KR101088808B1 - Chip embedded printed circuit board and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a device embedded printed circuit board and a method of manufacturing the same. The present invention comprises the steps of: a) forming a first substrate having via holes and circuit patterns for upper and lower electrical conduction; b) forming a plating layer on a portion of the circuit pattern on which the device is to be disposed; c) attaching an element to the plating layer; And d) stacking a second substrate having a via hole, a circuit pattern, and a device accommodating part for accommodating the device on the first substrate. According to the present invention, by attaching an element after circuit formation, the precision can be improved, and the micro circuit can be easily implemented, and various size components can be inserted into the printed circuit board.

PCB, embedded circuit board, embedded PCB

Description

Chip embedded printed circuit board and manufacturing method thereof

The present invention relates to a device embedded printed circuit board and a method of manufacturing the same. More specifically, the present invention relates to a device-embedded printed circuit board and a method of manufacturing the same, which reduce the amount of solder required to a part to which the device is attached, while preventing the bonding force between the solder and the circuit from being lowered.

In general, a PCB (Printed Circuit Board) mounts a variety of components on a flat plate made of phenol or epoxy resin, and the circuits connecting each component are concentrated on the surface of the resin flat plate. The circuit board is shortened and fixed. In the past, circuits were used to connect components by using wires. However, in this case, there is a fear of incorrect connection of the wiring or short circuit in the soldering process. Therefore, a PCB having high reliability by constructing a metal circuit on the foundation has been replaced.

PCBs are the core components of all electronic products, from home appliances to advanced computers, communications, industrial and military equipment. Therefore, according to the equipment used, the design circuit and manufacturing method are produced in small quantities and many kinds of different, and the production process is complicated and requires high technology. In addition, the scope of use is very diverse, and the speed of technological development of products using the same is a typical device industry, but it is an industry that requires technology and funding ability to respond quickly to technological change.

Since PCB plays a role of mounting and fixing various components such as semiconductor and passive components on the surface, high mechanical strength is required. That is, when the component is mounted, the PCB should not be broken or the circuit will be disconnected. In addition, even if there is no physical damage, heat generation and impedance problems due to component operation must be solved. In recent years, the durability of various phenomena that is required as the operation speed of the component increases.

On the other hand, due to the light and small size of electronic products, miniaturization and weight reduction of related components are intensified. Accordingly, in addition to the method of miniaturizing and lightweighting each component individually, various components can be integrated into one module. Technology to embed passive elements such as resistors (R), capacitors (C), inductors (L), etc. in a multi-layered printed circuit board to improve the mounting density. Is being studied.

Such embedded printed circuit boards may be classified into two types, a foamed type and an inserted type. Form type printed circuit board refers to a technology of replacing a conventional chip capacitor, resistor, and inductor by inserting a material that functions as a capacitor, a resistor, and an inductor into the board. A capacitor-embedded printed circuit board, if integrated in one part, or a resistor-embedded printed circuit board, if a resistor is integrated as part of a printed circuit board.

This form-type printed circuit board has the effect of reducing the size of the board by more than 40% compared to the existing by incorporating a capacitor that occupies about 60% of the passive elements, and improves electrical characteristics due to low impedance at high frequencies. Can come. However, this foam type has a narrow application range because no high-capacity material has been developed compared to the general mounting parts, and thus only a small number of passive elements are actually built. In this case, each individual part has a lack of technical, productive and performance advantages. Insert type printed circuit boards that are directly embedded in a substrate have been developed.

Insert-type embedded PCBs are called active element insert embedded PCBs when active devices are embedded directly on printed circuit boards, and passive element insert embedded PCBs when passive devices are directly embedded on printed circuit boards.

The individual element printed circuit board according to the prior art includes a chip first process in which a chip is first embedded in the substrate and connected to the substrate, and a chip last process in which the chip is connected to the substrate and later embedded in the substrate. In other words, the chip first process is to place a chip on a face-up and to make a multilayer printed circuit board on top of the chip, and then to embed the chip into the substrate, and the chip last process is to make a multilayer printed circuit board and then to the inside or top layer of the printed circuit board. The chip is face-down in the cavity formed in the embedded circuit board.

The above methods use adhesive tape as a material for attaching the chip. The method of using adhesive tape is a method of connecting the chip and the substrate after attaching and attaching the chip in the cavity with the adhesive tape. Because of the process, the process is long. In addition, since a process for electrically connecting the chip is required, chip damage and tolerance may occur.

An object of the present invention is to provide a device-embedded printed circuit board and a method of manufacturing a device-embedded printed circuit board to form a plating layer on a portion to which the device is attached to prevent damage to the circuit and to improve the bonding strength of the solder.

The present invention to achieve the above object is a) forming a first substrate having a via hole and a circuit pattern; b) forming a plating layer on a portion of the circuit pattern on which the device is to be disposed; c) attaching an element to the plating layer; And d) stacking a second substrate having a via hole, a circuit pattern, and a device accommodating part for accommodating the device on the first substrate.

The device accommodating part may be formed through the second substrate, and the method may further include e) stacking a third substrate having a via hole and a circuit pattern on the second substrate after the step d). have.

The method may further include disposing prepregs between the substrates and the substrates, and thermally compressing the stacked substrates.

In addition, in step b), a plating layer may be formed by plating one or two or more conductive metals selected from gold, silver, copper, nickel, tin, and cobalt.

In addition, the step c) is characterized in that to attach the device to the plating layer using a lead-free solder or conductive paste.

In addition, an oxide treatment may be further included between the step b) and the step c).

On the other hand, the present invention is a first substrate having a via hole and a circuit pattern; A plating layer formed on a portion of the circuit pattern to which the device is attached; An element attached to the plating layer; And a second substrate which is provided with a via hole, a circuit pattern, and an element accommodating part for accommodating the element, and which is pressed against the first substrate.

The device accommodating part may further include a third substrate formed through the second substrate, stacked on the second substrate, and having a via hole and a circuit pattern.

In addition, the device receiving portion may be formed in the form of a groove in which the opposite side of the inlet is closed.

In addition, a prepreg may be inserted between the substrates and the substrates.

In addition, the plating layer may be made of any one or two or more conductive metals selected from gold, silver, copper, nickel, tin, and cobalt.

In addition, the device is characterized in that attached to the plating layer by a lead-free solder or conductive paste.

In addition, the first substrate on which the plating layer is formed is characterized in that the oxide treatment.

According to the present invention, by attaching an element after circuit formation, the precision can be improved, and the micro circuit can be easily implemented, and various size components can be inserted into the printed circuit board. In addition, there is an advantage that it is environmentally friendly because it does not use lead, which is an environmental regulation material.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, detailed description is abbreviate | omitted when it is judged that it may obscure the summary of this invention. In addition, preferred embodiments of the present invention will be described below, but the technical idea of the present invention may be implemented by those skilled in the art without being limited or limited thereto.

1 is a flowchart illustrating a manufacturing process of a device embedded printed circuit board according to a preferred embodiment of the present invention, FIG. 2 is a cross-sectional view of a device embedded printed circuit board according to a preferred embodiment of the present invention, and FIG. 4 is a view showing a manufacturing process of the first substrate, Figure 4 is a view showing a manufacturing process of the second substrate of FIG.

Hereinafter, a device embedded printed circuit board 100 and a method of manufacturing the same will be described with reference to FIGS. 1 to 4.

The device-embedded printed circuit board 100 according to the preferred embodiment of the present invention is a device of the first substrate 110 and the circuit pattern 116 having the via hole 112 and the circuit pattern 116 for the electrical conduction of the upper and lower surfaces. A plating layer 120 formed on a portion to which the 140 is to be attached, an element 140 attached to the plating layer 120, and a via hole 152, a circuit pattern 158, and the element 140 for electrical conduction of upper and lower surfaces thereof. An element accommodating part 156 for accommodating the second substrate 150 may be pressed against the first substrate 110. Here, a prepreg 170 may be further inserted between the first substrate 110 and the second substrate 150 to improve adhesion between the substrates 110 and 150.

In order to manufacture the device-embedded printed circuit board 100, first, a first substrate 110 having a via hole 112 and a circuit pattern 116 is formed (S100).

The via hole 112 formed in the first substrate 110 is for electric conduction on the upper and lower surfaces of the first substrate 110. The via hole 112 may be formed by drilling. A drilling machine such as a CNC (Computer Numerical Control) drill or a laser drill may be used. Can be drilled.

In this state, the first substrate 110 is generally composed of phenol or epoxy, which is an insulator mainly used as a substrate of the substrate, so that the circuit is not connected. Only the space for the interlayer connection through the via hole 112 is provided. It is secured. Therefore, plating of conductive metal or metal foil is performed on the surface of the first substrate 110 on which the via holes 112 are formed and on the inside of the via holes 112 to perform preliminary work for connecting the circuits. At this time, it is advantageous to use copper as the conductive metal or metal foil used for plating the first substrate 110 in consideration of electrical conductivity and cost.

The first substrate 110, in which plating or metal foil is laminated with a conductive metal, forms a circuit pattern 116 through a corrosion process.

For example, in the first substrate on which copper foil is laminated, the circuit pattern 116 may be formed through a lamination-exposure-development process of a dry film.

That is, after laminating the dry film to the first substrate 110 on which copper foil is laminated, an exposure and development process is performed using an artwork film on which the form of the circuit pattern 116 is output. .

For reference, exposure is a process of contacting the artwork film to the first substrate 110 on which the dry film is laminated, and then irradiating ultraviolet light so that the photosensitive material reacts to light. It is a process of removal.

After the development process, the dry film remaining in the portion where wiring is required serves as an etching resist, which allows only the copper foil of the portion where the wiring is not formed during corrosion. The circuit pattern 116 can be formed by removing the dry film remaining after the copper foil of the portion not forming the circuit is corroded.

In the circuit pattern 116 formed as described above, a plating layer 120 is formed on a portion where the device 140 is to be disposed (S110).

If the amount of solder used in the soldering process to attach the device 140 to the circuit pattern 116 is excessive, the tension is too high, which may cause cracks in the circuit. There is a problem that the bonding force is lowered.

In order to solve the above problems, in the present embodiment, the plating layer 120 may include any one or two or more conductive metals selected from gold, silver, tin, copper, nickel, and cobalt having excellent bonding strength with solder. The device 140 is formed by plating on the portion to be attached. By doing so, even if the size of the plating layer 120 is reduced, the bonding force with the solder can be improved and the amount of solder used can be reduced. Among them, gold, silver, and tin are particularly excellent in bonding strength with solder and have an advantage of showing improved solderability when plated on a heat-resistant film.

After the plating layer 120 is formed as described above, the first substrate 110 is treated with an oxide 130 (S120). In this case, the plating layer 120 serves to prevent the portion to which the device 140 is attached is oxidized when the oxide 130 of the first substrate 110 is processed.

The first substrate 110 and the second substrate 150, which will be described later, are treated with oxides 130 and 160, and thus the adhesion and heat resistance between the substrates 110 and 150 can be improved through the oxide 130 and 160 treatment.

The material used for the oxide treatment is not particularly limited, but the oxide treatment may be performed using any one of brown oxide and black oxide.

Note that the oxide process is to impart a roughness by oxidizing the surface of the copper foil by chemical methods specifically sikineunde subjected to a blackening treatment to deposit a Cu ₂ O or CuO on the surface of the copper foil Cu ₂ O is because assuming its brown brown oxide La CuO is black, so it is called black oxide.

While black oxide has good stability in mass production and excellent adhesion strength and heat resistance, the oxide film of the inner layer formed by blackening treatment is reduced by being penetrated by acid component during the desmear and copper plating process, so that the copper foil of the inner wall of the hole turns pink. The disadvantage is that rings are likely to occur.

In comparison, brown oxide is more resistant to pink rings, but the adhesive strength is weaker than black oxide. Nevertheless, there is an advantage that there is little change such as a decrease in the roughness of the copper foil surface after the treatment.

After the oxide treatment is performed as described above, the device 140 is attached to the plating layer 120 (S130).

At this time, the attachment of the device 140 may use a conductive paste such as lead-free solder or silver paste, copper paste, tin-copper paste, including any one metal selected from tin, silver, copper, bismuth, and indium.

These lead-free solders and conductive pastes do not contain lead and are generally made of lead, which is a soldering member that can replace soldering members, such as solder paste and solder cream, which are environmentally regulated.

After attaching the device 140, an oxide film or an organic material may be generated during the drying process of the first substrate 110 to which the device 140 is attached. In order to remove the oxide layer and the organic material, a surface treatment process is performed on the first substrate 110 (S140).

The surface treatment may be performed through a plasma surface treatment process. The surface treatment may remove the oxide film and the organic material generated on the first substrate 110 and the device 140 and the solder joint, and the low temperature of the plasma. Due to the characteristics, there is an advantage that the quality of the product can be improved without causing thermal deformation to the first substrate 110 and the device 140.

After attaching the device 140 to the first substrate 110, as shown in FIG. 4, the via hole 152, the circuit pattern 158, and the device 140 for accommodating the upper and lower surfaces may be accommodated. The second substrate 150 including the formed element accommodating part 156 is stacked on the first substrate 110 (S150).

The via hole 152, the circuit pattern 158, and the oxide 160 formed on the second substrate 150 may be formed in the same manner as the process of forming the first substrate 110.

The element accommodating part 156 provided in the second substrate 150 is to embed the element 140 between the first substrate 110 and the second substrate 150 and may surround the element 140. So that the opposite side of the inlet is formed in the form of a closed groove.

When the second substrate 150 is stacked on the first substrate 110, a prepreg 170 is disposed between the first substrate 110 and the second substrate 150 to improve adhesion between the substrates to integrate the respective substrates. And thermal compression using a heat press. Press lamination processes can be used for this thermal compression.

In order to completely cure the prepreg during thermal compression, the substrate should be compressed for 20 to 25 minutes at 170 to 175 ° C. When pressure is applied, the maximum pressure is initially applied, which causes distortion due to stress. Therefore, the thermocompression process is performed by keeping the pressure low for the first 5 to 10 minutes and then applying the maximum pressure.

5 is a flowchart illustrating a manufacturing process of an element embedded printed circuit board according to another embodiment of the present invention, FIG. 6 is a cross-sectional view of an element embedded printed circuit board according to another embodiment of the present invention, and FIG. 8 is a view illustrating a manufacturing process of the first substrate, FIG. 8 is a view showing a manufacturing process of the second substrate of FIG. 6, and FIG. 9 is a view showing a manufacturing process of the third substrate of FIG. 6.

Hereinafter, a device-embedded printed circuit board 200 and a method of manufacturing the same will be described with reference to FIGS. 5 to 9.

The device-embedded printed circuit board 200 according to another embodiment of the present invention is a device of the first substrate 210 and the circuit pattern 216 having a via hole 212 and a circuit pattern 216 for upper and lower electrical conduction. A plating layer 220 formed on a portion to which the 240 is to be attached, an element 240 attached to the plating layer 220, a via hole 252, a circuit pattern 258, and the device 240 for electrical conduction of upper and lower surfaces. A device accommodating part 256 is formed to penetrate up and down for accommodating, and is stacked on the second substrate 250 and the second substrate 250 that are pressed onto the first substrate 210, and the electrical conduction of the upper and lower surfaces is applied. And a third substrate 270 having a via hole 272 and a circuit pattern 276. Preferably, a prepreg 290 is inserted between the substrates 210, 250, and 270 to improve adhesion between the substrates 210, 250, and 270.

First, the first substrate 210 provided in the device-embedded printed circuit board 200 according to another embodiment of the present invention includes a via hole 212 and a circuit pattern 216 (S200) and a circuit pattern 216. The plating layer 220 is formed in the portion where the device 240 is disposed (S210). After performing the oxide treatment (S220) and then lead-free soldering the device 240 on the plating layer 220 (S230). After attaching the device 240 to the first substrate 210, plasma surface treatment is performed to remove the oxide film and the organic material of the first substrate 210, the device 240, and the solder joint (S240).

In this case, the process of forming the first substrate 210 as described above is the same as forming the first substrate 110 in the above-described preferred embodiment of the present invention, a detailed description thereof will be omitted.

The second substrate 250 including the via hole 252, the element accommodating part 256, and the circuit pattern 258 is stacked on the first substrate 210 formed as described above (S250).

Here, the via hole 252 and the circuit pattern 258 provided in the second substrate 250 may be formed in the same manner as the via hole 212 and the circuit pattern 216 of the first substrate 210 and the oxide 260. ) Process may also be performed in the same manner as in the case of the first substrate (210).

The element accommodating part 256 provided on the second substrate 250 is disposed at a portion corresponding to the position of the element 240, and the second substrate 250 passes through the upper and lower surfaces of the second substrate 250. Perforations). The second substrate 250 thus formed is stacked on the first substrate 210 such that the device 240 is inserted into the device accommodating part 256.

9, the second substrate 250 includes a via hole 272 and a circuit pattern 276, as shown in FIG. 9, and further stacks a third substrate 270 processed with an oxide 280 (S260). ).

The formation of the via hole 272, the circuit pattern 276 and the process of the oxide 280 provided in the third substrate 270 are the same as those of the first substrate 210 or the second substrate 250 described above. Can be formed.

The third substrate 270 is stacked on the second substrate 250 to cover the device 240 so that the device 240 is embedded in the device embedded printed circuit board 200.

The stacked substrates 210, 250, and 270 are integrated by thermal compression using a heat press (S270). In this case, the prepreg 290 may be disposed between the substrates 210, 250 and 270, and then thermally compressed through a press lamination process to further improve the adhesive force between the substrates 210, 250 and 270.

Although not shown, in the device-embedded printed circuit board 100 and 200 manufactured as described above according to an embodiment of the present invention, an interstitial via hole (IVH) is formed as necessary to implement electrical connection between circuits of the stacked substrate.

The above description is merely illustrative of the technical idea of the present invention, and various modifications, changes, and substitutions may be made by those skilled in the art without departing from the essential characteristics of the present invention. will be. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by the embodiments and the accompanying drawings. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents thereof should be construed as being included in the scope of the present invention.

1 is a flow chart showing a manufacturing process of a device-embedded printed circuit board according to a preferred embodiment of the present invention.

2 is a cross-sectional view of a device-embedded printed circuit board according to a preferred embodiment of the present invention.

3 is a view illustrating a manufacturing process of the first substrate of FIG. 2.

4 is a view illustrating a manufacturing process of the second substrate of FIG. 2.

5 is a flowchart illustrating a manufacturing process of an element embedded printed circuit board according to another exemplary embodiment of the present invention.

6 is a cross-sectional view of a device-embedded printed circuit board according to another exemplary embodiment of the present invention.

FIG. 7 is a view illustrating a manufacturing process of the first substrate of FIG. 6.

8 is a view illustrating a manufacturing process of the second substrate of FIG. 6.

9 is a view illustrating a manufacturing process of the third substrate of FIG. 6.

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

100,200: Embedded PCB

110,210: first substrate 120,220: plating layer

140,240: device 156,256: device housing

150,250: second substrate 270: third substrate

Claims (13)

a) forming a first substrate having via holes and circuit patterns; b) plating one or two or more metals selected from gold, silver and tin on a portion of the circuit pattern on which the device is to be formed to form a plating layer; c) attaching the device to the plating layer by using a lead-free solder containing any one metal selected from tin, silver, copper, bismuth and indium, or using a conductive paste of any one of silver paste, copper paste and tin paste. Doing; d) performing plasma surface treatment on the first substrate to which the device is attached; And and e) stacking a second substrate having a via hole, a circuit pattern, and a device accommodating portion for accommodating the device on the first substrate. The method of claim 1, The device accommodating portion is formed through the second substrate, To step after step e) above. f) stacking a third substrate having via holes and a circuit pattern on the second substrate. The method according to claim 1 or 2, And arranging prepregs between the substrates and the substrates, and thermally compressing the stacked substrates. delete delete The method of claim 1, Between step b) and step c) Oxide treatment of the first substrate on which the plating layer is formed, characterized in that it further comprises a device embedded printed circuit board. A first substrate having a via hole and a circuit pattern; A plating layer formed by plating any one or two or more metals selected from gold, silver and tin on a portion of the circuit pattern to which an element is attached; An element attached to the plating layer by using a lead-free solder containing any one metal selected from tin, silver, copper, bismuth, and indium, or using a conductive paste of any one of silver paste, copper paste, and tin paste; And A second substrate including a via hole, a circuit pattern, and an element accommodating part for accommodating the element, and being compressed onto the first substrate, And the first substrate on which the device is attached is subjected to plasma surface treatment. The method of claim 7, wherein The device accommodating portion is formed through the second substrate, And a third substrate stacked on the second substrate and having a via hole and a circuit pattern. The method of claim 7, wherein The element accommodating part is a printed circuit board, characterized in that the opposite side of the inlet is formed in the form of a groove. 9. The method according to claim 7 or 8, And a prepreg inserted between the substrates and the substrates. delete delete The method of claim 7, wherein The first substrate on which the plating layer is formed is an element embedded printed circuit board, characterized in that the oxide treatment.

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