KR100441253B1 - method for manufacturing multi-layer printed circuit board using bump - Google Patents

Abstract

A bump that simplifies the process of manufacturing a multilayer printed circuit board by not forming a via hole by using a laser drill using a method of forming a bump (80 μm) by plating and heating and pressurizing and laminating it collectively. Disclosed is a method of manufacturing a multilayer printed circuit board. According to the present invention, the CCL having the copper foil on both sides of the resin layer is processed through via holes, and a circuit is formed on the copper foils on both sides of the CCL by etching and electroless plating to conduct the entire copper foil on both sides. Stacking dry films on both sides of the CCL on which the circuit is formed, and then forming bumps by electrolytic copper plating and Sn / Pb plating to manufacture an inner layer; CCL with copper foil on both sides of the resin layer is machined through a CNC drill, and the panel is plated on the hole, and a circuit is formed on one copper foil surface of the CCL facing the inner layer during lamination to form an outer layer. Doing; And inserting the processed prepreg into a position where bumps are formed between the formed inner layer and the outer layer, and laminating by heating and pressing.

Description

Method for manufacturing multi-layer printed circuit board using bump}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer printed circuit board using bumps. In particular, a bump (80 μm) is formed by plating and then heated and pressed to collectively stack the via holes using a laser drill. The present invention relates to a method for manufacturing a multilayer printed circuit board using bumps, which simplify the process of manufacturing the multilayer printed circuit board by not processing the same).

In general, a printed circuit board is wired to one side or both sides of a board made of various thermosetting synthetic resins, and then ICs and electronic components are disposed and fixed on the boards, and electrical wiring therebetween is coated with an insulator. Background Art Since the development of electronic components, multilayer printed circuit boards made of overlapping circuit conductors have been developed, and recently, research on high density of multilayer printed circuit boards has been actively conducted.

A multilayer printed circuit board is a method of forming a multilayer circuit by sequentially stacking an insulating layer and a circuit conductor. The multilayer printed circuit board not only enables the formation of microscopic via holes connecting the interlayer circuits, but also enables the formation of high density circuits because the circuit thickness is thin and the formation of fine circuits is easy.

In recent years, miniaturization, thinning, weight reduction, and high functionalization of mobile communication devices such as mobile phones, PDAs, and various electronic devices such as computers and camcorders are progressing. In addition to the miniaturization and thinning of various electronic components constituting electronic devices, these electronic parts Various technologies have been actively developed to enable high-density packaging of printed circuit boards.

In a conventional multilayer printed circuit board manufacturing process, an interlayer blind via hole is formed using a laser drill, and the via hole is formed to have interlayer conduction through plating. In addition, when a via hole is formed through three conductive layers, a stack via must be formed through repetitive work. In order to mount a part on the surface of the via hole, the hole is filled with resin. The plated top of the filled resin must then be replated.

That is, the conventional multilayer printed circuit board has formed via holes using a laser drill, and has made interlayer conduction through plating of the via holes. Multilayer printed circuit board is manufactured by adopting two methods, laser drill and plating.

Therefore, conventional multi-layer printed circuit board manufacturing requires expensive laser drilling equipment and a place to install the same. As the number of via holes increases, there is a restriction in money and place. In the case of blind via holes, a small diameter and a penetration Due to the unstructured structure, it was difficult to circulate the plating solution, causing problems in plating reliability.In the case of stack vias, the process is increased due to repetitive work, and interlayer conduction due to poor registration is problematic. The process of filling the hole with resin is difficult to mount the parts on the part, and the plating is required after the hole filling, and even when plating, there is a problem in that the height is different from the surroundings due to the plating deviation.

The present invention was invented to solve the above problems, and after forming a conductive bump (hereinafter referred to as bump) having a height of 80 µm by plating, heating, pressing, and laminating them collectively, a six-layer multilayer printed circuit board In manufacturing, a circuit is formed on both copper foil surfaces of a CCL (Copper Clad Laminate), and then laminated on a copper foil surface having both circuits using dry film (D / F) or other material which may be a plating resist. After lamination, bumps (80 µm) are formed by plating, and the outer layers are processed and laminated, thereby eliminating the need to process via holes using a laser drill, thereby manufacturing a multilayer printed circuit board. An object of the present invention is to provide a method of manufacturing a multilayer printed circuit board using bumps to simplify the process.

1 and 2 are process charts showing a manufacturing process of a six-layer printed circuit board using bumps according to the present invention.

3 and 4 are process charts showing a manufacturing process of an eight-layer printed circuit board using bumps according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10, 70: CCL 11, 72: resin layer

12, 71: copper foil surface 20: via hole

30, 50: dry film 40, 74, 90: circuit

60: bump 80, 81: hole

82: prepreg 100: inner layer

200: outer layer

The present invention for achieving such an object,

Via holes are processed in the CCL having copper foil on both sides based on the resin layer, and the CCL is formed on both copper foil surfaces by etching to form a circuit and electroless plated to conduct the entire copper foil surface on both sides. Forming a bump by electrolytic copper plating and Sn / Pb plating after laminating dry films on both sides of the CCL on which the CCL is formed;

CCL with copper foil on both sides of the resin layer is machined through a CNC drill, and the panel is plated on the hole, and a circuit is formed on one copper foil surface of the CCL facing the inner layer during lamination to form an outer layer. Doing;

And inserting the processed prepreg into a position where bumps are formed between the formed inner layer and the outer layer, and laminating by heating and pressing.

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

1 and 2 are cross-sectional views illustrating a manufacturing process of a six-layer printed circuit board using bumps according to the present invention, and FIGS. 3 and 4 are views illustrating a manufacturing of an eight-layer printed circuit board using bumps according to the present invention. A cross section to show the process.

A method of manufacturing a six-layer printed circuit board using bumps according to the present invention will be described. As shown in FIGS. 1 and 2, the inner layer 100 of the six-layer printed circuit board may be formed to form a core material (Core). The CCL (Copper Clad Laminate) 10 having the copper foil surface 12 formed on both sides of the ground layer 11 is machined using a CNC drill, and the CCL 10 in which the holes 20 are processed. Apply dry film (D / F) to both sides of the film, expose and develop the dry film (D / F) 30, and peel it off by etching to form circuits 40 on both sides of the CCL 10. do. (steps a-d)

Thereafter, electroless plating is performed on the CCL 10 having the circuit 40 formed thereon so as to conduct the entire copper foil surface of the CCL 10, and then dry film (D / F) 50 on both sides of the CCL 10. After coating, after forming a bump (60) of 80㎛ height by electrolytic copper plating and Sn / Pb plating, and after the bump 60 is formed, the dry film (D / F) 50 is peeled off , Soft etching is performed to distinguish between the circuit 40 and the circuit 40, between the circuit 40 and the bump 60, and between the bump 60 and the bump 60. (step e-i)

Here, the dry film laminated at the step of forming the bumps may be replaced by laminating other materials such as an ink forming a plating resist.

In addition, the outer layer 200 of the six-layer printed circuit board is processed through the hole 80 by using a CNC drill, CCL (70) formed with copper foil surface 71 on both sides with respect to the resin layer 72, After the panel plating 73 having a thickness of 25 μm is performed on the old hole 80, a circuit 74 is formed on one side of the copper foil surface of the CCL 70 facing inward during lamination. (j-m steps)

When the inner layer 100 and the outer layer 200 of the multilayer printed circuit board are completed, the prepreg 82, which is a resin penetration processing material, is formed at the same position as the bump 60 is formed by using a mold or a drill. The prepreg 82 processed between the first and second layers of the outer layer 200 and the third and fourth layers of the inner layer 100 and the fifth and sixth layers of the outer layer 200 is processed. 6 layers of multilayer printed circuit boards are produced by forming a circuit 90 (or step) on both sides of the stacked layers after laminating by heating and pressing.

In addition, the manufacturing method of the multilayer printed circuit board of 8 or more layers according to the present invention is used in the outer layer in the same manner as the manufacturing method of the six-layer multilayer printed circuit board of FIGS. 1 and 2, as shown in FIGS. In order to make the core material (Core), the hole 20 is processed by using a CNC drill on the CCL 10 having the copper foil surface 12 formed on both sides with respect to the resin layer 11, and the Dry film (D / F) is laminated on both sides, and the dry film (D / F) 30 is exposed and developed, and it is peeled off by etching to form a circuit 40 on one side of the CCL 10. . (steps a-d)

Thereafter, after electroless plating is performed, dry films (D / F) 50 are laminated on both sides of the CCL 10, and then bumps having a height of 80 µm are formed by Sn / Pb plating, which is an electroplating process. 60 is formed, and when the bump 60 is formed, the dry film (D / F) 50 is peeled off, and then, between the circuit 40 and the circuit 40, between the circuit 40 and the bump 60. , Soft etching is performed to distinguish between the bump 60 and the bump 60. (step e-i)

In this way, a circuit is formed on one copper foil surface of the CCL 10, and bumps are formed by plating on the copper foil surface on which the circuit is formed, and thus the CCL 10 thus produced is made of six layers as shown in FIGS. After the circuit 90 is formed on one side of the printed circuit board 200, a prepreg 82 in which the holes 81 are processed is sandwiched and heated and pressed to be laminated, and then the circuits are formed on both sides of the printed circuit board 200. An eight-layer multilayer printed circuit board is manufactured by forming (or step) 90).

The multilayer printed circuit board according to the present invention manufactured by such a method is used in mobile communication devices such as mobile phones and PDAs, computers, camcorders, and the like, which are gradually miniaturized and lightened, and etching copper foil on both sides of CCL (Copper Clad Laminate). After that, bumps are formed using plating and stacked together to reduce costs and installation sites by not using a laser drill to form via holes in manufacturing a multilayer printed circuit board.

As described above, the manufacturing method of the multilayer printed circuit board according to the present invention, together with the miniaturization and thinning of various electronic components constituting the electronic device, also packs them with respect to the printed circuit board on which the electronic components are installed. Since it is necessary to make the bumps by plating, more parts can be mounted because the bumps are replaced to replace the via holes, and the cost is reduced because the via holes are not processed using a laser drill. In addition, since the core material of the two layers is laminated at a time, the labor of the work can be reduced, and the higher the number of layers, the cost can be reduced.

Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited thereto and may be improved or modified by those skilled in the art within the scope of the technical idea of the present invention.

Claims (4)

Iii) The via hole 20 is processed through the CCL 10 having the copper foil surface 12 on both sides with respect to the resin layer 11, and the circuit is formed by etching the CCL 10 on both copper foil surfaces. After forming and electroless plating to conduct the entire copper foil surface on both sides, the dry film 50 is laminated on both sides of the CCL (10) where the circuit is formed, and then bump 60 by electrolytic copper plating and Sn / Pb plating Forming an inner layer 100 to form a; Ii) The CCL 70 having copper foil surfaces 71 formed on both sides of the resin layer 72 is machined into a hole 80 using a CNC drill, and a panel plating 73 is performed on the hole 80. And forming an outer layer (200) by forming a circuit (74) on one side of the copper foil surface of the CCL (70) facing the inner layer (100) during lamination; Iii) a step of stacking the prepreg 82 having the holes 81 processed therein between the inner layer 100 and the outer layer 200 formed in the above step, where the bumps 60 are formed, and heating and pressing them. Method of manufacturing a multilayer printed circuit board using a bump comprising a. The CCL (10) according to claim 1, wherein the step (c) comprises forming a circuit on the copper foil surface on one side of the CCL 10 by etching and electroless plating to conduct the entire copper foil surface on one side, and then forming the circuit. And forming a bump (60) by Sn / Pb plating, which is an electroplating method, after laminating the dry film (50) on one side thereof. The method of claim 1 or 2, wherein the bumps are formed to have a height of 80 µm. 3. The bump printed circuit board of claim 1 or 2, wherein the lamination of the dry film in the step before forming the bump in the step (v) is replaced by laminating a material forming the plating resist. Manufacturing method.