KR100657410B1 - Manufacturing multi-layer pcb - Google Patents

Abstract

A method for manufacturing a multi-layer printed circuit board is provided to implement a high integrated interconnection of a printed circuit board by performing a precise ink-jet printing. A method for manufacturing a multi-layer printed circuit board includes the steps of: combining a first paste bump on a predetermined location of a substrate(100); stacking the first insulation layer on the substrate so that the first paste bump penetrates the first insulation layer(110); compressing the first paste bump corresponding to the height of the first insulation layer(120); and printing a first circuit pattern on the surface plane of the first insulation layer through an ink-jet scheme(130).

Description

Manufacturing method of multilayer printed circuit board {Manufacturing multi-layer PCB}

1 is a cross-sectional view showing a paste bump substrate according to the prior art.

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

3 is a flowchart illustrating a manufacturing process of a multilayer printed circuit board according to a first exemplary embodiment of the present invention.

Figure 4 is a flow chart showing a multi-layer printed circuit board manufacturing process according to a second embodiment of the present invention.

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

7: outer layer circuit 8: base pattern

9: copper foil 10: carrier metal layer

12, 22: circuit pattern 14, 24: paste bump

20, 30: insulation layer

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

In conventional multilayer printed circuit boards, an inner layer circuit is formed by applying an additive method or a subtractive method to a surface of a core substrate such as a copper clad laminate (CCL), and an insulating layer and a metal layer are sequentially stacked. It is manufactured by forming the outer layer circuit in the same way as the inner layer circuit while building (up).

Due to the development of electronic components, there is a demand for a technology capable of improving performance of high density interconnection (HDI) substrates to which electrical patterns of circuit patterns and fine circuit wiring are applied for increasing the density of printed circuit boards. That is, in order to improve the performance of the HDI substrate, a technique for securing the electrical conduction technology and the degree of freedom of design between circuit patterns is required.

In the manufacturing process of a multilayer printed circuit board according to the prior art, first, a via hole is drilled into a core substrate such as CCL by mechanical drilling, and then chemical copper plating and / or electroplating is performed on the surface of the core substrate and the inner circumferential surface of the via hole. After forming a plating layer, and the inner layer circuit is formed by applying an additive method or a subtractive method, etc. to the surface of the core substrate, the circuit is inspected.

Next, build-up is performed by surface treatment and lamination of RCC (resin coated copper), and a via hole for interlayer electrical connection of a circuit pattern is formed by laser drilling, and the surface of the via hole is plated and then laminated. Form an outer layer circuit on the surface and inspect the circuit. In order to add a layer of a circuit pattern, surface treatment, RCC, etc. are laminated again, a via hole is formed, the surface of the via hole is plated, and an outer layer circuit is formed. This build-up process is performed to form as many circuit pattern layers as desired.

However, such a conventional multi-layer printed circuit board manufacturing process, such as the request for low cost (low cost) in accordance with the falling price of the application products such as mobile phones, the request for shortening the lead time (lead-time) to increase the mass production, etc. There is a problem that does not satisfy, there is a need for a new manufacturing process that can solve this problem.

Meanwhile, in order to simplify the complicated process of the prior art and to manufacture a multilayer printed circuit board quickly and inexpensively by batch lamination, a bump is printed by printing a paste on the copper foil 3 as shown in FIG. 1. A so-called 'B2it' (Buried bump interconnection technology) technology has been commercialized so that a lamination process can be performed simply and easily by forming a 2 'and stacking the insulating material 1 thereon to prepare a paste bump substrate in advance.

The present invention provides a method for manufacturing a multilayer printed circuit board using only inkjet technology and paste bump technology without requiring plating and drilling processes.

According to one aspect of the invention, (a) bonding the first paste bump to a predetermined position on the substrate, (b) laminating the first insulating layer on the substrate so that the first paste bump penetrates the first insulating layer Multilayer printing comprising the steps of: (c) pressing the first paste bump corresponding to the height of the first insulating layer, and (d) printing the first circuit pattern on the surface of the first insulating layer by an inkjet method. A circuit board manufacturing method is provided.

After step (d) (e) coupling the second paste bump to a predetermined position of the first circuit pattern, (f) second insulation on the first insulating layer such that the second paste bump penetrates the second insulating layer Laminating the layers, (g) pressing the second paste bump corresponding to the height of the second insulating layer, and (h) printing the second circuit pattern on the surface of the second insulating layer by an inkjet method. It may further include.

That is, the process of forming the first circuit pattern layer may be repeated to build up the second circuit pattern layer, and the above-described process may be repeated by the required number of circuit pattern layers to manufacture a multilayer printed circuit board. Can be.

For electrical connection between the multilayer circuit pattern layers, it is preferable that the surface of the first paste bump is exposed to the surface of the first insulating layer and the first circuit pattern is electrically connected to the first paste bump.

As a substrate, a carrier metal layer having a base pattern formed on a surface thereof may be used. The base pattern may be formed by inkjet printing like other circuit patterns, and thus the process may be performed without any additional device. Meanwhile, since the first paste bump is coupled to the base pattern and the paste bump serves as an electrical path between the circuit pattern layers, the land portion may be formed at a position where the first paste bump is coupled.

If the carrier metal layer is used as the substrate, the carrier metal layer can be removed from the printed circuit board after step (h). Since the carrier metal layer serves as a structural support for stacking multilayer circuit pattern layers by repeating inkjet printing and paste bump formation, after the multilayer printed circuit board is formed, the carrier metal layer may be separated therefrom and removed.

Meanwhile, without removing the carrier metal layer, a cavity may be drilled in the carrier metal layer after step (h), and an electronic device may be embedded in the cavity. In this case, a part of the base pattern may be an electrode pattern electrically connected to the electrodes of the electronic device to be embedded.

In addition, a copper foil may be used as the substrate, and bonding the paste bumps to the copper foil and laminating an insulating layer corresponds to a paste bump substrate manufacturing process according to the above-described 'B2it' method. That is, according to another aspect of the present invention, there is provided a method of manufacturing a multilayer printed circuit board by forming a paste bump substrate and then laminating a circuit pattern layer thereon. Thus, multilayer printing is performed using the paste bump substrate as the outermost layer. In the case of manufacturing a circuit board, after the lamination process, an outer layer circuit may be formed by applying a process such as etching to the outermost copper sheet.

As described above, when the outermost layer is used as a paste bump substrate and the circuit pattern is formed on the copper foil, the rigidity of the printed circuit board may be improved as compared with the case where the circuit pattern is formed only by inkjet printing.

Hereinafter, a preferred embodiment of a method for manufacturing a multilayer printed circuit board according to the present invention will be described in detail with reference to the accompanying drawings. In the description with reference to the accompanying drawings, the same components will be denoted by the same reference numerals regardless of the reference numerals and redundant description thereof will be omitted.

2 is a flowchart illustrating a method of manufacturing a multilayer printed circuit board according to an exemplary embodiment of the present invention, and FIG. 3 is a flowchart illustrating a process of manufacturing a multilayer printed circuit board according to a first embodiment of the present invention. Referring to FIG. 3, the base pattern 8, the carrier metal layer 10, the circuit patterns 12 and 22, the paste bumps 14 and 24, and the insulating layers 20 and 30 are illustrated.

In this embodiment, a carrier metal is used as a support substrate, and a base pattern 8, which is a circuit pattern, is formed thereon by an inkjet method, and silver paste or the like is used for electrical conduction between the circuit pattern layers. After the paste bumps are formed, the paste bumps are laminated so as to penetrate through the insulating layer to build up the circuit pattern layer. That is, the circuit pattern is formed by applying an inkjet printing technique and applying the 'B2it' method in the process of laminating paste bumps and insulating layers.

First, the carrier metal layer 10 as shown in FIG. 3 (a) is used as a substrate, and the base pattern 8 is printed thereon, as shown in FIG. Inkjet printing technology has been mainly used in office automation (OA) field and has been mainly used in fields such as packaging material marking and garment printing. However, the development of functional ink containing nano metal particles such as silver and nickel In addition, the application possibilities are gradually expanded, and are currently being applied to the formation of circuit patterns of printed circuit boards using functional inks including nano metal particles. The carrier metal layer 10 corresponds to a base layer for forming the base pattern 8 by inkjet printing.

The base pattern 8 includes a land portion formed at a portion to which the paste bumps 14 for interlayer electrical conduction are to be coupled, and the base pattern is formed so that the land portion is formed at an appropriate position in consideration of the position where the paste bumps 14 are to be coupled in advance. Print (8).

After the base pattern 8 is printed on the surface of the carrier metal layer 10, as shown in FIG. 3C, the paste bumps 14 for electrical conduction between the circuit pattern layers are coupled to a predetermined position (100). . The paste bump 14 is made of a conductive paste such as silver paste, and the paste bump 14 is coupled to a position where a land portion is formed in the base pattern 8 for electrical conduction between the circuit pattern layers as described above. In the present embodiment, the paste bump 14 plays the same role as the IVH in the conventional multilayer printed circuit board.

Next, as illustrated in FIG. 3D, the insulating layer 20 is laminated on the carrier metal layer 10 so that the paste bump 14 penetrates the insulating layer 20 (110). In this process, a so-called 'B2it' method of forming a 'paste bump substrate' by stacking the insulating layer 20 on a substrate on which the paste bump 14 is formed is applied, and using the penetrator for the 'B2it' method. ) Is laminated through the paste bump 14.

Next, the paste bumps 14 are pressed in correspondence to the heights of the insulating layers 20 stacked as shown in FIG. 3E (120). This is to match the height of the paste bump 14 that penetrates the insulating layer 20 and protrudes above the surface of the insulating layer 20 to be equal to the height of the insulating layer 20. The compression of the paste bump 14 is performed in a mechanical manner, and may be applied to existing coining equipment. If the insulating layer 20 is directly stacked without pressing the paste bumps 14, a part of the paste bumps 14 may protrude over the surface of the insulating layer 20, thereby making it difficult to sequentially stack the circuit pattern layer. have.

After the paste bump 14 is pressed to flatten the surface of the insulating layer 20, the circuit pattern 12 is printed on the surface of the insulating layer 20 by an inkjet method as shown in FIG. (130). The printing process of the circuit pattern 12 is the same as the formation process of the base pattern 8 mentioned above, and one circuit pattern layer is formed by this.

Through this process, one circuit pattern layer is formed. The first circuit pattern layer is a state in which the circuit pattern 12 is printed on a flat surface consisting of an insulating layer 20 and an upper surface of the paste bump 14 for interlayer conduction.

In order to form a multi-layer circuit pattern, the paste bumps 24 are again bonded to predetermined positions of the first circuit pattern layer as shown in FIG. 3G, and the paste bumps 24 penetrate as shown in FIG. The insulating layer 30 is laminated as much as possible, the paste bumps 24 are pressed by the height of the insulating layer 30 to form a flat surface as shown in FIG. 3 (i), and then again as shown in FIG. 3 (j). The circuit pattern 22 is printed by the inkjet method.

This is equivalent to repeating the process of forming the first circuit pattern layer again, and thus, in forming the multilayer printed circuit board according to the present embodiment, the process described above as many as the number of circuit pattern layers required as shown in FIG. By repeating to produce a multilayer printed circuit board.

According to the present embodiment, when the circuit pattern layer of one layer is formed, the surface is formed of the circuit pattern 12, and electrical conduction between the circuit pattern layers is performed in the process of bonding the paste bumps 24 to the predetermined positions again. In order to implement, it is preferable to determine the bonding position of the paste bump 24 so that the land portion of the circuit pattern 12 is connected to the paste bump 24. As such, when the land portion of the circuit pattern 12 and the paste bump 24 are continuously connected in the vertical direction, a via hole penetrating the entire printed circuit board may be realized, such as a so-called 'stack via'.

When a plurality of circuit pattern layers are stacked by repeating the above-described process, a multilayer printed circuit board is formed by pressing them collectively as shown in FIG. 3 (l), and as a base for inkjet printing as shown in FIG. 3 (m). The manufacture of the multilayer printed circuit board is completed by removing the carrier metal layer 10 corresponding to the layer.

On the other hand, the carrier metal layer 10 is not necessarily removed, and may be used as a core substrate in which electronic devices are embedded to manufacture a high density printed circuit board. That is, after the multilayer printed circuit board is formed as shown in FIG. 3 (l), a cavity (not shown) is drilled in the carrier metal layer 10, and an electronic device is embedded in the cavity.

Since the carrier metal layer 10 used as the substrate is a thick copper thin plate, a cavity may be drilled therein by etching or drilling, and an electronic device may be embedded to implement a high density printed circuit board. The carrier metal layer serves as a structural support to increase the rigidity of the entire printed circuit board and the heat dissipation function that not only provides a space in which the electronic device is embedded, but also emits heat generated from the electronic device to the outside.

When the cavity is drilled in the carrier metal layer 10 and the electronic device is embedded in the cavity, the electrode pattern to be connected to the electrode of the electronic device is included in the process of forming the base pattern 8 on the surface of the substrate by an inkjet method. good. In this way, the carrier metal layer 10 may be formed to form a cavity, the electrode of the electronic device may be electrically connected to the electrode pattern, and the cavity may be filled with a filler to easily manufacture the device-embedded multilayer printed circuit board.

4 is a flowchart illustrating a manufacturing process of a multilayer printed circuit board according to a second exemplary embodiment of the present invention. Referring to FIG. 4, the outer circuit 7, the copper foil 9, the circuit patterns 12 and 22, the paste bumps 14 and 24, and the insulating layers 20 and 30 are illustrated.

Unlike the first embodiment in which the base pattern 8 is printed on the carrier metal layer 10 and used as a substrate, the second embodiment bonds the paste bumps 14 to the copper foil 9 to form a paste bump substrate. After stacking the circuit pattern layers as many times as necessary, the copper foil layer is formed on the outermost layer to form the outer circuit 7 so that the process of removing the carrier metal layer 10 is omitted and the rigidity of the multilayer printed circuit board is eliminated. It is distinguished from the first embodiment in that it is improved.

First, the copper foil plate 9 as shown in FIG. 4A is used as a substrate, and the paste bumps 14 are bonded thereon as shown in FIG. 4B, and the paste bumps 14 as shown in FIG. 4C. The insulating layer 20 is laminated so as to penetrate the insulating layer 20 to form a paste bump substrate. The paste bump 14 is made of a conductive paste such as silver paste, and serves as IVH in a conventional multilayer printed circuit board.

In order to form the paste bump substrate, the 'B2it' method may be applied as described above, and the insulating layer 20 is laminated through the paste bump 14 by using a penetrator for the 'B2it' method.

Next, the paste bump 14 is pressed in correspondence with the height of the insulating layers 20 stacked as shown in FIG. This is to match the height of the paste bump 14 that penetrates the insulating layer 20 and protrudes above the surface of the insulating layer 20 to be equal to the height of the insulating layer 20. The compression of the paste bump 14 is performed in a mechanical manner, and may be applied to existing coining equipment. If the insulating layer 20 is directly stacked without pressing the paste bump 14, a part of the paste bump 14 may protrude above the surface of the insulating layer 20, thereby making it difficult to sequentially stack the circuit pattern layer. .

After the paste bump 14 is pressed to flatten the surface of the insulating layer 20, the circuit pattern 12 is printed on the surface of the insulating layer 20 by an inkjet method as shown in FIG. 4E. . The printing process of the circuit pattern 12 is the same as in the first embodiment, whereby one circuit pattern layer is formed.

The circuit pattern 12 includes a land portion formed at a portion to which the paste bumps 24 for interlayer electrical conduction are to be coupled, and the circuit pattern is formed such that the land portion is formed at an appropriate position in consideration of the position where the paste bumps 24 are to be coupled in advance. Print (12).

Through this process, one circuit pattern layer is formed. The first circuit pattern layer is a state in which the circuit pattern 12 is printed on a flat surface consisting of an insulating layer 20 and an upper surface of the paste bump 14 for interlayer conduction.

In order to form a multi-layered circuit pattern, the paste bumps 24 are again bonded to predetermined positions of the first circuit pattern layer as shown in FIG. 4 (f), and the paste bumps 24 pass through as shown in FIG. The insulating layer 30 is laminated as much as possible, and the paste bumps 24 are pressed by the height of the insulating layer 30 to form a flat surface as shown in FIG. 4H, and then again as shown in FIG. 4I. The circuit pattern 22 is printed by the inkjet method.

This is equivalent to repeating the process of forming the first circuit pattern layer again, and thus, in forming the multilayer printed circuit board according to the present embodiment, the process described above as many as the number of circuit pattern layers required as shown in FIG. By repeating to produce a multilayer printed circuit board.

According to the present embodiment, when the circuit pattern layer of one layer is formed, the surface is formed of the circuit pattern 12, and electrical conduction between the circuit pattern layers is performed in the process of bonding the paste bumps 24 to the predetermined positions again. In order to implement, it is preferable to determine the bonding position of the paste bump 24 so that the land portion of the circuit pattern 12 is connected to the paste bump 24. As such, when the land portion of the circuit pattern 12 and the paste bump 24 are continuously connected in the vertical direction, a via hole penetrating the entire printed circuit board may be realized, such as a so-called 'stack via'.

When a plurality of circuit pattern layers are stacked by repeating the above-described process, a multilayer printed circuit board is formed by stacking copper foil plates 9 on the uppermost layer and compressing them collectively as shown in FIG. 4 (k). As described above, the copper foil plate 9 is etched to form an outer layer circuit 7 to complete the manufacture of the multilayer printed circuit board. In the multilayered printed circuit board according to the second embodiment, since the outer circuit 7 formed from the copper foil 9 is laminated on the outermost layer, the structural rigidity of the substrate as a whole is improved.

Although the technical spirit of the present invention has been described in detail with reference to the above-described embodiments, the above-described embodiments are for the purpose of description and not of limitation, and a person of ordinary skill in the art will appreciate It will be understood that various embodiments are possible within the scope.

As described above, according to the method of manufacturing a multilayer printed circuit board according to the preferred embodiment of the present invention, a plating process, a drilling process, and an etching process are unnecessary 'dry processes'. The board can be manufactured to be environmentally friendly and cost-effective.

In addition, due to the precision of inkjet printing technology, it is possible to realize highly integrated interconnection of printed circuit boards.

Claims (8)

(a) bonding the first paste bump to a predetermined position on the substrate; (b) depositing the first insulating layer on the substrate such that the first paste bump penetrates through the first insulating layer; (c) pressing the first paste bump in correspondence with the height of the first insulating layer; And (d) printing a first circuit pattern on the surface of the first insulating layer by an inkjet method. The method of claim 1, After step (d) (e) coupling a second paste bump to a predetermined position of the first circuit pattern; (f) stacking the second insulating layer on the first insulating layer such that the second paste bump penetrates through the second insulating layer; (g) pressing the second paste bump in correspondence with the height of the second insulating layer; And (h) printing a second circuit pattern on the surface of the second insulating layer by an inkjet method. The method of claim 2, The substrate is a multi-layer printed circuit board manufacturing method of a carrier metal layer in which the base pattern is laminated on the surface. The method of claim 3, The base pattern is formed by printing on the surface of the carrier metal layer by an inkjet method, the multilayer printed circuit board manufacturing method comprising a land portion corresponding to the position where the first paste bump is coupled. The method of claim 3, And removing the carrier metal layer from the printed circuit board after the step (h). The method of claim 3, The base pattern includes an electrode pattern, After the step (h) further comprises the step of perforating a cavity (cavity) in the carrier metal layer, by embedding an electronic device in the cavity to electrically connect the electrode of the electronic device with the electrode pattern Circuit board manufacturing method. The method of claim 2, The substrate is a copper foil, and after the step (h) further comprises the step of removing a portion of the copper plate to form an outer layer circuit. The method of claim 1, The first paste bump is exposed to the surface of the first insulating layer, a portion of the first circuit pattern is a method of manufacturing a multilayer printed circuit board electrically connected with the first paste bump.

Images