KR20180090953A - electromagnetic wave shield coating method - Google Patents

Abstract

The present invention relates to an electromagnetic wave shielding coating method, comprising: a loading step of attaching one surface of the electronic element to a transport carrier; a dipping step of dipping the electronic element attached to the transport carrier in a receiving tank containing metal ink to apply metal ink to an exposed outer surface of the electronic element; a firing step of curing the metal ink applied to the electronic element; and an unloading step of separating the electronic element from the transfer carrier. According to the present invention, an electromagnetic wave shielding film having a uniform thickness is formed on the surface of the electronic element by dipping the surface of the electronic element into metal ink, thereby providing an electromagnetic wave shielding effect in a simplified process.

Description

[0001] Electromagnetic wave shield coating method [0002]

The present invention relates to an electromagnetic wave shielding coating method, and more particularly, to an electromagnetic wave shielding coating method characterized by forming an electromagnetic wave shielding film on the surface of an electronic device by dipping the surface of the electronic device into metal ink.

Recently, the rapid development of the electrical and electronic industry and information and communication technology has provided many convenience and luster to human life. However, in addition to these advantages, there are various side effects, one of which is the harmfulness of electromagnetic waves generated from this. Electromagnetic waves generated from household electrical appliances, information communication appliances and industrial appliances are emerging as new environmental problems due to electromagnetic interference (EMI) and harmfulness to the human body. In addition, as the speeding up of electronic and information communication devices and the widening of their bandwidths are accelerated, not only information communication devices such as mobile phones, notebook computers, personal digital assistants (PDAs) and personal digital assistants Therefore, it is urgent to develop the technology to solve the EMI problem.

In general, a semiconductor chip fabricated in a packaging process step during a semiconductor device fabrication process is molded with an insulating resin to protect the semiconductor chip from the external environment. When a completed electronic device is operated, electromagnetic waves are generated here or, conversely, There is a concern that an error may occur due to the influence of the influence of the electronic device, thereby causing serious defects of the electronic device.

As another proposal for solving this, there is a method of forming an electromagnetic wave shielding film on the surface of the electronic element or the resin molding outside surface by dry or wet method.

As a dry method, a method of forming an electromagnetic wave shielding film by a sputtering method is widely used. In the case of the sputtering method, the sputtering equipment is not only expensive but also has a disadvantage of being inefficient because it must be sputtered for a long time. In addition, due to the characteristics of the sputtering process, it is difficult to form a metal layer with a uniform thickness on the upper and side surfaces, and a mechanical process means is additionally required to compensate for the disadvantage. In order to solve the above problems, a method and an apparatus for forming a uniform electromagnetic wave shielding film on the upper and side surfaces are disclosed in Korean Patent Publication No. KR 10-1686318 B1 (2016.12.07).

As a wet method, a spray method is common and relatively superior in productivity compared to the sputtering method. However, since the spraying on the entire surface of the electronic device, especially on the side of the electronic device, is not easy structurally, Causing waste and polluting the semiconductor clean room. Also, like the above-described sputtering process, it is difficult to apply a metal layer having a uniform thickness for forming an electromagnetic wave shielding film on the top and side surfaces in the spraying process.

In addition, there is a plating method, but since the plating method has weak adhesion between the metal layer and the resin, Korean Patent Registration No. 10-0839930 (Jun. 20, 2008) discloses a separate pretreatment step for generating roughness have. However, the plating solution used in the plating process has disadvantages in that it must be managed and treated with great care in terms of environmental safety.

It is most important to form an electromagnetic wave shielding film only in a necessary shielding area except the mounting surface (PCB surface) of the entire surface of the electronic device. In the above sputtering method, spraying method, and plating method, there is a problem that a metal shielding film is formed to an area where electromagnetic shielding is not required Occurs. In order to prevent this, it is possible to mask a mounting surface that does not require shielding by using, for example, an adhesive tape. As a metal shielding film is coated on the adhesive tape, a crack occurs in the metal shielding film when the electronic device is unloaded An electromagnetic shielding function can not be performed at all. Therefore, in order to prevent such defects, an additional precutting process is required.

KR 10-1686318 B1 2016.12.07. KR 10-0839930 B1 2008.06.20.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an electromagnetic wave shielding coating method capable of forming an electromagnetic wave shielding film having a uniform thickness on a surface of an electronic device by dipping the exposed surface of the electronic device into metal ink .

According to another aspect of the present invention, there is provided a method of manufacturing an electronic device, comprising the steps of: attaching one surface of an electronic device to a transporting carrier; dipping the electronic device attached to the transporting carrier into a receiving tank containing metal ink, A dipping step of applying a metal ink to the outer surface of the electronic element; a firing step of curing the metal ink applied to the electronic element; And an unloading step of separating the electronic element from the transport carrier.

Here, it is preferable to perform a surface treatment step for imparting hydrophilicity to the exposed surface of the electronic element attached to the transfer carrier, prior to the dipping step.

In addition, the surface treatment step preferably plasma-processes the surface of the electronic device.

In addition, it is preferable that the surface of the transfer carrier on which the electronic element is mounted has hydrophobicity.

Further, it is preferable to further perform a leveling step of making the coating thickness of the metallic ink applied to the surface of the electronic element constant before the firing step.

Preferably, the leveling step scatters the metal ink over-coated on the surface of the electronic element with a blade in the dipping step to flatten the ink level.

In the leveling step, it is preferable that the metal ink over-coating the surface of the electronic element in the dipping step is absorbed by the blade made of the absorbing material and leveled flat.

In the dipping step, it is preferable to control the dipping depth of the electronic device in accordance with the specification of the electronic device attached to the carrier.

In addition, it is preferable that the water level of the metal ink is selectively adjusted to a depth equal to or lower than the thickness of the electronic device.

In addition, it is preferable that the transporting carrier comprises a carrier film which is transported in a roll-to-roll manner, and a bonding portion capable of attaching one surface of the electronic device to the one side of the carrier film.

In the dipping step, it is preferable that the dipping depth of the electronic device is controlled by pressing the back surface of the conveyance carrier, to which the electronic device is attached, using the dipping roller which is controlled to be elevated above the receiving tank.

In the dipping step, it is preferable that the metal ink is applied to the outer surface of the electronic element moving on the upper side of the dipping roller while the dipping roller absorbing the metal ink of the receiving tank rotates.

According to the present invention, an electromagnetic wave shielding film having a uniform thickness is formed on the surface of an electronic device by dipping the surface of the electronic device into metal ink, thereby providing an excellent electromagnetic wave shielding effect in a simplified process.

Further, in the case of forming the electromagnetic wave shielding film by the conventional sputtering method, an additional step of removing the electromagnetic wave shielding film formed in the unnecessary area after sputtering is indispensable. In this process, a crack is generated in the electromagnetic wave shielding film, It is possible to prevent the formation of an electromagnetic wave shielding film in an unnecessary portion by forming an electromagnetic wave shielding film by dipping the exposed surface of the electronic device into the metallic ink after attaching the mounting surface of the electronic device to the adhesion portion of the carrier, Accordingly, it is possible to omit an additional step of removing a part of the conventional electromagnetic wave shielding film, and it is also possible to prevent cracking of the electromagnetic wave shielding film.

1 is a flow chart of a process of an electromagnetic wave shielding coating method according to a first embodiment of the present invention,
FIG. 2 is a process chart for each process step of FIG. 1,
Fig. 3 is an enlarged view of the receiving tank shown in Fig. 2,
4 is a process diagram showing a modification of the dipping step of the electromagnetic wave shielding coating method according to the first embodiment of the present invention,
5 is a process diagram of an electromagnetic wave shielding coating method according to a second embodiment of the present invention,
6 is a process diagram of an electromagnetic wave shielding coating method according to a third embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an electromagnetic wave shielding coating method according to a first embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a process flow chart of an electromagnetic wave shielding coating method according to a first embodiment of the present invention, FIG. 2 is a process diagram of the process steps of FIG. 1, and FIG. 3 is an enlarged view of the receptacle shown in FIG.

1, the electromagnetic shielding coating method according to the first embodiment includes a loading step S10, a dipping step S20, a leveling step S30, a firing step S40, and an unloading step S50 .

In the present embodiment, the transporting carrier 10 moves in the lateral direction and proceeds for each process, for example.

2 (a), the mounting surface (PCB surface) of the electronic element D is brought into close contact with the bonding portion 11 of the transporting carrier 10, Thereby attaching the electronic element D to the adhering portion 11 of the transporting carrier 10. Meanwhile, a surface treatment step for imparting hydrophilicity to the outer surface of the electronic device (D) can be performed. In this surface treatment step, the surface of the electronic device (D) The adhesion of the metal ink M can be increased.

The dipping step S20 moves the transporting carrier 10 to the upper region of the receiving tank 20 containing the metal ink M and feeds The transfer carrier 10 is placed in the receiving chamber 20 in a state in which the electronic element D attached to the adhering portion 11 of the carrier 10 is positioned to face the receiving chamber 20 located in the lower region of the conveying carrier 10. [ , The electronic element D is dipped in the metallic ink M.

Here, the dipping is performed only in the essential shielding region of the electronic device D, and specific examples thereof include a case where an electromagnetic shielding (electromagnetic shielding) is applied to an EMC (Epoxy Molding Compound) The water level d2 of the metallic ink M accumulated in the tank 20 is set to be lower than the side height d1 of the electronic element D as shown in FIG. 2 (b) It is possible to form an electromagnetic wave shielding film having a uniform thickness by dipping only the upper surface and the side surface portions of the ink D onto the metallic ink M. [

As described above, it is most important to form an electromagnetic wave shielding film only in the essential shielding area except for the mounting surface of the entire surface of the electronic device D. In a known technique such as a sputtering method and a spraying method, the electronic device D, It is not easy to form a uniform electromagnetic wave shielding film on the side surface of the electromagnetic shielding film and a separate masking process is required for protection of the mounting surface and a separate process for preventing cracking of the electromagnetic wave shielding film in the unloading process must be performed.

However, according to the present embodiment, when the mounting surface of the electronic element D is adhered to the bonding portion 11 of the conveyance carrier 10, the opposite surface (upper surface) Since it is inverted and then dipped, the metal ink (M) can be applied only to the essential shielding region. Particularly, in this embodiment, since the mounting surface of the electronic element D, which is a problem in the related art, is not adhered to the bonding portion 11 of the transporting carrier 10 and is not exposed, the metallic ink M is prevented from being applied to the mounting surface And the metal ink M is applied all the way to the side of the electronic element D, so that an electromagnetic shielding film of uniform thickness can be provided. Therefore, since an electromagnetic wave shielding film is not formed in an unnecessary area as in the prior art, there is no need for an additional step for removing the electromagnetic wave shielding film, and cracks in the electromagnetic wave shielding layer, which may occur in such a removing step, It is possible to prevent a scene from being contaminated by a metal for forming an electromagnetic wave shielding film.

3, the water level of the metal ink M required for dipping the electronic element D is maintained. Therefore, the water level adjusting means . More specifically, the water level d2 of the metallic ink M accumulated in the receiving tank 20 should be equal to or lower than the side height d1 of the electronic element D, It is preferable that the water level of the water level M can be adjusted. In order to precisely control the level of the metal ink M in the holding tank 20, a water level sensor 21 is provided to supplement the metal ink M constantly as much as the amount of the metal ink M, The water level sensor 21 may be a laser type, an ultrasonic type, a magnetostrictive type, a frequency type, or a floating type sensor. In addition to these sensors, various types of sensors capable of measuring the level of the metallic ink M in the receiving tank 20 can also be used.

At least one of the height adjusting device of the electronic device D and the height adjusting device of the receiving tank 20 during dipping may be used to precisely control the uniformity of the electromagnetic wave shielding film, .

A diaphragm pump, a tube pump, a piston pump, and a gear pump can be used as the supplying means 22 for supplying the metal ink M. In addition, various kinds of metal ink M It is also possible to use the pump of FIG. When the metal ink M stored in the water reservoir 20 overflows, the water level sensor 21 senses the water level of the metal ink M, and the interval between the water level sensor 20 and the electronic element D Or the height of the sidewall of the receiving tank 20 may be adjusted to be lower than the height of the side surface of the electronic device D so that the excess metal ink M can be drained. The excess metal ink M drained at this time can be stored in the storage tank 23 and then supplied to the receiving tank 20 through the feeding means 22 again.

The metal ink M used in the dipping step S20 may be any metal ink M containing a conductive metal. For example, a metal ink M containing conductive metal particles, a non-particle type metal ink M, (M) are applicable, but are not limited thereto.

As the metal ink M, a metal having conductivity can be used in various ways. For example, a silver ink containing silver (Ag) can be used. In the case of silver, a metal capable of providing an excellent electromagnetic wave shielding effect Therefore, it is preferable to use silver ink, but it is not necessarily limited to ink. A binder, a crosslinking agent, a reducing agent, a surfactant, a wetting agent, a thixotropic agent or a leveling agent, a thickening agent, a surfactant, , An antifoaming agent, and the like.

The viscosity of the metal ink (M) composition of the present invention is preferably 1 to 50,000 cPs, and more preferably 5 to 400 cPs. If the viscosity value is too low, the flowability is increased, and it is difficult to form a uniform electromagnetic shielding film on the top and side surfaces of the electronic device D. If the viscosity is too high, the flowability is excessively reduced, and the thickness of the electromagnetic shielding film becomes uneven, Poor electrical conductivity, adhesion properties and appearance problems occur.

In addition, the surface tension of the metallic ink M can be adjusted to obtain a uniform electromagnetic shielding film on the top, side, and curved portions of the electronic device D. The surface tension of the metal ink (M) is preferably at most 35 dyn / cm, more preferably at most 30 dyn / cm. When the surface tension of the metal ink M is high, ink is deposited on the upper and side surfaces due to the wettability of the metal ink M on the surface of the electronic element D, and the coating is thinned at the bent portions, A defect may occur. This defect can be solved by repeating the dipping step S20 several times, but it is natural that the number of the dipping step S20 must be minimized in terms of production efficiency.

 In addition, in order to exhibit the shielding property of the electromagnetic wave shielding film, the electromagnetic wave shielding film formed of the metal ink M of this embodiment preferably has an electrical characteristic of 800 Ω / □ or less at the maximum. When the electrical conductivity is low, the thickness of the electromagnetic wave shielding film is thickened to secure necessary electromagnetic wave shielding characteristics, which may adversely affect the light and short cut of the electronic device D.

The electronic element D is lifted upward from the receptacle 20 and the electronic element D is moved from the metallic ink M of the receptacle 20 to the electronic element D as shown in Figure 2 (c) .

Through the dipping step (S20), the metal ink (M) can be applied to the upper surface and the side surface portion of the entire surface of the electronic element (D) which require electromagnetic shielding. When the electronic element D is dipped and drawn to the bottom surface of the receiving tank 20 after the level of the metal ink M accommodated in the receiving tank 20 is set in accordance with the height required for shielding the electromagnetic wave, There is an advantage that the electromagnetic wave shielding film can be formed only at a constant height up to the side height of the electronic device D which is required.

In the leveling step S30, as shown in FIG. 2 (d), in order to prevent the metal ink M applied on the surface of the electronic element D from being burnt, It is possible to perform the operation of flattening by removing the metal ink (M). For example, when the blade 30 and the electronic element D are moved relative to each other while the blade 30 made of a material having a predetermined hardness is disposed at a position spaced apart from the upper surface of the electronic element D by a predetermined distance, The blade 30 can scrape off the metal ink M applied to the electronic element D and planarize it. It is also possible to prevent the metal ink M from being burnt by absorbing a certain amount of the metallic ink M applied to the surface of the electronic element D by using the blade 30 made of an absorbing material such as a porous material. As the absorbent material such as porous material, for example, sponge, EVA foam, or urethane foam may be used. In addition, various porous absorbent materials may be used.

In the firing step (S40), the electronic element (D) is heated and fired in a state in which the metallic ink (M) is coated on the surface of the electronic element (D).

The sintering step (S40) may include a first sintering step and a second sintering step. The first sintering is preliminary sintering. The conditions may vary depending on the kind of the electronic element (D) and the use environment, As shown in FIGS. 2 (d) and 2 (e), while providing thermal energy to the electronic element D coated with the metallic ink M through the primary heater 41, . The main purpose of the first firing step is to maintain the uniformity until the second firing step is reached by minimizing or eliminating the flowability of the metal ink (M) uniformly applied to the surface of the electronic element (D). In the second firing step, firing can be performed at 150 ° C for 5 minutes through the secondary heater 42, but the firing conditions are not limited thereto.

2 (f), the unloading step S50 separates the electronic element D from the adhering portion 11 of the transporting carrier 10, An electromagnetic wave shielding film is formed by applying and firing the metallic ink (M) only on the upper surface and the side surface.

In the meantime, it is preferable that the adhesive portion 11 used in the present embodiment maintains the adhesive force while proceeding to the dipping step S20, but loses the adhesive force or has a weak adhesive force before proceeding to the unloading step S50. It is a matter of course that the contamination of the mounting surface of the electronic element D in the unloading step (S50) causes a product failure, and therefore no transition of the adhesive material from the bonding portion 11 is required. It is also possible to use an ultraviolet (UV) curing tape to lose the adhesive force of the electronic element D, more preferably to use a foam tape, or to use a tape which can selectively lose the adhesive force. On the other hand, in the case of the adhering portion 11 which maintains a level of adhesion force which is not difficult in the process of attaching the electronic element D to the tape and forming the electromagnetic wave shielding film with the metal ink M and then separating the electromagnetic shielding film from the adhering portion 11, It is not necessary that the adhesive force is changed before and after the step S20.

4, the level d2 of the metal ink M accumulated in the receiving tank 20 is set equal to the side height d1 of the electronic element D, It is preferable to selectively perform the hydrophobic treatment on the surface of the bonding portion 11. [ The metal ink M is sandwiched between the mounting portion of the electronic element D and the adhering portion 11 by using the difference in characteristics between the surface of the hydrophilic-treated electronic element D and the surface of the hydrophobic- It is possible to form an electromagnetic wave shielding film in a non-permeable state. In order to impart hydrophobicity, the bonding portion 11 may include a hydrophobic material such as Teflon or silicone, or may be surface treated using the hydrophobic material, and it is also possible to use a micro projection having a nano meter size.

As described above, according to this embodiment, since the surface of the electronic device D can be dipped in the metal ink M to form the electromagnetic wave shielding film on the top and side surfaces of the electronic device D, . ≪ / RTI >

A separate protective coating layer may be formed on the electromagnetic wave shielding film for the purpose of protecting the electromagnetic wave shielding film formed according to need from the external environment. As the protective coating layer, it is preferable to use a polymer resin composition such as a thermosetting resin or a UV curing resin. When silver (Ag) is used as a metal material of an electromagnetic wave shielding film, it is possible to add a color for the purpose of raising the recognition rate or improving the appearance quality in the semiconductor inspection process, Compounds, carboxylic acid compounds or silane-based compounds. As a method of forming the above-described protective coating layer, it is preferable to use a process of coating and curing by using a dipping process like the above-described metal ink (M).

As described above, according to the present embodiment, the surface of the electronic device D is dipped in the metal ink M to form an electromagnetic wave shielding film and a protective coating layer, if necessary, on the surface of the electronic device D, Effect can be provided.

Next, a description will be given of an electromagnetic wave shielding coating method according to a second embodiment of the present invention with reference to the accompanying drawings.

5 is a process diagram of an electromagnetic wave shielding coating method according to a second embodiment of the present invention.

As shown in FIG. 5, the electromagnetic wave shielding coating method according to the second embodiment can be indirectly dipped using the dipping roller 24 having a porous moisture absorption structure, unlike the first embodiment.

The transporting carrier 10 is composed of a carrier film provided with a bonding portion on one surface thereof and wound in a roll shape. In the process of being transported in a roll-to-roll manner, a loading step S10, a dipping step S20 ), The sintering step (S40), and the unloading step (S50) are performed one after another, which is advantageous to the continuous process.

Specifically, in the loading step (S10), the mounting surface of the electronic element (D) is brought into close contact with the transfer carrier (10).

The electronic element D attached to the transporting carrier 10 through the loading step S10 is moved to the dipping step S20 while moving along the roll-to-roll line, and in the dipping step S20, The attached electronic element D is brought into contact with the dipping roller 24. At this time, the dipping roller 24 is made of a porous moisture absorbing structure and is pre-dipped in the metal ink M of the receiving tank 20 to fade sufficient metal ink M, The application of the metal ink M to the upper surface and the side surface of the electronic device D that require electromagnetic shielding by the rotating dipping roller 24 can be performed simultaneously. In this case, it is preferable that the dipping roller 24 is made of urethane foam, silicone foam or rubber foam. In addition, the metal ink M is easily transferred, and the metal ink M is deposited on the upper surface and the side surface of the electronic element D, It is of course possible to use a material having a modulus of elasticity necessary for coating. The distance between the dipping roller 24 and the electronic device D may be adjusted according to the standard of the electronic device D. For this purpose, And the roller supporting the back surface can be vertically adjustable in position.

The electronic element D having completed the application of the metallic ink M proceeds to the next firing step S40 through the roll-to-roll line. In the firing step S40, preliminary firing and final firing can be performed through the primary heater 41 and the secondary heater 42. When the metal ink M is completely cured by the firing step S40, An electromagnetic wave shielding film is formed on the upper surface and the side surface of the element D and then separated from the conveying carrier 10 through the unloading step S50.

On the other hand, in the case of dipping indirectly using the dipping roller 24 as in the second embodiment, the coating amount of the metallic ink M applied to the surface of the electronic element D through the dipping roller 24 is The leveling step in the first embodiment for partially removing the metal ink M applied to the surface of the electronic element D may be omitted.

Next, the electromagnetic wave shielding coating method according to the third embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 6, the electromagnetic wave shielding coating method according to the third embodiment includes a roll-to-roll process, unlike the first embodiment.

For this purpose, the transporting carrier 10 is composed of a carrier film having a bonding portion provided on one surface thereof and wound in a roll shape. In the course of transporting in a roll-to-roll manner, the loading step S10, the surface treatment step, the dipping step S20, Since the leveling step S30, the firing step S40, and the unloading step S50 are performed in order, it is advantageous for the continuous process.

6, the electronic element D attached to the transporting carrier 10 through the loading step S10 is moved to the dipping step S20 while moving along the roll-to-roll line, and the dipping step S20 The back surface of the transporting carrier 10 to which the electronic element D is attached is pressed by the pressure roller 25 and dipped in the metal ink M of the receiving tank 20. [

Since the angle of entry of the electronic device D into the receiving chamber 20 can be adjusted by using angle rolls disposed on both sides of the pressing roller 25, It is possible to maximize the uniformity of the metallic ink M to be formed. Here, when the entry angle of the electronic device D is excessively larger than horizontal, the height of the side coating at a portion contacting with the bottom of the receiving tank 20 and the side contacting the bottom may not be constant at the time of entry of the electronic device D If the angle of entry is too low, only a part of the side surface of the electronic device D may be coated to form an electromagnetic shielding film in a necessary portion.

Thereafter, the electronic element D fed in the roll-to-roll manner is drawn out from the metal ink M of the receiving tank 20 while being separated from the section pressed by the pressure roller 25 toward the receiving tank 20 . At this time, the water level in the water level sensor 21 is preferably provided in the water level sensor 20 because the level of the water level in the water level sensor 20 must be maintained as described above. Further, it is possible to further improve the dipping efficiency by providing vibration means for providing ultrasonic vibration to the receiving tank 20, and by controlling the flowability of the metallic ink M by disposing irregularities on the bottom of the receiving tank 20, It is possible to improve the characteristics. That is, when the uniformity of the metal ink (M) is high, it is difficult to uniformly coat the metal ink (M), the flow resistance of the metal ink (M) A uniform coating can be induced.

Through the dipping step (S20), the application of the metal ink (M) to the upper surface and the side surface of the entire surface of the electronic device (D) requiring electromagnetic shielding exposed to the outside is completed.

In the continuous process according to the roll to roll transfer mode, the electronic device D is drawn out from the receiving tank 20, moves through the roll-to-roll line, and enters the leveling step S30.

In this leveling step S30, in order to prevent the metal ink M applied on the surface of the electronic element D from being burnt in the continuous process in which the electronic element D moves on the roll-to- A leveling operation is performed to scrape off the excessively applied metal ink M with the blade 30 to flatten it.

Here, it is described that the leveling is performed using the bar-shaped blade 30 spaced apart from the electronic element D at a predetermined interval. However, it is possible to flatten the metal ink M by removing a part of the over- As another example, the blade 30 may be made of a porous absorbing material to absorb the metal ink M poured onto the surface of the electronic element D to prevent the ink from being burnt .

When the leveling step S30 is completed, the next firing step S40 is performed through the roll-to-roll line. In the firing step S40, preliminary firing and final firing can be performed through the primary heater 41 and the secondary heater 42. In this firing step S40, the metal ink (for example, The electromagnetic shielding film is formed on the upper surface and the side surface of the electronic device D and then the electronic device D on which the electromagnetic shielding film is formed is separated from the conveying carrier 10 through the unloading step S50 do.

As described above, according to the present invention, the electromagnetic wave shielding film is formed by dipping the surface of the electronic device D in the metallic ink M, thereby providing an excellent electromagnetic wave shielding effect in a simplified process.

Hereinafter, the constitution and effects of the present invention will be described in more detail through examples. These embodiments are only for illustrating the present invention, and the scope of the present invention is not limited by these embodiments.

≪ Measurement of physical properties &

The surface resistance of the ink-coated surface was measured using a 4-point probe. The viscosity was measured at 20 rpm at 25 ° C using a Brookfield viscometer using 0.5 ml of ink. The surface tension was measured using K20 (Easy dyne ).

The dispersion particle size was measured by diluting 10% of the ink in the butylcarbitol solvent using dynamic light scattering

The coating thickness was measured by FE-SEM and the electromagnetic shielding test was measured by the electromagnetic wave shielding performance (S21 Parameter, ASTM D4935).

≪ Preparation of ink for electromagnetic shielding coating >

 [Production Example 1] Production of Ag ink in the form of particles

A mixture of 100 g of Ag 2-ethylhexylcarbamate and 100 g of a solvent (Butanol 100 g, Isobutylamine 50 g), a dispersant (BYK 145145, 1 g), an epoxy resin (0.5 g), a wetting agent , 0.05 g) were mixed to prepare a particulate Ag ink having a viscosity of 5 cps, a surface tension of 23 dyne / cm, and a sheet resistance of 650 m? / Sq.

[Production Example 2] Production of metal ink in the form of particles

A mixture of 100 g of Ag 2-ethylhexylcarbamate, 20 g of anisole, 40 g of 2-ethylhexylamine, 40 g of a dispersant (BYK 145, 0.5 g), epoxy resin (0.3 g), wetting agent (antittera 204, (EFKA 350, 0.05 g) were mixed to prepare a particulate Ag ink having a viscosity of 38 cps, a surface tension of 29 dyne / cm and a sheet resistance of 300 m? / Sq.

[Manufacturing Example 3] Production of nano-particle dispersion type metal ink

40 g of Ag nanoparticles were mixed with a solvent (butyl carbitol 60 g), a dispersant (BYK 145, 4 g), a stabilizer (Ethyl cellulose, 2 g) and a binder resin (Cellulose acetate butyrate, 1 g) Mixed and reacted uniformly for 6 h.

After the reaction was completed, the beads were removed with a filter to obtain an ink in which Ag nanoparticles were dispersed uniformly. Ink having a viscosity of 50 cps, a surface tension of 26 dyne / cm and a sheet resistance of 90 m?

[Manufacturing Example 4] Production of nano-particle dispersion type metal ink

40 g of Ag nanoparticles were mixed with 500 ml of a solvent (propylene glycol monomethyl ether acetate, 50 g), a dispersant (BYK 330, 5 g), a stabilizer (Ethyl cellulose, 2 g) and a binder resin (Polyvinyl butyral, Were mixed and reacted uniformly for 6 h. After the completion of the reaction, the beads were removed with a filter to obtain an ink in which Ag nanoparticles were dispersed uniformly. Ink having a viscosity of 400 cps, a surface tension of 35 dyne / cm and a sheet resistance of 50 m?

[Production Example 5] Production of paste-type metal ink

After mixing Ag powder (40g), epoxy resin (10g), adhesion promoter (BYK 4510, 0.3g), fumed silica (0.05g) and solvent (butyl carbitol, 0.5g) roll mill to prepare a paste ink having a viscosity of 50,000 cps and a sheet resistance of 60 m? / ?.

<Electromagnetic wave shielding coating process>

[Example 1]

Five surfaces of the semiconductor package except the lower surface of the six sides of the semiconductor package were coated through the vertical dipping process of the first embodiment using the viscosity 5 cps non-particulate metal ink of [Manufacturing Example 1], followed by baking Thereby forming an electromagnetic wave shielding film.

The thus formed shielding film has a sheet resistance of 700 mΩ / □, a step coverage of 93%, a shielding rate of 32 dB

[Example 2]

The non-particulate metal ink having a viscosity of 38 cps in [Preparation Example 2] was used to coat the remaining five surfaces of the semiconductor package except the lower surface of the semiconductor package through the vertical dipping process of the first embodiment, followed by pre- And 150 DEG C for 5 minutes to form an electromagnetic wave shielding film. The thus formed shielding film has a sheet resistance of 350 mΩ / □, a step coverage of 95%, and a shielding ratio of 42 dB.

[Example 3]

Using the viscosity 50 cps nano-particle dispersion type metal ink of [Manufacturing Example 3], the remaining five sides of the semiconductor package except for the bottom of the six sides of the semiconductor package were coated through the vertical dipping process of the first embodiment, Followed by baking to form an electromagnetic wave shielding film.

The thus formed shielding film has a sheet resistance of 100 mΩ / □, a step coverage of 94%, and a shielding ratio of 50 dB.

[Example 4]

Using the viscosity 400 cps Ag nano-particle dispersion type ink of [Manufacturing Example 4], the remaining five sides of the semiconductor package except for the bottom of the six sides of the semiconductor package were coated through the vertical dipping process of the first embodiment, To form an electromagnetic wave shielding film.

The thus formed shielding film has a sheet resistance of 55 mΩ / □, a step coverage of 95%, and a shielding rate of 61 dB.

[Example 5]

Using the Ag paste type metal ink having the viscosity of 50,000 cps as in [Manufacturing Example 5], the remaining five surfaces except for the bottom of the six surfaces of the semiconductor package were coated through the vertical dipping process of the first embodiment, To form an electromagnetic wave shielding film.

The thus formed shielding film has a sheet resistance of 65 mΩ / □, a step coverage of 95%, and a shielding ratio of 57 dB.

[Example 6]

The non-particulate metal ink having viscosity of 5 cps in [Preparation Example 1] was used to coat the remaining five surfaces of the semiconductor package except for the bottom surface of the semiconductor package through the indirect dipping process of the second embodiment, followed by pre- And 150 DEG C for 5 minutes to form an electromagnetic wave shielding film.

The sheet resistance of this formed shield is 750mΩ / □, step coverage is 90%, shielding rate is 30dB.

[Example 7]

Using the viscosity 38 cps non-particulate metal ink of [Manufacturing Example 2], the remaining five surfaces of the semiconductor package except for the bottom surface of the semiconductor package were coated through the indirect dipping process of the second embodiment, followed by baking Thereby forming an electromagnetic wave shielding film.

The thus formed shielding film has a sheet resistance of 400 mΩ / □, a step coverage of 92%, and a shielding rate of 40 dB.

[Example 8]

Using the viscosity 50 cps nano-particle dispersion type ink of [Manufacturing Example 3], the remaining five sides of the semiconductor package except for the bottom of the six sides of the semiconductor package were coated through the indirect dipping process of the second embodiment, Thereby forming an electromagnetic wave shielding film through firing.

The thus formed shielding film has a sheet resistance of 150 mΩ / □, a step coverage of 91%, and a shielding rate of 48 dB.

[Example 9]

Using the viscosity 400 cps Ag nano-particle dispersion type ink of [Manufacturing Example 4], the remaining five sides of the semiconductor package except for the bottom of the six sides of the semiconductor package were coated through the indirect dipping process of the second embodiment, Thereby forming an electromagnetic wave shielding film through firing.

The sheet resistance of this formed shield is 57mΩ / □, step coverage is 93%, shielding rate is 61dB.

[Example 10]

Using the Ag paste type metal ink having a viscosity of 50,000 cps as in [Manufacturing Example 5], the remaining five surfaces except for the bottom of the six surfaces of the semiconductor package were coated through the indirect dipping process of the second embodiment, Thereby forming an electromagnetic wave shielding film through firing.

The thus formed shielding film has a sheet resistance of 70 mΩ / □, a step coverage of 92%, and a shielding ratio of 56 dB.

[Example 11]

The non-particulate metal ink having a viscosity of 5 cps in [Manufacturing Example 1] was used to coat the remaining five surfaces of the semiconductor package except for the bottom surface of the semiconductor package through the roll-to-roll dipping process of the third embodiment, Thereby forming an electromagnetic wave shielding film through firing. The thus formed shielding film has a sheet resistance of 650 mΩ / □, a step coverage of 95%, and a shielding ratio of 34 dB.

[Example 12]

Using the viscosity 38 cps non-particulate metal ink of [Manufacturing Example 2], the remaining five surfaces of the semiconductor package except for the bottom surface of the semiconductor package were coated through the roll-to-roll dipping process of the third embodiment, Preliminary firing, and final firing at 150 DEG C for 5 minutes to form an electromagnetic wave shielding film. The thus formed shielding film has a sheet resistance of 300 mΩ / □, a step coverage of 96%, and a shielding ratio of 43 dB.

[Example 13]

Using the viscosity 50 cps nano-particle dispersion type ink of [Manufacturing Example 3], the remaining five surfaces of the semiconductor package except for the bottom surface of the semiconductor package were coated through the roll-to-roll dipping process of the third embodiment, An electromagnetic wave shielding film is formed through firing for 10 minutes.

The thus formed shielding film has a sheet resistance of 90 mΩ / □, a step coverage of 97%, and a shielding rate of 52 dB.

[Example 14]

Using the viscosity 400 cps Ag nano-particle dispersion type ink of [Manufacturing Example 4], the remaining five surfaces of the semiconductor package except for the bottom surface of the semiconductor package were coated through the roll-to-roll dipping process of the third embodiment, , And an electromagnetic wave shielding film is formed through firing for 15 minutes.

The thus formed shielding film has a sheet resistance of 50 mΩ / □, a step coverage of 96%, and a shielding rate of 65 dB.

[Example 15]

Using the Ag paste type metal ink having a viscosity of 50,000 cps as in [Manufacturing Example 5], the remaining five surfaces of the semiconductor package except for the bottom surface of the semiconductor package were coated through the roll to roll dipping process of the third embodiment, , And fired for 20 minutes to form an electromagnetic wave shielding film.

The sheet resistance of this formed shield is 60m Ω / □, step coverage is 96%, shielding rate is 59dB.

&Lt; Electromagnetic wave shielding film protective coating >

[Example 19]

The upper surface of the electromagnetic wave shielding film prepared in [Example] was coated with thermosetting resin through the roll-to-roll dipping process of the third embodiment except for the bottom surface of the six sides of the semiconductor package, and then baked To form a protective coating layer.

[Example 20]

The upper surface of the electromagnetic wave shielding film prepared in [Example] was coated with UV curing resin on the remaining five surfaces except for the bottom surface of the six sides of the semiconductor package through the Roll to Roll dipping process of the third embodiment, .

<Comparative Example of Electromagnetic Wave Shielding Coating Process>

[Comparative Example 1] / Sputtering process

Sputtering Apparatus Using a DC magnetron sputtering apparatus, a metal sintered body was formed as a sputtering target. The deposition conditions were room temperature, DC 500 W, oxygen concentration of 6%, and annealing conditions at 300 캜 for 1 hour in an atmospheric environment. The SUS / CU / SUS multi-layered shielding film was formed by sputtering the target module on the top and side surfaces by adjusting the sputtering angle so that the five surfaces except the surface provided with the solder balls could be coated.

The step coverage of this formed shield is 41%.

[Comparative Example 2] / spraying process

The viscosity 50 cps nanoparticle dispersed ink of [Manufacturing Example 3] was spray coated on the top and side surfaces of the semiconductor package using a spray device (787 MS-SS valve), and then fired for 10 minutes at 130 ° C. Thereby forming a shielding film. The step coverage of this formed shield is 47%.

&Lt; Physical property measurement result >

The characteristics of the produced electromagnetic wave shielding ink are shown in Table 1 below.

Ink type Non-particle type Ag ink Nano particle dispersion type
Ag Ink Paste type
ink Manufacturing example Production Example 1 Production Example 2 Production Example 3 Production Example 4 Production Example 5 Viscosity
(cps) 5 38 50 400 50,000 Surface tension
(dyne / cm) 23 29 26 35 - Sheet resistance
(mΩ / □) 650 300 90 50 60

Table 2 shows the characteristics of the electromagnetic wave shielding film formed according to each of the electromagnetic wave shielding dipping processes manufactured in the examples.

Characteristics of electromagnetic shielding film according to dipping process and ink type First Embodiment
Vertical dipping [Example 1]
/ Production example 1 [Example 2]
/ Production example 2 [Example 3]
/ Production example 3 [Example 4]
/ Production example 4 [Example 5]
/ Production example 5 Sheet resistance
(mΩ / □) 700 350 100 55 65 Step coverage
(%) 93 95 94 95 95 Shielding rate
(dB) 32 42 50 61 57 Second Embodiment
Indirect dipping [Example 6]
/ Production example 1 [Example 7]
/ Production example 2 [Example 8]
/ Production example 3 [Example 9]
/ Production example 4 [Example 10]
/ Production example 5 Sheet resistance
(mΩ / □) 750 400 150 57 70 Step coverage
(%) 90 92 91 93 92 Shielding rate
(dB) 30 40 48 61 56 Third Embodiment
Roll to Roll dippings [Example 11]
/ Production example 1 [Example 12]
/ Production example 2 [Example 13]
/ Production example 3 [Example 14]
/ Production example 4 [Example 15]
/ Production example 5 Sheet resistance
(mΩ / □) 650 300 90 50 60 step coverage
(%) 95 96 97 96 96 Shielding rate
(dB) 34 43 52 65 59

Comparison of Step Coverage of Coating Film by Electromagnetic Shielding Process [Example 13] [Comparative Example 1] [Comparative Example 2] fair Roll to Roll
Dipping Sputter Spray coating
thickness
(um) Top surface 1.8 4.1 3.15 side 1.75 1.7 1.5 step coverage
(%) 97 41 47 image

The scope of the present invention is not limited to the above-described embodiments, but may be embodied in various forms of embodiments within the scope of the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.

10: transfer carrier, 11: adhesive portion, 20: receiving container,
21: water level sensor, 22: supplying means, 23: storage tank,
24: dipping roller, 25: pressure roller, 30: blade,
41: preliminary dryer, 42: final dryer, D: electronic device,
M: metal ink, P: plasma,
S10: loading, S20: dipping, S30: leveling,
S40: firing step, S50: unloading step

Claims (12)

A loading step of attaching one surface of the electronic device to the transfer carrier;
A dipping step of dipping the electronic element attached to the transporting carrier into a receiving tank containing metal ink to apply metal ink to the exposed outer surface of the electronic element;
A firing step of curing the metal ink applied to the electronic element; And
And an unloading step of separating the electronic element from the transporting carrier. The method according to claim 1,
And a surface treatment step of imparting hydrophilicity to the exposed surface of the electronic device prior to the dipping step. 3. The method of claim 2,
Wherein the surface treatment step is a step of plasma-treating the surface of the electronic device. 3. The method of claim 2,
Wherein an electronic element mounting surface of the carrier is hydrophobic. The method according to claim 1,
And a leveling step of uniformly applying a thickness of the metallic ink applied to the surface of the electronic element before the firing step. 6. The method of claim 5,
Wherein the leveling step scatters the metal ink over coated on the surface of the electronic element with a blade to flatten the surface of the electronic element in the dipping step. 6. The method of claim 5,
Wherein the leveling step absorbs the metal ink excessively applied to the surface of the electronic element in a dipping step with a blade made of an absorbing material and leveling the metal ink flatly. The method according to claim 1,
Wherein the dipping step controls the dipping depth of the electronic device according to the specification of the electronic device attached to the transport carrier. 9. The method of claim 8,
Wherein the water level of the metal ink is adjusted to a depth equal to or lower than the thickness of the electronic device. The method according to claim 1,
Wherein the carrier is made of a carrier film that is transported in a roll-to-roll manner, and a bonding portion capable of attaching one surface of the electronic device is provided on one side of the carrier film. 11. The method of claim 10,
Wherein the dipping step controls the dipping depth of the electronic device by pressing the back surface of the transporting carrier to which the electronic device is attached using a dipping roller controlled to be lifted and lowered from above the receiving tank toward the receiving tank. 11. The method of claim 10,
Wherein the dipping step comprises coating the metal ink on the outer surface of the electronic element moving on the upper side of the dipping roller while rotating the dipping roller absorbing the metal ink of the receiving tank.

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