KR20140087541A - Solder printed circuit board and method for solder-printing circuit board - Google Patents

Abstract

The present invention relates to a solder printed circuit board and a solder printing method for a circuit board. According to one embodiment of the present invention, there is provided a semiconductor device comprising: a metal layer forming a circuit pattern; A solder resist layer formed on the metal layer and having an open region, wherein the surface roughness of the exposed open area surface and the upper surface around the open area is improved; A surface treatment (SF) layer formed on the metal layer region exposed by the open region and having improved surface roughness; And a solder formed on the SF layer and over the improved surface roughness of the solder resist layer. A solder printing method for a circuit board is also proposed.

Description

Description SOLDER PRINTED CIRCUIT BOARD AND METHOD FOR SOLDER-PRINTING CIRCUIT BOARD BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a solder printed circuit board and a solder printing method for a circuit board.

Due to the characteristics of solder printing used as a method of soldering in the PCB industry, the wettability of each layer varies depending on the surface treatment (SF) layer and the kind of the solder resist. As a result, defects such as dropout and non-filling are caused by product specifications.

Solder printing technology refers to a technique of soldering using a metal mask in which an open section is formed along with a solder resist open area (SRO) design in which solder is to be filled. When printing, push the solder paste into the squeegee to fill the solder resist open area (SRO) of the PCB through the open section of the metal mask, remove the metal mask after the squeegee passes, The solder will cool inside the SRO and print will be complete. Soldering is completed while an alloy of a surface treatment (SF) layer and a metal layer, for example, a Cu layer, is formed after the solder printing is reflowed. At this time, if the surface finishing layer formed on the metal layer through the solder resist open region and the unfilled and de-wetted solder paste are generated according to the surface condition of the solder resist, .

A conventional solder printed circuit board is shown in FIG. 3, which shows the internal state of the unfilled solder resist 20 open area (SRO). The reference symbol 'A' denotes an unfilled area. Due to the unfilled solder paste, the surface treatment (SF) layer 30 and the copper (Cu) layer 10 can not form an alloy at the time of reflow, resulting in a failure of a missing bump. This type of defects is increasing in specifications where the wettability is relatively weak as the surface finishing gradually forms the pad for the solder (50) seating.

Korean Patent Publication No. 10-2012-0012347 (published on Feb. 9, 2012)

It is an object of the present invention to provide a solder printed circuit board with improved wettability.

Another object of the present invention is to provide a solder printing method of a circuit board having improved wettability.

In order to solve the above-described problems, according to a first embodiment of the present invention, there is provided a semiconductor device comprising: a metal layer forming a circuit pattern; A solder resist layer formed on the metal layer and having an open region, wherein the surface roughness of the exposed open area surface and the upper surface around the open area is improved; A surface treatment (SF) layer formed on the metal layer region exposed by the open region and having improved surface roughness; And a solder formed on the SF layer and over the improved surface roughness of the solder resist layer.

At this time, in one example, the metal layer includes a copper (Cu) material, and the SF layer includes any one of tin, organic solderability preservative (OSP), gold (Au) can do.

Further, in one example, the surface roughness of the solder resist layer and the SF layer is formed by plasma treatment.

Next, in order to solve the above-mentioned problems, according to a second embodiment of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: forming a solder resist layer having an open region on a metal layer forming a circuit pattern; Forming a surface treatment (SF) layer on the exposed metal layer through the open region; Depositing a metal mast larger than the open area on the solder resist layer and improving the surface roughness of the exposed surface of the SF layer and the open area surface of the solder resist layer and the upper surface around the open area; And performing solder printing so that the solder is formed on the surface roughness improved SF layer and on the surface roughness improved area of the solder resist layer.

In this case, in one example, the metal layer includes a copper (Cu) material, and the SF layer is made of a material containing any one of tin, organic solderability preservative (OSP), gold (Au) As shown in FIG.

In another example, the SF layer may be formed by immersion tin plating, formation of an OSP (Organic Solderability Preservative) coating, electroless nickel plating, immersion gold plating, electrolytic gold plating, immersion silver plating As shown in FIG.

Further, in one example, in the step of improving the surface roughness, the plasma treatment may be performed to improve the surface roughness.

In another example, the step of performing solder printing may further include removing the metal mask to form a solder printed circuit board.

According to an embodiment of the present invention, a solder printed circuit board with improved wettability can be manufactured.

According to one embodiment, the surface area of the inside of the open area (SRO) of the solder resist and the surface finishing layer is increased to increase the wettability of the solder and thus the bonding force between the solder and the surface treatment Can be strengthened.

In addition, the defective ball can be reduced accordingly.

In addition, it becomes possible to remove foreign matter which may be generated when moving between the surface treatment (SF) layer forming step and the solder printing step.

It is apparent that various effects not directly referred to in accordance with various embodiments of the present invention can be derived by those of ordinary skill in the art from the various configurations according to the embodiments of the present invention.

1 is a schematic illustration of a solder printed circuit board according to one embodiment of the present invention.
FIGS. 2A through 2E are views schematically showing steps of a solder printing method of a circuit board according to another embodiment of the present invention.
3 is a schematic illustration of a conventional solder printed circuit board.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing the configuration of a first embodiment of the present invention; Fig. In the description, the same reference numerals denote the same components, and a detailed description may be omitted for the sake of understanding of the present invention to those skilled in the art.

As used herein, unless an element is referred to as being 'direct' in connection, combination, or placement with other elements, it is to be understood that not only are there forms of being 'directly connected, They may also be present in the form of being connected, bonded or disposed.

It should be noted that, even though a singular expression is described in this specification, it can be used as a concept representing the entire constitution unless it is contrary to, or obviously different from, or inconsistent with the concept of the invention. It is to be understood that the phrases "including", "having", "having", "including", and the like in the present specification are to be construed as present or absent from one or more other elements or combinations thereof.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings, in which: FIG.

Solder  Printed circuit board

First, a solder printed circuit board according to a first embodiment of the present invention will be specifically described with reference to the drawings. Here, reference numerals not shown in the drawings to be referred to may be reference numerals in other drawings showing the same configuration.

1 is a schematic illustration of a solder printed circuit board according to one embodiment of the present invention.

Referring to FIG. 1, a solder printed circuit board includes a metal layer 10, a solder resist layer 20, a surface treatment (SF) layer 30, and a solder 50.

First, the metal layer 10 forms an outer circuit pattern of the circuit board.

For example, the metal layer 10 is formed of a material containing copper (Cu). For example, the metal layer 10 may be a copper foil layer deposited on an insulating layer (not shown) or a copper (Cu) plated layer. At this time, the circuit pattern may be formed by a tenting method, a Semi Additive Process (SAP) method, an MSAP (Modified Semi Additive Process) method, or the like.

Next, referring to FIG. 1, the solder printed circuit board has a solder resist layer 20. At this time, the solder resist layer 20 is formed on the metal layer 10. In addition, the solder resist layer 20 is provided with an open area (SRO: Solder Resist Opening). The metal layer 10 is exposed through the open region of the solder resist layer 20. [ The solder resist layer 20 has improved surface roughness of the exposed open area surface and the upper surface around the open area. Thus, the wettability of the solder 50 can be improved when the solder 50 is printed in the open area. A reference character 'P' shown in FIG. 1 indicates a surface with improved surface roughness.

For example, in one example, the surface of the solder resist layer 20 that has improved surface roughness, i.e., the exposed open area surface and the exposed upper surface around the open area, has a surface roughness It is an improvement.

Next, referring to FIG. 1, the solder printed circuit board has a surface treatment (SF) layer 30. A surface finishing (SF) layer 30 is formed on the region of the metal layer 10 exposed by the open region of the solder resist layer 20. The SF layer 30 becomes a metal layer pad for attaching the solder 50. At this time, the surface treatment layer, that is, the surface of the SF layer 30, has improved surface roughness. Thus, the wettability of the solder 50 printed on the SF layer 30 can be improved.

For example, in one example, the surface roughness improvement of the SF layer 30 can be achieved by a plasma treatment.

In addition, in one example, the SF layer 30 may be formed of a material containing any one of tin, organic solderability preservative (OSP), gold (Au), and silver (Ag). At this time, in the case of tin, the SF layer 30 can be formed by electroless plating, for example, immersion plating. OSP is an organic compound in the form of Alkyl Imidazole, which forms a film of about 0.2 to 0.4 micron, which prevents oxidation of the metal layer 10. The electroless nickel plating may be performed on the metal layer 10, for example, copper (Cu), and the electroless gold plating, for example, immersion gold plating may be performed on the nickel plating layer to form the SF layer 30. Alternatively, the SF layer 30 may be formed by an electroless silver plating, such as an immersion silver plating method.

Next, referring to FIG. 1, the solder printed circuit board is provided with solder 50. At this time, the solder 50 is adhered on the SF layer 30 through the open region of the solder resist layer 20. That is, the solder 50 is adhered on the SF layer 30 with improved surface roughness and on the exposed upper surface of the solder resist layer 20 where the surface roughness is improved, that is, do. The wettability of the solder 50 can be improved by attaching the solder 50 to the region where the surface roughness is improved.

Circuit board Solder Printing  Way

Next, a solder printing method of a circuit board according to a second embodiment of the present invention will be described in detail with reference to the drawings. At this time, the solder printed circuit board according to the first embodiment described above will be referred to, and thus redundant explanations can be omitted.

FIGS. 2A through 2E are views schematically showing steps of a solder printing method of a circuit board according to another embodiment of the present invention.

2A to 2D, a solder printing method of a circuit board according to one example includes a solder resist layer forming step (see FIG. 2A), a surface treatment (SF) layer forming step (see FIG. 2A) 2b) and a solder printing step (see Figs. 2c and 2d). Further, referring further to FIG. 2E, the method may further include forming a solder printed circuit board.

We will look at it in detail. 2A, in the step of forming a solder resist layer, a solder resist layer 20 having an open region is formed on a metal layer 10 forming a circuit pattern.

At this time, the metal layer 10 forms an outer circuit pattern of the circuit board. For example, the metal layer 10 is formed of a material containing copper (Cu). For example, the metal layer 10 may be a copper foil layer deposited on an insulating layer (not shown) or a copper (Cu) plated layer. At this time, the circuit pattern may be formed by a tenting method, a Semi Additive Process (SAP) method, an MSAP (Modified Semi Additive Process) method, or the like.

At this time, the solder resist layer 20 is formed on the metal layer 10. For example, solder resist is coated on the metal layer 10, and an open area (SRO: Solder Resist Opening) is formed to expose the metal layer 10 through a process such as exposure and development.

Next, referring to FIG. 2A, a surface treatment (SF) layer is formed on the metal layer 10 exposed through the open region of the solder resist layer 20 in the step of forming the surface treatment layer of the solder printing method of the circuit board do.

For example, in one example, the SF layer 30 may be formed of a material containing any one of tin, organic solderability preservative (OSP), gold (Au), and silver (Ag).

Specifically, in the case of tin, the SF layer 30 can be formed by electroless plating, for example, immersion plating. OSP is an organic compound in the form of Alkyl Imidazole which forms a film of about 0.2 to 0.4 micron, which prevents the oxidation of the metal layer 10, for example, the copper layer. Further, in the method of forming the SF layer 30 using gold, there is a method of forming a gold-plated layer on the nickel plating layer. For example, the electroless nickel plating is performed on the metal layer 10, for example, copper, and then the electroless gold plating, such as immersion gold plating, is performed on the nickel plating layer to form the SF layer 30. In addition, the SF layer 30 may be formed by electroless silver plating, for example, immersion silver plating.

Next, referring to FIG. 2B, in the step of improving the surface roughness, a metal mast, which is opened larger than the open area SRO of the solder resist layer 20, is laminated on the solder resist layer 20. At this time, the metal mask may be a dry film mask. Since the open area of the metal mask is larger than the open area of the solder resist layer 20, the surface roughness of the upper surface around the open area of the solder resist layer 20 exposed by the open section of the metal mask when the surface roughness is improved Can be improved.

A metal mask having an open section is stacked on the solder resist layer 20 and then the surface of the SF layer 30 exposed by the metal mask and the open surface area of the solder resist layer 20 and the upper surface Thereby improving the surface roughness. At this time, the surface roughness improvement work for the exposed region by the open section of the metal mask is for improving the wettability of the solder 50 in the solder printing operation. One of the schemes for improving the wettability of the solder 50 during solder printing is a method for improving the wettability of the solder 50 in the region where the solder 50 is attached, that is, the inner surface of the open region of the SF layer 30, Thereby improving the surface roughness of the upper surface. As the surface roughness increases, the wettability of the solder 50 can be relatively increased due to the increase of the surface area. A method of improving the surface roughness is a method of raising the surface roughness through a chemical etching (etching) technique. In the case of chemical etching, there is a high probability that an additional chemical substance will attack the surface of the solder resist layer 20 and the SF layer 30, and there is a side effect on the subsequent process progress after the solder printing and on the reliability of the product ) Is relatively high. Therefore, in one embodiment of the present invention, the surface roughness can be improved by a physical method. As a surface roughness improving method by a physical method, for example, a plasma treatment can be mentioned.

For example, in one example, plasma treatment can be used to improve surface roughness. Plasma treatment is a technique of ionizing a specific gas and applying a kinetic energy of ionized cations to etch the surface by applying a high voltage or heat in a vacuum chamber. For example, the surface roughness can be improved by etching the upper surface of the substrate disposed between the upper electrode and the lower electrode due to cationized electrons ionized at the upper electrode. Referring to FIG. 2B, the surface roughness of the surface of the metal mask is improved by the plasma treatment during the plasma treatment, but since the metal mask is removed later (see FIG. 2E) The illuminance is improved.

For example, in this embodiment, a plasma operation is performed before solder printing. The plasma treatment is plasma, which forms the roughness of the wall surface of the open region of the solder resist layer 20, the exposed region around the open region, and the surface of the SF layer 30 by plasma, and improves the wettability of the solder 50 by solder printing . At this time, if the entire surface of the solder resist layer 20 is subjected to the plasma treatment, the wettability is increased over the entire surface of the solder resist layer 20, and the solder 50 is spread on the surface, The metal mask used for solder printing is laminated on the solder resist layer 20 in advance and the plasma treatment is performed so that the solder resist layer 20 excluding the section opened by the metal mask is subjected to surface treatment .

Next, referring to FIGS. 2C and 2D, solder printing is performed so that the solder 50 is formed on the SF layer 30 with improved surface roughness and on the surface roughness-improved region of the solder resist layer 20 Solder printing is performed. The wettability of the solder 50 can be improved since the solder printing is performed in the region where the surface roughness is improved. 2C and 2D, the solder paste 50 'is filled onto the SF layer 30 whose surface roughness is improved through the open section of the metal mask and onto the surface roughness-improved region of the solder resist layer 20 . The solder paste 50 'is filled in the open section of the metal mask and then the metal mask is removed and the SF layer 30 and the metal layer 10 form an alloy while reflow, 50 ') are cured to complete the soldering.

Next, referring to FIG. 2E, a solder printing method of a circuit board according to another example may further include a solder printed circuit board forming step. In the solder printed circuit board forming step, the solder printed circuit board can be formed by removing the metal mask after performing the solder printing. That is, when the solder paste is filled in the open section of the metal mask (refer to FIG. 2D), the metal mask is removed and the reflow is performed, so that the SF layer 30 and the metal layer 10 form an alloy, 50 ') are cured to complete the soldering. As a result, a solder printed circuit board is formed.

The foregoing embodiments and accompanying drawings are not intended to limit the scope of the present invention but to illustrate the present invention in order to facilitate understanding of the present invention by those skilled in the art. Embodiments in accordance with various combinations of the above-described configurations can also be implemented by those skilled in the art from the foregoing detailed description. Accordingly, various embodiments of the invention may be embodied in various forms without departing from the essential characteristics thereof, and the scope of the invention should be construed in accordance with the invention as set forth in the appended claims. Alternatives, and equivalents by those skilled in the art.

10: metal layer 20: solder resist layer
30: Surface treatment (SF) layer 40: Metal mask
50: Solder

Claims (8)

A metal layer forming a circuit pattern;
A solder resist layer formed on the metal layer and having an open area, the solder resist layer having improved surface roughness of the exposed open area surface and the upper surface around the open area;
A surface treatment (SF) layer formed on the metal layer region exposed by the open region and having improved surface roughness; And
Solder formed on the SF layer and over the area of the solder resist layer having improved surface roughness; And a solderless printed circuit board.
The method according to claim 1,
Wherein the metal layer comprises a copper (Cu) material,
Wherein the SF layer comprises any one of tin, organic solderability preservative (OSP), gold (Au), and silver (Ag).
The method according to claim 1 or 2,
Wherein the surface roughness of the solder resist layer and the SF layer is formed by a plasma treatment.
Forming a solder resist layer having an open region on a metal layer forming a circuit pattern;
Forming a surface treatment (SF) layer on the exposed metal layer through the open region;
Depositing a metal mast larger than the open area on the solder resist layer and improving the surface roughness of the exposed surface of the SF layer and the upper surface of the open area around the open area and the open area of the solder resist layer ; And
And performing solder printing so that solder is formed on the SF layer with improved surface roughness and over the surface roughness improved area of the solder resist layer.
The method of claim 4,
Wherein the metal layer comprises a copper (Cu) material,
Wherein the SF layer is formed of a material containing at least one of tin, organic solderability preservative (OSP), gold (Au), and silver (Ag).
The method of claim 5,
Wherein the SF layer is formed by one of the following methods: Immersion tin plating, Organic Solderability Preservative (OSP) film formation, Electroless nickel plating, Immersion gold plating, Electrolytic gold plating, Immersion silver plating Method of solder printing of circuit boards.
The method according to any one of claims 4 to 6,
Wherein the step of improving the surface roughness comprises performing a plasma treatment to improve the surface roughness.
The method according to any one of claims 4 to 6,
Further comprising the step of removing the metal mask to form a solder printed circuit board after performing the solder printing.

Images