KR100330410B1 - Printed circuit board - Google Patents

Abstract

The present invention is to provide a printed circuit board for reducing the cost, narrowing the pattern of the printed circuit board, high density of the component mounting, miniaturization of the product when the circuit having different electrical characteristics are mixed with each other There is this.

According to the present invention, a printed circuit board including a component layer on which an electrical component is mounted and a solder layer on which a solder is performed, are inserted between the component layer, the solder layer, and the component layer and the solder layer. Provided is a multilayer printed circuit board comprising a plurality of inner layers each formed of a material having different electrical characteristics.

Description

Printed circuit board

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board (PCB), and more particularly, is designed to be suitable for the circuit operation characteristics by changing the material of the printed circuit board in consideration of the frequency and characteristics of the circuit operated in the circuit.

Printed circuit boards are required to have high density of conductor patterns for high integration of ICs and high density of surface mounting. As a result, printed circuit boards have been multilayered, and high density wiring has been realized by narrowing the conductor width and the conductor spacing. In particular, in the case of a computer or a mobile communication terminal, semiconductor devices are highly integrated due to the necessity of processing a large amount of information in a short time and the necessity of miniaturization. The development of innovative technologies such as multilayering, thinning of plated throughholes (Session), narrowing of high-density patterning, and complexing are underway.

In fact, in the case of QFP (Quad flat package), which is conventionally used as a surface mount package, the connection terminals (leads) are arranged in one row on the outer periphery of the package, thereby increasing the package size with increasing lead number. In order to prevent this, a connection terminal is formed by solder balls arranged in a grid on the back side of a package, and therefore, a ball grid array (BGA) that can be miniaturized and can be miniaturized is used. In addition, the build-up multilayer wiring board can significantly reduce the size of the printed circuit board by using a photosensitive insulating resin, and in the case of four layers, a lamination process is unnecessary and a via hole by a conventional drill is used. ) Can be collectively formed by the photo method, and has been put to practical use because it can shorten the time required for pattern design.

On the other hand, high frequency circuits and analog circuits, such as the internal and external noise (phenomena) phenomenon, due to the failure and malfunction between the components themselves and parts between each other and the development of technology for this. In particular, when selecting materials for printed circuit boards, measures should be taken to prevent noise in electronic circuits. For example, paper phenol (Paper Phenol, Paper Epoxy) is used for single layer printed circuit boards because it is suitable for high humidity conditions, and glass epoxy (Glass Epoxy, Glass Polymide, etc.) has excellent mechanical strength, impact strength, and interlayer adhesion strength. Therefore, the printed circuit board is used for products requiring high density of conductor patterns or multilayer printed circuit boards. Teflon is a low dielectric constant material and is used for high frequency circuits to determine the pattern width of printed circuit boards.

As described above, in the printed circuit board manufacturing industry, there is a demand for technological advances in materials selection and manufacturing methods of printed circuit boards according to the characteristics of electronic circuits. In particular, in manufacturing printed circuit boards having different dielectric constants according to electronic circuit characteristics, There is a need for a simple and cost-effective manufacturing method.

FIG. 1 is a flow chart schematically showing a manufacturing process of a conventional general multilayer printed circuit board (MLB).

First, an inner layer raw material (CCL: Copper Clad Laminate) is introduced (100), and after processing a reference hole (102), an inner layer circuit is formed (104).

Next, an inner layer inspection for detecting defects is carried out (106), a blackening treatment for increasing adhesion when the inner layer is laminated (108), and a lamination process of adhering the layers between the layers using epoxy resins. (110).

Afterwards, the reference hole is drilled (112), the hole (Hole) for processing the connection between the inner and outer layers (114), Desmear process (116) to remove the epoxy resin and foreign matter in the hole Is done.

Then, copper plating is performed on the entire original plate manufactured through the above process (118), and an external circuit is formed through exposure and development on the original plate where the plating process is completed (120), and only the external layer forming portion is plated selectively ( 122).

Next, an etching process to corrode the unnecessary copper on the plated disc (124), an outer layer inspection (126), and a solder mask (S / M) printing to protect the surface circuit from the external environment is performed. (128).

Subsequently, the disc is surface treated (130), the outer shape is processed into a desired shape (132), and an electrical test is performed to see whether the wiring formed through the process operates normally (134).

Then, the final inspection (136), the shipment inspection (138), the finished product is packaged, shipped.

On the other hand, when manufacturing a multilayer printed circuit board by the conventional method of manufacturing a printed circuit board described above, each layer on which a conductor pattern is formed is used as the same material.

The printed circuit board is formed by using a single material having a constant dielectric constant, and when used in a high frequency circuit, a material having a low dielectric constant is required. As such a material, Teflon resin is generally used. .

However, since Teflon resin is expensive, a conventional printed circuit board in a printed circuit board in which a high frequency circuit and a low frequency circuit are used in a mixed manner does not require unnecessary cost because Teflon resin is also used in a portion where a low frequency circuit is used. There is a problem that this goes in.

In addition, in a circuit in which a signal pattern width of a printed circuit board is determined according to a frequency characteristic, since a conventional printed circuit board is made of a single material having a constant dielectric constant, a high frequency circuit and a low frequency circuit are mixed. In the case of a general-purpose material, there are many limitations between the part of the printed circuit board and the part of the pattern, and the part of the pattern is narrow. In general, the whole of the material has a problem that it is difficult to increase the density and miniaturization.

In addition, due to the failure of a part of the board (Board), by re-manufacturing the entire printed circuit board, there is also a problem that causes a waste of manufacturing time and materials.

The present invention has been made to solve the problems of the prior art as described above, when a circuit having different electrical characteristics are mounted on a printed circuit board to reduce the unnecessary waste of expensive materials, narrow the gap of the conductor pattern The purpose is to provide a printed circuit board that can achieve high density, high density of component mounting, and miniaturization of a product.

1 is a flowchart illustrating a manufacturing procedure of a multilayer printed circuit board according to the related art.

2 is a structural diagram of a printed circuit board according to a first embodiment of the present invention;

3 is a structural diagram of a printed circuit board according to a second embodiment of the present invention.

According to the present invention for achieving the object as described above, in the printed circuit board comprising a component layer on which the electrical component is mounted and a solder layer on which the solder is performed, the component layer, the solder layer And a plurality of inner layers inserted between the component layer and the solder layer, each formed of a material having different electrical characteristics.

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

2 is a first embodiment showing a method of manufacturing a printed circuit board considering the dielectric constant. This is described as follows.

In the first embodiment, as a surface conductor layer of a printed circuit board, a component layer 200 in which actual components are mounted, an inner layer 204 for forming a power plane, and an inner conductor pattern, and a ground plane And another inner layer 208 that can form an inner conductor pattern and a surface conductor pattern layer of a printed circuit board printed on four layers of solder side 212 that can be soldered after the actual component is mounted. The circuit board was constructed. In addition, prepregs 202, 206, and 210 were used to bond the layers and the layers of the finished product of the inner layer circuit, and the layers were stacked 216 to be processed at the correct position. The work reference hole 214 is formed to fix it. Meanwhile, the component layer 200 uses a material having low dielectric constant, and the other three layers 204, 208, and 212 use a general-purpose material. Since the most common material having the low dielectric constant is Teflon resin, in the present embodiment, the component layer 200 is composed of Teflon resin, and as the general-purpose materials 204, 208, and 212, FR-4 (Flame) is used. retardant) was used.

When a high frequency circuit, an analog circuit, and a digital circuit are mixed with each other in the multilayer printed circuit board configured as described above, the high frequency circuit and the analog circuit are formed in the component layer 200 using a low dielectric constant material, and the other circuit is formed of a universal material. It is formed in the used layer (204, 208, 212).

Meanwhile, in the first embodiment, the printed circuit board is manufactured in four layers, but the present invention is not limited to only four layers, and it can be applied to all multilayer printed circuit boards and double-sided printed circuit boards composed of only component layers and solder layers. It is so natural. In addition, in the first embodiment, only the component layer 200 is manufactured using a low dielectric constant material. However, the component layer 200 is not limited to the component layer, and other layers 204 and 208 other than the component layer 200 may depend on the circuit configuration. , 212) may be manufactured using low dielectric constant materials, and further, each layer may be manufactured using various materials to suit the electrical characteristics of the circuit.

When the printed circuit board manufactured by the same method as the first embodiment is used when high frequency circuits and low frequency circuits are mixed with each other, the problem of unnecessary waste of low dielectric constant materials, which are expensive materials, is eliminated, thereby reducing costs and improving productivity. Can be designed.

3A and 3B illustrate a second embodiment of a method of manufacturing a printed circuit board considering the dielectric constant. This is described as follows.

In the second embodiment, the general-purpose materials 300 and 320, which are generally used, and the low dielectric constant materials 310 and 330 used in the high frequency circuit, which greatly affect the pattern width and thickness of the printed circuit board, are laterally joined. It is a printed circuit board. The general purpose materials 300 and 320 and the low dielectric constant materials 310 and 330 are bonded using prepreg, which is an epoxy resin, after molding. The above general-purpose materials and low dielectric constant materials were prepared using FR-4 and Teflon, respectively, as in the first embodiment. In addition, the circuit connection of each material used the jumper wire and the connector.

In the printed circuit board manufactured as described above, the high frequency circuit and the analog circuit are formed in portions 310 and 330 made of low dielectric constant material, and the other circuits are formed in portions 300 and 320 made of general purpose material. . Meanwhile, in the second embodiment, two different materials are bonded to each other to form a printed circuit board. However, the printed circuit board may be manufactured by joining various materials to suit the characteristics of the entire circuit.

Meanwhile, the manufacturing method of a printed circuit board manufactured by joining different materials laterally is applied not only when a high frequency circuit and a low frequency circuit are mixed, but also when a circuit in which a heating component is used and a general circuit are mixed. Can be.

The heat generating parts include a DC converter, a rectifier, and a transformer. In the past, the heating parts are designed to be well-ventilated and well-cooled, mainly on the outside of the board. It has been recognized. In order to overcome this, in FIG. 3A, the heating component may be formed at 310 and 330, and the general circuit may be formed at 300 and 320. At this time, the material on which the heating component is mounted should be a material having good fire resistance, durability, and thermal conductivity. Such materials having good fire resistance, heat resistance and thermal conductivity include phenol, epoxy melamine, silicone resin or Teflon and flexible substrates. Fluorocarbon resins. Printed circuit boards using such materials are already commercially available in the art, but the object of the present invention is not to invent a substrate having good fire resistance, heat resistance and thermal conductivity, but to horizontally combine the already commercially available. There is this.

In the printed circuit board manufactured by the method described in the second embodiment, as in the first embodiment, when a high frequency circuit and a low frequency circuit are used in combination with each other, or a circuit in which a heating component is used and a general circuit are mixed with each other. In the case of using a mixture of circuits with different electrical characteristics, such as when used in combination with the other, it is possible to reduce the unnecessary waste of expensive materials, compared to conventional printed circuit boards manufactured using a single material, and conductor patterns This makes it possible to narrow the size of the components, increase the density of component mounting, and reduce the size of the product.

On the other hand, when a low frequency circuit and a high frequency circuit are mixed and used on a printed circuit board according to the present invention, the most important consideration is to suppress noise generated in the circuit as much as possible. When different materials are joined to shield noise, the printed circuit board may be formed by plating each of the surfaces of the joined materials with gold, nickel, and copper, which are noise shielding materials. In addition, there is a method in which the bonded substrate itself is a flexible substrate formed of a noise shielding polyester resin, a fluoride resin, or the like.

On the other hand, the difference between the first embodiment and the second embodiment described above is that the first embodiment is used in a circuit in which a low frequency circuit and a high frequency circuit are mixed and connected to each other, and the second embodiment uses a low frequency circuit and a high frequency circuit. Even if they are mixed with each other, they are mainly used for connecting two circuits as circuit connecting devices such as jumper wires and connectors.

The printed circuit board according to the present invention is used when a circuit having different characteristics is used, such as a case where a high frequency circuit and a low frequency circuit are mixed with each other, and a circuit using a heating component and a general circuit are mixed. In this case, since unnecessary waste of expensive materials can be reduced, the cost reduction effect is large, and the narrowing of the printed circuit board pattern, the high density of component mounting, and the miniaturization of the product can be realized.

The technical spirit of the present invention has been described above with reference to the accompanying drawings, but this is by way of example only for describing the best embodiment of the present invention and not for limiting the present invention. In addition, it is obvious that any person skilled in the art can make various modifications and imitations without departing from the scope of the technical idea of the present invention.

Claims (2)

In a printed circuit board having a circuit pattern, It is made by transversely joining at least two of low frequency circuit materials, high frequency circuit materials, general-purpose materials made of FR-4, and low dielectric constant materials. Forming by plating one of the noise shielding material gold, nickel, copper on each of the joints of the plurality of materials bonded horizontally, or forming the bonded substrate itself of one of the noise shielding material polyester resin, fluorinated resin Printed circuit board, characterized in that. The method of claim 1, Among the materials joined horizontally, the material on which the heating component is mounted is Printed circuit board, characterized in that formed of phenol, epoxy, melamine, silicone resin, Teflon, polyester resin, fluoride resin