KR101882576B1 - Light sintering device having protecting damage to substrate - Google Patents

Abstract

A light sintering apparatus having a substrate damage preventing device is provided. The photo-sintering apparatus of the present invention is a vacuum-heating plate including a vacuum hole for applying a vacuum to fix a printed circuit board and a heat plate for heating or cooling the printed circuit board, a vacuum- A light output section for photo-sintering the printed circuit board, and a substrate transfer section positioned on one side of the vacuum-heating plate and for transferring the printed circuit board in one direction. The light sintering apparatus according to the present invention can reduce the wastage of the substrate caused by continuous light sintering on the printed circuit board and thus the non-uniformity of sintering. Accordingly, a single-layer or multi-layer printed circuit board having high electrical conductivity and free from warping of the substrate can be manufactured.

Description

[0001] The present invention relates to a light sintering device having a substrate damage prevention device,

The present invention relates to a light sintering apparatus, and more particularly, to a white light sintering apparatus.

BACKGROUND ART [0002] In recent years, print-based printing electronic technology has attracted attention in the manufacture of electronic devices or devices. Printed electronic technology has advantages such as low facility investment cost, eco-friendliness and large-scale mass production because it can form electrodes by simple processes such as printing, sintering and inspection. These advantages can be applied to various fields such as flexible display, solar cell, RFID (Radio Frequency Identification Device), wearable electronics (OLED), organic light emitting device And is expected to be widely used.

Among the elements of printed electronic technology, sintering technology is an important part because it directly determines the quality of electrodes. Thermal sintering method, laser sintering method, plasma sintering method, microwave sintering method and the like have been developed as conventional sintering methods, but they are difficult to commercialize due to limitations of each method. Accordingly, a white light extreme ultraviolet light sintering method has been developed by the inventor to overcome the above problems.

In order to improve the quality of the sintered electrode using the above-described sintering method, many developments are currently being made in view of the conductive ink or paste. However, when the continuous light sintering process using the conventional light irradiation equipment and the conveyor belt is performed, wrinkles of the substrate and wobbling of the substrate may lead to irregularity of light, resulting in non-uniformity of sintering. However, for practical application in the industrial field, it is necessary to have high electrical conductivity after sintering, uniformity of sintering, and no damage to the substrate. Therefore, in order to solve the above problems, a solution from the standpoint of equipment is needed.

Korean Patent Publication No. 10-2009-0023130

SUMMARY OF THE INVENTION It is an object of the present invention to provide a photo-sintering apparatus capable of reducing wrinkling of a substrate caused by continuous photo-sintering on a printed circuit board, and thus non-uniformity of sintering.

According to an aspect of the present invention, there is provided a light sintering apparatus. The light sintering apparatus includes: a vacuum hole for applying a vacuum to fix the printed circuit board; A vacuum-heating plate including a heating plate for heating or cooling the printed circuit board; a light output unit positioned above the vacuum-heating plate and optically sintering the printed circuit board by irradiating light; And a substrate transferring unit which is disposed on one side of the substrate transferring unit and transfers the printed circuit board in one direction.

The optical output unit may be connected to a vertical moving unit that can move up and down on the printed circuit board, and the optical output unit may be moved downward toward the printed circuit board when photo-sintering.

Wherein the light output portion includes upper guide rails disposed on opposite sides of the light output portion, wherein the vacuum-heating plate includes a lower guide rail disposed on a side opposite to the light output portion, And may be arranged to face each other with the substrate interposed therebetween.

Wherein the light output portion includes upper guide rails provided on two pairs of side faces facing each other, wherein the vacuum-heating plate includes lower guide rails provided on two pairs of side faces facing each other, And may be arranged to face each other with the printed circuit board interposed therebetween when moving downward.

The guide rails are rotatable, and when the light output portion moves downward, the upper guide rail and the lower guide rail turn outward from the central portion of the vacuum-heating plate, respectively, so that the printed circuit board can be unfolded .

The optical output unit may include an extreme ultraviolet-white light output unit and a far ultraviolet ray output unit located at one side of the extreme ultraviolet-white light output unit. The extreme ultraviolet-white light and the far ultraviolet light may be simultaneously or sequentially irradiated.

The extreme ultraviolet light output unit includes at least one extreme ultraviolet white light lamp, a reflector disposed above the lamp and reflecting the light, a beam guide disposed under the lamp to adjust the light path, , And an optical wavelength filter for adjusting the wavelength band of light.

The optical wavelength filter may adjust the wavelength of the light to 300 to 700 nm, and perform the light sintering by simultaneously applying the optical wavelength filter and the far ultraviolet ray output unit.

Wherein the extreme ultraviolet-white light lamp comprises a main illumination lamp and a preliminary light illumination lamp,

The preliminary light irradiation lamp may be one that irradiates light earlier than the main illumination lamp and emits light of lower intensity than that of the main illumination lamp.

The plurality of vacuum holes are spaced apart from each other in the vacuum-heating plate and a vacuum is applied to a lower portion of the printed circuit board. The holes may have a diameter of 100 μm to 1 mm and an interval of 1 cm to 5 cm.

The intensity of the vacuum may be 0.1 MPa to 0.6 MPa.

The temperature of the printed circuit board may be controlled by the vacuum-heating plate to a range of -50 ° C to 300 ° C.

The temperature of the substrate may be adjusted to 100 ° C to 300 ° C by the heating plate of the vacuum-heating plate.

The substrate transfer part may be in the form of a roll located on both sides of the vacuum-heating plate to move the printed circuit board in one direction or may be in the form of a conveyor belt that is positioned at the lower part of the printed circuit board and rotates itself.

The printed circuit board may comprise a conductive metal ink or a conductive metal paste pattern.

The printed circuit board may include a multilayer circuit pattern and a via-hole.

The method may further include a masking device for passing light through the via hole before the circuit pattern in performing the photo-sintering of the printed circuit board including the multilayer circuit pattern and the via-hole.

The light sintering apparatus according to the present invention can reduce the wastage of the substrate caused by continuous light sintering on the printed circuit board and thus the non-uniformity of sintering. As a result, a single-layer or multi-layer printed circuit board having high electrical conductivity and no damage to the substrate can be manufactured.

The technical effects of the present invention are not limited to those mentioned above, and other technical effects not mentioned can be clearly understood by those skilled in the art from the following description.

FIGS. 1A and 1B are exploded perspective views showing the structure of the light sintering apparatus according to the first embodiment and the second embodiment of the present invention, respectively.
FIGS. 2A to 2D are schematic views illustrating a process sequence of a light sintering apparatus according to an embodiment of the present invention.
3 is an image of a scanning electron microscope observing the surface of a photo-sintered printed circuit board according to an embodiment of the present invention.
4 is a graph showing the result of sintering according to Experimental Example 1 of the present invention.
FIG. 5 is a graph comparing the degree of warping of the substrate according to Experimental Example 2 of the present invention.
FIG. 6 is an image comparing the degree of bending of the substrate according to Experimental Example 3 of the present invention.
7A and 7B are photographs showing patterns of the printed circuit board according to Comparative Example 1 and Example 1, respectively.

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

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. Rather, the intention is not to limit the invention to the particular forms disclosed, but rather, the invention includes all modifications, equivalents and substitutions that are consistent with the spirit of the invention as defined by the claims.

It will be appreciated that when an element such as a layer, region or substrate is referred to as being present on another element "on," it may be directly on the other element or there may be an intermediate element in between .

FIGS. 1A and 1B are exploded perspective views showing the structure of the light sintering apparatus according to the first embodiment and the second embodiment of the present invention, respectively.

1A, a light sintering apparatus according to a first embodiment of the present invention includes a vacuum-heating plate 200 for supporting a printed circuit board 100, a light output unit 300, and a printed circuit board 100 (Not shown).

The printed circuit board 100 may be a single layer or a multilayer board, and one or both sides of each layer may be printed. For example, the single-layer printed circuit board 100 may have a circuit pattern 101 formed of a conductive metal ink or a conductive metal paste or the like. The printed circuit board 100 may include a multilayer circuit pattern 101 and a via-hole structure formed therebetween.

The substrate may be a flexible material such as a polymer or paper, or a hard material such as glass or ceramics. For example, the flexible substrate may be made of a material selected from the group consisting of photo paper, polyethylene terephthalate (PET), paper, polystyrene terephthalate, polyether, polyethylene naphthalate (PEN), vinyl acetate resin (EVA) Resin, polyimide, silicone or FR-4.

For example, the rigid substrate may include glass, polyethylene terephthalate, polysulfone, polyetherimide, acrylic resin, heat resistant epoxy, BT epoxy / glass fiber, polyarylate, ferrite or ceramic have.

The conductive metal ink or paste may comprise metal nanoparticles. The metal nanoparticles may be copper, silver, gold, platinum, iron, molybdenum, nickel, aluminum, or a combination thereof. Specifically, the metal nanoparticles may include copper or a mixture thereof. The conductive metal ink may be prepared by dispersing the metal nanoparticles, the binder and the like in a solvent.

The conductive metal ink or paste may be patterned on the substrate. Examples of the patterning method include screen printing, inkjet printing, micro-contact printing, imprinting, gravure printing, gravure-offset printing, offset printing, and flexography printing.

The light output unit 300 may be disposed on the printed circuit board 100. The light output unit 300 may be connected to a vertical movement unit (not shown) and a support (not shown) to move up and down on the printed circuit board. The light output unit 300 may be moved downward in the direction of the printed circuit board 100 during photo-sintering.

The light output unit 300 may include an upper guide rail 221 installed on one side surface. Specifically, the upper guide rail 221 may be installed at a lower end of a side surface of the light output unit 300, that is, at a position where the upper guide rail 221 can contact the printed circuit board 100.

The vacuum-heating plate 200 may be disposed under the printed circuit board 100. The vacuum-heating plate 200 may include a vacuum hole (not shown) and a thermal plate (not shown).

More specifically, the vacuum holes (not shown) are installed inside the vacuum-heating plate 200, and a plurality of vacuum holes (not shown) A vacuum may be applied to fix the printed circuit board 100 when light sintering is performed.

At this time, the intensity of the vacuum may have a range of vacuum pressure to secure the substrate 100 properly and to prevent the substrate itself from being damaged by the vacuum. Specifically, the intensity of the vacuum may be 0.1 MPa to 0.6 MPa. For example, the intensity of the vacuum may be 0.5 MPa.

Also, the proper diameter of the vacuum hole and the spacing of the holes may affect the vacuum pressure. For example, the diameter of the vacuum hole may be 100 [mu] m to 1 mm. The interval of the holes may be 1 cm to 5 cm.

The heat plate (not shown) is installed inside the vacuum-heating plate 200, and may include a heating plate and a cooling plate. For example, by heating the heating plate of the heat plate during photo- The temperature of the substrate 100, specifically, the temperature of the lower portion of the substrate 100 can be changed or maintained.

That is, in the case of the conventional light sintering apparatus, the upper (surface) portion of the printed circuit board during sintering of the conductive metal ink has relatively high sintering efficiency due to light, whereas the heat due to light is not sufficiently transmitted to the lower portion of the substrate, There is a problem that can not occur. Accordingly, the entire sintering effect of the printed circuit board can be obtained by heating the thermal plate of the vacuum-heating plate 200.

For example, the temperature of the substrate 100 may be adjusted from -50 ° C to 300 ° C. Specifically, the heating temperature of the substrate 100 controlled by the heating plate may be 100 ° C to 300 ° C. More specifically, the heating temperature of the substrate 100 may be 200 ° C.

The vacuum-heating plate 200 may further include a lower guide rail 220 installed on one side surface thereof. Specifically, it may be provided on a side surface of the vacuum-heating plate 200, and may correspond to the upper guide rails 221 of the light output unit 300 described above. The guide rails 220 and 221 may be arranged to face each other with the printed circuit board 100 interposed therebetween when the optical output unit 300 moves downward when optical sintering is performed.

The guide rails 220 and 221 are rotatable and the guide rails 220 and 221 may be rotated outward from the center of the vacuum-heating plate 200. In other words, when the light output unit 300 moves downward, the guide rails 220 and 221 correspond to each other with the printed circuit board 100 interposed therebetween, and the vacuum-heating plate 200 , So that it can be unfolded by applying a force from the center of the printed circuit board 100 to the outward direction. Thus, it is possible to prevent wasted of the substrate 100, which may be caused by light sintering.

The effect of preventing the substrate from being wrinkled by the guide rails 220 and 221 will be described in more detail with reference to FIGS. 2A to 2D to be described later according to the light sintering process.

The optical output unit 300 may include an extreme ultraviolet ray output unit 310 and a far ultraviolet ray output unit 320 disposed on one side of the extreme ultraviolet ray output unit 310. Accordingly, the optical output unit 300 can simultaneously or extensively irradiate the extreme ultraviolet light and the far ultraviolet light.

The extreme ultraviolet wave output unit 310 may include at least one lamp 312 or 313 for emitting pulse ultrafine wave light. The lamps 312 and 313 receive voltage and current from a power source unit (not shown), and receive charge accumulated from a power storage unit (not shown) to generate arc plasma to irradiate extreme ultraviolet white light.

For example, the extreme ultraviolet light output unit 310 may include a main illumination lamp 312 and a preliminary light illumination lamp 313, and the light irradiation may be sequentially performed. For example, the preliminary light irradiation lamp 313 may be irradiated with light first than the main illumination lamp 312 to increase the temperature of the printed circuit board 100. At this time, the intensity of the light emitted from the preliminary light irradiation lamp 313 may be lower than the intensity of the light emitted from the main illumination lamp 312.

That is, the preliminary light irradiation lamp 313 may be mounted on the printed circuit board 100, such as the thermal plate of the above-described vacuum-heating plate, before or during the light sintering by the main illumination lamp 312, So that a higher sintering efficiency can be provided.

For example, the lamps 312 and 313 may include gas composed of xenon, krypton, or a mixture thereof. Specifically, the lamps 312 and 313 may be xenon flash lamps. The xenon flash lamp includes xenon gas injected into a cylinder-shaped sealed quartz tube, and the xenon gas outputs light energy, specifically extreme ultraviolet light, from the input electrical energy.

The extreme ultraviolet light is a flash light that emits strong light energy at a large area at a time over a short period of time, and can have an optical spectrum in a wide wavelength band from ultraviolet to infrared rays in a wavelength range of 160 nm to 2.5 mm.

The energy of such extreme-wave white light may be about 0.1 J / cm 2 to 100 J / cm 2. Specifically, the energy of the extreme-wave white light may be 1 J / cm 2 to 70 J / cm 2. In addition, the light irradiation time can be adjusted from 0.1 ms to 100 ms, which can be implemented through a control unit (not shown) connected to the lamp. Specifically, the light irradiation time may be 0.01 ms to 30 ms. In addition, the pulse gap of the extreme-wave white light may be 0.01 ms to 30 ms, and the pulse number may be 1 to 50 times.

However, the irradiation conditions of the extreme ultraviolet ray may be adjusted depending on the type of the conductive metal ink or the type of the substrate.

The extreme ultraviolet light output unit 310 may further include a reflector 410 for reflecting the light, a beam guide 311 for adjusting the path of the light, and an optical wavelength filter 400 for adjusting the wavelength band of the light.

For example, the reflector 410 may be disposed on the upper side of the lamps 312 and 313. For example, the reflector 410 may have a semi-cylindrical shape. The reflector 410 reflects the light emitted from the lamps 312 and 313 in the direction opposite to the direction of the printed circuit board 100 to change the light path in the direction of the printed circuit board 100 . Accordingly, the amount of extreme ultraviolet light generated from the lamps 312 and 313 is transferred to the printed circuit board 100, thereby increasing energy conversion efficiency into the light energy.

The coating material inside the reflector 410 may be ceramic, gold or aluminum.

The beam guide 311 may be disposed under the lamps 312 and 313 and the optical wavelength filter 400 may be disposed within the beam guide 311. For example, The beam guide 311 may be disposed in parallel with the beam guide 311 so that light passing through the beam guide 311 may pass. Thus, the light having passed through the beam guide 311 can be filtered in a predetermined wavelength band. For example, the optical wavelength filter 400 may adjust the wavelength of light to 300 to 700 nm.

For example, the optical wavelength filter 400 may adjust the wavelength of the light to 500 to 700 nm when the conductive metal ink is a copper ink. When the conductive metal ink is a silver ink, the wavelength of the light can be adjusted to 300 nm to 500 nm. When the conductive metal ink is a mixture of copper and silver, the wavelength of the light can be adjusted to 300 nm to 700 nm.

The far ultraviolet ray output unit 320 may emit light of a short wavelength region (100 nm to 200 nm) among the far ultraviolet ray, that is, the ultraviolet ray region (wavelength region of 400 nm or less). The far ultraviolet ray can be irradiated by a continuous irradiation method instead of a pulse type. The far ultraviolet light can reduce the binder component in the conductive metal ink during the photo-sintering and can further increase the efficiency of the photo-sintering.

The energy of the far ultraviolet ray irradiated from the far ultraviolet ray output unit 320 can be irradiated to a range that does not damage the substrate itself while enhancing the light sintering efficiency. For example, based on the energy to be directly irradiated to the substrate 100 may be a 10μW / cm ² to about 100μW / cm ^2.

The far ultraviolet ray output unit 320 may perform light sintering by applying the optical wavelength filter 400 described above together. When the far ultraviolet light and the extreme ultraviolet light filtered by the optical wavelength filter 400 are simultaneously applied, the electrical resistivity of the circuit pattern 101 can be lowered to improve the electrical conductivity.

The printed circuit board 100 may be transported in one direction by the substrate transferring units 210 and 211 located on one side of the printed circuit board 100 in the optical sintering apparatus. Thus, the light sintering of the printed circuit board 100 can be performed continuously.

For example, the substrate transferring parts 210 and 211 are located on both sides of the printed circuit board 100, and the PCB transferring parts 210 and 211 are formed on the printed circuit board 100, Or may be in the form of a roll for moving the conveyor belt 100 in one direction or in the form of a self-rotating conveyor belt located below the printed circuit board 100.

1B is an exploded perspective view showing a structure of a light sintering apparatus according to a second embodiment of the present invention.

Referring to FIG. 1B, except for the following, the same contents as those described in FIG. 1A are used.

The printed circuit board 100 may include a via-hole structure 102. Hole structure 102 includes a base layer 102a, a first circuit pattern 102b, an insulating layer 102c, a via-hole 102d formed in the insulating layer 102c, and a via- Hole 102d, and a conductive metal ink may be filled in the via-hole 102d.

Holes 102d may be formed on the upper surface of the substrate 100 during the photo-sintering of the printed circuit board 100 including the via-hole structure 102, 103) can be used. Thereby, sintering of only the via-hole 102d can be individually performed without damaging the ink or the substrate.

In other words, in the printed circuit board 100 including the via-hole structure 102, since the thickness of the ink in the via-hole 102d is thicker than that of the circuit pattern 102e, Is required. Accordingly, if the via-hole 102d and the circuit pattern 102e are simultaneously photo-sintered with the same energy, ink in the via-hole 102d can not be sintered, or the printed circuit pattern 102e and the circuit pattern 102e Burn-out may occur in the printed circuit board 100 and the substrate may be damaged.

Therefore, the via-hole 102d is sintered before the circuit pattern 102e, and the via-hole 102d is formed with a higher energy than in the sintering of the circuit pattern 102e using the masking apparatus 103 The sintering of the circuit board 100 can be further improved by sintering the circuit pattern 102e with an energy lower than the energy.

FIGS. 2A to 2D are schematic views sequentially illustrating a light sintering process according to an embodiment of the present invention. FIG.

Referring to FIG. 2A, the printed circuit board 100 may be moved in one direction by the substrate transferring units 210 and 211. For example, the lower roll 210 and the upper roll 211 of the substrate transferring units 210 and 211 rotate in different directions with the printed circuit board 100 interposed therebetween, Can be moved in one direction.

For example, the lower rolls 210 rotate in a clockwise direction, and the upper rolls 211 rotate in a counterclockwise direction so that the printed circuit board 100 can be moved in the A direction. So that the circuit pattern 101 of the substrate 100 can be positioned between the light output unit 300 and the vacuum-heating plate 200.

Referring to FIG. 2B, when the printed circuit pattern 101 is located at the center between the light output unit 300 and the vacuum-heating plate 200, light emitted from the light output unit 300 Sintering can be performed. At this time, the substrate transferring parts 210 and 211 stop transferring the substrate, and a vacuum hole (not shown) of the vacuum-heating plate 200 fixes the printed circuit board 100. At this time, the printed circuit board 100 is momentarily bent (100 ') due to the substrate transfer stopping of the substrate transferring parts 210 and 211. Also, as the light sintering is performed, the warpage 100 'of the substrate due to contraction between the metal particles in the conductive metal ink forming the circuit pattern 101 is generated once again.

2C, the optical output unit 300 moves downward in the direction of the printed circuit board 100 by a vertically moving unit (not shown) during the optical sintering process, The circuit pattern 101 of FIG.

In this case, the guide rails 220 and 221 may be arranged to face each other with the printed circuit board 100 therebetween when the light output unit 300 moves downward as described above with reference to FIG. At this time, the guide rails 220 and 221 may simultaneously rotate in the outer direction from the center of the vacuum-heating plate 200 to unfold the printed circuit board 100. Accordingly, it is possible to prevent the substrate from being damaged by wrinkling of the substrate, which may be caused by the light sintering, and to improve the sintering uniformity of the electrode.

In addition, it is possible to prevent the substrate from being worn out by fixing the printed circuit board 100 by maintaining a constant vacuum pressure in the vacuum hole of the vacuum-heating plate 200 disposed at the lower part of the printed circuit board 100 .

In this case, for example, the intensity of the vacuum may have a range of vacuum pressure to secure the substrate 100 properly and prevent the substrate itself from being damaged by the vacuum. Specifically, the intensity of the vacuum may be 0.1 MPa to 0.6 MPa. For example, the intensity of the vacuum may be 0.5 MPa.

On the other hand, when the light sintering is performed, the sintering temperature can be controlled by applying heat to the upper and lower portions of the printed circuit board 100. For example, a heating plate (not shown) and a cooling plate (not shown) of the vacuum-heating plate can control the temperature of the printed circuit board 100. For example, the lower portion of the printed circuit board 100 may be heated using the heating plate. Accordingly, it is possible to solve the problem that the sintering can not be performed due to insufficient heat reaching to the lower portion of the printed circuit board 100.

The temperature of the printed circuit board 100 may be increased by the preliminary light irradiation lamp 313 of the extreme ultraviolet light output unit 300.

Referring to FIG. 2D, the photo-sintered circuit pattern 101 is again moved in the A direction by the substrate transferring units 210 and 211 to perform continuous photo-sintering of the printed circuit board 100 .

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms.

Each of the embodiments described below performs photo-sintering with a light sintering apparatus according to an embodiment of the present invention, that is, a light-sintering apparatus having a vacuum-heating plate, an optical wavelength filter, and a far ultraviolet ray output unit, Conditions, and the like.

Example  1: vacuum-heating plate, optical wavelength filter and Far-ultraviolet  Performing photo-sintering with a light sintering device with an output section introduced (1)

First, a solution of polyvinylpyrrolidone (MW 55,000) in a solvent mixture of DEG (Diethylene glycol) and DGBE (Diethylene glycol butyl ether) was dissolved in a weight ratio of 2 and dispersed using a sonicator. Copper nanoparticles (Tekna , diameter: 100 nm) was added so as to be 75 parts by weight of the total ink, followed by dispersion using a 3-roll mill to prepare a conductive copper ink.

The prepared conductive copper ink was printed on a polyimide substrate (PI, thickness: 50 μm) in the form of an electrode at a speed of 100 mm / s using a screen printer, and then the printed pattern was dried using infrared rays at a temperature of 110 ° C. Thereby completing an electrode pattern.

Thereafter, extreme ultraviolet white light was irradiated onto the dried pattern using a xenon flash lamp. The pattern was fixed at 0.5 MPa using a vacuum hole, and the temperature of the pattern was heated to 200 DEG C using a thermal plate. The light intensity of the ultraviolet light was 8 J / cm ² , the number of pulses was 1, the irradiation time was 5 ms, the wavelength of the light passing through 500 to 600 nm was applied, and the intensity of the far ultraviolet light was 10 mW / cm < ^{2 &} gt ;.

Example  2: vacuum-heating plate, optical wavelength filter and Far-ultraviolet  (2) Performing photo-sintering with a light sintering apparatus in which an output section is introduced.

Except that silicon wafers (Si wafers) were used instead of polyimide as the substrate and the intensity was 50 J / cm ² , the number of pulses was 30, and the irradiation time was 1 ms in the extreme white light irradiation conditions Was sintered in the same manner as in Example 1 described above.

Comparative Example 1: Performing photo-sintering with a vacuum-heating plate, a light wavelength filter, and a light sintering apparatus in which a far-ultraviolet output unit was not introduced (1)

After printing on a polyimide substrate using the conductive copper ink of Example 1 described above, an electrode pattern was formed by drying using infrared rays at 100 ° C.

Subsequently, the pattern was irradiated with extreme ultraviolet-white light, and the sintering was performed under the irradiation conditions under the conditions of the intensity of 8 J / cm ² , the number of pulses once, and the irradiation time of 5 ms.

However, vacuum-heating plate, far ultraviolet irradiation and optical wavelength filter were not applied.

Comparative Example 2: Performing photo-sintering with a vacuum-heating plate, a light wavelength filter, and a light sintering apparatus not having a far ultraviolet output section (2)

Sintering was carried out in the same manner as in Comparative Example 1, except that a silicon wafer (Si wafer) was used instead of polyimide as the substrate.

Table 1 below shows the results of measuring the resistance after sintering and the uniformity of resistance after sintering according to the sintering conditions of each example. In each of the embodiments, the conductive copper ink was used as a printing pattern. Thus, in Examples 1 to 4 except for the comparative examples, the extreme ultraviolet light was filtered by the optical wavelength filter in the wavelength band of 500 nm to 600 nm. Note that the light irradiation conditions described in the following table, that is, the number of pulses, the irradiation intensity, the irradiation interval, and the like, are conditions used in accordance with the type of the substrate.

Referring to Table 1, it can be seen that, in Examples 1 to 4, the resistance uniformity after sintering is as high as 95% or more regardless of the type of the substrate. It can be seen that the uniformity of the resistance after the photo-sintering is increased when the far ultraviolet ray output portion, the vacuum-heating plate and the optical wavelength filter of the light sintering apparatus according to the present invention are applied.

3 is an image of a scanning electron microscope observing the surface of a photo-sintered printed circuit board according to an embodiment of the present invention.

Referring to FIG. 3, it can be seen that the copper substrate photo-sintered according to the first embodiment of the present invention is highly uniformly sintered.

Experimental examples to be described later are examples for measuring the effects of the structures of the light sintering apparatus according to Example 1, that is, optical wavelength filters, far ultraviolet rays, vacuum-heating plates and via-hole masking apparatuses.

<Experimental Example 1>

Optical wavelength filter and Far-ultraviolet  Comparison of resistivity value of substrate with application

Light sintering was performed by the method of Example 1 described above,

Experiments were carried out in the case where both the optical wavelength filter and the deep ultraviolet light were applied, the optical wavelength filter was used alone, and the optical wavelength filter and the deep ultraviolet light were not applied. Then, in each case, the resistivity value of the printed circuit board was measured.

4 is a graph showing the result of sintering according to Experimental Example 1 of the present invention.

Referring to FIG. 4, when the optical wavelength filter and the far-ultraviolet light are both applied, the specific resistance value is as low as 12 μΩ · cm. However, when the optical wavelength filter and the far ultraviolet ray are not applied, the specific resistance value is 32 μΩ · cm, which is about three times higher.

That is, an effect of improving electric conductivity of the printed circuit board can be obtained by performing combined irradiation of ultraviolet white light and far ultraviolet light whose wavelength band is filtered by the optical wavelength filter.

<Experimental Example 2>

Comparing the bending degree of the substrate with the vacuum intensity of the vacuum hole of the vacuum-heating plate

Light sintering was performed by the method of Example 1 described above,

Vacuum intensities of 0.2 MPa, 0.5 MPa and 0.8 MPa through vacuum holes of the vacuum-heating plate were varied as experimental groups. After the light sintering was performed in the case of not applying vacuum as a control group, the degree of warpage of the printed circuit board Respectively.

The degree of bending of the substrate was measured as the width of the substrate folded when wrinkling occurred on the substrate.

FIG. 5 is a graph comparing the degree of warping of the substrate according to Experimental Example 2 of the present invention.

Referring to FIG. 5, when vacuum is not applied, it can be seen that the width of the substrate to be folded is 1.2 mm longest. On the contrary, when the vacuum intensity is 0.5 MPa, the width of the substrate that is folded is 0.3 mm, which is the shortest.

<Experimental Example 3>

Comparing the bending degree of the substrate with the heating temperature by the hot plate of the vacuum-heating plate

Light sintering was performed by the method of Example 1 described above,

As a test group, heat was applied to the lower part of the printed circuit board using a thermal plate of the vacuum-heating plate, and sintering was performed at different temperatures of 100 ° C, 200 ° C and 300 ° C. As a control group, And the printed circuit board was sintered. Next, the degree of bending of the substrate was measured in the same manner as in Experimental Example 2 described above.

FIG. 6 is an image comparing the degree of bending of the substrate according to Experimental Example 3 of the present invention.

Referring to FIG. 6, it can be seen that when the heat is not applied as in the control group, the width of the substrate to be folded is 1.6 mm, which is the longest. On the contrary, when the heating temperature is 200 ° C, it can be seen that the width of the substrate to be folded is the shortest at 0.3 mm.

<Experimental Example 4>

Spare Light irradiation  Comparing the bending degree of the substrate with the heating of the substrate by the lamp

The light sintering was performed by the method of Experimental Example 3 described above,

As a test group, heat was applied to the lower part of the printed circuit board using a preliminary light irradiation lamp instead of the thermal plate of the vacuum-heating plate, temperatures were changed to 100 ° C, 200 ° C and 300 ° C, And then kept at room temperature, followed by photo-sintering. Next, the degree of bending of the substrate was measured in the same manner as in Experimental Example 2 described above.

<Experimental Example 5>

Via -hall Masking  Sintering of printed circuit boards using devices

Light sintering was performed in the same manner as in Example 1 except for the following features.

The printed circuit board was sintered individually by dividing the printed circuit pattern part and the via hole into the printed circuit pattern part and the via hole simultaneously.

In the sintering of the circuit portion, the light intensity was 6 J / cm ² , the number of pulses was 1, the irradiation time was 5 ms, and the optical wavelength filter passing 500 to 600 nm and the intensity of the far ultraviolet light proceeded to 5 mW / cm ² Respectively.

On the other hand, in order to sinter the via hole portion, a masking device through which light is transmitted only through the via hole portion was irradiated, then the intensity was 20 J / cm ² under the irradiation condition, the number of pulses was 10, the irradiation time was 1 ms, And the intensity of the deep ultraviolet light was 5 mW / cm ² .

&Lt; Comparative Example 5-1 >

Via -hall Masking  Sintering of unused printed circuit boards

Light sintering was performed in the same manner as in Experimental Example 5, except for the following features.

Light sintering was performed at the same time without dividing the printed circuit pattern portion and the via hole. The light intensity was 20 J / cm ² under the light irradiation condition, the number of pulses was 10, the irradiation time was 1 ms, the pulse interval was 15 ms, the application of the optical wavelength filter passing through 500 nm to 600 nm and the intensity of the deep ultraviolet light were 5 mW / cm ²

&Lt; Comparative Example 5-2 &

Via -hall Masking  Sintering of unused printed circuit boards

Light sintering was carried out in the same manner as in Comparative Example 5-1 except that the light irradiation conditions were an intensity of 6 J / cm ² , a pulse number of once, an irradiation time of 5 ms, and an optical wavelength filter passing through 500 to 600 nm And the intensity of the far ultraviolet ray was 5 mW / cm ² .

Table 2 below shows the results of sintering according to Experimental Example 5 and Comparative Examples 5-1 and 5-2 described above.

Referring to Table 2, in the case of Comparative Example 5-1, when a higher energy was applied than in Comparative Example 5-2, the circuit portion and the via-hole portion were burned out and resistance was not formed. In the case of Comparative Example 5-2, a resistance of 0.033 Ohm / sq was formed only in the circuit portion, but not in the via-hole portion.

In Experimental Example 5, that is, when the circuit portion and the via-hole portion were separately sintered using the via-hole masking apparatus with different light irradiation conditions, it was confirmed that resistance was formed in each of the circuit portion and the via hole portion .

That is, in the case of the via-hole, since the thickness of the ink is as thick as the thickness of the substrate, a higher intensity of light energy than the circuit portion is required. In the multilayer printed circuit board, the sintering efficiency of each of the via-holes and the printed circuit pattern can be further improved by setting different light irradiation conditions in sintering the via-holes and the printed circuit pattern. In other words, by sintering individually through the masking device capable of transmitting light only in the via-holes, sintering of the printed circuit board can be made without damaging the ink or the substrate.

7A and 7B are photographs showing patterns of the printed circuit board according to Comparative Example 1 and Example 1, respectively.

Referring to FIG. 7A, it can be seen that the sintering of the substrate after sintering was markedly prominent when the sintering was performed only by a white light irradiation apparatus to which a vacuum-heating plate, a deep ultraviolet ray and an optical wavelength filter were not applied. In addition, in the case of Comparative Example 1, it can be confirmed that sintering of the entire substrate is not uniform, and portions not sintered and undersized portions are generated.

Referring to FIG. 7B, it can be seen that in the case of the first embodiment of the present invention, a high-quality printed circuit board can be obtained which not only uniformly sinters the substrate but also has high conductivity and no warping.

It should be noted that the embodiments of the present invention disclosed in the present specification and drawings are only illustrative of specific examples for the purpose of understanding and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

100: (Print) circuit board
100 ': substrate warpage (substrate wrinkle)
101, 102b, 102e: Circuit pattern
102b: first circuit pattern 102e: second circuit pattern
102: via-hole structure 102a: base layer
102c: insulating layer 102d: via-hole
200: vacuum-heating plate 210, 211: substrate transfer part
220: lower guide rail 221: upper guide rail
300: optical output unit 310: extreme-wave white-light output unit
311: Beam guide 312: Main illumination lamp
313: preliminary light irradiation lamp 320: far ultraviolet ray output section
400: optical wavelength filter 410: reflector

Claims (17)

A vacuum hole for applying a vacuum to fix the printed circuit board; A vacuum-heating plate including a heat plate for heating or cooling the printed circuit board;
A light output unit positioned above the vacuum-heating plate and optically sintering the printed circuit board by irradiating light; And
And a substrate transfer unit positioned at one side of the vacuum-heating plate and transferring the printed circuit board in one direction,
Wherein the light output portion includes upper guide rails provided on side surfaces facing each other, and the vacuum-heating plate includes lower guide rails provided on the side surfaces facing each other,
Wherein the guide rails are arranged to face each other with the printed circuit board interposed therebetween when the light output portion moves downward. The method according to claim 1,
Wherein the optical output unit is connected to a vertically moving unit that allows upward and downward movement of the optical output unit at an upper portion of the printed circuit board, and the optical output unit moves downward in the direction of the printed circuit board during photo-sintering. delete The method according to claim 1,
Wherein the light output portion includes upper guide rails provided on two pairs of side faces facing each other, wherein the vacuum-heating plate includes lower guide rails provided on two pairs of side faces facing each other, And are arranged to face each other with the printed circuit board interposed therebetween when moving downward. 5. The method of claim 4,
Wherein the guide rails are rotatable, wherein when the light output portion moves downward, the upper guide rails and the lower guide rails rotate in the outward direction from the central portion of the vacuum-heating plate, respectively, Device. The method according to claim 1,
Wherein the light output unit includes an extreme ultraviolet wave output unit and a far ultraviolet ray output unit located on one side of the extreme ultraviolet ray output unit and irradiates the extreme ultraviolet ray and the far ultraviolet ray simultaneously or sequentially. The method according to claim 6,
Wherein the extreme ultraviolet wave output unit comprises:
At least one extreme wave white light lamp;
A reflector disposed on the lamp and reflecting the light;
A beam guide disposed under the lamp to adjust an optical path; And
And a light wavelength filter disposed inside the beam guide for adjusting a wavelength band of light. 8. The method of claim 7,
The optical wavelength filter adjusts the wavelength of the light to 300 to 700 nm,
And the optical sintering is performed by simultaneously applying the optical wavelength filter and the far ultraviolet ray output unit. 8. The method of claim 7,
In the extreme ultraviolet wave lamp,
The present irradiation lamp and the preliminary light irradiation lamp,
Wherein the preliminary light irradiation lamp is irradiated with light first than the main illumination lamp and irradiates light having a lower intensity than light emitted from the main illumination lamp. The method according to claim 1,
Wherein a plurality of vacuum holes are arranged in the vacuum-heating plate, vacuum is applied to a lower portion of the printed circuit board, the diameter of the holes is 100 to 1 mm, and the intervals of the holes are 1 to 5 cm. . 11. The method of claim 10,
And the intensity of the vacuum is 0.1 MPa to 0.6 MPa. The method according to claim 1,
Wherein the temperature of the printed circuit board is controlled by the vacuum-heating plate from -50 ° C to 300 ° C. 13. The method of claim 12,
Wherein the temperature of the substrate is controlled by the heating plate of the vacuum-heating plate to 100 ° C to 300 ° C. The method according to claim 1,
Wherein the substrate transfer unit is in the form of a roll positioned on both sides of the vacuum-heating plate to move the printed circuit board in one direction, or in the form of a conveyor belt positioned below the printed circuit board and rotating by itself. The method according to claim 1,
Wherein the printed circuit board comprises a conductive metal ink or a conductive metal paste pattern. The method according to claim 1,
Wherein the printed circuit board includes a multilayer circuit pattern and a via-hole. 17. The method of claim 16,
And a masking device for passing light through the via-hole before the circuit pattern, when performing the photo-sintering of the printed circuit board including the multilayer circuit pattern and the via-hole, .

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