KR20110096245A - Manufacturing process of printed circuit board - Google Patents

Abstract

PURPOSE: A printed circuit board manufacturing method is provided to plug an insulating resin to the inside of a penetration hole formed on a substrate using a hot press method, thereby improving insulating property at a device mounting position. CONSTITUTION: A substrate(32) comprised of metal with thermal conductance or nonferrous metals is prepared. A penetration hole(36) is formed using a press machine at each device mounting position on the substrate. An insulating resin(38) is filled in a penetration hole by pressing the substrate using a hot press machine(42). A part hole(44) for device insertion is formed in the central part of the penetration hole filled with the insulating resin. A light-sensitive dry film(46) for forming a circuit pattern on the surface of substrate is thermo-compressed using a hot roller(48).

Description

MANUFACTURING PROCESS OF PRINTED CIRCUIT BOARD

The present invention relates to a method for manufacturing a printed circuit board, and more particularly, a single-sided PCB, a double-sided PCB, or a multi-layered PCB using a metal or non-ferrous metal or hard substrate having thermal conductivity. In manufacturing a board printed circuit board, ink plugging by plugging an insulating resin into a hot press method using a hot press inside a through hole formed on a substrate for mounting various elements. (Ink plugging) method can improve the insulation characteristics at the device mounting portion, shorten the manufacturing process, significantly improve the productivity per unit time, and reduce production costs The present invention relates to a method of manufacturing a printed circuit board.

In general, a printed circuit board is a conductive pattern formed of a material having excellent electrical conductivity such as copper foil on an electrical insulator, and an active element including a power source such as a power supply and an amplifier on the conductive pattern. Active components), passive components such as resistors, capacitors, and coils, and acoustic or visual components, etc., respectively, perform their functions and are mechanical devices mounted in an interconnected state to support other components.

Such printed circuit boards are applied to washing machines, TVs, and refrigerators as well as system boards such as routers, servers, satellites, and automobiles, which are commonly found in home appliances. As the industrial fields related to information terminal devices such as communication devices, network equipment and display devices for information communication, etc. are expanded and developed, demand for printed circuit boards suitable for them is rapidly increasing.

As functions of various electronic products become more and more complicated and diverse as described above, their size is gradually being miniaturized and slimmed, so that a plurality of conductor patterns (circuits) are formed on a single insulating substrate so that the thickness is relatively small. There is a demand for double-sided printed circuit boards or multilayer printed circuit boards that can achieve high reliability by making thin, high-density and multi-functional, and enhancing adhesion between the copper foil constituting the conductor pattern and the insulating board.

Meanwhile, when various electronic products are driven, heat is generated from each device on a printed circuit board mounted on the electronic product. When the heat generated from various devices on the printed circuit board is not properly discharged to the outside, the device There is a problem that the life of the product is shortened because their function is reduced by heat.

Accordingly, in order to improve heat dissipation, a printed circuit board using a metal or nonferrous metal having thermal conductivity as a substrate has recently been proposed.

1 is a configuration diagram showing a main sequence of a method of manufacturing a printed circuit board to which an ink plugging method is applied.

Referring to this, in the manufacturing method 10 of the conventional printed circuit board, in order to apply the insulating material to the inner wall surface of the through-hole 14 formed by the Computer Numerical Control (CNC) method to the element or wire mounting position on the substrate 12. Ink plugging method is applied.

To this end, the substrate 12 having the through holes 14 formed thereon is mounted on the printer 16, and then a separate squeegee (Squeegee: 20) is covered with the silk net 18 on the upper surface of the substrate 12. The ink 22 is filled in the through hole 14 on the substrate 12 in such a manner as to move several times.

However, in the conventional method of manufacturing a printed circuit board to which the ink plugging method is applied, plugging the insulating ink into the through hole 14 on the substrate 12 is very cumbersome, and it is necessary to repeat the printing many times. There is a problem that the time required for the unit work process is very long.

Further, as shown in FIG. 1 in the state where the ink is filled in the inside of the through hole 14 on the substrate 12 as described above, while gradually raising the temperature of the ink filled in the through hole 14 in the oven dryer. The drying operation must be followed.

In addition, the portion that swells up the surface of the substrate 12 in the dried and filled state of the through hole 14 on the substrate 12 should be polished again using a belt polishing apparatus, and after the polishing process is completed. Since the work process to remove foreign matters generated during the polishing process has to be added, the number of processes is increased, and because each process takes a lot of time, productivity per unit time is relatively low, and production cost is increased. There is.

The present invention is to solve such a conventional problem, the object is to use a single-sided PCB, double-sided PCB or multi-layer PCB (Multi-Layer) using a metal (Metal) or non-ferrous metal or hard substrate having a thermal conductivity characteristics In manufacturing a board printed circuit board, ink plugging by plugging an insulating resin into a hot press method in a through hole formed on a substrate for mounting various elements. The present invention provides a method of manufacturing a new printed circuit board to improve insulation characteristics at an element mounting portion, compared to the conventional method in which the (Ink Plugging) method is applied.

Another object of the present invention is to shorten the manufacturing process of the printed circuit board, to significantly improve the productivity per unit time, and to provide a manufacturing method of a new printed circuit board to reduce the production cost.

In order to achieve the above object, the present invention has a relatively thick thickness, the through-hole forming step of forming a through hole for each mounting position of the element or wire on the substrate made of a thermally conductive metal or non-ferrous metal material cut to a predetermined size (ST1); Pressed through a hot press with a hot press in a state in which insulating resin and copper foil are sequentially disposed on the surface, the rear surface, or both the surface and the rear surface of the through hole formed on the substrate. An insulating resin plugging step (ST2) to fill the inside of the ball with an insulating resin (Resin); A non-filling cavity forming step (ST3) of forming a non-filling cavity in which the resin is not filled by using a press mold method with respect to the substrate to which the copper foil is bonded through the insulating resin; A part hole forming step (ST4) of forming a part hole for inserting an electronic device or a wire in the center of the through hole filled with the insulating resin; In order to remove burrs and foreign substances remaining in the soft copper foil when forming the component holes, and to increase the adhesion of the photosensitive dry film (D / F: Dry Film) to the surface of the copper foil. Washing the surfaces of the substrate and the copper foil with a brush to form the required surface roughness (ST5); A laminating step (ST6) of thermally compressing the photosensitive dry film for forming a circuit pattern on the surface of the substrate and the copper foil with a hot roller at 90 to 110 ° C; Photoresist is applied to the non-hardened portion on the substrate on which the photosensitive dry film for forming the circuit pattern is pressed, and then a necessary portion of the dry film on the substrate is passed through an exposure machine. A D / F exposure step (ST7) for irradiating and curing ultraviolet (UV) light; The photoresist-coated non-hardened portion was removed by dissolving the developer, and only the dry film corresponding to the hardened portion remained on the substrate to form a basic circuit pattern, except for the soldered portion corresponding to the surface edge of the part hole. A D / F development / corrosion / peeling step (ST8) which corrodes and removes unnecessary copper foil and peels off the dry film remaining on the surface of the soldering portion; PSR printing step (ST9) to apply a photo solder resist (PSR) ink on the surface of the substrate excluding the soldering portion so that the circuit pattern formed on the substrate and the surface of the substrate are not corroded or damaged by an external environment. Wow; A soldering step of performing a drying-exposure-developing-drying process on the substrate printed with the PSR ink, inserting a wire through a part hole, and soldering one end of the wire protruding outward with a soldering part. It comprises a (ST10).

In the insulating resin plugging step (ST2) of the present invention, the pressure is 20 to 25 kg / cm 2 and pressurized for 2 to 3 hours at a temperature of 170 to 180 ° C. with a hot press, and the insulating resin is plugged into the through hole on the substrate. It is characterized by.

In the D / F exposure step (ST7) of the present invention, the exposure amount of ultraviolet rays to the hardened portion of the dry film on the substrate is characterized in that 20 ~ 60mj / ㎠.

According to the present invention, in the process of filling the insulating resin into the through-holes formed in the substrate, the hot press method, rather than the conventional ink plugging method, is applied, which significantly reduces the number of processes and significantly shortens the working time. Therefore, there is an effect of greatly improving the productivity per unit time.

In addition, as described above, the production process is also reduced as the work process is reduced and the work time is greatly shortened.

In addition, in the present invention, since a separate insulating resin is formed evenly on the inner wall surface of the through hole corresponding to the circumferential surface of the part hole, there is an effect that the insulating property during use is improved.

1 is a configuration diagram showing a main sequence of a method of manufacturing a printed circuit board to which a conventional ink plugging method is applied.
2 is a flowchart illustrating a method of manufacturing a printed circuit board according to the present invention in stages.
3A and 3B are diagrams illustrating a method of manufacturing a printed circuit board according to the present invention.

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

2 to 3B, the method for manufacturing a printed circuit board 30 according to the present invention includes a through hole forming step ST1 for the substrate, an insulating resin plugging step ST2, and an unfilled hole forming step ST3. ), Part hole forming step (ST4), frontal step (ST5), laminating step (ST6), D / F exposure step (ST7), D / F development / corrosion / peeling It consists of a step ST8, a PSR printing step ST9 and a soldering step ST10.

In the through hole forming step ST1 of the present invention, a substrate 32 made of a thermally conductive metal or a nonferrous metal material having a relatively thick thickness and cut to a predetermined size is provided, and an element or a wire ( The through hole 36 is formed at each mounting position of the 34 using a press.

The substrate 32 is made of a metal or non-ferrous metal having thermal conductivity, such as copper or aluminum, in order to improve heat dissipation characteristics, the thickness of which is preferably 1.0 to 3.0 mm, the size of the design Depending on the size, it is cut to a size of 500mm (width) × 600mm (length).

In the insulating resin plugging step ST2, the insulating resin 38 and the copper foil 40 are formed on the surface, the rear surface, or both the front surface and the rear surface of the through hole 36 formed on the substrate 32. In order to sequentially press the pressure by the hot press 42 to the insulating resin 38 to be filled into the through hole 36.

The plugging operation of the insulating resin is performed by pressing for 2 to 3 hours at a pressure of 20 to 25 kg / cm 2 and a temperature of 170 to 180 ° C.

In the non-filled hole forming step ST3 and the part hole forming step ST4 of the present invention, the insulating resin 38 is mediated in the state where the insulating resin 38 is filled inside the through hole 36 on the substrate 32. A non-filled hole is formed in which the resin is not filled to the substrate 32 to which the copper foil 40 is adhered, using a press mold method, and at the center of the through hole 36 filled with the insulating resin 38, A part hole 44 for inserting the wire 34 is formed.

On the other hand, in the front step (ST5) to remove the burrs generated in the soft copper foil 40 and the foreign matter remaining in the parts hole when forming the part hole 44, the copper foil 40 In order to increase the compressibility of the photosensitive dry film (D / F: Dry Film) to the surface of the substrate 32 and the copper foil 40 to clean the surface of the brush (B) to form the necessary surface roughness (Surface roughness) is formed. .

In the laminating step (ST6), the photosensitive dry film 46 for forming a circuit pattern on the surfaces of the substrate 32 and the copper foil 40 is hot roller of 90 to 110 ° C. After thermal compression, the photoresist 50 is applied to the non-hardened portion on the substrate 32 on which the photosensitive dry film 46 is pressed. In the state, it passes through an exposure machine, and irradiates and hardens ultraviolet (UV) light to the required part of the dry film 46 on the board | substrate 32. FIG.

In the photosensitive dry film 46, the exposure dose of ultraviolet rays to the hardened portion is preferably 20 to 60 mj / cm 2.

On the other hand, in the D / F development / corrosion / peeling step (ST8) of the present invention by removing the non-hardened portion to which the photoresist 50 is applied in a developer solution to remove the dry film corresponding to the hardened portion on the substrate 32 Leaving only the basic circuit pattern to be formed.

In this state, unnecessary copper foil except for the soldering portion 52 corresponding to the surface edge of the part hole 44 is removed by corrosion, and the dry film remaining on the surface of the soldering portion 52 is peeled off.

In the PSR printing step ST9, a photo solder resist is formed on the surface of the substrate except for the soldering portion 52 so that the circuit pattern formed on the substrate 32 and the surface of the substrate 32 are not corroded or damaged by an external environment. Ink (PSR: Photo Solder Resist ink: 54) is applied.

In the soldering step (ST10) of the present invention, a drying → exposure → developing → drying process is performed on the substrate printed with the PSR ink 54, and the part hole 44 formed at the center of the through hole 36 is formed. After inserting the wire 34 through, one end of the wire 34 protruding outward is soldered with the soldering portion 52.

The manufacturing method of the printed circuit board according to the present invention can be applied to the manufacture of both single-sided PCB, double-sided PCB or multilayer PCB.

When the method of manufacturing a printed circuit board according to the present invention is applied, since the insulating resin 38 is filled in the through hole 36 formed in the substrate 32 by a hot press method, the number of work steps is greatly reduced. As a result, the work time by process is also significantly reduced, which leads to a dramatic increase in productivity per unit time and a significant reduction in production costs.

In addition, when the printed circuit board to which the present invention is applied is applied, the insulating resin is evenly formed on the inner wall surface of the through hole corresponding to the circumferential surface of the part hole, thereby improving the insulating property during use.

32: substrate 36: through hole
38: insulating resin 40: copper foil
44: part ball 46: dry film (D / F)
50: photoresist 52: soldering portion
54: PSR ink.

Claims (3)

A through hole forming step having a relatively thick thickness and forming a through hole 36 at each mounting position of an element or a wire 34 on a substrate 32 made of a thermally conductive metal or a nonferrous metal material cut to a predetermined size (ST1). )Wow;
In the state where the insulating resin 38 and the copper foil 40 were sequentially arranged on the surface, the rear surface, or both the front surface and the rear surface of the through hole 36 formed on the substrate 32. An insulating resin plugging step (ST2) pressurized by the press 42 to fill the insulating resin 38 into the through hole 36;
A non-filling cavity forming step (ST3) of forming a non-filling cavity in which the resin is not filled by using a press mold method with respect to the substrate 32 to which the copper foil 40 is adhered through the insulating resin 38;
A part hole forming step (ST4) of forming a part hole 44 for inserting an electronic element or a wire 34 in the center of the through hole 36 filled with the insulating resin 38;
When forming the part hole 44, the burr generated in the soft copper foil 40 and foreign substances remaining in the part hole are removed, and a photosensitive dry film (D / F) on the surface of the copper foil 40 is removed. A step (ST5) of forming a surface roughness necessary while washing the surfaces of the substrate 32 and the copper foil 40 with a brush B in order to increase the compressibility of the dry film;
Laminating step of thermally compressing the photosensitive dry film 46 for forming a circuit pattern on the surface of the substrate 32 and the copper foil 40 with a hot roller 48 of 90 to 110 ° C. ST6);
The photoresist 50 is applied to the non-hardened portion on the substrate 32 on which the photosensitive dry film 46 for forming the circuit pattern is pressed, and then the substrate is passed through an exposure machine. A D / F exposure step (ST7) for irradiating and curing ultraviolet rays (UV) with respect to a required portion of the dry film 46 on (32);
The photoresist 50 is removed by dissolving the uncured portion coated therein with a developer, and only the dry film corresponding to the hardened portion remains on the substrate 32 to form a basic circuit pattern. D / F development / corrosion / peeling step of removing unnecessary copper foil except for soldering portion 52 corresponding to the edge of the surface, while peeling off the dry film remaining on the surface of the soldering portion 52 (ST8);
Photo Solder Resist (PSR) on the surface of the substrate except for the soldering portion 52 in order to prevent the circuit pattern formed on the substrate 32 and the surface of the substrate 32 from being corroded or damaged by an external environment. a PSR printing step ST9 for applying ink 54);
The substrate printed with the PSR ink 54 is dried, exposed, developed, and dried. Then, the wire 34 is inserted through the part hole 44, and one end of the wire 34 protrudes outward. Method of manufacturing a printed circuit board comprising a soldering step (ST10) for soldering the part and the soldering portion (52). The method of claim 1,
In the insulating resin plugging step (ST2), the hot press 42 is pressed for 2 to 3 hours at a pressure of 20 to 25 kg / cm < 2 > and a temperature of 170 to 180 < 0 > C, so that the insulating resin 38 becomes the substrate 32. Method for manufacturing a printed circuit board, characterized in that to be plugged into the through-hole 36 on the top. The method of claim 1,
In the D / F exposure step (ST7), the exposure amount of ultraviolet rays to the hardened portion of the dry film 46 on the substrate 32 is 20 to 60mj / ㎠.

Images