KR101850204B1 - Multi-layer wiring board and method for manufacturing thereof - Google Patents

Abstract

The present invention relates to a multilayer wiring board in which wiring patterns and insulating layers are alternately laminated by an inkjet printing method and a method of manufacturing the multilayer wiring board and a multilayer wiring board comprising a substrate and an inkjet printing method using silver (Ag) An insulating layer formed on the one surface of the substrate by SU-8 ink by an inkjet printing method so that the first wiring pattern is covered so as not to be exposed to the outside; A multilayer wiring board comprising a second wiring pattern formed by an inkjet printing method with particle ink and a manufacturing method thereof are disclosed.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a multi-

The present invention relates to a multilayer wiring board and a method of manufacturing the same, and more particularly, to a multilayer wiring board in which wiring patterns and an insulating layer are alternately laminated by a non-contact printing method including inkjet and a method of manufacturing the multilayer wiring board.

As the size and weight of electronic devices and components are required to be reduced, it is also required to increase the density of wiring boards for mounting electronic components. In order to increase the density of the wiring board, a method of increasing the wiring density on the substrate and a method of laminating a plurality of wirings to form a multilayer structure are used.

In order to manufacture a wiring substrate of a multilayer structure, a so-called joining method in which wirings are formed on a plurality of substrates and these substrates are bonded together with an insulating sheet interposed therebetween and an insulating layer are laminated on a substrate on which wiring patterns are formed, A build-up method is known in which a multilayer structure is developed by repeating the process of forming a wiring pattern on the substrate.

The latter method is more advantageous for increasing the densification of the wiring board and widely used, for example, the same as that of Published Unexamined Patent Application No. 10-2014-0147894.

On the other hand, an inkjet printing method is often adopted to form a wiring pattern in a build-up method. The build-up method using this printing technology can reduce the size of the device by reducing the floor area occupied by wiring, electrodes, antenna coil, etc., and it is possible to integrate various devices on one substrate, so that it can be used as a base technology for manufacturing various devices. Do.

In order to manufacture a multilayer wiring board using an ink-jet printing method, a drop of a conductive material is dropped on a substrate or an insulating layer, which is a material of an insulating line, at regular intervals. These drops are left as discrete dots, The line is determined by physical properties such as the surface energy between the insulating material forming the insulating layer and the conductive material forming the inkjet droplet. Accordingly, it may be difficult to appropriately obtain the line width and thickness of the necessary wiring pattern depending on the physical characteristics between the two materials, which becomes a serious obstacle especially when forming a micrometer-scale wiring pattern. In addition, when the surface energy of the material forming the insulating layer is high, when the insulating layer is laminated again on the insulating layer, the spreadability is poor, and the insulating layer that is stacked does not completely cover the wiring pattern, so that the edge of the wiring may be short-circuited. On the other hand, there is a problem that one of the two materials is damaged due to mutual physical and chemical effects between the conductive material and the insulating material.

Published Japanese Patent Application No. 10-2014-0147894

SUMMARY OF THE INVENTION The present invention has been conceived to solve the problems described above, and it is an object of the present invention to provide a multilayer wiring board capable of adjusting the physical characteristics between materials for forming a wiring pattern and an insulating layer, And a method thereof.

Another object of the present invention is to provide a multilayer wiring board capable of suppressing damage to each material by minimizing physical and chemical influences between the conductive material and the insulating material and a method of manufacturing the same.

Other objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments with reference to the accompanying drawings.

In order to achieve the above object, a multilayer wiring board according to the present invention comprises a substrate, a first wiring pattern formed on the first surface of the substrate by an inkjet printing method with silver (Ag) nano-particle ink, An insulating layer formed on one surface of the substrate by a non-contact printing method with SU-8 ink so that the pattern is covered so as not to be exposed to the outside, and a second electrode formed on the outer surface of the insulating layer with silver nanoparticle ink by non- And a wiring pattern.

In the multilayer wiring board according to the present invention, the first wiring pattern and the second wiring pattern may be dried and baked. At this time, the first wiring pattern and the second wiring pattern may be dried at 50 ° C and baked at 200 ° C.

In the multilayer wiring board according to the present invention, the insulating layer may be baked, and the insulating layer may be baked at 200 ° C.

In the multilayer wiring board according to the present invention, the insulating layer may be treated with ultraviolet rays and ozone.

In the multilayer wiring board according to the present invention, the insulating layer and the second wiring pattern may be sequentially and repeatedly laminated.

A method for manufacturing a multilayer wiring board according to the present invention includes the steps of preparing a substrate made of an insulating material and forming a first wiring pattern by a non-contact printing method using silver (Ag) nanoparticle ink on one surface of the substrate A second printing step of forming an insulating layer by a non-contact printing method with SU-8 ink on one surface of the substrate so that the first wiring pattern is covered so as not to be exposed to the outside, And a third printing step of forming a second wiring pattern by an inkjet printing method with silver (Ag) nanoparticle ink.

In the method for manufacturing a multilayer wiring board according to the present invention, the method may further include a first baking step of drying and baking the first wiring pattern after the first printing step and before the second printing step. The first baking step may be performed at 50 < 0 > C and baked at 200 < 0 > C.

In the method for manufacturing a multilayer wiring board according to the present invention, the method may further include a second baking step of baking the insulating layer after the second printing step and before the third printing step. At this time, the second baking step may be baked at 200 degrees.

In the method for manufacturing a multilayer wiring board according to the present invention, the method may further include a surface treatment step of subjecting the insulating layer to ultraviolet rays and ozone treatment after the second printing step and before the third printing step.

In the method of manufacturing a multilayer wiring board according to the present invention, after the third printing step, the second printing step and the third printing step may be sequentially repeated.

Meanwhile, in the method for manufacturing a multilayer wiring board according to the present invention, the non-contact printing method may include at least one of ink jet, EHD jet, and nozzle jet.

According to the present invention, the spread of the silver nanoparticle ink can be obtained at a satisfactory level by controlling the surface energy of SU-8 in the process of forming the wiring pattern with the silver (Ag) nanoparticle ink on the insulating layer made of SU-8 . Similar results can be obtained with respect to spreadability between two insulating layers when the insulating layer is again laminated on the insulating layer.

In addition, when the insulating layer made of SU-8 is formed on the wiring pattern made of silver nanoparticles and the wiring pattern is sequentially formed on the insulating layer, the physical and chemical penetration between the two materials due to the influence of the drying degree, Damage to the pattern or insulating layer can be minimized.

The multilayer wiring board according to the present invention can be applied to an antenna coil for a smart label, an antenna coil for an RFID system, a flexible printed circuit board (FPCB), a printed electronic (wiring), Internet (IoT) It is big.

1 is a cross-sectional view of a multilayer wiring board according to an embodiment of the present invention.
2 is a flowchart of one embodiment of a method for manufacturing a multilayer wiring board according to the present invention.
Fig. 3 is a graph showing changes in contact angle, diameter, and linewidth of silver nanoparticle droplets according to the temperature for baking the SU-8 when ink-jet printing silver nano-particle ink on SU-8 in the embodiment of Fig. 2 to be.
Fig. 4 is an image showing a change in shape of an actual wiring pattern according to a temperature at which the SU-8 is baked when ink-jet printing silver nano-particle ink on SU-8 in the embodiment of Fig.
5 is a graph showing changes in the contact angle and linewidth of silver nanoparticle droplets with time for surface treatment of SU-8 when ink-jet printing silver nanoparticle ink on SU-8 in the embodiment of FIG. 2 .
Fig. 6 is an image showing the change in shape of an actual wiring pattern according to the time of surface treatment of SU-8 when ink-jet printing of silver nanoparticle ink on SU-8 in the embodiment of Fig.
7 is a graph showing a cross-sectional profile of an embodiment of a multilayer wiring board according to the present invention.
8 is an image of an actual cross-section of another embodiment of the multilayer wiring board according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of a multilayer wiring board and a manufacturing method thereof according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view of a multilayer wiring board according to an embodiment of the present invention, and FIG. 2 is a flowchart of an embodiment of a method for manufacturing a multilayer wiring board according to the present invention.

First, a substrate 10 to support other structures of the present invention is prepared (S10, substrate preparation step). The substrate 10 is made of an insulating material, and any suitable material can be selected and manufactured in a conventional manner, but silicon (Si) is preferably used as the main material.

The first wiring pattern 11 is printed by inkjet printing using silver nanoparticle ink on one surface (upper surface with reference to the drawing direction) of the substrate 10 (S20, first printing step). Inkjet printing means ejecting ink onto a substrate in a fine drop state. Thus, the silver nanoparticle ink should be in a liquid or fluid paste state. The first wiring pattern 11 thus formed becomes a conductive layer in the final product.

Since the silver nanoparticle ink printed in the first printing step S20 contains a liquid component, a drying process is required (S30, drying step). It is preferable that this drying step (30) is performed at 50 캜 for 30 minutes under the same condition as the experimental example described below.

On the other hand, in the course of the subsequent second printing step S30, the component of the SU-8 ink penetrates into the silver nanoparticle ink and may damage the first wiring pattern. For example, when SU-8 is mixed with silver nanoparticles, the electrical resistance is increased. Therefore, it is preferable to bake the first wiring pattern having undergone the drying step S30 at an appropriate temperature (S40, first baking step). It is preferable that the first baking step (S40) is performed at 200 DEG C for 30 minutes under the same condition as the experimental example described below. The first wiring pattern 11 having undergone the first baking step is cured, so that penetration by the SU-8 ink and thus damage of the first wiring pattern 11 can be minimized.

Thereafter, the insulating layer 21 is formed by applying the SU-8 ink, which is an insulating material, on the first wiring pattern 11 by the inkjet printing method. The first wiring pattern 11 is formed by the insulating layer 21 Is completely covered and is not exposed to the outside (S50, second printing step).

The SU-8 ink used in the second printing step (S50) also has fluidity and may be damaged by the silver nanoparticle ink depending on the interaction with the silver nanoparticle ink printed in the subsequent third printing step (S80) have. Therefore, the insulating layer 21 formed in the second printing step (S50) is baked and cured (S60, second baking step). It is preferable that the second baking step (S60) is performed at 200 DEG C for 30 minutes under the same conditions as the experimental example described below.

On the other hand, since the SU-8 ink has hydrophobicity, when the silver nanoparticle ink is printed on the insulating layer 21, the respective ink droplets may not be connected to each other. Even if they are connected to each other to form a line, May not be formed. This can be coped with by controlling the surface energy of the SU-8, so that the surface of the insulating layer 21 is subjected to surface treatment by irradiating ultraviolet rays (UV) and bringing them into contact with ozone (O ₃ ) (S 70, surface treatment step) . It is preferable that this surface treatment step (S70) is performed for 15 seconds under the same condition as the experimental example described below. Through this process, it is possible to modify from hydrophobic to hydrophilic by changing the surface energy of SU-8.

The second wiring pattern 12 is formed by inkjet printing of the silver nanoparticle ink on the insulating layer 21 having undergone the surface treatment step S70 (S80, third printing step). Thereby, a substrate in which the first wiring pattern 11 and the second wiring pattern 12 are formed in a multilayer with the insulating layer 21 therebetween can be obtained. Thereafter, the drying step (S30) to the third printing step (S80) are repeated in order to obtain a multilayer wiring board having three or more layers. For example, FIG. 1 illustrates a wiring board made of three layers by forming a second insulating layer 22 on the second wiring pattern 12 and a third wiring pattern 13 on the second insulating layer 22.

Hereinafter, a multilayer wiring board and a method of manufacturing the same according to the present invention will be described in detail with reference to specific experimental examples.

First, a silicon-based substrate, silver nanoparticle ink, and SU-8 ink are prepared. In this example, the silver nanoparticle ink is DGP 40LT-15C from ANP, the SU-8 ink is PriElex® SU-8 from MicroChem, and the inkjet printer is a Dimatix materials printer DMP-2381 from Fujifilm (cartridge DMP- The volume of the droplet to be printed is 10 pL. Meanwhile, in this ink-jet printer, the interval of each liquid droplet can be adjusted within a range of 5 to 40 mu m. In this experimental example, the nanoparticle ink is printed at an interval of 20 mu m and the SU-8 ink is printed at an interval of 5 mu m.

The SU-8 ink has hydrophobicity when fully cured, thereby impairing the spreadability of the silver nanoparticle ink printed thereon. In FIG. 3, the diameter of a single droplet of silver nanoparticle ink printed on the insulating layer, the calculated contact angle ), And the line width are sequentially plotted. According to this, the diameter of the silver nano-particle ink droplet does not change at 155 ° C or less, but rapidly increases at 156 ° C, then rapidly decreases at 157 ° C and becomes smaller at 155 ° C or less. The contact angle is calculated by a hemi-spherical model, which shows a generally opposite behavior to the diameter change. From these diameters and contact angle change graphs, it can be assumed that SU-8 has its surface properties changed from hydrophilic to hydrophobic near 156 ° C. As shown in the graph of the line width change, the line can not be formed at 157 ° C or more and the droplets of the silver nanoparticle ink remain intermittently. Such a change can also be confirmed from the actual photographed image in Fig.

On the other hand, it can be seen that the surface energy of SU-8 is influenced not only by the baking temperature but also by ultraviolet (UV) and ozone (O ₃ ) treatment. FIG. 5 is a table showing changes in calculated contact angle and line width of silver nano-particle ink applied on SU-8 according to UV / O ₃ treatment time. According to the results, as the UV / O ₃ treatment time becomes longer, the contact angle becomes smaller and the line width increases, so that the surface property of SU-8 is changed from hydrophobic to hydrophilic. Thus, an actual image of the silver nanoparticle ink printed on SU-8 is shown in Fig. In the state of no surface treatment, the droplets of the silver nanoparticle ink are intermittently arranged. However, when 15 seconds of the surface treatment are elapsed, they are connected to form a line having a line width of 76 m, The treatment took 45 seconds and the line width was 92 占 퐉. When the surface treatment was carried out for 60 seconds, the line width reached 140 占 퐉.

Fig. 7 is a diagram showing a cross-sectional profile of an example of the multilayer wiring board manufactured by the above-described experimental example. It should be noted that the scale of the lateral distance is different from the scale of the height. 8 is an actual sectional image of another example of the multilayer wiring board manufactured by the above experimental example. As described above, according to the present invention, it is possible to variously manufacture the thickness of the insulating layer and the thickness and width of the wiring pattern by controlling the hydrophobicity between the insulating layer and the conductive layer, respectively, while forming the insulating layer with the SU-8 ink and the conductive layer with the silver nanoparticle ink. .

Although the ink jet printing method has been described as an example of the printing method, any one or more of the non-contact printing methods such as EHD (Electrohydrodynamic) jet, nozzle jet, and the like may be applied.

The embodiments of the present invention described above and shown in the drawings should not be construed as limiting the technical idea of the present invention. The scope of protection of the present invention is limited only by the matters described in the claims, and those skilled in the art will be able to modify the technical idea of the present invention in various forms. Accordingly, such improvements and modifications will fall within the scope of the present invention as long as they are obvious to those skilled in the art.

Claims (16)

A substrate;
A first wiring pattern formed by a non-contact printing method using silver (Ag) nano-particle ink on one surface of the substrate,
An insulating layer formed on one surface of the substrate by a non-contact printing method with SU-8 ink so that the first wiring pattern is covered so as not to be exposed to the outside,
And a second wiring pattern formed on the outer surface of the insulating layer by a non-contact printing method using silver nanoparticle ink,
Wherein the insulating layer is baked at 200 DEG C and subjected to ultraviolet ray and ozone treatment for a time of 15 seconds or more and 60 seconds or less. The method according to claim 1,
Wherein the first wiring pattern and the second wiring pattern are dried and baked. 3. The method of claim 2,
Wherein the first wiring pattern and the second wiring pattern are dried at 50 캜 and baked at 200 캜. delete delete delete The method according to claim 1,
Wherein the insulating layer and the second wiring pattern are repeatedly laminated in order. A substrate preparation step of preparing a substrate made of an insulating material,
A first printing step of forming a first wiring pattern by a non-contact printing method using silver (Ag) nanoparticle ink on one surface of the substrate;
A second printing step of forming an insulating layer by non-contact printing with SU-8 ink on one surface of the substrate so that the first wiring pattern is covered so as not to be exposed to the outside,
And a third printing step of forming a second wiring pattern by a non-contact printing method using silver (Ag) nanoparticle ink on the outer surface of the insulating layer,
A second baking step of baking the insulating layer at 200 DEG C before the third printing step after the second printing step;
Further comprising a surface treatment step of subjecting the insulating layer to ultraviolet rays and ozone treatment for not less than 15 seconds and not longer than 60 seconds after the second printing step and before the third printing step. 9. The method of claim 8,
Further comprising a first baking step of drying and baking the first wiring pattern after the first printing step and before the second printing step. 10. The method of claim 9,
Wherein the first baking step comprises drying at 50 캜 and baking at 200 캜. delete delete delete 9. The method of claim 8,
Wherein the second printing step and the third printing step are sequentially repeated after the third printing step. 9. The method of claim 8,
Wherein the non-contact printing method includes at least one of ink jet, EHD jet, and nozzle jet. The method according to claim 1,
The non-contact printing method includes at least one of ink jet, EHD jet, and nozzle jet.

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