CN116634700A

CN116634700A - Method for manufacturing circuit board with embedded metal block and circuit board with embedded metal block

Info

Publication number: CN116634700A
Application number: CN202310606301.8A
Authority: CN
Inventors: 赖灵; 唐海波; 杨云
Original assignee: Shengyi Electronics Co Ltd
Current assignee: Shengyi Electronics Co Ltd
Priority date: 2023-05-25
Filing date: 2023-05-25
Publication date: 2023-08-22

Abstract

The application discloses a preparation method of a circuit board with a buried metal block and the circuit board with the buried metal block, and belongs to the technical field of circuit boards. The preparation method of the circuit board with the embedded metal block comprises the following steps: the preparation method of the circuit board with the embedded metal block comprises the following steps: providing a multilayer board formed with mounting slots; the multi-layer board comprises a core board and prepregs, wherein an installation groove is formed in the core board, and one core board is a groove bottom core board; providing a metal block, wherein an anti-overflow glue groove is formed on the mounting end surface of the metal block; placing conductive adhesive into the overflow-preventing adhesive groove; placing the metal block into the mounting groove, and enabling the prepreg to be positioned between the mounting end face and the groove bottom core plate so as to form a plate to be pressed; and hot-pressing the board to be pressed. The glue overflow prevention groove can play a role in positioning, so that the placing position of the conductive glue is accurate. Meanwhile, in the hot pressing process, the conductive adhesive can flow into the overflow-preventing adhesive groove preferentially, so that the overflow-preventing adhesive groove can limit the flow of the conductive adhesive, and further, the overflow of the conductive adhesive is avoided.

Description

Method for manufacturing circuit board with embedded metal block and circuit board with embedded metal block

Technical Field

The application relates to the technical field of circuit boards, in particular to a preparation method of a circuit board with a buried metal block and the circuit board with the buried metal block.

Background

In the production process of the circuit board, the heat dissipation effect of the circuit board can be improved by embedding the copper block.

In the related art, the process of burying the copper block comprises the following steps: stacking a plurality of core boards and a plurality of prepregs to form a multi-layer board, forming a mounting groove on the multi-layer board, placing conductive adhesive at the upper end of the copper block, and inserting the copper block with the conductive adhesive into the mounting groove; then, a heat press treatment is performed to obtain a circuit board embedded with copper blocks.

It should be understood that during the hot pressing process, the conductive adhesive will flow earlier than the prepreg, and under the effect of pressure, the conductive adhesive will be thinned, the size in the horizontal direction becomes larger, the conductive adhesive diffuses in the direction of the upper end face of the copper block outwards, the conductive adhesive may flow onto different core boards, and the copper block is communicated with the surrounding area of the non-identical network, thereby causing a short circuit.

Disclosure of Invention

The present application aims to solve at least one of the technical problems existing in the prior art. Therefore, the application provides a preparation method of a circuit board with a buried metal block, which can prevent conductive adhesive from overflowing.

The application also provides the circuit board with the buried metal block, which is manufactured by the manufacturing method of the circuit board with the buried metal block.

The preparation method of the circuit board with the embedded metal block according to the embodiment of the first aspect of the application comprises the following steps:

providing a multilayer board formed with mounting slots; the multi-layer board comprises core boards and prepregs, wherein the core boards and the prepregs are stacked, at least one prepreg is arranged between any two adjacent core boards, one core board is a tank bottom core board, and the surface of the tank bottom core board forms the tank bottom of the mounting groove;

providing a metal block, wherein an anti-overflow glue groove is formed on the mounting end surface of the metal block;

placing conductive adhesive into the glue overflow preventing groove, wherein the thickness of the conductive adhesive is larger than the depth of the glue overflow preventing groove;

placing the metal block into the mounting groove, enabling the mounting end face to face the groove bottom core plate, and enabling at least one prepreg to be located between the mounting end face and the groove bottom core plate so as to form a plate to be pressed;

and hot-pressing the to-be-pressed plate, so that the heated conductive adhesive and the prepreg flow under the action of pressure, the prepreg positioned between the mounting end face and the tank bottom core plate fills the interval between the mounting end face and the tank bottom core plate, a sealing area is formed between the prepreg and the tank bottom core plate and between the prepreg and the metal block, and the conductive adhesive is filled in the sealing area.

The method for manufacturing the circuit board with the embedded metal block according to the embodiment of the first aspect of the application has at least the following beneficial effects: through forming anti-overflow glue groove at the upper end of metal piece, at the in-process that the conducting resin laminating was to the metal piece, anti-overflow glue groove can play a location's effect for the conducting resin puts the position accuracy. Meanwhile, in the hot pressing process, the conductive adhesive can flow into the overflow-preventing adhesive groove preferentially, so that the overflow-preventing adhesive groove can limit the flow of the conductive adhesive, and further, the overflow of the conductive adhesive is avoided, and the problem of short circuit of a circuit board caused by the overflow of the conductive adhesive is avoided. By placing the prepreg between the tank bottom core plate and the metal block, the prepreg will flow in the process of flowing the conductive adhesive, the prepreg can fill the space between the tank bottom core plate and the metal block to form a sealing area so as to limit the conductive adhesive in the sealing area, and the prepreg can flow towards the conductive adhesive and contact the conductive adhesive so as to limit the flow of the conductive adhesive.

According to some embodiments of the application, a groove is formed at the bottom of the glue overflow preventing groove;

the step of placing the conductive adhesive into the anti-overflow adhesive groove further comprises the following steps: and attaching the conductive adhesive to the bottom of the anti-overflow adhesive groove, so that at least one side edge of the conductive adhesive is placed in the groove or above the groove.

According to some embodiments of the application, the groove is an annular groove;

the step of placing the conductive adhesive into the anti-overflow adhesive groove further comprises the following steps: and pressing down the edge of the conductive adhesive to bend the edge of the conductive adhesive towards the annular groove, so that the edge of the conductive adhesive enters the annular groove.

According to some embodiments of the application, the annular groove is formed with a guiding surface for guiding an edge of the conductive paste to bend into the annular groove.

According to some embodiments of the application, the providing the metal block includes the steps of:

the glue overflow preventing groove is formed on the mounting end face in a machining mode;

processing the bottom of the glue overflow preventing groove to form the annular groove;

and a chamfer is formed on one end of the inner side wall of the annular groove, which is close to the mounting end surface, so as to form the guide surface.

According to some embodiments of the application, a distance from the mounting end face to the bottom of the groove is a, a distance from the mounting end face of the metal block to the bottom of the glue overflow preventing groove is b, a thickness of the conductive glue is c, and a thickness of the prepreg between the mounting end face and the core plate at the bottom of the groove is d; wherein d is less than or equal to c, b is less than or equal to 1/2c, and a is less than or equal to 2c.

According to some embodiments of the application, the providing a multiwall sheet comprises the steps of:

laminating a plurality of prepregs and a plurality of core boards to form a multi-layer board; wherein, one core plate is a tank bottom core plate, and a first prepreg and a second prepreg are sequentially attached to one side of the core plate;

a mounting groove extending to the surface of the groove bottom core plate is formed in one side of the multilayer plate, so that the surface of the groove bottom core plate forms the groove bottom of the mounting groove, the mounting groove forms a first accommodating hole on the first prepreg, and a second accommodating hole is formed on the second prepreg; the size of the first accommodating hole can block the metal block from passing through the first prepreg, and the size of the second accommodating hole can allow the metal block to pass through the second prepreg.

According to some embodiments of the application, the method further comprises the steps of:

and a power amplification groove is formed in the surface of one side of the notch of the multilayer plate, which is away from the mounting groove, wherein the groove bottom of the power amplification groove is positioned on the metal block.

According to some embodiments of the application, the hot pressing the board to be pressed further comprises the following steps:

and enabling the prepreg corresponding to the peripheral side surface of the metal block to flow under the action of pressure after being heated, and filling a gap between the peripheral side surface of the metal block and the groove wall of the mounting groove.

A circuit board of a buried metal block according to an embodiment of the second aspect of the present application includes: the circuit board of buried metal piece, multiply wood, metal piece and conductive adhesive.

The multi-layer board is formed by stacking a core board and prepregs and is provided with a mounting groove; at least one prepreg is arranged between any two adjacent core plates, one of the core plates is a tank bottom core plate, and the surface of the tank bottom core plate forms the tank bottom of the mounting tank;

the metal block is buried in the mounting groove, and an anti-overflow glue groove is formed on the mounting end surface of the metal block facing the groove bottom core plate, and the anti-overflow glue groove is used for accommodating conductive glue; at least one piece of prepreg fills the interval between the mounting end face and the tank bottom core plate, and forms a sealing area with the tank bottom core plate and the metal block;

and the conductive adhesive is filled in the sealing area.

The circuit board with the embedded metal block according to the embodiment of the second aspect of the application has at least the following beneficial effects: by arranging the glue overflow preventing groove on the metal block and matching the prepreg and the groove bottom core plate to form a sealing area, the conductive glue is limited in the sealing area, so that the problem of flowing overflow during the hot press forming of the conductive glue is avoided, and the quality of a finished product is better.

Additional aspects and advantages of the application 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 application.

Drawings

The application is further described with reference to the accompanying drawings and examples, in which:

fig. 1 is a step diagram of a method for manufacturing a circuit board with embedded metal blocks according to an embodiment of the first aspect of the present application;

FIG. 2 is a step diagram of providing the multiwall sheet of FIG. 1;

FIG. 3 is a step diagram of providing a metal block of FIG. 1;

FIG. 4 is a step diagram of placing the conductive paste in the paste overflow prevention groove in FIG. 1;

FIG. 5 is a schematic diagram of the structure of the metal block after the glue overflow preventing groove is formed;

FIG. 6 is a schematic view of the metal block of FIG. 5 after an annular groove is formed;

FIG. 7 is a top view of the metal block of FIG. 6;

FIG. 8 is a schematic view of the metal block of FIG. 6 after placement of conductive paste;

FIG. 9 is a schematic diagram of a structure of a board to be laminated;

FIG. 10 is a schematic view of the structure of the board to be pressed in FIG. 9 after hot pressing;

fig. 11 is a schematic diagram of a circuit board with an active amplifier slot embedded with a metal block.

Reference numerals:

the multi-layer board 100, the mounting groove 101, the core board 110, the groove bottom core board 110a, the prepreg 120, the first prepreg 121, the second prepreg 122 and the power amplifier groove 130;

the metal block 200, the mounting end face 201, the peripheral side face 202, the glue overflow prevention groove 210, the annular groove 211, the guide surface 2111 and the boss 212;

and a conductive adhesive 300.

Detailed Description

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the application.

In the description of the present application, it should be understood that references to orientation descriptions such as upper, lower, front, rear, left, right, etc. are based on the orientation or positional relationship shown in the drawings, are merely for convenience of description of the present application and to simplify the description, and do not indicate or imply that the apparatus or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present application.

In the description of the present application, the meaning of a number is one or more, the meaning of a number is two or more, and greater than, less than, exceeding, etc. are understood to exclude the present number, and the meaning of a number is understood to include the present number. The description of the first and second is for the purpose of distinguishing between technical features only and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present application, unless explicitly defined otherwise, terms such as arrangement, installation, connection, etc. should be construed broadly and the specific meaning of the terms in the present application can be reasonably determined by a person skilled in the art in combination with the specific contents of the technical scheme.

In the description of the present application, the descriptions of the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., mean 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 present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Referring to fig. 1, a method for manufacturing a circuit board with a buried metal block according to an embodiment of the first aspect of the present application includes the steps of:

s100, providing a multilayer board 100 formed with mounting grooves 101; referring to fig. 9, the multi-layer board 100 includes a core board 110 and prepregs 120, the core board 110 and the prepregs 120 are stacked, at least one prepreg 120 is disposed between any two adjacent core boards 110, and one of the core boards 110 is a groove bottom core board 110a, and the surface of the groove bottom core board 110a forms the groove bottom of the mounting groove 101.

It is understood that the process of forming the mounting groove 101 by the multi-layer board 100 may be to open the holes of the core board 110 and the prepreg 120, respectively, then stack the core board 110 and the prepreg 120, and connect the holes of the core board 110 and the holes of the prepreg 120 to each other, thereby forming the mounting groove 101 on the multi-layer board 100. Alternatively, after the core board 110 and the prepreg 120 are stacked, an opening process is performed on the stacked core board 110 and prepreg 120, thereby allowing the multi-layer board 100 to form the mounting groove 101. Specifically, in the present embodiment, the core plate 110 located at the uppermost side of the multilayer board 100 is a tank bottom core plate 110a. It should be understood that the surface of the core board 110 is attached with copper foil to form a circuit, and the conductive paste 300 can be attached to the core board 110 and conducted with the circuit on the surface of the core board 110.

S200, providing a metal block 200, and referring to FIG. 5, a glue overflow preventing groove 210 is formed on a mounting end surface 201 of the metal block 200;

it will be appreciated that the metal block 200 is cylindrical, such as a cylinder, prism, etc., whereby the metal block 200 has two end faces and a peripheral side face 202, one of which is the mounting end face 201. The material of the metal block 200 may be copper, copper alloy, aluminum or aluminum alloy.

S300, placing the conductive adhesive 300 into the glue overflow preventing groove 210, wherein the thickness of the conductive adhesive 300 is larger than the depth of the glue overflow preventing groove 210.

It can be appreciated that referring to fig. 8, the conductive adhesive 300 may be placed into the glue overflow preventing groove 210 by a person or a device, so that the conductive adhesive 300 is attached to the metal block 200, and the glue overflow preventing groove 210 has a certain positioning effect on the attaching process of the conductive adhesive 300, so as to avoid inaccurate placement position of the conductive adhesive 300. In addition, since the thickness of the conductive adhesive 300 is greater than the depth of the glue overflow preventing groove 210, one end of the conductive adhesive 300 far away from the glue overflow preventing groove 210 is exposed outside the glue overflow preventing groove 210, in this embodiment, the upper end of the conductive adhesive 300 is exposed outside the glue overflow preventing groove 210, so as to ensure that the conductive adhesive 300 can be adhered to the groove bottom core plate 110a.

S400, placing the metal block 200 into the mounting groove 101 with the mounting end surface 201 facing the groove bottom core plate 110a, and the at least one prepreg 120 located between the mounting end surface 201 and the groove bottom core plate 110a to form a board to be laminated.

It will be appreciated that referring to fig. 9, in the present embodiment, at least one prepreg 120 is mounted on the mounting end 201 and located between the mounting end 201 and the tank bottom core board 110a, and in other embodiments, the prepreg 120 may not be mounted on the metal block 200. And, since the upper end of the conductive paste 300 is exposed outside the glue overflow preventing groove 210, the prepreg 120 between the mounting end surface 201 and the groove bottom core plate 110a is disposed corresponding to the exposed upper end of the conductive paste 300, that is, the prepreg 120 is disposed around the circumference of the upper end of the conductive paste 300.

And S500, hot-pressing the to-be-pressed plate, so that the heated conductive adhesive 300 and the prepreg 120 flow under the action of pressure, the prepreg 120 positioned between the mounting end face 201 and the tank bottom core plate 110a fills the space between the mounting end face 201 and the tank bottom core plate 110a, a sealing area is formed between the prepreg and the tank bottom core plate 110a and the metal block 200, and the conductive adhesive 300 is filled in the sealing area.

It will be appreciated that referring to fig. 9 and 10, during the process of hot-pressing the board to be laminated, the conductive paste 300 flows, and the conductive paste 300 cannot flow out of the paste overflow preventing groove 210 in the horizontal direction due to the limit function of the paste overflow preventing groove 210, thereby avoiding the paste overflow of the conductive paste 300. Also, the prepreg 120 will flow during the hot pressing process, since at least one prepreg 120 is located between the mounting end face 201 and the tank bottom core board 110a, the prepreg 120 will fill the space between the tank bottom core board 110a and the mounting end face 201 to avoid the flowing conductive paste 300 from overflowing between the metal block 200 and the core board 110, and the prepreg 120 can cooperate with the tank bottom core board 110a and the metal block 200 to form a sealing area to restrict the conductive paste 300 within the sealing area. It is also understood that the prepreg 120 can flow in a horizontal direction, i.e., in a direction toward the conductive paste 300, such that the prepreg 120 contacts the conductive paste 300 to restrict the flow of the conductive paste 300. Thus, the prepreg 120 can further limit the flow and expansion of the conductive paste 300 in the horizontal direction during the flow of the conductive paste 300. It should be appreciated that the prepreg 120 can also flow into the glue overflow preventing groove 210 after flowing to ensure that the glue overflow preventing groove 210 is filled.

In summary, the application has at least the following advantages:

first, through forming anti-overflow glue groove 210 at terminal surface 201, in the laminating of conductive glue 300 to metal piece 200 in-process, anti-overflow glue groove 210 can play a location's effect for conductive glue 300 puts the position accuracy. Meanwhile, in the hot pressing process, the conductive adhesive 300 flows in the overflow preventing adhesive groove 210 preferentially, so that the overflow preventing adhesive groove 210 can limit the flow of the conductive adhesive 300, thereby avoiding the overflow of the conductive adhesive 300 and avoiding the problem of short circuit of the circuit board caused by the overflow of the conductive adhesive 300.

Secondly, by placing the prepreg 120 on the mounting end surface 201, the prepreg 120 will flow during the flowing process of the conductive adhesive 300, and the prepreg 120 can fill the space between the groove bottom core plate 110a and the mounting end surface 201 and form a sealing area with the groove bottom core plate 110a and the metal block 200, so that the conductive adhesive 300 is limited in the sealing area, and the prepreg 120 can flow towards the conductive adhesive 300 and contact with the conductive adhesive 300, so that the flowing of the conductive adhesive 300 is limited.

It should be noted that, the thickness of the conductive adhesive 300 is greater than the depth of the glue overflow preventing groove 210, when the volume of the conductive adhesive 300 is larger, that is, the length dimension and the width dimension of the conductive adhesive 300 are larger, the conductive adhesive 300 is closer to the inner wall surface of the glue overflow preventing groove 210, and after hot pressing, the conductive adhesive 300 may overflow from the glue overflow preventing groove 210; accordingly, when the volume of the conductive paste 300 is smaller, i.e., the length and width dimensions of the conductive paste 300 are smaller, the conductive paste 300 is farther from the inner wall surface of the flash preventing slot 210, there may be a case that the flash preventing slot 210 cannot be filled with the conductive paste 300 and the prepreg 120 after hot pressing, thereby causing a hole phenomenon.

To solve the above-described problem, referring to fig. 6, the groove bottom of the glue overflow preventing groove 210 is formed with a groove.

Thus, referring to fig. 4, S300, the step of placing the conductive paste 300 into the paste overflow prevention groove 210 further includes the steps of: and S310, attaching the conductive adhesive 300 to the bottom of the overflow-preventing adhesive groove 210, and placing at least one side edge of the conductive adhesive 300 into the groove or above the groove.

It can be appreciated that by adding a groove at the bottom of the glue overflow preventing groove 210, and placing the edge of the conductive glue 300 above the groove, after hot pressing, the flowing conductive glue 300 can flow into the groove first, and the flowing of the conductive glue 300 can be further limited by the groove, so that the glue overflow can be further avoided. Therefore, the conductive adhesive 300 with a relatively large volume can be used to avoid the hole phenomenon, and meanwhile, the situation of adhesive overflow can be avoided through the grooves. And, in the process of attaching the conductive adhesive 300, the edge of the conductive adhesive 300 can be placed corresponding to the groove, so that the attachment of the conductive adhesive 300 is more accurate.

Specifically, in the present embodiment, referring to fig. 6 and 7, the groove is an annular groove 211. Thus, referring to fig. 4, S300, the step of placing the conductive paste 300 into the paste overflow prevention groove 210 further includes the steps of: and S320, pressing down the edge of the conductive adhesive 300 to bend the edge of the conductive adhesive 300 towards the annular groove 211, so that the edge of the conductive adhesive 300 enters the annular groove 211.

It will be appreciated that referring to fig. 6, the groove is provided as the annular groove 211 such that the groove bottom of the glue overflow preventing groove 210 forms a boss 212 corresponding to the middle portion of the annular groove 211. In this embodiment, referring to fig. 8, the conductive paste 300 is rectangular and has four edges, the conductive paste 300 is placed on the boss 212, and the size of the conductive paste 300 is larger than that of the boss 212, and the edges of the conductive paste 300 protrude from the edges of the boss 212, so that the conductive paste 300 can be placed into the annular groove 211. Specifically, after the conductive paste 300 is placed in the paste overflow preventing groove 210, that is, on the boss 212, the edge of the conductive paste 300 is bent toward the inside of the annular groove 211 by gravity or a human force so that the edge of the conductive paste 300 can enter the annular groove 211.

It should be appreciated that by bending the edge of the conductive paste 300 into the annular groove 211, the annular groove 211 can play a role in positioning, and the fitting process of the conductive paste 300 can be more precise through the annular groove 211. And the annular groove 211 has the function of limiting the conductive adhesive 300, so that the conductive adhesive 300 is prevented from moving. And, when the conductive adhesive 300 flows, the conductive adhesive 300 flowing around in the horizontal direction can enter the annular groove 211, and the annular groove 211 can limit the conductive adhesive 300 to flow in any horizontal direction, so as to further improve the effect of limiting the conductive adhesive 300 to flow and further reduce the possibility of overflowing the conductive adhesive 300.

Specifically, in the present embodiment, referring to fig. 6 and 7, the annular groove 211 is formed at an edge portion of the groove bottom of the glue overflow preventing groove 210, that is, the groove wall of the glue overflow preventing groove 210 meets the outer groove wall of the annular groove 211.

In addition to the embodiment in which the grooves are provided as the annular grooves 211 as described above, in other embodiments, a corresponding number of grooves may be formed for only a part of the edges of the conductive paste 300.

In order to facilitate bending of the edge of the conductive paste 300 into the annular groove 211, in the present embodiment, referring to fig. 6, the annular groove 211 is formed with a guide surface 2111, and the guide surface 2111 is used to guide bending of the edge of the conductive paste 300 into the annular groove 211.

It is to be understood that the upper end of the inner side wall of the annular groove 211 forms a guide surface 2111, and the inner side wall of the annular groove 211, i.e., the inner wall of the inner ring of the annular groove 211; specifically, in the present embodiment, the guide surface 2111 is an arc surface, and in other embodiments, may be an inclined surface.

It should be appreciated that guide surface 2111 facilitates bending of conductive paste 300 into annular groove 211 and that conductive paste 300 can also be facilitated to flow into annular groove 211 by guide surface 2111 during the flow of conductive paste 300.

As can be seen from the above, referring to fig. 3, 5 and 6, S200, providing the metal block 200 includes the following steps:

s210, processing and forming an anti-overflow glue groove 210 on the mounting end face 201;

s220, machining an annular groove 211 at the bottom of the glue overflow preventing groove 210;

s230, a chamfer is formed on an end of the inner side wall of the annular groove 211 near the mounting end surface 201 to form a guide surface 2111.

Referring to fig. 6, the distance from the mounting end surface 201 to the bottom of the groove is a, the distance from the mounting end surface 201 to the bottom of the overflow preventing groove 210 is b, the thickness of the conductive adhesive 300 is c, and the thickness of the prepreg 120 between the mounting end surface 201 and the groove bottom core plate 110a is d. Wherein d is less than or equal to c, b is less than or equal to 1/2c, and a is less than or equal to 2c. To ensure that the grooves can be filled with the conductive paste 300 and the prepreg 120 after the hot pressing and the glue overflow preventing groove 210.

Whereby the ratio of a to b is set to 2 or more and 4 or less. Specifically, in this embodiment, the ratio of a to b is set to 3 to 1, i.e., a: ba 3:1. So as to ensure the glue overflow preventing effect of the groove and avoid the hole phenomenon.

As can be seen from the above, referring to fig. 2 and 9, S100, providing the multi-layer board 100 includes the following steps:

s110, laminating a plurality of prepregs 120 and a plurality of core plates 110 to form a multi-layer board; one of the core plates 110 is a bottom core plate 110a, and a first prepreg 121 and a second prepreg 122 are sequentially attached to one side of the bottom core plate.

It can be understood that two prepregs 120, namely a first prepreg 121 and a second prepreg 122, are disposed between the tank bottom core board 110a and the adjacent core board 110.

S120, a mounting groove 101 extending to the surface of the groove bottom core plate 110a is formed on one side of the multilayer board, so that the surface of the groove bottom core plate 110a forms the groove bottom of the mounting groove 101, the mounting groove 101 forms a first accommodating hole on the first prepreg 121, and forms a second accommodating hole on the second prepreg 122; wherein the first receiving hole is sized to block the metal block 200 from passing through the first prepreg 121 and the second receiving hole is sized to allow the metal block 200 to pass through the second prepreg 122.

It will be appreciated that the first receiving hole and the second receiving hole form part of the mounting groove 101. The size of the second receiving hole is larger than the outline size of the metal block 200 so that the metal block 200 can pass through the second receiving hole. The size of the first receiving hole is smaller than the outline size of the metal block 200 such that the metal block 200 cannot pass through the first receiving hole, and thus, the metal block 200 and the tank bottom core plate 110a sandwich the first prepreg 121, and the second prepreg 122 is disposed corresponding to the peripheral side 202 of the metal block 200.

Thus, after the metal block 200 is placed in the mounting groove 101, the first prepreg 121 is positioned between the mounting end face 201 and the groove bottom core plate 110a, the second prepreg 122 corresponds to the peripheral side face 202 of the metal block 200, and the conductive adhesive 300 is positioned in the first accommodation hole, and the metal block 200 is positioned in the second accommodation hole.

As can be appreciated, referring to fig. 9, since the upper end of the conductive paste 300 is exposed outside the glue overflow preventing groove 210, that is, the upper end of the conductive paste 300 protrudes from the mounting end surface 201, the upper end of the conductive paste 300 will be located in the first receiving hole, and the first prepreg 121 located between the mounting end surface 201 and the groove bottom core plate 110a corresponds to the exposed upper end of the conductive paste 300. Referring to fig. 10, after the hot pressing, the first prepreg 121 flows, can fill the space between the tank bottom core board 110a and the mounting end face 201, and serves to restrict the horizontal flow of the conductive paste 300.

It will be appreciated that, referring to fig. 9, the second prepreg 122 is located below the first prepreg 121 and is disposed corresponding to the peripheral side 202 of the metal block 200, and referring to fig. 10, after hot pressing, the second prepreg 122 flows toward the peripheral side 202 of the metal block 200 and is connected to the peripheral side 202 of the metal block 200, so that the further flow of the conductive paste 300 overflowing from the mounting end surface 201 is restricted, and the conductive paste 300 is prevented from flowing down the peripheral side 202 of the metal block 200.

In other embodiments, a stepped hole may be formed in one prepreg 120, so that an upper portion of the prepreg 120 is mounted on the mounting end face 201, and a lower portion of the prepreg 120 corresponds to a side face of the metal block 200.

The preparation method of the circuit board with the embedded metal block further comprises the following steps:

a power amplification groove 130 is formed in the surface of one side of the multilayer board 100, which faces away from the notch of the mounting groove 101, wherein the groove bottom of the power amplification groove 130 is positioned on the metal block 200.

It can be understood that referring to fig. 10 and 11, the power amplification groove 130 penetrates through the groove bottom core plate 110a, the conductive paste 300, and extends to the metal block 200 such that the groove bottom of the power amplification groove 130 is located on the metal block 200. The power amplifier slot 130 is used for placing chips, terminals, etc.

S500, hot pressing the board to be pressed, and further comprising the following steps:

so that the prepreg 120 corresponding to the circumferential side 202 of the metal block 200 flows under pressure after being heated and fills the gap between the circumferential side 202 of the metal block 200 and the sidewall of the installation groove 101.

It will be appreciated that after the metal block 200 is placed in the mounting groove 101, a gap is left between the peripheral side 202 of the metal block 200 and the side wall of the mounting groove 101, and after the board to be laminated is hot-pressed, the prepreg 120 will flow and fill into the gap.

Referring to fig. 11, a circuit board of a buried metal block according to an embodiment of the second aspect of the present application includes: a multilayer board 100, a metal block 200 and a conductive paste 300.

The multi-layer board 100 is formed by stacking a core board 110 and a prepreg 120, and is provided with a mounting groove 101; at least one prepreg 120 is arranged between any two adjacent core plates 110, one core plate 110 is a tank bottom core plate 110a, and the surface of the tank bottom core plate 110a forms the tank bottom of the mounting tank 101;

the metal block 200 is buried in the mounting groove 101, and a glue overflow preventing groove 210 is formed on a mounting end surface 201 of the metal block 200 facing the groove bottom core plate 110a, and the glue overflow preventing groove 210 is used for accommodating the conductive glue 300; at least one prepreg 120 fills the space between the mounting end face 201 and the tank bottom core plate 110a, and forms a sealing area with the tank bottom core plate 110a and the metal block 200;

the conductive paste 300 is filled in the sealing region.

It should be understood that the circuit board with embedded metal block according to the second aspect of the embodiment of the present application is manufactured by the manufacturing method of the circuit board with embedded metal block according to the first aspect of the embodiment.

The embodiments of the present application have been described in detail with reference to the accompanying drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of one of ordinary skill in the art without departing from the spirit of the present application. Furthermore, embodiments of the application and features of the embodiments may be combined with each other without conflict.

Claims

1. The preparation method of the circuit board with the embedded metal block is characterized by comprising the following steps:

2. The method for manufacturing a circuit board with embedded metal blocks according to claim 1, wherein grooves are formed at the bottoms of the glue overflow preventing grooves;

3. The method for manufacturing a circuit board embedded with a metal block according to claim 2, wherein the groove is an annular groove;

4. A method of manufacturing a circuit board embedded in a metal block as defined in claim 3, wherein the annular groove is formed with a guide surface for guiding an edge of the conductive paste to be bent toward inside of the annular groove.

5. The method of manufacturing a circuit board embedded with metal blocks as defined in claim 4, wherein said providing the metal blocks comprises the steps of:

6. The method for manufacturing a circuit board embedded with a metal block according to claim 3, wherein a distance from the mounting end face to the bottom of the groove is a, a distance from the mounting end face of the metal block to the bottom of the overflow preventing groove is b, a thickness of the conductive adhesive is c, and a thickness of the prepreg between the mounting end face and the core plate of the groove bottom is d; wherein d is less than or equal to c, b is less than or equal to 1/2c, and a is less than or equal to 2c.

7. The method of manufacturing a circuit board embedded with metal blocks according to claim 1, wherein said providing a multilayer board comprises the steps of:

8. The method of manufacturing a circuit board embedded with metal blocks according to claim 1, further comprising the steps of:

and one side of the multilayer plate, which is far away from the notch of the mounting groove, is provided with a power amplification groove, wherein the groove bottom of the power amplification groove is positioned on the metal block.

9. The method for manufacturing a circuit board with embedded metal blocks according to claim 1, wherein the hot pressing the board to be laminated further comprises the steps of:

10. The circuit board of buried metal piece, its characterized in that includes:

the multilayer board is formed by stacking a core board and prepregs and is provided with a mounting groove; at least one prepreg is arranged between any two adjacent core plates, one of the core plates is a tank bottom core plate, and the surface of the tank bottom core plate forms the tank bottom of the mounting tank;

the metal block is buried in the mounting groove, and an anti-overflow glue groove is formed on the mounting end face of the metal block facing the groove bottom core plate and is used for accommodating conductive glue; at least one piece of prepreg fills the interval between the mounting end face and the tank bottom core plate, and forms a sealing area with the tank bottom core plate and the metal block;

and the conductive adhesive is filled in the sealing area.