Chip-embedded printed circuit board and preparation method therefor

Abstract

Disclosed in the present invention are a chip-embedded printed circuit board and a preparation method therefor. The chip-embedded printed circuit board comprises a target circuit board, a chip unit, a plurality of connecting members, and a heat dissipation device. A mounting slot is formed on a first side of the target circuit board, and the chip unit is fixedly mounted in the corresponding mounting slot. The chip unit comprises a metal substrate and a chip; the chip is fixed and fitted onto a first side of the metal substrate, and is connected thererto. The connecting members are fixedly arranged on the first side of the target circuit board and are respectively connected to the chip or the target circuit board. The heat dissipation device is fitted onto a second side of the target circuit board, wherein the second side of the target circuit board is opposite the first side of the target circuit board. The heat dissipation device comprises a ceramic insulating plate and a heat sink. In this way, the present invention can improve the heat dissipation efficiency of the chip by means of the metal substrate, and enhance the insulation performance at the bottom of the entire chip-embedded printed circuit board.

Description

Chip embedded printed circuit board and manufacturing method thereof

TECHNICAL FIELD

[0001] The present application relates to the technical field of printed circuit boards, and particularly to a chip embedded printed circuit board and a manufacturing method thereof.

BACKGROUND

[0002] With the continuous promotion of global energy structure transformation, electric energy has become an increasingly important energy form; the power of various types of power devices is also increasing, and the heat dissipation demand of printed circuit boards (PCB) is also increasing.

[0003] The most widely used way to enhance the heat dissipation of PCBs at present is to embed copper base; however, the increase of copper base will affect the insulation protection effect of the printed circuit board.

SUMMARY

[0004] The present application provides a chip embedded printed circuit board and a manufacturing method thereof to simultaneously solve the problems of heat dissipation and insulation of the printed circuit board.

[0005] To solve the above technical problems, the present application provides a chip embedded printed circuit board, comprising: a target circuit board, at least one chip unit, a plurality of connecting pieces, and a heat dissipation device; at least one mounting groove is formed on the first side of the target circuit board, the chip unit is fixedly installed in the corresponding mounting groove, and the chip unit comprises at least one metal base plate and at least one chip; the chip is fixedly and adhesively arranged on the first side of the metal base plate and connected with the metal base plate; the connecting piece is fixedly arranged on the first side of the target circuit board and connected with the chip or the target circuit board respectively; the heat dissipation device is adhesively arranged on the second side of the target circuit board, and the second side of the target circuit board is the opposite side of the first side of the target circuit board; wherein the heat dissipation device comprises a ceramic insulation plate and a heat sink; the ceramic insulation plate is fixedly and adhesively arranged on the second side of the target circuit board, and the heat sink is fixedly and adhesively arranged on the side of the ceramic insulation plate away from the second side of the target circuit board.

[0006] The mounting groove is a through groove, and the second side of the metal base plate is adhesively arranged on the ceramic insulation plate through the mounting groove; the second side of the metal base plate is the opposite side of the first side of the metal base plate.

[0007] The ceramic insulation plate comprises a first metal layer, a ceramic insulation layer, and a second metal layer which are sequentially stacked and adhesively arranged, and a third metal layer is adhesively arranged on the second side of the target circuit board; the first metal layer and the third metal layer are fixedly and adhesively welded, and the second metal layer and the heat sink are fixedly and adhesively welded.

[0008] The ceramic insulating plate member includes a first metal layer and a ceramic insulating layer which are sequentially stacked and attached; the third metal layer is attached on the second side of the target circuit board; the heat sink is a metal heat sink; the first metal layer and the third metal layer are welded and fixed and attached; the metal heat sink and the ceramic insulating layer are welded and fixed and attached; the side of the metal heat sink away from the target circuit board extends outward to form a fluid spoiler structure.

[0009] The fourth peripheral edge of the third metal layer and the first metal layer of the heat dissipation device is recessed to form a hollow area, and the hollow area is filled with an insulating material; or the heat sink further includes a main plate which is attached and fixed on the side of the ceramic insulating plate member away from the target circuit board, wherein the peripheral edge of the main plate protrudes from the peripheral edge of the target circuit board, and the protruding part is vertically provided with an encapsulation shell which surrounds the peripheral edge of the ceramic insulating plate member and the target circuit board.

[0010] The ceramic insulating layer includes one or more of aluminum oxide, silicon nitride, aluminum nitride, beryllium oxide, and diamond; the thickness of the metal substrate ranges from 0.5 to 3.0 mm.

[0011] The first side of the metal substrate of each chip unit is formed with a groove, and the corresponding chip is mounted in the groove; or the first side of the metal substrate of each chip unit corresponds to the mounted chip, and the first side is further welded and fixed with a plurality of metal blocks which are spaced apart from the chip.

[0012] The chip-embedded printed circuit board further includes a first plastic encapsulation layer; the first plastic encapsulation layer encapsulates the first side of the target circuit board to fill the mounting grooves and encapsulate each chip unit; the connecting member includes a first connecting member, a second connecting member, and a third connecting member; one end of each connecting member is exposed outside the first plastic encapsulation layer, the other end of the first connecting member penetrates the first plastic encapsulation layer to connect with the chip, the other end of the second connecting member penetrates the first plastic encapsulation layer to connect with the first side of the metal substrate, and the other end of the third connecting member penetrates the first plastic encapsulation layer to connect with the first side of the target circuit board.

[0013] The chip unit further includes a second plastic encapsulation layer and an inner connecting member; the second plastic encapsulation layer encapsulates the first side of the metal substrate to fix the chip; one end of the inner connecting member is exposed outside the second plastic encapsulation layer, and the other end of the inner connecting member penetrates the second plastic encapsulation layer to connect with the chip or the metal substrate; the side of the second plastic encapsulation layer away from the metal substrate is encapsulated by the first plastic encapsulation layer; the first connecting member and the second connecting member are stacked with the inner connecting member and are connected with one end of the corresponding inner connecting member, respectively.

[0014] To solve the above technical problems, the application further provides a preparation method of a chip-embedded printed circuit board for preparing any of the chip-embedded printed circuit boards described above, comprising: obtaining a target circuit board, preparing at least one mounting groove at a preset position on a first side of the target circuit board; fixing and mounting a chip on a first side of a metal substrate, and fixing and mounting the metal substrate in the corresponding mounting groove; preparing a plurality of connecting pieces on the first side of the target circuit board to connect the chip or the target circuit board; attaching a heat dissipation device to a second side of the target circuit board to obtain a chip-embedded printed circuit board; wherein the heat dissipation device comprises a ceramic insulating plate and a heat sink.

[0015] Preparation of a plurality of connecting pieces on the first side of the target circuit board to connect the chip or the target circuit board comprises: covering a dry film on a part of the area on the side of the first plastic encapsulation layer away from the target circuit board, electroplating the side of the first plastic encapsulation layer away from the target circuit board until the blind hole is filled and an electroplated layer is formed on the side of the first plastic encapsulation layer away from the target circuit board, and removing the dry film to obtain the connecting piece; or electroplating the side of the first plastic encapsulation layer away from the target circuit board until the blind hole is filled and an electroplated layer is formed on the side of the first plastic encapsulation layer away from the target circuit board; and locally etching, laser ablation or mechanically removing the electroplated layer to obtain the connecting piece.

[0016] Preparation of a plurality of connecting pieces on the first side of the target circuit board to connect the chip or the target circuit board comprises: covering a dry film on a part of the area on the side of the first plastic encapsulation layer away from the target circuit board, electroplating the side of the first plastic encapsulation layer away from the target circuit board until the blind hole is filled and an electroplated layer is formed on the side of the first plastic encapsulation layer away from the target circuit board, and removing the dry film to obtain the connecting piece; or electroplating the side of the first plastic encapsulation layer away from the target circuit board until the blind hole is filled and an electroplated layer is formed on the side of the first plastic encapsulation layer away from the target circuit board; and locally etching, laser ablation or mechanically removing the electroplated layer to obtain the connecting piece.

[0017] The heat dissipation device comprises a ceramic insulating plate and a heat sink; the ceramic insulating plate is fixedly and adhesively arranged on the second side of the target circuit board, and the heat sink is fixedly and adhesively arranged on the side of the ceramic insulating plate away from the second side; the ceramic insulating plate comprises a first metal layer, a ceramic insulating layer and a second metal layer which are sequentially stacked and adhesively arranged, and the first metal layer is fixedly and adhesively arranged on the second side of the target circuit board.

[0018] To solve the above technical problems, the chip embedded printed circuit board of the present application sets the chip on the metal substrate to improve the heat dissipation efficiency of the chip through the metal substrate, and the metal substrate is built in the target circuit board, which can improve the layering of the above structure and improve the integration of the whole chip embedded printed circuit board. The second side of the target circuit board is also provided with a heat dissipation device, which can improve the heat dissipation efficiency of the chip heat by combining the metal substrate with the heat dissipation device, protect the working environment of the chip, and improve the working life of the chip. And the heat dissipation device includes a ceramic insulating plate, which can also insulate and protect the second side of the target circuit board, prevent the second side of the target circuit board from leaking to the radiator or the outside, and improve the safety and reliability of the chip embedded printed circuit board. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structural schematic diagram of the first embodiment of the chip embedded printed circuit board provided by the present application;

[0020] Figure 2 is a structural schematic diagram of another embodiment of the heat dissipation device provided by the present application;

[0021] Figure 3 is a structural schematic diagram of the second embodiment of the chip embedded printed circuit board provided by the present application;

[0022] Figure 4 is a structural schematic diagram of the third embodiment of the chip embedded printed circuit board provided by the present application;

[0023] Figure 5 is a structural schematic diagram of the second embodiment of the chip unit;

[0024] Figure 6 is a structural schematic diagram of the third embodiment of the chip unit;

[0025] Figure 7 is a structural schematic diagram of the fourth embodiment of the chip unit;

[0026] Figure 8 is a structural schematic diagram of the fourth embodiment of the chip embedded printed circuit board provided by the present application;

[0027] Figure 9 is a structural schematic diagram of the first embodiment of the preparation method of the chip embedded printed circuit board provided by the present application;

[0028] Figure 10 is a structural schematic diagram of the second embodiment of the preparation method of the chip embedded printed circuit board provided by the present application;

[0029] Figure 11 is a structural schematic diagram of the preparation process of the embodiment of Figure 10.

DETAILED DESCRIPTION

[0030] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be clearly and completely described below, obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0031] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications will also change accordingly.

[0032] In addition, if the embodiments of the present application involve descriptions such as "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of those skilled in the art, and when the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the scope of protection claimed by the present application.

[0033] Please refer to FIG. 1, which is a structural schematic diagram of a first embodiment of a chip embedded printed circuit board provided by the present application.

[0034] The chip embedded printed circuit board 100 of the present embodiment comprises a target circuit board 110, at least one chip unit 190, a plurality of connecting members 150, and a heat dissipation device 180. The chip unit 190 comprises at least one metal substrate 120 and at least one chip 130. The chip 130 is fixedly and adhesively arranged on the first side (not labeled in the figure) of the metal substrate 120 and is connected with the metal substrate 120.

[0035] The target circuit board 110 is a PCB (Printed Circuit Board) with prepared circuit structure, and the target circuit board 110 serves as the basic framework for embedding the chip 130; wherein the circuit of the target circuit board 110 is patterned. The target circuit board 110 can be a multi-layer board with only through-hole interconnection, or a HDI (High Density Interconnector) board containing blind-hole interconnection. The specific structure of the target circuit board 110 is set based on actual needs.

[0036] The first side 111 of the target circuit board 110 is provided with at least one mounting groove 113, and the chip unit 190 is fixedly installed in the corresponding mounting groove 113. One or more chip units 190 can be arranged on one target circuit board 110. The first side 111 of the target circuit board 110 is in the same side direction as the first side of the metal substrate 120.

[0037] The chip 130 can include a power chip, such as an IGBT (Insulate-Gate Bipolar Transistor) or a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), or other devices such as diodes, tubes, electromechanical elements, etc., which are not limited here.

[0038] The material of the metal substrate 120 can be copper, molybdenum copper, tungsten copper, etc., and its coefficient of thermal expansion (CTE) is 5-20 ppm / ℃, which matches the expansion coefficient of the chip 130, thereby maintaining structural stability between the chip 130 and the metal substrate 120, reducing stress caused by thermal expansion differences, and improving the connection stability between the chip 130 and the metal substrate 120.

[0039] The connecting piece 150 is used to lead out the signals of the chip 130 and the target circuit board 110, including but not limited to various metals and various metal structures. The connecting piece 150 is fixedly arranged on the first side 111 of the target circuit board 110 to connect with the chip 130 or the target circuit board 110, thereby leading out the signals of the chip 130 or the target circuit board 110.

[0040] In a specific application scenario, the mounting groove 113 can be a through groove, and the lower surface of the metal substrate 120 is coplanar with the lower surface of the target circuit board 110, so that the metal substrate 120 can reach the second side 112 of the target circuit board 110 and be directly connected with the heat dissipation device 180, thereby shortening the heat dissipation path and improving the efficiency of heat conduction from the chip 130 to the heat dissipation device 180 through the metal substrate 120, and improving the heat dissipation efficiency.

[0041] In a specific application scenario, the mounting groove 113 can be a blind groove, and the bottom of the blind groove is provided with insulating resin, and the insulating resin is inserted with a connecting structure to connect the bottom of the metal substrate 120 and the circuit pattern on the second side 112 of the target circuit board 110, thereby enabling the chip 130 to be sequentially conducted and dissipated through the metal substrate 120, the connecting structure, and the heat dissipation device 180.

[0042] The heat dissipation device 180 is arranged in abutment with the second side 112 of the target circuit board 110, and the second side 112 is opposite to the first side 111.

[0043] In some embodiments, the heat dissipation device 180 includes the ceramic insulation plate 160 and the heat sink 170; the ceramic insulation plate 160 is fixedly arranged in abutment with the second side 112 of the target circuit board 110, and the heat sink 170 is fixedly arranged in abutment with a side of the ceramic insulation plate 160 away from the second side 112.

[0044] The heat dissipation device 180 of the embodiment can be obtained by welding the ceramic insulation plate 160 on the heat sink 170, and the welding can include tin reflow soldering, silver sintering, etc. The heat sink 170 includes a metal heat sink, an air-cooled heat sink, or a liquid-cooled heat sink.

[0045] In a specific application scenario, the heat sink 170 can include a main plate 171 and a protruding heat dissipation structure 172; the main plate 171 is fixedly arranged in abutment with a side of the ceramic insulation plate 160 away from the second side 112, and the protruding heat dissipation structure 172 is fixedly arranged on a side of the main plate away from the ceramic insulation plate 160. The shape of the protruding heat dissipation structure 172 can include but is not limited to one or more of a column type, a corrugated type, a string piece, a fin, etc. The material of the heat sink 170 can include but is not limited to copper, aluminum, stainless steel, etc.

[0046] By fixedly arranging the ceramic insulation plate 160 in abutment with the second side 112 of the target circuit board 110, the second side 112 of the target circuit board 110 can be insulated and protected by the ceramic insulation plate 160, so as to prevent the second side 112 of the target circuit board 110 from being electrified to the heat sink 170 or the outside.

[0047] Through the above structure, the chip-embedded printed circuit board of the embodiment can improve the heat dissipation efficiency of the chip by arranging the chip on the metal substrate, and the metal substrate is built in the target circuit board, so as to improve the layering degree of the above structure and the integration of the entire chip-embedded printed circuit board. The second side of the target circuit board is further provided with a heat dissipation device, so as to improve the heat dissipation efficiency of the chip heat by combining the metal substrate and the heat dissipation device, protect the working environment of the chip, and improve the working life of the chip. In addition, the heat dissipation device includes a ceramic insulation plate, which can also insulate and protect the second side of the target circuit board, prevent the second side of the target circuit board from being electrified to the heat sink or the outside, and improve the safety and reliability of the chip-embedded printed circuit board.

[0048] In some embodiments, the mounting groove 113 is a through groove, and the second side 112 of the metal substrate 120 is arranged to be attached to the ceramic insulating plate 160 through the mounting groove 113. The second side (not labeled in the figure) of the metal substrate 120 is the opposite side of the first side of the metal substrate 120. The second side of the metal substrate 120 and the second side 112 of the target circuit board 110 are on the same side.

[0049] In some embodiments, the ceramic insulating plate 160 includes a first metal layer 161, a ceramic insulating layer 163, and a second metal layer 162 stacked and attached in sequence, and the first metal layer 161 is fixedly and attachedly arranged to the second side 112 of the target circuit board 110. The ceramic insulating plate 160 is a double-sided metal-clad ceramic substrate. The first metal layer 161 and the second metal layer 162 can be directly bonded or welded to the ceramic insulating layer 163 in between.

[0050] The thickness of the ceramic insulating layer 163 ranges from 0.05 mm to 1.00 mm, and can be 0.05 mm, 0.10 mm, 0.16 mm, 0.25 mm, 0.32 mm, 0.45 mm, 0.52 mm, 0.68 mm, 0.71 mm, 0.8 mm, 0.95 mm, or 1.00 mm, etc. Within this range, the ceramic insulating layer 163 can not only achieve insulation protection of the bottom of the target circuit board 110, but also avoid excessive thickness affecting the miniaturization and lightness of the chip-embedded printed circuit board 100.

[0051] The ceramic insulating plate 160 includes, but is not limited to, an active metal brazing (AMB) ceramic substrate, a direct copper clad (DBC) ceramic substrate, and a direct plating copper (DPC) ceramic substrate, wherein the ceramic insulating layer 163 can be one or more of alumina, silicon nitride, aluminum nitride, beryllium oxide, diamond, etc. The above-mentioned ceramic materials can not only achieve insulation protection, but also ensure the thermal conductivity of the ceramic insulating layer 163, which can reach 80 W / mK or even 1200 W / mK, far exceeding the thermal conductivity of materials such as silicone grease and resin, thereby greatly improving the heat dissipation efficiency. As a preferred solution, the thickness of the double-sided metal-clad ceramic substrate can be reduced as much as possible, and a ceramic material with high thermal conductivity is preferred; as a preferred solution, an AMB ceramic substrate with 0.25 mm silicon nitride ceramic can be selected.

[0052] The thickness of the first metal layer 161 and the second metal layer 162 ranges from 0.01 mm to 1.00 mm, and can be 0.05 mm, 0.11 mm, 0.17 mm, 0.25 mm, 0.3 mm, 0.45 mm, 0.52 mm, 0.63 mm, 0.75 mm, 0.8 mm, 0.95 mm, or 1.00 mm, etc. The thickness of the first metal layer 161 and the second metal layer 162 can be the same or different, and the material can include one or more of copper, aluminum, silver, titanium, tin, molybdenum, and tungsten.

[0053] In a specific application scenario, the third metal layer 114 can be attached on the second side 112 of the target circuit board 110 to be welded with the first metal layer 161, so as to fix the heat dissipation device 180. The second metal layer 162 is also arranged to be welded with the heat sink 170. The ceramic insulating plate 160 of the embodiment can be prepared in advance and then welded with the target circuit board 110, so as to independently realize high-temperature welding between the first metal layer 161 and the second metal layer 162 and the ceramic insulating layer 163, and avoid the influence of the high temperature on the reliability of the target circuit board 110. The third metal layer 114 can be a whole-plate metal or a conductive circuit, which is arranged based on actual needs.

[0054] In a specific application scenario, when the heat sink 170 is a metal heat sink, the protruding heat dissipation structure 172 can be arranged in one or more of the above-mentioned shapes to increase the heat dissipation area and improve the speed of heat dissipation to the air.

[0055] In a specific application scenario, when the heat sink 170 is an air-cooled heat sink, the side of the protruding heat dissipation structure 172 away from the target circuit board 110 can be arranged in one or more of the above-mentioned shapes, and a fan can be arranged to blow air to the side of the heat sink 170 away from the target circuit board 110, so as to further improve the speed of heat dissipation to the air.

[0056] In a specific application scenario, when the heat sink 170 is a liquid-cooled heat sink, the protruding heat dissipation structure 172 can be arranged in one or more of the above-mentioned shapes, and a base can be arranged on the side of the heat sink 170 away from the target circuit board 110 to form a containing cavity together with the main plate 171, and a water inlet and a water outlet can be arranged in the containing cavity, so as to pass cooling liquid into the containing cavity for liquid-cooled heat dissipation. The protruding heat dissipation structure 172 arranged in one or more of the above-mentioned shapes can form a fluid turbulence structure to increase the contact area between the heat sink 170 and the cooling liquid, thereby increasing the liquid-cooled heat dissipation speed.

[0057] Please refer to FIG. 2, which is a structural schematic diagram of another embodiment of the heat dissipation device provided by the application.

[0058] The heat dissipation device 280 of the embodiment includes a ceramic insulating plate 260 and a heat sink 270. A third metal layer is attached on the second side of the target circuit board, and the heat sink 270 is a metal heat sink.

[0059] The ceramic insulating plate 260 is fixed and attached to the second side of the target circuit board, and the ceramic insulating plate 260 comprises a first metal layer 261 and a ceramic insulating layer 263 which are sequentially stacked and attached, and the first metal layer 261 is fixed and attached to the third metal layer of the second side of the target circuit board. The heat sink 270 is fixed and attached to the side of the ceramic insulating plate 260 away from the second side.

[0060] The ceramic insulating plate 260 can still be a double-sided metal-clad ceramic substrate. The first metal layer 261 and the heat sink 270 can be directly bonded or welded to the ceramic insulating layer 263 in the middle.

[0061] The heat sink 270 of the present embodiment extends outwardly away from the side of the target circuit board to form a fluid spoiler structure. The fluid spoiler structure can include but is not limited to one or more of a column, a corrugated, a string piece, a fin, etc. The structure can be formed by etching or by mechanical depth control.

[0062] The heat dissipation structure of the present embodiment can realize both fixed welding with the target circuit board to ensure stable arrangement of the ceramic insulating layer 263, and stable arrangement between the heat sink 270 and the ceramic insulating layer 263.

[0063] The other structures of the present embodiment except the heat dissipation device 280 are the same as those of the foregoing embodiments, and will not be described again.

[0064] Please refer to FIG. 3, which is a structural schematic diagram of a second embodiment of a chip-embedded printed circuit board provided by the present application. The insulating method of the present embodiment is applied to any heat sink structure.

[0065] The third metal layer 314 of the target circuit board 310 and the first metal layer 361 of the heat dissipation device 380 of the present embodiment are inwardly recessed at the four peripheral edges to form hollowed-out areas, and the hollowed-out areas are filled with insulating material 381, i.e. the insulating material 381 is arranged around the connection between the target circuit board 310 and the heat dissipation device 380 to ensure that the insulating material 381 around the side surface of the connection is combined with the ceramic insulating layer 363 at the bottom to realize complete insulation of the bottom of the target circuit board 310, thereby improving the insulation reliability of the chip-embedded printed circuit board 300.

[0066] The welding and fixing between the third metal layer 314 and the first metal layer 361 can include but is not limited to tin reflow soldering, silver sintering, etc.

[0067] The insulating material 381 can be a solder resist material, an organic sealing material, or a mixed filling material composed of a solder resist material on the second side of the target circuit board 310 and a sealing material on the upper surface of the heat dissipation device 380.

[0068] The other structures of the chip-embedded printed circuit board 300 are the same as those of the foregoing embodiments, and please refer to the foregoing description.

[0069] Please refer to FIG. 4, which is a structural schematic diagram of a third embodiment of the chip-embedded printed circuit board provided by the present application.

[0070] The heat sink 480 further comprises a main plate 481, which is attached to and fixedly welded to the side of the ceramic insulation plate 460 that is away from the target circuit board 410. The ceramic insulation plate 460 can cover the edge of the main plate 481 or only cover part of the main plate 481.

[0071] The four edges of the main plate 481 protrude from the four edges of the target circuit board 410, and the protruding parts are vertically provided with the packaging shell 420, which surrounds the four edges of the ceramic insulation plate 460 and the target circuit board 410. The packaging shell 420, in combination with the ceramic insulation layer at the bottom, realizes complete insulation of the bottom of the target circuit board 410 and improves the reliability of the chip-embedded printed circuit board 400.

[0072] The packaging shell 420 can be filled with an insulating medium material to be fixed or be directly hollowed out. The packaging shell 420 can be an insulating resin or a metal material. The packaging shell 420 isolates the edge of the target circuit board 410 from the external environment.

[0073] The other structures of the chip-embedded printed circuit board 400 are the same as those of the foregoing embodiments, and please refer to the foregoing description.

[0074] In some embodiments, please refer back to FIG. 1, which is a structural schematic diagram of a first embodiment of a chip unit. The first side of the metal substrate 120 of each chip unit 190 is formed with a groove 121, and the corresponding chip 130 is installed in the groove 121.

[0075] The first side 111 of the target circuit board 110 is formed with at least one installation groove 113, and the metal substrate 120 is fixedly installed in the corresponding installation groove 113. The metal substrate 120 is formed with at least one groove 121 on the side close to the first side 111 of the target circuit board 110. The depth of the installation groove 113 is greater than the thickness of the metal substrate 120, so that the installation groove 113 completely accommodates the metal substrate 120. The chip 130 is fixedly installed in the corresponding groove 121 and connected with the metal substrate 120.

[0076] Correspondingly, at least one metal substrate 120, i.e. one or more metal substrates 120, is arranged in one mounting groove 113; and at least one chip 130, i.e. one or more chips 130, is arranged on one metal substrate 120. In this embodiment, one or more chips 130 can be arranged in the groove 121. The specific number of chips 130 and metal substrates 120 in the chip unit 190 is based on actual needs and is not limited herein. Specifically, one or more grooves 121 can be arranged on the metal substrate 120. The groove 121 corresponds to one chip 130 or one groove 121 corresponds to multiple chips 130. The specific arrangement is based on actual needs.

[0077] The direct contact between the metal substrate 120 and the chip 130 can improve the heat dissipation efficiency of the chip 130 by using the metal substrate 120. The built-in metal substrate 120 in the target circuit board 110 and the built-in chip 130 in the metal substrate 120 can improve the layering of the above structure and improve the integration of the entire chip-embedded printed circuit board 100. Since the chip 130 is installed in the groove 121 of the metal substrate 120, the metal substrate 120 can surround the bottom surface and the four surrounding sides of the chip 130, so that the chip 130 can dissipate heat to the metal substrate 120 through the bottom surface and the four surrounding sides, thereby improving the heat dissipation area and efficiency of the chip 130.

[0078] In some embodiments, the structure of the target circuit board 110 further includes a plurality of conductive circuit layers 101, a plurality of dielectric layers 102, and a plurality of vias 103. The plurality of conductive circuit layers 101 and the plurality of dielectric layers 102 are arranged in turn and alternately overlap and adhere. Each via 103 is arranged in the target circuit board 110 to connect at least two conductive circuit layers 101, respectively, so as to realize interlayer interconnection between all conductive circuit layers 101 by using the plurality of vias 103.

[0079] The dielectric layer 102 includes but is not limited to one or more of semi-cured sheets, epoxy resins, polyester resins (PET), polyimides, polyimide-based, polycarbonates (PC), bismaleimide triazine (BT)-based, Ajinomoto build film (ABF), FR4 resin, ceramic-based, and other insulating materials.

[0080] The specific arrangement of the conductive circuit layer 101, the dielectric layer 102, and the via 103 is based on the electrical function of the target circuit board 110 and is not limited herein.

[0081] In some embodiments, the chip-embedded printed circuit board 100 further comprises a first encapsulation layer 140, which comprises one or more of, but not limited to, epoxy resin, polyester resin (PET), polyimide, polyimide, polycarbonate (PC), bismaleimide triazine (BT), Ajinomoto build film (ABF), FR4 resin, ceramic-based insulating materials, etc.

[0082] The first encapsulation layer 140 encapsulates the first side 111 of the target circuit board 110 to fill the mounting grooves 113 and the grooves 121 and encapsulate and fix the metal substrates 120 and the chips 130.

[0083] The connectors 150 pass through the first encapsulation layer 140 on the first side 111 of the target circuit board 110, and the connectors 150 comprise first connectors 151, second connectors 152, and third connectors 153.

[0084] One end of each connector 150 is exposed outside the first encapsulation layer 140, wherein the other end of the first connector 151 passes through the first encapsulation layer 140 and is connected to the chip 130, the other end of the second connector 152 passes through the first encapsulation layer 140 and is connected to the first side of the metal substrate 120, and the other end of the third connector 153 passes through the first encapsulation layer 140 and is connected to the first side 111 of the target circuit board 110.

[0085] The first connector 151 and the second connector 152 respectively lead the top surface signals and the bottom surface signals of the chip 130 upward until they are exposed outside the first encapsulation layer 140. The second connector 152 connects the chip 130 by connecting the first side of the metal substrate 120. That is, this connection can lead the downward signals of the chip 130 upward through the metal substrate 120, which facilitates the connection of the second connector 152, so that all signals of the chip 130 can be led upward to reduce the space occupied by the signal leading of the chip 130 and further improve the integration of the chip-embedded printed circuit board 100.

[0086] The end of each connector 150 exposed outside the first encapsulation layer 140 can form a conductive circuit to meet the electrical function of the chip-embedded printed circuit board 100. The conductive circuit is connected to the pads on the upper surface of the chip 130, the metal substrate 120, and the inner layer conductive circuit of the target circuit board 110 through various connectors 150.

[0087] In some embodiments, the chip 130 is fixedly connected to the groove 121 by welding, which can be selected from tin reflow soldering, silver sintering, etc., and the silver sintering technology is preferred.

[0088] The single-pad side of the chip 130 is welded and fixed at the bottom of the corresponding groove 121 to be connected with the metal substrate 120; the double-pad side of the chip 130 is away from the bottom of the groove 121, and the double-pad side of the chip 130 includes a gate electrode, and either a source electrode (or a collector electrode) or a drain electrode (or an emitter electrode) of the chip 130 is arranged at the single-pad side, and the electrode of the single-pad side of the chip 130 is led out upward through the metal substrate 120 so that the other end of the second connecting member 152 is connected.

[0089] By arranging the double-pad side of the chip 130 away from the bottom of the groove 121, only the single-pad needs to be welded and connected with the groove 121, so that the difficulty of welding the chip 130 with the groove 121 is reduced, and the welding precision requirement is lowered.

[0090] The thickness of the metal substrate 120 ranges from 0.5 mm to 3.0 mm, preferably the thickness of the metal substrate 120 corresponding to the lower surface of the chip 130 ranges from 0.5 mm to 3.0 mm, and specifically can include 0.5 mm, 0.8 mm, 1.0 mm, 1.4 mm, 1.8 mm, 2.0 mm, 2.3 mm, 2.5 mm, 2.9 mm or 3.0 mm, etc. The metal substrate 120 in this thickness range can greatly improve the heat dissipation efficiency and shorten the heat dissipation path between the metal substrate 120 and the heat sink 170, further improving the heat dissipation efficiency.

[0091] Please refer to FIG. 5, which is a structural schematic diagram of a second embodiment of a chip unit.

[0092] In this embodiment, the chip unit 590 includes at least one metal substrate 520 and at least one chip 530.

[0093] The metal substrate 520 can include a metal plate 522 and a plurality of metal blocks 523, the plurality of metal blocks 523 are fixed on the first side of the metal substrate 520, and the plurality of metal blocks 523 are used to fill up the thickness of the chip 530 at the corresponding positions so as to connect the subsequent connecting members at the corresponding positions to realize the signal leading of the chip 530. The material of the metal plate 522 and the plurality of metal blocks 523 can be copper, molybdenum copper, tungsten copper, etc., and the coefficient of thermal expansion (CTE) thereof ranges from 5 ppm / ℃ to 20 ppm / ℃, preferably copper; the welding can be selected from tin reflow soldering, silver sintering, etc., preferably silver sintering technology.

[0094] Preferably, the thickness of the metal block 523 is not less than the thickness of the chip 530, so as to support and protect the chip 530 in the subsequent plastic packaging process, reduce the stress suffered by the chip 530 in the plastic packaging process, and improve the reliability and stability of the chip 530.

[0095] Please refer to FIG. 6, which is a structural schematic diagram of a third embodiment of a chip unit.

[0096] The chip unit 690 of the embodiment includes the second plastic sealing layer 640 and the inner layer connecting piece 650 on the basis of the metal substrate 620 and the chip 630.

[0097] The first side of the metal substrate 620 is plastic sealed by the second plastic sealing layer 640 to fix the chip 630. One end of the inner layer connecting piece 650 is exposed outside the second plastic sealing layer 640, and the other end of the inner layer connecting piece 650 passes through the second plastic sealing layer 640 and is connected with the chip 630 or the metal substrate 620 respectively.

[0098] One chip 630 needs three inner layer connecting pieces 650 to lead out three electrode signals respectively. One inner layer connecting piece 650 is connected with the bottom electrode of the chip 630 through the metal substrate 620 to realize the signal leading out.

[0099] The side of the second plastic sealing layer 640 away from the metal substrate 620 is plastic sealed by the first plastic sealing layer. The first connecting piece and the second connecting piece are stacked with the inner layer connecting piece 650 and are connected with one end of the corresponding inner layer connecting piece 650 respectively.

[0100] The structure of the metal substrate 620 of the embodiment can be the same as that of the metal substrate 120 in the embodiment of FIG. 1, but the structure of the second plastic sealing layer 640 and the inner layer connecting piece 650 is added.

[0101] The structure of the embodiment can first plastic seal the chip 630 through the second plastic sealing layer 640 and prepare the inner layer connecting piece 650 to lead out the signal, so as to pre-protect the chip 630 through the second plastic sealing layer 640, make the chip 630 have the stress protection of the second plastic sealing layer 640 in the plastic sealing process of the first plastic sealing layer, and improve the reliability and stability of the chip 630. The plastic sealing material of the second plastic sealing layer 640 can be higher than that of the first plastic sealing layer, so as to further improve the protection ability of the chip 630.

[0102] Please refer to FIG. 7, which is a structural schematic diagram of a fourth embodiment of a chip unit.

[0103] The chip unit 790 of the embodiment includes the second plastic sealing layer 740 and the inner layer connecting piece 750 on the basis of the metal substrate 720 and the chip 730. The positions and connections of the second plastic sealing layer 740 and the inner layer connecting piece 750 are similar to those of the second plastic sealing layer 640 and the inner layer connecting piece 650 in the foregoing embodiments, which will not be described herein.

[0104] The embodiment is applied to the case that the metal substrate 720 includes the metal plate 722 and the plurality of metal blocks 723, and the plurality of metal blocks 723 are welded and fixed on the first side of the metal substrate 720 through the welding layer 724.

[0105] The structure of the embodiment can first encapsulate the chip 730 through the second encapsulation layer 740, and prepare the inner layer connecting piece 750 to lead out the signals of the chip 730, so as to pre-protect the chip 730 through the second encapsulation layer 740, and make the chip 730 have the stress protection of the second encapsulation layer 740 in the encapsulation process of the first encapsulation layer, thereby improving the reliability and stability of the chip 730.

[0106] In the embodiments of FIGS. 5-7, the direct contact of the metal substrate with the chip can improve the heat dissipation efficiency of the chip by using the metal substrate. Embedding the metal substrate in the target circuit board and embedding the chip in the metal substrate can improve the layering of the above structure and improve the integration of the entire chip-embedded printed circuit board. Since the chip is mounted in the groove of the metal substrate, the metal substrate can surround the bottom surface and the four side surfaces of the chip, so that the chip can dissipate heat to the metal substrate through the bottom surface and the four side surfaces, thereby improving the heat dissipation area and efficiency of the chip.

[0107] Referring to FIG. 8, FIG. 8 is a structural schematic diagram of a fourth embodiment of a chip-embedded printed circuit board provided by the present application.

[0108] The structure of the chip unit 890 of the chip-embedded printed circuit board 800 of the embodiment is the structure of the chip unit 790 in the embodiment of FIG. 7. In other embodiments, the structure of the chip unit 890 can also be the structure of the chip unit 690 in the embodiment of FIG. 6 or the structure of the chip unit 590 in the embodiment of FIG. 5.

[0109] The structures of the target circuit board 810, the heat dissipation device 880, the connecting piece 850, and the first encapsulation layer 840 of the chip-embedded printed circuit board 800 of the embodiment are the same as those of the embodiment of FIG. 1, and will not be described again.

[0110] The metal substrate includes a metal plate and a plurality of metal blocks. The plurality of metal blocks and the chip are fixed on the first side of the metal substrate by a welding layer. The first side of the metal substrate is encapsulated by a second encapsulation layer. A plurality of inner layer connecting pieces are inserted into the second encapsulation layer to connect with the chip or the metal substrate, thereby leading out the signals of the chip.

[0111] The side of the second encapsulation layer away from the metal substrate is encapsulated by a first encapsulation layer. The first connecting piece and the second connecting piece are arranged in layers with the inner layer connecting piece and are connected with one end of the corresponding inner layer connecting piece, respectively.

[0112] With the above structure, the embedded chip printed circuit board of this embodiment improves the heat dissipation efficiency of the chip by mounting the chip within a metal substrate. Furthermore, the metal substrate being integrated into the target circuit board and the chip further integrated into the metal substrate increases the layering density and overall integration of the embedded chip printed circuit board. Some connectors connect to the chip via the first side of the metal substrate. This connection allows downward signals from the chip to be led upwards through the metal substrate, facilitating connector connections and enabling all chip signals to be led upwards, reducing the space occupied by signal output and further improving the integration of the embedded chip printed circuit board. The heat dissipation device, including a ceramic insulating plate, also provides insulation protection for the second side of the target circuit board, preventing leakage from the second side to the heat sink or external environment, thus improving the safety and reliability of the embedded chip printed circuit board. In this embodiment, the chip is first encapsulated using a second molding layer, and an inner layer connector is prepared to bring out its signals. This provides pre-protection of the chip through the second molding layer, ensuring stress protection during the molding process of the first molding layer and improving the chip's reliability and stability.

[0113] Please refer to Figure 9, which is a structural schematic diagram of the first embodiment of the chip-embedded printed circuit board fabrication method provided by the present invention. The chip-embedded printed circuit board fabrication method of this embodiment is used to fabricate chip-embedded printed circuit boards as described in any of the above embodiments.

[0114] Step S11: Obtain the target circuit board and prepare at least one mounting groove at a preset position on the first side of the target circuit board.

[0115] A target circuit board containing the circuit structure is fabricated as the basic framework for subsequent chip unit embedding. The circuits on the upper surface and inner layers of the target circuit board are patterned, while the lower surface has no conductive circuit pattern but may contain some structural patterns to assist in manufacturing or buffer structural stress. The target circuit board can be a multilayer board with only through-hole interconnects or an HDI board with blind via interconnects.

[0116] The target circuit board can have any number of layers, such as 5, 10, or 15, depending on the actual requirements.

[0117] The preset locations are where chips and metal substrates will be installed later. There can be one or more preset locations, depending on actual needs. No electrical structures are set at these preset locations on the target circuit board to allow for subsequent slotting. The mounting slots can be rectangular, square, or circular, etc., to match the shape of the subsequent chips and metal substrates.

[0118] Grooving can be done using methods such as mechanical depth control or laser cutting.

[0119] Step S12: Fixing and mounting the chip on the first side of the metal substrate, and fixing and mounting the metal substrate in the corresponding mounting groove.

[0120] Obtaining the metal substrate, fixing and mounting the chip on the first side of the metal substrate, and fixing and mounting the metal substrate in the corresponding mounting groove. The fixing and mounting mode can include welding, conductive glue bonding, etc.

[0121] The chip can include a power chip, such as an IGBT (Insulate-Gate Bipolar Transistor) or a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), or other devices such as diodes, tubes, electromechanical elements, etc., which are not limited here. The material of the metal substrate can be copper, molybdenum copper, tungsten copper, etc.

[0122] The mounting groove, the corresponding metal substrate, and the corresponding chip can constitute a chip unit of the chip-embedded printed circuit board, and one or more chip units can be provided on a target circuit board.

[0123] Direct contact between the metal substrate and the chip can improve the heat dissipation efficiency of the chip using the metal substrate. Embedding the metal substrate in the target circuit board can improve the layering of the above structure and improve the integration of the entire chip-embedded printed circuit board.

[0124] Step S13: Preparing a plurality of connecting pieces on the first side of the target circuit board to connect with the chip or the target circuit board.

[0125] The first side of the target circuit board and the first side of the metal substrate provided with the chip are on the same side. The connecting pieces are used to lead out the signals of the chip and the target circuit board, including but not limited to various metals and various metal structures.

[0126] The method of preparing a plurality of connecting pieces can include directly welding the connecting pieces on the surface of the chip and the target circuit board, or can form the connecting pieces by sequentially performing plastic sealing, drilling, and electroplating on the first side of the target circuit board. The connecting pieces are used to lead out the signals of the chip or the target circuit board.

[0127] Step S14: Attaching a heat dissipation device to the second side of the target circuit board to obtain a chip-embedded printed circuit board; wherein the heat dissipation device includes a ceramic insulating plate and a heat sink.

[0128] The second side of the target circuit board is opposite to the first side of the target circuit board. The heat dissipation device comprises a ceramic insulation plate and a heat sink; the ceramic insulation plate is fixedly and tightly arranged on the second side of the target circuit board, and the heat sink is fixedly and tightly arranged on the side of the ceramic insulation plate away from the second side.

[0129] The heat dissipation device of the embodiment can be obtained by welding the ceramic insulation plate on the heat sink, which can include tin reflow soldering, silver sintering, etc. The heat sink can include a metal heat sink, an air-cooled heat sink or a liquid-cooled heat sink. The shape of the protruding heat dissipation structure of the heat sink can include but is not limited to one or more of a column, a corrugated type, a string piece, a fin, etc. The material of the heat sink 170 can include but is not limited to copper, aluminum, stainless steel, etc.

[0130] By fixedly and tightly arranging the ceramic insulation plate on the second side of the target circuit board, the ceramic insulation plate can be used to insulate and protect the second side of the target circuit board, preventing the second side of the target circuit board from leaking to the heat sink or the outside world.

[0131] Through the above steps, the preparation method of the chip-embedded printed circuit board of the embodiment improves the heat dissipation efficiency of the chip through the metal substrate, and the metal substrate is built-in the target circuit board, which can improve the layering of the above structure and improve the integration of the entire chip-embedded printed circuit board. The second side of the target circuit board is also provided with a heat dissipation device, which can improve the heat dissipation efficiency of the chip heat by combining the metal substrate with the heat dissipation device, protect the working environment of the chip, and improve the working life of the chip. The heat dissipation device comprises a ceramic insulation plate, which can also insulate and protect the second side of the target circuit board, prevent the second side of the target circuit board from leaking to the heat sink or the outside world, and improve the safety and reliability of the chip-embedded printed circuit board.

[0132] Please refer to FIG. 10-FIG. 11, FIG. 10 is a structure schematic diagram of the second embodiment of the preparation method of the chip-embedded printed circuit board provided by the application. FIG. 11 is a structure schematic diagram of the preparation process of the embodiment of FIG. 10. The preparation method of the chip-embedded printed circuit board of the embodiment is used to prepare the chip-embedded printed circuit board of any of the above embodiments.

[0133] Step S21: obtaining a target circuit board, and preparing at least one mounting slot at a predetermined position of the target circuit board.

[0134] Referring to 9a in FIG. 11, a target circuit board 901 is obtained, which serves as a basic framework for embedding a chip; wherein the circuit of the target circuit board 901 is graphed. The target circuit board 901 can be a multi-layer board with only through-hole interconnections, or a HDI (High Density Interconnector) board containing blind-hole interconnections. The specific structure of the target circuit board 901 is set based on actual needs.

[0135] In a specific application scenario, the structure of the target circuit board 901 further includes a plurality of conductive circuit layers 903, a plurality of dielectric layers 904, and a plurality of vias 905. The conductive circuit layers 903 and the dielectric layers 904 are alternately and sequentially overlapped and attached, and each via 905 is arranged in the target circuit board 901 to connect at least two conductive circuit layers 903, so as to realize interlayer interconnection between all conductive circuit layers 905 by using the plurality of vias 905.

[0136] The preset position 902 of the target circuit board 901 is not provided with an electrical structure, so as to facilitate subsequent preparation of the mounting slot, but can contain some structural patterns for assisting manufacturing or buffering structural stress.

[0137] Referring to 9b in FIG. 11, at least one mounting slot 910 is prepared in the preset position 902 of the target circuit board 901. The number of the preset position 902 can be one or more. The preparation method of the mounting slot 910 can be mechanical cutting or laser ablation.

[0138] In the embodiment, the mounting slot 910 can be a through slot.

[0139] Step S22: fixing and mounting the chip in the corresponding groove of the metal substrate, and fixing and mounting the metal substrate in the corresponding mounting slot.

[0140] Referring to 9c in FIG. 11, in a specific application scenario, the mounting slot 910 includes a through slot. The mounting method of this step is: fixing and mounting the chip 930 in the corresponding groove 921 of the metal substrate 920 by welding, and integrally attaching a temporary carrier 911 to the second side 912 of the target circuit board 910; mounting the metal substrate 920 in the corresponding mounting slot 930 from the first side 913 of the target circuit board 901 until the metal substrate 920 contacts the temporary carrier 911.

[0141] The through slot can facilitate the attachment of the metal substrate 920 and the subsequent heat dissipation device, thereby shortening the heat dissipation path and improving the heat dissipation efficiency.

[0142] The temporary carrier 911 includes, but is not limited to, high-temperature adhesive tape, peelable film layer, peelable copper layer, and the like. The temporary carrier 911 is used to support the mounting of the metal substrate 920 in this step.

[0143] The depth of the recess 921 can be slightly greater than the thickness of the chip 930, so as to be completely accommodated and reduce stress collision in subsequent compression.

[0144] In this embodiment, the chip 930 and the metal substrate 920 are combined into a chip unit (not labeled), and in other embodiments, the chip unit can further include a second plastic encapsulation layer and an inner layer connector on the basis of the chip 930 and the metal substrate 920. For details, refer to FIGS. 6 and 7. For another embodiment of the structure of the metal substrate 920, refer to FIGS. 5 and 7, which will not be described again.

[0145] Step S23: Plastic encapsulation is performed on the first side of the target circuit board to fill the mounting slots and plastic encapsulate the metal substrates and the chips, so as to obtain a first plastic encapsulation layer.

[0146] Please further refer to 9d in FIG. 11. Plastic encapsulation is performed on the first side 913 of the target circuit board 901 to fill the mounting slots 910, fill the recesses 921, and plastic encapsulate the metal substrates 920 and the chips 930, so as to obtain a first plastic encapsulation layer 940.

[0147] The first plastic encapsulation layer 940 fills the mounting slots 910 of the target circuit board 901 and covers the side of the target circuit board 901 away from the temporary carrier 911. The filling method can be selected from plastic encapsulation technologies including compression molding, vacuum attachment scheme, and PCB lamination technology. The filling resin is preferably epoxy molding compound (EMC), and can also be Ajinomoto build film (ABF). When the PCB lamination technology is used to fill the resin, a thin copper foil with a thickness of 12 μm can be further coated on the surface of the resin during lamination. The thin copper foil facilitates the deposition of the subsequent electroplated layer.

[0148] After the plastic encapsulation, the temporary carrier 911 is removed.

[0149] In another specific application scenario, an organic insulating material (not shown in the figure) can also be laminated on the surface of the second side 912 of the target circuit board 901; the lamination method includes but is not limited to compression molding, vacuum attachment, PCB lamination technology; the organic insulating material includes but is not limited to one of FR4, BT, ABF or EMC. When using PCB lamination technology for plastic packaging, a thin copper foil with a thickness of 12 μm can also be coated on the surface of the resin during lamination; the thin copper foil facilitates the deposition of the subsequent electroplated layer. In this application scenario, the chip unit is actually installed in a blind groove due to the arrangement of the organic insulating material; and the lamination of the organic insulating material on the surface of the second side 912 of the target circuit board 901 is beneficial to realize stress balance between the surface plastic packaging layer 940 of the first side 913 of the target circuit board 901, and reduce the risk of product warping.

[0150] Step S24: Drilling the first plastic packaging layer to form a plurality of blind holes respectively exposing the chip, the first side of the metal substrate, and the first side of the target circuit board.

[0151] Please refer to 9e in FIG. 11, the side of the first plastic packaging layer 940 away from the target circuit board 901 is drilled to form a plurality of blind holes 950 respectively exposing the chip 930, the side of the metal substrate 920 close to the first side 913 of the target circuit board 901, and the first side 913 of the target circuit board 901.

[0152] That is, the plurality of blind holes 950 on the first plastic packaging layer 940, the side of the partially exposed chip 930, the side of the partially exposed metal substrate 920 close to the first side 913 of the target circuit board 901, and the remaining part of the first side 913 of the target circuit board 901 are exposed. In one specific application scenario, when the single-pad side of the chip 930 is welded and fixed on the metal substrate 920, and the double-pad side of the chip 930 is away from the metal substrate 920, the plurality of blind holes 950 corresponding to one chip unit have two exposed chips 930, one exposed metal substrate 920, and the remaining exposed first side 913 of the target circuit board 901.

[0153] The method for preparing the blind hole 950 is preferably laser processing, and the blind hole 950 is used to realize the pin pad of the chip 930 and the electrical signal lead-out of the target circuit board 901.

[0154] In another specific application scenario, the organic insulating material on the second side 912 of the target circuit board 901 can also be drilled at a position corresponding to a predetermined position to obtain a target blind hole exposing the metal substrate 920, so as to realize the thermal lead-out of the metal substrate 920 by electroplating the target blind hole in the subsequent process, thereby improving the heat dissipation effect of the metal substrate 920.

[0155] Step S25: electroplating the side of the first encapsulation layer away from the target circuit board to obtain the connecting pieces.

[0156] Please refer to 9f in FIG. 11, electroplating the side of the first encapsulation layer 940 away from the target circuit board 901 to obtain the connecting pieces 960.

[0157] The connecting pieces 960 include a first connecting piece 961, a second connecting piece 962, and a third connecting piece 963.

[0158] One end of each connecting piece 960 is exposed outside the first encapsulation layer 940, wherein the other end of the first connecting piece 961 is connected with the chip 930 through the first encapsulation layer 940, the other end of the second connecting piece 962 is connected with the side of the metal substrate 920 close to the first side 913 of the target circuit board 901 through the first encapsulation layer 940, and the other end of the third connecting piece 963 is connected with the first side 913 of the target circuit board 901 through the first encapsulation layer 940.

[0159] The first connecting piece 961 and the second connecting piece 962 respectively lead the top surface signals and the bottom surface signals of the chip 930 upward until exposed outside the first encapsulation layer 940.

[0160] The end of each connecting piece 960 exposed outside the first encapsulation layer 940 can form a conductive circuit to meet the electrical function of the chip embedded printed circuit board. The conductive circuit is connected with the pads on the upper surface of the chip 930, the metal substrate 920, and the inner layer conductive circuit of the target circuit board 901 through various connecting pieces 960.

[0161] In a specific application scenario, a dry film can be attached to part of the area on the side of the first encapsulation layer 940 away from the target circuit board 901, wherein the position of the dry film is determined based on the setting requirements of the layer conductive circuit. The side of the first encapsulation layer 940 away from the target circuit board 901 is electroplated until the blind hole 950 is filled and an electroplated layer is formed on the side of the first encapsulation layer 940 away from the target circuit board 901, the dry film is removed, and the connecting pieces 960 are obtained.

[0162] In a specific application scenario, the side of the first encapsulation layer 940 away from the target circuit board 901 can be electroplated until the blind hole 950 is filled and an electroplated layer is formed on the side of the first encapsulation layer 940 away from the target circuit board 901; the electroplated layer is locally etched, laser ablated, or mechanically removed to obtain the connecting pieces 960.

[0163] In this step, the blind hole 950 is filled by electroplating metal, and the circuit pattern is made; the circuit pattern can be made by semi-additive method, improved semi-additive method or subtractive method, and the subtractive method is preferred; before electroplating, a conductive seed layer is made on the opposite sides of the entire board by chemical copper plating or sputtering Ti / Cu; the side of the first plastic sealing layer 940 away from the target circuit board 901 contains a conductive circuit pattern, but the second side 912 of the target circuit board 901 does not contain a conductive circuit pattern, but a third metal layer 970 covering the entire lower surface, which can also contain necessary structure patterns for subsequent auxiliary assembly and stress buffering, etc. The third metal layer 970 is provided for subsequent welding of the heat dissipation device.

[0164] In another specific application scenario, the third metal layer 970 can be prepared by double-sided electroplating when electroplating the side of the first plastic sealing layer 940 away from the target circuit board 901.

[0165] In another specific application scenario, the third metal layer 970 can also be electroplated separately after the connecting piece 960 is obtained.

[0166] In another specific application scenario, when the second side 912 of the target circuit board 901 is laminated with organic insulating material, the target blind hole is processed on the organic insulating material; then the target blind hole is filled by electroplating, and the third metal layer 970 is formed; the connecting structure is formed in the target blind hole filled by electroplating, to connect the bottom of the metal substrate 920, and also to connect the circuit pattern on the second side 912 of the target circuit board 901, so that the chip 930 can be conducted to the heat dissipation device through the metal substrate 920 and the connecting structure in turn, further improving the heat dissipation efficiency.

[0167] After the circuit pattern is prepared, various components can be installed on the side of the first plastic sealing layer 940 away from the circuit pattern of the target circuit board 901 to meet the corresponding electrical requirements.

[0168] The entire board can also be subjected to necessary solder resist and surface treatment.

[0169] Step S26: mounting a heat dissipation device on the second side of the target circuit board to form a chip-embedded printed circuit board.

[0170] Please refer to 9g in FIG. 11, mounting a heat dissipation device 980 on the second side 912 of the target circuit board 901 to form a chip-embedded printed circuit board 900.

[0171] The heat dissipation device 980 comprises a ceramic insulating plate 981 and a heat sink 982. The ceramic insulating plate 981 is fixedly and tightly arranged on the second side 912 of the target circuit board 901, and the heat sink 982 is fixedly and tightly arranged on the side of the ceramic insulating plate 981 away from the second side 912. The ceramic insulating plate 981 comprises a first metal layer 983, a ceramic insulating layer 984 and a second metal layer 985 which are sequentially and tightly arranged. The first metal layer 983 is fixedly and tightly arranged on the second side 912 of the target circuit board 901. The heat sink 982 comprises but is not limited to a metal heat sink, an air-cooled heat sink or a liquid-cooled heat sink.

[0172] The size of the heat sink 982 can be smaller than, equal to or larger than the size of the embedded chip unit.

[0173] The preparation method of the chip-embedded printed circuit board of the embodiment is to mount a chip in a groove of a metal substrate to obtain a chip unit, and further embed the module into a target circuit board. The lower surface of the metal substrate of the chip unit is coplanar with the lower surface of the target circuit board, and the metal substrate of the chip unit is directly connected with the heat sink. There is an insulating ceramic layer in the heat sink, which separates the heat sink into electrically insulated upper and lower parts. The upper part is directly connected with the bottom of the chip module and the lower surface of the target circuit board, and the lower part contains a fluid turbulence structure. In this structure, the heat of the chip is first transmitted to the metal substrate, and then directly transmitted to the heat sink. The heat sink can realize the electrical insulation between the power chip and the metal substrate and the outside through the intermediate high-thermal-conductivity and high-insulation ceramic insulating layer, thereby maximizing the heat dissipation of the chip. The embodiment also integrates the chip at high density on the target circuit board to improve the system integration, and uses a connecting piece formed by a blind hole copper to realize the electrode lead-out of the chip, which can reduce the parasitic inductance of the package.

[0174] The above is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent flow transformation based on the content of the specification and drawings, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the present application.

Claims

1. A chip-in-pcb, wherein, The chip-embedded printed circuit board comprises: a target circuit board, at least one mounting slot being formed on a first side of the target circuit board; at least one chip unit, the chip unit being fixedly installed in a corresponding mounting slot, the chip unit comprising at least one metal substrate and at least one chip, the chip being fixedly and adhesively arranged on a first side of the metal substrate and connected with the metal substrate; a plurality of connecting members, the connecting members being fixedly arranged on the first side of the target circuit board and connected with the chip or the target circuit board respectively; a heat dissipation device, the heat dissipation device being adhesively arranged on a second side of the target circuit board, the second side of the target circuit board being opposite to the first side of the target circuit board, wherein the heat dissipation device comprises a ceramic insulating plate and a heat sink, the ceramic insulating plate being fixedly and adhesively arranged on the second side of the target circuit board, and the heat sink being fixedly and adhesively arranged on a side of the ceramic insulating plate away from the second side of the target circuit board.

2. The chip-embedded printed circuit board according to claim 1, wherein the mounting slot is a through slot, a second side of the metal substrate being adhesively arranged on the ceramic insulating plate through the mounting slot, the second side of the metal substrate being opposite to the first side of the metal substrate.

3. The chip-embedded printed circuit board according to claim 1, wherein the ceramic insulating plate comprises a first metal layer, a ceramic insulating layer and a second metal layer which are sequentially laminated and adhesively arranged, and a third metal layer is adhesively arranged on the second side of the target circuit board; the first metal layer and the third metal layer are fixedly and adhesively welded, and the second metal layer and the heat sink are fixedly and adhesively welded.

4. The chip-in-pcb of claim 1, wherein, the ceramic insulating plate comprises a first metal layer and a ceramic insulating layer which are sequentially laminated and adhesively arranged, and a third metal layer is adhesively arranged on the second side of the target circuit board, and the heat sink is a metal heat sink; the first metal layer and the third metal layer are fixedly and adhesively welded, and the metal heat sink and the ceramic insulating layer are fixedly and adhesively welded; wherein the metal heat sink extends outwardly from a side thereof away from the target circuit board to form a fluid turbulence structure.

5. The chip-embedded printed circuit board according to claim 3 or 4, wherein the third metal layer and the first metal layer of the heat dissipation device are recessed inwardly at their periphery to form a hollow region, and the hollow region is filled with an insulating material; or the heat sink further comprises a main plate, the main plate being adhesively and fixedly arranged on a side of the ceramic insulating plate away from the target circuit board, wherein the periphery of the main plate protrudes from the periphery of the target circuit board, and an encapsulation shell is vertically arranged on the protruding part, the encapsulation shell surrounding the periphery of the ceramic insulating plate and the target circuit board.

6. The chip-in-pcb of claim 3 or 4, wherein, the ceramic insulating layer comprises one or more of aluminum oxide, silicon nitride, aluminum nitride, beryllium oxide and diamond; the thickness of the metal substrate ranges from 0.5 to 3.0 mm.

7. The chip-in-pcb of claim 4, wherein, the thickness of the ceramic insulating layer ranges from 0.05 to 1.00 mm.

8. The chip-in-pcb of claim 4, wherein, The first metal layer and the second metal layer have a thickness ranging from 0.01 mm to 1.00 mm.

9. The chip-in-pcb of claim 4, wherein, The fluid disturbance structure has a shape including one or more of a column, a corrugated shape, a string piece, a fin, and the like.

10. The chip-in-pcb of claim 1, wherein, The heat sink includes an air-cooled heat sink, a liquid-cooled heat sink, or a liquid-cooled heat sink. The liquid-cooled heat sink is provided with a base on a side away from the target circuit board, and a containing cavity is formed by the base and the main plate. An inlet and an outlet are provided in the containing cavity to introduce cooling liquid into the containing cavity for liquid cooling.

11. The chip-embedded printed circuit board of claim 1, wherein, The first side of the metal substrate of each chip unit is formed with a groove, and the corresponding chip is mounted in the groove; or The first side of the metal substrate of each chip unit corresponds to the mounting of the chip, and the first side is also welded and fixed with a plurality of metal blocks, which are arranged at intervals with the chip.

12. The chip-in-pcb of claim 11, wherein, The chip-embedded printed circuit board further comprises a first plastic encapsulation layer; The first plastic encapsulation layer encapsulates the first side of the target circuit board to fill the mounting grooves and encapsulate each chip unit; The connecting member includes a first connecting member, a second connecting member, and a third connecting member; One end of each connecting member is exposed outside the first plastic encapsulation layer, the other end of the first connecting member penetrates the first plastic encapsulation layer and connects with the chip, the other end of the second connecting member penetrates the first plastic encapsulation layer and connects with the first side of the metal substrate, and the other end of the third connecting member penetrates the first plastic encapsulation layer and connects with the first side of the target circuit board.

13. The chip-in-pcb of claim 12, wherein, The first plastic encapsulation layer includes one or more of epoxy resin, polyester resin, polyimide, polyimide, polycarbonate, bismaleimide triazine, Ajinomoto laminated adhesive film, FR4 resin, and ceramic-based material.

14. The chip-in-pcb of claim 12, wherein, The chip unit further comprises a second plastic encapsulation layer and an inner layer connecting member; The second plastic encapsulation layer encapsulates the first side of the metal substrate to fix the chip; one end of the inner layer connecting member is exposed outside the second plastic encapsulation layer, and the other end of the inner layer connecting member penetrates the second plastic encapsulation layer and connects with the chip or metal substrate, respectively; The side of the second plastic encapsulation layer away from the metal substrate is encapsulated by the first plastic encapsulation layer; The first connecting member and the second connecting member are stacked with the inner layer connecting member and connected with one end of the corresponding inner layer connecting member, respectively.

15. A method of manufacturing a chip-in-pcb, wherein, The preparation method of the chip-embedded printed circuit board is used to prepare the chip-embedded printed circuit board as claimed in any one of claims 1-14, comprising: Obtaining a target circuit board, and preparing at least one mounting groove at a predetermined position on the first side of the target circuit board; Fixing and mounting a chip on the first side of a metal substrate, and fixing and mounting the metal substrate in the corresponding mounting groove; Preparing a plurality of connecting members on the first side of the target circuit board to connect with the chip or the target circuit board; Attaching a heat dissipation device to the second side of the target circuit board to obtain the chip-embedded printed circuit board; wherein the heat dissipation device includes a ceramic insulating plate and a heat sink.

16. The method for fabricating a chip-embedded printed circuit board according to claim 15, wherein, The method comprises the following steps: Preparation of a plurality of connectors on the first side of the target circuit board to connect with the chip or the target circuit board, comprising: Plastic encapsulation of the first side of the target circuit board to fill the mounting slots and plastic encapsulate the metal substrates and the chips, obtaining a first plastic encapsulation layer; Drilling of the first plastic encapsulation layer to form a plurality of blind holes respectively exposing the first side of the target circuit board, the first side of the metal substrates and the chips; 17. The method for fabricating a chip-embedded printed circuit board according to claim 16, wherein, Electroplating of the side of the first plastic encapsulation layer away from the target circuit board to obtain the connectors. The electroplating of the side of the first plastic encapsulation layer away from the target circuit board to obtain the connectors, comprising: Pasting of dry film on part of the area of the side of the first plastic encapsulation layer away from the target circuit board; Electroplating of the side of the first plastic encapsulation layer away from the target circuit board until the blind holes are filled and an electroplated layer is formed on the side of the first plastic encapsulation layer away from the target circuit board; 18. The method for fabricating a chip-embedded printed circuit board according to claim 16, wherein, Removal of the dry film to obtain the connectors. The electroplating of the side of the first plastic encapsulation layer away from the target circuit board to obtain the connectors, comprising: Electroplating of the side of the first plastic encapsulation layer away from the target circuit board until the blind holes are filled and an electroplated layer is formed on the side of the first plastic encapsulation layer away from the target circuit board; Local etching, laser ablation or mechanical removal of the electroplated layer to obtain the connectors.

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