KR100498974B1 - Package prevented from the EMC flowing into via hole during the PCB fabricating process and the manufacturing method thereof - Google Patents

Abstract

The present invention relates to a package using a printed circuit board (PCB) and a manufacturing method thereof. More specifically, the present invention relates to a package manufacturing method for performing data transmission in an IrDA (Infrared Data Association) method.

At the end of the manufacturing process of the printed circuit board, the EMC is molded to protect the package. Conventionally, the EMC cannot fill the via hole because EMC cannot penetrate the via hole and the ink filled in the via hole is filled, so that the EMC fills the via hole. There was a problem that the via hole does not function as a contact with the motherboard.

According to the present invention, after the drilling process after the ink filling, the plating layer is formed to prevent EMC penetration by the plating layer.

Description

Package prevented from the EMC flowing into via hole during the PCB fabricating process and the manufacturing method

The present invention relates to a package using a printed circuit board and a method of manufacturing the same. More specifically, in the process of molding an EMC on a printed circuit board, a package of the latter half of the printed circuit board package manufacturing process that performs IrDA-type data communication, the printed circuit board due to the pressure during EMC molding This is to prevent the phenomenon that EMC penetrates the via hole of and prevents the via hole from functioning as a contact.

In the future, the package applied to electronic products will be systemized by itself, and the size and weight will be innovatively lowered and functions will be improved. As a result, councils such as Bluetooth and IrDA have been formed, and a market is forming.

The present invention relates to a package for IrDA.

The Infrared Data Association (IrDA), as it is known, originally means an association formed in 1993 as an industry-sponsored organization to create international standards for hardware and software used in infrared communication links, but currently generally Refers to the short-range communication method by the infrared data communication, it is also used as the latter meaning of this specification.

In infrared communication, a special form of radio transmission, the collected rays in the infrared frequency spectrum, measured in terahertz or trillion hertz, are modulated into information and sent to a receiver within a relatively short distance from the transmitter. Infrared radiation is the same technology used to control a TV with a remote control.

Infrared data communication has played an important role in wireless data communication with the popularity of notebook computers, PDAs, digital cameras, mobile phones, pagers, and the like. Existing or new possibilities include:

i) Send the document from the notebook computer to the printer.

ii) Exchange business cards using a pocket PC.

iii) Set up the same schedule or phone book between desktop and notebook computers.

iv) Send a fax to a remote fax machine using a public telephone on a laptop computer.

v) The digital camera sends the image to the computer as a ray.

In the future, the package applied to electronic products is going from a single chip package to a multichip package or modularization.

The most common and efficient package utilizing printed circuit boards is a so-called area array (CSP) or ball grid array (BGA) that uses a solder ball to connect the package to the motherboard. There is. This is a package that can maximize the number of pins per unit area, and has been evaluated as the most common and efficient package since the 1990s.

However, in a short distance wireless communication network (Bluetooth, IrDA, etc.), a so-called periphery lead frame method that connects a printed circuit board and a motherboard using a lead wire outside the package is generally used, not a CSP or BGA method. .

The reason for this is explained with the example of IrDA to which this invention is applied as follows. As is known, IrDA is a signal transmission method using infrared rays, and the communication distance is short, and the device can communicate only with devices within about 30 degrees in terms of transmitting infrared rays. That is, data communication cannot be performed with devices that are out of the communication direction.

Due to these IrDA circuit characteristics, printed circuit board packages mounted on the motherboard must also have a general direction for signal transmission. That is, the devices in charge of infrared transmission / reception should be directed toward other devices that transmit and receive data communication, and thus other devices should be directed in a specific direction. Therefore, elements are mounted on the IrDA circuit board in an upright position.

However, in the BGA mounting method, since the packages are mounted in a laid-down form and thus the packages cannot be directional, the lead frame method has been used in spite of the disadvantage that conventional multilayering is impossible in the IrDA substrate.

The present invention can be applied not only to IrDA packages but also to all cases in which the lead frame method is inevitably used in connection between the package and the motherboard due to structural and manufacturing constraints.

In order to replace the lead frame mounting method in the IrDA package or other package using the lead frame mounting method, the signal transmission must be performed by the so-called blind via hole instead of the lead frame between the package and the motherboard.

2, there is shown a cross section of a printed circuit board 20 made according to the method of the present invention. Here, the blind via hole 21 formed by the method described below not only serves to electrically connect the upper and lower surfaces of the printed circuit board, but also serves as an electrical contact between the motherboard and the printed circuit board as described above.

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 most commonly used substrate as a double-sided printed circuit board is a copper clad laminate (CCL) coated with thin copper plating on both sides of an insulator.

In double-sided printed circuit boards or MLBs, electrical signals are exchanged through via holes between the top and bottom surfaces.

The via hole is formed by processing a disc by drilling or the like. The via wall surface of the via hole is copper plated to have conductivity, and the inside of the via hole is filled with insulating ink.

In general printed circuit boards, these via holes only serve to electrically connect the upper and lower surfaces as described above, but as described above, in the IrDA substrate, in addition to the general through holes, blind via holes are used to replace lead frames for connection between the package and the motherboard. The blind via hole serves as a contact point with the motherboard (or main board) on which the printed circuit board is to be mounted.

2 is an example having a blind via hole 21 which serves to connect the upper and lower surfaces of the printed circuit board used in the package mounting method for IrDA manufactured according to the present invention, and to connect the printed circuit board and the motherboard. A cross-sectional view of a typical printed circuit board 20 is shown.

FIG. 3 is a diagram of a MiniSIR2-2 module, which is a package for the IrDA 1.0 standard, manufactured by NOVALOG (located in Costa Mesa, Calif.), As an example of an IrDA package. MiniSIR2-2 is a trade name of NOVALOG manufactured to the IrDA 1.0 standard, and is itself composed of one module. In other words, the MiniSIR2 contains a PCB, an IC chip, and various passive components. All of these are put together by molding. Among them, a part corresponding to the PCB may be applied in the present invention.

In the front, top and bottom views of Fig. 3, unlike the general package, the molded parts like camel rods (or domes) (indicated by "Emitting Center" and "Light Receiving Center" in the front view) Part, which corresponds to the infrared transmitter / receiver. That is, the part molded in the form of a camel rod should be installed so as to face the device that should be actually operated in the wireless local area communication to remove the noise due to the interference effect as much as possible. Therefore, as described above, in the IrDA printed circuit board, the mounting method should be a vertical mounting type. In other words, unlike a typical BGA mounting method, the package is configured to be mounted upright.

FIG. 4 illustrates a process of forming a blind via hole for electrical connection with a motherboard in a method of manufacturing a printed circuit board according to the related art.

In (A), a printed circuit board is shown in which blind via holes are formed. Reference numeral 41 denotes a printed circuit board in which via holes are formed in accordance with a circuit pattern and then via holes are formed by drilling or the like. Reference numeral 42 is a part covered with copper that serves as a conductive wire through which current in the circuit flows. The solder resist 43 is applied to the printed circuit board 41 on which the via holes are formed.

(B) covers the artwork film 44 in which the circuit pattern was printed on the printed circuit board to which the soldering resist 43 was apply | coated.

Then, ultraviolet rays are irradiated to develop the solder resist. In the black part of the artwork film, ultraviolet rays do not pass through, so that the solder resist remains, and ultraviolet rays pass through only the transparent part, so that the solder resist is developed, that is, cured.

In (C), the state in which the solder resist was developed and the blind via hole 45 was formed is shown.

Here, EMC 46 molding is applied on top for package circuit protection.

In (D), the state which performed EMC molding by the conventional method is shown. It was not able to withstand the pressure during EMC molding, so the solder resist on the blind side of the blind via hole was recessed and the EMC flowed through the via hole.

Via holes that flow down the EMC and cover the via hole hole walls cannot act as contacts with the motherboard.

Because of this problem, in the conventional method, the via hole portion is designed to be disposed outside the circuit, and the EMC molding is not applied to the portion. However, in this case, the package becomes large and package protection is not properly performed.

As described above, at the end of the manufacturing process of the printed circuit board for IrDA, the EMC is molded to protect the package. In the past, EMC cannot penetrate the via hole and the ink filled in the via hole is depressed due to the pressure during the EMC molding process. As a result, EMC filled the via holes so that the via holes could not function as contacts with the motherboard.

An object of the present invention is to provide a method for preventing such intrusion into a via hole of EMC and a printed circuit board manufactured according to the method.

According to the present invention, there is provided a method of manufacturing a package in which an epoxy mold compound (EMC) does not enter into a via hole, the method comprising: processing a through hole in a printed circuit board (original plate); Copper plating the printed circuit board; Filling an insulator in the through hole; Forming a blind via hole by removing the filled insulator from a lower surface of the printed circuit board in an upward direction; Plating the printed circuit board to form a conductive layer on an entire surface of the printed circuit board and an inner wall of the blind via hole; Forming a circuit pattern designed on the printed circuit board; Applying a solder resist to a portion of the printed circuit board that does not need to be connected to another substrate or element; Plating Ni and Au on portions of the printed circuit board that are connected to other substrates or devices; And molding the EMC on the printed circuit board.

The printed circuit board which EMC does not penetrate into the via hole according to the present invention is formed by blocking one side of the through hole with an insulating ink layer, a copper plating layer, and a solder resist, and the inner wall is copper plated, and serves as a contact point with another substrate or motherboard. A substrate on which via holes are formed; And an EMC layer molded to cover the circuit pattern and the via hole formed on the substrate.

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

2, there is shown a cross section of a printed circuit board 20 produced by the method according to the invention.

5A and 5B illustrate a method of manufacturing a printed circuit board having a contact between a motherboard and a printed circuit board and a blind via hole serving as a contact between a top surface and a bottom surface of the printed circuit board according to the method of the present invention. The cross section of the printed circuit board is shown.

In (A), through-holes are formed in the copper-clad laminate 50 by a drilling method. Reference numeral 51 is a copper foil layer, and 52 is an insulating layer.

In (B), copper plating 53 is performed on the substrate to form a conductive layer on the substrate surface and inside the through hole.

In (C), the inside of the through hole is filled with insulating material 54.

In (D), the blind via hole 55 is formed by laser drilling from the lower surface of the printed circuit board to the upper surface direction.

In (E), the plating layer 56 is formed on the inner wall of the blind via hole by copper plating the entire substrate.

Then, according to a known method, a circuit pattern is formed on the printed circuit board with the conductive layer exposed.

The method of forming a circuit pattern is as follows. When the dry film is adhered and the artwork film printed with the circuit pattern designed thereon is applied to the ultraviolet ray and irradiated with ultraviolet rays, the dry film of the portion irradiated with ultraviolet rays is cured, and the portion not irradiated with ultraviolet rays remains. Etching here leaves the cured dry film intact, and the uncured dry film and its conductive layers are removed. The removal of the dry film layer cured using the peeling solution here forms a circuit pattern in which the conductive portion of the designed circuit is exposed.

In addition to the above-described circuit pattern forming method, any circuit pattern forming method may be used.

In (F), the solder resist 57 is applied to the portion of the printed circuit board on which the circuit pattern is formed so as not to be connected with other substrates or elements to prevent unwanted connection. Then, Ni and Au layers 58 are plated to prevent contact failures at portions connected with other substrates or elements.

In (G), as compared with FIG. 4D, the EMC 59 is molded for circuit protection on a substrate completed by Ni and Au plating. A strong pressure is applied to the molding process, but the blind via hole 55 does not penetrate the EMC due to the insulating layer and the copper plating layer supporting it.

Conventionally, only a package for a lead frame mounting method may be used when manufacturing an IrDA package, but according to the method of the present invention, an IrDA package may be manufactured using a printed circuit board using blind via holes.

As a result, it is possible to overcome the limitation of the single-layer circuit, which is the limitation of the package for the lead frame type mounting method, and to form a double-sided printed circuit board or a multilayer printed circuit board meeting the recent miniaturization and complexity of the IrDA package.

In addition, unlike the case in which the blind via hole serving as a contact point of the conventional printed circuit board is disposed outside the package, the blind via hole may not be subjected to EMC treatment, thereby miniaturizing the package and sufficiently protecting the via hole during EMC molding.

Although the present invention has been described above, the description is not intended to limit the scope of the present invention, and those skilled in the art may add various modifications thereto within the scope of the present invention, and the scope of the present invention is limited only through the interpretation of the following claims. It will be.

1 is a cross-sectional view of a structure in which a printed circuit board package is mounted on a motherboard according to a conventional general BGA method.

Figure 2 is an exemplary embodiment having a blind via hole that serves to connect the upper and lower surfaces of the printed circuit board used in the package mounting method for IrDA manufactured in accordance with the method of the present invention and to connect the printed circuit board and the motherboard Cross section of a printed circuit board.

Figure 3 shows a MiniSIR2 module for IrDA 1.0 standard manufactured by NOVALOG.

4 is a step-by-step view showing a state of a via hole during formation of a blind via hole in a process of manufacturing a printed circuit board according to a conventional method.

5A and 5B are diagrams for explaining a method for forming blind via holes according to the method of manufacturing a printed circuit board of the present invention.

Claims (7)

Processing a through hole in a printed circuit board (original plate); Copper plating the printed circuit board; Filling an insulator in the through hole; Forming a blind via hole by removing the filled insulator from a lower surface of the printed circuit board in an upward direction; Plating the printed circuit board to form a conductive layer on an entire surface of the printed circuit board and an inner wall of the blind via hole; Forming a circuit pattern designed on the printed circuit board; Applying a solder resist to a portion of the printed circuit board that does not need to be connected to another substrate or element; Plating Ni and Au on portions of the printed circuit board that are connected to other substrates or devices; And Molding an EMC on the printed circuit board; Package manufacturing method that does not penetrate the EMC (Epoxy Mold Compound) in the via hole, characterized in that it comprises a. The method of claim 1, wherein the original plate is a copper clad laminate (CCL). The method of claim 1, wherein the conductive material is copper. delete The method of claim 1, wherein the blind via hole is used as a contact point between a package utilizing the printed circuit board and a motherboard on which the package is to be mounted. The method of claim 1, wherein the package utilizing the printed circuit board is used for a package for performing an Infrared Data Association (IrDA) data communication method. A substrate formed by covering one side of the through hole with an insulating ink layer, a copper plating layer, and a solder resist, and having an inner wall copper plated thereon and a via hole serving as a contact with another substrate or motherboard; And 2. The printed circuit board of which EMC does not intrude into a via hole including a circuit pattern formed on the substrate and an EMC layer molded to cover the via hole.