KR20170019504A - Printed circuit board and manufacturing method therof - Google Patents

Abstract

The present invention provides a heat dissipation structure in the form of a thermal bar and a conducting vias formed in a closely arrayed fashion. The present invention relates to a method of fabricating a stacked structure with a copper having a high thermal conductivity by forming a large area via a detachable core as a starting material, Is performed in two steps, thereby solving the problem encountered when filling vias of large area with copper (Cu).
The present invention provides a heat dissipation structure in which copper (Cu) having a good thermal conductivity is stacked in the form of a stacked via, and is constituted by an array of conductive vias arrayed tightly in the entire area of the heat dissipation pad, (Cu). ≪ / RTI >

Description

PRINTED CIRCUIT BOARD AND MANUFACTURING METHOD THEROF BACKGROUND OF THE INVENTION [0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for dissipating heat generated in parts or circuits in a printed circuit board (PCB) or a package substrate.

More particularly, the present invention relates to a stacked via type heat dissipation structure, and more particularly, to a method of improving the heat dissipation efficiency by increasing the proportion of copper (Cu) having a good thermal conductivity.

As the degree of circuit integration of a printed circuit board increases and the operating frequency increases, the amount of heat generated in circuits or parts of the substrate increases. Therefore, there is a need for a technique that efficiently radiates heat generated in printed circuit boards, particularly components mounted on a package substrate and circuits of various layers, into the air.

In order to radiate the heat generated by parts, a stacked via type heat dissipation structure is commonly used on a printed circuit board. To increase the amount of heat dissipation, the area of the heat dissipating via should be increased. However, if the area of the heat-dissipating via is increased, it is not easy to fill the entire via with Cu by a predetermined depth in a via fill copper plating process.

1. Korean Patent Publication No. 10-2014-0070714. 2. Korean Patent No. 1,259,854. 3. Korean Patent No. 1,205,431.

SUMMARY OF THE INVENTION Accordingly, it is a first object of the present invention to provide a method of manufacturing a heat sink via that solves the problem of heat dissipation in a printed circuit board or a package substrate.

A second object of the present invention is to provide a manufacturing method for implementing a large-area heat radiation pad in a stack-via manner in addition to the first object.

In order to achieve the above object, the present invention provides a first embodiment in the form of a thermal bar and a second embodiment in which a conducting via is formed in a closely arrayed form.

In the first embodiment of the present invention, a large area vias are formed by using a detachable core as a starting material, and a structure for facilitating heat dissipation characteristics is formed by filling and stacking copper having a high thermal conductivity. (MSAP) process is divided into two steps to solve the problems encountered when filling with copper (Cu).

According to the second embodiment of the present invention, a heat dissipation structure in which copper (Cu) having a good thermal conductivity is stacked in the form of a stacked via is formed, and an array of conductive vias tightly arranged in the entire area of the heat dissipation pad is formed. This solves the problem of filling defects when filling the area of the via with copper (Cu).

That is, in the first embodiment of the present invention, the large-area heat radiation vias are filled with Cu to improve the heat radiation characteristics, whereas the second embodiment of the present invention forms general conductive vias on the entire surface of the heat radiation pad, Increase the number of fired vias to improve heat dissipation characteristics.

The present invention efficiently radiates the heat generated in the substrate to the atmosphere. The present invention has the advantage that design freedom is given to a designer for the shape and size of a heat radiation bar for a printed circuit board that radiates high heat.

Further, by increasing the proportion of copper (Cu) having a low coefficient of thermal expansion (CTE) to the substrate relative to the amount of resin, the thermal expansion coefficient of the part to be mounted on the substrate is increased, The problem of warpage of the substrate is solved.

For reference, the coefficient of thermal expansion and thermal conductivity of Cu and resin are shown in the following table.

FIGS. 1A to 1N are process flow diagrams illustrating a method of manufacturing a heat radiation via according to a first embodiment of the present invention.
FIGS. 2A to 2D are process flow diagrams illustrating a method of manufacturing a heat radiation via according to a second embodiment of the present invention. FIG.
3 is a layout and a cross-sectional view of a heat radiation via according to the first embodiment of the present invention.
4 is a layout and a cross-sectional view of a heat radiation via according to a second embodiment of the present invention.

A first embodiment of the present invention is a method of manufacturing a semiconductor device, comprising: (a) laminating and laminating a first insulating layer and a first copper on a base copper foil of a surface of a di-stableable core; (b) etching the first copper foil to form a portion for manufacturing the heat radiation via and a portion for fabricating the conductive via to form an opening, wherein the pad size of the heat radiation via is larger than the pad size of the conductive via; (c) laser drilling the first insulating layer exposed by the opening to form a heat radiation via and a conductive via; (d) forming a first plating mask covering the conductive via region and exposing only the heat dissipative via region and performing copper plating to fill the via hole with the heat dissipating via; (e) forming a second plating mask that exposes both the energized via area and the heat dissipative via area, and performing a copper plating to simultaneously fill the top plating of the heat dissipating via filled with the copper plating and via fill for the energizing via at the same time An advancing step; And (f) forming a circuit by peeling off the second plating mask, and etching the exposed first copper by flash etching to form a circuit.

A second embodiment of the present invention is a method of manufacturing a semiconductor device, comprising: (a) laminating and laminating a first insulating layer and a first copper on a base copper foil; (b) etching the first copper foil to form a portion for manufacturing a heat radiation via and a portion for fabricating the conductive via to form an opening, wherein the heat radiation via is formed by arraying a plurality of the conductive via in a form of an array, Forming a heat dissipation via pad; (c) laser drilling the first insulating layer exposed by the opening to form a heat radiation via and a conductive via; (d) forming a plating mask exposing the conductive via region and the heat radiation via region and performing copper plating to fill the via fill; And (e) forming a circuit by peeling off the plating mask and etching the exposed first copper by flash etching to form a circuit.

Hereinafter, a method of manufacturing a heat-dissipating printed circuit board according to the present invention will be described in detail with reference to FIGS. 1 to 4.

1A to 1N are process flow diagrams illustrating a method of manufacturing a heat radiation via according to a first embodiment of the present invention. The heat radiating vias according to the first embodiment of the present invention are formed of stacked vias having a large area of the heat radiating pads and will be referred to as a thermal bar or a bar VIa.

Hereinafter, the vias for heat dissipation will be referred to as thermal vias in the specification, and vias for electrical conductivity will be referred to as energization vias.

The present invention begins with a detachable core as a starting material. The descriptable core means a structure in which a copper foil is coated on the surface of a carrier serving as a support layer, such as a carrier copper, and the carrier can be peeled off from the copper foil with a slight physical force when necessary. In another embodiment of the present invention, the support layer may be a resin layer or a film layer.

1A, a copper foil 110 is formed on a digitizable core 100, and a modified semi-additive process (MSAP) process is applied to the copper foil to form a pad 120 or a bar via pad Can be produced. The copper foil 110 will be referred to as a base copper foil on the diatomable core 100.

MSAP process is an abbreviation of modified semi-additive process. It is a method compared with a subtractive process which forms a circuit pattern by etching a copper foil. The plating process is performed on a base copper foil whose surface is exposed, After removing the plating mask, flash etching is performed to remove the base copper foil to form a circuit. The data on the MSAP method can be read in the manufacturing process by referring to the present invention's prior patent applications 1,420,088 and 1,436,827.

Referring again to FIG. 1A, the purpose of forming the Bar Via Pad 120 here is to prevent accidental penetration of the base copper foil, that is, the copper foil of 100 by the laser beam, in the subsequent laser drilling process step .

Referring to FIG. 1B, the first insulating layer 130 and the first copper foil 140 are laminated and laminated by heating and pressing. 1C, a dry film (not shown) is applied and a series of image processes such as photo, development, and etching are performed according to a predetermined circuit pattern to open the copper foil 140 on the surface, The laser drill is advanced to drill a conductive via 155 for normal electrical connection with the heat dissipation via (via 150).

At this time, since the area of the heat-dissipating vias 150 is considerably wide, it is preferable to apply a conforma laser drill method.

Next, referring to FIG. 1D, the dry film 160 is closely contacted, and a photolithography process is performed so that only the heat radiation via 150 is exposed to fabricate a plating mask. The MSAP process is performed once more using the dry film 160 on which the predetermined pattern has been transferred as a plating mask to fill the heat dissipation via 150 with the copper plating 170. [

At this time, since the area of the pad of the heat-dissipating via 150 is considerably larger than the pad area of the general energizing via 155, the amounts of copper to be plated are different from each other, and the via hole of the conductive via 155 filled in the heat dissipation via 150 simultaneously with the via fill of the conductive via 155 in the second step.

1E, in a second step, a circuit pattern for simultaneously filling the via hole 155 with the upper portion of the heat radiation via 150 is transferred to the dry film 160 to form a second plating mask do. As a preferred embodiment of the present invention, a plating mask can be fabricated again with a new dry film after peeling off the previously used dry film. Referring to FIG. 1E, there is shown a dry film 160 serving as a plating mask, and a copper plating 180 filled with an upper end of the via 150 and a common via 155 by an MSAP process.

Although the copper plating 170 filled in the heat-dissipating via 150 in the first MSAP process and the copper plating 180 further filled in the secondary MSAP process are copper (Cu) of substantially the same material, It should be noted that 170 and 180 are respectively shown.

1F, the dry film 160 is peeled off and flash etched to remove the copper foil 110, that is, the base copper foil under the plating mask, leaving only the copper plating 180, .

Referring to FIG. 1G, the second insulating layer 190 and the second copper foil 200 are laminated and heat-press laminated. 1H, the copper foil 200 is opened in accordance with a predetermined circuit pattern, and the laser drill is advanced to form the heat radiation vias 210 and the general conductive vias 215. Next, as shown in FIG. Here, a general conductive vias means a via for normal electrical connection.

Referring to FIG. 1I, a pattern is transferred to the dry film 230 so as to expose only the heat radiation vias, and a plating mask is formed. Then, the MSAP process is performed to fill the copper via 240 in the heat dissipation via hole 210 of the large area pad. Then, the dry film 230 is peeled off. Referring to FIG. 1J, the upper and lower structures A and B are obtained by separating the decoratable core.

Hereinafter, the following process will be described based on the structure A. The dry film 250 is closely adhered to both surfaces of the structure A and a predetermined pattern is transferred thereon, thereby preparing a plating mask and proceeding with the MSAP process. Referring to FIG. 1K, a filled copper plating 260 is shown as a result of the MSAP process.

Referring to FIG. 11, a circuit is formed by peeling off the dry film 250 and performing flash etching to remove the copper foil under the dry film 250. Finally, a protective coating 280 of Au / Ni or OSP is formed by printing the PSR insulation 270 (FIG. 1 m) and advancing the finish. As a result, referring to FIG. 1N, a general conductive via 310 for electrical connection with the barbia 300 having a large area for heat dissipation is manufactured and completed.

2A to 2D are process flow diagrams illustrating a method of manufacturing a heat radiation via according to a second embodiment of the present invention. The heat radiating via according to the second embodiment of the present invention is a form in which conducting vias are closely formed in an array form and is referred to as a dense via.

The heat radiating vias according to the second embodiment of the present invention are formed by arranging general conductive vias in a tight array, thereby achieving the effect of large-area heat radiating vias.

The second embodiment of the present invention also starts the process with the detachable core as the starting material. Referring to FIG. 2A, a copper foil 110 is formed on the decoratable core 100, and the insulating layer 400 and the copper foil 410 are laminated and laminated by heat pressing.

Next, referring to FIG. 2B, the copper foil 410 is opened and a heat dissipation via array is formed by a laser drilling method. An image process may be performed to open the copper foil, or a direct laser drilling method may be applied.

In the second embodiment of the present invention, since the sizes of the respective heat-dissipating vias 420 constituting the heat-dissipating via array are the same as those of the general conductive vias, unlike the case of the first embodiment, no need.

Referring to FIG. 2C, the dry film 430 is brought into close contact with the substrate, and a plating mask pattern is formed so that a portion to be formed with a heat radiation via and a portion to be made a general conductive via are simultaneously opened.

Referring to FIG. 2D, it can be seen that the MSAP process results in filling the heat dissipation via 420 with the copper plating 440. The second embodiment of the present invention is characterized in that an array is formed in a tightly arrayed manner in the heat radiation vias of a general conductive via size.

3 is a layout and a cross-sectional view of a heat radiation via according to the first embodiment of the present invention. Referring to FIG. 3, the heat radiation via according to the first embodiment of the present invention has a structure in which pads having a large area are formed in a stack shape.

4 is a layout and a cross-sectional view of a heat radiation via according to a second embodiment of the present invention. Referring to FIG. 3, the heat-dissipating via according to the second embodiment of the present invention forms a closely arrayed heat-dissipating via of a general conductive via size.

The foregoing has somewhat improved the features and technical advantages of the present invention in order to better understand the claims of the invention described below. Additional features and advantages that constitute the claims of the present invention will be described in detail below. It is to be appreciated by those skilled in the art that the disclosed concepts and specific embodiments of the invention can be used immediately as a basis for designing or modifying other structures to accomplish the invention and similar purposes.

In addition, the inventive concepts and embodiments disclosed herein may be used by those skilled in the art as a basis for modifying or designing other structures to accomplish the same purpose of the present invention. It will be apparent to those skilled in the art that various modifications, substitutions and alterations can be made hereto without departing from the spirit or scope of the invention as defined in the appended claims.

The present invention efficiently radiates the heat generated in the substrate to the atmosphere. The present invention has the advantage that design freedom is given to a designer for the shape and size of a heat radiation bar for a printed circuit board that radiates high heat. Further, by increasing the proportion of copper (Cu) having a low coefficient of thermal expansion (CTE) to the substrate relative to the amount of resin, the thermal expansion coefficient of the part to be mounted on the substrate is increased, The problem of warpage of the substrate is solved.

Claims (6)

A method of manufacturing a heat radiation via of a printed circuit board,
(a) laminating and laminating a first insulating layer and a first copper on a base copper foil of a surface of the di-stableable core;
(b) etching the first copper foil to form a portion for manufacturing the heat radiation via and a portion for fabricating the conductive via to form an opening, wherein the pad size of the heat radiation via is larger than the pad size of the conductive via;
(c) laser drilling the first insulating layer exposed by the opening to form a heat radiation via and a conductive via;
(d) forming a first plating mask covering the conductive via region and exposing only the heat dissipative via region and performing copper plating to fill the via hole with the heat dissipating via;
(e) forming a second plating mask that exposes both the energized via area and the heat dissipative via area, and performing a copper plating to simultaneously fill the top plating of the heat dissipating via filled with the copper plating and via fill for the energizing via at the same time An advancing step; And
(f) forming a circuit by peeling off the second plating mask and etching the exposed first copper by flash etching
Wherein the heat dissipation via hole is formed in the printed circuit board. The method according to claim 1, further comprising the step of forming a copper foil pad on a base copper foil of a region where the heat radiation via is to be formed, prior to the step (a). The method of claim 1, further comprising, following step (f)
(g1) laminating and laminating a second insulating layer and a second copper foil;
(g2) etching the second copper foil to form a portion for manufacturing the heat radiation via and a portion for fabricating the conductive via to form an opening;
(g3) laser drilling the second insulating layer exposed by the opening to form a heat radiation via and a conductive via;
(g4) forming a third plating mask covering the conductive via region and exposing only the heat dissipating via region, and performing copper plating to fill the via hole with the heat dissipating via;
Further comprising the steps of: 4. The method according to claim 3, wherein, following step (g4)
(h1) peeling off the third plating mask;
(h2) separating and removing the detecable core to obtain two upper and lower structures;
(h3) forming a fourth plating mask exposing both the conductive via region and the heat radiation via region, performing copper plating, and performing a via fill for the upper plating of the heat dissipating via filled with the copper plating and a via fill for the conductive via at the same time Progressive stage
(h4) forming a circuit by peeling off the fourth plating mask, and performing flash etching to etch the exposed base copper and the second copper foil
Further comprising the steps of: A method of manufacturing a heat radiation via of a printed circuit board,
(a) laminating and laminating a first insulating layer and a first copper on a base copper foil;
(b) etching the first copper foil to form a portion for manufacturing a heat radiation via and a portion for fabricating the conductive via to form an opening, wherein the heat radiation via is formed by arraying a plurality of the conductive via in a form of an array, Forming a heat dissipation via pad;
(c) laser drilling the first insulating layer exposed by the opening to form a heat radiation via and a conductive via;
(d) forming a plating mask exposing the conductive via region and the heat radiation via region and performing copper plating to fill the via fill; And
(e) forming a circuit by peeling off the plating mask and etching the exposed first copper by flash etching
Wherein the heat dissipation via hole is formed in the printed circuit board. 6. The method of claim 5, wherein the base copper foil of step (a) is a copper foil on the surface of the decoratable core.

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