KR102494336B1 - Printed circuit board and method for manufacturing the same - Google Patents

Abstract

A printed circuit board according to an embodiment of the present invention includes a core, and the core includes a first metal layer; and a heat dissipation metal formed in the first metal layer.

Description

Printed circuit board and its manufacturing method {PRINTED CIRCUIT BOARD AND METHOD FOR MANUFACTURING THE SAME}

The present invention relates to a printed circuit board and a manufacturing method thereof.

With the development of technology, electronic devices are pursuing miniaturization and light weight, and accordingly, the number of electronic components mounted on a predetermined printed circuit board area is increasing, and the width of wiring and the distance between wiring are also decreasing.

As the number of electronic components increases, heat generation problems occur, and thus, development of printed circuit boards with improved heat dissipation characteristics continues.

Republic of Korea Patent Publication No. 1999-0037873 (2013.07.03)

An object of the present invention is to provide a printed circuit board with improved heat dissipation characteristics and a manufacturing method thereof.

According to one aspect of the present invention, in a printed circuit board including a core, the core includes a first metal layer; and a heat dissipation metal formed in the first metal layer.

According to another aspect of the present invention, forming a heat dissipation metal and through-vias on a carrier; forming an insulating material between the through-via and the heat-dissipating metal; forming a first metal layer on the carrier; And there is provided a printed circuit board manufacturing method comprising the step of removing the carrier.

1 is a view showing a printed circuit board according to an embodiment of the present invention.
2 to 13 are process charts showing a method of manufacturing a printed circuit board according to an embodiment of the present invention.

Embodiments of a printed circuit board and a manufacturing method thereof according to the present invention will be described in detail with reference to the accompanying drawings, and in the description with reference to the accompanying drawings, the same or corresponding components are given the same reference numerals and Redundant descriptions will be omitted.

In addition, terms such as first and second used below are only identification symbols for distinguishing the same or corresponding components, and the same or corresponding components are not limited by terms such as first and second. no.

In addition, coupling does not mean only the case of direct physical contact between each component in the contact relationship between each component, but another configuration intervenes between each component so that the component is in the other configuration. It should be used as a concept that encompasses even the case of contact with each other.

printed circuit board

1 is a diagram showing a printed circuit board according to an embodiment of the present invention.

Referring to FIG. 1 , a printed circuit board according to an embodiment of the present invention includes a core, and the core includes a first metal layer 120 and a heat dissipation metal 110 . The heat dissipation metal 110 is formed in the first metal layer 120 . That is, the first metal layer 120 is formed to surround the heat dissipation metal 110 .

The first metal layer 120 may include copper (Cu), aluminum (Al), magnesium (Mg), titanium (Ti), hafnium (Hf), zinc (Zn), tungsten (W), molybdenum (Mo), and the like. can In addition, the metal layer 120 may be an alloy such as Invar or Kovar.

The first metal layer 120 may be formed in bar to improve the rigidity of the core.

The heat dissipation metal 110 improves heat dissipation characteristics of the core. The heat dissipation metal 110 may include copper (Cu), aluminum (Al), magnesium (Mg), titanium (Ti), hafnium (Hf), zinc (Zn), tungsten (W), molybdenum (Mo), and the like. there is.

The heat dissipation metal 110 may be formed of copper having high thermal conductivity so as to have excellent heat dissipation characteristics.

The first metal layer 120 and the heat dissipation metal 110 may be formed by electroplating on the seed layer M made of a metal material. In the final product of the printed circuit board, at least a portion of the seed layer (M) remains, and in FIG. 1, the seed layer (M) is denoted as M.

The core of the printed circuit board may further include a second metal layer 130 .

The second metal layer 130 may be stacked on the first metal layer 120 and the heat dissipation metal 110 . In addition, the second metal layer 130 may also be formed on the seed layer M. The second metal layer 130 is formed to improve adhesion between the insulating layer 150 and the first metal layer 120 to be described later.

For example, when the first metal layer 120 is made of invar, since invar has poor adhesion with the insulating layer 150, the second metal layer 130 made of copper has good adhesion with the insulating layer 150 on the invar. ) to form

The second metal layer 130 may be formed of the same metal as the heat dissipation metal 110 . As described above, the second metal layer 130 may include copper, but aluminum (Al), magnesium (Mg), titanium (Ti), hafnium (Hf), zinc (Zn), tungsten (W), molybdenum (Mo) and the like, but is not limited to these metals.

An insulating layer 150 is formed on the second metal layer 130 .

The insulating layer 150 may be a resin material. That is, the insulating layer 150 may include a thermosetting resin such as epoxy resin or a thermoplastic resin such as polyimide (PI).

In addition, the insulating layer 150 may further include a reinforcing material in the resin. The reinforcing material may be, for example, a fabric reinforcing material or an inorganic filler. The fabric reinforcing material may be glass fiber, and the glass fiber may be impregnated with a resin to form a prepreg (PPG). These reinforcing materials impart rigidity to the insulating layer 150 .

A circuit (C) is formed on the core, and the insulating layer 150 insulates the metal core from the circuit (C).

Meanwhile, the printed circuit board may further include through-vias 210 penetrating the core.

The through-via 210 may be formed of the same metal as the heat dissipation metal 110 . While the core is made of two types of metal, the first metal layer 120 and the heat dissipation via, the through via 210 is made of one type of metal. Meanwhile, the through via 210 is a via for signal transmission.

The thickness of the through-via 210 may match the thickness of the core. In particular, when the core includes the second metal layer 130, upper and lower surfaces of the through-vias 210 may coincide with upper and lower surfaces of the core, respectively.

An insulating material 140 is formed between the side surface of the through via 210 and the core. Since both the through-via 210 and the core are conductive, an insulating material 140 is required between them to prevent unnecessary shorting.

The insulating material 140 may be photosensitive. That is, the insulating material 140 may be a material called PID. Photosensitivity means the property of reacting to light. Since the photosensitive insulating material 140 is a material capable of undergoing a photolithography process, a photolithography process may be performed on the photosensitive insulating material 140 itself, and a separate photoresist R is not required. Thus, the printed circuit board manufacturing process is simplified.

The insulating material 140 may be formed between the side surface of the through-via 210 and the side surface of the heat dissipation metal 110 . That is, the through-via 210 and the heat-dissipating metal 110 may be positioned adjacent to each other so that the insulating material 140 is interposed therebetween.

As shown in FIG. 1, the thickness of the photosensitive insulating material 140 is smaller than the thickness of the core. In particular, when the core includes the second metal layer 130, the thickness of the photosensitive insulating material 140 is smaller than that of the core.

A separation space is provided between the through-via 210 and the heat dissipation metal 110, and the insulation material 140 is located in the separation space. The insulation material 140 does not fill the entire separation space, but only a part of it. .

The above-described insulating layer 150 fills the remainder of the separation space not filled with the insulating material 140 . That is, the insulating material 140 and the insulating layer 150 are in contact with each other within the separation space.

A difference between the thickness of the insulating material 140 and the thickness of the core may be the same as that of the second metal layer 130 and the seed layer M.

A connection via 220 is formed in the insulating layer 150 . The connection via 220 is connected to the through via 210 . A circuit (C) is formed on the insulating layer 150, and the circuit (C) may also be located on the connection via 220. A solder ball is formed in the circuit C formed on the connection via 220, and the printed circuit board can be connected to an external device through the solder ball.

Printed circuit board manufacturing method

2 to 13 are process charts showing a method of manufacturing a printed circuit board according to an embodiment of the present invention.

Referring to FIG. 2 , a heat dissipation metal 110 and through vias 210 are formed on a carrier.

The carrier may be composed of an insulating material (P) and two layers of metal material laminated on the insulating material (P). In FIG. 2 , only one of the two layers of metal materials is shown, and the metal material is named a seed layer (M) and denoted by M.

The insulating material P of the carrier may be a prepreg (PPG) or a build up film. The prepreg may include a reinforcing material such as glass cloth. The build-up film may be a resin material filled with a filler such as silica, and ABF (Ajinomoto Build-up Film) or the like may be used.

A total thickness of the carrier and the seed layer M may be about 0.1 mm.

Referring to FIG. 3 , a photoresist R is formed on the carrier. A thickness of the photoresist R may be about 75 um.

The photoresist R is photosensitive and is required to perform a photolithography process. After the photoresist R is deposited on the entire surface of the carrier, it is partially exposed using a mask. When the photoresist R is developed after exposure, it remains corresponding to the mask. That is, an opening region is partially formed in the photoresist R.

Meanwhile, although the process is performed on only one side of the carrier in the drawing, the process may be performed on both sides of the carrier at the same time. When the process is performed on both sides of the carrier, two printed circuit boards can be manufactured at the same time.

Referring to FIG. 4 , a plating layer is formed in the opening area. The plating layer is through via 210 and heat dissipation metal 110 . Here, a portion of the heat dissipation metal 110 surrounds the through via 210 .

The plating layer may have a thickness of about 50 um or more.

The through-via 210 and the heat dissipation metal 110 may be electroplated based on the seed layer (M). When electrolytic plating is performed, the through-via 210 and the plating layer of the heat dissipation metal 110 grow vertically from the seed layer M. The thickness of the plating layer is not limited, but may be equal to or less than the thickness of the photoresist R.

The seed layer M may be copper, and the plating layer may also be copper. In particular, the heat dissipation metal 110 may be copper having good thermal conductivity. An important feature in this step is that the through-vias 210 are formed by plating. In addition, the through-via 210 is simultaneously formed in the same process as the heat dissipation metal 110 .

Referring to FIG. 5 , the photoresist R is removed after forming the plating layer. The photoresist R may be removed by a peeling method. That is, when the printed circuit board is immersed in the stripper, the photoresist R reacting to the stripper may be removed. When the photoresist R is removed, only the plating layer, that is, the heat-dissipating metal 110 and the through-via 210 remain on the carrier.

Referring to FIG. 6 , a photosensitive insulating material 140 is formed on the carrier. A photosensitive insulating material 140 may be applied on the carrier. The applied photosensitive insulating material 140 may be cured. The photosensitive insulating material 140 covers both the heat dissipation metal 110 and the through via 210 . The photosensitive insulating material 140 may be formed to be higher than the height of the heat dissipation metal 110 and the through via 210 .

In this step, the photosensitive insulating material 140 is patterned. As described above, when the photosensitive insulating material 140 is used, a separate resist R is not required. A photolithography process may be performed directly on the photosensitive insulating material 140 . That is, when a mask is placed on the photosensitive insulating material 140 and selectively exposed and developed, the photosensitive insulating material 140 remains only for a desired portion.

In the present invention, the 'desired portion' is between the through-via 210 and the heat dissipation metal 110. The photosensitive insulating material 140 serves to insulate the through-via 210 from the core. However, since the heat dissipation metal 110 is formed before the first metal layer 120 in the printed circuit board manufacturing step, the heat dissipation metal 110 and the through vias 210 are required to insulate the core and the through vias 210. Preferably insulated.

For this reason, a part of the heat dissipation metal 110 is formed adjacent to the through via 210 .

Meanwhile, the photoresist R may be formed at the boundary between units at the strip substrate level. In addition, a photosensitive insulating material 140 may be formed on the boundary portion. In this case, in the process of cutting unit by unit, since there is almost no metal part on the boundary, there is no need to etch the metal part.

In the past, when cutting unit by unit, when etching the first metal layer 120 and the second metal layer 130, it was difficult to control because the etching rate was different from each other, but in the present invention, etching is not performed. Therefore, the above problem does not occur.

Referring to FIG. 7 , a result in which the photosensitive insulating material 140 remains only between the through via 210 and the heat dissipating metal 110 is shown. Meanwhile, the photosensitive insulating material 140 in the remaining area except for the area between the through-via 210 and the heat-dissipating metal 110 is removed, and the first metal layer 120 is formed in its place. That is, on the carrier, the through-via 210 and the heat dissipation metal 110 are formed, then the insulating material 140 is formed, and the first metal layer 120 is formed over the entire remaining area.

After the first metal layer 120 is formed, upper surfaces of the through vias 210 , the heat dissipating metal 110 , and the first metal layer 120 may be polished to make the upper surfaces flat. Also, in order to make the heights of the through-vias 210, the heat dissipation metal 110, and the first metal layer 120 desired, the upper surfaces thereof may be polished.

The first metal layer 120 is also electroplated based on the seed layer (M). The first metal layer 120 is formed by growing a plating layer from the seed layer M in the vertical direction of the printed circuit board.

Referring to Figure 8, the carrier is removed. However, the seed layer (M) remains on the printed circuit board. Specifically, as the two metal materials of the carrier are separated, one metal material is separated along with the insulating material (P), and the other metal material, that is, only the seed layer (M) remains.

Referring to FIG. 9 , a portion of the seed layer M is removed. Here, the seed layer M is removed by etching. The region from which the seed layer M was removed is indicated as E in FIG. 9 .

When the seed layer M is removed, an etching resist R is formed on the printed circuit board. That is, since protection against etching is required for an area other than the area E to be etched, the etching resist R is formed only in the corresponding area. A thickness of the etching resist R may be 25 μm or less.

The printed circuit board to which the etching resist R is attached is immersed in an etchant, and the seed layer M reacting to the etchant is removed.

Referring to FIG. 10 , when the etching of the seed layer M is completed, the etching resist R is removed. Removal of the etching resist R may be performed by a peeling method. That is, when the printed circuit board on which the etching resist R is formed is immersed in the stripping solution, the etching resist R reacting to the stripping solution is removed. When the etching resist R is removed, the photosensitive insulating material 140 is exposed.

Referring to FIG. 11 , a second metal layer 130 is formed on the first metal layer 120 . In addition, a second metal layer 130 is formed on the seed layer M. The second metal layer 130 does not cover the photosensitive insulating material 140 .

The second metal layer 130 may be copper and may have a thickness of 5 μm.

In addition, an insulating layer 150 is formed on the second metal layer 130 . The insulating layer 150 may be a prepreg or a build-up film. The thickness of the insulating layer 150 may be 20 ~ 25um.

The second metal layer 130 secures adhesion between the insulating layer 150 and the first metal layer 120 .

Referring to FIG. 12 , via holes VH are formed in the insulating layer 150 . The via hole VH may be formed with a laser drill or the like. When the via hole VH is formed with a laser drill, a tapered shape may be formed as shown in FIG. 12 . The laser drill may be a CO2 laser.

The via hole VH is formed to correspond to the through via 210 . Meanwhile, the via hole VH penetrates only the insulating layer 150 and does not penetrate the through via 210 . When the via hole VH is formed with a laser drill, since the laser can only remove the insulating layer 150, it can be controlled to penetrate only the insulating layer 150.

Referring to FIG. 13 , a conductive material is filled in the via hole VH to form a connection via 220 . The connection via 220 contacts the through via 210 and electrically connects the through via 210 and the circuit C. The connection via 220 and the through via 210 become signal transmission vias.

Filling the conductive material may be performed by a plating method. In this case, after the electroless plating layer is first formed in the via hole VH, the electroplating layer is formed on the electroless plating layer to perform peel plating on the via hole VH.

Meanwhile, when the connection via 220 is formed, the circuit C may be simultaneously formed. The circuit (C) may be formed by methods such as additive, subtractive, semi-additive, etc., but is not limited to these methods. The circuit (C) may be formed of a metal such as copper.

In the above, one embodiment of the present invention has been described, but those skilled in the art can add, change, delete, or add components within the scope not departing from the spirit of the present invention described in the claims. The present invention can be variously modified and changed by the like, and this will also be said to be included within the scope of the present invention.

110: heat dissipation metal
120: first metal layer
130: second metal layer
140: insulating material
150: insulating layer
210: through via
220: connection via

Claims (17)

It includes a core and a through-via penetrating the core,
the core
radiant metal;
a first metal layer covering at least a portion of a side surface of the heat dissipating metal; and
A second metal layer in close contact with the heat dissipation metal and the first metal layer and disposed on the heat dissipation metal and the first metal layer;
The through-via does not contact the heat dissipation metal and the first metal layer;
A photosensitive insulating material is disposed between a side surface of the through-via and a side surface of the heat-dissipating metal.
delete According to claim 1,
The second metal layer and the heat dissipation metal are formed of the same metal.
delete According to claim 1,
The through-via is formed of the same metal as the heat dissipation metal.
According to claim 5,
The photosensitive insulating material is disposed between the through-via side and the core.
According to claim 6,
The thickness of the photosensitive insulating material is smaller than the thickness of the core printed circuit board.
delete According to claim 1,
A printed circuit board further comprising an insulating layer laminated on the core.
forming a heat dissipation metal and through-vias on the carrier on which the seed layer is formed;
forming a photosensitive insulating material between the through-via and the heat-dissipating metal;
forming a first metal layer on the carrier;
removing the carrier;
removing a portion of the seed layer corresponding to the photosensitive insulating material; and
Stacking a second metal layer on the seed layer and the first metal layer; includes,
The first metal layer covers at least a portion of a side surface of the heat dissipating metal,
The second metal layer is in close contact with the heat dissipation metal and the first metal layer,
The through-via does not contact the heat dissipation metal and the first metal layer;
The photosensitive insulating material is disposed between a side surface of the through-via and a side surface of the heat-dissipating metal;
In the step of forming a photosensitive insulating material between the through via and the heat dissipation metal,
Forming the photosensitive insulating material on the carrier;
A method of manufacturing a printed circuit board comprising removing a photosensitive insulating material on a region other than between the through-via and the heat-dissipating metal.
delete According to claim 10,
In the step of forming the heat dissipation metal and through-vias,
The heat-dissipating metal and the through-via are formed by plating. According to claim 12,
The heat dissipation metal and the through-via are electrolytically plated on the seed layer.
delete delete According to claim 10,
After the step of laminating the second metal layer,
The method of manufacturing a printed circuit board further comprising forming an insulating layer on the second metal layer.
It includes a core and a through-via penetrating the core,
the core
radiant metal;
a first metal layer covering at least a portion of a side surface of the heat dissipating metal; and
A second metal layer in close contact with the heat dissipation metal and the first metal layer and disposed on the heat dissipation metal and the first metal layer;
The through-via is formed of the same metal as the heat dissipation metal,
A photosensitive insulating material is formed between a side surface of the through-via and the core;
The thickness of the photosensitive insulating material is smaller than the thickness of the core,
The through-via does not contact the heat dissipation metal and the first metal layer.

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