KR20060027676A - Method for fabricating the multi layer using layup process - Google Patents

Abstract

The present invention relates to a method for manufacturing a multilayer printed circuit board using a batch lamination method, comprising: providing an unclad member coated with a protective film through an adhesive member; Performing via a drilling process on the unclad member to form a via hole; Filling the liquid conductive paste into the via hole by immersing the unclad member in a chamber filled with a liquid conductive paste; Drying the unclad member to dry the liquid conductive paste filled in the via hole; Removing the protective film coated on the unclad member to form an insulating layer having a non-hole filled with a conductive paste; Manufacturing a core layer in which a predetermined circuit pattern is formed; And performing a batch lamination by a predetermined pressing process after matching the core layer on the insulating layer.

Multilayer printed circuit board, circuit layer, insulation layer, conductive paste, batch lamination

Description

Manufacturing method of multilayer printed circuit board using batch lamination method {Method for fabricating the multi layer using Layup Process}             

1 is a cross-sectional view of a multilayer printed circuit board formed by a conventional build-up method.

Figure 2 is a process of filling the paste in the conventional screen printing method to fill the via hole.

3 is a process chart for manufacturing an insulating layer constituting a multilayer printed circuit board according to the present invention.

4 is a view illustrating a process of filling a liquid conductive paste in a via hole formed in an unclad member according to the present invention.

5 is a process chart for manufacturing a core layer constituting a multilayer printed circuit board according to the present invention.

6 is a view illustrating a structure in which a plurality of insulating layers and a core layer are matched and aligned according to the present invention.

7 is a view showing a structure of a multilayer printed circuit board having a structure in which a plurality of insulating layers and a core layer are collectively stacked by a predetermined pressing process according to the present invention.

* Explanation of simple symbols in the drawings

100: unclad member 101: insulating material

102: adhesive member 103: protective film

104: via hole 105: liquid conductive paste

110: insulation layer 200: copper foil laminated disc

 201: insulating layer 202: copper foil

203: via hole 204: plating layer

205: resist pattern 210: core layer

The present invention relates to a method for manufacturing a multilayer printed circuit board using a batch lamination method.

More specifically, unfilling the insulating layer and the core layer formed by immersing the unclad member in which the via hole is formed in the chamber filled with the liquid conductive paste by a pressing process can prevent the unfilling of the conductive paste into the via hole. The present invention relates to a method for manufacturing a multilayer printed circuit board.

Printed Circuit Board (PCB) is made by attaching a thin plate such as copper to one side of phenolic resin insulation board or epoxy resin insulation board, and then etching it according to the wiring pattern of the circuit. It constructs the necessary circuits and makes holes by attaching and mounting the parts.

That is, the printed circuit board electrically connects the components mounted through the wiring pattern, supplies power and the like, and mechanically fixes the components.

The printed circuit board includes a single-sided PCB in which wiring is formed only on one side of the insulated substrate, a double-sided PCB in which wiring is formed on both sides, and an MLB (Multi Layered Board) that is wired in multiple layers. In the past, single-sided PCBs were used because of simple components and simple circuit patterns. However, in recent years, due to increased complexity of circuits and increased demand for high-density and miniaturized circuits, it is common to use double-sided PCBs or MLBs. The present invention relates to a process for producing MLB among them.

MLB has a great advantage that it can significantly increase the wiring density, but there is a difficulty that the manufacturing process is complicated. In particular, since the inner layer is not deformable when the process is completed according to the conventional build-up method, if there is an error in the inner layer, all the finished products become defective. Many inspection devices have been developed and used to prevent such errors in advance.

Hereinafter, a configuration of a multilayer printed circuit board implemented by a conventional build-up method will be described in detail with reference to FIG. 1.

The build-up method is literally a method of manufacturing a method of forming an inner layer first, and then additionally stacking outer layers one by one. More specifically, an insulating layer is laminated on a base substrate on which a predetermined inner layer circuit pattern is formed. A method of stacking a plurality of outer layers by performing an additional masking process.

That is, in the method of manufacturing a package substrate using the build-up method, the plating layer 13 is formed on the copper-clad laminate 11 having the via holes 12 formed by drilling, and the inner layer circuit pattern is formed by performing a predetermined masking process. The formed base substrate is produced.

Thereafter, the insulating layer 14 is stacked on the base substrate, and then laser processing is performed to form blind via holes for performing interlayer electrical connection, and to form a seed layer 16 for forming an outer circuit pattern.

After the seed layer 16 is formed as described above, a predetermined masking process is performed to form a resist pattern and copper plating is performed to complete the outer circuit pattern 17.

Thereafter, the multilayer printed circuit board is finally formed by applying an PSR ink 18 (Photo Imageable Solder Resist Mask ink) that forms an outer layer by removing a resist pattern and etching an unnecessary seed layer and prevents solder bridging. Complete

Existing methods of manufacturing printed circuit boards have limitations in order to cope with the recent trend of thin and short and short, and manufacturing costs are also rapidly increasing as they are multilayered in response to high functionality of PCBs. However, the selling price of electronic components for products is falling relatively, and the development period is required to be shortened with rapid development.

As described above, as described above, a method of manufacturing via holes by laser according to the existing build-up method, and plating the inner wall to connect the layers and sequentially stacking them, there are many problems in minimizing the process cost. There was also a limit to shortening the production period.

In order to secure this, a manufacturing method has been developed in which a circuit layer and an insulating layer are each manufactured through independent processes, and then a plurality of batches are stacked in parallel.

However, as shown in FIG. 2, the via hole 21 which performs interlayer electrical conduction in manufacturing the insulating layer is provided with a printing screen printing method in which a printing network 22 is installed on a substrate 20 and a liquid conductive paste is applied. As a result of filling the paste, residues such as air bubbles remain in the via hole 21, and thereafter, a problem that has a fatal adverse effect on reliability due to failure of via hole destruction and signal disconnection due to heat occurs.

In addition, in the screen printing method, since the same printing network 22 as the via hole 21 pattern is manufactured to be separate, it is difficult to produce the printing network 22 in the case of fine holes, and a problem in which fine holes are not easily embedded.

In order to solve the above problems, the present invention provides a conductive layer for via holes by laminating an insulating layer and a core layer formed by immersing an unclad member in which a via hole is formed in a chamber filled with a liquid conductive paste. It is to provide a method for manufacturing a printed circuit board that can prevent the filling of the paste.

Method of manufacturing a printed circuit board using a batch lamination method according to the present invention for achieving this object comprises the steps of providing an unclad member coated with a protective film through an adhesive member; Performing via a drilling process on the unclad member to form a via hole; Filling the liquid conductive paste into the via hole by immersing the unclad member in a chamber filled with a liquid conductive paste; Drying the unclad member to dry the liquid conductive paste filled in the via hole; Removing the protective film coated on the unclad member to form an insulating layer having a non-hole filled with a conductive paste; Manufacturing a core layer in which a predetermined circuit pattern is formed; And performing a batch lamination by a predetermined pressing process after matching the core layer on the insulating layer.

Hereinafter, a method of manufacturing a parallel multilayer printed circuit board according to the present invention will be described in detail with reference to the accompanying drawings.

First, referring to FIG. 3, a method of manufacturing an insulating layer having a via hole filled with a liquid conductive paste according to the present invention will be described in detail.

As shown in FIG. 3A, an unclad material 100 having a protective film 103 coated thereon is provided on an insulating material 101 via an adhesive film 102.

In general, a semi-cured adhesive member 102 is formed on both sides on an insulating material 101 formed of a synthetic material of a resin and a reinforcing base material, and a protective film 103 for protecting the adhesive member 102 is an adhesive member. It is thinly coated on 102.

Here, the adhesive member 102 is made into a semi-cured state by infiltrating the thermosetting resin into the glass fiber, and is used as a raw material to be bonded when collectively laminating with the core layer described later. The film is cured by pressing or heating a predetermined amount or more to bond the insulating layer and the core layer.

In addition, the protective film 103 is formed of a polyethylene terephthalate (PET) material, and serves to prevent damage to the adhesive member 102 and foreign matter intrusion, which may occur during the manufacturing process of the insulating layer 100.

After providing the unclad member 100 configured as described above, as shown in FIG. 3B, a via hole 104 for interlayer electrical connection is formed in the unclad member.

Here, the via hole 104 is formed by drilling, and performs various processes of deburring and desmear to remove various contaminants and foreign substances generated during drilling.

As described above, after the via hole 104 is formed to perform the interlayer electrical connection to the unclad member, as shown in FIG. 3C, the liquid conductive paste 105 is filled in the via hole.

Here, the liquid conductive paste 105 filled in the via hole 104 is a conductive material in which a main component is a metal, such as Cu, Ag, Au, Sn, Pb, alone or in an alloy form, mixed with an organic adhesive.

In this case, in the method of filling the via hole 104 with the liquid conductive paste, as shown in FIG. 4, the unclad material 100 having the via hole 104 is immersed in a chamber in which the conductive paste in the liquid state is contained.

Thereafter, the liquid conductive paste in the chamber flows in one side direction of the unclad member 100 by using a pressure injection method using a nozzle or the like, so that the liquid conductive paste can be easily filled in the via hole 104. Make sure

As described above, after filling the liquid conductive paste into the via hole, as shown in FIG. 3D, the conductive paste 104 filled in the via hole 104 is cured through a drying process, and the insulating material 101 is formed on the insulating material 101. By removing the protective film 103 attached through the adhesive member 102, the insulating layer 110 in which the via hole 104 filled with the conductive paste is formed is completed.

As described above, after the insulating layer for interlayer insulation of the printed circuit board is formed, a core layer which is collectively laminated on the insulating layer is manufactured by a predetermined pressing process as shown in FIG. 5.

A method of manufacturing the core layer constituting the printed circuit board according to the present invention will be described in detail with reference to FIG. 5.

First, as shown in FIG. 5A, a copper clad laminate (CCL; Copper Clad Laminate) 200 having a thin copper foil 202 formed on both surfaces thereof is provided through an insulating layer 201.

Here, the copper-clad laminate 200 is a disk made of a printed circuit board generally has a structure in which a thin copper 202 is coated on the insulating layer 201.

At this time, there are many kinds of copper clad laminate, such as glass / epoxy copper clad laminate, heat resistant resin copper clad laminate, paper / phenol copper clad laminate, high frequency copper clad laminate, flexible copper clad laminate (polyimide film), and composite copper clad laminate. Glass / epoxy copper clad laminates are mainly used for double-sided and multi-layer PCB fabrication. In addition, although the thickness of copper foil is about 18-70 micrometers normally, 5 micrometers, 7 micrometers, and 15 micrometers may be used according to the refinement | miniaturization of a wiring pattern.

After providing the copper clad laminate as described above, as shown in FIG. 5B, a via hole 203 is formed in the copper clad laminate 200 to perform interlayer electrical connection.

The via hole 203 is formed by drilling, and performs deburring and desmear processes to remove various contaminants and foreign substances generated during drilling.

Here, the via hole 203 may use mechanical drilling, but it is preferable to use YAG (Yttrium Aluminum Garnet) laser or CO ₂ laser because it requires precise processing when forming a fine circuit pattern.

After forming the via holes 203 for the interlayer connection as described above, as shown in FIG. 5C, the electroless copper plating and the electrolytic copper plating are performed on the copper foil layer 202 and the via holes 203 to form the plating layer 204. To form.

In this case, when the via hole 203 is a fine hole, the plating layer 204 is formed and the inside area of the via hole 203 is subjected to fill plating. However, the method may further include filling the paste after the plating layer 204.

Here, electroless copper plating is performed first and then electrolytic copper plating is performed because electrolytic copper plating that requires electricity cannot be performed on the insulating layer.

That is, in order to form the electroconductive film required for electrolytic copper plating, electroless copper plating is thinly performed as the pretreatment. Electroless copper plating is difficult to process and economically disadvantageous, so the conductive portion of the circuit pattern is preferably formed of electrolytic copper plating.

After forming the plating layer as described above, as shown in FIG. 5D, an etching resist pattern 205 for forming a circuit pattern is formed on the copper plating layer 204.

Here, in order to form the etching resist pattern 205, the circuit pattern printed on the artwork film must be transferred onto the substrate. There are various methods of transferring, but the most commonly used method is a method of transferring a circuit pattern printed on an artwork film by ultraviolet light to a dry film using a photosensitive dry film.

At this time, the dry film to which the circuit pattern is transferred serves as an etching resist, and when performing the etching process using the dry film as an etching resist, as shown in Figure 5e, the etching resist pattern 205 is formed The plating layer 204 in the unoccupied region is removed to form a predetermined circuit pattern.

After the predetermined circuit pattern is formed as described above, the remaining dry film is peeled off as shown in FIG. 5F, and then the AOI inspection and blackening process are performed to complete the core layer 210.

Here, inspection using AOI prevents defects generated during the circuit layer process. In addition, the blackening treatment that gives the roughness by oxidizing the surface of the copper foil by a chemical method enhances the adhesion and heat resistance of the circuit layer before the circuit layer 210 is adhered to the insulating layer 110.

As described above, after the core layer having the predetermined circuit pattern is formed, as shown in FIG. 6, the insulating layer 110 having the via layer 104 filled with the conductive paste and the core having the predetermined circuit pattern are formed as shown in FIG. 6. Layers 210 are stacked in a batch.

In this case, the via hole 104 filled with the conductive paste formed in the insulating layer 110 and the via hole 104 formed in the core layer 210 are accurately matched to be electrically connected to each other.

After stacking the plurality of insulating layers 110 and the core layer 210 as described above, as shown in Figure 7, the final multi-layer printing by pressing and heating for a predetermined time by a predetermined pressing process Manufacture a circuit board.

As described above, according to the method for manufacturing a parallel multilayer printed circuit board according to the present invention, by forming an insulating layer of a printed circuit board by immersing an unclad member having a via hole in a chamber filled with a liquid conductive paste, It provides an effect of greatly increasing reliability by eliminating fatal defects such as via hole destruction and signal disconnection caused by bubbles and the like.

In addition, the present invention is to fabricate the insulating layer of the printed circuit board by immersing the unclad member formed with the via hole in the chamber filled with the conductive paste instead of the conventional screen printing method for manufacturing and using the same screen as the via hole pattern. Easy and any microhole filling provides a possible effect.

Herein, the present invention described above has been described with reference to preferred embodiments, but those skilled in the art can variously modify the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. It will be appreciated that this can be changed.

Claims (6)

Providing an unclad member coated with a protective film through an adhesive member; Performing via a drilling process on the unclad member to form a via hole; Filling the liquid conductive paste into the via hole by immersing the unclad member in a chamber filled with a liquid conductive paste; Drying the unclad member to dry the liquid conductive paste filled in the via hole; Removing the protective film coated on the unclad member to form an insulating layer having a non-hole filled with a conductive paste; Manufacturing a core layer in which a predetermined circuit pattern is formed; And Performing a batch lamination by a predetermined pressing process after matching the core layer on the insulating layer; Method of manufacturing a printed circuit board using a batch lamination method comprising a. The method of claim 1, The adhesive member is a manufacturing method of a printed circuit board using a batch lamination method, characterized in that the semi-hardened epoxy resin. The method of claim 1, The protective film is a manufacturing method of a printed circuit board using a batch lamination method, characterized in that the polyethylene terephthalate (PET). The method of claim 1, The unclad member is a method of manufacturing a printed circuit board using a batch lamination method, characterized in that the curable epoxy resin.  The method of claim 1, Filling the liquid conductive paste into the via hole may include: A method of manufacturing a printed circuit board using a batch lamination method, characterized in that the liquid conductive paste is carried out by pressure injection in the lateral direction of the unclad member. The method of claim 1, wherein the manufacturing of the core layer comprises: Drilling through the copper-clad laminate to form via holes for interlayer connection; Forming a plating layer by performing electroless and electrolytic copper plating on the copper foil laminated disc on which the via holes are formed; Coating a dry film cured by ultraviolet rays on the plating layer; Matching artwork fill with a predetermined circuit pattern formed on the dry film; Performing a curing treatment on the dry film by performing ultraviolet irradiation through the artwork film; Etching the opened plating layer by removing the dry film uncured by the ultraviolet irradiation; And Removing a dry film coated on the non-etched plating layer to form a predetermined circuit pattern Method of manufacturing a parallel printed circuit board comprising a.

Images