KR20110123171A - Method for coating photo solder ressist using vacuum lamination and printed-circuit-board fabricated using the same - Google Patents

Abstract

PURPOSE: A method for coating photo solder resist using a vacuum lamination is provided to improve surface flatness to be over two times by planarizing the photo solder resist using vacuum lamination. CONSTITUTION: A printed circuit board(900), which includes circuit patterns(910, 915), is prepared. Photo solder resists(920, 925) for protecting a circuit pattern are formed in the printed circuit board. The printed circuit board is loaded in a vacuum chamber. A carrier film and the photo solder resist are compressed with a compression plate(940) in the vacuum chamber. The printed circuit board is thermally compressed and the photo solder resist is planarized. The carrier film is removed.

Description

TECHNICAL FOR COATING PHOTO SOLDER RESSIST USING VACUUM LAMINATION AND PRINTED-CIRCUIT-BOARD FABRICATED USING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photo solder resist coating method using a vacuum lamination method and a printed circuit board manufactured using the same, and to flattening a photo solder resist formed on the printed circuit board. The present invention relates to a technology that can reduce the thickness of and reduce the occurrence of defects by improving problems such as dimples.

In general, a photoresist, a solder resist, or the like is closely adhered or coated on a printed circuit board used in a field of a semiconductor, an LCD, and the like. At this time, the solder resist or the like is used for the purpose of coating the surface of the printed circuit board or used as an interlayer resin insulating layer.

Such solder resists should be formed to have a uniform layer thickness, and at the same time, they are often formed on both sides of a printed circuit board. For this purpose, a roller coater is mainly used.

Conventional roller coaters use a method of transferring a resist layer to a double-sided printed circuit board most often.

In particular, while coating the both sides of the substrate at the same time, while moving the double-sided substrate from the bottom up, the roller is configured to proceed vertically to transfer the coating by coating the photoresist ink on the printed circuit board.

However, when the coating proceeds vertically in such a conventional photoresist coating method, there is a problem in that thickness variation of the upper and lower ends occurs after curing.

On the other hand, to date, facilities that continuously coat and dry photosolder resist (PSR), such as reel to reel or roll to roll, actually have a problem in constructing means for drying in the manufacturing process structure. There is no way to improve the degree of flattening, because of the difficulty of contamination of the liquid ink, change of the direction of travel, and the like.

That is, the prior art has many disadvantages in productivity and process cost because it cannot proceed printing (or coating) and curing (or drying) continuously, and has a process structure that is vulnerable to contamination.

1 is a three-dimensional state diagram showing the surface flatness of a printed circuit board according to the prior art.

Referring to FIG. 1, the surface of the printed circuit board manufactured by the photosolder coating apparatus as described above is simulated, and the surface planarization degree is very low.

It is necessary to uniformly control the thickness of the photosolder coating coated on the substrate in the process of continuously coating the photosolder resist (PSR) such as reel to reel or roll to roll. There is a problem that adjustment is not easy.

As a result, the occurrence of defects in the printed circuit board may increase due to surface curvature, and may cause a problem in that the reliability of the product may be deteriorated when the chip is mounted on the printed circuit board in a subsequent process.

According to the present invention, a photosolder resist (PSR) is formed on a printed circuit board, but a carrier film is formed on the photosolder resist, and the photosolder resist is naturally flattened by a vacuum lamination method, thereby forming a printed circuit board. It is an object of the present invention to provide a photosolder resist coating method using a vacuum lamination method for improving the flatness of photosolder resist.

In addition, an object of the present invention is to provide a printed circuit board including a high flattened photosolder resist as described above.

The photosolder resist coating method using the vacuum lamination method according to the present invention comprises the steps of (a) forming a photosolder resist (PSR) on the printed circuit board, and (b) forming a carrier film on the photosolder resist. And (c) loading the printed circuit board through the step (b) into a vacuum chamber, and (d) lowering the pressure in the vacuum chamber, by pressing the carrier film and the pressure plate in the vacuum chamber. Allowing the photosolder resist to be compressed, (e) placing the printed circuit board of step (d) between the thermal compression plates, and thermally compressing the flattened photosolder resist, and (f) the carrier film. Characterized in that it comprises a step of removing.

Here, the photosolder resist of step (a) is characterized in that formed by one or more of the screen coating method, rolling coating method and curtain coating method, wherein the screen coating method is a first screen coating, first curing, first Characterized in that the process proceeds in the order of the second screen coating and the second curing, the rolling coating method is characterized in that the process proceeds in the first rolling, squeezing, the second rolling and curing order And, the curing is characterized in that using a tunnel oven or a box oven.

In addition, after the curing is characterized in that the process further proceeds in the third rolling and finishing curing order.

Next, the carrier film is positioned on the photosolder resist at the same time as the printed circuit board of step (b) is loaded into the vacuum chamber, it is bonded to the photosolder resist by the pressing plate The step (d) is characterized in that the carrier film and the PSR are compressed in the vacuum chamber by a thermal compression method.

Next, the photosolder resist coating step is further performed between the steps (d) and (e).

In addition, the printed circuit board according to the present invention is manufactured by the above-described vacuum lamination photo solder resist coating method and has a flattened photo solder resist.

According to the present invention, a photosolder resist (PSR) is formed on a printed circuit board, a carrier film is formed on the photosolder resist, and the photosolder resist is naturally flattened by a vacuum lamination method, thereby manufacturing a conventional photosolder resist. It improves the surface roughness by more than two times than the method, and provides the effect of lowering the photosolder ink ink thickness by less than half.

Accordingly, the present invention can reduce the overall thickness of the printed circuit board, and eliminates the problem of occurrence of defects such as dimples in advance, thereby providing an effect of improving the printed circuit board manufacturing yield.

1 is a three-dimensional state diagram showing the surface flatness of a printed circuit board according to the prior art.
2 is a cross-sectional view showing a method of forming a photosolder resist screen coating method according to the present invention.
Figure 3 is a schematic diagram showing a photosolder manufacturing process of the screen coating method according to the present invention.
4 is a cross-sectional view showing a method of forming a photosolder resist rolling method according to the present invention.
5 is a schematic view showing a photosolder manufacturing process of a rolling coating method according to the present invention.
6 is a cross-sectional view illustrating a method of planarizing a photosolder resist in a vacuum lamination method according to the present invention.
7 is a cross-sectional view showing an apparatus for planarizing a photosolder resist in a vacuum lamination method according to the present invention.
8 is a perspective view illustrating a process of planarizing a photosolder resist in a vacuum lamination method according to the present invention.
9 is a cross-sectional view illustrating a process of planarizing a photosolder resist in a vacuum lamination method according to the present invention.
10 is a three-dimensional state diagram showing the surface flatness of the printed circuit board according to the present invention.

Hereinafter, a photosolder resist coating method using a vacuum lamination method and a printed circuit board manufactured using the same will be described in detail based on the above object of the present invention.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments and drawings described below in detail. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, only the embodiments are to make the disclosure of the present invention complete, it is common in the art It is provided to fully inform those skilled in the art of the scope of the invention, which is to be defined only by the scope of the claims.

The present invention is to form a photo solder resist (PSR) on the printed circuit board, the carrier film is formed on the photo solder resist, and the carrier film can be naturally planarized by the vacuum lamination method.

At this time, the method of forming the photosolder resist may be one or more of the screen coating method, rolling coating method and curtain coating method.

Here, in the case of the screen coating method or curtain coating method, a separate exposure process is not required after the coating is completed, but in the case of the rolling coating method, a separate exposure and development process may be required.

However, the present invention focuses on the overall planarization rather than focusing on the form of the photosolder resist. Therefore, consideration of the subsequent exposure process and development process will be omitted.

Therefore, looking at the specific form can be described as follows.

2 is a cross-sectional view showing a method of forming a photosolder resist screen coating method according to the present invention.

Referring to FIG. 2, the printed circuit board 100 having the circuit pattern 120 formed on one surface thereof is loaded on the support plate 110.

Next, the screen frame 130 with the coating area printed on the printed circuit board 100 is placed, and the photo solder resist is pushed through the screen frame 130 while pushing the photo solder resist 140 into the squeeze 150. Form.

Such a screen coating method of forming a photosolder resist is suitable for a single-sided printed circuit board, the print screen printing process may be performed twice or more continuously as shown in FIG.

Figure 3 is a schematic diagram showing a photosolder manufacturing process of the screen coating method according to the present invention.

Referring to FIG. 3, the screen coating process is performed in the order of the first screen coating 200, the first curing 210, the second screen coating 220, and the second curing 230. It can be seen that.

At this time, the first cure ring 210 and the second cure ring 230 is not particularly limited as a drying process, but is preferably performed using a tunnel oven or a box oven.

As described above, the screen coating is continuously performed because a single screen coating process does not form a uniform thickness of the photosolder resist over the entire area of the printed circuit board.

Therefore, conventionally, since the thickness of the photosolder resist should be uniform in the last screen coating process, there is a difficulty in controlling the process strictly.

However, in the present invention, since the flattening is possible through a subsequent vacuum lamination process, the burden of performing the screen coating process may be reduced.

Therefore, the photosolder forming method according to the present invention can improve the manufacturing yield, there is an advantage that can reduce the risk of defects.

In addition, the advantages in the photosolder forming process as described above can be applied to the rolling coating method and the curtain coating method in the same, and look at the application example for the rolling coating among them as follows.

4 is a cross-sectional view showing a method of forming a photosolder resist rolling method according to the present invention.

Referring to FIG. 4, the surface of the photosolder resist 320 using a first rolling process and a squeeze 430 to form the photosolder resist 320 on the printed circuit board 300 by the first roller 330. It can be seen a rolling coating method including a squeezing process to clean up and a second rolling process to make the thickness of the photosolder resist 320 uniform by the second roller 350.

Here, the first roller 330 and the second roller 350 is dug a groove at a uniform interval in the cylindrical roller made of silicon, urethane, or SUS, so that the photoresist ink is better transferred to the printed circuit board 300 It is desirable to be able to.

Next, when the rolling process is completed, the curing process is performed. Here, the curing is preferably performed using a tunnel oven or a box oven, and more specific examples of the rolling coating method are as follows.

5 is a schematic view showing a photosolder manufacturing process of a rolling coating method according to the present invention.

Referring to FIG. 5, as described in FIG. 4, the first rolling 400, the squeezing 410, and the second rolling 420 are sequentially processed, and a curing 430 using a tunnel oven or a box oven is performed. Perform the process.

At this time, in the present invention, the third rolling 440 process and the finishing cure 450 process may be further performed to more smoothly and uniformly supplement the surface state of the photosolder resist.

Next, the present invention uses a vacuum lamination method as a method for planarizing the surface of the photosolder resist formed on the printed circuit board through the process of FIGS. 2 to 5. same.

6 is a cross-sectional view illustrating a method of planarizing a photosolder resist in a vacuum lamination method according to the present invention.

Referring to FIG. 6, it can be seen that the printed circuit board 500 having the first photosolder resist 510 and the second photosolder resist 515 are loaded in the vacuum chamber 550 and the planarization process is performed. .

At this time, the photosolder resist is planarized by the first vacuum pressing plate 540 and the second vacuum pressing plate 545 made of a rubber material pressed by vacuum, and each photosolder resist ( The first carrier film 520 and the second carrier film 525 are preferably formed on the surfaces of the 510 and 515, respectively.

Here, the first carrier film 520 and the second carrier film 525 load the printed circuit board 500 into the vacuum chamber by the first carrier film roll 530 and the second carrier film roll 535, respectively. You can see that it is being inserted at the same time.

However, the method of attaching the carrier film to the printed circuit board 500 is not limited to the above description.

For example, before the printed circuit board 500 is loaded into the vacuum chamber 550, a carrier film may be formed in advance, and then removed after the planarization process is completed. It may also proceed without being completely bonded to the printed circuit board.

7 is a cross-sectional view showing an apparatus for planarizing a photosolder resist in a vacuum lamination method according to the present invention.

FIG. 7 illustrates a case in which the carrier film is not bonded to the printed circuit board in the description of FIG. 6, wherein the first carrier film 620 and the second carrier film 625 are applied to each roll from the vacuum laminating step to the drying step. It can be seen that the planarization process proceeds in a state where the tension is maintained in parallel.

Here, the planarization process of the photosolder resist is performed while the printed circuit board 600 having the photosolder resist is passed through the vacuum chamber 640, the thermocompressor 650, and the dryer 660.

As such, the printed circuit board 600 sequentially passes through the photosolder resist forming apparatus 700, the vacuum laminating apparatus 710, the thermocompression bonding apparatus 720, and the drying apparatus 730, and has a photosolder resist coating layer formed on the surface thereof. Should be flattened.

At this time, the carrier film is used as an auxiliary to prevent the loss of the photosolder resist, may be used in the form bonded to the photosolder resist, it may be used as a protective film only at the time of pressing.

However, in the vacuum laminating process, the photosolder resist is first compressed by the carrier film so that the overall thickness can be made uniform, and the second flattening can be completed by thermocompression bonding by a vacuum press plate made of rubber. It is desirable to.

Next, in the thermocompression process, the planarized photosolder resist is stabilized and a drying process is performed. At this time, before performing the thermocompression process, the photosolder resist coating step using the rolling coating method may be further performed to further supplement the surface state of the planarized photosolder resist.

Through the above process, the photosolder resist according to the present invention may have an excellent planarization degree of 2 times or more. In addition, the planarization process will be described briefly as follows.

8 is a perspective view illustrating a process of planarizing a photosolder resist in a vacuum lamination method according to the present invention.

Referring to FIG. 8, a printed circuit board 800 having photosolder resists formed on both surfaces thereof is loaded between a first vacuum compression plate 820 and a second vacuum compression plate 825 in a vacuum chamber, and between the compression plates. The vacuum 830 is formed to be flattened by the pressing plate.

In this case, since the carrier film is omitted in order to first look at the process of the pressing plate, the flattening process by the primary carrier film and the flattening process by the secondary pressing plate described in FIG. 7 should be maintained as it is.

Next, the printed circuit board 800 including the planarization photosolder resist is loaded between the first thermocompression plate 840 and the second thermocompression plate 845 inside the thermocompressor. Pressure is applied to allow the planarization to be completed.

This process is described below with reference to a printed circuit board.

9 is a cross-sectional view illustrating a process of planarizing a photosolder resist in a vacuum lamination method according to the present invention.

Referring to FIG. 9, photosolder resists 920 and 925 for protecting the circuit patterns 910 and 915 are respectively formed on the printed circuit board 900 including the circuit patterns 910 and 915 on both surfaces thereof.

Next, each photosolder resist is formed by a first carrier film 930, a first vacuum compression plate 940 / a second carrier film 935, and a second vacuum compression plate 945 in a vacuum chamber (not shown). Allow 920 and 925 to be flattened.

At this time, when the carrier film is supplied in parallel, the first planarization by the carrier film and the second planarization by the crimping plate may be performed. In the case where the carrier film is already formed in the photosolder resist, the first and second carriers may be used. The planarization may be performed at the same time.

In addition, the vacuum lamination photosolder planarization process according to the present invention may be performed in various ways in addition to the above two forms. For example, an order in which the process of planarizing the first photosolder resist 920 first and the process of planarizing the second photosolder resist 925 may also be included.

Next, the photosolder is formed by the first thermocompression plate 950 and the second thermocompression plate 955 to which pressure is applied at the upper and lower portions of the first carrier film 930 and the second carrier film 935, respectively. Allows the planarization of the resist to be completed.

Next, a printed circuit board 900 including the first photosolder resist 920P and the second photosolder resist 925P having excellent planarization degree is completed by a drying and carrier film removing process.

Next, the specific shape and the numerical relationship with respect to the flattening degree were directly proved by experiment, and the results are as follows.

10 is a three-dimensional state diagram showing the surface flatness of the printed circuit board according to the present invention.

FIG. 10 illustrates a photosolder resist having a thickness of 10 μm formed on both sides of a 40 mm × 40 mm sized printed circuit board according to the first embodiment of the present invention. It is also a stereoscopic state.

It can be seen that the three-dimensional shape shown in FIG. 10 has a very good flattening degree as compared with the three-dimensional shape shown in FIG. 1.

Therefore, as Comparative Example 1, the same process as in Example 1 was performed, but only a compression circuit using a vacuum lamination method was manufactured, and the characteristics thereof are shown in Table 1 below.

Surface Roughness (R) Average maximum lowest Example 1 0.38 3.37 2.46 Comparative Example 1 1.05 6.77 2.57

As shown in Table 1, it can be seen that the surface roughness value is significantly reduced when the planarization process using the vacuum lamination method according to the present invention is performed.

As described above, according to the present invention, the photosolder resist is naturally flattened by the vacuum lamination method, thereby improving surface roughness by more than two times than the conventional photosolder manufacturing method. Therefore, it is possible to reduce the photosolder ink thickness by an improved value, thereby saving raw materials and improving the yield of the manufacturing process.

In addition, the overall thickness of the printed circuit board can be reduced, and defects such as dimples can be eliminated in advance, thereby improving quality of the printed circuit board and improving production yield.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above embodiments and can be modified in various forms, and having ordinary skill in the art to which the present invention pertains. It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without changing the technical spirit or essential features of the present invention.

In particular, the description of the present invention described above focuses on the photosolder resist, which is equally applicable to photoresists used in general exposure and development processes, and thus, the embodiments described above are exemplary in all respects. It should be understood that it is not limitative.

100, 300, 500, 600, 800, 900: printed circuit board
110: support plate
120, 910, 915: circuit pattern 130: screen frame
140, 320: photosolder resist 150, 340: squeeze
200: first screen coating 210, 430: first curing
220: second screen coating 230, 450: second curing
330: first roller 350: second roller
400: first rolling 410: squeegee
420: second rolling 440: third rolling
510 and 920: first photosolder resist
515, 925: second photosolder resist
520, 620, 930: first carrier film 525, 625, 935: second carrier film
530, 610: first carrier film roll 535, 615: second carrier film roll
540, 630, 820, 940: first vacuum pressing plate
545, 635, 825, 945: second vacuum pressing plate
550, 640: vacuum chamber 650: thermocompressor
660: Dryer 700: Photo Solder Resist Forming Equipment
710: vacuum laminating equipment 720: thermocompression bonding equipment
730: drying equipment 830: vacuum
840, 950: first row pressing plate 845, 955: second row pressing plate
920P: planarized first photosolder resist
925P: planarized second photosolder resist

Claims (10)

(a) forming a photo solder resist (PSR) on the printed circuit board;
(b) forming a carrier film on the photosolder resist;
(c) loading the printed circuit board passed through step (b) into a vacuum chamber;
(d) compressing the carrier film and the photosolder resist by a pressing plate in the vacuum chamber while lowering the pressure in the vacuum chamber;
(e) placing the printed circuit board of step (d) between the thermal compression plates and thermally compressing the planarized photosolder resist; And
(f) removing the carrier film; the photosolder resist coating method using a vacuum lamination method comprising a.
The method of claim 1,
The photosolder resist of step (a) is a photosolder resist coating method using a vacuum lamination method, characterized in that formed in at least one of screen coating method, rolling coating method and curtain coating method.
The method of claim 2,
The screen coating method is a photo-solder resist coating method using a vacuum lamination method, characterized in that the process proceeds in the first screen coating, the first curing, the second screen coating and the second curing order.
The method of claim 2,
The rolling coating method is a photo-solder resist coating method using a vacuum lamination method, characterized in that the first rolling, squeezing, the second rolling and the process in the order of curing.
The method according to claim 3 or 4,
The curing is a photosolder resist coating method using a vacuum lamination method, characterized in that using a tunnel oven or a box oven.
The method of claim 4, wherein
The photosolder resist coating method using a vacuum lamination method, characterized in that further proceeding the process in the order of the third rolling and finishing curing after the curing.
The method of claim 1,
The carrier film is located on top of the photosolder resist at the same time as the printed circuit board of step (b) is loaded into the vacuum chamber, the vacuum is characterized in that bonded to the photosolder resist by the pressing plate Photo solder resist coating method using lamination method.
The method of claim 1,
The step (d) is a photosolder resist coating method using a vacuum lamination method, characterized in that the carrier film and the PSR is pressed in a vacuum chamber by a thermal compression method.
The method of claim 1,
The photosolder resist coating method using the vacuum lamination method, characterized in that for further performing a photosolder coating step between the step (d) and (e).
A printed circuit board manufactured by the vacuum lamination photo solder resist coating method of any one of claims 1 to 9 and having a flattened photo solder resist.

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