JP7523345B2 - Semiconductor device and its manufacturing method - Google Patents

Description

The present invention relates to a semiconductor device that encapsulates a semiconductor light-emitting element inside and a method for manufacturing the same.

Conventionally, semiconductor devices in which a semiconductor element is sealed inside a package are known. In the case of a semiconductor light-emitting module, a cap having a transparent window member that transmits light emitted from the light-emitting element is joined to a support on which the light-emitting element is mounted, and the cap is hermetically sealed.

For example, in the semiconductor module of Patent Document 1, a light-emitting element that emits ultraviolet light is housed in a recess in a substrate, and the opening of the recess is covered by a window member. The semiconductor module is sealed via a metal layer provided on both the main surface and the side surface of the window member.

Since the metal layer is provided on both the incident surface and the side surface, the sealing portion is bonded to both the incident surface and the side surface via the metal layer. This improves the bond with the sealing portion compared to when the metal layer is provided on only one of the incident surface and the side surface. Since the metal layer is provided so as to cover the corner formed by the incident surface and the side surface, a certain bond strength can be maintained against stress applied to the corner of the window member.

In addition, the sealing portion forms a fillet whose thickness decreases from the top surface toward the periphery of the top surface from the side surface due to the surface tension between the metal layer and the metal surface in a molten state. By providing such a fillet, a certain bonding strength can be maintained against the stress applied to the window member due to the difference in thermal expansion coefficient between the substrate and the window member (see Patent Document 1, paragraphs 0017, 0027, and 0029, and Figure 1).

JP 2015-18873 A

However, the semiconductor module of Patent Document 1 had a problem in that if there was a misalignment in the bonding of the window member to the substrate, there would be an excess or shortage of bonding material, and a fillet would not be formed on the side of the window member, reducing the bonding strength.

The present invention was made in consideration of these circumstances, and aims to provide a semiconductor device with a simple structure and stable bonding strength, and a method for manufacturing the same.

The semiconductor device of the present invention comprises a light-emitting element that emits light, a substrate on which the light-emitting element is mounted, and a sealing cap that is bonded to the substrate and encloses the light-emitting element inside. The sealing cap comprises a light-transmitting window that transmits light from the light-emitting element and an annular metal frame that surrounds the light-transmitting window. The substrate has an annular metal ring at a position opposite to the bottom end face of the metal frame, and the bottom end face of the metal frame and the metal ring are sealed with a bonding member. An annular repelling film having a metal oxide film or a passivation film is provided on at least the top and side surfaces of the metal ring inside the bottom end face of the metal frame.

The present invention is a semiconductor device that is formed by bonding a substrate on which a light-emitting element is mounted to a sealing cap, and light emitted from the light-emitting element is emitted to the outside through a light-transmitting window in the sealing cap.

During bonding, a bonding member is placed between the bottom end face of the metal frame and the metal ring of the substrate, and both are hermetically sealed. A repelling film is provided on the top and side surfaces of the metal ring that are inside the metal frame. This repelling film has a metal oxide film or a passivation film, and its surface is smooth and repels the molten bonding member. Therefore, even if the molten bonding member protrudes from the bonding area, it returns to its original position, and even if the sealing cap is misaligned, the formation area of the bonding member is restricted. As a result, the semiconductor device of the present invention has a simple structure and stable bonding strength.

In the semiconductor device of the present invention, it is preferable that the outer peripheral edge of the repelling film extends to the position of the bottom end surface of the metal frame.

By extending the outer edge of the repelling membrane to the bottom end of the metal frame, the joining material that protrudes inward from the metal frame during joining is repelled and returned to the bottom end. This prevents the joining material from breaking into small pieces.

In addition, in the semiconductor device of the present invention, the repelling film is preferably made of aluminum (Al), chromium (Cr), titanium (Ti), nickel (Ni), molybdenum (Mo) or tungsten (W).

For example, if aluminum (Al) is used as the material for the repelling film, it can repel the joining member reliably. In addition, such materials have a high affinity with the substrate and can also reflect light from the light-emitting element.

In addition, in the semiconductor device of the present invention, it is preferable that the bottom end surface of the metal frame has an inner chamfered portion in which the corners connected to the inner surface of the metal frame are chamfered.

The bottom end surface of the metal frame has an inner chamfered portion, so that if the sealing cap is misaligned, the inner chamfered portion functions as a reservoir for the joining material. This makes it possible to prevent the joining material from protruding inward from the metal frame.

In addition, in the semiconductor device of the present invention, it is preferable that the outer peripheral end of the repelling film extends to a position that reaches within the inner chamfered portion of the metal frame.

With this configuration, the joining material that protrudes inward during joining is repelled by the repelling membrane and returned to the inside chamfer of the metal frame. This makes it possible to prevent the joining material from breaking into small pieces.

In addition, in the semiconductor device of the present invention, it is preferable that the width (w) by which the outer peripheral end of the repelling film penetrates into the inner surface of the metal frame is 1/4 or less of the maximum width (h) of the metal frame.

By making the insertion width (w) of the repelling film 1/4 or less of the maximum width (h) of the metal frame, a certain level of bonding strength can be ensured for the bond between the substrate and the sealing cap.

In addition, in the semiconductor device of the present invention, it is preferable that the bottom end surface of the metal frame has an outer chamfered portion in which the corners connected to the outer surface of the metal frame are chamfered.

With this configuration, the bonding material that protrudes outward during bonding forms a fillet, but some of the bonding material is retained within the outer chamfer. This increases the bonding strength between the substrate and the sealing cap.

Another invention is a manufacturing method for a semiconductor device that includes a substrate on which a light-emitting element is mounted, a sealing cap that includes a transparent window that transmits light from the light-emitting element, and a ring-shaped metal frame that surrounds the transparent window, and includes the steps of: providing a ring-shaped metal ring at a position on the substrate that faces the bottom end face of the metal frame; forming a ring-shaped repelling film having a metal oxide film or a passivation film on the top surface and inner side of the metal ring that are inside the bottom end face of the metal frame when the sealing cap is mounted on the substrate; and joining the metal frame and the metal ring with a joining member, and sealing the light-emitting element in a closed space formed by the substrate and the sealing cap.

In the manufacturing method of the present invention, a circular metal ring is provided on the substrate at a position facing the bottom end surface of the metal frame of the sealing cap. Next, a repelling film is provided on the top and side surfaces of the metal ring that are located inside the metal frame.

Then, the bottom end surface of the metal frame and the metal ring of the substrate are joined and sealed with a joining material. The repelling film has a metal oxide film or a passivation film, and its surface is smooth and repels the molten joining material. Therefore, even if the molten joining material protrudes from the joining area, it returns to its original position, and even if the sealing cap is misaligned, the formation area of the joining material is restricted. As a result, the manufacturing method of the present invention can manufacture a semiconductor device with a simple structure and stable joining strength.

1 is a plan view showing a schematic top surface of a semiconductor light emitting module according to an embodiment of the present invention; FIG. 2 is a cross-sectional view of the semiconductor light emitting module taken along line AA in FIG. FIG. 2 is a plan view illustrating a schematic top surface of a substrate. 3B is a cross-sectional view of the substrate taken along line BB in FIG. 3A. FIG. 1 is an enlarged cross-sectional view of a semiconductor light-emitting module (misalignment of a sealing cap). 13 is an enlarged cross-sectional view of a semiconductor light emitting module (modified form). 13 is an enlarged cross-sectional view of a semiconductor light emitting module (modified form, misalignment of the sealing cap); 4 is a flowchart showing a method for manufacturing the semiconductor light emitting module of the present invention.

In the following, preferred embodiments of the present invention will be described, which may be modified and combined as appropriate. In the following description and accompanying drawings, substantially the same or equivalent parts are designated by the same reference numerals.
[Structure of Semiconductor Device]

Figure 1 is a plan view showing a schematic top surface of a semiconductor light-emitting module 10 according to an embodiment of the semiconductor device of the present invention. Also, Figure 2 is a plan view showing a schematic cross section of the semiconductor light-emitting module 10 taken along line A-A in Figure 1.

The semiconductor light-emitting module 10 mainly consists of a substrate 11 and a sealing cap 19, in which a light-emitting diode 15 is sealed. The sealing cap 19 also includes a metal frame 12 and a light-transmitting window 13.

The substrate 11 is a ceramic substrate made of aluminum nitride (AlN), which is impermeable to gases and the like. A first mounting electrode (cathode) 14A and a second mounting electrode (anode) 14B, which are wiring electrodes within the semiconductor light-emitting module 10, are provided on the substrate 11. A light-emitting diode (LED) 15, which is a semiconductor light-emitting element, is mounted on the first mounting electrode 14A and the second mounting electrode 14B (hereinafter referred to as mounting electrode 14 unless otherwise specified), and the light-emitting diode 15 is electrically connected to these electrodes.

In addition, a Zener diode (ZD) 16, which is a protective element connected to the first mounting electrode 14A and the second mounting electrode 14B, is provided on the substrate 11 to prevent electrostatic damage to the light-emitting diode 15.

The light emitting diode 15 is, for example, an aluminum nitride LED element (UV-LED element) that emits ultraviolet light with a wavelength of 250 to 270 nm. The light emitting diode 15 has a cathode electrode and an anode electrode on the back surface, and is flip-chip bonded to the first mounted electrode 14A and the second mounted electrode 14B of the substrate 11, respectively. The aluminum (Al) composition of the semiconductor crystal that constitutes the UV-LED element is high, and is easily oxidized and deteriorated by moisture ( _H2O ).

The metal frame 12 of the sealing cap 19 is hermetically joined to the substrate 11 by a metal ring 21 provided on the substrate 11 and a bonding layer or bonding material 22 such as gold-tin (Au-Sn). If a flux made of oil or organic acid is used as the bonding material 22, it will be carbonized by the light with a wavelength of 250 to 400 nm emitted from the UV-LED element, reducing the light emission output. For this reason, a material that does not contain flux or organic acid is used as the bonding material 22.

By joining the metal frame 12 to the metal ring 21, the sealing cap 19 and the substrate 11 define a closed space, and the light emitting diode 15, the first mounted electrode 14A, and the second mounted electrode 14B are hermetically sealed inside the closed space. The interior of the semiconductor light emitting module 10 is filled with nitrogen gas (N ₂ ) as a filling gas. In addition to nitrogen gas, an inert gas such as argon (Ar) or helium (He) may be filled. Furthermore, 5 to 20 vol % oxygen (O ₂ ) gas may be added to the filling gas.

The first mounted electrode 14A, the second mounted electrode 14B, and the metal ring 21 are made of a thick copper (Cu) film and a nickel/palladium/gold (Ni/Pd/Au) film formed on the Cu film. The description "material a/material b/material c" indicates a laminate in which material a, material b, and material c are laminated in the listed order. That is, in the above example, Ni, Pd, and Au are laminated in that order on the Cu film.

The metal frame 12 is made of a Ni-Co-Fe low thermal expansion metal such as Kovar (registered trademark), and its surface is coated with a nickel/gold (Ni/Au) film.

The light-transmitting window 13 is made of silicate glass, borosilicate glass, quartz glass, or the like that transmits the light emitted from the light-emitting diode 15, and has a convex (spherical) surface. The light-transmitting window 13 is hermetically joined to the metal frame 12. In the following, an example will be described in which the light-transmitting window 13 is a glass window made of silicate glass.

In the semiconductor light-emitting module 10 of this embodiment, a ductile metal frame 12 is disposed between the glass window (light-transmitting window 13), which is a hard and brittle ceramic, and the substrate 11, and the difference in linear thermal expansion coefficients of the members to be joined together is within 1 (×10 ⁻⁶ ·K ⁻¹ ), thereby making it possible to reduce stress applied to the joint due to heat generation due to current flow and fluctuations in the atmospheric temperature, etc. The thermal expansion coefficients (α) of the various members are as follows:
Light-transmitting window 13: silicate glass: α=5.8 (×10 ⁻⁶ ·K ⁻¹ )
・Metal frame 12; Ni-Co-Fe metal: α=5.1 (×10 ⁻⁶・K ⁻¹ )
Substrate 11: AlN: α=4.5 (×10 ⁻⁶ ·K ⁻¹ )

Figure 3A is a plan view that shows a schematic top surface of substrate 11, and Figure 3B is a cross-sectional view that shows a schematic cross-section of substrate 11 taken along line B-B in Figure 3A.

As shown in FIG. 3A, a rectangular, annular metal ring 21 is provided on the outer periphery of the upper surface of the substrate 11. In addition, a rectangular, annular repelling film 23 made of a thin metal film is provided on the inner peripheral region of the metal ring 21, on the inner peripheral side surface, and in the portion extending from the inner peripheral side surface to the upper surface of the substrate 11.

In this embodiment, the repelling film 23 is composed of chromium (Cr) and a chromium alloy having a chromium oxide passivation film on its surface. The repelling film 23 may be composed of any metal or alloy whose surface forms a passivation film made of a metal oxide film, for example, metals such as aluminum (Al), titanium (Ti), nickel (Ni), molybdenum (Mo), tungsten (W), etc., and alloys containing at least one of these metals. In particular, the passivation film of chromium (Cr) is preferable because it is not removed even by the strong oxide film remover (also called an activator) used when joining the light-emitting diode 15 to the mounting electrode 14.

Aluminum (Al) is also a preferred material for the repelling film 23. Aluminum (Al) has a high affinity with the aluminum nitride (AlN) substrate 11, and high adhesion can be obtained when the repelling film 23 is extended onto the upper surface of the substrate 11. Aluminum (Al) also has a high reflectance (e.g., 70% or more) in a wide wavelength range from ultraviolet to infrared (wavelengths of 200 to 2000 nm), and can therefore improve the light output of the semiconductor light-emitting module 10.

As shown in FIG. 3B, the upper surface of region 21A (the peripheral region of metal ring 21) of metal ring 21 on the outer periphery side of repelling membrane 23 is a bonding region with metal frame 12. In addition, first mounting electrode 17A and second mounting electrode 17B (hereinafter, referred to as mounting electrodes 17 unless otherwise specified) are provided on the rear surface of substrate 11.

The first mounting electrode 17A and the second mounting electrode 17B are made of a thick copper (Cu) film and a nickel/gold (Ni/Au) film formed on the Cu film. The first mounting electrode 17A and the second mounting electrode 17B are electrically connected to the first mounting electrode 14A and the second mounting electrode 14B, respectively, by metal vias 18 made of copper (Cu).

Next, the cross section of the semiconductor light emitting module 10 will be described in detail with reference to Figures 4 and 5.

Figure 4 shows a cross section of the sealing cap 19 when it is sealed in the correct position relative to the substrate 11. At this time, the two are joined by the joining member 22 with the center of the bottom end face of the metal frame 12 and the center of the metal ring 21 coinciding (the position where the margin created when the outline of the bottom end face of the metal frame 12 overlaps the outline of the metal ring 21 when viewed from above is equal around the entire circumference).

On the inside of the metal frame 12, the repelling film 23 covers the upper and inner surfaces of the metal ring 21 and extends to a position that reaches the upper surface of the substrate 11. As a result, when the substrate 11 and the sealing cap 19 are joined, the repelling film 23 repels the melted and protruding joining member 22, returning the joining member 22 to between the metal ring 21 and the metal frame 12.

As a result, as shown in the figure, a fillet 22f is formed by the joining member 22 on the outside of the metal frame 12, improving the joining strength between the substrate 11 (metal ring 21) and the sealing cap 19 (metal frame 12).

In addition, the repelling film 23 covers the inner surface of the metal ring 21 and the upper surface of the substrate 11, preventing a portion (tip) of the molten and protruding joining material 22 from adhering to the side wall of the metal ring 21 and remaining there to become metal fragments. As a result, there is no shortage of the joining material 22 required to join the substrate 11 and the sealing cap 19, and a fillet 22f is formed at the joining portion of the metal ring 21 and the metal frame 12.

The outer peripheral edge of the repelling film 23 can also be extended beyond the upper surface intersection position (the inner edge of the bottom end surface of the metal frame 12) of the metal ring body 21, which extends and intersects with the inner surface of the metal frame 12, and to a position equivalent to the thickness of the joining member 22. This makes it possible to prevent the molten joining member 22 from protruding.

As a result, the bonding member 22 can be held in the outer region of the repelling film 23, enabling a highly reliable bond without a shortage of bonding member 22 when bonding the sealing cap 19 and the substrate 11. In addition, a fillet 22f is formed that faces the outer surface of the metal frame 12 of the sealing cap 19 and the outer peripheral upper surface of the metal ring body 21 of the substrate 11, enabling a strong bond.

In addition to the above-mentioned repelling film 23, an independent repelling film (repelling film 24 in the figure) can be provided to cover the outer peripheral region and outer peripheral side surface of each of the first mounted electrode 14A and the second mounted electrode 14B individually. The provided repelling film 24 can repel and return the molten joining material 22 that reaches the upper side of the first mounted electrode 14A and the second mounted electrode 14B, making it possible to achieve a highly reliable joining without a shortage of joining material 22. It can also prevent short circuits of the mounted electrode 14.

Figure 5 shows a cross section of the sealing cap 19 sealed at an offset position relative to the substrate 11.

Here, the center of the bottom end face of the metal frame 12 and the center of the metal ring 21 do not coincide with each other, and the two are joined via the joining member 22. Even in this case, the repelling film 23, which covers the upper and side surfaces of the metal ring 21 and extends to a position reaching the upper surface of the substrate 11, repels the joining member 22 when the substrate 11 and the sealing cap 19 are joined.

On the left side of FIG. 5, the repelling film 23 prevents the joining member 22 from infiltrating inward toward the bottom end face of the metal frame 12. On the right side of FIG. 5, the repelling film 23 prevents the joining member 22 from protruding inward toward the bottom end face of the metal frame 12. As a result, a fillet 22f is formed on the outside of the metal frame 12 on the left side, and a fillet 22g is formed on the inside of the metal frame 12 on the right side.

In this way, even if the sealing cap 19 rubs against the substrate 11, the bonding member 22 is held in the outer region of the repelling film 23. This allows for a highly reliable bond between the sealing cap 19 and the substrate 11 without a shortage of bonding member 22. In addition, fillets 22f, 22g are formed on the inner and outer surfaces of the metal frame 12 of the sealing cap 19 and on the inner and outer upper surfaces of the metal ring 21 of the substrate 11, allowing for a strong bond.

Next, a detailed cross-section of the semiconductor light-emitting module 10 according to the modified embodiment will be described with reference to Figures 6 and 7.

Figure 6 shows a cross section of the sealing cap 20 when it is sealed in the correct position relative to the substrate 11. At this time, the two are joined via the joining member 22 with the center of the bottom end face of the metal frame 12 and the center of the metal ring 21 coinciding (the position where the margin created when the outline of the bottom end face of the metal frame 12 overlaps the outline of the metal ring 21 when viewed from above is equal all around).

As shown in the figure, the bottom end surface of the metal frame 12 in the modified embodiment has an inner chamfered portion 12a in which the corners connecting to the inner surface are chamfered, and an outer chamfered portion 12b in which the corners connecting to the outer surface are chamfered. The repelling film 25 covers the upper and side surfaces of the metal ring 21 and extends to a position that reaches the upper surface of the substrate 11. Furthermore, the outer peripheral end of the repelling film 25 extends into the inner surface of the metal frame 12 by the insertion width (w).

The joining member 22 fills the gap between the bottom end face of the metal frame 12 and the metal ring 21, and also fills the outer periphery of the metal ring 21 and the outer chamfered portion 12b, forming a fillet 22f. This improves the joining strength between the substrate 11 (metal ring 21) and the sealing cap 19 (metal frame 12). In particular, because the outer periphery of the repelling film 25 is structured to extend into the inner surface of the metal frame 12 by the insertion width (w), even if the inner chamfered portion 12a is provided, it repels the molten joining member 22, making it possible to form a fillet 22f that faces the outer chamfered portion 12b of the metal frame 12 and the outer periphery of the metal ring 21.

The penetration width (w) of the repelling film 25 is preferably equal to or greater than the distance from the inner surface of the metal frame 12 to the junction of the inner chamfer 12a and the bottom end surface, and equal to or less than 1/4 of the maximum width (h) of the metal frame 12. This condition prevents the joining member 22 from creeping up onto the inner chamfer 12a, and facilitates the formation of a fillet 22f that faces the outer chamfer 12b and the outer peripheral upper surface of the metal ring 21. This ensures a certain level of joining strength between the substrate 11 and the sealing cap 20.

As a result, the joining member 22 can be held in the outer region of the repelling film 25. Therefore, when joining the sealing cap 20 and the substrate 11, a fillet 22f is formed that faces the outer chamfered portion 12b of the metal frame 12 and the outer peripheral upper surface of the metal ring body 21 of the substrate 11, making it possible to join with high strength.

Figure 7 shows a cross section of the sealing cap 20 sealed at a misaligned position relative to the substrate 11. At this time, the center of the bottom end face of the metal frame 12 and the center of the metal ring 21 do not coincide with each other, and the two are joined via the joining member 22.

On the left side of FIG. 7, the repelling film 25 prevents the joining member 22 from infiltrating inward toward the bottom end face of the metal frame 12. On the right side of FIG. 7, the repelling film 25 prevents the joining member 22 from protruding inward toward the bottom end face of the metal frame 12.

Therefore, on the left side, a fillet 22f is formed on the outside of the metal frame 12, and on the right side, a fillet 22g is formed between the inner chamfer 12a of the metal frame 12 and the top surface of the metal ring 21, and a fillet 22f is formed between the outer chamfer 12b and the top surface of the metal ring 21.

The chamfered portion of the bottom end surface of the metal frame 12 may be a C-chamfer (machined at about 45°) or an R-chamfer with a specified curvature. In addition, the size of the inner chamfered portion 12a and the outer chamfered portion 12b is preferably such that the lateral stress applied from any direction to the sealing cap 20 acts as a compressive stress on the fillet, so it is preferable that the outer chamfered portion 12b is large.

The combined width of the inner chamfer 12a and the outer chamfer 12b is preferably 1/2 or less of the width (thickness) of the metal frame 12. By making the width of the bottom end face of the metal frame 12 1/2 or more of the width (thickness) of the metal frame 12, the vertical bonding strength of the sealing cap 20 can be maintained at a certain level or higher.

In this way, even if the sealing cap 20 is misaligned with respect to the substrate 11, the joining member 22 is held in the outer region of the repelling film 25. As a result, when joining the sealing cap 20 and the substrate 11, a fillet 22f is formed that faces the outer chamfered portion 12b of the metal frame 12 and the outer circumferential upper surface of the metal ring body 21 of the substrate 11, making it possible to achieve a high-strength joining.
[Manufacturing process of semiconductor light emitting module 10]

The semiconductor light emitting module 10 of this embodiment is manufactured by the method described in the flowchart of FIG.

First, the component preparation process is carried out (STEP 01). First, the metal frame 12 and silicate glass chip are set in the lower press mold, and the upper press is lowered to weld the silicate glass chip to the metal frame 12 and form the light-transmitting window 13. Next, Ni (1.5 to 5.0 μm)/Au (0.3 μm or more) plating is applied to the parts of the metal frame 12 where the light-transmitting window 13 is not welded. After that, a flux-free joining member 22 (Au-Sn annular ribbon) is temporarily attached to the bottom end surface of the metal frame 12, and sealing caps 19, 20 are formed.

To form the substrate 11, via holes for electrode connection are opened in an aluminum nitride (AlN) substrate (thickness 0.38 mm), and copper (Cu) is applied to the front and back of the AlN substrate and the inner surface of the via hole by electroless plating. Then, a thick film of Cu with a thickness of 50 μm or more is formed on the Cu surface by electrolytic plating. At this time, a metal via 18 is formed with Cu filled inside the via hole. Next, a Ni (4.5±1.5 μm)/Pd (0.05 μm or more)/Au (0.05 μm or more) layer is formed on the top surface of the Cu by EB (electron beam) evaporation or resistance heating, etc.

Then, the metal is removed by photolithography from areas other than the areas where the electrodes and metal rings are to be formed, forming the electrodes 14, 17 and the metal rings 21. This results in the formation of the metal rings 21 and the electrodes 14, 17 that are fixed to the substrate (i.e., have sealing properties).

Then, the resist is patterned, chromium (Cr) is deposited by EB deposition or the like, and the resist is removed by lift-off to form a patterned chromium (Cr) layer that will become the repellent film 23 on the metal ring 21. The patterned chromium (Cr) layer is then exposed to clean air with a humidity of 70% or less for 3 hours to form the repellent film 23 with a passive chromium oxide film on its surface.

Next, the element bonding process is performed (STEP 02). Specifically, the light emitting diode 15 and the Zener diode 16 are mounted (bonded) onto the mounting electrodes 14A and 14B by Au-Sn eutectic bonding (fluxless) using thermal welding. At this time, formic acid can be used as a bonding aid. Note that when mounting elements by reflow using an Au-Sn paste containing a bonding aid such as flux and organic acid, the flux can be removed by cleaning after mounting.

Here, the chromium (Cr) passivation film cannot be removed with any bonding aid other than a strong acid such as phosphoric acid. Also, the aluminum (Al) passivation film cannot be removed with a weak acid such as formic acid. Therefore, the bonding aid used in the element bonding process can be selected according to the metal that will become the repelling film 23.

If the light-emitting diode 15 or the Zener diode 16 is of the vertical conduction type, a wire bonding process is performed (STEP 03). The light-emitting diode 15 and the Zener diode 16 are connected by wire bonding to the electrode pads of each element and to either the mounting electrodes 14A or 14B. Note that this embodiment uses a flip chip (a type of chip with electrically paired electrode pads on one side for bonding), so this process is omitted.

Finally, the sealing process is performed (STEP 04). Specifically, the substrate 11 on which the light-emitting diode 15 and Zener diode 16 are mounted is set in a thermal welding eutectic device. The sealing cap 19 is then grasped with a tool and aligned with the substrate 11. The sealing cap 19 is then pressed against the substrate 11 (approximately 100 gf) and simultaneously heated to 300°C to bond the metal ring 21 of the substrate 11 to the metal frame 12 by thermal welding eutectic bonding. This results in an airtight bond (seal) between the sealing cap 19 and the substrate 11.

By the above process, even if the molten joining material (e.g., Au-Sn) tries to protrude inside the semiconductor light emitting module 10 during joining, the molten joining material is repelled by the repelling film 23 on the metal ring body 21, preventing it from protruding into the inside of the module. In addition, by selecting a joining assistant, the passive film formed on the repelling film 23 is removed, preventing the joining material 22 from protruding into the inside of the module.

10 Semiconductor light emitting module 11 Substrate 12 Metal frame 12a Inner chamfered portion 12b Outer chamfered portion 13 Light-transmitting window 14 Mounting electrode 14A First mounting electrode 14B Second mounting electrode 15 Light emitting diode 16 Zener diode 17 Mounting electrode 17A First mounting electrode 17B Second mounting electrode 18 Metal vias 19, 20 Sealing cap 21 Metal ring body 22 Bonding members 23, 24, 25 Repelling membrane

Claims (8)

A light emitting element that emits light;
A substrate on which the light emitting element is mounted;
a sealing cap bonded to the substrate and enclosing the light emitting element therein;
the sealing cap includes a light-transmitting window through which light from the light-emitting element passes, and an annular metal frame surrounding the light-transmitting window;
the substrate has an annular metal ring at a position opposite to a bottom end surface of the metal frame,
a bottom end surface of the metal frame and the metal ring are sealed with a joining member;
A semiconductor device, comprising: an annular repelling film having a metal oxide film or a passivation film provided on at least an upper surface and side surfaces of the metal ring body on the inside of a bottom end surface of the metal frame body. The outer peripheral end of the repelling membrane extends to the bottom end surface of the metal frame.
2. The semiconductor device according to claim 1, wherein the semiconductor device comprises: The repelling film is made of aluminum (Al), chromium (Cr), titanium (Ti), nickel (Ni), molybdenum (Mo) or tungsten (W).
3. The semiconductor device according to claim 1, wherein the first and second electrodes are electrically connected to each other. The bottom end surface of the metal frame has an inner chamfered portion in which a corner connected to the inner surface is chamfered.
4. The semiconductor device according to claim 1, wherein the first insulating layer is a first insulating layer. The outer circumferential end of the repelling film extends to a position that reaches inside the inner chamfered portion of the metal frame.
5. The semiconductor device according to claim 4. The width (w) of the outer circumferential edge of the repelling membrane entering from the inner surface of the metal frame is ¼ or less of the maximum width (h) of the metal frame.
6. The semiconductor device according to claim 5, The bottom end surface of the metal frame has an outer chamfered portion in which a corner connected to the outer surface is chamfered.
7. The semiconductor device according to claim 1, wherein the first insulating layer is a conductive layer. 1. A method for manufacturing a semiconductor device including a substrate on which a light-emitting element is mounted, and a sealing cap including a light-transmitting window that transmits light from the light-emitting element and an annular metal frame that surrounds the light-transmitting window, comprising:
providing an annular metal ring on the substrate at a position opposite to a bottom end surface of the metal frame;
forming an annular repelling film having a metal oxide film or a passivation film on the upper surface and inner side surface of the metal ring body that are located inside the bottom end surface of the metal frame when the sealing cap is placed on the substrate;
a step of joining the metal frame and the metal ring with a joining member and sealing the light emitting element in a closed space formed by the substrate and the sealing cap;
A manufacturing method of a semiconductor device comprising:

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