the present invention after a conductive film and a first heat-conducting medium are disposed on the first printed circuit sub-board. Referring to fig. 2, 3 and 4, in an alternative exemplary embodiment, the step of manufacturing the first printed circuit sub-board 11 further includes: the first printed circuit daughter board 11 is formed by mixing and pressing a printed circuit board and a high-frequency printed circuit slice 115; a plurality of first through holes are formed in the high-frequency printed circuit slice 115 to form a heat dissipation area. It should be noted that the first printed circuit sub-board 11 is formed by mixing and pressing a printed circuit board and a high-frequency printed circuit board slice, and a plurality of first through holes are formed in the high-frequency printed circuit slice 115 region to form a heat dissipation region, that is, the high-frequency printed circuit slice 115 is arranged at a position where an electrical component needs to be mounted, and a common printed circuit board is used in other positions. Because the high-frequency material has high cost and is difficult to process, the high-frequency material is arranged at the part where the electrical element needs to be installed, so that the stable output of a high-frequency signal can be ensured; meanwhile, the problem that the whole plate is made of high-frequency materials so that the cost is high is avoided.

In an alternative exemplary embodiment, the first printed circuit sub-board 11 is formed by co-laminating a printed circuit board and the high-frequency printed circuit slice 115, and the specific steps include: a third through hole 114 having a predetermined shape is opened in the first printed circuit board 113; pressing the high-frequency printed circuit slice 115 matched with the shape of the third through hole 114 into the third through hole 114 to form a mixed-compression printed circuit board; and bonding the second printed circuit board 116 with the co-extruded printed circuit board through the prepreg 117 to obtain the molded first printed circuit daughter board 11.

Specifically, in the present embodiment, a third through hole 114 having a preset shape is formed in the first printed circuit board 113; pressing the high-frequency printed circuit slice 115 matched with the shape of the third through hole 114 into the third through hole 114 to form a mixed-compression printed circuit board, which can ensure the stable output of high-frequency signals; meanwhile, the high cost caused by the adoption of a high-frequency material in the whole plate is avoided. Subsequently, the second printed circuit board 116 is bonded with the mixed-compression printed circuit board through the prepreg 117 to obtain the molded first printed circuit daughter board 11, and the thickness of the first printed circuit daughter board 11 can be ensured by arranging the second printed circuit board 116, so that the space for internal wiring is increased, the surface area of the whole first printed circuit daughter board 11 is reduced, and the miniaturization of the whole molded printed circuit board is realized.

Specifically, in the process of bonding the second printed circuit sub-board 13 to the first printed circuit sub-board 11, the second printed circuit sub-board 13 is bonded to the side of the first printed circuit sub-board 11 away from the high-frequency printed circuit slice 115. In this configuration, when the electrical components are mounted in a later stage, the electrical components can be mounted on the side of the first printed circuit daughter board 11 close to the high-frequency printed circuit slice 115, thereby further ensuring stable output of the high-frequency signal.

Specifically, in the present embodiment, each of the first printed circuit board 113 and the second printed circuit board 116 includes conductive layers 1131 arranged in a stacked manner and a first insulating layer 1133 arranged between the adjacent conductive layers 1131; the high-frequency printed circuit slice 115 includes conductive layers 1131 stacked one on another and a second insulating layer 1151 provided between the adjacent conductive layers 1131, and the first printed circuit board 113 has the same thickness as the high-frequency printed circuit slice 115. The first insulating layer 1133 and the second insulating layer 1151 are two different insulating layers and are made of different insulating materials, wherein the second insulating layer 1151 is a material capable of ensuring stable output of a high-frequency signal. The thicknesses of the first printed circuit board 113 and the high-frequency printed circuit slice 115 are the same, so that the high-frequency printed circuit slice 115 can be pressed into the first printed circuit board 113 in a completely matched manner, and the stability of the whole structure is ensured.

Fig. 5 is a schematic cross-sectional view of a second printed circuit sub-board according to an embodiment of the present invention before processing, and referring to fig. 5, specifically, in this embodiment, the second printed circuit sub-board 13 includes conductive layers 1131 stacked on top of each other and a third insulating layer 134 disposed between the adjacent conductive layers 1131.

In an alternative exemplary embodiment, the sum of the number of layers of the conductive layer 1131 of the first printed circuit sub-board 11 and the conductive layer 1131 of the second printed circuit sub-board 13 is not less than six layers. It should be noted that, the sum of the number of the conductive layers 1131 of the first printed circuit sub-board 11 and the number of the conductive layers 1131 of the second printed circuit sub-board 13 is not less than six, so that the thickness of the whole printed circuit board formed by bonding the first printed circuit sub-board 11 and the second printed circuit sub-board 13 can be effectively ensured, and the space of internal wiring is further ensured to be increased, so that the surface area of the whole printed circuit board is reduced, and the miniaturization of the whole formed printed circuit board is realized.

Illustratively, in the present embodiment, the number of conductive layers 1131 of the first printed circuit sub-board 11 is four, and the number of conductive layers 1131 of the second printed circuit sub-board 116 is two. It is understood that the number of conductive layers 1131 of the first printed circuit sub-board 11 and the second printed circuit board 116 sub-board is not limited herein, and in other embodiments, the number of conductive layers 1131 of the first printed circuit sub-board 11 and the second printed circuit board 116 sub-board can be adaptively adjusted according to the specific requirements of the user. For example, the number of conductive layers 1131 of the first printed circuit sub-board 11 is four, five, or six, and the number of conductive layers 1131 of the second printed circuit sub-board 116 is three, four, or five.

Exemplarily, in the present embodiment, the second insulating layer 1151 is made of a high-frequency insulating material including: PPE resin, glass fiber cloth, aluminum oxide solid filler and organic solvent. The solid filler in the composition is not limited to one type of alumina solid, and may be adjusted to another type of solid filler according to the user's needs. It should be noted that, the specific composition of the high-frequency insulating material is not limited herein, and in other specific embodiments, the high-frequency insulating material may be adaptively adjusted according to the user's requirement, so that the high-frequency insulating material simultaneously ensures insulation and can ensure stable output of the high-frequency signal.

Illustratively, the first insulating layer 1133 and the third insulating layer 134 are made of the same material, and the first insulating layer 1133 includes: epoxy resin, glass fiber cloth and silica solid filler. The solid filler in the composition is not limited to silica, and may be suitably adjusted to another solid filler according to the user's needs. It should be noted that specific components of the material of the first insulating layer 1133 are not limited herein, and in other specific embodiments, the material can be adaptively adjusted according to the needs of a user.

Illustratively, the prepreg 117 includes an epoxy resin, a glass cloth, a silica solid filler, and an organic solvent. Epoxy resin, silicon dioxide solid filler and organic solvent are coated on two sides of the glass fiber cloth and heated to form a prepreg 117. After the prepreg 117 is subjected to high temperature and high pressure, the organic solvent disappears, and the main components thereof become epoxy resin, glass fiber cloth, and silica solid filler, that is, the same material as the first insulating layer 1133.

The conductive film 111 is provided on the inner wall of the first via hole, for example, by plating a copper film on the inner wall of the first via hole.

Exemplarily, the first through hole is filled with a first heat conducting medium 112, and the specific step is to fill a liquid heat conducting medium in the first through hole and solidify the liquid heat conducting medium to form the first heat conducting medium 112, where the first heat conducting medium 112 is a heat conducting insulating glue.

Illustratively, the insulating and heat conducting layer 133 is also a heat conducting insulating glue.

In this embodiment, the heat conductive insulating adhesive is a silica gel prepared by mixing organic silica gel as a main body, and polymer materials such as fillers and heat conductive materials. It has better heat conduction and electric insulation performance. The viscosity is 1200 +/-200 dpa.s, the heat conductivity coefficient is 0.8-3(W/m.K), and the heat conducting block can be solidified into a heat conducting block through baking at a high temperature of more than 125 ℃ for 2 +/-1H, thereby playing roles of heat dissipation and insulation in the printed circuit board.

Fig. 7 is a schematic cross-sectional view of the second printed circuit board and the first printed circuit board before being laminated according to the embodiment of the present invention, fig. 8 is a schematic cross-sectional view of the second printed circuit board and the first printed circuit board after being laminated according to the embodiment of the present invention, and fig. 9 is a schematic cross-sectional view of fig. 8 after the preset is taken out. Referring to fig. 7, 8 and 9, in an alternative exemplary embodiment, the second printed circuit sub-board 13 and the first printed circuit sub-board 11 are bonded and pressed by the insulating adhesive layer 15, and the specific steps include: placing a preset part 135 in the second through hole 131, wherein the shape of the preset part 135 is matched with that of the second through hole 131, the insulating adhesive layer 15 is arranged between the top surface of the first printed circuit daughter board 11 and the bottom surface of the second printed circuit daughter board 13 around the heat dissipation area, after the second printed circuit daughter board 13 is pressed with the first printed circuit daughter board 11, the top surface of the preset part 135 is flush with the top surface of the second printed circuit daughter board 13, and the bottom surface of the preset part 135 is abutted to the top surface of the heat dissipation area; wherein, the thickness of the preset member 135 is the sum of the depth of the second through hole 131 and the thickness of the insulating adhesive layer 15; the preset 135 is removed.

It should be noted that, by providing the preset component 135, the phenomenon that the insulating adhesive layer 15 disposed on the contact surface between the first printed circuit sub-board 11 and the second printed circuit sub-board 13 is lost and the adhesion is unstable due to the insulating adhesive layer 15 disposed on the contact surface between the first printed circuit sub-board 11 and the second printed circuit sub-board 13 being pressed into the second through hole 131 in the process of laminating the first printed circuit sub-board 11 and the second printed circuit sub-board 13 can be effectively avoided. Meanwhile, the situation that the heat dissipation metal piece 132 cannot be placed in the second through hole 131 due to the fact that the insulating adhesive layer 15 is pressed into the second through hole 131 is avoided.

It should be noted that the preset member 135 is configured to match the shape of the second through hole 131, so as to ensure the structural stability of the second printed circuit daughter board 13 during the pressing process.

It should be further noted that the insulating adhesive layer 15 is disposed between the top surface of the first printed circuit board 11 and the bottom surface of the second printed circuit board 13 around the heat dissipation area, after the second printed circuit board 13 is pressed on the first printed circuit board 11, the top surface of the preset member 135 is flush with the top surface of the second printed circuit board 13, and the bottom surface of the preset member 135 abuts against the top surface of the heat dissipation area. The insulating adhesive layer 15 can be prevented from being placed on the top surface of the heat dissipation area under the effect of the pressing force, and further the heat dissipation effect is prevented from being affected by the thickness of the heat dissipation metal part 132 arranged subsequently.

Illustratively, the insulating adhesive layer 15 is a low-flow prepreg 117, and the main components of the low-flow prepreg 117 are epoxy resin, glass fiber cloth and silica solid filler. It should be noted that the low-flow prepreg 117 changes solid into gel with the increase of temperature, and then changes gel into solid with the increase of temperature, thereby playing the role of insulation and adhesion. Wherein, the epoxy resin is the main body of the adhesive action, and the change of temperature causes the shape change of the glue. The glass fiber cloth is an insulating main body, and the change of temperature cannot cause the change of the shape of the glass fiber cloth. The higher the proportion of solid filler, the poorer the flowability of the low-flow prepreg 117.

Illustratively, the conductive layer 1131 includes a copper foil. It is understood that the specific material of the conductive layer 1131 is not limited herein, and in other specific embodiments, the conductive layer 1131 can be adapted to be other conductive substances according to the specific needs of the user.

In an alternative exemplary embodiment, a heat dissipation metal member 132 is disposed in the second through hole 131, and an insulating and heat conducting layer 133 is disposed at the bottom of the heat dissipation metal member 132 to insulate the conductive film 111 from the heat dissipation metal member 132, and the specific steps include: liquid heat-conducting medium is filled into the top surface of the heat dissipation area through the second through hole 131, the liquid heat-conducting medium becomes an insulating heat-conducting layer 133 after being solidified, and the thickness of the insulating heat-conducting layer 133 is the same as that of the insulating bonding layer 15; liquid metal is filled in the second through hole 131, the liquid metal is solidified to form a heat dissipation metal part 132, and the top surface of the heat dissipation metal part 132 is flush with the upper surface of the second printed circuit daughter board 13.

It should be noted that the liquid heat-conducting medium is filled in the top surface of the heat dissipation area through the second through hole 131, and the liquid heat-conducting medium becomes the insulating heat-conducting layer 133 after being cured, so that not only the heat dissipation effect can be ensured, but also the conductive film 111 and the heat dissipation metal member 132 can be prevented from being conducted, so that the signal is abnormal.

It should be noted that, the second through hole 131 is filled with liquid metal, the liquid metal is solidified to form the heat dissipation metal member 132, and after the first printed circuit sub-board 11 and the second printed circuit sub-board 13 are pressed together, one end of the second through hole 131 close to the first printed circuit sub-board is provided with the insulating and heat conducting layer 133, at this time, if the heat dissipation metal member 132 is directly installed, the installation is difficult due to the presence of gas in the second through hole 131. The second through hole 131 is filled with liquid metal, and the liquid metal is solidified to form the heat dissipation metal member 132, so that the technical problem can be effectively solved.

It should be further noted that the top surface of the heat dissipation metal member 132 is flush with the upper surface of the second printed circuit board 13, so as to ensure that the upper surface of the second printed circuit board 13 is flat and smooth, and ensure the stability of the structure.

Illustratively, the liquid metal is copper paste, the main component of which is copper powder, which serves as this heat sink therein, and the copper powder is spherical, flaky copper powder having an average particle size of the order of micrometers. The copper powder has the proportion of 78 +/-2 percent, the viscosity of 90 +/-20 dpa.s and the thermal conductivity of 300 to 400(W/m.K), and can be solidified into a copper block through baking at the high temperature of more than 125 ℃ for 2 +/-1H, thereby playing a role in heat dissipation in the second printed circuit sub-board 13.

With reference to fig. 1, the present invention further provides a printed circuit board, which is manufactured by the above manufacturing method of the printed circuit board, and includes a first printed circuit board 11 and a second printed circuit board 13, which are stacked, where the first printed circuit board 11 has a heat dissipation area, the first printed circuit board 11 in the heat dissipation area is provided with a plurality of first through holes, an inner wall of each first through hole is provided with a conductive film 111, and each first through hole is provided with a first heat conducting medium 112; a second through hole 131 is formed in the second printed circuit sub-board 13 at a position corresponding to the heat dissipation area, a heat dissipation metal member 132 is disposed in the second through hole 131, and an insulating and heat conducting layer 133 is disposed between the heat dissipation metal member 132 and the heat dissipation area, so that the conductive film 111 is insulated from the heat dissipation metal member 132.

When the printed circuit board provided by the invention is used for mounting electrical components, the electrical components can be directly mounted in the heat dissipation area of the first printed circuit sub-board 11, the electrical components can be conducted with the first printed circuit sub-board 11 through the conductive film 111, so that the conduction of a designed circuit is facilitated, meanwhile, the conductive film 111 is insulated from the heat dissipation metal part 132 through the insulating and heat conducting layer 133, and the signal abnormality of the printed circuit board can be avoided. Meanwhile, the electrical component faces the first heat-conducting medium 112 and radiates through the first heat-conducting medium 112, the insulating heat-conducting layer 133 and the heat-radiating metal part 132 in sequence, the heat radiation of the electrical component can be directly conducted through the installation position, and compared with a mode of radiating at the periphery of the electrical component in the related art, the heat radiating piece directly corresponds to the electrical component, the heat radiating effect is better, excessive heat radiating pieces are not needed, the number of the heat radiating pieces can be effectively reduced, and the technical effect of miniaturization of a printed circuit board is achieved.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. A method for manufacturing a printed circuit board, comprising:

manufacturing a first printed circuit sub-board, wherein a plurality of first through holes are formed in the first printed circuit sub-board, and a heat dissipation area is formed in a part, provided with the plurality of first through holes, of the first printed circuit sub-board:

arranging a conductive film on the inner wall of the first through hole, and filling a first heat-conducting medium;

manufacturing a second printed circuit sub-board, and forming a second through hole on the second printed circuit sub-board;

bonding and pressing the second printed circuit daughter board and the first printed circuit daughter board through an insulating bonding layer, wherein the second through hole corresponds to the heat dissipation area;

and arranging a heat dissipation metal part in the second through hole, and arranging an insulating heat conduction layer at the bottom of the heat dissipation metal part so as to insulate the conductive film from the heat dissipation metal part.

2. The method of claim 1, wherein the step of forming the first printed circuit sub-board further comprises: the first printed circuit daughter board is formed by mixing and pressing a printed circuit board and a high-frequency printed circuit slice;

and forming a plurality of first through holes in the high-frequency printed circuit slicing area to form a heat dissipation area.

3. The method for manufacturing a printed circuit board according to claim 2, wherein the first printed circuit daughter board is formed by mixing and pressing a printed circuit board and a high-frequency printed circuit slice, and the method comprises the following specific steps:

forming a third through hole with a preset shape in the first printed circuit board;

pressing the high-frequency printed circuit slice matched with the shape of the third through hole into the third through hole to form a mixed-compression printed circuit board;

and bonding a second printed circuit board with the mixed-compression printed circuit board through a prepreg to obtain the formed first printed circuit daughter board.

4. The method of manufacturing a printed circuit board according to claim 3, wherein each of the first printed circuit board and the second printed circuit board includes conductive layers disposed in a stacked manner and a first insulating layer disposed between the adjacent conductive layers;

the high-frequency printed circuit slice comprises conducting layers which are arranged in a stacked mode and a second insulating layer which is arranged between the adjacent conducting layers, and the thickness of the first printed circuit board is the same as that of the high-frequency printed circuit slice.

5. The method of claim 4, wherein said second printed circuit sub-board includes conductive layers disposed in a stacked arrangement and a third insulating layer disposed between adjacent said conductive layers.

6. The method of manufacturing a printed circuit board according to claim 5, wherein the sum of the number of the conductive layers of the first printed circuit sub-board and the second printed circuit sub-board is not less than six.

7. The method of manufacturing a printed circuit board according to claim 5, wherein the second insulating layer is made of a high-frequency insulating material comprising: PPE resin, glass fiber cloth, aluminum oxide solid filler and an organic solvent;

and/or the first insulating layer and the third insulating layer are made of the same material, and the first insulating layer comprises: epoxy resin, glass fiber cloth and silica solid filler;

and/or the conductive layer comprises copper foil.

8. The method for manufacturing a printed circuit board according to any one of claims 1 to 7, wherein the second printed circuit sub-board and the first printed circuit sub-board are bonded and pressed together by an insulating adhesive layer, and the method comprises the following specific steps:

placing a preset part in the second through hole, wherein the preset part is matched with the second through hole in shape, the insulating bonding layer surrounds the heat dissipation area and is arranged between the top surface of the first printed circuit daughter board and the bottom surface of the second printed circuit daughter board, after the second printed circuit daughter board is pressed with the first printed circuit daughter board, the top surface of the preset part is flush with the top surface of the second printed circuit daughter board, and the bottom surface of the preset part is abutted to the top surface of the heat dissipation area; the thickness of the preset part is the sum of the depth of the second through hole and the thickness of the insulating bonding layer;

and taking out the preset piece.

9. The method for manufacturing a printed circuit board according to any one of claims 1 to 7, wherein a heat dissipation metal member is disposed in the second through hole, and an insulating and heat conducting layer is disposed at a bottom of the heat dissipation metal member, so that the conductive film is insulated from the heat dissipation metal member, and the method comprises the following specific steps:

filling a liquid heat-conducting medium to the top surface of the heat dissipation area through the second through hole, wherein the liquid heat-conducting medium is the insulating heat-conducting layer after being solidified, and the thickness of the insulating heat-conducting layer is the same as that of the insulating bonding layer;

and filling liquid metal into the second through hole, wherein the liquid metal is solidified to form the heat dissipation metal part, and the top surface of the heat dissipation metal part is flush with the upper surface of the second printed circuit sub-board.

10. A printed circuit board manufactured by the method for manufacturing a printed circuit board according to any one of claims 1 to 9, wherein the printed circuit board includes a first printed circuit sub-board and a second printed circuit sub-board which are stacked, the first printed circuit sub-board has a heat dissipation area, a plurality of first through holes are formed in the first printed circuit sub-board in the heat dissipation area, an electrically conductive film is arranged on an inner wall of each first through hole, and a first heat-conducting medium is arranged in each first through hole;

and a second through hole is formed in the position, corresponding to the heat dissipation area, of the second printed circuit sub-board, a heat dissipation metal part is arranged in the second through hole, and an insulating heat conduction layer is arranged between the heat dissipation metal part and the heat dissipation area, so that the conductive film is insulated from the heat dissipation metal part.

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