Patent Description:
A light-emitting device is known that includes a package having a base body, a frame body, and lead terminals which penetrate a side surface of the frame body, and in which a light-emitting element and the like are mounted on the package (refer to <CIT>, <CIT>, <CIT> or <CIT>).

In the case where a large number of light-emitting elements are arranged on such a package, due to heat generated by the light-emitting elements and the like, thermal stress may be applied to each member. Accordingly, detachment easily occurs at portions with relatively low bonding strength. For example, when a lead terminal is bonded to a through-hole of a frame body, which is portion with a relatively small area, the bonding strength at a periphery of the lead terminal is low and a gap is likely to be generated. The generation of such gaps may cause a decline in airtightness of the light-emitting device.

Certain embodiments of the present invention are described below.

In one embodiment, a light-emitting device is as defined in claim <NUM>.

In another embodiment, a package for a light-emitting device is as defined in claim <NUM>.

With the configurations as defined in claims <NUM> and <NUM>, respectively, a relatively inexpensive light-emitting device and a package for the light-emitting device can be provided in which airtightness is not easily decreased.

<FIG> is a schematic plan view of a light-emitting device <NUM> according to one embodiment. <FIG> is a sectional view taken along a line A-A in <FIG>, <FIG> is a sectional view taken along a line B-B in <FIG>, and <FIG> is a partial enlarged view showing an enlargement of a portion of <FIG>. In addition, <FIG> is a schematic plan view of a package <NUM> used in the light-emitting device <NUM>. <FIG> is a sectional view taken along a line C-C in <FIG> and <FIG> is a partial enlarged view showing an enlargement of a portion of <FIG>. <FIG> is a schematic sectional view taken along a line D-D in <FIG>. Furthermore, <FIG> is a schematic exploded perspective view of the package <NUM>.

As shown in <FIG>, the light-emitting device <NUM> includes a base body <NUM>, light-emitting elements <NUM>, a frame body <NUM>, lead terminals <NUM>, and a cover <NUM>. The base body <NUM> includes an upper surface 12A and a lower surface 12B. The light-emitting element <NUM> is mounted on the upper surface 12A of the base body <NUM>. The frame body <NUM> is bonded to an upper surface 12A side of the base body <NUM> so as to surround the light-emitting elements <NUM>. The frame body <NUM> includes first through-holes 14c that penetrate the frame body <NUM> so as to connect an inside and an outside of the frame body <NUM>. The lead terminals <NUM> are each inserted into each of the first through-holes 14c and are electrically connected to the light-emitting elements <NUM>. The cover <NUM> is bonded to the frame body <NUM> so as to seal the light-emitting elements <NUM>. The light-emitting device <NUM> further includes plate bodies <NUM> and fixing members <NUM>. The plate bodies <NUM> are bonded to outer lateral surfaces 14A of the frame body <NUM>. Each of the plate bodies <NUM> includes second through-holes 16a which penetrate each of the plate bodies <NUM> in a direction same as a penetrating direction of the first through-holes 14c. Each of the lead terminals <NUM> is inserted into each of the second through-holes 16a, and the plate bodies <NUM> each has a thickness larger than a thickness of the frame body <NUM>. The fixing members <NUM> are each disposed inside each of the second through-holes 16a and fix the lead terminals <NUM>.

With the configuration described above, a relatively inexpensive light-emitting device <NUM> can be obtained in which airtightness is not easily decreased. A detailed description of this feature will be given below.

In the light-emitting device <NUM>, energization is required for light emission of the light-emitting element. Such energization causes the light-emitting element <NUM> to generate heat, and the heat generated by the light-emitting element <NUM> is transmitted over the entire light-emitting device <NUM>. In addition, at the time of bonding the light-emitting element <NUM> and the like using a bonding material, the entirety of the light-emitting device <NUM> may be heated in order to, for example, cure the bonding material. Because the light-emitting device <NUM> is constituted by various members with different thermal expansion coefficients, thermal stress is generated on each member when a temperature is changed. Due to thermal stress generated on each member, separation between each member may be occurred, and airtightness may be decreased.

For this reason, in the light-emitting device <NUM>, the frame bodies <NUM> bonded to the base body <NUM> each have a thickness smaller than that of the plate body <NUM>. With this arrangement, the thermal stress generated on the frame body <NUM> can be reduced due to deformation of the frame body <NUM>. Furthermore, each of the lead terminals <NUM> is fixed by a fixing member in each of the second through-holes 16a defined in the plate body <NUM>, which has a thickness greater than that of the frame body <NUM>. In view of fixing of the lead terminals <NUM>, each of the lead terminals may be fixed in respective one of the first through-holes 14c of the frame body <NUM>. However, a thickness of the frame body <NUM> is reduced to facilitate deformation of the frame body <NUM>, and accordingly, an area of an inner wall of each of the first through-holes 14c is also reduced. For this reason, it is difficult to hold the lead terminals <NUM> with the first through-holes 14c of the frame body <NUM> in an airtight manner. On the other hand, each of the plate bodies <NUM> has a thickness greater than that of the frame body <NUM>, so that an area of an inner wall of the second through-hole 16a is larger than the area of the inner wall of the first through-hole 14c. Therefore, fixing each of the lead terminals <NUM> in each of the second through-holes 16a defined in the plate body <NUM> allows the lead terminals <NUM> to be fixed more firmly. For this reason, a decrease in airtightness of the light-emitting device <NUM> can be prevented. Since the plate bodies <NUM> are bonded to lateral surfaces of the frame body <NUM>, the plate bodies <NUM> and the frame body <NUM> are bonded to each other via relatively large areas. Accordingly, the plate bodies <NUM> and the frame body <NUM> are not easily separated from each other and, even if a partial separation is occurred, the partial separation does not easily create a gap connecting an inside and an outside of a sealed space.

It may be assumed that airtightness can be secured without using the plate bodies by increasing a thickness of the frame body itself. However, increasing the thickness of the frame body itself may lead to not only increase in a manufacturing cost due to difficulty in manufacturing the frame body but also difficulty in deformation of the frame body itself, so that securing airtightness may be difficult. In consideration thereof, in the light-emitting device <NUM>, the frame body <NUM> with a small thickness for releasing stress and the plate bodies <NUM> with a great thickness for fixing the lead terminals <NUM> are disposed as separate members, so that airtightness can be secured while achieving cost reduction.

In the description below, each member included in the light-emitting device <NUM> will be described.

As shown in <FIG>, the package <NUM> used in the light-emitting device <NUM> includes the base body <NUM>, the frame body <NUM>, the lead terminals <NUM>, the plate bodies <NUM>, and the fixing members <NUM>. <FIG> shows a schematic side view of the package <NUM>.

The base body <NUM> is a member on which the light-emitting elements <NUM> and the like can be mounted. Typically, the lower surface 12B of the base body <NUM> is thermally connected to a heat sink or the like and serves as a heat radiation surface for dissipating heat of the light-emitting element <NUM>. While the base body <NUM> may be a member with a flat plate shape, the base body <NUM> preferably has a protrusion that protrudes upward as shown in <FIG> and <FIG>. The protrusion is formed at a position surrounded by the frame body <NUM>, and a region corresponding to an upper surface of the protrusion in the upper surface 12A is to be used as a mounting surface on which the light-emitting element <NUM> and the like are mounted. With such a protrusion, a thickness of the base body <NUM> can be increased at a portion having the protrusion, and thus warpage of the base body <NUM> can be reduced. Further, members such as the light-emitting elements <NUM> may be arranged on the protrusion, which allows the members to be arranged close to the cover <NUM>. With this arrangement, an optical path length of light emitted by the light-emitting elements <NUM> to the cover <NUM> can be shortened, so that a spread of light on a light incident surface of the cover <NUM> can be reduced.

A ceramic material or a metal material can be used for the base body <NUM>. A metal material is preferably used in order to improve heat radiation. Examples of such a metal material include iron, iron alloys, copper, and copper alloys. In addition, one or more through-holes 12c for inserting screws may be defined in the base bodies <NUM>. A plurality of the through-holes 12c may be defined in the base bodies <NUM>, and by fitting a screw into each through-hole 12c, the base body <NUM> can be fixed to a heat sink or the like.

The frame body <NUM> is bonded to the upper surface 12A of the base body <NUM>. A region surrounded by the frame body <NUM> serves as a region for mounting the light-emitting elements <NUM> and the like. The frame body <NUM> is bonded to the base body <NUM> so that bonding the cover <NUM> with the frame body <NUM> allows the light-emitting element <NUM> and the like to be hermetically sealed. In the package <NUM>, the frame body <NUM> is bonded to surfaces of the base body <NUM> around the protrusion.

The lead terminals <NUM> need not be fixed to the frame body <NUM>. Therefore, the frame body <NUM> can have a thickness smaller than a thickness of the plate body <NUM>. The thickness of the frame body <NUM> can preferably be in a range of <NUM> to <NUM>, and more preferably in a range of <NUM> to <NUM>. The "thickness of the frame body <NUM>" is, in other words, a distance between corresponding outer lateral surfaces 14A and inner lateral surfaces 14B. Because the lead terminals <NUM> need not be fixed to the frame body <NUM>, an inexpensive material that can be easily processed can be used for the frame body <NUM>. Accordingly, the cost of the package <NUM> can be reduced. Examples of a material of the frame body <NUM> include steel plate cold (SPC). Compared to KOVAR®, SPC can be more easily processed into a shape of the frame body <NUM> and can be manufactured more inexpensively.

As shown in <FIG>, among others, the frame body <NUM> includes an upper peripheral portion 14d that bends outward above the plate bodies <NUM>. Because a thickness of the frame body <NUM> is reduced, if the frame body <NUM> does not have the upper peripheral portion 14d, a region for bonding the cover <NUM> to the frame body <NUM> cannot be secured and the cover <NUM> and the frame body <NUM> may not be firmly bonded to each other. In view of this, with the frame body <NUM> having the upper peripheral portion 14d bonded to the cover <NUM> via a relatively large area, the upper peripheral portion 14d and the cover <NUM> can be firmly bonded to each other. For example, the upper peripheral portion 14d may have a length in a range of <NUM> to <NUM>. In the present embodiment, the upper peripheral portion 14d bends outward in a direction approximately perpendicular with respect to the outer lateral surface 14A. The expression "bend outward" refers to bending along a direction from the inner lateral surfaces 14B toward the outer lateral surfaces 14A, and the expression "bend inward" refers to bending along a direction from the outer lateral surfaces 14A toward the inner lateral surfaces 14B. The frame body <NUM> can also have an upper peripheral portion that bends inward above the plate bodies <NUM>.

As shown in <FIG>, among others, the upper peripheral portion 14d is preferably spaced from the plate bodies <NUM>. With the upper peripheral portion 14d spaced from the plate bodies <NUM> and not in contact with the plate body <NUM>, the frame body <NUM> can be more easily deformed at a portion in the vicinity of a bending part, so that stress applied to the cover <NUM> can be easily reduced.

In the package <NUM>, as shown in <FIG>, the upper peripheral portion 14d is bent outward and the plate bodies <NUM> are bonded to the outer lateral surfaces 14A of the frame body <NUM>. In this manner, with the arrangement of the plate bodies <NUM> below the upper peripheral portion 14d, upsizing of the package <NUM> can be prevented. For example, the upper peripheral portion 14d has a size that allows the upper peripheral portion 14d to cover and hide a large portion of the plate bodies <NUM> in a top view as shown in <FIG>.

Further, as shown in <FIG>, the frame body <NUM> includes a lower peripheral portion 14e that bends inward below the plate bodies <NUM>. In this case, the frame body <NUM> is bonded to the base body <NUM> at the lower peripheral portion 14e. Accordingly, even with the frame body <NUM> with a small thickness, a bonding area between the frame body <NUM> and the base body <NUM> can be increased, so that the frame body <NUM> and the base body <NUM> can be more firmly bonded to each other. The frame body <NUM> and the base body <NUM> are bonded using a bonding material such as silver solder. A lower surface of the lower peripheral portion 14e may have an area smaller than an area of an upper surface of the upper peripheral portion 14d. In the present embodiment, the lower peripheral portion 14e bends inward in a direction approximately perpendicular with respect to the inner lateral surfaces 14B. The frame body <NUM> can also include a lower peripheral portion that bends outward below the plate body <NUM>.

In the case where the frame body <NUM> includes both the upper peripheral portion 14d and the lower peripheral portion 14e, with the upper peripheral portion 14d and the lower peripheral portion 14e that are arranged in orientations different from each other, the frame body <NUM> can be manufactured more easily compared with the case where the upper peripheral portion 14d and the lower peripheral portion 14e are arranged in the same orientation. Therefore, for example, the upper peripheral portion 14d is preferably bent outward and the lower peripheral portion 14e is bent inward as in the present embodiment.

For example, the frame body <NUM> has an approximately rectangular outer shape in a top view, as shown in <FIG>. In this case, as shown in <FIG> and <FIG>, the frame body <NUM> includes a first outer lateral surface <NUM>, a second outer lateral surface <NUM>, a third outer lateral surface <NUM>, and a fourth outer lateral surface <NUM>. The second outer lateral surface <NUM> is on an opposite side of the first outer lateral surface <NUM> and the fourth outer lateral surface <NUM> is on an opposite side of the third outer lateral surface <NUM>. The expression "approximately rectangular shape" include a rectangular shape and a shapes created by rounding one or more corners of a rectangle. In the package <NUM>, as shown in <FIG> and <FIG>, in a top view, the frame body <NUM> has a shape created by rounding all of the corners of a rectangle. In the package <NUM>, the plate bodies <NUM> are respectively bonded to the first outer lateral surface <NUM> and the second outer lateral surface <NUM>.

In this arrangement, the through-holes 12c of the base body <NUM> described above are preferably defined at both sides of the frame body <NUM> in a direction intersecting the third outer lateral surface <NUM> and the fourth outer lateral surface <NUM> in a top view. Accordingly, a deformation of the base body <NUM> during screwing can be prevented. In other words, when the base body <NUM> is screwed to a heat sink or the like, a screw allows a periphery of the through-holes 12c to sink downward and, relatively, a portion between the through-holes 12c to rise upward. When a degree of such deformation of the base body <NUM> is increased, the frame body <NUM> is partially separated from the base body <NUM>, which creates gaps. With the plate bodies <NUM> bonded to the first outer lateral surface <NUM> and the second outer lateral surface <NUM>, respectively, deformation of the base body <NUM> due to such screwing may be reduced.

For example, each of the first through-holes 14c is provided for each of the lead terminals <NUM>. In the case of disposing a plurality of lead terminals <NUM> on one lateral surface of the frame body <NUM>, a plurality of first through-holes 14c may be provided in the same number as that of the lead terminals <NUM>. With this arrangement, compared with a case where a single first through-hole 14c is provided with respect to a plurality of lead terminals <NUM>, a region in which the first through-hole 14c is not formed on the frame body <NUM> can be increased, so that a bonding area between the frame body <NUM> and the plate bodies <NUM> can be increased.

As shown by dashed lines in <FIG>, the first through-holes 14c are provided with a size and at a position that allows for preventing the first through-holes 14c from contacting with the lead terminals <NUM>. With this arrangement, when the plate bodies <NUM> to which the lead terminal <NUM> is fixed is attached to the frame body <NUM>, a position of the lead terminals <NUM> can be adjusted by adjusting a position of the plate bodies <NUM>. Further, even if the position of the lead terminal <NUM> is deviated from a design value, each of the lead terminals <NUM> can be inserted into respective one of the first through-holes 14c. The first through-holes 14c can have a maximum width larger than a maximum width of the second through-holes 16a. In the case of disposing a plurality of lead terminals <NUM> on one lateral surface of the frame body <NUM>, an opening of each of the first through-holes 14c can have a shape that is elongated in a direction connecting the lead terminals <NUM> to each other. The opening of the first through-hole 14c has a shape of, for example, a stadium shape, that is, a shape created by equally dividing an approximate circle into approximate semicircles and connecting the semicircles with an approximate rectangle disposed between the semicircles.

The frame body <NUM> can have a substantially uniform thickness. This allows for facilitating manufacturing of the frame body <NUM>. The expressions "a thickness of the upper peripheral portion 14d" and "a thickness of the lower peripheral portion 14e" refer to a width in a direction perpendicular to a bending direction in a cross-sectional view. In the case where thermal expansion coefficients of the frame body <NUM> and that of the base body <NUM> are different from each other, warpage occurs when the frame body <NUM> is heated and bonded to the base body <NUM> using a bonding material such as silver solder and then cooled. In this case, the lower surface 12B of the base body <NUM> and an upper surface of the frame body <NUM> are preferably planarized by polishing or the like so that these surfaces are flat surface or approximately flat surfaces. For example, the lower surface 12B that is warped such that a central portion thereof has a height greater than that of an outer peripheral part thereof is polished using a polishing plate until the height of the central part and the height of the outer peripheral part become similar. Accordingly, the lower surface 12B can be planarized, which allows the lower surface 12B to be more easily fixed to a heat sink, etc. In a similar manner, planarizing the upper surface of the frame body <NUM> allows the upper surface to be more easily bonded to the cover <NUM>. Planarizing the frame body <NUM> including the upper peripheral portion 14d allows a thickness of the upper peripheral portion 14d to become uneven. For example, in the case where the frame body <NUM> having an outermost shape of a rectangular shape in a top view is planarized, the thickness of the upper peripheral portion 14d is reduced the closer to a central portion of a side of the rectangular shape. As described above, by partially thinning the upper peripheral portion 14d, the frame body <NUM> can be made more easily deformed compared with before the planarization process, and a strength of the frame body <NUM> can be improved compared with the case where a thickness of the frame body <NUM> is reduced to be a uniform thickness. A thickness reduced by planarization is, for example, <NUM> to <NUM>.

The lead terminals <NUM> serve to electrically connect the light-emitting element <NUM> to the outside. The lead terminals <NUM> are fixed to the plate bodies <NUM> via the fixing members <NUM>. The lead terminals <NUM> are not provided on the lower surface 12B of the base body <NUM>, so that substantially an entire surface of the lower surface 12B of the base body <NUM> can serve as a heat dissipation surface. Accordingly, the light-emitting device <NUM> with good heat dissipation can be provided even in the case where a plurality of the light-emitting elements <NUM> that serve as a heat source is disposed on a single package <NUM>. Examples of a material of the lead terminals <NUM> include KOVAR® and iron-nickel alloys. For example, the lead terminals <NUM> are made of metal.

For the lead terminals <NUM>, a plurality of pairs of a single anode side terminal and a single cathode side terminal are preferably provided. With this arrangement, as shown in <FIG>, a plurality of arrays of the light-emitting elements <NUM> connected in series can be provided.

In the lead terminals <NUM>, each of the pairs of the anode side terminal and the cathode side terminal can be disposed such that the anode side terminal and the cathode side terminal penetrate different lateral surfaces of the frame body <NUM>, respectively. In the package <NUM>, as shown in <FIG>, a single anode-side lead terminal <NUM> and a single cathode-side lead terminal <NUM> are disposed in a straight line.

In the light-emitting device <NUM>, the plate bodies <NUM> are bonded to the outer lateral surfaces 14A of the frame body <NUM>. More specifically, the plate bodies <NUM> are bonded to portions of the outer lateral surfaces 14A of the frame body <NUM>. The plate body <NUM> is not limited to be connected only to the outside surface 14A of the frame body <NUM>. Rather, each of the plate bodies <NUM> is bonded to at least one of the outer lateral surface 14A and the inner lateral surface 14B of the frame body <NUM>.

The second through-holes 16a are defined in each of the plate bodies <NUM>, and the lead terminals <NUM> are inserted into the second through-holes 16a. A penetrating direction of the second through-holes 16a is the same as the penetrating direction of the first through-holes 14c. In this case, the expression "the penetrating direction of the first through-holes 14c and the penetrating direction of the second through-holes 16a is the same" refers to that, in a state where the plate bodies <NUM> are bonded to the frame body <NUM>, each of the first through-holes 14c is connected to each of the second through-holes 16a, and each single lead terminal <NUM> can be inserted into both each of the first through-holes 14c and each of the second through-holes 16a. In each of the plate bodies <NUM>, an inner wall defining each of the second through-holes 16a may have an inclination angle with respect to a main surface thereof may differ from an inclination angle of an inner wall of the first through-hole 14c with respect to a main surface (i.e., the outer lateral surface 14A or the inner lateral surface 14B) of the frame body <NUM>. On the other hand, in the package <NUM>, these inclination angles are both vertical and equal to each other.

Each of the second through-holes 16a is provided for each of the lead terminals <NUM>. Accordingly, a space between each of the lead terminals <NUM> and each of the plate bodies <NUM> can be reliably sealed with the fixing member <NUM>. In the package <NUM>, plate bodies <NUM> are bonded to two opposing outer lateral surfaces of the frame body <NUM>, respectively, a plurality of second through-holes 16a are defined in each of the plate bodies <NUM>, and lead terminals <NUM> are respectively arranged in each of the second through-holes 16a. For example, each of the second through-holes 16a have an opening in a surface with a greatest area among the surfaces of each of the plate bodies <NUM>.

Each of the plate bodies <NUM> has a thickness larger than that of the frame body <NUM>. An example of a specific range of the thickness of each of the plate bodies <NUM> is around <NUM> to <NUM>. With the thickness of each plate body <NUM> of <NUM> or more, the lead terminal <NUM> can be fixed more firmly and the package <NUM> can be obtained in which a gap connecting one opening to another opening of the second through-hole 16a is less likely to be created. For example, the thickness of each plate body <NUM> is twice the thickness of the frame body <NUM> or more. In this case, the "thickness of each of the plate bodies <NUM>" refers to a thickness of each of the plate bodies in the direction of penetration of the second through-holes 16a. In the package <NUM>, the thickness of each of the plate bodies <NUM> is equal to a shortest distance between one opening and the other opening of each of the second through-holes 16a. Examples of a material of the plate bodies <NUM> include metal materials such as KOVAR®. It is preferable that each of the plate bodies <NUM> does not have a bent shape similar to that of the upper peripheral portion 14d of the frame body <NUM> and the like. With such a shape, the plate bodies <NUM> can be easily manufactured. For example, each of the plate bodies <NUM> has a substantially rectangular parallelepiped shape. In other words, the shape of the plate body <NUM> may be a rectangular parallelepiped or a shape created by rounding one or more corners of a rectangular parallelepiped shape. The plate bodies <NUM> and the frame body <NUM> are bonded using a bonding material such as silver solder. The plate bodies <NUM> may be bonded to the base body <NUM>. Accordingly, even if the frame body <NUM> partially separated from the base body <NUM> and a gap is created, the gap is unlikely to connect the inside and the outside of a sealed space. The plate bodies <NUM> and the base body <NUM> are bonded using a bonding material such as silver solder.

An inside of each of the second through-holes 16a of each of the plate bodies <NUM> is filled with the fixing member <NUM> to fix each of the lead terminals <NUM>. According to the claimed invention, the plate bodies <NUM> are made of a conductive material such as metal, the fixing member <NUM> is made of an insulating material. For example, the fixing member <NUM> is made of a glass material. In order to hermetically seal the light-emitting elements <NUM>, a material with a thermal expansion coefficient that is relatively close to those of the plate bodies <NUM> and the lead terminals <NUM> is preferably used for the fixing member <NUM>. Examples of such a material include borosilicate glass. In the package <NUM>, the fixing member <NUM> is pressure-joined with the each of the plate bodies <NUM> and each of the lead terminals <NUM>.

<FIG> is a schematic plan view showing a state where the light-emitting elements <NUM> are arranged on the base body <NUM>. As shown in <FIG>, the light-emitting elements <NUM> are mounted on the upper surface 12A of the base body <NUM>. The expression "the light-emitting element <NUM> are mounted on the upper surface 12A" includes not only the case where the light-emitting elements <NUM> are directly bonded to the upper surface 12A but also the case where the light-emitting elements <NUM> are fixed to the upper surface 12A via another member. In the light-emitting device <NUM>, as shown in <FIG>, submounts <NUM> are fixed to the upper surface 12A and each of the light-emitting elements <NUM> is fixed to each of the submounts <NUM>.

The light-emitting device <NUM> may include a plurality of light-emitting elements <NUM>. The larger the number of the light-emitting elements <NUM> included in the light-emitting device <NUM> is, the larger an amount of heat generation when being driven is, and the larger a stress due to temperature change is applied. However, with a structure in which the plate bodies <NUM> each having a greater thickness are provided in addition to the frame body <NUM> and the lead terminals <NUM> are fixed to the plate bodies <NUM> as described above, a possibility of a decrease in airtightness can be reduced even in the light-emitting device <NUM> having large amount of heat generation. For example, the number of the light-emitting elements <NUM> is four or more and can be in a range of <NUM> to <NUM>.

More specifically, in the light-emitting device <NUM>, the plurality of light-emitting elements <NUM> are arranged in a matrix pattern in a row direction (i.e., an X direction in <FIG>) and a column direction (i.e., a Y direction in <FIG>). In the case of arranging the light-emitting elements <NUM> via the submount <NUM>, a material having a thermal expansion coefficient between that of the base body <NUM> and that of the light-emitting elements <NUM> can be used for a material of the submount <NUM>. Accordingly, stress generated due to a temperature change can be reduced.

In the light-emitting device <NUM>, the light-emitting elements <NUM> are semiconductor laser elements. Examples of semiconductor laser elements include those including an active layer made of a nitride semiconductor. In the case of using such semiconductor laser elements, emitted laser light is likely to cause dust accumulation, and thus the semiconductor laser element is preferably hermetically sealed. With the light-emitting device <NUM>, a decrease in airtightness can be prevented, so that dust accumulation can be reduced. Examples of a nitride semiconductor include group III-V semiconductors such as AlxInyGa<NUM>-x-yN (<NUM> ≤ x ≤ <NUM>, <NUM> ≤ y ≤ <NUM>, <NUM> ≤ x + y ≤ <NUM>). For example, each of the semiconductor laser elements includes a substrate, a semiconductor stack in which an n-type semiconductor layer, an active layer, and a p-type semiconductor layer are layered on the substrate in this order, an n-electrode electrically connected to the n-type semiconductor layer, and a p-electrode electrically connected to the p-type semiconductor layer.

Each of the plurality of semiconductor laser elements emits laser light. The laser light emitted from each semiconductor laser elements is extracted to the outside from the cover <NUM> either directly or via a mirror <NUM> or the like. A phosphor-containing member may be arranged on an optical path of a laser light to extract fluorescence excited by the laser light to the outside. For example, semiconductor laser elements with a high output of <NUM> W or higher are used for the light-emitting elements <NUM>. In the case where a plurality of such a high-output semiconductor laser elements are arranged, a material with high thermal conductivity such as a copper alloy is preferably used for the base body <NUM>. Although such a material has a large thermal expansion coefficient and stress caused by a temperature change is tend to be increased, in the light-emitting device <NUM>, airtightness is less likely to decrease even if relatively large stress is applied. Therefore, the light-emitting device <NUM> including a plurality of high-output semiconductor laser elements can be realized.

The plurality of light-emitting elements <NUM> can be electrically connected to each other by wires <NUM> or the like. For the wires <NUM>, gold, copper, aluminum, or the like can be used. For a connecting manner, for example, a plurality of light-emitting elements <NUM> disposed in the row direction (i.e., the X direction in <FIG>) can be directly connected using the wires <NUM>.

In <FIG>, the plurality of light-emitting elements <NUM> in each row are arranged on a straight line and intermediate members <NUM> are each disposed between adjacent light-emitting elements <NUM>. Further, adjacent light-emitting elements <NUM> are electrically connected to each other by the wires <NUM> via each of the intermediate members <NUM>. With this arrangement, a length of each wire <NUM> can be relatively shortened, so that an increase in electric resistance can be prevented. Furthermore, a distance between adjacent light-emitting elements <NUM> can be increased in each row, so that thermal interference between the light-emitting elements <NUM> can be reduced. For each of the intermediate members <NUM>, a metal member such as iron, iron alloys, or copper may be used, or an insulating member such as AlN, SiC, or SiN and an electric wiring formed on an upper surface thereof may be used. The light-emitting elements <NUM> are not arranged on the intermediate members <NUM>. Each of the intermediate members <NUM> preferably has an upper surface positioned at a height substantially the same as that of an upper surface of each of the submounts <NUM> or an upper surface of each of the light-emitting elements <NUM>. With this arrangement, the wires <NUM> can be easily connected to the respective components.

As shown in <FIG>, the light-emitting device <NUM> may further include mirrors <NUM>. In this case, the light-emitting elements <NUM> are semiconductor laser elements. The mirrors <NUM> are arranged such that a light-emitting surface of each of the semiconductor laser elements to emit a laser light faces an inclined surface of respective one of the mirrors <NUM>. A plurality of mirrors each elongated in the row direction (i.e., the X direction in <FIG>) may be arranged in column, or a plurality of mirrors <NUM> may be arranged in a matrix pattern corresponding to the semiconductor laser elements. Each of the mirrors <NUM> includes a reflecting surface to reflect a laser light emitted by the semiconductor laser element. Each of the mirrors <NUM> includes, for example, a base including a mounting surface and an inclined surface inclined with respect to the mounting surface, and a reflective film disposed on the inclined surface of the base. Glass, synthetic quartz, silicon, sapphire, aluminum, or the like can be used for the base of the mirror <NUM>, and a metal film, a dielectric multilayer film, or the like can be used for the reflective film of the mirror <NUM>.

The cover <NUM> is bonded to the frame body <NUM>. Accordingly, the light-emitting element <NUM> can be hermetically sealed. The cover <NUM> includes a transmissive member <NUM> for extracting light from the light-emitting element <NUM> to the outside. As shown in <FIG>, the cover <NUM> includes a main body portion <NUM> having a plurality of windows 82a and the transmissive member <NUM>. The plurality of windows 82a are each provided at a position from which light emitted by respective one of the plurality of light-emitting elements <NUM> (for example, laser light emitted by each of the semiconductor laser elements) can be extracted.

For the main body portion <NUM>, glass, metal, ceramics, or a material combining these materials can be used and, preferably, a metal is used. Using metal for the main body section <NUM> allows the frame body <NUM> and the cover <NUM> to be fixed to each other by welding or the like, so that hermetic sealing can be easily achieved. For the transmissive member <NUM>, a member that transmits at least a portion of light emitted inside a sealed space enclosed by the package <NUM> and the cover <NUM> is used. For example, a member configured to transmit light emitted by the light-emitting element <NUM> is used. In the case of arranging a phosphor-containing member to be excited by light emitted by the light-emitting element <NUM>, a member configured to transmit at least fluorescence from the phosphor-containing member is used for the transmissive member <NUM>.

The main body portion <NUM> may include one window 82a with respect to two or more light-emitting elements <NUM>, but it is preferable that the main body portion <NUM> includes windows 82a such that each of the windows corresponds to a respective one of the plurality of light-emitting elements <NUM>. With this arrangement, a bonding area between the main body portion <NUM> and the transmissive member <NUM> can be comprehensively increased, so that cracking of the transmissive member <NUM> due to stress can be reduced.

In the light-emitting device <NUM>, a lens member including a lens portion may be further arranged on the cover <NUM>. The cover <NUM> can have a structure that also functions as the lens member. However, in the case where the cover <NUM> is fixed to the frame body <NUM> by welding, the welding may cause displacement, so that it is difficult to arrange the lens portion at a designed position. In order to seal a space in which the light-emitting elements <NUM> are arranged, a member that covers the package <NUM> is preferably fixed by welding. Accordingly, the cover <NUM> and the lens member are preferably provided as separate members. With this arrangement, while the cover <NUM> can be fixed to the frame body <NUM> by welding, the lens member can be fixed to the cover <NUM> using an adhesive or the like. Accordingly, displacement of the lens member can be reduced while the space in which the light-emitting elements <NUM> are arranged can be sealed using the cover <NUM>.

Claim 1:
A package (<NUM>) for a light-emitting device (<NUM>), the package (<NUM>) comprising:
a base body (<NUM>) including an upper surface and a lower surface;
a frame body (<NUM>) bonded to the upper surface of the base body (<NUM>), the frame body (<NUM>) including one or more outer lateral surfaces, one or more inner lateral surfaces, and one or more first through-holes that extend through the frame body (<NUM>) in a lateral direction so as to connect an inside and an outside of the frame body (<NUM>);
one or more lead terminals (<NUM>), each of which extends through a respective one or the one or more first through-holes;
one or more plate bodies (<NUM>), each of which is bonded to a respective one of the one or more outer lateral surfaces or a respective one of the one or more inner lateral surfaces of the frame body (<NUM>), each of the one or more plate bodies (<NUM>) having one or more second through-holes that extend through the plate body (<NUM>) in the lateral direction, wherein each of the one or more lead terminals (<NUM>) extends through a respective one of the one or more second through-holes, and wherein a thickness of each of the one or more plate bodies (<NUM>) is larger than a thickness of the frame body (<NUM>), and wherein each of the one or more plate bodies (<NUM>) is made of a conductive material, and wherein the frame body (<NUM>) includes an upper peripheral portion that is bent inward or outward above the one or more plate bodies (<NUM>); and
one or more fixing members (<NUM>), each of which is disposed in a respective one of the one or more second through-holes and fixes a respective one of the one or more lead terminals (<NUM>) in a respective one of the one or more plate bodies (<NUM>), and wherein the one or more fixing members (<NUM>) are made of an insulating material.