JP2018198239A - Light-emitting module, method for manufacturing the same, and lid member for light-emitting module - Google Patents

Abstract

To provide a light-emitting module capable of maintaining a sealed state of a light-emitting element for a long period, and a method for manufacturing the light-emitting module.SOLUTION: The light-emitting module 1 includes: a package substrate 2 which has an arrangement surface 2a where a light-emitting element 3 is arranged and side walls 2b standing from the arrangement surface 2a in such a way that a space S is provided outside the light-emitting element 3, encircling the element; a lid member 4 which has a translucent top plate 4a which is arranged in such a way that it covers an inner space S of the side walls 2b from above and side walls 4b which stands on an outer peripheral part of a top plate 4a and is arranged outside the side walls 2b of the package substrate 2; and a sealing part 5 bonding the package substrate 2 and the lid member 4, which is outside the side walls 2b of the package substrate 2 and provided at a position where no light-emitting element 3 can be seen.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light emitting module in which a light emitting element is sealed, a manufacturing method thereof, and a light emitting module lid member.

LED elements (Light Emitting Diodes) are used as light sources in a wide range of fields such as illumination, signals, and optical communication. This LED element (light emitting element) is composed of a compound semiconductor. Therefore, in order to protect the light-emitting element from the external environment, the light-emitting element is sealed (sealed) with a light-transmitting material and packaged to obtain a light-emitting module.
As a sealing method of the light emitting module, for example, as shown in Patent Document 1, a light emitting element attached to a lead electrode is covered with a resin material, or as shown in Patent Documents 2 and 3, an opening is provided. There is a method in which a light emitting element is accommodated in a package substrate, and the opening is covered with a window member such as a glass plate.

Furthermore, recently, light emitting elements that emit deep ultraviolet light have been developed and are already on the market.
The main use of the light emitting element that emits deep ultraviolet light is used for the purpose of sterilization as shown in Patent Documents 4 and 5, for example. For this reason, for example, a light-emitting module suitable for use in sterilizing a light-emitting element in water such as drinking water is expected.

JP, 2006-186974, A JP 2017-59716 A JP 2004-253638 A JP 2013-173564 A JP 2017-29936 A

As described above, in order to use the light-emitting element for light emission and sterilization in water, the light-emitting module must be sealed (sealed) with a light-transmitting material.
However, in the sealing method in which the light emitting element attached to the lead electrode as shown in Patent Document 1 is covered with a resin material, there is a problem that the resin is severely deteriorated by deep ultraviolet light and sealing is likely to be incomplete. there were. Furthermore, since the resin material absorbs ultraviolet light, there is a problem that it is not preferable from the viewpoint of efficiency.

On the other hand, as shown in Patent Documents 2 and 3, in a sealing method in which a light emitting element is accommodated in a package substrate provided with an opening, and the opening is covered with a window member such as a glass plate, the window member is made of glass. Since it consists of a plate, absorption of ultraviolet light is suppressed, and the aspect of efficiency is preferable.
However, there has been a problem that the joint between the package body and the window member is deteriorated by deep ultraviolet light, and sealing is likely to be incomplete.

More specifically, ceramic members such as LTCC (Low Temperature Co-fired Ceramics) and AlN (aluminum nitride) are used for package substrates that are generally used. The thermal expansion coefficient of LTCC or AlN is 4 to 8 × 10 ⁻⁶ / K, while the thermal expansion coefficient of quartz glass that can sufficiently transmit ultraviolet light is 5 to 6 × 10 ⁻⁷ / K. The thermal expansion difference is very large.
Therefore, it is difficult to reduce these differences in thermal expansion by using a low-melting glass which is a general sealing material, and sealing with a solder containing a resin such as silicone or a flux is performed.
However, when sealing is performed with a resin material such as silicone or solder containing a flux, there is a problem that the resin material is greatly deteriorated by deep ultraviolet light and sealing is likely to be incomplete.

  Based on the premise of a sealing method in which a light-emitting element is accommodated in a package substrate having an opening as shown in Patent Documents 2 and 3, and a window member such as a glass plate covers the opening. The present invention has been completed by studying a light emitting module that suppresses deterioration of the sealing material due to ultraviolet light, improves the durability of the sealed state, and further suppresses a decrease in the efficiency of irradiation with ultraviolet light.

  The present invention has been made under the above circumstances, and the present invention provides a light emitting module capable of maintaining a sealed state of a light emitting element for a long time, a method for manufacturing the light emitting module, and a lid member for the light emitting module. With the goal.

The light emitting module according to the present invention made to achieve the above object includes an arrangement surface on which the light emitting element is arranged, and a side wall erected from the arrangement surface so as to surround and surround the light emitting element. A package substrate, a translucent top plate arranged so as to cover the space inside the side wall from above, and a side wall standing on the outer periphery of the top plate and arranged outside the side wall of the package substrate. And a sealing member that is provided on a position outside the side wall of the package substrate and that cannot face the light emitting element, and that joins the package substrate and the lid member. .
Since the light emitting module according to the present invention has the above-described configuration, the light from the light emitting element does not directly hit the sealing portion, so that deterioration of the sealing material forming the sealing portion is suppressed, and the light emitting element is arranged. The sealed space can be reliably maintained for a long period of time.

  Here, it is desirable that the sealing portion is disposed between the lower end surface of the side wall of the lid member and the arrangement surface of the package substrate. The sealing portion may be disposed between the side wall of the lid member and the side wall of the package substrate.

The lid member is preferably sintered silica.
When the lid member is formed of sintered silica, light absorption from the light emitting element is small, and a decrease in irradiation efficiency can be suppressed. In particular, when the lid member has a complicated shape, the lid member can be easily obtained by molding and sintering the above-mentioned shape in a molding die by a cast method or a sol-gel method.

  In addition, when a metal layer is provided on the side wall end of the lid member, the metal layer can reflect light transmitted through the inside of the lid member, thereby deteriorating the sealing material forming the sealing portion. Can be suppressed.

  Further, bubbles may be included in the side wall of the lid member, and a metal oxide may be included in the side wall of the lid member. As described above, when bubbles or metal oxides are included in the side wall of the lid member, the light transmitted through the lid member can be reflected or absorbed, and the sealing material that forms the sealing portion is deteriorated. Can be suppressed.

  Moreover, you may equip a part of side wall of a cover member with the inclined surface part which made the thickness of the side wall gradually thin. By this inclined surface portion, light transmitted through the inside of the lid member can be reflected, and deterioration of the sealing material forming the sealing portion can be suppressed.

The light emitting element may be a light emitting element that emits deep ultraviolet light.
As the light-emitting element, a light-emitting element that emits visible light or infrared light can be used. In particular, in the case of a light-emitting element that emits ultraviolet light that is greatly affected by deterioration of the sealing material forming the sealing portion, the present invention. The effect of can be obtained more and is preferable.

The sealing part for joining the package substrate and the lid member may be a resin material.
A metal material or a glass material can be used as a sealing material for forming the sealing portion, but a resin material can be used because light from the light emitting element is not directly applied.
When a resin material is used for the sealing portion, the difference in thermal expansion between the package substrate and the lid member can be reduced, and the sealing operation can be easily performed, which is preferable.

A method for manufacturing a light emitting module according to the present invention, which has been made to achieve the above object, includes a step of disposing a light emitting element in a space provided by an arrangement surface of a package substrate and a side wall standing from the arrangement surface, In the step of arranging the side wall of the lid member made of the top plate and the side wall to be outside the side wall of the package substrate so as to confine the space in which the light emitting element is arranged, and at a position where the light emitting element cannot be faced, Joining the package substrate and the lid member and sealing the package substrate and the lid member.
In the method for manufacturing a light emitting module according to the present invention, in order to seal the space in which the light emitting element is disposed, the side wall of the lid member is disposed outside the side wall of the package substrate, and the light emitting element is faced. The package substrate and the lid member are joined and sealed at a position where the contact cannot be made.
Therefore, in the light emitting module manufactured by this manufacturing method, since light from the light emitting element does not directly hit the sealing portion, deterioration of the sealing material forming the sealing portion is suppressed, and the light emitting element is It is possible to reliably maintain the sealed space for a long period of time.
Moreover, the formation state of the sealing part can be confirmed from the outside, and the space in which the light emitting element is arranged can be reliably sealed.

  The lid member according to the present invention is preferably a translucent lid member obtained as a sintered body by forming and sintering after preparing granulated powder containing silica particles. If the lid member is formed by a casting method or a sol-gel method, even a lid member having a complicated shape can be easily manufactured.

Further, the light emitting module cover according to the present invention is made of sintered silica, and includes a top plate and a side wall erected from the outer periphery of the top plate, at least the top plate has translucency, A lens is formed on a flat plate or a top plate.
When the light emitting module cover is made of sintered silica, it is excellent in ultraviolet light transmissivity and is not difficult to manufacture even if it has a fine and complicated shape.

Furthermore, it is preferable to provide light absorption or reflection means on the side wall of the lid member.
The ultraviolet light that has entered the inside of the lid member is repeatedly reflected, and some reaches the sealing part. For this reason, an inclined part is provided on the side wall of the lid member, or a notch part is provided to arrange a surface that reflects light, a fine foam is confined on the side wall of the lid member to reflect light, or metal oxidation is performed. Deterioration of the sealing material can be prevented by doping a material to absorb light or providing a metal coating layer to block light.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the light emitting module which improved the sealing durability of the light emitting element, the light emitting module, and the cover member for light emitting modules can be obtained.

FIG. 1 is a cross-sectional view showing an embodiment of a light emitting module according to the present invention. 2 is a cross-sectional view taken along the line II of FIG. FIG. 3 is a view showing a first modification of the embodiment shown in FIG. 1, and is a cross-sectional view corresponding to FIG. FIG. 4 is a cross-sectional view showing a second modification of the embodiment shown in FIG. FIG. 5 is a cross-sectional view showing a third modification of the embodiment shown in FIG. FIG. 6 is a cross-sectional view showing a fourth modification of the embodiment shown in FIG. FIG. 7A is a cross-sectional view showing a fifth modification of the embodiment shown in FIG. 1, and FIG. 7B is an enlarged view of the main part of FIG.

An embodiment of a light emitting module according to the present invention will be described with reference to FIG.
As shown in FIG. 1, the light emitting module 1 includes a package substrate 2, a light emitting element 3, a lid member 4, and a sealing portion 5.

A light emitting element 3 is arranged on the arrangement surface 2 a of the package substrate 2.
A side wall 2b protruding from the arrangement surface 2a of the package substrate 2 is formed so as to surround the outside of the region X in which the light emitting element 3 is arranged. The side wall 2b is a cylindrical side wall erected from the surface of the package substrate 2, and is provided so as to surround the outside of the light emitting element 3 while maintaining a space.
That is, the light emitting element 3 is disposed so as to be accommodated in the space S formed by the side wall 2b.

The package substrate 2 is a ceramic substrate containing alumina (Al ₂ O ₃ ), aluminum nitride (AlN), or the like. HTCC, High Temperature Co-fired Ceramic).
An external electrode (not shown) connected to the anode or cathode of the light emitting element 3 is provided on the back surface 2c of the package substrate 2.

The light-emitting element 3 is an LED composed of a compound semiconductor, and is housed in the space S. The light of the light-emitting element 3 can be emitted outside through the top plate 4a of the lid member 4. ing.
The light from the light-emitting element 3 is emitted to the area Y shown in FIG. 1, and the area shaded by the side wall 2b (shown by hatching in FIG. 1) is not directly irradiated with the light from the light-emitting element 3.

A light emitting element that emits deep ultraviolet light is used as the light emitting element 3. For example, a light-emitting element using aluminum gallium nitride (AlGaN) can be used.
This deep ultraviolet light refers to an ultraviolet region having a wavelength of 200 nm to 350 nm. By using such a light emitting element that emits deep ultraviolet light, for example, sterilization of drinking water or the like can be performed.

The lid member 4 seals the space S inside the side wall 2b and is a translucent member that covers the upper opening 2b1 of the side wall 2b.
The lid member 4 includes a top plate 4a facing the upper opening 2b1 of the side wall 2b, and a side wall 4b erected on one surface of the top plate 4a. The side wall 4 b is formed in a cylindrical shape and is disposed outside the side wall 2 b of the package substrate 2.

  1 shows the case where the top plate 4a of the lid member 4 is formed in a flat plate shape (flat surface), the cross-sectional shape of the top plate 4a is a cross-sectional shape of a lens such as a concave lens, a convex lens, or a fly-eye lens. The lens may be integrally formed on the top plate.

In the case where the lid member 4 is formed of silica glass, light absorption from the light emitting element is small and a decrease in irradiation efficiency can be suppressed.
In particular, when the lid member 4 is formed of sintered silica, even if the lid member 4 has a complicated shape, the lid member 4 having a predetermined shape can be easily obtained by molding and sintering. .

The sealing portion 5 is a portion where the package substrate 2 and the lid member 4 are joined, and is provided outside the side wall 2b and at a position where the light emitting element 3 cannot be faced. That is, the sealing part 5 is disposed in a region (shown by hatching in FIG. 1) that is shaded by the side wall 2b.
Thus, since the sealing part 5 is arrange | positioned in a specific position, the light from the light emitting element 3 does not hit directly. As a result, deterioration of the sealing material forming the sealing portion 5 can be suppressed, and the space S surrounded by the side wall 2b in which the light emitting element 3 is disposed can be surely sealed for a long period of time.

As a sealing material for the sealing portion 5, in addition to a metal material and a glass material, the sealing portion 5 is not directly exposed to light from the light emitting element, and therefore can be sealed using a resin material.
As the metal material, gold tin, electrical solder, Kovar, etc. can be used, and as the glass material, low melting point such as bismuth glass, tin-phosphate glass, or vanadium glass substantially free of lead. Glass can be used.
As the resin material, silicone resin, phenol resin, polyimide resin, epoxy resin, adhesive, or the like can be used. In particular, the use of a resin material is preferable because the package substrate 2 and the lid member 4 can be easily joined.
At the time of sealing, the space S is filled with an inert gas such as nitrogen.

Thus, the light emitting module 1 seals the light emitting element 3 that emits ultraviolet light, and emits the ultraviolet light to the outside via the lid member 4. When silica glass (sintered silica) is used as the lid member 4, deep ultraviolet light can be efficiently emitted to the outside without absorbing deep ultraviolet light.
In addition, since the sealing portion 5 is provided outside the side wall 2b and at a position where the light emitting element 3 cannot be faced, the deep ultraviolet light from the light emitting element 3 is not directly applied. Therefore, sealing can be performed using a resin material, and the difference in thermal expansion between the package substrate 2 and the lid member 4 can be reduced.
As a result, deterioration of the sealing material forming the sealing portion 5 can be suppressed, and the space S in which the light emitting element 3 is disposed can be reliably sealed over a long period of time.

Next, a method for manufacturing the light emitting module 1 will be described.
First, the lid member 4 is manufactured. The lid member 4 can be produced by a known method for producing sintered silica. That is, after preparing a granulated powder containing silica particles, a slurry is produced from the obtained granulated powder, and the slurry is put into a mold or the like, molded, dried, and then sintered. A lid member is obtained.

Next, the package substrate 2 is manufactured.
The package substrate 2 is manufactured by using a known package substrate manufacturing method.
In addition, the side wall 2b is formed in the specific position (specific height dimension) which cannot face the light emitting element 3 from the sealing part 5. FIG.

And the light emitting element 3 is accommodated in the space S formed by the side wall 2b of the package substrate 2, and the package substrate 2 and the light emitting element 3 are electrically connected.
Next, the lid member 4 is mounted so that the side wall 4b of the lid member 4 is positioned outside the side wall 2b of the package substrate 2, the package substrate 2 and the lid member 4 are joined, and the light emitting element 3 is disposed. The space S is confined. When bonding, the package substrate 2 and the lid member 4 are bonded in a state where the space S is filled with an inert gas such as nitrogen (N ₂ ).

In the method of manufacturing the light emitting module according to the present invention, the side wall 4b of the lid member 4 is disposed outside the side wall 2b in order to seal the space S in which the light emitting element 3 is disposed, and the light emitting element 3 is faced. The package substrate 2 and the lid member 4 are sealed by the sealing portion 5 at a position where it cannot be used.
Therefore, the formation state of the sealing part 5 can be easily confirmed from the outside, and the space S in which the light emitting element 3 is arranged can be reliably sealed.

  Moreover, since the said cover member 4 can be manufactured by preparing the granulated powder containing a silica particle, and shape | molding and sintering, even if it is the cover member 4 of complicated shape, a cover member is easy. 4 can be produced.

Next, a modification of the embodiment of the light emitting module according to the present invention will be described with reference to FIGS.
(First modification)
In the above embodiment, as shown in FIG. 2, the side wall 2b and the side wall 4b are formed in a cylindrical shape. However, as shown in FIG. 3, the side wall 2b and the side wall 4b may be formed in a rectangular shape. good.

(Second modification)
In the above embodiment, as shown in FIG. 1, the inner side surface of the side wall 2b is formed substantially perpendicular to the package substrate 2, but as shown in FIG. 4, the inner side surface of the side wall 2b. 2b2 may be formed with a curved surface. Of course, you may make it a slope without making it curve.

(Third Modification)
Next, a third modification will be described based on FIG.
The third modification is characterized in that a metal layer 6 is provided at the end of the side wall 4b of the lid member 4. This metal layer 6 is a so-called reflecting member, and reflects light transmitted through the inside of the lid member 4 (a state of reflection is schematically indicated by an arrow in the figure).
Thereby, it can suppress that a deep ultraviolet light hits the sealing part 5, or can prevent it, and can suppress degradation of the sealing part 5 (sealing material).
This metal layer is formed by forming an aluminum thin film by sputtering.

(Fourth modification)
Next, a fourth modification will be described based on FIG.
The fourth modification is characterized in that a part of the side wall 4b of the lid member 4 is provided with an inclined surface portion 4b1 in which the thickness of the side wall 4b is gradually reduced.
The deep ultraviolet light irradiated on the top plate 4a of the lid member 4 passes through the top plate 4a and is emitted to the outside. However, a part of the deep ultraviolet light does not pass through the top plate 4 a, travels through the inside of the lid member 4 while repeating reflection, and reaches the sealing portion 5. As a result, the sealing material of the sealing portion is deteriorated.
Like this 4th modification, the light which propagates the inside of the cover member 4 can be reflected by this inclined surface part 4b1 (in the figure, the reflective state is shown with an arrow), and the sealing part 5 is made Deterioration of the sealing material to be formed can be suppressed. In addition, the position and angle of the inclined surface are preferably provided at a position and an angle at which the light that repeats reflection in the side wall is received most vertically when the dimensions and shape of the package substrate, lid member, and light emitting element are determined.
Further, the inclined surface portion may be provided not only on the inner side of the side wall 4 b of the lid member 4 but also on the outer side. Further, a plurality of V-shaped cuts may be provided so as to go around the side wall 4b of the lid member.
Furthermore, by providing a protrusion on the outer periphery of the side wall 2b of the package substrate 2 as shown in FIG. 6, it is possible to prevent light from being directly transmitted from the inclined surface portion 4b1 to the sealing portion 5.
As shown in FIG. 6, the sealing portion 5 may be disposed between the side wall 4 b of the lid member 4 and the side wall 2 b of the package substrate 2.

(Fifth modification)
Next, a fifth modification will be described based on FIG.
This fifth modification is characterized in that bubbles (fine bubbles) 7 are included in the side wall 4b of the lid member 4. In this way, when fine bubbles 7 are included in the side wall 4b of the lid member 4, as shown in FIG. 7B, light transmitted through the inside of the lid member 4 (illustrated by arrows in the figure). ) Is reflected on the inner peripheral surface of the bubble 7, so that deterioration of the sealing material forming the sealing portion 5 can be suppressed.
The diameter of the fine bubbles is preferably several hundred μm to several mm where geometric scattering is dominant. It is preferable that the density of the bubbles is large so as not to affect the strength.

(Sixth Modification)
Next, a sixth modification will be described.
The sixth modification is characterized in that the side wall 4b of the lid member 4 contains a metal oxide. Thus, when the side wall 4b of the lid member 4 contains a metal oxide, the light transmitted through the inside of the lid member is absorbed by the metal oxide, and a sealing material that forms a sealing portion is formed. Deterioration can be suppressed.
The metal oxide may be titanium oxide, cerium oxide, zinc oxide, or the like, and may be formed by sputtering on the side wall 4b or may be doped from the end of the side wall 4b before sintering.

In the above embodiment and the first to sixth modifications, the case where a light emitting element emitting ultraviolet light is used, but a light emitting element emitting visible light or infrared light may be used.
A plurality of first to sixth modifications may be performed simultaneously.
Furthermore, the side wall of the package substrate 2 is not single as described above, but may be double, and the side wall of the lid member may be fitted between the two side walls.

DESCRIPTION OF SYMBOLS 1 Light emitting module 2 Package board 2a Arrangement surface 2b Side wall 2b1 Upper opening 2b2 Inner side surface 2c Back surface 3 Light emitting element 4 Lid member 4a Top plate 4b Side wall 5 Sealing part 6 Metal layer 7 Bubble

Claims (14)

A package substrate having an arrangement surface on which the light emitting element is arranged, and a side wall erected from the arrangement surface so as to surround and surround the light emitting element;
A lid member having a translucent top plate arranged so as to cover the space inside the side wall from above, and a side wall standing on the outer periphery of the top plate and arranged outside the side wall of the package substrate;
A sealing portion that is provided on a position outside the side wall of the package substrate and that cannot face the light emitting element, and that joins the package substrate and the lid member;
A light emitting module comprising:   The light emitting module according to claim 1, wherein the sealing portion is disposed between a lower end surface of a side wall of the lid member and an arrangement surface of the package substrate.   The light emitting module according to claim 1, wherein the sealing portion is disposed between a side wall of the lid member and a side wall of the package substrate.   The light emitting module according to any one of claims 1 to 3, wherein the lid member is sintered silica.   The light emitting module according to any one of claims 1 to 4, wherein a metal layer is provided at a lower end portion of the side wall of the lid member, and the light transmitted through the inside of the lid member is reflected by the metal layer.   The light emitting module according to claim 1, wherein bubbles are included in a side wall of the lid member.   The light emitting module according to claim 1, wherein a metal oxide is included in a side wall of the lid member. A part of the side wall of the lid member is provided with an inclined surface portion in which the thickness of the side wall is gradually reduced,
The light emitting module according to claim 1, wherein light transmitted through the inside of the lid member is reflected by the inclined surface portion.   The light emitting module according to claim 1, wherein the light emitting element is a light emitting element that emits deep ultraviolet light.   The light emitting module according to any one of claims 1 to 9, wherein a sealing portion that joins the package substrate and the lid member is formed of a resin material. A method for manufacturing a light emitting module according to any one of claims 1 to 10,
A step of arranging a light emitting element in a space provided by a side surface standing from the arrangement surface of the package substrate and the arrangement surface;
A step of arranging the side wall of the lid member including the top plate and the side wall to be outside the side wall of the package substrate so as to confine the space in which the light emitting element is arranged;
Bonding the package substrate and the lid member at a position where the light emitting element cannot be faced, and sealing,
The manufacturing method of the optical module characterized by including.   The method for manufacturing a light emitting module according to claim 11, wherein the lid member is a lid member obtained by preparing granulated powder containing silica particles and then molding and sintering the granulated powder.   It is made of sintered silica and consists of a top plate and side walls erected from the outer periphery of the top plate. At least the top plate has translucency and the top plate is a flat plate or a lens is formed on the top plate. A lid member for a light emitting module characterized by the above.   The light emitting module lid member according to claim 13, wherein light absorbing or reflecting means is provided on a side wall of the lid member.

Images