SEMICONDUCTOR LIGHT-EMITTING DEVICE

• US 20140014980A1
• Filed: 07/12/2013
• Published: 01/16/2014
• Est. Priority Date: 07/12/2012
• Status: Active Grant

• Current Assignee: Stanley Electric Company Limited
• Original Assignee: Stanley Electric Company Limited
• Inventors: Morimoto, Mayo
• Granted Patent: US 8,860,047 B2
• Time in Patent Office: Days
• US Class Current: 257/88
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 33/501 characterised by the materials, e.g. binder
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/52 Encapsulations
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin

Abstract

A reliable semiconductor light-emitting device can include a wavelength converting material in a cavity mounting at least one semiconductor light-emitting chip. The device can also include an encapsulating resin to cover the wavelength converting material so as to emit a wavelength-converted light using light emitted from the chip. The wavelength converting material should include a transparent resin having a large thermal expansion coefficient to maintain a high thermal resistance, and the encapsulating resin is subject to cracks due to a high transparent resin. The semiconductor device can be configured to form a space between the wavelength converting material and the encapsulating resin so that each of the encapsulating resin and the wavelength converting material cannot contact with each other even under a high temperature. Thus, the disclosed subject matter cannot stress in the encapsulating resin when the wavelength converting material expands, and therefore can provide the reliable semiconductor light-emitting device.

Claims

1. A semiconductor light-emitting device including an optical axis comprising:

a base board including a first board and a second board having a top surface, and being formed in a substantially rectangular tabular shape, the first board having a top surface and a through hole, including a first conductor pattern having an inner top edge adjacent the through hole, and the first board including at least one first bonding conductor pattern formed on the top surface of the first board, the base board attaching the first board on the top surface of second board, and thereby the through hole of the first board being configured to form a cavity along with a part of the top surface of the second board in the base board, the cavity of the base board being provided with a bottom surface of the cavity by using the part of the top surface of the second board exposed from the first board, and the cavity including a center on the bottom surface of the cavity, and the base board further including at least one second bonding conductor pattern formed on at least one of the top surface of the first board and the top surface of the second hoard, wherein the optical axis of the semiconductor light-emitting device intersects with the center on the bottom surface of the cavity at a substantially right angle;

at least one semiconductor light-emitting chip having a top surface, a bottom surface, a first electrode formed on the top surface and a second electrode, and mounted substantially on the bottom surface of the cavity, the top surface of the semiconductor light-emitting chip including a center on the top surface, and the first electrode of the semiconductor light-emitting chip being electrically connected to the first bonding conductor pattern via a first bonding wire;

a wavelength converting material having a top surface made by mixing at least a phosphor with a first transparent resin having a thermal expansion coefficient, encapsulating the at least one semiconductor light-emitting chip and a part of the first bonding wire in the cavity, and the top surface of the wavelength converting material banking from the inner top edge of the first conductor pattern of the first board toward the first bonding wire; and

an encapsulating resin being composed of a second transparent resin having a thermal expansion coefficient, encapsulating another part of the first bonding wire, which is not encapsulated by the wavelength converting material, and covering the wavelength converting material, wherein the encapsulating resin and the wavelength converting material contacts with each other substantially between the part and the other part of the first bonding wire, and therefore the semiconductor light-emitting device is configured to form a space between the encapsulating resin and the top surface of the wavelength converting material at least by using said bank from the inner top edge of the first conductor pattern of the first board toward the first bonding wire.

2. The semiconductor light-emitting device according to claim 1, wherein the at least one second bonding conductor pattern is formed on at least the bottom surface of the cavity, which is provided by using the part of the top surface of the second board exposed from the first board, and the second electrode of the semiconductor light-emitting chip is formed on the bottom surface of the semiconductor light-emitting chip, and therefore is electrically connected to the second bonding conductor pattern.

3. The semiconductor light-emitting device according to claim 1, wherein the first electrode of the semiconductor light-emitting chip is formed substantially at the center of the top surface of the semiconductor light-emitting chip.

4. The semiconductor light-emitting device according to claim 1, wherein the bottom surface of the cavity is formed in a substantially planar shape and also is formed in a substantially circular shape in a top view from the optical axis of the semiconductor light-emitting device.

5. The semiconductor light-emitting device according to claim 1, wherein the thermal expansion coefficient of the first transparent resin included in the wavelength converting material is larger than that of the second transparent resin of the encapsulating resin.

6. The semiconductor light-emitting device according to claim 1, wherein the first transparent resin of the wavelength converting material includes a silicone resin and the second transparent resin of the encapsulating resin includes an epoxy resin.

7. The semiconductor light-emitting device according to claim 1, wherein when the at least one semiconductor light-emitting chip is a plurality of semiconductor light-emitting chips, each of first electrodes of the at least one semiconductor light-emitting chip is located substantially on at least one of the optical axis of the semiconductor light-emitting device and an imaginary circle in which the optical axis of the semiconductor light-emitting device is central to the imaginary circle, and when the at least one semiconductor light-emitting chip is a single semiconductor light-emitting chip, the first electrodes of the at least one semiconductor light-emitting chip is located substantially on the optical axis of the semiconductor light-emitting device.

8. The semiconductor light-emitting device according to claim 2, wherein when the at least one semiconductor light-emitting chip is a plurality of semiconductor light-emitting chips, each of first electrodes of the at least one semiconductor light-emitting chip is located substantially on at least one of the optical axis of the semiconductor light-emitting device and an imaginary circle in which the optical axis of the semiconductor light-emitting device is central to the imaginary circle, and when the at least one semiconductor light-emitting chip is a single semiconductor light-emitting chip, the first electrodes of the at least one semiconductor light-emitting chip is located substantially on the optical axis of the semiconductor light-emitting device.

9. The semiconductor light-emitting device according to claim 1, wherein the top surface of the wavelength converting material is formed in a substantially concave shape in a direction toward the at least one semiconductor light-emitting chip between the inner top edge of the first conductor pattern of the first board and the first bonding wire.

10. The semiconductor light-emitting device according to claim 2, wherein the top surface of the wavelength converting material is formed in a substantially concave shape in a direction toward the at least one semiconductor light-emitting chip between the inner top edge of the first conductor pattern of the first board and the first bonding wire.

11. The semiconductor light-emitting device according to claim 1, wherein the at least one second bonding conductor pattern is formed on the top surface of the first board in the base board, which is located opposite the at least one first bonding conductor pattern, the second electrode of the semiconductor light-emitting chip is formed on the top surface of the semiconductor light-emitting chip along with the first electrode thereof and is electrically connected to the second bonding conductor pattern via a second bonding wire, the wavelength converting material also encapsulates a part of the second bonding wire in the cavity and the top surface of the wavelength converting material also banks from the inner top edge of the first conductor pattern of the first board toward the second bonding wire, and the encapsulating resin also encapsulates another part of the second bonding wire, which is not encapsulated by the wavelength converting material, and covering the wavelength converting material, wherein the encapsulating resin and the wavelength converting material contacts with each other substantially between the part and the other part of the second bonding wire, and therefore the semiconductor light-emitting device is configured to form a space between the encapsulating resin and the top surface of the wavelength converting material at least further by using said bank from the inner top edge of the first conductor pattern of the first board toward the second bonding wire.

12. The semiconductor light-emitting device according to claim 11, further comprising:

a second conductor pattern is formed on at least the bottom surface of the cavity, which is provided by using the part of the top surface of the second board exposed from the first board, and the second conductor pattern is located between the bottom surface of cavity and the bottom surface of the at least one semiconductor light-emitting chip.

13. The semiconductor light-emitting device according to claim 11, wherein each of the first electrode and the second electrode formed on the top surface of the semiconductor light-emitting chip is located substantially on an imaginary circle, in which the optical axis of the semiconductor light-emitting device is central to the imaginary circle.

14. The semiconductor light-emitting device according to claim 11, wherein the bottom surface of the cavity is formed in a substantially planar shape and also is formed in a substantially circular shape in a top view from the optical axis of the semiconductor light-emitting device.

15. The semiconductor light-emitting device according to claim 11, wherein the thermal expansion coefficient of the first transparent resin included in the wavelength converting material is larger than that of the second transparent resin of the encapsulating resin.

16. The semiconductor light-emitting device according to claim 11, wherein the first transparent resin of the wavelength converting material includes a silicone resin and the second transparent resin of the encapsulating resin includes an epoxy resin.

17. The semiconductor light-emitting device according to claim 11, wherein when the at least one semiconductor light-emitting chip is a plurality of semiconductor light-emitting chips, a respective one of first electrodes and second electrodes of the at least one semiconductor light-emitting chip is located substantially on at least one imaginary circle in which the optical axis of the semiconductor light-emitting device is central to the imaginary circle, and when the at least one semiconductor light-emitting chip is a single semiconductor light-emitting chip, each of the first electrode and the second electrode of the at least one semiconductor light-emitting chip is located substantially on one imaginary circle in which the optical axis of the semiconductor light-emitting device is central to the imaginary circle.

18. The semiconductor light-emitting device according to claim 12, wherein when the at least one semiconductor light-emitting chip is a plurality of semiconductor light-emitting chips, a respective one of first electrodes and second electrodes of the at least one semiconductor light-emitting chip is located substantially on at least one imaginary circle in which the optical axis of the semiconductor light-emitting device is central to the imaginary circle, and when the at least one semiconductor light-emitting chip is a single semiconductor light-emitting chip, each of the first electrode and the second electrode of the at least one semiconductor light-emitting chip is located substantially on one imaginary circle in which the optical axis of the semiconductor light-emitting device is central to the imaginary circle.

19. The semiconductor light-emitting device according to claim 11, wherein the top surface of the wavelength converting material is formed in a substantially concave shape in a direction toward the at least one semiconductor light-emitting chip between the inner top edge of the first conductor pattern of the first board and the second bonding wire.

20. The semiconductor light-emitting device according to claim 12, wherein the top surface of the wavelength converting material is formed in a substantially concave shape in a direction toward the at least one semiconductor light-emitting chip between the inner top edge of the first conductor pattern of the first board and the second bonding wire.