KR20030011434A - Manufacturing method for hidden laser via hole of multi-layered printed circuit board - Google Patents

Abstract

PURPOSE: A method for fabricating a hidden laser via hole of a multi-layered PCB(Printed Circuit Board) is provided to improve a soldering characteristic of a via pad and a bonding characteristic when electronic components are mounted on the multi-layered PCB. CONSTITUTION: A multi-layered substrate of desired layers is formed by laminating a plurality of layers. A laser via hole is formed by performing a laser drilling process. The first external conductor layer is formed by performing the first panel plating process on the multi-layered substrate. A laser via(120) is formed by performing a plugging process with silver paste or copper paste or conductive filling agent. A polishing process for the laser via(120) is performed. The second external conductive layer is formed on the first external conductive layer and the laser via(120) by performing the second panel plating process on the substrate. A plurality conductive patterns(110a,114a) are formed on the second external conductive layer.

Description

MANUFACTURING METHOD FOR HIDDEN LASER VIA HOLE OF MULTI-LAYERED PRINTED CIRCUIT BOARD}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer printed circuit board, in particular plugging and polishing, or plugging and polishing, and simultaneously plating a laser via hole formed by laser drilling for component mounting. By forming the via and the conductor layer, not only the contact between the electronic parts such as IC (Integrated Circuit) or BGA (Ball Grid Array) and via pads, but also the uniformity of the via pads can be increased, and the entire via pads can be increased. The present invention relates to a method for manufacturing a hidden laser via hole of a multilayer printed circuit board having high reliability by improving the reinforcing properties and the soldering properties thereof.

Printed circuit boards are the most basic components of many electronic products that are currently manufactured. In recent years, thin and thin multilayer printed circuit boards have been used for mobile phones, PCS, IMT 2000, notebooks, palmtops, camcorders, and BGAs (ball grid array). (CSP), chip scale packaging (CSP), multi chip module (MCM), and the like have been widely applied to package substrates.

According to the known manufacturing process of a multilayer printed circuit board, a process of forming a multilayer substrate with a desired number of layers by laminating a plurality of layers (a1-a9) and a laser drilling process of processing via holes for electrical connection between the multilayer substrates (a10-a18) and a step (a19-a23) of plating the via hole processed by the laser drill to form an external pattern for power distribution is required. Such a conventional manufacturing process is illustrated in FIGS. 1A to 1G. Is shown.

1A to 1G, the process of forming the multilayer substrate includes a process (a1) of processing the buried via hole 2 in the double-sided substrate 1 by a mechanical drilling operation, and the buried via hole is Forming a first conductor layer 3 on the inner circumferential surface of the buried via hole and the upper and lower surfaces of the buried via hole by applying one or more platings to the formed double-sided substrate; and a jig (JIG) inside the plated buried via hole. A process of plugging the filler 4 using a3, a step of curing the filler for a predetermined time at a predetermined temperature (a4), and polishing the cured filler to form buried vias 4a. Process (a5), laminating the film (5) on the buried via (4a) and the first conductor layer (3), and forming an image on the applied film (5) Exposing the first conductor layer 3 by exposure and development (a7), and the exposed first conductor A step (a8) of etching the layer to form the first conductor pattern 3a of a desired shape, and a step (a9) of peeling the film from the conductor pattern. By repeatedly performing the above steps (a1) to (a9), it is possible to form a substrate having a multi-layered conductor pattern as necessary.

The laser drilling process is performed by first laminating a resin coated copper foil (RCC) having an insulating resin 6 coated on one surface of a copper foil 7 to a multilayer substrate formed as described above by high temperature and high pressure. A step (a10), a step (a11) of laminating the film (8) on the surface of the laminated RCC, an image is formed on the applied film (8) and the copper foil of the RCC by exposure and development (7) exposing (a12), the process of etching the exposed copper foil to form a second conductor pattern 7a of a desired form and peeling the film from the second conductor pattern (a13), and the pattern (A14) secondary laminating the RCC (resin coated copper foil) 9, 10 by the high temperature and high pressure on the thinned conductor pattern, and laminating the film 11 on the surface of the secondary laminated RCC. laminating the process (a15), and forming an image on the applied film (11) and exposing the RCC by exposure and development. (A) exposing (10), and etching the exposed copper foil to form a third conductor pattern 10a and a laser point 12 of a desired shape and to peel off the film from the third conductor pattern ( a17) and a step (a18) of forming a laser via hole 13 by performing laser drilling on the formed laser point.

The step of forming the power distribution pattern includes a step (a19) of forming the outer conductor layer 14 by performing panel plating on the formed third conductor pattern and the laser via hole, and the film 15 on the surface of the outer conductor layer. Laminating the layer (a20), forming an image on the coated film (15) and exposing the outer conductor layer (14) by exposure and development (a21), and the exposed outer conductor Etching the layer 14 to form an outer conductor pattern 14a and via pad 17 having a desired shape and peeling the film from the outer conductor pattern (a22); and screening the portion where the outer conductor pattern is etched. The process (a23) which applies the soldering resist 16 by printing is included.

A photograph of a multilayer printed circuit board, which can be completed by the conventional manufacturing process as described above, is shown in FIG. 2A and an enlarged photograph of a part thereof is shown in FIG. 2B, and a via pad 17 formed on the multilayer printed circuit board is shown. And an enlarged cross section of the laser via hole 13 formed therein is shown in FIG. 3.

Referring to the technical problems of the multilayered printed circuit board completed by the prior art with reference to Figures 2a, 2b and 3, the conventional laser via hole has a small contact area with a variety of fine electronic components, the electronic component and the laser Since it has a structure that reduces the bonding property with the via hole, there is a problem that the electronic parts are not mounted and bonded correctly in the laser via hole, thereby deteriorating the reliability of the multilayer printed circuit board, and also when mounting ICs and BGAs. Due to the solder ball formed on the bottom, there was a problem such as a short between the parts and the solder ball.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a first object of the present invention is to increase the contact area between a laser via hole formed in a multilayer printed circuit board and an electronic component mounted on a substrate in order to mount the electronic component. Improves contact and bonding characteristics when mounting electronic components on printed circuit boards, improves uniformity of external conductor patterns formed for distribution, and improves contact and bonding characteristics when mounting electronic components on multilayer printed circuit boards. In addition, the present invention provides a method for manufacturing a hidden laser via hole of a multilayer printed circuit board, which may improve soldering characteristics of a via pad.

The second object of the present invention is to expand the contact area between the laser via hole formed in the multilayer printed circuit board and the electronic component mounted on the substrate to mount the electronic component, thereby contacting and bonding characteristics when mounting the electronic component on the multilayer printed circuit board. To improve the contact and bonding characteristics when mounting electronic components on multilayer printed circuit boards, as well as reinforce the via pads and solder the via pads. To provide a method for manufacturing a hidden laser via hole of a multilayer printed circuit board that can improve the.

Figure 1a to 1g is a conventional multilayer printed circuit board manufacturing process diagram

2A and 2B are enlarged views showing a laser via hole photograph of a multilayered printed circuit board completed by a conventional manufacturing process and a partial region A of the photograph.

3 is a cross-sectional view of a laser via hole of a multilayer printed circuit board completed by a conventional manufacturing process.

Figures 4a to 4h is a manufacturing process diagram of a multilayer printed circuit board according to an embodiment of the present invention

5A and 5B are enlarged views of a hidden laser via hole photograph of a multilayered printed circuit board completed by the manufacturing process of the present invention and a partial photo area B thereof.

6 is a cross-sectional view of a hidden laser via hole of a multilayer printed circuit board completed by the manufacturing process of the present invention.

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

101: double-sided substrate 102: buried via hole

103, 114, 121: conductor layer 103a, 107a, 110a, 114a: conductor pattern

104: Filling 104a: Buried Via

105, 108, 111, 115: film 106, 109: adhesive insulating resin

107, 110: copper foil 120: laser point

113: laser via hole 116: solder resist

120: laser via

The first object of the present invention is a method for manufacturing a multilayer printed circuit board comprising a laser drilling process for processing a via hole by a laser drill for mounting an electronic component, the hole plug (plugging) in the laser via hole formed for mounting the component Forming a laser via; It can be achieved by an embodiment of a method for manufacturing a hidden laser via hole of a multilayer printed circuit board, including the step of polishing the laser via.

According to a second aspect of the present invention, a method of manufacturing a multilayer printed circuit board including a laser drilling process of processing a via hole by a laser drill for mounting an electronic component, the first panel plating is performed on a substrate on which the laser via hole is processed. Forming a primary outer conductor layer for forming a power distribution pattern; Forming a laser via by plugging a laser via hole in which the primary outer conductor layer is formed; Polishing the laser via; And forming a secondary outer conductor layer on the primary outer conductor layer and the laser via to form a power distribution pattern by performing secondary panel plating on the substrate on which the laser via is polished. It can be achieved by an embodiment of a method for manufacturing a hidden laser via hole of a substrate.

Further, in each of the embodiments of the present invention, the laser via is formed of a conductive paste, a silver paste or a copper paste, or a conductive resin, and the secondary outer conductor layer is formed of a copper plating layer. It can be achieved even more efficiently.

These objects of the present invention and the technical features and advantages of each embodiment for achieving the objects will be more readily understood by reference to the accompanying drawings and the following detailed description.

The present invention in the following is a multilayer substrate having at least three or more layers of conductor patterns manufactured using a double-sided substrate, and in a multilayer printed circuit board for processing a hidden laser via hole by laser drilling to mount electronic components on the multilayer substrate. The preparation method of is proposed as a preferable Example. Particularly, in the present specification, a case in which three conductive patterns are formed inside the multilayer substrate will be described, but the technical idea of the present invention is not limited thereto and may be variously modified and modified by those skilled in the art. .

4A to 4H are overall process diagrams for explaining a method of manufacturing a hidden laser via hole of a multilayer printed circuit board according to an exemplary embodiment of the present invention, wherein a plurality of layers are stacked to form a multilayer substrate having a desired number of layers ( b1-b9), a laser drilling process (b10-b18) for processing the laser via hole 113 for interlayer electrical connection and component mounting of the multilayer substrate, and primary panel plating on the substrate on which the laser via hole is processed. (B19) forming a primary outer conductor layer 114 for forming a power distribution pattern, and a hole in the laser via hole in which the primary outer conductor layer is formed is formed of a silver paste or a copper paste or a conductive resin filler. A process of forming a laser via 120 by plugging (b20), a process of polishing the laser via (b21), and a substrate on which the laser via is polished. Forming a secondary outer conductor layer 121 on the primary outer conductor layer and the laser via to form a distribution pattern by performing primary panel copper plating (b22), and to the secondary outer conductor layer. An embodiment of a method for manufacturing a hidden laser via hole of a multilayer printed circuit board, including a process of forming a pattern for the substrate (b23-b26), is illustrated. According to this process diagram, the best model of the present invention can be implemented.

In particular, by selectively performing some of the manufacturing processes illustrated in FIG. 4, it is possible to selectively achieve the first or second object of the present invention.

That is, the first object of the present invention is to form a multilayer substrate with a desired number of layers by stacking a plurality of layers (b1-b9), and laser via holes 113 for interlayer electrical connection and component mounting of the multilayer substrate. Laser drilling process (b10-b18), and forming a primary outer conductor layer 114 for forming a distribution pattern by performing primary panel plating on the substrate on which the laser via hole is processed (b19). And (b20) forming a laser via 120 by plugging a silver paste, a copper paste, or a conductive resin-type filler into the laser via hole on which the primary outer conductor layer is formed. Manufacturing a hidden laser via hole in a multilayer printed circuit board, the method comprising: polishing a laser via (b21), and forming a pattern for power distribution in the laser via and the primary outer conductor layer (b23-b26). It can be achieved by embodiments of the method.

In each embodiment of the present invention, the steps (b1-b9) for forming the multilayer substrate, the laser drilling steps (b10-b18), and the steps (b19, b23-b26) for forming the power distribution pattern have already been performed. Since the same as the conventional manufacturing process described in Figures 1a to 1g, the detailed description thereof will be omitted, and the flow operation of the manufacturing process according to each embodiment of the present invention with reference to Figures 4a to 4h below Explain.

First, the buried via hole 102 is processed (b1) on the double-sided substrate 101 by mechanical drilling, and the plating is performed one or more times on the double-sided substrate 101 on which the buried via hole 102 is formed. The first conductor layer 103 is formed on the inner circumferential surface of the buried via hole and the upper and lower surfaces of the substrate (b2).

Next, filling the filler 104 using a jig (JIG) in the plated buried via hole 102 (b3), curing the filler for a predetermined time at a predetermined temperature (b4), and then the cured The filler is ground to form a uniform buried via 104a with a top and bottom surface (b5).

Subsequently, the film 105 is laminated (b6) on the buried via 104a and the first conductor layer 103, and an image is formed on the film 105 to expose the first conductor layer 103 by exposure and development. The portion to be etched is exposed (b7).

Thereafter, by etching the exposed first conductor layer, a first conductor pattern 103a having a desired shape is formed (b8), and the film 105 is peeled off from the conductor pattern (b9) to form one conductor pattern. A printed circuit board having the same is manufactured.

Thereafter, by repeatedly performing the steps (b1) to (b9) according to the user specification, a substrate having a multilayer conductor pattern as necessary is formed.

Next, on the multilayer substrate formed as described above, the RCC having the insulating resin 106 coated on one surface of the copper foil 107 is first laminated (b10) by high temperature and high pressure, and the film 108 is again placed on the surface thereof. By coating (b11), the copper foil 107 of the portion to be etched of the RCC is exposed (b12) by exposure and development using the applied film 108.

Thereafter, the exposed copper foil is etched to form a second conductor pattern 107a of a desired shape, and then the film 108 is peeled off (b13).

RCCs 109 and 110 are second-laminated (b14) on the film-peeled conductor pattern by high temperature and high pressure, and the film 111 is applied to the surface of the RCC (b15) to use the coated film 111. By exposure and development, the copper foil 110 of the portion to be etched of the RCC is exposed (b16).

The exposed copper foil 110 is etched to form the third conductor pattern 110a and the laser point 112 of a desired shape, and then the film is peeled off (b17) from the third conductor pattern.

Thereafter, laser drilling is performed on the formed laser point 112 to form a laser via hole 113 (b18).

The primary outer conductor layer 114 is formed by performing primary panel plating on the formed third conductor pattern 110a and the laser via hole 113 (b19).

The laser via 120 is formed by plugging the laser via hole 113 having the primary outer conductor layer 114 with a silver paste, a copper paste, or a conductive resin-type filler (b20). .

After polishing the laser via 120 to make the upper and lower surfaces uniform (b21), the secondary external conductor for forming a power distribution pattern is formed by plating the second panel again on the substrate on which the laser via is polished. A layer 121 is formed on the primary outer conductor layer and the laser via (b22).

Thereafter, after the film 115 is coated (b23) on the surface of the secondary outer conductor layer, an image is formed on the coated film 115 and the secondary outer conductor layer 121 is exposed by exposure and development. Exposure (b24).

After etching the exposed outer conductor layer 121 and the two conductor layers (110,114) below it to form a desired outer conductor pattern 121a and two conductor patterns (110a, 114a) below for power distribution The film is peeled off (b25) from the pattern.

Then, the solder resist 116 is applied (b26) to the portion where the secondary outer conductor pattern is etched by screen printing.

Thus, the laser via hole of the multilayer printed circuit board which can achieve the first and second objects of the present invention, which is the best model according to the present invention, is completed, and the multilayer printed circuit board which can be manufactured by these manufacturing processes is shown in FIG. 5A. A hidden laser via hole photograph is shown in FIG. 5B, a partially enlarged view of the hidden laser via hole photograph is shown in FIG. 6, and a cross section of the hidden laser via hole is shown in FIG. 6, respectively. According to these drawings, as previously described, it can be seen that the contact area between the laser via hole formed in the multilayer printed circuit board and the electronic component mounted on the substrate is widened to mount the electronic component by the laser via hole plugging process. Therefore, it is possible not only to improve contact and bonding characteristics when mounting electronic components on multilayer printed circuit boards, but also to increase conductivity and uniformity of external conductor patterns formed for power distribution, thereby reinforcing the entire via pads and the via pads. Benefits such as improving soldering properties can be obtained.

Of course, from the best model according to the present invention, the laser via hole 113 is formed by plugging the laser via hole 113 in which the primary outer conductor layer 114 is formed with a filler to form the laser via 120 (b20). And then polishing the laser via 120 to uniformize the upper and lower surfaces thereof, thereby increasing the contact area between the laser via hole and the electronic components mounted on the substrate and forming an external structure for power distribution. Since the uniformity of the conductor pattern can be improved, the first purpose of the present invention is not only to improve contact and bonding characteristics when mounting electronic components on a multilayer printed circuit board, but also to improve soldering characteristics of via pads. .

The present invention is not limited to the embodiments described above, and various modifications and changes can be made by those skilled in the art, which are included in the spirit and scope of the present invention as defined in the appended claims.

According to the present invention configured as described above, by filling a laser via hole formed to a predetermined depth by laser drilling on a multi-layer printed circuit board, the area that can be soldered can be widened, and the cream due to the adjacent laser via hole when soldering to the via pad is obtained. Because it prevents solder flow and prevents ink splashing during screen printing, it is possible to mount a part so that the function of the part and the part can be normally performed. Therefore, there is an advantage of reducing the contact failure rate. In addition, copper plating is applied thereon to solve the problems arising in the process of mounting various electronic components, and the mounted electronic components can be accurately functioned.

As a result, the laser via hole manufacturing method according to each embodiment of the present invention not only improves a printed circuit board manufacturing technology according to rapidly changing electronic technology development, but also accurately mounts and bonds the BGA and various fine electronic parts of the electronic parts. Because of this, there is an advantage that can contribute to reducing even the smallest error.

Claims (7)

In the method of manufacturing a multilayer printed circuit board comprising a laser drilling process for processing via holes by a laser drill for mounting electronic components, Forming a laser via by plugging a laser via hole formed for mounting the component; A method of manufacturing hidden laser via holes in a multilayer printed circuit board, the method comprising grinding the laser via. In the method of manufacturing a multilayer printed circuit board comprising a laser drilling process for processing via holes by a laser drill for mounting electronic components, Forming a primary outer conductor layer for forming a power distribution pattern by performing primary panel plating on the substrate on which the laser via hole is processed; Forming a laser via by plugging a laser via hole in which the primary outer conductor layer is formed; Polishing the laser via; And forming a second outer conductor layer on the first outer conductor layer and the laser via to form a power distribution pattern by performing secondary panel plating on the substrate on which the laser via is polished. A method for manufacturing hidden laser via holes in a multilayer printed circuit board. The method of claim 1 or 2, wherein the laser via is formed of a conductive paste. The method of claim 3, wherein the conductive paste is a silver paste. 4. The method of claim 3, wherein the conductive paste is a copper paste. The method of claim 3, wherein the conductive paste is a conductive resin. 3. The method of claim 2, wherein the secondary outer conductor layer is formed of a copper plating layer.