CN110809358B

CN110809358B - Heat dissipation PCB and manufacturing method thereof

Info

Publication number: CN110809358B
Application number: CN201911017143.2A
Authority: CN
Inventors: 李泰巍; 林楚涛; 王盼; 陈育金; 李艳国
Original assignee: Shenzhen Fastprint Circuit Tech Co Ltd; Guangzhou Fastprint Circuit Technology Co Ltd; Yixing Silicon Valley Electronic Technology Co Ltd
Current assignee: Shenzhen Fastprint Circuit Tech Co Ltd; Guangzhou Fastprint Circuit Technology Co Ltd; Yixing Silicon Valley Electronic Technology Co Ltd
Priority date: 2019-10-24
Filing date: 2019-10-24
Publication date: 2021-07-20
Anticipated expiration: 2039-10-24
Also published as: CN110809358A

Abstract

The invention relates to a heat dissipation PCB and a manufacturing method thereof, wherein the manufacturing method of the heat dissipation PCB comprises the following steps: preparing a plurality of layers of core plates, wherein prepregs are arranged between adjacent layers of core plates; a through groove is formed in at least one layer of core board and the prepreg which are positioned in the inner layer, and the heat dissipation conductor is embedded into the through groove in a glue flowing bonding mode; opening the covers at the positions corresponding to the heat dissipation conductors on the other core plates and the prepregs; electroplating and copper plating are carried out on the basis of the heat dissipation conductor. Utilize the characteristic that inlayer embedding heat dissipation conductor can electroplate, carry out the selectivity on heat dissipation conductor's basis and add the plating, make it and external contact to increased heat radiating area, improved the radiating effect, the heat dissipation conductor who is located the inlayer is tightly wrapped up by outer copper facing moreover, can effectively avoid the direct not enough problem of reliability of outer embedding conductor.

Description

Heat dissipation PCB and manufacturing method thereof

Technical Field

The invention relates to a manufacturing technology of a circuit board, in particular to a heat dissipation PCB and a manufacturing method thereof.

Background

The PCB can generate a large amount of heat energy due to the electrical functionality, and the PCB has high requirements on heat dissipation performance in order to ensure that the product can be used durably and stably. However, the HDI (High Density interconnect) structure product does not achieve a good effect in heat dissipation due to its particularity. The product of a general HDI structure can only achieve the heat dissipation effect through an externally-embedded copper block or through laser drilling, but the former has the risk of insufficient reliability due to low glue content of an outer-layer prepreg; the latter has a much reduced heat dissipation effect due to the limitations of the laser blind holes.

Disclosure of Invention

Based on the above, the application provides the heat dissipation PCB and the manufacturing method thereof, which not only have good heat dissipation effect, but also can ensure reliability.

A manufacturing method of a heat dissipation PCB comprises the following steps:

preparing a plurality of layers of core plates, wherein prepregs are arranged between adjacent layers of core plates;

a through groove is formed in at least one layer of core board and the prepreg which are positioned in the inner layer, and the heat dissipation conductor is embedded into the through groove in a glue flowing bonding mode;

opening the covers at the positions corresponding to the heat dissipation conductors on the other core plates and the prepregs;

electroplating and copper plating are carried out on the basis of the heat dissipation conductor.

According to the manufacturing method of the heat dissipation PCB, the characteristic that the inner layer embedded heat dissipation conductor can be electroplated is utilized, selective plating is carried out on the basis of the heat dissipation conductor, the heat dissipation conductor is in contact with the outside, the heat dissipation area is increased, the heat dissipation effect is improved, the heat dissipation conductor positioned on the inner layer is tightly wrapped by the outer layer of copper plating, and the problem that the reliability of the conductor directly embedded on the outer layer is insufficient can be effectively solved.

In one embodiment, the step of "forming a through groove in at least one core board and a prepreg located in an inner layer, and embedding the heat dissipation conductor into the through groove by using a flow adhesive bonding manner" specifically includes the following steps:

and (3) opening a through groove in two adjacent core plates positioned in the inner layer and the prepreg positioned between the two core plates, embedding the heat dissipation conductor into the through groove, laminating the two core plates and the prepreg positioned between the two core plates to form a daughter board, and bonding the heat dissipation conductor in the through groove through the gummosis of the prepreg.

In one embodiment, the step of uncovering the positions corresponding to the heat dissipation conductors on the other core boards and the prepregs specifically includes the following steps:

uncovering positions, corresponding to the heat dissipation conductors, of the upper prepreg and the lower prepreg adjacent to the daughter board;

laminating and bonding the core board and the prepreg which are positioned above the daughter board, and the core board and the prepreg which are positioned below the daughter board to form a mother board;

and opening the cover of the position of the motherboard corresponding to the heat dissipation conductor.

opening the cover of the positions, corresponding to the heat dissipation conductors, of the upper prepreg and the lower prepreg adjacent to the daughter board by adopting laser or a mechanical milling cutter;

and opening the cover of the position, corresponding to the heat dissipation conductor, on the motherboard by adopting laser or a mechanical milling cutter.

and opening the cover of the position corresponding to the heat dissipation conductor on the motherboard by a laser grooving process.

In one embodiment, the step of "plating copper on the basis of the heat dissipation conductor" includes the following steps:

attaching a selective plating dry film on the outermost layer of the mother board after the cover is opened, and windowing the region of the selective plating dry film corresponding to the heat dissipation conductor;

and then electroplating and copper plating are carried out until the uncapped area of the mother board is filled with the electroplated copper blocks.

In one embodiment, after the electroplating and the copper plating are completed, film stripping treatment is performed, and the surface of the electroplated copper block is polished.

In one embodiment, the width of the uncapped region is 0.1mm to 0.15mm smaller than the width of the heat dissipation conductor; the width of the windowing area on the selective plating dry film is 0.05mm-0.1mm smaller than the width of the uncapping area.

In one embodiment, the width of the through groove is 0.1mm-0.2mm larger than that of the heat dissipation conductor; the heat dissipation conductor is a copper block.

A heat dissipation PCB board comprises heat dissipation conductors and a plurality of layers of core boards, wherein adjacent layers of core boards are bonded through prepregs, at least one layer of core board and prepregs positioned in the inner layer are provided with through grooves, the heat dissipation conductors are embedded in the through grooves, areas, corresponding to the heat dissipation conductors, of other core boards and prepregs which are not provided with the through grooves are uncovered, and the uncovered areas are filled with copper plating on the basis of the heat dissipation conductors.

Above-mentioned heat dissipation PCB board utilizes the characteristic that inlayer embedding heat dissipation conductor can electroplate, carries out the selectivity on heat dissipation conductor's basis and adds the plating, makes it and external contact to increased heat radiating area, improved the radiating effect, the heat dissipation conductor who is located the inlayer moreover is tightly wrapped up by outer copper facing, can effectively avoid directly the not enough problem of reliability at the inlayer embedding conductor.

Drawings

Fig. 1 is a schematic diagram of a step S200 of a method for manufacturing a heat dissipation PCB according to an embodiment of the present application;

fig. 2 is a schematic diagram of a step S300 of a method for manufacturing a heat dissipation PCB according to an embodiment of the present application;

fig. 3 is a schematic diagram of step S300 of a method for manufacturing a heat dissipation PCB according to another embodiment of the present application;

fig. 4 is a schematic diagram of step S400 of a method for manufacturing a heat dissipation PCB according to another embodiment of the present application.

Description of reference numerals:

10. the circuit board comprises a core board, 102, a dielectric layer, 104, a circuit layer, 20, a prepreg, 30, a heat dissipation conductor, 40, copper plating, 50, a selective plating dry film, 510, a window, 110, a through groove, 120, a cover opening, 200, a daughter board, 300 and a mother board.

Detailed Description

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present.

Referring to fig. 1-4, an embodiment of the present application provides a method for manufacturing a heat dissipation PCB, including the following steps: s100, preparing a multilayer core board 10, and arranging prepregs 20 between adjacent layers of the core board 10. And S200, forming a through groove 110 in at least one layer of the core board 10 and the prepreg 20 positioned in the inner layer, and embedding the heat dissipation conductor 30 into the through groove 110 in a glue flowing bonding mode. And S300, opening the cover 120 at the position corresponding to the heat dissipation conductor 30 on the other core boards 10 and the prepregs 20. S400, electroplating and copper plating 40 is carried out on the basis of the heat radiation conductor 30.

The manufacturing method of the heat dissipation PCB board of the embodiment utilizes the characteristic that the inner embedded heat dissipation conductor 30 can be electroplated, and selectively plates on the basis of the heat dissipation conductor 30 to enable the heat dissipation conductor to be in contact with the outside, increases the heat dissipation area, improves the heat dissipation effect, and the heat dissipation conductor 30 positioned on the inner layer is tightly wrapped by the outer copper plating 40, so that the problem of insufficient reliability of the conductor directly embedded on the outer layer can be effectively avoided.

Referring to fig. 2-4, in this embodiment, a four-layer core 10 and a three-layer prepreg 20 are used. The core board 10 includes a dielectric layer 102 in the middle and circuit layers 104 on both sides of the dielectric layer 102. In other embodiments, the core board 10 and the prepregs 20 with the corresponding number of layers, such as five core boards 10 and four prepregs 20, may be prepared according to actual production requirements.

Referring to fig. 1, in an embodiment, step S200 specifically includes: the through groove 110 is formed in two adjacent core boards 10 located in the inner layer and the prepreg 20 located between the two core boards 10, the heat dissipation conductor 30 is embedded into the through groove 110, the two core boards 10 and the prepreg 20 located between the two core boards 10 are laminated to form the daughter board 200, and the heat dissipation conductor 30 is bonded in the through groove 110 through the flowing glue of the prepreg 20. In other embodiments, the through groove 110 may be formed only in one layer of the core board 10 and the adjacent prepreg 20, and the core board 10 on the other side of the prepreg 20 is not provided with the through groove 110; or the through groove 110 is opened on the prepreg 20 between three adjacent core boards 10 and each core board 10, and the heat dissipation conductor 30 with the corresponding height is embedded in the through groove 110. The heat dissipation conductor 30 may be embedded and bonded by the prepreg 20 in the inner layer. During the lamination process, the prepreg 20 melts to form a flowing glue, so that the heat dissipation conductor 30 is primarily bonded to the inner layer.

Referring to fig. 2 to 4, in the present embodiment, a groove 110 is formed in the second core board, the second prepreg, and the third core board, and the heat dissipation conductor 30 is embedded in the groove 110.

Optionally, the width of the through groove 110 is 0.1mm to 0.2mm wider than the heat dissipation conductor 30, so that the heat dissipation conductor 30 can be smoothly inserted into the through groove 110. The heat dissipation conductor 30 is a copper block, and other metal blocks, such as an iron block and an aluminum block, can be selected for the heat dissipation conductor 30 according to production requirements.

Referring to fig. 2, in one embodiment, step S300 specifically includes the following steps:

s310: the cover 120 is opened at a position corresponding to the heat dissipation conductor 30 on the upper and lower prepregs 20 adjacent to the sub-board 200. Alternatively, the cover opening 120 may be performed by using a laser or a mechanical milling cutter on the positions of the upper and lower prepregs 20 adjacent to the daughter board 200, which correspond to the heat dissipation conductors 30.

S320: and laminating and bonding the core board 10 and the prepreg 20 positioned above the daughter board 200, the daughter board 200 and the core board 10 and the prepreg 20 positioned below the daughter board 200 to form the mother board 300.

S330: the motherboard 300 is uncapped 120 at a position corresponding to the heat dissipation conductor 30. Alternatively, the cover 120 may be opened by laser or mechanical milling at the position corresponding to the heat dissipation conductor 30 on the motherboard 300.

The uncovering 120 is to remove the positions corresponding to the heat dissipation conductors 30 on the core board 10 and the prepreg 20 without the through groove 110.

In the above embodiment, the cover 120 is performed on the prepreg 20 adjacent to the outer layer of the daughter board 200 in advance, then the prepreg 20 with the cover 120 is stacked with the core boards 10 and the prepregs 20 of other un-opened slots 110 and the daughter board 200 according to the predetermined arrangement sequence, and laminated to form the mother board 300, and finally the cover 120 is performed on the un-opened core boards 120 or the slotted core boards 10 and the prepregs 20 on the mother board 300, where the position of the cover 120 corresponds to the heat dissipation conductor 30, so that the cover 120 is communicated with the area of the cover 120 of the prepreg 20 with the cover 120. By the method, the situation that when the motherboard 300 is directly uncapped 120, the prepreg 20 adjacent to the daughter board 200 is melted can be avoided, so that the board in the area where the motherboard 300 is uncapped 120 is stuck on the daughter board 200 and cannot be removed.

Referring to fig. 3, in another embodiment, step S300 specifically includes the following steps:

and S301, laminating and bonding the core board 10 and the prepreg 20 above the daughter board 200, the daughter board 200 and the core board 10 and the prepreg 20 below the daughter board 200 to form the mother board 300.

And S302, opening the cover 120 of the motherboard 300 at the position corresponding to the heat dissipation conductor 30 by a laser grooving process.

In this embodiment, the core boards 10, the prepregs 20 and the daughter boards 200 without the through grooves 110 are directly stacked in a predetermined arrangement order to form the mother board 300 by lamination, and then the uncapped 120 or the grooved core boards 10 and the prepregs 20 on the mother board 300 are uncapped 120 by a laser grooving process, where the position of the uncapped 120 corresponds to the heat dissipation conductor 30, so that the uncapped 120 is communicated with the uncapped 120 region of the prepregs 20 with the uncapped 120. When this mode adopts laser grooving's technology directly to uncap 120 to mother board 300, the laser grooving in-process can directly burn the hole that forms with uncapping 120 region, and this mode can realize uncapping 120 fast, and work efficiency is high.

Referring to fig. 2-4, in one embodiment, step S400 specifically includes the following steps:

s410, attaching the selective plating dry film 50 on the outermost layer of the motherboard 300 after the cover 120 is opened, and windowing 510 is carried out on the region of the selective plating dry film 50 corresponding to the heat dissipation conductor 30. The windowing 510 is to remove the position corresponding to the heat dissipation conductor 30 on the selective plating dry film 50.

And S420, electroplating and copper plating 40 are carried out until the electroplated copper 40 blocks fill the area of the cover opening 120 of the motherboard 300.

The selective plating dry film 50 is firstly pasted on the outermost layer of the mother board 300, meanwhile, the window 510 is opened on the area of the selective plating dry film 50 corresponding to the heat dissipation conductor 30, then the electroplating process is carried out on the mother board 300, so that the copper plating 40 is only electroplated on the area of the cover opening 120 and cannot be electroplated on the core board 10 on the outermost layer of the mother board 300, the copper plating 40 on the area of the cover opening 120 is electroplated on the basis of the heat dissipation conductor 30, not only is attached to the surface of the heat dissipation conductor 30, but also is attached to the hole wall of the area of the cover opening 120, so that the heat dissipation conductor 30 is stably buried in the PCB, the problem of insufficient reliability caused by insufficient glue flowing is avoided, copper blocks are fully electroplated in the area of the cover opening 120 of the mother board 300, the heat in the PCB is conveniently transmitted to the copper blocks formed by electroplating through the heat dissipation conductor 30, and the heat dissipation effect is improved.

Further, after the electroplating and copper plating 40 is completed, the method also comprises a step S500 of removing the film and polishing the surface of the electroplated copper 40. And removing the dry film on the core plate 10 at the outermost layer of the mother plate 300, and polishing the surface of the copper block to obtain the flat and integrated heat dissipation copper block.

Optionally, the width of the area of the cap 120 is smaller than the width of the heat dissipation conductor 30 by 0.1mm to 0.15mm, so as to avoid the position of the cap 120 deviating from the position of the heat dissipation conductor 30. The width of the area of the window 510 on the selective plating dry film 50 is 0.05mm-0.1mm smaller than the width of the area of the cover 120, so as to avoid the deviation between the position of the window 510 and the position of the cover 120. The copper plating 40 is plated on the basis of the heat radiation conductor 30 while preventing the copper plating 40 from being plated on the core board 10 of the outer layer.

Referring to fig. 1 to 4, another embodiment of the present application provides a heat dissipation PCB, including heat dissipation conductors 30 and multiple layers of core boards 10, the core boards 10 of adjacent layers are bonded by prepregs 20, through grooves 110 are formed on at least one layer of core board 10 and prepreg 20 located in an inner layer, the heat dissipation conductors 30 are embedded in the through grooves 110, the areas of the other core boards 10 and prepregs 20 that are not provided with the through grooves 110, which correspond to the heat dissipation conductors 30, are uncovered 120, and copper plating 40 is added on the basis of the heat dissipation conductors 30 to fill up the areas of the uncovered 120.

The heat dissipation PCB of the embodiment can be manufactured by adopting the manufacturing method of the heat dissipation PCB in any embodiment, the heat dissipation PCB utilizes the characteristic that the inner embedded heat dissipation conductor 30 can be electroplated to selectively plate on the basis of the heat dissipation conductor 30, so that the heat dissipation conductor is in contact with the outside, the heat dissipation area is increased, the heat dissipation effect is improved, and the heat dissipation conductor 30 positioned on the inner layer is tightly wrapped by the outer copper plating 40, so that the problem of insufficient reliability of the outer embedded conductor can be effectively solved.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A manufacturing method of a heat dissipation PCB is characterized by comprising the following steps:

the method comprises the following steps of (1) forming a through groove on at least one layer of core board and prepreg which are positioned in an inner layer, embedding a heat dissipation conductor into the through groove in a glue flowing bonding mode, and laminating the at least one layer of core board and the prepreg to form a daughter board;

uncovering a prepreg adjacent to the outer layer of the daughter board, stacking the uncovered prepreg with other core plates and prepregs without open grooves in sequence, laminating to form a mother board, uncovering the core plates and the prepregs without uncovering or grooves on the mother board, and enabling the core plates and the prepregs to be communicated with an uncovered area of the uncovered prepregs;

2. The method for manufacturing a heat dissipation PCB according to claim 1, wherein the step of "forming a through groove in at least one core board and prepreg located in an inner layer, and embedding the heat dissipation conductor into the through groove by means of flow adhesive bonding" specifically includes the following steps:

3. The method for manufacturing a heat dissipation PCB as recited in claim 1, wherein the step of stacking the uncapped prepreg with other core boards and prepregs that are not provided with through slots in order and laminating the same to form a mother board specifically includes the following steps:

and laminating and bonding the core plate and the prepreg which are positioned above the daughter board and are not provided with the through grooves, the solidified sheets which are adjacent to the daughter board and are provided with covers at the upper layer and the lower layer, the daughter board, and the core plate and the prepreg which are positioned below the daughter board to form a mother board.

4. The method for manufacturing a heat dissipation PCB as recited in claim 1, wherein the step of uncovering a prepreg adjacent to an outer layer of the daughter board, stacking the uncovered prepreg with other core boards and prepregs without open grooves in sequence, laminating to form a mother board, uncovering the core boards and the prepregs without uncovering or grooves on the mother board to communicate with uncovering areas of the uncovered prepregs comprises the following steps:

5. The method for manufacturing a heat dissipating PCB as recited in any one of claims 1 to 4, wherein after the plating and the copper plating are completed, a film removing process is performed to polish the surface of the plated copper block.

6. The method of fabricating a heat-dissipating PCB panel as claimed in any one of claims 1 to 4, wherein the width of the open-cover region is smaller than the width of the heat-dissipating conductor by 0.1mm to 0.15 mm.

7. The method for manufacturing a heat dissipation PCB board as recited in any one of claims 1 to 4, wherein the width of the windowing region on the selective plating dry film is smaller than the width of the uncapping region by 0.05mm to 0.1 mm.

8. The method for manufacturing a heat dissipating PCB board as recited in any one of claims 1 to 4, wherein the width of the through groove is 0.1mm to 0.2mm larger than the heat dissipating conductor; the heat dissipation conductor is a copper block.

9. A heat dissipation PCB board is characterized in that the heat dissipation PCB board adopts the manufacturing method of the heat dissipation PCB board as claimed in any one of claims 1 to 4, and comprises heat dissipation conductors and a plurality of layers of core boards, wherein the core boards of adjacent layers are bonded through prepregs, at least one layer of core board and prepreg positioned in the inner layer are provided with through grooves, the heat dissipation conductors are embedded in the through grooves, the areas, corresponding to the heat dissipation conductors, of the other core boards and the prepregs without the through grooves are uncovered, and copper is plated on the basis of the heat dissipation conductors to fill the uncovered areas.