TWI599290B - Printed circuit board with embeded electronic component and method for manufacturing same - Google Patents

Description

Circuit board with embedded components and manufacturing method thereof

The present invention relates to the field of circuit board manufacturing, and in particular to a circuit board having embedded components and a method of fabricating the same.

In order to achieve the purpose of lightness and thinness, manufacturers have begun to change the electronic components originally soldered on the surface of the multilayer circuit board into the inside of the multilayer circuit board, thereby increasing the wiring area on the surface of the circuit board and reducing the size of the circuit board. And reducing its weight and thickness, the electronic component can be an active or passive component. When the embedded multilayer electronic circuit board is embedded in the embedded electronic component, the solder paste electronic component needs to be soldered into the circuit board by over-reflow soldering, and the temperature of the soldering furnace is high, which is likely to cause deformation of the circuit board. Affect the quality of the board.

Therefore, it is necessary to provide a circuit board having buried components that does not require over-reflow and has a high quality and a method of fabricating the same.

A manufacturing method of a multilayer circuit board having a buried component, comprising the steps of: providing a core circuit board, forming a through hole on the core circuit board; providing an electronic component, forming a plurality of electrodes on the electrode of the electronic component Conductive bumps, each of the conductive bumps gradually decreasing in cross-sectional area from the electrode toward the electrode; the electronic component after forming the conductive bumps is received in the core layer a film and a copper foil are sequentially laminated on the mounting holes of the circuit board, and the core circuit board is bonded to each of the copper foils through one of the films. And each of the conductive bumps is penetrated through a film and is in contact with and electrically connected to the copper foil attached to the film to form a circuit substrate; each of the copper foils is formed to form a conductive line a layer electrically connecting the electronic component to the conductive circuit layer to form the multilayer circuit board having the embedded component.

A multilayer circuit board having embedded components, comprising a core circuit board, an electronic component, a first film, a second film, and a conductive circuit layer. A through hole is formed in the core layer circuit board. The electronic component is housed in the mounting hole. A plurality of conductive bumps are formed on the electrodes of the electronic component, and a cross-sectional area of each of the conductive bumps in a direction away from the electrodes toward the electrodes is gradually reduced. The first film and the second film are respectively formed on opposite sides of the core circuit board, and the plurality of conductive bumps penetrate the first film. The conductive circuit layers are formed on the first film and the second film surface, respectively. The conductive bumps penetrating the first film are in contact with and electrically connected to a conductive circuit layer attached to the first film.

Compared with the prior art, the multi-layer circuit board with embedded components of the embodiment of the present invention and the manufacturing method thereof enable the conductive bump to pierce the film and the conductive circuit layer by forming a conductive bump having a tip on the electronic component. The electrical connection allows the electronic components to be buried, and does not require over-reflow, which can reduce the problem of circuit board warpage, shrinkage mismatch, etc. caused by reflow, thereby improving the board production yield.

100‧‧‧Multilayer boards with embedded components

10‧‧‧core circuit board

17‧‧‧Electronic parts

181‧‧‧first film

191‧‧‧second film

22‧‧‧ Third conductive circuit layer

23‧‧‧fourth conductive layer

11‧‧‧Substrate layer

121‧‧‧First conductive circuit layer

131‧‧‧Second conductive circuit layer

141‧‧‧ conductive through holes

16‧‧‧Installation holes

173‧‧‧ Main body

171‧‧‧electrode

1711‧‧‧ upper surface

1712‧‧‧ lower surface

172‧‧‧Electrical bumps

24‧‧‧First conductive blind hole

25‧‧‧Second conductive blind hole

27‧‧‧ Third film

28‧‧‧ Fifth conductive circuit layer

29‧‧‧Fourth film

30‧‧‧ sixth conductive circuit layer

12‧‧‧First conductive layer

13‧‧‧Second conductive layer

14‧‧‧Line area

15‧‧‧Parts installation area

18‧‧‧First layered material

19‧‧‧Second layered material

20‧‧‧Multilayer structure

182‧‧‧First copper foil

192‧‧‧second copper foil

26‧‧‧Four-layer circuit board with embedded components

31‧‧‧ Third conductive blind hole

32‧‧‧4th conductive blind hole

1 is a cross-sectional view of a multilayer circuit board having embedded components according to a first embodiment of the present invention.

2 is a cross-sectional view showing a core layer circuit board according to a second embodiment of the present invention.

Fig. 3 is a cross-sectional view showing the mounting hole formed on the core circuit board of Fig. 2.

4 is a cross-sectional view showing the formation of conductive bumps on an electronic component in a second embodiment of the present invention.

5 is a cross-sectional view showing the electronic component of FIG. 4 housed in a mounting hole in the core layer circuit board of FIG. 3 and laminated on the both sides of the core circuit board to form a stacked structure.

Fig. 6 is a cross-sectional view showing the laminated structure of Fig. 5 pressed to form a circuit substrate.

Fig. 7 is a cross-sectional view showing the copper foil of Fig. 6 after forming a conductive circuit layer to obtain four layers of a circuit board having embedded elements.

Referring to FIG. 1, a first embodiment of the present invention provides a multilayer circuit board 100 having embedded components, including: a core circuit board 10, electronic components 17 received in the core circuit board 10, and a core circuit. A first film 181 and a second film 191 on both sides of the board 10, a third conductive wiring layer 22 formed on the first film 181 side, and a fourth conductive wiring layer 23 formed on the second film 191 side.

The core layer circuit board 10 includes a substrate layer 11 and a first conductive circuit layer 121 and a second conductive circuit layer 131 disposed on opposite sides of the substrate layer 11, and a conductive via 141 electrically connects the first conductive layer The wiring layer 121 and the second conductive wiring layer 131 have a mounting hole 16 penetrating the core circuit board 10.

The electronic component 17 is received in the mounting hole 16 . The electronic component 17 includes a body portion 173 and an electrode 171, and the thickness of the electronic component 17 is equal to or slightly smaller than the depth of the mounting hole 16. The main body portion 173 is substantially rectangular, and the two electrodes 171 are formed at both ends of the main body portion 173 in the longitudinal direction. The two electrodes 171 each include an upper surface 1711 and opposite the upper surface 1711. a lower surface 1712, two of the upper surfaces 1711 are located on the same side of the electronic component 17, two lower surfaces 1712 are located on opposite sides of the electronic component 17, and an upper surface 1711 of the two electrodes 171 Conductive bumps 172 are formed on the lower surface 1712. The conductive bumps 172 protrude in a direction perpendicular to the core circuit board 10. The conductive bump 172 gradually decreases in cross-sectional area from the electrode 171 in a direction away from the electrode 171.

At least one first conductive blind hole 24 is formed in the first film 181, at least one second conductive blind hole 25 is formed in the second film 191, and the first conductive blind hole 24 is electrically connected to the first The conductive circuit layer 121 and the third conductive circuit layer 22 are electrically connected to the second conductive circuit layer 131 and the fourth conductive circuit layer 23. The conductive bumps 172 on both sides of the electronic component 17 respectively penetrate the first and second films 181 and 191 and are electrically connected to the third and fourth conductive circuit layers 22 and 23, respectively.

A third film 27 and a fifth conductive circuit layer 28 are sequentially formed on the third conductive circuit layer 22 side, and a fourth film 29 and a sixth conductive circuit layer 30 are sequentially formed on the fourth conductive circuit layer 23 side. A third conductive blind hole 31 and a fourth conductive blind hole 32 are formed in the third film 27 and the fourth film 29, and the third conductive blind hole 31 electrically connects the third conductive circuit layer 22 with the The fifth conductive circuit layer 28 electrically connects the fourth conductive circuit layer 23 and the sixth conductive circuit layer 30.

Referring to FIG. 2-7 together, a second embodiment of the present invention provides a method for fabricating the above-described multilayer circuit board 100 having embedded components, including the following steps:

In the first step, referring to FIG. 2, a core circuit board 10 is provided. The core circuit board 10 includes a substrate layer 11, and first conductive layers 12 and second conductive electrodes disposed on opposite sides of the substrate layer 11. Layer 13.

In this embodiment, a circuit board unit of the core circuit board 10 is taken as an example. The core circuit board 10 defines a line area 14 and a component mounting area 15. The part mounting area 15 is approximately the same size as the part to be mounted. The first conductive layer 12 and the second conductive layer 13 in the line region 14 are all conductive circuit layers formed with conductive lines, and the first conductive layer 12 and the second conductive layer 13 in the line region 14 are defined. The first conductive circuit layer 121 and the second conductive circuit layer 131 are respectively. The core circuit board 10 is further formed with at least one conductive via 141 in the line region 14 , and the conductive via 141 electrically connects the first conductive wiring layer 121 and the second conductive wiring layer 131 . The first conductive layer 12 and the second conductive layer 13 in the component mounting region 15 do not form conductive lines, and are disconnected from the first conductive layer 12 and the second conductive layer 13 in the wiring region 14, respectively. In another embodiment, within the part mounting area 15 The first conductive layer 12 and the second conductive layer 13 may not be disconnected from the first conductive layer 12 and the second conductive layer 13 in the line region 14. In other embodiments, the first conductive layer 12 and the second conductive layer 13 may not be formed in the component mounting region 15 .

In this embodiment, the materials of the first conductive layer 12 and the second conductive layer 13 are all copper. In the embodiment, the substrate layer 11 is an insulating layer, that is, the core circuit board 10 is a double-sided circuit board. In other embodiments, the substrate layer 11 may also include a plurality of insulating layers and conductive circuit layers. In this case, the insulating layer and the conductive circuit layer are alternately arranged, and the outermost sides of the substrate layer 11 are insulating layers, that is, In other embodiments, the core circuit board 10 can also be a multi-layer circuit board. In other embodiments, the number of component mounting regions 15 may also be plural; the core circuit board 10 may include a plurality of circuit board units.

In the second step, referring to FIG. 3, the core circuit board 10 in the component mounting area 15 is removed, thereby forming a mounting hole 16 in the core circuit board 10.

In the embodiment, the core circuit board 10 is cut along the boundary line between the line area 14 and the component mounting area 15 by laser cutting, thereby removing the core layer circuit in the component mounting area 15. Board 10. The mounting hole 16 extends through the core circuit board 10 for receiving an electronic component. In the present embodiment, the first conductive layer 12 and the second conductive layer 13 in the component mounting region 15 are disconnected from the first conductive layer 12 and the second conductive layer 13 in the wiring region 14, respectively. Therefore, only the substrate layer 11 is cut during cutting without cutting into the conductive layer, which is easier to cut. In other embodiments, the mounting hole 16 may also be formed by punching, fishing, or the like.

In a third step, referring to FIG. 4, an electronic component 17 is provided. On the electrode 171 of the electronic component 17, a conductive bump 172 is formed. The conductive bump 172 is in a direction away from the electrode 171 away from the electrode 171. The cross-sectional area is gradually reduced.

In the embodiment, the electronic component 17 includes a main body portion 173 and two electrodes 171. The main body portion 173 is substantially rectangular, and the two electrodes 171 are formed at both ends of the main body portion 173 in the longitudinal direction. The two electrodes 171 each include an upper surface 1711 and opposite the upper surface 1711. lower surface 1712, two of the upper surfaces 1711 are located on the same side of the electronic component 17, and the two lower surfaces 1712 are located on opposite sides of the electronic component 17. The number of the conductive bumps 172 is four, which are respectively formed on the upper surface 1711 and the lower surface 1712 of the two electrodes 171. The thickness of the electronic component 17 is equal to or slightly smaller than the depth of the mounting hole 16.

Forming the conductive bumps 172 on the electrodes 171 of the electronic component 17 includes the steps of: first, forming a conductive paste on the upper surface 1711 and the lower surface 1712 of each of the electrodes 171 of the electronic component 17 by printing. The conductive paste may be a silver paste, a copper paste or the like; secondly, the conductive paste is cured to obtain the conductive bump 172, and the conductive bump 172 is in a cross section away from the electrode 171 in a direction away from the electrode 171. The area of the conductive bumps 172 may be a conical shape, a truncated cone shape, a triangular pyramid shape, a triangular prism shape, a polygonal pyramid shape, a polygonal prism shape, or the like.

In other embodiments, the conductive bumps 172 may also be formed only on the upper surface 1711 or only on the lower surface 1712; the number of the conductive bumps 172 is not limited to the embodiment. For example, two or more conductive bumps 172 may be formed on the upper surface 1711 and the lower surface 1712 of each of the electrodes 171.

In the fourth step, referring to FIG. 5, the electronic component 17 after the conductive bumps 172 are formed is received in the mounting holes 16 of the core circuit board 10, and stacked on both sides of the core circuit board 10. The first build-up material 18 and the second build-up material 19 are combined such that the conductive bumps 172 of the electronic component 17 are in contact with the build-up material to form a stack structure 20.

In this embodiment, the first build-up material 18 includes a first film 181 and a first copper foil 182, and the second build-up material 19 includes a second film 191 and a second copper foil 192. The conductive bumps 172 on both sides of the electronic component 17 are in direct contact with the first and film 181, 191, respectively. The first and second films 181, 191 may be semi-cured insulating resin sheets, and may include a toughened material such as a glass cloth. The thicknesses of the first film 181 and the second film 191 are substantially the same as the height of the conductive bumps 172 in contact with the core layer circuit board 10, respectively.

In this embodiment, the step of forming the laminated structure 20 includes: firstly providing the first film 181, and pre-bonding the first film to the core circuit board 10 by rolling Side, that is, the one end opening of the mounting hole 16 is closed by the first film 181; after that, the electronic component 17 after the conductive bump 172 is formed is received in the mounting hole 16 of the core circuit board 10. And supporting the conductive bump 172 on one side of the electronic component 17 on the first film 181; then, superimposing the side of the first film 181 away from the core circuit board 10 The first copper foil 182 sequentially overlaps the second film 191 and the second copper foil 192 on the side of the core circuit board 10 away from the first film 181, thereby forming the stacked structure 20.

In a fifth step, referring to FIG. 6, the laminated structure 20 is pressed, the core circuit board 10 is bonded to the first build-up material 18 and the second build-up material 19, and the electrons are bonded. The conductive bumps 172 on both sides of the component 17 respectively penetrate the first and second films 181, 191 and are electrically connected to the copper foil on the same side, thereby forming a circuit substrate 21.

In this embodiment, the conductive bump 172 gradually decreases in cross-sectional area from the electrode 171 in a direction away from the electrode 171, that is, has a sharp end, so under pressure, the The conductive bump 172 can pierce the first film 181 and the second film 191 to be electrically connected to the first and second copper foils 182, 192, and the thickness of the first film 181 and the second film 191 The conductive bumps 172 in contact therewith protrude substantially the same height of the core circuit board 10, so the conductive bumps 172 can be electrically connected to the first and second copper foils 182, 192 without puncturing. The first and second copper foils 182, 192 are worn.

In a sixth step, referring to FIG. 7, the first copper foil 182 is formed into a third conductive wiring layer 22, and the second copper foil 192 is formed into a fourth conductive wiring layer 23, and in the first film. Forming at least one first conductive blind via 24 in the 181, forming at least one second conductive via 25 in the second film 191, electrically connecting the first conductive via 24 to the first conductive trace layer 121 The third conductive circuit layer 22 electrically connects the second conductive via hole 25 to the second conductive circuit layer 131 and the fourth conductive circuit layer 23, and electrically connecting the conductive bumps 172 on both sides of the electronic component 17 to the conductive circuit layer on the same side, that is, the electronic component 17 and the third and fourth conductive lines The layers 22, 23 are electrically connected to each other to obtain a four-layer circuit board 26 having embedded components.

In this embodiment, the conductive via hole and the conductive circuit layer may be formed by: firstly forming at least one blind via on the first film 181 and the first copper foil 182 by laser ablation, and in the Forming at least one blind hole on the second film 191 and the second copper foil 192; then, plating is formed on the wall of the blind hole to form a plating layer, thereby forming the blind hole to form the first conductive blind hole 24 and the second conductive blind Hole 25; Finally, the first copper foil 182 is formed into a third conductive wiring layer 22 by an image transfer process and an etching process, and the second copper foil 192 is formed into a fourth conductive wiring layer 23.

In the seventh step, please refer to FIG. 1 to add layers on both sides of the four-layer circuit board 26 with embedded components to form a third film 27 and a fifth conductive circuit layer 28, a fourth film 29 and a first a sixth conductive circuit layer 30, and a third conductive blind hole 31 and a fourth conductive blind hole 32 are respectively formed in the third film 27 and the fourth film 29, so that the third conductive blind hole 31 is electrically connected to the The third conductive circuit layer 22 and the fifth conductive circuit layer 28 electrically connect the fourth conductive blind via 32 to the fourth conductive trace layer 23 and the sixth conductive trace layer 30, thereby obtaining a buried Multilayer circuit board 100 of components.

In this step, the layering method is similar to the fourth to sixth steps, that is, the film and the copper foil are first pressed, and then the conductive blind holes are formed in the film, and finally the copper foil is made into a conductive line. Of course, if only four layers of boards need to be formed, this step is not required.

It can be understood that a solder resist layer can also be formed on the multilayer circuit board 100 having the embedded component to protect the exposed conductive lines on the outermost sides; the multilayer circuit board of the present invention can also form more in the seventh step manner. The conductive wiring layer thus results in a multilayer circuit board 100 having embedded components including more layers of wiring layers.

Compared with the prior art, the multilayer circuit board 100 having the embedded component of the embodiment of the present invention and the manufacturing method thereof are formed by forming the conductive bump 172 having the tip on the electronic component 17 to make the conductive bump thorn The film is electrically connected to the conductive circuit layer, thereby burying the electronic component 17 and eliminating the need for over-reflow, which can reduce the problem of circuit board warpage, shrinkage mismatch, etc. caused by reflow, thereby improving the board fabrication yield. .

However, the above description is only a preferred embodiment of the present invention, and the claim of the present invention cannot be limited thereby. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included in the following claims.

100‧‧‧Multilayer boards with embedded components

10‧‧‧core circuit board

17‧‧‧Electronic parts

181‧‧‧first film

191‧‧‧second film

22‧‧‧ Third conductive circuit layer

23‧‧‧fourth conductive layer

11‧‧‧Substrate layer

121‧‧‧First conductive circuit layer

131‧‧‧Second conductive circuit layer

141‧‧‧ conductive through holes

16‧‧‧Installation holes

173‧‧‧ Main body

171‧‧‧electrode

1711‧‧‧ upper surface

172‧‧‧Electrical bumps

24‧‧‧First conductive blind hole

25‧‧‧Second conductive blind hole

27‧‧‧ Third film

28‧‧‧ Fifth conductive circuit layer

29‧‧‧Fourth film

30‧‧‧ sixth conductive circuit layer

31‧‧‧ Third conductive blind hole

32‧‧‧4th conductive blind hole

Claims (15)

A manufacturing method of a multilayer circuit board having a buried component, comprising the steps of: providing a core circuit board, forming a through mounting hole on the core circuit board; providing an electronic component, the thickness of the electronic component being equal to or slightly smaller a depth of the mounting hole, printing a conductive paste on the electrode of the electronic component, and curing the conductive paste to obtain a plurality of conductive bumps, each of the conductive bumps being in a direction away from the electrode from the electrode The cross-sectional area of the upper portion is gradually reduced; the electronic component after the conductive bump is formed is received in the mounting hole of the core circuit board, and the film and the copper foil are sequentially laminated on both sides of the core circuit board Pressing to bond the core circuit board to each of the copper foils through one of the films, the thickness of each of the films being substantially the same as the height of the conductive bumps protruding from the core circuit board And each of the conductive bumps is penetrated through a film and is in contact with and electrically connected to the copper foil attached to the film to form a circuit substrate; each of the copper foils is formed to form a conductive Circuit layer The electronic component and the conductive wiring layer electrically connected to form a multilayer circuit board having a buried element. The method of fabricating a multilayer circuit board having a buried component according to claim 1, wherein the mounting hole is formed on the core layer circuit board by laser cutting, punching or scribing. The method of fabricating a multilayer circuit board having a buried component according to claim 1, wherein the core circuit board comprises a substrate layer and a first conductive circuit layer disposed on opposite sides of the substrate layer and a conductive circuit layer, the core circuit board includes a circuit area and a component mounting area, the first conductive circuit layer and the second conductive circuit layer are formed only in the circuit area, along the line area and the The boundary layer of the component mounting area cuts the core circuit board to remove the core circuit board in the component mounting area to form the mounting hole. The method of fabricating a multilayer circuit board having a buried component according to claim 1, wherein the core circuit board comprises a substrate layer and a first conductive layer and a second layer disposed on opposite sides of the substrate layer a conductive layer, the core circuit board includes a line region and a component mounting region, the first conductive layer and the second conductive layer in the circuit region and the first conductive region in the component mounting region The layer and the second conductive layer are disconnected, and the first conductive layer and the second conductive layer of the line region are respectively a first conductive circuit layer and a second conductive circuit layer, and are installed along the circuit region and the component The boundary line of the region cuts the core circuit board to remove the core circuit board in the component mounting area to form the mounting hole. The method for fabricating a multilayer circuit board having a buried component according to claim 1, wherein the conductive paste is a silver paste or a copper paste. The method for fabricating a multilayer circuit board having a buried component according to claim 1, wherein the conductive bump has a conical shape, a truncated cone shape, a triangular pyramid shape, a triangular prism shape, and a polygonal pyramid shape. Or multi-segmented. The method of fabricating a multi-layer circuit board having a buried component according to claim 1, wherein the electronic component comprises a main body portion and two electrodes, the two electrodes each including a lower surface, two of the lower The surface is located on the same side of the electronic component, and the lower surface of each of the electrodes is formed with at least one conductive bump. When the film is pressed, each of the conductive bumps penetrates the film on one side of the core circuit board And electrically connected to the copper foil attached to the film. The method of fabricating a multilayer circuit board having a buried component according to claim 7, wherein the two electrodes further include an upper surface opposite to the lower surface, and the two upper surfaces are located on the electronic component On the opposite side, the upper surface of each of the electrodes is also formed with at least one conductive bump. When the film is pressed, each of the conductive bumps respectively penetrates the film on the same side and is attached to the film. The copper foil is electrically connected. The manufacturing method of the multi-layer circuit board with embedded components according to Item 8, wherein the number of the conductive bumps is four, and the conductive bumps are respectively formed on the upper surfaces of the two electrodes. And the lower surface. The method of manufacturing a multilayer circuit board having a buried component according to claim 8, wherein the electronic component after forming the conductive bump is received in a mounting hole of the core circuit board, and The step of sequentially laminating the film and the copper foil on both sides of the core layer circuit board includes: providing a first film, and pre-bonding the first film to one side of the core circuit board by rolling, Afterwards, the electronic component after forming the conductive bump is received in the mounting hole of the core circuit board, and the conductive bump on one side of the electronic component is supported on the first film, and then The first film is overlapped with the first copper foil on a side of the core circuit board, and the second film and the first film are stacked on a side of the core circuit board away from the first film. Second copper foil. The method for fabricating a multilayer circuit board having embedded components according to claim 1, wherein after each of the copper foils is formed into a conductive circuit layer, the surface of each of the conductive circuit layers is further increased. The steps of the layer. A multilayer circuit board having buried components, comprising: a core layer circuit board having a through mounting hole formed therein; an electronic component, the electronic component being received in the mounting hole, the electronic component having a thickness equal to or slightly smaller than the mounting hole a depth, a plurality of conductive bumps formed on the electrodes of the electronic component, the plurality of conductive bumps being formed by curing of the conductive paste, each of the conductive bumps having a cross section in a direction away from the electrode toward the electrode The area is gradually reduced; the first film and the second film formed on opposite sides of the core circuit board, the plurality of conductive bumps penetrating through the first film; and the first film and the second film respectively formed a conductive circuit layer on the surface of the film, the conductive bump extending through the first film is in contact with and electrically connected to a conductive circuit layer attached to the first film. The multi-layer circuit board with embedded components of claim 12, wherein a plurality of conductive bumps extend through the second film, the conductive bumps penetrating the second film, and the first film The attached conductive circuit layers are electrically connected. The multi-layer circuit board with a buried component according to claim 12, wherein the electronic component comprises a main body portion and two electrodes, each of the two electrodes including a lower surface and an upper surface opposite to the lower surface a surface, two lower surfaces are located on the same side of the electronic component, two of the upper surfaces are located on opposite sides of the electronic component, and the number of the conductive bumps is four, the conductive bump Formed on the upper surface and the lower surface of the two electrodes, respectively. The multilayer circuit board with a buried component according to claim 12, wherein the conductive bump has a conical shape, a truncated cone shape, a triangular pyramid shape, a triangular prism shape, a polygonal pyramid shape or a polygonal edge. Table shape.