JP2023136661A - Method for forming conductive layer, conductive layer, electronic module, and electronic apparatus - Google Patents

Abstract

To efficiently form shield layers 250, 260 on a top face 102 and a side face 104 of a substrate 100.SOLUTION: A method for forming a shield layer 200 includes: a first application step of applying, by an ink jet head 400, an ink 500 including conductive material 520 to a top face 102 of a substrate 100; and a second application step of applying, by the ink jet head 400, the ink 500 to a side face 104 of the substrate 100.SELECTED DRAWING: Figure 8

Description

The present invention relates to a method for forming a conductive layer, a conductive layer, an electronic module, and an electronic device.

Patent Document 1 discloses, in a semiconductor integrated circuit mounted on a printed circuit board on which a wiring pattern is formed and connected to the wiring pattern via a plurality of terminals, a surface of the semiconductor integrated circuit on the opposite side of the printed circuit board. A semiconductor device having an electromagnetic noise shielding part, characterized in that it has a shielding part that shields electromagnetic noise, and a connecting part for connecting the shielding part and the ground on the printed circuit board. Integrated circuits are described.

Patent Document 2 describes an EMI shield in which the conductive layer includes inkjet printing.

Japanese Patent Application Publication No. 2001-127211 US Patent No. 9282630

An object of the present invention is to efficiently form a conductive layer.

The method for forming a conductive layer according to claim 1 of the present invention includes a first application step of applying a liquid composition containing a conductive material to the upper surface of an object by an application part, and a applying part to a side surface of the object. and a second applying step of applying the liquid composition.

According to claim 1 of the present invention, a conductive layer can be efficiently formed.

FIG. 1 is an explanatory diagram of an electronic device according to an embodiment of the present invention. FIG. 3 is an explanatory diagram of another electronic device according to the present embodiment. FIG. 3 is an explanatory diagram of a method for forming an electromagnetic shield according to the present embodiment. FIG. 7 is another explanatory diagram of the method for forming the electromagnetic shield according to the present embodiment. It is an explanatory view in the middle of formation of an electromagnetic wave shield concerning this embodiment. It is an explanatory view after formation of an electromagnetic wave shield concerning this embodiment. It is another explanatory view in the middle of formation of the electromagnetic wave shield based on this embodiment. It is another explanatory view after formation of the electromagnetic wave shield based on this embodiment. It is an explanatory view of a formation process of an electromagnetic wave shield concerning this embodiment. FIG. 2 is an explanatory diagram of an electromagnetic shield according to an example of the present embodiment.

Printed wiring boards (PWBs) used in high-speed communications such as 5G and autonomous driving, which do not have electronic components attached to them, now operate as electronic circuits with electronic components soldered to them. Printed circuit boards (PCBs) in the state of the art are required to have high reliability, and control technology using electromagnetic waves generated from electronic components and wiring is known. Furthermore, as products become smaller and lighter, PCBs and the like are required to be thinner and lighter, and techniques for electromagnetic shielding of PCBs and electronic components used in PCBs are also known.

In other words, as electromagnetic shielding for electronic components and electronic devices such as IC chips, capacitors, resistors, diodes, solenoids, and semiconductor packages, they may be covered with shielding films, metal caps, conductive materials such as conductive paint, or electromagnetic wave absorbers. It is being said.

FIG. 1 is an explanatory diagram of an electronic device according to an embodiment of the present invention.

As shown in FIG. 1A, the electronic device 1 includes a shield layer 200 and a protective layer 300 on a base material 100 formed on the outer peripheral surface of a semiconductor package 110. The shield layer 200 is electrically connected to a ground portion 100G included in the semiconductor package 110. The protective layer 300 may be omitted or may be formed integrally with the shield layer 200.

As shown in FIG. 1B, in this embodiment, the inkjet head 400 discharges ink 500 containing a conductive material onto the surface of the base material 100 disposed on the outer peripheral surface of the semiconductor package 110. A shield layer 200 is formed on the surface of the material 100.

Here, the ink 500 is an example of a liquid composition containing a conductive material, and the inkjet head 400 is an example of an application unit that applies the liquid composition. Further, the shield layer 200 is an example of a conductive layer.

FIG. 2 is an explanatory diagram of another electronic device according to this embodiment.

As shown in FIG. 2(a), the electronic device 1 includes an electronic component 120 and a board 130. The connection portion 125 provided on the electronic component 120 is electrically connected to the wiring 135 provided on the substrate 130 by attaching the electronic component 120 to the substrate 130.

The electronic component 120 includes a shield layer 200 on the base material 100 formed on the outer peripheral surface, and when the electronic component 120 is attached to the substrate 130, the shield layer 200 connects to the ground portion 100G provided on the substrate 130. Connect electrically. Electronic component 120 is an example of an electronic module.

As shown in FIG. 2B, in this embodiment, the inkjet head 400 discharges ink 500 containing a conductive material onto the surface of the base material 100 disposed on the outer peripheral surface of the electronic component 120. A shield layer 200 is formed on the surface of the material 100.

Although US Pat. No. 9,282,630 describes an EMI shield in which the conductive layer includes inkjet printing, there is no mention of efficiently forming the shield layer 200.

That is, as shown in FIGS. 1 and 2, the shield layer 200 needed to be formed on five surfaces of the base material 100: the top surface, the left and right side surfaces, and the front and rear sides.

The purpose of this embodiment is to efficiently form the shield layer 200 on the base material 100 having multiple surfaces.

FIG. 3 is an explanatory diagram of a method for forming an electromagnetic shield according to this embodiment.

As shown in FIG. 3A, the inkjet head 400 applies ink 500 to the upper surface 102 of the base material 100 placed on the mounting table 600, thereby forming the upper shield layer 250. This is an example of a first application step in which a liquid composition containing a conductive material is applied to the upper surface of the object by the application unit.

Next, the mounting table 600 is moved in the direction of the arrow in the figure. This is an example of a movement process in which the object and the application section are relatively moved in a direction intersecting the direction in which the application section applies the liquid composition.

Subsequently, as shown in FIG. 3(b), the inkjet head 400 applies ink 500 to the corner portion 106 of the base material 100 placed on the mounting table 600, thereby forming a side surface of the base material 100. Ink 500 is dropped onto the substrate 104 to form a side shield layer 260.

Here, the direction in which the inkjet head 400 discharges the ink 500 is the same in FIGS. 3(a) and 3(b).

Then, by rotating the mounting table 600 around the vertical axis in the figure, the inkjet head 400 sprays the ink 500 onto the other three sides 104 of the base material 100 placed on the mounting table 600. By applying this, shield layers 260 on the other three sides are formed.

FIG. 4 is another explanatory diagram of the method for forming the electromagnetic shield according to this embodiment.

The inkjet head 400 shown in FIG. 3 was arranged to eject the ink 500 in the normal direction of the top surface 102 of the base material 100, but the inkjet head 400 shown in FIG. The ink 500 is arranged to be ejected in a direction intersecting the side surface 104.

As shown in FIG. 4A, the inkjet head 400 applies ink 500 to the upper surface 102 of the base material 100 placed on the mounting table 600, thereby forming the upper shield layer 250.

Next, the mounting table 600 is moved in the direction of the arrow in the figure. This is an example of a movement process in which the object and the application section are relatively moved in a direction intersecting the direction in which the application section applies the liquid composition. The above is the same as in FIG. 3.

Subsequently, as shown in FIG. 4(b), the inkjet head 400 applies ink 500 to the corners 106 and side surfaces 104 of the base material 100 placed on the mounting table 600, thereby cleaning the side surfaces. A shield layer 260 is formed.

Here, the direction in which the inkjet head 400 discharges the ink 500 is the same in FIGS. 4(a) and 4(b).

Then, by rotating the mounting table 600 around the vertical axis in the figure, the inkjet head 400 sprays the ink 500 onto the other three sides 104 of the base material 100 placed on the mounting table 600. By applying this, shield layers 260 on the other three sides are formed.

As shown in FIGS. 3 and 4, in this embodiment, one can be moved by simply moving the mounting table 600 in the horizontal direction in the figure or rotating the mounting table 600 around an axis in the vertical direction in the figure. Using the inkjet head 400, the shield layer 200 can be formed on five surfaces of the base material 100: the top surface, left and right side surfaces, and front and rear side surfaces.

That is, the base material 100 is rotated so that the side surface 104 of the base material 100 faces upward, a separate inkjet head 400 is provided for each of the five surfaces of the base material 100, that is, the top surface, left and right sides, and front and rear sides. In this embodiment, the shield layer 200 can be formed more efficiently than when the orientation of the head 400 is changed.

Furthermore, when the inkjet head 400 is arranged as shown in FIG. can be formed into

Here, as shown in FIGS. 3 and 4, the thickness of the shield layer 250 on the top surface is almost uniform, but the shield layer 260 on the side surface 104 is formed by dropping the ink 500, so that the thickness of the shield layer 250 on the top surface is almost uniform. The bottom part is thicker than the other.

That is, the difference between the thickness of the shield layer 260 at one end of the side surface 104, which is an example of the first surface, and the thickness of the shield layer 260 at the other end opposite to the one end of the side surface 104 is an example of the second surface. The shield layer 260 is formed so as to be larger than the difference between the thickness of the shield layer 250 at one end of the upper surface 102 and the thickness of the shield layer 250 at the opposite end of the upper surface 102 .

FIG. 5 is an explanatory diagram during the formation of the electromagnetic shield according to this embodiment. 5(a) is a side view of the base material 100, and FIG. 5(b) is a sectional view taken along line AA in FIG. 5(a).

As shown in FIGS. 5A and 5B, an insulating material 510 is provided at the lower end of the side surface 104 of the base material 100, and the conductive material 520 discharged by the inkjet head is placed above the side surface 104. dripped from. The insulating material 510 is preferably applied by being ejected from an inkjet head, but may be applied by other methods. The insulating material 510 is a thermosetting and photocurable resin, and is an example of a convex portion formed on the surface of the side surface 104.

The insulating material 510 is preferably ink 500 applied by inkjet, such as Taiyo Ink IJSR-4000 or Goo Kagaku PR-1205, but any material having the functions of these inks may be used.

FIG. 6 is an explanatory diagram after forming the electromagnetic shield according to this embodiment. 6(a) is a side view of the base material 100, and FIG. 6(b) is a sectional view taken along line AA in FIG. 6(a).

As shown in FIGS. 6A and 6B, the insulating material 510 applied to the lower end of the side surface 104 of the base material 100 blocks the conductive material 520 dripped from above. As a result, the conductive material 520 is formed so that the lower part of the side surface 104 is thicker than the upper part.

As the ink 500 applied by inkjet, the conductive material 520 is preferably GenesInk Smart Jet I (S-CS01520) Ag particles, Bando Kagaku SR7000Ag particles, etc., but any material having the functions of these inks may be used.

Here, the insulating material 510 is provided with a gap that allows the conductive material 520 to pass through so that a portion of the conductive material 520 dropped from above reaches the ground portion 100G. Alternatively, the insulating material 510 may be provided to protrude into the ground portion 100G.

As described above, in this embodiment, by applying the insulating material 510 to the lower end of the side surface 104 of the base material 100, it is possible to suppress the conductive material 520 dropped onto the side surface 104 from flowing out before it hardens. , the side shield layer 260 can be reliably formed on the side surface 104 of the base material 100.

FIG. 7 is another explanatory diagram showing the electromagnetic shield according to the present embodiment being formed. 7(a) is a side view of the base material 100, and FIG. 7(b) is a sectional view taken along line AA in FIG. 7(a).

As shown in FIGS. 7A and 7B, an insulating material 510 is provided on the side surface 104 of the base material 100, and the conductive material 520 discharged by the inkjet head is dropped from above the side surface 104. Ru.

Unlike FIGS. 5 and 6, the insulating material 510 is applied to areas other than the lower end of the side surface 104 of the base material 100, but it is applied so that the density of the lower part of the side surface 104 is higher than that of the upper part. ing.

FIG. 8 is another explanatory diagram after the electromagnetic shield according to the present embodiment is formed. FIG. 8(a) is a side view of the base material 100, and FIG. 8(b) is a sectional view taken along line AA in FIG. 8(a).

As shown in FIGS. 8(a) and 8(b), the insulating material 510 applied to the side surface 104 of the base material 100 inhibits the flow of the conductive material 520 dropped from above. The conductive material 520 dripped from above is dammed up by the insulating material 510 applied to the lower end of the conductive material 104 .

As a result, the conductive material 520 is formed so that the lower part of the side surface 104 is thicker than the upper part.

Here, similarly to FIGS. 5 and 6, the insulating material 510 is provided with a gap through which the conductive material 520 can pass so that a portion of the conductive material 520 dropped from above reaches the ground portion 100G. Granted. Alternatively, the insulating material 510 may be provided to protrude into the ground portion 100G.

As described above, in this embodiment, by applying the insulating material 510 to the side surface 104 of the base material 100, the conductive material 520 dropped on the side surface 104 is suppressed from flowing out. Furthermore, by applying the insulating material 510 to the lower end of the side surface 104 of the base material 100 so that the density is higher in the lower part than in the upper part, it is ensured that the conductive material 520 dropped on the side surface 104 flows out. to be suppressed. Thereby, the side shield layer 260 can be reliably formed on the side surface 104 of the base material 100.

Note that the shield layer 250 on the upper surface 102 of the base material 100 does not need to contain the insulating material 510 because the conductive material 520 does not flow out unlike the side surface 104, but it may contain the insulating material 510 from the viewpoint of preventing oxidation. good. In that case, the density of the insulating material 510 within the shield layer 250 is preferably uniform.

FIG. 9 is an explanatory diagram of the process of forming the electromagnetic shield according to this embodiment.

First, the base material 100 is set as a work in an inkjet apparatus (step S1), and the work is cleaned (step S2). In the example of cleaning the work, air blow cleaning using air pressure was used, but adhesive roller cleaning using general organic solvents (alcohols, etc.) or adhesive, plasma cleaning, etc. may also be used.

Next, as explained in FIGS. 6 and 8, the ink 500 containing the insulating material 510 is applied to the side surface 104 of the base material 100 placed on the mounting table 600 (step S3 ), the insulating material 510 is cured by UV exposure (step S4).

In the example, IJSR4000IJ material manufactured by Taiyo Ink Manufacturing Co., Ltd. was used as the insulating material 510, and UV exposure was performed at a wavelength of 365 nm for 1 to 9 seconds.

Here, by repeating steps S3 and S4, the thickness of the insulating material 510 can be increased to a desired thickness.

Next, the film condition such as the coating position and film thickness of the insulating material 510 is inspected for appearance and film thickness (step S5), and the temperature of the mounting table 600 is raised to 30 to 200°C, preferably 130°C. (Step S6).

Then, as explained in FIGS. 3 and 4, the ink 500 containing the conductive material 520 is applied to the top surface 102 and side surface 104 of the base material 100 placed on the mounting table 600 using the inkjet head 400 ( Step S7), and thermally harden the conductive material 520 (Step S8).

In the example, an Ag material manufactured by ULVAC was used as the conductive material 520, and thermal curing was performed at 150° C. for 30 minutes.

Next, the appearance and film thickness of the conductive material 520 are inspected for the coating position, film thickness, and other film conditions (step S9).

FIG. 10 is an explanatory diagram of the electromagnetic shield according to the example of the present embodiment, and is a photograph showing the object whose coating state was observed in step S9 of FIG.

In the example, since the thickness of the insulating material 510 was generally thin, the surface of the side surface 260 of the shield layer was generally coated with the conductive material 520, and the boundary between the side surface 104 of the base material 100 and the ground portion 100G was In the vicinity, the insulating material 510 formed unevenness, so the conductive material 520 was blocked at this portion.

From this result, it was confirmed that it is possible to form the shield layer 200 on the side surface 104 of the base material 100 by optimizing the thickness of the insulating material 510 and the surface energy and discharge amount of the conductive material 520.

Furthermore, from the present results, it was confirmed that the conductive material 520 could be coated even when the surface of the workpiece was uneven.

●Summary●
As described above, the method for forming the shield layer 200 according to an embodiment of the present invention includes a first application step of applying ink 500 containing a conductive material 520 to the upper surface 102 of the base material 100 using the inkjet head 400. , a second application step of applying ink 500 to the side surface 104 of the base material 100 using the inkjet head 400. Preferably, between the first application step and the second application step, a movement step of relatively moving the base material 100 and the inkjet head 400 in a direction intersecting the direction in which the inkjet head 400 applies the ink 500 is included. include.

Here, the base material 100 is an example of an object, the shield layer is an example of a conductive layer, the inkjet head 400 is an example of an application section, and the ink 500 is an example of a liquid composition.

Thereby, the shield layers 250 and 260 can be efficiently formed on the top surface 102 and side surface 104 of the base material 100.

In the second application step, the inkjet head 400 applies ink in a direction intersecting the top surface 102 and side surfaces 104 of the base material 100. Thereby, the ink 500 can be ejected opposite the side surface 104 of the base material 100, so that the shield layer 260 can be reliably formed on the side surface 104 of the base material 100.

In the second application process, the direction in which the inkjet head 400 applies ink to the side surface 104 is the same as the direction in which the inkjet head 400 applies ink to the top surface 102 in the first application process.

Thereby, the shield layers 250 and 260 can be formed more efficiently than when the orientation of the inkjet head 400 is changed.

By the above-described formation method, the shield layer 260 formed on the side surface 104 is configured such that the lower part is thicker than the upper part.

The shield layer 260 formed on the side surface 104 includes an insulating material 510. Thereby, the conductive material 520 dropped on the side surface 104 can be prevented from flowing out before being hardened, and the shield layer 260 can be reliably formed on the side surface 104. The insulating material 510 is an example of a convex portion formed on the surface of the side surface 104 and a photocurable resin.

In the shield layer 260 formed on the side surface 104, the insulation material 510 has a higher density at the lower part than at the upper part. Thereby, it is possible to reliably prevent the conductive material 520 dropped onto the side surface 104 from flowing out before it hardens, and to form the shield layer 260 on the side surface 104 more reliably.

The method for forming the shield layer 200 includes a third application step of applying ink 500 containing an insulating material 510 to the side surface 104 using the inkjet head 400 before the first application step.

Thereby, the insulating material 510 can be applied to the side surface 104 before the ink 500 containing the conductive material 520 is applied by the inkjet head 400.

The shield layer 200 according to an embodiment of the present invention is a shield layer 200 formed on the top surface 102, which is an example of a first surface that intersects with each other, and the side surface 104, which is an example of a second surface, of the base material 100. Therefore, the difference between the thickness of the shield layer 260 at one end of the side surface 104 and the thickness of the shield layer 250 at one end of the side surface 104 is greater than the difference between the thickness of the shield layer 250 at one end of the upper surface 102 and the thickness of the shield layer 250 at the other end opposite to the one end of the upper surface 102. There is a large difference in thickness between the shield layer 260 at one end and the other end on the opposite side. Thereby, it is possible to obtain the shield layer 200 that is efficiently formed.

Further, the shield layer 200 according to an embodiment of the present invention is a shield layer 200 formed on the side surface 104, which is an example of the surface of the base material 100, and the thickness of the shield layer 260 at one end of the side surface 104 is as follows: The density of the insulating material 510 included in the shield layer 260 at one end of the side surface 104 is thicker than the thickness of the shield layer 260 at the other end opposite to the one end of the side surface 104. The density is greater than the density of the insulating material 510 included in the layer 260. Thereby, it is possible to obtain the shield layer 200 that is efficiently and reliably formed.

1 Electronic device 100 Base material 102 Top surface 104 Side surface 106 Corner portion 100G Ground portion 110 Semiconductor package 120 Electronic component 125 Connection portion 130 Substrate 135 Wiring 200 Shield layer (an example of a conductive layer)
250 Top surface 260 Side surface 300 Protective layer 400 Inkjet head (example of application part)
500 ink (an example of liquid composition)
510 Insulating material 520 Conductive material 600 Mounting table

Claims (15)

a first application step of applying a liquid composition containing a conductive material to the upper surface of the object by the application unit;
a second application step of applying the liquid composition to a side surface of the object using the application unit;
A method of forming a conductive layer comprising: between the first application step and the second application step, a moving step of relatively moving the object and the application section in a direction intersecting a direction in which the application section applies the liquid composition;
The method for forming a conductive layer according to claim 1, further comprising: In the second application step,
3. The method of forming a conductive layer according to claim 1, wherein the applying unit applies the liquid composition in a direction intersecting the upper surface and the side surface of the object. In the second application step, the direction in which the application section applies the liquid composition to the side surface is the same as the direction in which the application section applies the liquid composition to the top surface in the first application step. The method for forming a conductive layer according to any one of claims 1 to 3, wherein the method is the same as the above. 5. The method for forming a conductive layer according to claim 1, wherein the conductive layer formed on the side surface is thicker at a lower portion than at an upper portion. 6. The method for forming a conductive layer according to claim 1, wherein in the second application step, the application unit applies the liquid composition to the side surface on which a plurality of convex portions are formed. 7. The method of forming a conductive layer according to claim 6, wherein the convex portion is formed of a curable resin. 8. The method for forming a conductive layer according to claim 7, wherein the curable resin is cured by light. 9. The method for forming a conductive layer according to claim 6, wherein the plurality of convex portions are formed of an insulating material. 10. The method for forming a conductive layer according to claim 6, wherein the convex portion has a higher density at a lower portion than at an upper portion of the conductive layer formed on the side surface. Before the first application step,
The method for forming a conductive layer according to any one of claims 6 to 10, comprising a third applying step of applying a liquid composition to the side surface using a applying unit to form the plurality of convex portions. A conductive layer formed on a first surface and a second surface of the object that intersect with each other,
The difference between the thickness of the conductive layer at one end of the first surface and the thickness of the conductive layer at the other end of the first surface opposite to the one end,
The conductive layer has a large difference in thickness between the conductive layer at one end of the second surface and the other end of the second surface opposite to the one end. A conductive layer formed on the surface of an object,
The thickness of the conductive layer at one end of the surface is thicker than the thickness of the conductive layer at the other end opposite to the one end of the surface,
The density of the curable resin contained in the conductive layer at one end of the surface is higher than the density of the curable resin contained in the conductive layer at the other end opposite to the one end of the surface. An electronic module comprising the conductive layer according to claim 12 or 13. An electronic device comprising the conductive layer according to claim 12 or 13 or the electronic module according to claim 14.