Light-emitting device

Abstract

A light-emitting device is provided. The light-emitting device has: a substrate, on which a power supply wiring pattern and a frame-shaped bonding frame pattern are formed, the power supply wiring pattern includes: a first metal pad formed in an area on the surface of the substrate; a second metal pad formed in an area separated from the first metal pad; a first metal wiring extending from the first metal pad to the outside of the area on the surface; and a second metal wiring extending from the second metal pad to the outside of the area and separated from the first metal pad and the first metal wiring, the bonding frame pattern is separated from the power supply wiring pattern and surrounds the power supply wiring pattern; a light-emitting element mounted on an area on the surface of the substrate via the first metal pad and the second metal pad; and a sealing component, on the bottom surface of which a frame-shaped sealing bonding component opposite to the bonding frame pattern is formed, and the sealing component is bonded to the substrate by pressing and melting the sealing bonding component and the bonding frame pattern.

Description

Technical Field

[0001] The present invention relates to a light-emitting device including a light-emitting element. Background Art

[0002] In the past, there is a known technique for airtightly sealing a wiring substrate via solder. For example, Patent Document 1 discloses a surface acoustic wave device having a surface acoustic wave element mounted on a substrate and a contamination prevention wall arranged around the element, and a metal cover for airtightly sealing the surface acoustic wave element and the contamination prevention wall via solder. In addition, Patent Document 2 discloses a ceramic wiring substrate having a sealing land electrode (land) formed thereon, and a metal cover having a metal cover joint portion formed by processing the periphery of an open end, and airtightly sealing the sealing land electrode via solder.

[0003] [Prior art literature]

[0004] [Patent Document]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 6-216698

[0006] [Patent Document 2] Japanese Patent Application Laid-Open No. 7-202449 Summary of the invention

[0007] [Problems to be Solved by the Invention]

[0008] For example, in a device such as Patent Document 1, consider a case where a cover is joined to a wiring substrate via solder to hermetically seal the element as in Patent Document 2. In this case, when the solder is melted by heating while applying a load to the cover, the molten solder enters a gap provided between the wiring substrate and the joint portion of the cover, but the remaining solder overflows from the gap toward the element on the wiring substrate and wets and spreads to the wiring connected to the element, which is considered to be one of the problems.

[0009] When such problems occur, for example, short circuits may occur between wirings connected to the elements or insufficient solder may cause airtightness failure at the junction between the wiring board and the cover, which may affect the yield rate during device manufacturing.

[0010] The present invention is completed in view of the above-mentioned problems, and its purpose is to provide a light-emitting device that can prevent solder from wetting and spreading onto the wiring when a cover for airtightly sealing the semiconductor element is joined to a wiring substrate equipped with a semiconductor element such as a light-emitting element, thereby preventing defects from occurring during manufacturing.

[0011] [Methods for solving the problem]

[0012] The light emitting device of the present invention is characterized in that it has: a substrate having a power supply wiring pattern and a frame-shaped bonding frame pattern, wherein the power supply wiring pattern includes: a first metal pad formed in a region on the surface of the substrate; a second metal pad formed in the region and separated from the first metal pad; a first metal wiring extending from the first metal pad to the outside of the region on the surface; and a second metal wiring extending from the second metal pad to the outside of the region and separated from the first metal pad and the first metal wiring, wherein the bonding frame pattern is separated from the power supply wiring pattern and surrounds the power supply wiring pattern; and a light emitting element mounted via the first metal pad and the second metal pad. The sealing component is formed on the bottom surface of the sealing component and is bonded to the substrate by crimping and melting the sealing component and the bonding frame pattern, and the sealing component seals the power supply wiring pattern and the light-emitting element. On the surface of the substrate, at least a portion of the surface of either the first metal wiring or the second metal wiring is covered by a covering film, which is separated from the bonding frame pattern and is composed of a metal material having a surface that is less wettable to the material of the sealing component than the upper surfaces of the first metal wiring and the second metal wiring. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a three-dimensional diagram of the light emitting device of Example 1.

[0014] Figure 2 This is a top view of the light-emitting device of Example 1.

[0015] Figure 3 This is a cross-sectional view of the light emitting device of Example 1.

[0016] Figure 4 This is a three-dimensional diagram of the light-emitting device of Example 2.

[0017] Figure 5 This is a top view of the light-emitting device of Example 2.

[0018] Description of symbols

[0019] 10, 20 Light-emitting device

[0020] 11 substrate

[0021] 13 Light-emitting element

[0022] 15 Zener diode

[0023] 17 Sealing cover

[0024] 21, 41 1st metal pad

[0025] 22, 42 2nd metal pad

[0026] 43 3rd metal pad

[0027] 44 4th metal pad

[0028] 45 5th Metal Pad

[0029] 46 6th metal pad

[0030] 47 7th Metal Pad

[0031] 48 8th Metal Pad

[0032] 23, 55 1st metal wiring

[0033] 24, 56 Second Metal Wiring

[0034] 26, 58 1st metal film

[0035] 27, 59 2nd metal film

[0036] 29-joined frame pattern

[0037] 31 1st lower surface electrode

[0038] 32 2nd lower surface electrode

[0039] 34 Metallization pattern

[0040] 35 Sealing joint parts

[0041] 51 1st intermediate wiring

[0042] 52 2nd intermediate wiring

[0043] 53 3rd intermediate wiring

[0044] 54 4th intermediate wiring

[0045] 61 1st separator

[0046] 62 Second separation membrane DETAILED DESCRIPTION

[0047] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, in the accompanying drawings, the same components are denoted by the same reference numerals, and the description of the repeated components is omitted.

[0048] [Example 1]

[0049] Figure 11 is a perspective view of the light emitting device 10 of Example 1. The substrate 11 is a flat plate substrate with a square top surface. The substrate 11 is made of aluminum nitride (AlN) or aluminum oxide (Al 2 O 3 ), silicon nitride (Si 3 N 4 ) and other insulating ceramic substrates.

[0050] The light emitting element 13 is arranged at the approximate center of the upper surface of the substrate 11, and is a light emitting element having a rectangular upper surface shape. In the present embodiment, the light emitting element 13 is a flip chip type light emitting diode (LED) that emits light in the wavelength range of the ultraviolet region from the upper surface. The light emitting element 13 is composed of a supporting substrate and a photoelectric conversion layer composed of an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer (none of which are shown in the figure).

[0051] The protection element 15 is an element whose upper surface is rectangular. The protection element 15 is separated from the light emitting element 13 on the upper surface of the substrate 11 and the long side extends parallel to one side of the light emitting element 13. In the present embodiment, the protection element 15 is a Zener diode (ZD), which protects the light emitting element 13 from the surge current that flows in a momentary state exceeding the steady state during the process of supplying power from the outside to drive the light emitting element 13, and can obtain a constant voltage.

[0052] The sealing cover 17 is a sealing member disposed on the upper surface of the substrate 11 and covers the light emitting element 13 and the protective element 15 on the substrate 11. In this embodiment, the sealing cover 17 is made of glass and has a recess capable of housing the light emitting element 13 and the protective element 15.

[0053] The frame portion 17A of the sealing cover 17 is a square frame-shaped portion having a bottom surface facing the upper surface of the substrate 11 and is bonded to the substrate 11. The outer edge of the frame portion 17A is substantially the same as the outer edge of the substrate 11.

[0054] The lens portion 17B (or also referred to as the window portion 17B) as the light-transmitting portion in the sealing cover 17 is a convex portion that stands up from the inner side of the frame portion 17A and protrudes upward from the upper surface of the frame portion 17A. The lens portion 17B has a dome shape, which allows the light emitted from the light-emitting element 13 to be transmitted to the outside of the sealing cover 17. In the present embodiment, the lens portion 17B has a dome shape with a uniform thickness. The lens portion 17B can also be set to a shape that focuses or diffuses the light emitted from the light-emitting element 13.

[0055] In addition, the sealing cover 17 can also be formed by etching one side of a rectangular glass to have a concave shape, and the concave can accommodate the light emitting element 13 and the protective element 15. In this case, the bottom surface of the concave becomes the window portion 17B, and the outer periphery defining the concave becomes the frame portion 17A. In addition, the sealing cover 17 can also be formed by welding a frame-shaped glass frame to become the frame portion 17A on a square glass plate to become the window portion 17B.

[0056] The sealing cap 17 seals the light emitting element 13 and the protection element 15 , and wiring formed on the substrate 11 for electrically connecting them, in a space on the substrate 11 .

[0057] Figure 2 FIG. 1 is a top view of the light emitting device 10 of Example 1. Figure 2 In order to avoid the complexity of the diagram, the dashed line is used to represent Figure 1 The light emitting element 13 and the protective element 15 described in the embodiment are described with the sealing cover 17 omitted. Figure 2 In FIG. 1 , a center line of the substrate 11 parallel to a pair of opposite sides of the substrate 11 is represented as a center line CL.

[0058] The first metal pad 21 (e.g., anode) and the second metal pad 22 (e.g., cathode) are electrode pads composed of metal layers with rectangular upper surfaces that are separated from each other and arranged approximately in the center of the upper surface of the substrate 11. The first metal pad 21 includes a pad 21A and a pad 21B. The pads 21A and 21B are approximately the same size, separated from each other on the upper surface of the substrate 11, and extend parallel to the direction along their respective long sides.

[0059] The second metal pad 22 is an electrode pad composed of a rectangular metal layer disposed between the pad 21A and the pad 21B of the first metal pad 21 and separated from them. The second metal pad 22 has a long strip-shaped upper surface shape whose long sides are extended parallel to the long sides of the pads 21A and 21B. In addition, the second metal pad 22 is disposed on the upper surface of the substrate 11 in a manner sandwiched by the pads 21A and 21B.

[0060] In this embodiment, the upper surfaces of the first metal pad 21 and the second metal pad 22 are bonded to the element electrode pad (not shown) provided on the bottom surface of the light emitting element 13 opposite to the upper surfaces. That is, the area connecting the outer edges of the first metal pad 21 and the second metal pad 22 is the bonding area for bonding the light emitting element 13.

[0061] The first metal pad 21 and the second metal pad 22 are formed by stacking a plurality of metal layers on the substrate 11. In the present embodiment, the first metal pad 21 and the second metal pad 22 are formed by stacking copper (Cu), nickel (Ni), palladium (Pd), gold (Au), and gold-tin (AuSn) alloy on the substrate 11 in this order.

[0062] The first metal wiring 23 is a metal wiring formed on the upper surface of the substrate 11, and is connected to the short sides of the pads 21A and 21B of the first metal pads 21 in the region to the left of the center line CL. The first metal wiring 23 is separated from the second metal pads 22 on the substrate 11 and is electrically insulated.

[0063] The first metal wiring 23 extends in the vertical direction in the figure along the short sides, and further extends toward the center line CL along the long sides of the pads 21A and 21B. That is, the first metal wiring 23 extends around the first metal pad 21 and the second metal pad 22 in the area to the left of the center line CL, and is formed on the substrate 11 in a manner of drawing a C-letter.

[0064] The second metal wiring 24 is a metal wiring formed on the upper surface of the substrate 11, and is connected to the short side of the second metal pad 22 in the area to the right of the center line CL. The second metal wiring 24 is separated from the pads 21A and 21B of the first metal pad 21 and the first metal wiring 23 on the substrate 11 and is electrically insulated.

[0065] The second metal wiring 24 extends along the short sides of the pads 21A and 21B of the first metal pad 21, and further extends toward the center line CL along the long sides of the pads 21A and 21B. That is, the second metal wiring 24 extends around the first metal pad 21 and the second metal pad 22 in the area to the right of the center line CL, and is formed on the substrate 11 in a manner of drawing an inverted C-letter.

[0066] The first metal wiring 23 and the second metal wiring 24 are line-symmetrical about the center line CL. That is, on the substrate 11, the first metal wiring 23 formed in a C shape and the second metal wiring 24 formed in an inverted C shape are matched in a manner separated from each other and facing each other, so that the first metal wiring 23 and the second metal wiring 24 are separated from each other in the portion other than the short side connected to the first metal pad 21 and the second metal pad 22.

[0067] The first metal wiring 23 and the second metal wiring 24 are formed by stacking a plurality of metal layers on the substrate 11. In the present embodiment, the first metal wiring 23 and the second metal wiring 24 are formed by stacking Cu, Ni, Pd, and Au in this order on the substrate 11.

[0068] Hereinafter, in the present embodiment, the first metal pad 21 , the second metal pad 22 , the first metal wiring 23 , and the second metal wiring 24 are collectively referred to as a power supply wiring pattern.

[0069] The light emitting element 13 (framed by a single dotted line) has an element electrode pad of a first polarity (e.g., an anode) and an element electrode pad of a second polarity (e.g., a cathode) on the lower surface, which are respectively bonded to the first metal pad 21 and the second metal pad 22 via AuSn bonding components (not shown).

[0070] The light emitting element 13 is bonded as follows: in a nitrogen atmosphere containing formic acid, a first polarity element electrode pad and a second polarity element electrode pad (not shown) are pressed against the upper surfaces of the corresponding first metal pad 21 and second metal pad 22 and heated.

[0071] Furthermore, when a light-emitting element having element electrode pads of different polarities on the upper and lower surfaces is used, one metal pad corresponding to the polarity of the element electrode pad provided on the lower surface of the light-emitting element is arranged to be opposite to the element electrode pad on the lower surface, and the other metal pad is provided on the upper surface of the metal wiring corresponding to the polarity of the element electrode pad on the upper surface. Then, the element electrode pad on the lower surface of the light-emitting element is bonded to the one metal pad opposite thereto by a bonding component, and the element electrode pad on the upper surface of the light-emitting element is connected to the other metal pad by a metal wire.

[0072] The first metal film 26 covers the first metal wiring 23 in the region to the left of the center line CL and extends to the upper surface region of the substrate 11 outside the first metal wiring 23. In other words, the first metal film 26 covers the shape of the first metal wiring 23 with an area larger than the first metal wiring 23. That is, the first metal film 26 is formed in a manner of describing a C-letter around the first metal pad 21 and the second metal pad 22 in the region to the left of the center line CL.

[0073] The second metal film 27 covers the second metal wiring 24 in the region to the right of the center line CL and extends to the upper surface region of the substrate 11 outside the second metal wiring 24. In other words, the second metal film 27 covers the second metal wiring 24 with an area larger than the second metal wiring 24 along the shape of the second metal wiring 24. That is, the second metal film 27 is formed in the region to the right of the center line CL in a manner that draws an inverted C-letter around the first metal pad 21 and the second metal pad 22.

[0074] The first metal film 26 and the second metal film 27 are cover films separated from each other and from the first metal pad 21 and the second metal pad 22, and respectively cover the first metal wiring 23 and the second metal wiring 24, and are made of metal. In this embodiment, the first metal film 26 and the second metal film 27 are stacked in the order of titanium (Ti) and aluminum (Al), and have a passive film of aluminum oxide film on the surface. The passive film has acid resistance and will not be deteriorated or removed by formic acid used for bonding the light emitting element 13.

[0075] The first metal film 26 and the second metal film 27 expose a portion of the first metal wiring 23 and the second metal wiring 24 , respectively.

[0076] In the present embodiment, the ends of the first metal wiring 23 and the second metal wiring 24 exposed from the ends of the first metal film 26 and the second metal film 27 serve as regions to be bonded to the protection element 15 .

[0077] Parts of the outer peripheral sides of the two ends of the second metal film 27 (27UH and 27DH) extend beyond the center line CL to the vicinity of the outer peripheral ends of the first metal film 26. In this embodiment, the arrangement interval WP between the ends of the first metal film 26 and the ends of the second metal film 27 is set to be 50 μm or more to avoid short circuits. In addition, it is set to be 200 μm or less to prevent the melted sealing bonding member 35 from intruding.

[0078] Through the above arrangement, the first metal film 26 formed in a C shape and the second metal film 27 formed in an inverted C shape are separated and opposed to each other, thereby forming a frame-shaped metal film that covers the first metal wiring 23 and the second metal wiring 24 respectively and surrounds the first metal pad 21 and the second metal pad 22.

[0079] The bonding frame pattern 29 is a frame-shaped metal layer formed around the substrate 11. The bonding frame pattern 29 is separated from the first metal film 26 and the second metal film 27 on the upper surface of the substrate 11, and surrounds the above-mentioned power supply wiring pattern and the first metal film 26 and the second metal film 27. In this embodiment, the bonding frame pattern 29 is formed by stacking metal layers of Cu, Ni, Pd, and Au on the substrate 11 in this order.

[0080] The upper surface of the bonding frame pattern 29 is bonded to the bottom surface of the sealing cover 17 facing the upper surface.

[0081] Figure 3 It is along Figure 2 A cross-sectional view of the light emitting device 10 taken along line 3-3. Figure 3 Including Figure 1 The light emitting element 13 and the sealing cover 17 are shown in the figure.

[0082] As described above, the substrate 11 is a flat insulating member having a rectangular cross section. The first lower surface electrode 31 and the second lower surface electrode 32 are flat metal layers formed separately from each other on the lower surface of the substrate 11. The first metal wiring 23 and the second metal wiring 24 are electrically connected to the first lower surface electrode 31 and the second lower surface electrode 32 respectively via a conductive hole (not shown) made of a conductive metal that penetrates the substrate 11 in the up and down directions.

[0083] In this embodiment, the first metal pad 21, the first metal wiring 23 and the first bottom surface electrode 31 can function as an anode, and the second metal pad 22, the second metal wiring 24 and the second bottom surface electrode 32 can function as a cathode. Therefore, by energizing the first bottom surface electrode 31 and the second bottom surface electrode 32, the light emitting element 13 bonded to the first metal pad 21 and the second metal pad 22 emits light.

[0084] The metallization pattern 34 is a frame-shaped metal layer formed on the bottom surface 17S of the frame body portion 17A of the sealing cover 17. The metallization pattern 34 is formed by stacking metal layers of Ti, Pd, Cu, Ni, and Au in this order from the bottom surface 17S side.

[0085] The sealing bonding member 35 is provided between the metallization pattern 34 and the bonding frame pattern 29 and is a frame-shaped bonding member for bonding the sealing cover 17 to the substrate 11. The sealing bonding member 35 is formed by melting and solidifying a metal molded body (preformed body material) composed of Au-Sn 22wt% alloy.

[0086] The sealing cover 17 is bonded to the bonding frame pattern 29 formed on the upper surface of the substrate 11 via the metallization pattern 34 and the sealing bonding member 35. The sealing cover 17 seals the space formed by the inner side surface (recess) of the frame portion 17A and the lens portion 17B by bonding to the substrate 11, thereby airtightly sealing the light-emitting element 13, the power supply wiring pattern, the first metal film 26, and the second metal film 27 provided on the substrate 11 in the space.

[0087] Here, refer to Figure 3 , the first metal film 26 and the second metal film 27 are described in detail. As described above, the first metal film 26 and the second metal film 27 are metal films that cover the first metal wiring 23 and the second metal wiring 24, respectively, and extend to the outside of the first metal wiring 23 and the second metal wiring 24.

[0088] Specifically, the first metal film 26 and the second metal film 27 extend from the upper surfaces of the first metal wiring 23 and the second metal wiring 24 through the outer side surfaces to the upper surface of the substrate 11 , and are arranged to be separated from the bonding frame pattern 29 by an insulating distance.

[0089] In the present embodiment, the first metal film 26 and the second metal film 27 are composed of Al covering Ti, and a thin dense aluminum oxide film, i.e., a passive film, is formed on the surface thereof. For example, in a substrate 11 having a power supply wiring pattern and a bonding frame pattern 29 formed thereon, after the first metal film 26 and the second metal film 27 are patterned by sputtering, evaporation, etc., the first metal film 26 and the second metal film 27 are left to stand in a normal temperature atmosphere with a humidity of 70% or less, thereby forming the passive film. The humidity is preferably 60% or less. This is because, for example, in an atmosphere with a humidity of 70% or more, aluminum hydroxide and aluminum oxide with low density are locally formed, and the characteristics of the sealing bonding component 35 that repels the melt are reduced.

[0090] On the other hand, Au as a noble metal is disposed on the surfaces of the first metal wiring 23, the second metal wiring 24, the first metal pad 21, and the second metal pad 22 which are not covered by the first metal film 26 and the second metal film 27. That is, no passivation film is formed on the surfaces of the first metal wiring 23, the second metal wiring 24, the first metal pad 21, and the second metal pad 22.

[0091] In this embodiment, the first metal film 26 and the second metal film 27 composed of Al with a passive film formed on the surface have poor wettability to the sealing and bonding component 35 composed of the molten AuSn alloy, and repel the molten AuSn alloy. In addition, the surface of the substrate 11 composed of ceramics also has poor wettability to the molten sealing and bonding component 35, and repel the molten AuSn alloy. However, the surface of the passive film on the first metal film 26 and the second metal film 27 is smoother than the ceramic surface, and therefore easily repel the molten AnSn alloy.

[0092] In contrast, the first metal wiring 23 and the second metal wiring 24 have good wettability to the melted sealing bonding member 35 and are easily wetted by the melted AuSn alloy. The Au layer on the surface melts with the AuSn alloy, and the AuSn alloy solidifies.

[0093] When manufacturing the light emitting device 10 , the sealing cover 17 is heated while applying a load, and the sealing bonding member 35 is melted and solidified to bond the sealing cover 17 to the substrate 11 (compression bonding and melting step).

[0094] Specifically, a sealing bonding component 35 composed of a molded metal body is temporarily fixed to the bottom surface 17S of the sealing cover 17, and is pressed and heated with the bonding frame pattern 29 in a nitrogen atmosphere. At this time, the sealing bonding component 35 composed of an alloy of 22 wt% Au-Sn melts and solidifies at 300°C, and the metallization pattern 34 of the sealing cover 17 is bonded to the bonding frame pattern 29 of the substrate 11.

[0095] In this crimping and melting process, when a load is applied to the sealing cap 17, a portion of the melted sealing bonding member 35 sometimes overflows from the bottom surface 17S of the sealing cap 17, reaches the surface of the first metal wiring 23 and the second metal wiring 24 whose surface is Au, wets, spreads, fuses, and solidifies. In addition, a portion of the melted and overflowed sealing bonding member 35 sometimes separates and becomes small pieces.

[0096] In the light emitting device 10 of the present embodiment, the first metal film 26 and the second metal film 27 cover the first metal wiring 23 and the second metal wiring 24, respectively, so that the sealing bonding component 35 that melts and overflows can be repelled, and it is prevented from wetting, spreading, fusing and solidifying on the surfaces of the first metal wiring 23 and the second metal wiring 24. As a result, it is possible to prevent the first metal wiring 23 and the second metal wiring 24 from being connected and short-circuited due to the melted sealing bonding component 35. In addition, the repelled sealing bonding component 35 returns to between the metallization pattern 34 of the sealing cover 17 and the bonding frame pattern 29 on the substrate 11.

[0097] Furthermore, in the light emitting device 10 of the present embodiment, the first metal film 26 and the second metal film 27 cover the first metal wiring 23 and the second metal wiring 24, respectively, and extend to the upper surface of the substrate 11 and are arranged near the bonding frame pattern 29. Thus, the passive coating of the metal film can be used to repel and push back the melted and overflowing sealing bonding component 35. That is, it is possible to prevent the sealing bonding component 35 required for the bonding of the sealing cover 17 and the substrate 11 from being insufficient. In addition, it is possible to prevent the power supply wiring pattern and the bonding frame pattern 29 from being connected and short-circuited due to the separated small pieces of the sealing bonding component 35.

[0098] In this embodiment, the arrangement interval WR between the first metal film 26 and the second metal film 27 and the bonding frame pattern 29 is set to 100 μm. Considering the alignment deviation of the sealing cover, the arrangement interval WR is preferably 100 μm or more, and preferably 300 μm or less to suppress the overflow of the melted sealing bonding member 35.

[0099] Therefore, in the light emitting device 10 of the present embodiment, the first metal film 26 and the second metal film 27 extend from the upper surfaces of the first metal wiring 23 and the second metal wiring 24 to the upper surface of the substrate 11, and are arranged near the bonding frame pattern 29, thereby preventing the short circuit between the first metal wiring 23 and the second metal wiring 24 and the airtightness failure caused by the lack of bonding parts at the bonding portion between the substrate 11 and the sealing cover 17. That is, in the light emitting device 10 of the present embodiment, it is possible to prevent the occurrence of defects when manufacturing the light emitting device 10.

[0100] In addition, the first metal film 26 and the second metal film 27 can be made of any metal that can form a passive film composed of a metal oxide on the surface. For example, in addition to Al, it can also be Al alloy, Ni, Cr, W, Ti, molybdenum (Mo) and other metals and their alloys. Preferably, a metal that forms a passive film that cannot be removed by formic acid or the like is suitable. In other words, the metal used for the first metal film 26 and the second metal film 27 can be any metal that repels the molten sealing bonding component 35 and is not removed in the bonding atmosphere of the light emitting element 13.

[0101] In addition, the above-mentioned passive film may be formed through a surface treatment process, for example, the thickness of the passive film may be controlled through ozone cleaning and heating processes, thereby forming a more dense passive film than the passive film formed by the above-mentioned static state.

[0102] In addition, the first metal film 26 and the second metal film 27 may be formed by stacking a plurality of metal layers on the substrate 11 and the first metal wiring 23 and the second metal wiring 24, as long as a metal having poor wettability to the sealing and bonding component 35 is formed on the surface. For example, a metal such as Pt as a diffusion prevention layer and Ti as an adhesive layer may be formed under Al having a passivation coating.

[0103] In addition, the metal film composed of the first metal film 26 and the second metal film 27 only needs to cover at least one of the first metal wiring 23 and the second metal wiring 24. Thus, even if the melted sealing and bonding member 35 adheres to the other metal wiring not covered by the metal film and wets and spreads, the melted sealing and bonding member 35 can be prevented from contacting the metal wiring covered by the metal film. That is, the metal film can prevent the melted sealing and bonding member 35 from crossing over the first metal wiring 23 and the second metal wiring 24 and wets and spreads, thereby preventing the two from being conductive.

[0104] At this time, it is preferred that the metal film composed of the first metal film 26 and the second metal film 27 covers at least the first metal wiring 23 that can function as the anode wiring. This is because if the overflowing sealing bonding component 35 crosses the first metal wiring 23 (anode), the bonding portion of the sealing cover 17 becomes a positive potential, and in a high humidity environment, part of the constituent metal of the bonding portion is ionized to cause electrolytic corrosion. In contrast, when crossing the second metal wiring 24 (cathode), the bonding portion of the sealing cover 17 becomes a negative potential, thereby preventing electrolytic corrosion.

[0105] The sealing bonding member 35 provided on the sealing cover 17 may be any structure as long as it is bonded to the substrate 11 by a crimping and melting process. For example, the sealing bonding member 35 before melting may be formed on the bottom surface 17S of the sealing cover 17 by plating treatment in addition to a metal formed body, or may be composed of a plurality of convex protrusions composed of an AuSn alloy.

[0106] [Example 2]

[0107] Next, use Figure 4 and Figure 5 Embodiment 2 is described. Embodiment 2 is different from Embodiment 1 in that four light emitting elements 13A to 13D are provided on the substrate 11, two intermediate wirings are provided on the substrate 11 to connect the four light emitting elements 13A to 13D in series, and two extensions extending from the inner edge to the inner side are provided on the bonding frame pattern 29. Other than this, the structure of the substrate 11, the structure of the sealing cover 17, and the bonding method thereof are the same as those of Embodiment 1. Hereinafter, the differences from Embodiment 1 will be mainly described.

[0108] Figure 4 1 is a perspective view of a light emitting device 20 according to Example 2. As described above, the light emitting elements 13A to 13D are light emitting elements arranged on the upper surface of the substrate 11 . The protection element 15 is a Zener diode arranged at the center of the upper surface of the substrate 11 .

[0109] The light emitting elements 13A to 13D are arranged around the protective element 15 on the upper surface of the substrate 11 so as to surround the protective element 15. On the upper surface of the substrate 11, the light emitting elements 13A and 13D are arranged so as to sandwich the protective element 15. In addition, on the upper surface of the substrate 11, the light emitting elements 13B and 13C are arranged so as to sandwich the protective element 15.

[0110] The sealing cap 17 seals the light emitting elements 13A to 13D, the protection element 15 , and wiring formed on the substrate 11 for electrically connecting them in a space on the substrate 11 , similarly to the first embodiment.

[0111] Figure 5 FIG. 2 is a top view of the light emitting device 20 of Example 2. Figure 5 In order to avoid the complexity of the diagram, the dashed line is used to represent Figure 4 The light emitting elements 13A to 13D and the protective element 15 described in the embodiment are described with the sealing cover 17 omitted. Figure 5 , a center line of the upper surface of the substrate 11 parallel to a pair of opposite sides of the substrate 11 is represented as a center line CL1, and a center line of the upper surface of the substrate 11 perpendicularly intersecting the center line CL1 is represented as a center line CL2.

[0112] In this embodiment, the light emitting element 13A is arranged above the center line CL2 on the substrate 11. The light emitting element 13B is arranged on the right side of the center line CL1 on the substrate 11. The light emitting element 13C is arranged on the left side of the center line CL1 on the substrate 11. The light emitting element 13D is arranged on the substrate 11 below the center line CL2.

[0113] The light emitting elements 13A and 13D are arranged on the substrate 11 so that the center line CL1 passes through a part of each. The light emitting elements 13B and 13C are arranged so that the center line CL2 passes through the center of each. The light emitting elements 13A to 13D are separated from each other on the substrate 11.

[0114] In this embodiment, light emitting elements 13A and 13D are arranged point-symmetrically about the center of the upper surface of substrate 11, that is, the intersection of center lines CL1 and CL2. In this embodiment, light emitting elements 13B and 13C are arranged line-symmetrically about center line CL1.

[0115] The first metal pad 41 and the second metal pad 42 are a pair of electrode pads disposed below the light emitting element 13A and provided separately from each other on the substrate 11. Similarly, the third metal pad 43 and the fourth metal pad 44 are a pair of electrode pads disposed below the light emitting element 13B and provided separately from each other on the substrate 11. In addition, the fifth metal pad 45 and the sixth metal pad 46 are a pair of electrode pads disposed below the light emitting element 13C and provided separately from each other on the substrate 11. In addition, the seventh metal pad 47 and the eighth metal pad 48 are a pair of electrode pads disposed below the light emitting element 13D and provided separately from each other on the substrate 11.

[0116] In this embodiment, the first metal pad 41, the third metal pad 43, the fifth metal pad 45 and the seventh metal pad 47 are formed by a metal layer whose upper surface is substantially square. In addition, the second metal pad 42, the fourth metal pad 44, the sixth metal pad 46 and the eighth metal pad 48 are formed by a metal layer whose upper surface is rectangular.

[0117] As in the first embodiment, the upper surfaces of the pair of electrode pads are bonded to element electrode pads (not shown) provided on the bottom surfaces of the light emitting elements 13A to 13D respectively facing the upper surfaces.

[0118] The first intermediate wiring 51 is a metal wiring that connects the second metal pad 42 and the third metal pad 43 on the upper surface of the substrate 11. The second intermediate wiring 52 is a metal wiring that connects the sixth metal pad 46 and the seventh metal pad 47 on the upper surface of the substrate 11.

[0119] The third intermediate wiring 53 and the fourth intermediate wiring 54 are metal wirings arranged below the protection element 15. The third intermediate wiring 53 and the fourth intermediate wiring 54 extend from the first metal pad 41 and the eighth metal pad 48 toward the center line CL2 on the upper surface of the substrate 11. The third intermediate wiring 53 and the fourth intermediate wiring 54 are arranged to be separated from each other so as to pass through the center line CL1 and face each other across the center line CL2.

[0120] As described in Example 1, the bonding frame pattern 29 is a frame-shaped metal layer formed around the substrate 11. The first extension portion 29E1 in the bonding frame pattern 29 is a portion extending from the inner edge of the bonding frame pattern 29 through the center line CL2 toward the center line CL1 in an area on the right side of the center line CL1 on the substrate 11. In addition, the first extension portion 29E1 is connected to the fourth metal pad 44. That is, the fourth metal pad 44 is connected to the bonding frame pattern 29 via the first extension portion 29E1.

[0121] The second extension portion 29E2 in the bonding frame pattern 29 is a portion extending from the inner edge of the bonding frame pattern 29 through the center line CL2 toward the center line CL1 in the area on the left side of the center line CL1 on the substrate 11. In addition, the second extension portion 29E2 is connected to the fifth metal pad 45. That is, the fifth metal pad 45 is connected to the bonding frame pattern 29 via the second extension portion 29E2.

[0122] The first metal wiring 55 is a metal wiring provided in a region on the upper surface of the substrate 11 on the left side of the center line CL1 and on the upper side of the center line CL2 . The first metal wiring 55 is connected to the first metal pad 41 .

[0123] The first metal wiring 55 extends from one side of the first metal pad 41 in a direction away from the center line CL1, i.e., to the left in the figure. The first metal wiring 55 is separated from the metal pads and wirings other than the first metal pad 41 and the third intermediate wiring 53 on the upper surface of the substrate 11, and is electrically insulated from the metal pads and wirings other than the first metal pad 41 and the third intermediate wiring 53.

[0124] The second metal wiring 56 is a metal wiring provided in a region on the upper surface of the substrate 11 to the right of the center line CL1 and below the center line CL2 . The second metal wiring 56 is connected to the eighth metal pad 48 .

[0125] The second metal wiring 56 extends from one side of the eighth metal pad 48 in a direction away from the center line CL1, i.e., to the right in the figure. The second metal wiring 56 is separated from the metal pads and wirings other than the eighth metal pad 48 and the fourth intermediate wiring 54 on the upper surface of the substrate 11, and is electrically insulated from the metal pads and wirings other than the eighth metal pad 48 and the fourth intermediate wiring 54.

[0126] The first metal film 58 is formed on the upper surface of the substrate 11 in a region above the center line CL2, covers the first metal wiring 55, and extends to a region outside the first metal wiring 55. In other words, the first metal film 58 covers the first metal wiring 55 except for the connection portion with the first metal pad 41.

[0127] In addition, the first metal film 58 extends from the left to the right in the figure on the upper surface of the substrate 11 across the center line CL1 and along the inner edge of the bonding frame pattern 29. Moreover, the extension portion of the first metal film 58 is arranged in a manner that is separated from the first metal pad 41 and the second metal pad 42 and surrounds the first metal pad 41 and the second metal pad 42 from above in the figure.

[0128] The second metal film 59 is formed on the upper surface of the substrate 11 in a region below the center line CL2, covers the second metal wiring 56, and extends to a region outside the second metal wiring 56. In other words, the second metal film 59 covers the second metal wiring 56 except for the connection portion with the eighth metal pad 48.

[0129] In addition, the second metal film 59 extends from the right to the left in the figure on the upper surface of the substrate 11, crossing the center line CL1 and extending along the inner edge of the bonding frame pattern 29. Moreover, the extension portion of the second metal film 59 is separated from the seventh metal pad 47 and the eighth metal pad 48 and is arranged in a manner to surround the seventh metal pad 47 and the eighth metal pad 48 from below in the figure.

[0130] The first metal film 58 and the second metal film 59 are disposed on the substrate 11 away from the bonding frame pattern 29. In this embodiment, the first metal film 58 and the second metal film 59 are point-symmetrical about the intersection of the center line CL1 and the center line CL2 on the substrate 11.

[0131] The first separation film 61 is a covering film made of metal, and covers the first extension portion 29E1 of the joining frame pattern 29 in a manner that spans the first extension portion 29E1 of the joining frame pattern 29 in the vertical direction in the figure. The first separation film 61 is formed between the first metal film 58 and the second metal film 59 on the substrate 11, and is separated from the first metal film 58 and the second metal film 59.

[0132] The first separation film 61 is separated from the fourth metal pad 44, and extends from the area above the center line CL2 on the substrate 11 along the shape of the fourth metal pad 44, crossing the center line CL2 and covering the first extension portion 29E1 of the bonding frame pattern 29. In other words, the first separation film 61 separates the fourth metal pad 44 from the bonding frame pattern 29 when viewed from above.

[0133] The second separation film 62 is a covering film made of metal, and covers the second extension portion 29E2 of the joining frame pattern 29 in a manner that spans the second extension portion 29E2 of the joining frame pattern 29 in the up-down direction in the figure. The second separation film 62 is formed between the first metal film 58 and the second metal film 59 on the substrate 11, and is separated from the first metal film 58 and the second metal film 59.

[0134] The second separation film 62 is separated from the fifth metal pad 45, and extends from the area below the center line CL2 on the substrate 11 along the shape of the fifth metal pad 45, crossing the center line CL2 and covering the second extension portion 29E2 of the bonding frame pattern 29. In other words, the second separation film 62 separates the fifth metal pad 45 from the bonding frame pattern 29 when viewed from above.

[0135] In this embodiment, the first separation film 61 and the second separation film 62 are formed in an L shape on the substrate 11. The first separation film 61 and the second separation film 62 are point-symmetrical about the intersection of the center line CL1 and the center line CL2 on the substrate 11.

[0136] The first metal film 58 and the second metal film 59 covering the first metal wiring 55 and the second metal wiring 56, respectively, are matched with the first separation film 61 and the second separation film 62 in a manner that they are separated from each other and face each other, thereby forming a frame-shaped metal film surrounding the first metal pad 41 to the eighth metal pad 48. In other words, the light emitting elements 13A to 13D are surrounded by the first metal film 58, the second metal film 59, the first separation film 61, and the second separation film 62 in a frame shape when viewed from above.

[0137] As described above, in this embodiment, the first metal wiring 55 is connected to the first metal pad 41, the second metal pad 42 is connected to the third metal pad 43 via the first intermediate wiring 51, the fourth metal pad 44 is connected to the fifth metal pad 45 via the first extension portion 29E1 and the second extension portion 29E2 of the bonding frame pattern 29, the sixth metal pad 46 is connected to the seventh metal pad 47 via the second intermediate wiring 52, and the eighth metal pad 48 is connected to the second metal wiring 56.

[0138] That is, the light emitting element 13A bonded to the first metal pad 41 and the second metal pad 42, the light emitting element 13B bonded to the third metal pad 43 and the fourth metal pad 44, the light emitting element 13C bonded to the fifth metal pad 45 and the sixth metal pad 46, and the light emitting element 13D bonded to the seventh metal pad 47 and the eighth metal pad 48 are connected in series via the first intermediate wiring 51, the second intermediate wiring 52, and the bonding frame pattern 29 having the first extension portion 29E1 and the second extension portion 29E2.

[0139] As in Example 1, the first metal wiring 55 and the second metal wiring 56 are electrically connected to the first lower surface electrode 31 and the second lower surface electrode 32 provided on the lower surface of the substrate 11 via conductive holes (not shown) formed of a conductive metal that penetrate the substrate 11 in the up-down direction.

[0140] In this embodiment, the first metal wiring 55 can function as an anode, and the second metal wiring 56 can function as a cathode. Therefore, by energizing the first lower surface electrode 31 and the second lower surface electrode 32, current sequentially flows through the light emitting elements 13A, 13B, 13C, and 13D respectively bonded to the first metal pad 41 to the eighth metal pad 48, and the light emitting elements 13A to D respectively emit light.

[0141] As described above, in this embodiment, the bonding frame pattern 29 including the first extension portion 29E1 and the second extension portion 29E2 can function as a metal pattern for bonding the sealing cap 17 and also function as a metal wiring for electrically connecting the light emitting elements 13A to 13D.

[0142] In Example 2, first intermediate wiring 51 , second intermediate wiring 52 , third intermediate wiring 53 , fourth intermediate wiring 54 , first metal wiring 55 , and second metal wiring 56 are respectively formed by stacking Cu, Ni, Pd, and Au in this order on substrate 11 similarly to Example 1.

[0143] In addition, the first metal film 58 , the second metal film 59 , the first separator film 61 , and the second separator film 62 are stacked in the order of Ti and Al as in the first embodiment, and have a thin and dense aluminum oxide film, that is, a passivation film, all over the surface.

[0144] In the light emitting device 20 of the present embodiment, the first metal film 58 and the second metal film 59 respectively cover the first metal wiring 55 and the second metal wiring 56, similarly to the first embodiment. Therefore, in the bonding process (the above-mentioned crimping and melting process) of the sealing cover 17 when manufacturing the light emitting device 20, the first metal film 58 and the second metal film 59 repel the sealing bonding member 35 that melts and overflows.

[0145] Therefore, it is possible to prevent the melted and overflowed sealing bonding component 35 from wetting, spreading, fusing and solidifying on the surfaces of the first metal wiring 55 and the second metal wiring 56. Thus, the melted sealing bonding component 35 can be used to prevent the first metal wiring 55 and the second metal wiring 56 from being connected to the metal pad not connected to the metal wiring and causing a short circuit.

[0146] In addition, the first metal film 58 and the second metal film 59 respectively cover the first metal wiring 55 and the second metal wiring 56 as in the first embodiment, and extend to the area on the substrate 11 outside the first metal wiring 55 and the second metal wiring 56, and are arranged near the bonding frame pattern 29. Thus, the passive coating of the metal film can repel and push back the melted and overflowing sealing bonding member 35. In other words, it is possible to prevent the sealing bonding member 35 required for bonding the sealing cover 17 to the substrate 11 from being insufficient.

[0147] In addition, the first metal film 58 and the second metal film 59 can prevent the melted and overflowed sealing bonding component 35 from wetting, spreading, fusing and solidifying on the surfaces of the first metal pad 41 and the second metal pad 42 , the seventh metal pad 47 and the eighth metal pad 48 .

[0148] Furthermore, when manufacturing the light emitting device 20, when the light emitting elements 13B and 13C are respectively bonded to the upper surfaces of the fourth metal pad 44 and the fifth metal pad 45, the first separation film 61 and the second separation film 62 can repel and push back the bonding components of the light emitting elements. That is, the first separation film 61 and the second separation film 62 can prevent the bonding components of the light emitting elements 13B and 13C from wetting and spreading to the bonding frame pattern 29 when the light emitting elements 13B and 13C are bonded.

[0149] Furthermore, in the light-emitting device 20 of the present embodiment, the first separation film 61 and the second separation film 62 repel the melted and overflowed sealing bonding component 35, thereby the sealing bonding component 35 wets and spreads on the surface of the fourth metal pad 44 and the fifth metal pad 45, thereby preventing the installed (bonded) light-emitting elements 13B and 13C from being short-circuited.

[0150] Therefore, in the light emitting device 20 of the present embodiment, it is possible to prevent the above-mentioned short circuits between the metal wirings and metal pads, the poor airtightness caused by the lack of the bonding component at the bonding portion between the substrate 11 and the sealing cover 17, and the short circuit of the light emitting elements 13A to D. That is, in the light emitting device 20 of the present embodiment, it is possible to prevent defects from occurring during the manufacture of the light emitting device 20.

[0151] In the above-mentioned first and second embodiments, the substrate 11 is described as being in the form of a flat plate, but any structure may be used as long as the first metal film (26, 58) and the second metal film (27, 59) can cover the first metal wiring (23, 55) and the second metal wiring (24, 56), respectively. The substrate 11 may be formed of, for example, a ceramic substrate having a recess, and the bonding surface of the power supply wiring pattern and the sealing cover may not be on the same plane.

[0152] The size, shape or structure of each part in the light emitting device of the present invention is not limited to the above-mentioned embodiment and can be appropriately changed according to the application and the like.

Claims

1. A light emitting device, characterized in that: The light emitting device comprises: A substrate having a power supply wiring pattern and a bonding frame pattern, wherein the power supply wiring pattern includes: a first metal pad formed in a region on a surface of the substrate; a second metal pad formed in the region and separated from the first metal pad; a first metal wiring extending from the first metal pad to the outside of the region on the surface; and a second metal wiring extending from the second metal pad to the outside of the region and separated from the first metal pad and the first metal wiring, wherein the bonding frame pattern is a frame-shaped metal pattern separated from the power supply wiring pattern and surrounding the power supply wiring pattern; a light emitting element mounted on the one region of the surface of the substrate via the first metal pad and the second metal pad; and A sealing component having a frame-shaped sealing bonding component made of a metal material formed on the bottom surface, the sealing bonding component is opposite to the bonding frame pattern, the sealing bonding component and the bonding frame pattern are pressed and melted to bond the sealing bonding component to the substrate, and the sealing component seals the power supply wiring pattern and the light-emitting element. On the surface of the substrate, at least a portion of the surface of either the first metal wiring or the second metal wiring is covered by a covering film, which is separated from the bonding frame pattern and is composed of a metal material having a surface that has poor wettability to the material of the sealing bonding component compared to the upper surface of the first metal wiring and the second metal wiring.

2. The light emitting device according to claim 1, characterized in that: The first metal wiring is an anode wiring, the second metal wiring is a cathode wiring, and the first metal wiring is covered by the cover film.

3. The light emitting device according to claim 1 or 2, characterized in that: The first metal wiring extends over a first portion of a frame-shaped area surrounding the one area, and the second metal wiring extends over a second portion, which is the remaining portion other than the first portion in the frame-shaped area, and at least a portion of the surface of each of the first metal wiring and the second metal wiring is covered by the covering film.

4. The light emitting device according to claim 1 or 2, characterized in that: The cover film extends from the upper surfaces of the first metal wiring and the second metal wiring to the upper surface of the substrate through a surface facing the bonding frame pattern, and is separated from the bonding frame pattern.

5. The light emitting device according to claim 1 or 2, characterized in that: The sealing member includes a light-transmitting portion and a frame-shaped frame body portion. The light-transmitting portion is provided inside the frame body portion and can transmit light emitted from the light-emitting element.

6. The light emitting device according to claim 1 or 2, characterized in that: The capping film is composed of Al.

7. The light emitting device according to claim 1 or 2, characterized in that: A passivation film is formed over the surface of the cover film.

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