JP7436262B2 - Wiring printing head and wiring printing device - Google Patents

Description

The present invention relates to a wiring printing head and a wiring printing apparatus that apply droplets of wiring printing ink to an object to form a wiring pattern.

2. Description of the Related Art In recent years, a technique of printing wiring directly onto an object has been proposed as a method for quickly forming a complicated wiring pattern without using masking or the like. As a technique for directly printing wiring on the surface of such an object, for example, an inkjet wiring printing technique in which droplets of wiring ink are ejected onto the object and applied is known (Patent Document 1).

Japanese Patent Application Publication No. 2008-168216

However, the conventional inkjet method targets flat plates with relatively few irregularities, and when trying to form a wiring pattern on the surface of a workpiece that includes complex three-dimensional shapes such as rib structures and steps, uneven thickness and disconnections occur. There is a problem in that defects occur due to etc.

An object of the present invention is to provide a wiring printing head and a wiring printing apparatus that can form a wiring pattern on the surface of a workpiece including a complicated three-dimensional shape such as a rib structure.

One aspect of the disclosure below is a wiring printing head that forms a wiring pattern on the surface of a workpiece, which includes an insulating material discharge part that discharges a liquid insulating material to form an insulating layer, and a conductive material on the insulating layer. a wiring ink ejection unit that discharges wiring ink containing sexual particles to form a wiring ink layer; a drying mechanism that reduces volatile components of the wiring ink; and a firing mechanism that fires the wiring ink to form a wiring pattern. , in a wiring print head equipped with.

Another aspect resides in a wiring printing device that includes the wiring printing head of the above aspect and a joint portion that rotates the wiring printing head.

According to the wiring printing head and wiring printing apparatus of the above aspect, a wiring pattern can be formed on the surface of a workpiece including a complicated three-dimensional shape such as a rib structure or a step.

FIG. 2 is a perspective view showing an example of wiring formed inside an interior component of a vehicle. FIG. 1 is a plan view of a wiring print head according to an embodiment. 3 is a front view of the wiring print head of FIG. 2. FIG. 3 is a cross-sectional view showing a method of forming wiring using the wiring printing head of FIG. 2. FIG. 5A is a cross-sectional view of a wiring formed by the wiring printing head of FIG. 2, and FIG. 5B is a cross-sectional view of a wiring according to a comparative example. FIG. 7 is an explanatory diagram showing a problem caused by bumping caused by a wiring print head according to a comparative example. FIG. 3 is an explanatory diagram showing how wiring is formed on a rib structure by the wiring printing head of FIG. 2;

Hereinafter, preferred embodiments of a wiring printing head and a wiring printing apparatus will be described in detail with reference to the accompanying drawings.

In automobiles, automation of various operations including driving is progressing, and the values of users are changing from emphasizing operability centered on the driver to seeking a comfortable interior space. Along with these changes in user values, a simple and clean design is desired in the design of the vehicle interior space as well. However, current vehicles are equipped with various operation buttons for the shift lever, lamps, air conditioners, audio equipment, power windows, etc., and in order to ensure these functions, there are restrictions on the degree of freedom in design. It is occurring.

From the perspective of seeking a comfortable interior space, it is desirable to achieve both high quality and clean interior space without sacrificing the functionality achieved by conventional switches. In order to meet these needs, it has been considered to provide an interface function by providing a touch panel function or a display function to the surface of the interior parts 100, such as a door interior panel or a dashboard panel. It will be done.

When providing an interface function to the surface of the interior component 100 of the vehicle interior, as shown in FIG. It is required to arrange sensors 102 such as a pressure sensor, capacitance sensor, and temperature sensor, a light emitting element 104, an acoustic element 106, and the like.

The rear surface 101 side of the interior component 100 in FIG. 1 includes a rib structure 108 and a step 110 as a reinforcing structure. In order to form the sensors 102 and the like over a wide range of the back surface 101, it is required to form the wiring pattern 103 so as to go over these rib structures 108 and steps 110. However, since the rib structure 108 and the step 110 have a side surface 114 perpendicular to the main surface 112 of the interior component 100, it is difficult to form the wiring pattern 103 using a conventional inkjet wiring printing apparatus.

Below, a wiring printing head 12 and a wiring printing apparatus 10 that can form wiring on the surface of a complicated interior component 100 (workpiece) will be described.

As shown in FIG. 2, the wiring printing apparatus 10 of this embodiment includes a wiring printing head 12 that discharges wiring ink, a joint part 14 that rotates the wiring printing head 12, and a main body part 16 that supports the joint part 14. It is equipped with

As shown in FIG. 3, the wiring printing head 12 moves in the direction of the white arrow with respect to the interior component 100 by the main body portion 16 (see FIG. 2). The front surface 12a of the wiring print head 12 is a surface disposed to face the surface of the interior component 100, and the front surface 12a includes a position sensor 18, an insulating material discharge section 20, a wiring ink discharge section 22, and an air jet. A mouth 24 and a light irradiation section 26 are provided.

The position sensor 18 is arranged on the upstream side of the wiring print head 12 in the direction of movement. The position sensor 18 is composed of an optical sensor, a capacitance sensor, or an image sensor, and detects the distance between the interior component 100 and the wiring print head 12. The position sensor 18 is connected to the control device 30 of the main body 16 through sensor wiring 48 . The position sensor 18 transmits detection data to the control device 30 through the sensor wiring 48.

The insulating material discharge part 20 is provided on the downstream side of the position sensor 18 in the direction of movement. The insulating material discharge section 20 is configured with, for example, a thermal type or piezo type inkjet head. The insulating material discharge unit 20 pressurizes a liquid insulating material (insulating material ink) and discharges it as droplets toward the interior component 100 . The insulating material discharge unit 20 forms a linear insulating layer 52 with a predetermined width on the back side of the interior component 100. The insulating layer 52 prevents short circuit between the interior component 100 and the wiring. Furthermore, the adhesion between the wiring ink and the interior component 100 is improved to prevent disconnection of the wiring pattern 103 due to the wiring ink being repelled by the back surface 101 of the interior component 100.

As shown in FIG. 4, the wiring ink discharge section 22 is provided downstream of the insulating material discharge section 20 in the traveling direction. The wiring ink discharge unit 22 discharges wiring ink containing conductive particles onto the insulating layer 52 to form a layer made of wiring ink (wiring ink layer 54). The wiring ink discharge unit 22 is configured with, for example, a thermal type or piezo type inkjet head, and pressurizes the wiring ink and applies it on the insulating layer 52 as droplets. The applied wiring ink layer 54 is formed into a linear pattern extending along the direction in which the wiring printing head 12 moves. The wiring ink discharged from the wiring ink discharge section 22 contains, for example, metal particles such as silver and a solvent for fluidizing the metal particles.

The air injection port 24 (drying mechanism) is provided on the downstream side of the wiring ink ejection section 22 in the traveling direction. The air injection port 24 blows air onto the wiring ink layer 54 and the insulating layer 52 . At least a portion or all of the solvent contained in the wiring ink layer 54 and the insulating layer 52 is removed by the air injection port 24, and the wiring ink layer 54 and the insulating layer 52 are dried.

Note that the air injection port 24 may include a heating mechanism and may be configured to spray heated air onto the wiring ink layer 54 and the insulating layer 52. In this case, in order to prevent wire breakage due to bumping of the wiring ink layer 54 and the insulating layer 52, the air injection port 24 does not raise the temperature to a temperature higher than the boiling point of the solvent contained in the wiring ink layer 54 and the insulating layer 52. It is preferable to heat it to a certain degree.

Although an example in which the drying mechanism is constituted by the air injection port 24 has been shown here, the present embodiment is not limited to this. The drying mechanism may be a heating mechanism that evaporates the solvent by heating the wiring ink layer 54 and the insulating layer 52 in a temperature range in which bumping does not occur by irradiating light or applying an electromagnetic field. Further, an additional drying mechanism may be provided between the insulating material ejecting section 20 and the wiring ink ejecting section 22 to dry the insulating layer 52 separately.

The light irradiation unit 26 (baking mechanism) is disposed on the front side 12a of the wiring print head 12 at the rearmost side in the traveling direction. The light irradiation unit 26 includes an optical system that irradiates the area where the wiring ink layer 54 is formed with light having a narrowed irradiation area. The light irradiation unit 26 sinters the wiring ink layer 54 by irradiating the wiring ink layer 54 with, for example, laser light or light from a light source 38 (see FIG. 2) such as a xenon flash lamp. By this sintering, bonding progresses at the interface of metal particles (for example, silver particles), and a wiring layer 56 having high conductivity is formed. Further, during sintering, irradiation of the surrounding interior parts 100 is suppressed, so deterioration of the interior parts 100 can be prevented.

The intensity of the irradiation light from the light irradiation unit 26 (the heating temperature of the wiring ink layer 54) is adjusted as appropriate depending on the melting point and size of the metal particles. The lower the melting point of the metal and the smaller the particle size, the lower the temperature at which sintering can be performed. The light irradiation unit 26 is configured to irradiate the downstream side of the air injection position from the air injection port 24 to prevent defects caused by bumping of the solvent. Note that on the front surface 12a of the wiring printing head 12, the light irradiation section 26 may be provided on the side of the air injection port 24 or the like. Although an example in which the firing mechanism is configured with the light irradiation unit 26 has been described, the firing mechanism is not limited to the light irradiation unit 26, and may include various heating devices such as an induction heating device that selectively heats the wiring ink layer 54 by electromagnetic induction. May be used.

As shown in FIG. 2, the joint portion 14 is configured by connecting a plurality of joints 14a in a row. Adjacent joints 14a are connected via a rotation shaft 14b. A rotation mechanism for rotating the joint 14a around the rotation axis 14b is provided inside the joint 14a. When the joint 14a rotates, the joint portion 14 can rotate the wiring printing head 12 in the direction of the arrow and tilt the front surface 12a by 90° from the initial position shown. Thereby, the wiring printing device 10 can also make the front surface 12a face the side surface 114 (see FIG. 1) perpendicular to the main surface 112 of the interior component 100.

The main body portion 16 supports the proximal end of the joint portion 14 . The main body 16 includes a control device 30 , an insulating material tank 32 , a wiring ink tank 34 , an air compressor 36 , and a light source 38 . The insulating material tank 32 contains liquid insulating material. The main body portion 16 is driven by a drive mechanism (not shown) to move the wiring print head 12 in the advancing direction.

The insulating material tank 32 is connected to the insulating material discharge section 20 via an insulating material pipe 40 and supplies the insulating material to the insulating material discharging section 20 . The wiring ink tank 34 stores wiring ink. The wiring ink tank 34 is connected to the wiring ink discharge section 22 via a wiring ink pipe 42, and supplies wiring ink to the wiring ink discharge section 22.

The air compressor 36 is connected to the air injection port 24 via an air pipe 44 and supplies compressed air to the air injection port 24.

The light source 38 is made of, for example, a xenon flash lamp, and is connected to the light irradiation section 26 through an optical fiber 46. The light source 38 may be composed of a small element such as a laser diode, and in this case, the light source 38 may be built into the light irradiation section 26.

Control device 30 is connected to position sensor 18 through sensor wiring 48 . The control device 30 controls the position of the main body 16 based on the detected value of the position sensor 18 so as to keep the distance between the wiring print head 12 and the interior component 100 constant. Further, the control device 30 acquires the shape data of the interior component 100 and rotates the joint portion 14 according to the three-dimensional shape of the interior component 100 such as the rib structure 108 and the step 110, so that the front surface of the wiring printing head 12 is 12a is arranged so as to face the surface to which wiring ink is to be applied.

The wiring printing head 12 and the wiring printing apparatus 10 of this embodiment are configured as described above, and their functions will be described below along with a method for forming wiring on the interior component 100 (work).

As shown in FIG. 4, the wiring of this embodiment is formed by arranging the wiring printing head 12 in the wiring printing apparatus 10 so that its front surface 12a faces the coating target surface 100a of the interior component 100 in parallel. At this time, the control device 30 in FIG. 2 controls the position of the wiring print head 12 based on the detected value of the position sensor 18 so as to keep the front surface 12a a certain distance from the coating target surface 100a. Thereafter, the wiring printing device 10 moves the wiring printing head 12 relative to the interior component 100 in the direction of the outlined arrow. The wiring print head 12 may be moved by either a method of moving the main body portion 16 relative to the interior component 100 or a method of moving the interior component 100 side relative to the wiring print head 12.

The wiring printing head 12 forms an insulating layer 52 on the coating target surface 100a by discharging an insulating material from the insulating material discharging unit 20 at the front of the interior component 100 in the traveling direction. Next, wiring ink is ejected from the wiring ink ejection unit 22 of the wiring printing head 12 onto the insulating layer 52 to form a wiring ink layer 54. Thereafter, air is blown onto the wiring ink layer 54 and the insulating layer 52 from the air injection port 24 to dry the wiring ink layer 54 and the insulating layer 52.

As shown in FIG. 5B, when drying is not performed as in the wiring print head 12 of the comparative example, an insulating layer 52 and a wiring ink layer 54 are formed on a structure having an inclined surface like the rib structure 108A. When applied, the liquid insulating material and wiring ink flow vertically downward due to the action of gravity. As a result, a thin portion occurs in the insulating layer 52 and the wiring ink layer 54 on the rib structure 108A, and depending on the conditions, a disconnection portion 116 may occur as shown in the figure.

On the other hand, as shown in FIG. 5A, in the wiring print head 12 of this embodiment, the wiring ink layer 54 and the insulating layer 52 are dried immediately after being applied. By drying, at least a portion or all of the solvent contained in the wiring ink and the liquid insulating material is removed, and the fluidity of the wiring ink layer 54 and the insulating layer 52 is lost. Therefore, in this embodiment, the shape immediately after the wiring ink layer 54 and the insulating layer 52 are applied to the application target surface 100a is maintained. As shown in FIG. 5A, even when the wiring ink layer 54 and the insulating layer 52 are applied on an inclined surface where gravity acts, the wiring ink layer 54 is coated before the wiring ink and the liquid insulating layer 52 flow. Also, the insulating layer 52 can be fixed on the coating target surface 100a, and the wiring ink layer 54 and the insulating layer 52 can be formed with a uniform thickness.

Furthermore, as shown in FIG. 4, the light irradiation unit 26 of the wiring print head 12 sinteres the wiring ink layer 54 by irradiating the dried wiring ink layer 54 with light and heating it. The wiring ink layer 54 is removed by volatilization of residual organic components such as solvent, and the metal particles are bonded (sintered) to form a highly conductive wiring layer 56.

By the way, as shown in the comparative example in FIG. 6, if the applied wiring ink layer 54 is sintered without drying, the solvent contained in a large amount in the wiring ink layer 54 will be rapidly heated by the irradiation light. This may cause bumping. When bumping occurs, the wiring ink around the bump is blown away, creating a crater-shaped defect in which the wiring ink is removed. Depending on the width of the wiring pattern 103, a disconnection portion 116 may occur as shown in the figure.

On the other hand, in the wiring printing head 12 of this embodiment shown in FIG. 4, the solvent is removed by drying the wiring ink layer 54 in advance, so that bumping can be prevented and the occurrence of the disconnection part 116 can be prevented. . As described above, the wiring print head 12 forms the wiring pattern 103 including the insulating layer 52 and the wiring layer 56 while moving over the interior component 100.

As shown in FIG. 7, the wiring printing apparatus 10 can rotate the wiring printing head 12 according to the angle of the coating target surface 100a of the interior component 100. Thereby, the wiring pattern 103 made of the insulating layer 52 and the wiring layer 56 can be formed even on the side surface 114 or the like perpendicular to the main surface 112 of the interior component 100.

The wiring printing head 12 and wiring printing apparatus 10 of this embodiment have the following effects.

This embodiment relates to a wiring print head 12 that forms a wiring pattern 103 on the surface of an interior component 100 (work). The wiring print head 12 includes an insulating material discharging section 20 that discharges a liquid insulating material to form an insulating layer 52, and a wiring ink containing conductive particles on the insulating layer 52 to form a wiring ink layer 54. a drying mechanism (air injection port 24) that reduces the volatile components (solvent) of the wiring ink layer 54, and a baking mechanism (light irradiation) that bakes the wiring ink layer 54 to form the wiring pattern 103. Part 26).

According to the above configuration, since the wiring ink is dried and sintered immediately after being applied, even on the surface of the interior component 100 having a complicated three-dimensional shape, the wiring ink is dried and sintered before it flows due to gravity or surface tension. Since the wiring ink layer 54 can be hardened, the wiring pattern 103 with less variation in the thickness of the wiring layer 56 can be formed. Furthermore, since the solvent, which is a volatile component, is removed by drying before sintering, bumping in the sintering mechanism can be prevented, and the occurrence of wire breakage 116 due to bumping can be prevented.

In the wiring print head 12 from the above perspective, the drying mechanism may include an air jet port 24 that sprays air onto the wiring ink layer 54. According to this configuration, the solvent can be efficiently removed.

In the wiring print head 12 from the above perspective, the drying mechanism may be a heating mechanism that heats the wiring ink layer 54 at a temperature below the boiling point of the solvent. According to this configuration, the solvent can be efficiently removed while preventing bumping of the solvent.

In the wiring print head 12 described above, the firing mechanism may include a light irradiation unit 26 that narrows and irradiates light to a range having the same diameter as the width of the wiring pattern 103. According to this configuration, it is possible to prevent the area around the wiring pattern 103 from being heated, and it is possible to prevent the surface of the workpiece from becoming rough.

In the wiring print head 12 described above, the light irradiation section 26 may be configured to irradiate light from a xenon flash lamp.

The present embodiment relates to a wiring printing device 10 that includes a wiring printing head 12 that forms a wiring pattern 103 on the surface of an interior component 100 (work), and a joint portion 14 that rotates the wiring printing head 12. The wiring printing head 12 of the wiring printing apparatus 10 includes an insulating material discharging section 20 that discharges a liquid insulating material to form an insulating layer 52, and a wiring ink containing conductive particles on the insulating layer 52 to form a wiring. It includes a wiring ink discharge unit 22 that forms the ink layer 54, a drying mechanism that reduces volatile components of the wiring ink layer 54, and a firing mechanism that fires the wiring ink layer 54 to form the wiring pattern 103.

According to the wiring printing apparatus 10 from the above viewpoint, the wiring pattern 103 can be printed on the surface of the interior component 100 (workpiece) including a complex three-dimensional shape such as the rib structure 108 and the step 110 without causing defects such as uneven thickness or wire breakage. Can be formed.

In the wiring printing apparatus 10 from the above perspective, a control device 30 may be provided that rotates the joint portion 14 so that the wiring ink ejection portion 22 faces the surface of the interior component 100 (work). According to this configuration, the wiring pattern 103 can be formed even on the vertical side surface 114 and the like.

In the wiring printing apparatus 10 from the above perspective, a position sensor 18 may be provided at the leading end of the wiring printing head 12 in the direction of movement to detect the distance from the interior component 100 (work). According to this configuration, the distance between the wiring print head 12 and the interior component 100 can be kept constant, and variations in the thickness and width of the wiring layer 56 in the wiring pattern 103 can be suppressed.

Although the present invention has been described above with reference to preferred embodiments, it goes without saying that the present invention is not limited to the above embodiments, and that various modifications can be made without departing from the spirit of the present invention. stomach.

DESCRIPTION OF SYMBOLS 10... Wiring printing device 12... Wiring printing head 14... Joint part 14a... Joint 18... Position sensor 20... Insulating material discharge part 22... Wiring ink discharge part 24... Air injection port 26... Light irradiation part 30... Control device 52... Insulation Layer 54...Wiring ink layer 103...Wiring pattern

Claims (7)

A wiring printing head that forms a wiring pattern on the surface of a workpiece,
an insulating material discharge part that discharges a liquid insulating material to form an insulating layer;
a wiring ink discharge unit that discharges wiring ink containing conductive particles onto the insulating layer to form a wiring ink layer;
a drying mechanism that reduces volatile components of the wiring ink layer;
a firing mechanism that fires the wiring ink layer to form the wiring pattern;
a position sensor arranged at the tip in the traveling direction to detect the distance from the workpiece,
The wiring print head, wherein the position sensor, the insulating material discharge section, the wiring ink discharge section, the drying mechanism, and the baking mechanism are arranged in a line along the traveling direction. 2. The wiring printing head according to claim 1, wherein the drying mechanism includes an air jet port that sprays air onto the wiring ink layer. 2. The wiring printing head according to claim 1, wherein the drying mechanism includes a heating mechanism that heats the wiring ink layer at a temperature below the boiling point of the solvent of the wiring ink layer. 4. The wiring printing head according to claim 1, wherein the firing mechanism comprises a light irradiation unit that narrows and irradiates light to a range having the same diameter as the width of the wiring pattern. head. 5. The wiring print head according to claim 4, wherein the light irradiation section irradiates light from a xenon flash lamp. A wiring printing device comprising a wiring printing head that forms a wiring pattern on the surface of a workpiece, and a joint part that rotates the wiring printing head, the wiring printing head comprising:
an insulating material discharge part that discharges a liquid insulating material to form an insulating layer;
a wiring ink discharge unit that discharges wiring ink containing conductive particles onto the insulating layer to form a wiring ink layer;
a drying mechanism that reduces volatile components of the wiring ink layer;
a firing mechanism that fires the wiring ink layer to form the wiring pattern;
a position sensor arranged at the tip in the traveling direction to detect the distance from the workpiece,
The wiring printing device, wherein the position sensor, the insulating material discharge section, the wiring ink discharge section, the drying mechanism, and the baking mechanism are arranged in a line along the traveling direction. 7. The wiring printing apparatus according to claim 6, further comprising a control device that rotates the joint part so that the wiring ink discharge part faces the surface of the workpiece.

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