KR20100111144A

KR20100111144A - Method for manufacturing multi layer printed circuit board

Info

Publication number: KR20100111144A
Application number: KR1020090029554A
Authority: KR
Inventors: 안복만
Original assignee: 안복만
Priority date: 2009-04-06
Filing date: 2009-04-06
Publication date: 2010-10-14

Abstract

The present invention relates to a method for manufacturing a multilayer printed circuit board, and in particular, the present invention is modified by the method of manufacturing a multilayer printed circuit board in which a double-sided copper foil laminate, a thermally conductive insulating member, and a metal base are laminated by heating and pressing. The present invention relates to a method for manufacturing a multilayer printed circuit board, which can prevent defects in a circuit pattern formed on the top surface of a double-sided copper foil laminate due to a difference in coefficient of thermal expansion during heating and pressing of the elements. The present invention forms a circuit pattern on the bottom surface of the double-sided copper foil laminate, heats and pressurizes the metal base on the bottom surface of the double-sided copper foil laminate having the above-described circuit pattern through a thermally conductive insulating material, and then circuit pattern on the top surface of the double-sided copper foil laminate. Since the circuit pattern on the top surface of the copper foil laminate is formed after the heat press operation, the copper circuit laminate on the top surface shrinks or expands during heating and pressurization, thereby preventing defects in the circuit pattern on the top surface. It can greatly reduce.

Description

Manufacturing method of multilayer printed circuit board {METHOD FOR MANUFACTURING MULTI LAYER PRINTED CIRCUIT BOARD}

The present invention relates to a method for manufacturing a multilayer printed circuit board, and more particularly, to a multilayer printed circuit board by vacuum heating and pressing a double-sided copper foil laminate on which a component is mounted and a metal base for releasing heat generated from the double-sided copper foil laminate to the outside. The present invention relates to a method for manufacturing a multilayer printed circuit board.

A printed circuit board is a component in which circuits, which are the basis of all electronic products, are assembled. As a function of electronic products is developed, a printed circuit board is also required to have a high performance product having multilayer high density and multifunction.

As a result, multi-layer high-density circuits are simultaneously driven, and module development products such as TVs, automobiles, computers, and multi-lights are exploding.

Due to these specificities, demand for special parts is rapidly increasing, and in particular, the heat generation problem of printed circuit boards is intensifying day by day, and effective heat dissipation measures are recognized as an urgent task. Overcoming these problems is a measure that determines the reliability of products.

Therefore, in recent years, when a multilayer printed circuit board is manufactured, a circuit pattern is formed on both sides of a copper foil laminate, and thermal conductivity of an aluminum plate is attached by a vacuum heating press method to quickly release heat generated in the circuit to the outside.

However, since the double-sided copper foil laminate expands or contracts due to the difference in coefficient of thermal expansion of each component during vacuum heating and pressing of the double-sided copper foil laminate and the aluminum plate, the position of the through hole formed for heat dissipation in the double-sided copper foil laminate may be shifted. . Due to this cause, a defect may occur in the circuit pattern formed on the top surface of the double-sided copper foil laminate, which may cause a defect of the multilayer printed circuit board.

One aspect of the present invention provides a method of manufacturing a multilayer printed circuit board that can prevent a defect of a circuit pattern formed on the upper surface of a double-sided copper foil laminate by changing the manufacturing process of the multilayer printed circuit board.

In the method of manufacturing a multilayer printed circuit board according to an exemplary embodiment of the present invention, a circuit pattern is formed on a lower surface of a copper foil laminated plate on which a plurality of through holes are formed, and a metal base is laminated on a lower surface on which the circuit pattern is formed via a thermal conductive insulating material. And heating and pressing, and forming a circuit pattern on the upper surface of the copper foil laminate after the heating and pressing.

The copper foil laminate includes a base on which both sides of the copper foil are formed, and the base includes a material having a coefficient of thermal expansion substantially the same as the coefficient of thermal expansion of the thermally conductive insulating material.

The base and the thermally conductive insulating material include an electrically insulated thermally conductive prepreg.

According to another aspect of the present invention, there is provided a method of manufacturing a multilayer printed circuit board, preparing a copper foil laminate having copper foils formed on both surfaces thereof, forming a plurality of through holes in the copper foil laminate, and copper plating the inner walls of the plurality of through holes. A circuit pattern is formed on the bottom surface of the copper foil laminate, an aluminum plate is laminated on the bottom surface of the copper foil laminate via a thermally conductive insulating member, a thermally conductive prepreg is filled in the plurality of through holes, and the laminated after the filling. And heating and pressing the copper foil laminate, the thermal conductive insulating member, and the aluminum plate, and forming a circuit pattern on the upper surface of the copper foil laminate after the heat press.

According to an embodiment of the present invention described above, the present invention provides a circuit pattern on the bottom surface vacuum-pressurized to the metal base for heat dissipation of both sides of the double-sided copper foil laminated plate formed with a plurality of through holes in the manufacture of a multilayer printed circuit board It is formed before the vacuum heating pressurization, and the circuit pattern is formed on the top face after the vacuum heating pressurization, so that the circuit pattern work on the top face of the double-sided copper foil laminate is performed after the vacuum heat pressurization operation. The defect of the circuit pattern of the surface can be prevented beforehand, and the product defect can be greatly reduced.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a flowchart illustrating a manufacturing method of a multilayer printed circuit board according to an exemplary embodiment of the present invention.

As shown in FIG. 1, in the method of manufacturing a multilayer printed circuit board according to an exemplary embodiment of the present invention, a process of preparing a copper foil laminate having copper foils formed on both surfaces thereof (100) and a process of forming a through hole through the copper foil laminate (110) ), A process of copper plating the inner wall of the through hole and the surface of the copper foil laminate (120), a process of forming a circuit pattern on the bottom surface (bottom surface) of the copper foil laminate (130), and a thermally conductive insulating material on the bottom surface of the copper foil laminate having the circuit pattern Lay-up (laminate up) the metal base through the process (140), filling the thermal conductive prepreg in the through hole (150), heat pressurizing the laminated stack (160), after heat press Process of forming a circuit pattern on the upper surface (top surface) of the copper foil laminate (170), Photo Solder Resist (PSR) process (180) of applying a solder resist of an epoxy component to the circuit pattern formed on the upper surface of the copper foil laminate PSR After the information includes the step 190 for processing the outer shape is cut to the final outer shape.

Hereinafter, the manufacturing process of the multilayer printed circuit board will be described in detail with reference to FIGS. 2A to 2H.

2A to 2H are schematic diagrams sequentially illustrating a method of manufacturing a multilayer printed circuit board according to an exemplary embodiment of the present invention.

As shown in FIG. 2A, copper clad laminates (CCL; Copper Clad Laminate) 1 have copper foils 21 and 22 laminated on both sides of the base 10. The copper foil laminated sheet 1 means the thin laminated sheet coated with copper (Cu). As a material of the base 10 of the copper foil laminated sheet 1, an electrically insulated heat conductive prepreg (T-preg) is used. In addition to the material of the base 1 of the copper-clad laminate 1 may be used a thermosetting resin that is commonly used as a base material. Thermosetting resins have excellent insulation properties but have insufficient mechanical strength and have a coefficient of thermal expansion (CTE) greater than that of metals. Therefore, resins having glass fiber, glass nonwoven fabric, or other reinforcing materials may be used.

As illustrated in FIG. 2B, a through hole 40 may be formed in the copper foil laminate 1. A well-known method, such as drilling and punching, is used for the method of forming the through hole 40 in the copper foil laminated board 1. For example, a drilling method may include a carbon dioxide laser, an ultra violet (UV) -based excimer laser, a UV-YAG laser, or the like.

As illustrated in FIG. 2C, after forming the through hole 40 in the copper foil laminate 1, the entire copper foil including both sides including the inside of the hole is electrolessly or electroplated 30. At this time, only the surface inside the hole may be copper plated 30. At this time, the inner wall of the through hole 40 is copper plated 30 and then surface treatment necessary for filling the through hole 40 to be described later is performed.

As shown in FIG. 2D, after the copper plating 30 is formed in the through hole 40 formed in the copper foil laminated plate 1, the dry film D / F is laminated on the copper foil layer on the bottom surface of the copper foil laminated plate 1, and the exposure, Conventional surface treatment including development and etching is carried out to form a circuit pattern on the lower surface of the copper foil laminate (1).

As shown in FIG. 2E, the circuit pattern 51 is formed on the bottom surface of the copper foil laminated plate 1, and then a metal is formed on the bottom surface of the copper foil laminated plate 1 on which the circuit pattern 51 is formed via a thermally conductive insulating material 60. The base 70 is laminated. At this time, in order to facilitate the lamination process, surface roughness may be formed on the copper foil laminate 1 to improve surface adhesion. In the surface treatment step, the lower surface of the copper foil laminated plate 1 is oxidized to reinforce the surface roughness, whereby the surface becomes rough and the lamination becomes easier. The same surface treatment process is performed also on the adhesive surface (upper surface) of the metal base 70. This metal base 70 quickly discharges heat generated from the surface of the copper foil laminated plate 1 to the outside. The metal base 70 is an aluminum plate, for example. In addition, the metal base 70 may be a copper plate or a stainless plate having high corrosion resistance.

As illustrated in FIG. 2F, the metal base 70 is laminated on the bottom surface of the copper foil laminate plate 1 on which the circuit pattern 51 is formed via the thermally conductive insulating material 60, and then thermoelectric is formed in the inner space of the through hole 40. The stacks 1, 60, 70 are heated and pressurized while filling the conductive prepreg 80. At this time, the thermal conductive prepreg 80 may be directly injected using a suitable tool in filling the thermally conductive prepreg 80 into the through hole 40, but the copper foil laminate ( Heat and pressure may be applied to the thermally conductive insulating material 60 between 1) and the metal base 70 to fill the through-hole 40, which is an empty space. By filling the thermally conductive prepreg 80 in the inner space of the through hole 40, heat generated in the component mounted on the copper foil laminate 1 can be quickly transferred to the metal base 70.

As shown in FIG. 2G, a portion of the thermally conductive prepreg that is cured in the process of heat pressing the laminate of the copper clad laminate 1, the thermally conductive insulating material 60, and the metal base 70 and protrudes over the surface is pressed. Remove and treat it flat. This is to flatten the protruding thermally conductive prepreg portion in the semi-cured state.

As shown in FIG. 2H, after the flat treatment, the dry film (D / F) is laminated on the copper foil layer on the upper surface of the copper foil laminate plate 1 and subjected to conventional surface treatment including exposure, development and etching. The circuit pattern 52 is formed on the upper surface of the laminated board 1.

Then, the solder resist insulating ink of an epoxy component is applied to the circuit pattern 52 formed on the upper surface of the copper-clad laminate through the PSR process, and after the PSR process, the final outer shape is cut out to manufacture a multilayer printed circuit board. .

[Description of the Reference Numerals]

1: copper foil laminated sheet 10: base

21,22: copper foil 30: copper plating

40: Through Hole 51,52: Circuit Pattern

60: thermal conductive material 70: metal base

80: thermal conductive prepreg

Claims

A circuit pattern is formed on the lower surface of the copper foil laminated plate on which a plurality of through holes are formed,

Laminating a metal base on the lower surface on which the circuit pattern is formed via a thermally conductive insulating material and then heating and pressing

And forming a circuit pattern on the upper surface of the copper foil laminated plate after the heating and pressing.

The method of claim 1,

The copper foil laminate includes a base on which the copper foil is formed on both sides,

And wherein the base is made of a material having a coefficient of thermal expansion that is approximately equal to that of the thermally conductive insulating material.

The method of claim 2,

And the base and the thermally conductive insulating material are electrically insulated thermally conductive prepregs.

Prepare the copper foil laminated board in which copper foil was formed in both surfaces,

Forming a plurality of through holes in the copper foil laminate;

Copper plating on the inner wall of the plurality of through holes,

Forming a circuit pattern on the lower surface of the copper foil laminate,

Aluminum plates are laminated on the lower surface of the copper foil laminated plate via a thermally conductive insulating member,

Filling the plurality of through holes with a thermally conductive prepreg,

Heating and pressurizing the laminated copper foil laminate, the thermally conductive insulating member, and the aluminum plate after the charging;