JP7502141B2 - Light emitting element module, explosion-proof lighting device, and method for manufacturing the light emitting element module - Google Patents

Description

The present invention relates to a light-emitting element module, an explosion-proof lighting device, and a method for manufacturing a light-emitting element module.

There are various standards that set out safety regulations for explosion-proof lighting equipment used in flammable gas atmospheres, including standards that stipulate electrical insulation between contacts of different poles. For example, the IEC 60079 series (JIS standards also have the same number) stipulates the minimum dimensions of clearance and creepage distance where contacts of different poles are close to each other. These regulations require that when the potential difference between contacts of different poles is 20V or less, the minimum dimensions of clearance and creepage distance be 1.6mm or more.

In addition, in explosion-proof lighting fixtures, if it is not possible to ensure clearances equal to or greater than the minimum dimensions of the clearance and creepage distances, electrical insulation must be ensured by covering the opposite pole contacts and between the opposite pole contacts with insulating material.

Techniques for such insulation are disclosed in, for example, US Pat. Nos. 5,993,333, 5,993,343, 5,993,352 and 5,993,624.
Patent Document 1 discloses a configuration in which the entire light source unit is placed in a tank and filled with translucent resin to provide insulation, Patent Document 2 discloses a configuration in which only the power supply terminal portion is potted with resin to provide insulation, and Patent Document 3 discloses a configuration in which an electrically insulating resin is made into a paste form and applied to the power supply terminal, and then semi-cured to provide insulation.

JP 2014-232641 A JP 2012-54025 A International Publication No. 2015/001667

2. Description of the Related Art Illumination fixtures that employ an SMD (Surface Mount Device) type LED package as a light source are widely known.
However, typically, the spacing between the power supply electrodes on the back surface of an LED package is narrower than 1.6 mm, which does not satisfy the above-mentioned minimum dimension, making it difficult to directly adopt the LED package as the light source for an explosion-proof lighting fixture.

It is possible to achieve insulation using the techniques described in Patent Documents 1 to 3 above, but each technique has the following problems:

In other words, since Patent Document 1 has a configuration in which the entire light source element, including the light irradiation surface, is fixed within a light-transmitting resin, the light from the light source element is emitted to the outside through a relatively thick resin layer, and even if the light-transmitting performance of the resin is improved, the irradiation efficiency of the light source unit is low.
In the case of Patent Document 2, since only the power supply terminal portion is potted, the irradiation surface of the light source element can be exposed in comparison with Patent Document 1, but it requires extra work such as providing a potting frame around the power supply terminal, and a relatively long curing time is required.
In order to eliminate the drawbacks described in Patent Document 2, Patent Document 3 is configured to apply a paste-like electrically insulating coating agent to the mounting board and terminals. However, in Patent Document 3, it is necessary to apply the paste-like coating agent having a thixotropic state three-dimensionally, and it is also necessary to keep the insulating coating film after coating in an incomplete state called a "semi-cured state", which is troublesome. In Patent Document 3, automatic application is difficult, and a complex device is required to realize automatic application.

The present invention aims to provide a light-emitting element module with insulation suitable for lighting fixtures, an explosion-proof lighting fixture, and a method for manufacturing a light-emitting element module.

One aspect of the present invention is a light-emitting element module in which a plurality of light-emitting element packages are arranged in a linear manner on a conductor portion of a mounting surface of an insulating substrate, the plurality of light-emitting element packages being surface-mounted, and the locations of the different-polarity contacts between the conductor portion and the light-emitting element packages on the mounting surface of the insulating substrate, which have a spacing of 1.6 mm or less , are covered with an insulating coating, and the insulating coating covers only the side surfaces of the light-emitting element packages .

One aspect of the present invention is characterized in that in the light-emitting element module, a plurality of the light-emitting element packages are arranged in a straight line.

One aspect of the present invention is characterized in that, in the light-emitting element module, the light-emitting element packages are rectangular in plan view, and the spacing between the light-emitting element packages is smaller than the width of the light-emitting element packages in a direction perpendicular to the arrangement direction of the light-emitting element packages.

One aspect of the present invention is characterized in that, in the light-emitting element module, the insulating coating has translucency, and the light-emitting element package is covered with the insulating coating together with the location of the opposite polarity contact.

One aspect of the present invention is an explosion-proof lighting device that includes any one of the light-emitting element modules described above.

One aspect of the present invention is a method for manufacturing a light-emitting element module in which a plurality of rectangular light-emitting element packages are arranged on a mounting surface of an insulating substrate so as to be electrically connected to each other in series and/or parallel to the conductor portion of the mounting surface of the insulating substrate, and is characterized in that an electrically insulating coating material with a viscosity of 0.5 to 30 (Pa·s) at an ambient temperature of 25°C is applied to two opposing sides of each of the light-emitting element packages.

One aspect of the present invention is a method for manufacturing a light-emitting element module in which multiple surface-mount type light-emitting element packages are linearly arranged on the mounting surface of an insulating substrate, the distance between the light-emitting element packages is smaller than the width of the light-emitting element packages in a direction perpendicular to the arrangement direction of the light-emitting element packages, and an electrically insulating coating material is continuously applied at a constant speed on both sides of the arrangement of the light-emitting element packages along the arrangement direction of the light-emitting element packages.

One aspect of the present invention is characterized in that in the manufacturing method of the light-emitting element module, the coating material has a viscosity of 0.5 to 30 (Pa·s) when the ambient temperature is 25°C.

The present invention provides a light-emitting element module with insulation suitable for use in lighting equipment, and an explosion-proof lighting equipment.

1 is a diagram showing a configuration of an LED module according to an embodiment of the present invention; FIG. 2 is a diagram illustrating a cross-sectional configuration of the LED module. FIG. 2 is a diagram showing a schematic diagram of a coating device. 4A to 4C are diagrams showing the application of a coating material in an insulating coating film forming step. 13 is a diagram showing a configuration of an LED module according to a modified example of the present invention. 11A to 11C are diagrams showing modified examples of the application of the coating material in the insulating coating film forming step.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing the configuration of an LED module 2 according to this embodiment.
The LED module 2 is a module that is contained within the body of an explosion-proof lighting fixture used in a flammable gas atmosphere and constitutes a light source that dissipates illumination light, and comprises an LED package 4 and a rectangular plate-shaped module substrate 5 on which the LED package 4 is mounted.
The number of LED modules 2 provided in one explosion-proof lighting fixture may be any number (one or more). Also, a light source for the explosion-proof lighting fixture may be configured by combining a plurality of LED modules 2 having different specifications.

FIG. 2 is a diagram illustrating a schematic cross-sectional configuration of the LED module 2. As shown in FIG.
The LED package 4 is an electronic component that is rectangular in plan view and is obtained by packaging an LED 3, which is an example of a light-emitting element, in a surface mount device (SMD) package. The LED package 4 has a package substrate 6, the LED 3 mounted in a sealed state on the package substrate 6, and a pair of power supply electrodes 7 consisting of a positive electrode and a negative electrode, and the power supply electrodes 7 are disposed on the bottom surface of the package substrate 6.

The module substrate 5 is an insulating substrate in which a conductor portion 8 such as copper foil constituting the wiring is provided on the surface of an electrically insulating substrate, and each of a pair of power supply electrodes 7 of the LED package 4 is soldered to this conductor portion 8, so that each soldering point forms a different polarity contact K.
In this embodiment, the LED packages 4 are linearly arranged at a predetermined interval Ta ( FIG. 1 ), and the conductor portion 8 is formed in a pattern shape that electrically connects in series these LED packages 4. In this embodiment, the predetermined interval Ta ( FIG. 1 ) is 2.25 mm, which is narrower than the width W (=3 mm) of the LED packages 4 in a direction perpendicular to the arrangement direction Da of the LED packages 4 (hereinafter referred to as the width direction Db).

The conductor portion 8 may have a pattern shape that connects the LED packages 4 in parallel, or may have a pattern shape that connects the LED packages 4 in series and in parallel.
The number of LED packages 4 provided in the LED module 2 and the overall length of the arrangement of the LED packages 4 are appropriately determined based on specifications such as the light distribution shape required for the LED module 2. In addition to the LED packages 4, other electronic components such as a metal connector 11 to which a power source or the like is connected and a capacitor 12 are also connected to the conductor portion 8 of the module substrate 5.

In the LED package 4 of this embodiment, the spatial distance La (FIG. 2) between a pair of power supply electrodes 7 constituting the opposite polarity contacts K is equal to or less than the minimum dimension (=1.6 mm) of the spatial distance and creepage distance stipulated in the IEC standard and the JIS standard. As shown in FIG. 1, the entire periphery of each LED package 4 on the mounting surface 5A of the module board 5 is covered with a transparent or non-transparent insulating coating film 20 having electrical insulation properties. By covering the entire periphery of the LED package 4 with the insulating coating film 20, as shown in FIG. 2, each opposite polarity contact K having a spatial distance La narrower than the minimum dimension is insulated by the insulating coating film 20, and the insulation required to fit the light source of the explosion-proof lighting fixture is obtained. The capacitor 12 may or may not be covered with the insulating coating film 20.

FIG. 3 is a diagram showing a schematic diagram of the coating device 30. As shown in FIG.
The painting device 30 comprises a work table 32 on which the module substrate 5 is set, and a discharge nozzle 34 which continuously discharges an electrically insulating coating material which is the material of the insulating coating film 20, and the discharge nozzle 34 is configured to be able to move relative to the module substrate 5 at a constant speed.

In the manufacturing process of the LED module 2 , when the insulating coating film 20 is applied to the module substrate 5 by using the coating device 30 , first, the module substrate 5 on which the LED package 4 is already mounted is set on a work table 32 .
Next, the painting device 30 positions the discharge nozzle 34 at a position that is at least a predetermined distance Tb (0.05 mm in this embodiment) above the mounting surface 5A of the module board 5, and moves the discharge nozzle 34 at a constant speed along each of the first path 50 and the second path 52 a predetermined number of times (once in this embodiment) while continuously discharging the coating material from the discharge nozzle 34.

As shown in FIG. 4, the first path 50 and the second path 52 are paths that are set to extend in the arrangement direction Da of the LED packages 4 on both sides of the arrangement of the LED packages 4. The first path 50 and the second path 52 are each set at a position spaced a predetermined distance Tc (1 mm in this embodiment) from the LED packages 4.

In this embodiment, the coating material is adjusted to a predetermined viscosity such that it flows on the mounting surface 5A of the module substrate 5 at the ambient temperature during the application process.

Therefore, when the coating material is continuously applied along the first path 50 and the second path 52 on the mounting surface 5A of the module substrate 5, the coating material flows appropriately. It penetrates into the gaps between the LED packages 4 in the arrangement direction Da. Since the predetermined distance Ta between the LED packages 4 is smaller than the width W of the LED packages 4 in the width direction Db, the coating material of the first path 50 and the second path 52 fills the gaps between the LED packages 4 without any gaps, and the entire circumference of each LED package 4 is reliably covered by the insulating coating film 20.

In this embodiment, the viscosity of the coating material is preferably 0.5 to 30 (Pa·s) at an ambient temperature of 25° C. Furthermore, from the viewpoint of productivity of the LED module 2, a preferable viscosity is 3 Pa·s±10%.
In other words, if the viscosity is higher than this preferred value, the coating material will not spread sufficiently around the entire circumference of the LED package 4, and if the viscosity is lower than the preferred value, the coating material will also flow out in the width direction Db perpendicular to the arrangement direction Da, causing the width of the insulating coating film 20 in the width direction Db to significantly exceed the design value, creating the risk of affecting other electronic components on the mounting surface 5A.

This embodiment provides the following advantages:

The LED module 2 of this embodiment is a unit in which a plurality of LED packages 4 are arranged so as to be electrically connected in series to a conductor section 8 on a mounting surface 5A of an insulating substrate, a module substrate 5. In the LED module 2, among the different polarity contacts K between the conductor section 8 on the mounting surface 5A of the module substrate 5 and the LED packages 4, the locations of the different polarity contacts K where the spatial distance is equal to or less than the minimum dimension of the creepage distance specified for explosion-proof lighting fixtures (1.6 mm in this embodiment) are covered with an insulating coating film 20.
As a result, with a simple structure of forming an insulating coating film 20, the insulation required to be compatible with the light source of an explosion-proof lighting fixture can be ensured, and an LED module 2 for an explosion-proof lighting fixture can be constructed using an LED package 4 in which the spatial distance La of the power supply electrode 7 is within the regulations for explosion-proof lighting fixtures.

In the LED module 2 of this embodiment, a plurality of LED packages 4 are arranged in a line.
As a result, the power supply electrodes 7 and conductor portions 8 of each LED package 4 are gathered in a linear area, and the process for applying and forming the insulating coating film 20 is simplified and manufacturing costs can be made relatively low compared to when the power supply electrodes 7 and conductor portions 8 are scattered on the mounting surface 5A.

In the LED module 2 of this embodiment, the LED packages 4 are rectangular in plan view, and the predetermined interval Ta between the LED packages 4 is smaller than the width W of the LED packages 4 in a width direction Db perpendicular to the arrangement direction Da of the LED packages 4.
As a result, by continuously applying the coating material along the first path 50 and the second path 52 extending in the arrangement direction Da of the LED packages 4 on both sides of the arrangement of the LED packages 4, the spaces between the LED packages 4 can be filled without gaps by the coating materials of the first path 50 and the second path 52, and an insulating coating film 20 can be formed around the entire circumference of each LED package 4.

In this embodiment, in the manufacturing process of the LED module 2 in which a plurality of LED packages 4 are arranged so as to be electrically connected in series to each other on the conductor portion 8 of the mounting surface 5A of the module substrate 5, an electrically insulating coating material with a viscosity of 0.5 to 30 (Pa·s) at an ambient temperature of 25°C is applied along the arrangement direction Da of the LED packages 4 on both sides sandwiching the arrangement of the LED packages 4.
By applying in this manner, the insulating coating film 20 can be reliably formed around the entire periphery of each LED package 4, and at the same time, excessive spreading of the insulating coating film 20 on the mounting surface 5A due to overflow can be prevented.

In this embodiment, in a manufacturing method for an LED module 2 in which a plurality of surface-mount type LED packages 4 are linearly arranged on the mounting surface 5A of a module substrate 5, a predetermined distance Ta between the LED packages 4 is smaller than a width W of the LED packages 4 in a width direction Db perpendicular to the arrangement direction Da of the LED packages 4, and an electrically insulating coating material is continuously applied at a constant speed along the arrangement direction Da of the LED packages 4 on both sides sandwiching the arrangement of the LED packages 4.
By applying the insulating coating 20 in this manner, it is possible to easily form the insulating coating 20 that covers the entire periphery of each of the LED packages 4 arranged in a straight line.

The above-described embodiment is merely an example of one aspect of the present invention, and any modification or application is possible without departing from the spirit of the present invention.

(Variation 1)
In the above-described embodiment, each LED package 4 as well as the entire periphery thereof (i.e., the entirety of each LED package 4) may be covered with a thin, light-transmitting insulating coating film 20. In this case, in the process of forming the insulating coating film 20, the insulating coating film 20 can be easily formed by moving the discharge nozzle 34 so as to cross directly above each LED package 4. Furthermore, since the insulating coating film 20 is thin, even if the insulating coating film 20 is applied to the irradiated surface of the LED package 4, the reduction in the amount of light irradiation can be sufficiently suppressed as long as the insulating coating film 20 has light transmissivity.

(Variation 2)
In the above-described embodiment, as shown in Fig. 5, the predetermined interval Ta between the LED packages 4 may be larger than the width W (Ta = 4.35 mm, W = 3 mm in the example of Fig. 5). In this case, in the process of forming the insulating coating film 20, it is preferable to form the insulating coating film 20 around the entire periphery of each LED package 4 by applying the coating material along the first path 50 and the second path 52 for each individual LED package 4 as shown in Fig. 6, rather than applying the coating material continuously around each LED package 4 along the first path 50 and the second path 52 as shown in Fig. 4 above.

(Variation 3)
In the above-described embodiment, the shape of the module substrate 5 of the LED module 2 is not limited to a long, substantially rectangular shape, but may be a polygon or a disk shape. The arrangement of the LED packages 4 is also not limited to a linear arrangement, but may be arranged in a circle or may be irregularly arranged. Even in these cases, the insulating coating film 20 can be formed around the entire periphery of each LED package 4 by applying a coating material to two opposing sides of each LED package 4.

(others)
The present invention is not limited to explosion-proof lighting fixtures and can be applied to any lighting fixture.
In addition, unless otherwise specified, the horizontal, vertical, and other directions, various numerical values, and shapes in the above-described embodiments include a range in which the same action and effect as those directions, numerical values, and shapes are achieved (a so-called equivalent range).

2. LED module (light emitting element module)
3. LED (light emitting element)
4. LED package (light emitting element package)
5. Module board (insulating board)
5A Mounting surface 7 Power supply electrode 8 Conductor portion 20 Insulating coating film 30 Coating device 34 Discharge nozzle 50 First path 52 Second path Da Array direction Db Width direction (direction perpendicular to the array direction)
K Different polarity contact La Spatial distance (spacing)
Ta: Predetermined interval W: Width

Claims (5)

A light emitting element module in which a plurality of light emitting element packages are linearly arranged on a conductor portion on a mounting surface of an insulating substrate,
The light emitting device packages are of a surface mount type,
Among the contacts of opposite polarities between the conductor portion and the light emitting element package on the mounting surface of the insulating substrate, the contacts of opposite polarities spaced apart by an interval of 1.6 mm or less are covered with an insulating coating film ;
The light-emitting element module, wherein the insulating coating film covers only the side surface of the light-emitting element package . The light emitting device package has a rectangular shape in a plan view,
The distance between the light emitting device packages is smaller than the width of the light emitting device packages in a direction perpendicular to the arrangement direction of the light emitting device packages.
The light-emitting element module according to claim 1 . An explosion-proof lighting fixture comprising the light-emitting element module according to claim 1 or 2 . A method for manufacturing a light emitting element module in which a plurality of surface mount type light emitting element packages are linearly arranged on a mounting surface of an insulating substrate, comprising:
A distance between the light emitting device packages is smaller than a width of the light emitting device packages in a direction perpendicular to an arrangement direction of the light emitting device packages,
Applying an electrically insulating coating material continuously at a constant speed on both sides of the array of the light emitting device packages along the array direction of the light emitting device packages;
A method for manufacturing a light-emitting element module. 5. The method for manufacturing a light-emitting element module according to claim 4 , wherein the coating material has a viscosity of 0.5 to 30 (Pa·s) at an atmospheric temperature of 25°C.

Images