TWI640715B - Lighting module - Google Patents

Abstract

A light source module includes a substrate, a first light emitting diode chip, and a wavelength conversion layer. The first light emitting diode wafer is positioned on the substrate and has radiation at a wavelength of from 900 nm to 1000 nm; the wavelength conversion layer is positioned above the first light emitting diode wafer and is coupled to the first light emitting diode wafer The radiation undergoes wavelength conversion and produces radiation having a wavelength of less than 900 nm.

Description

Light source module

The present invention relates to semiconductor elements, and more particularly to a light source module using a light emitting diode as a light source.

The license plate recognition system is a common image recognition technology in the field of image processing. In order to improve the recognition effect, the light-emitting module and the light-receiving module required for capturing the license plate image in the license plate recognition system will adjust the applicable band according to the color of the license plate.

However, when the applicable wave segment of the license plate recognition system is in the red spectrum and the license plate recognition system is applied to the general road, the red light emitted by the license plate recognition system may cause the passerby to mistake the red identification of the license plate for the traffic sign. Red lights, which in turn affect road safety.

According to the present invention, a light source module includes a substrate, a first light emitting diode chip, and a wavelength conversion layer. The first light-emitting diode wafer is positioned on the substrate and has radiation at a wavelength of from 900 nm to 1000 nm; the wavelength conversion layer is positioned above the light-emitting diode wafer, and the wavelength conversion layer and the first light-emitting diode wafer are Part of the radiation undergoes wavelength conversion and produces radiation of wavelengths less than 900 nm.

In an embodiment of the present invention, the wavelength conversion layer may be positioned in an arc shape above the first light emitting diode wafer, and the wavelength conversion layer and the first light emitting diode wafer partially undergo wavelength conversion and may be generated. Visible light.

In another embodiment of the present invention, the light source module may further include a light transmissive colloid layer that may cover the first light emitting diode chip and the wavelength conversion layer in an arc shape.

In still another embodiment of the present invention, the light source module further includes a second LED chip positioned on the substrate and connected in series with the first LED chip, and the wavelength conversion layer can be simultaneously coated A second light emitting diode wafer. The second light emitting diode wafer may have a radiation having a wavelength of from 660 nm to 900 nm.

According to the present invention, a light source module includes a substrate, a plurality of first light emitting diode chips, a second light emitting diode chip, and a wavelength conversion layer. The first light emitting diode wafer is positioned on the substrate, and the first light emitting diode wafer has radiation having a wavelength of from 900 nm to 1000 nm. The second light emitting diode wafer is positioned on the substrate and has a radiation wavelength of 660 nm to 900 nm; the wavelength conversion layer covers the first light emitting diode chip and the second light emitting diode chip, and the wavelength conversion layer A portion of the radiation of the first light-emitting diode wafer undergoes wavelength conversion and produces radiation having a wavelength of less than 900 nanometers, and the first light-emitting diode wafer surrounds the second light-emitting diode wafer at equal intervals.

In an embodiment of the present invention, the first light emitting diode chips may be connected in parallel, and the second light emitting diodes may be connected in series with the first light emitting diode chips connected in parallel. Furthermore, the wavelength conversion layer and the partial emission of the first light-emitting diode wafer undergo wavelength conversion and can generate visible light.

In another embodiment of the present invention, the light source module further includes a circuit layer and a plurality of wires, the circuit layer is disposed on the substrate, and the wire is connected to the circuit layer, the first LED chip, and the second LED Between the body wafers, the first light emitting diode chip and the second light emitting diode chip are electrically connected. More specifically, the first light emitting diode chip may be a vertical structure type wafer, the second light emitting diode chip may be a horizontal structure type wafer; the first light emitting diode chip is positioned at a positive electrode in the circuit layer, and The lower electrode of the first light-emitting diode wafer is physically and electrically connected to the positive electrode; the wire is connected between the upper electrode of the first light-emitting diode wafer and the first electrode of the second light-emitting diode chip, Connecting between at least a second electrode of the second LED chip and a negative electrode in the circuit layer.

1, 3‧‧‧ light source module

10, 30‧‧‧ substrate

11a‧‧‧ positive electrode

11b‧‧‧Negative electrode

12, 32‧‧‧ first light-emitting diode chip

120‧‧‧Upper electrode

122‧‧‧ lower electrode

14‧‧‧Second light-emitting diode chip

140‧‧‧First electrode

142‧‧‧second electrode

16, 36‧‧‧ wavelength conversion layer

160, 360‧‧‧Fluorescent powder

18, 19‧‧‧ wires

31‧‧‧ circuit layer

320‧‧‧ electrodes

38‧‧‧Translucent colloid layer

1 is a plan view of a light source module according to a first embodiment of the present invention; FIG. 2 is a side view of a light source module according to a first embodiment of the present invention; A circuit diagram of a module; and FIG. 4 illustrates a side view of a light source module in accordance with a second embodiment of the present invention.

Please refer to FIG. 1 and FIG. 2 , which are respectively a top view and a side view of a light source module according to a first embodiment of the present invention. In FIG. 1, the light source module 1 includes a substrate 10, at least one first LED wafer 12, a second LED wafer 14, and a wavelength conversion layer 16; wherein, the first LED wafer 12 The number may be one or more, and in the present embodiment, the second LED wafer 12 is exemplified by two.

The first LED chip 12 and the second LED chip 14 are respectively positioned on the substrate 10, and the power required for operation is intercepted through the substrate 10; the wavelength conversion layer 16 covers at least the first LED chip 12, And performing wavelength conversion with a portion of the radiation of the first LED chip 12 to generate wavelength-converted radiation, and the wavelength of the wavelength-converted radiation is smaller than the wavelength of the radiation of the first LED wafer 12.

In FIG. 1 and FIG. 2, the substrate 10 has a flat shape, which can be made of a polymer material, ceramic or other insulating material; of course, the substrate 10 can also be made of a metal material whose outer layer is covered with an insulating layer, thereby achieving Improve the heat dissipation effect of the light source module 1. A circuit layer composed of a positive electrode 11a and a negative electrode 11b is attached to the surface of the substrate 10.

The first light-emitting diode wafer 12 has radiation at a wavelength of from 900 nm to 1000 nm; in other words, the first light-emitting diode wafer 12 is used to generate infrared light. The first LED wafer 12 is positioned on the substrate 10 and electrically connected to the circuit layer on the substrate 10. In FIG. 1, the first LED wafer 12 is a vertical structure wafer; that is, the electrodes of the first LED wafer 12 (ie, the upper electrode 120 and the lower electrode 122) are arranged in the semiconductor layer thereof. Relative sides. When the crystal is fixed, the lower electrode 122 of the first LED wafer 12 can be directly disposed on the positive electrode 11a, and the solder can be used to electrically connect the first LED wafer 12 and the lower electrode 122.

The second LED wafer 14 has a radiation having a wavelength of from 660 nm to 900 nm; in other words, the second LED chip 14 is used to generate red light. The second LED wafer 14 is positioned on the substrate 10 and electrically connected to the circuit layer on the substrate 10 and the first LED array 12 . In FIG. 1, the second LED wafer 14 is a horizontal structure wafer; that is, the electrode of the second LED wafer 14 (ie, the first battery) The pole 140 and the second electrode 142) are both arranged on the upper surface of the semiconductor layer thereof; wherein the first electrode 140 is a positive end and the second electrode 142 is a negative end. When the die bonding is performed, the lower surface of the second LED chip 14 that is not provided with the first electrode 140 and the second electrode 142 is directly attached to the substrate 10; after that, the wire bonding process is used to make the circuit layer and the first light. The diode chip 12 and the second LED wafer 14 are electrically connected (described later).

In FIG. 1 , the light source module 1 is exemplified by two first light emitting diode chips 12 and one second light emitting diode chip 14 . The light emitting power of each first light emitting diode chip 12 can be It is designed to be smaller than the power of the second LED wafer 14 and the sum of the luminous powers of the first LED wafer 12 is substantially the same as the emission power of the second LED wafer 14. The second light-emitting diode wafer 14 is positioned at the center of the substrate 10, and the first light-emitting diode wafer 12 is arranged on opposite sides of the second light-emitting diode wafer 14; thereby, the light mixing uniformity can be effectively improved. It should be particularly noted that when the number of the first LED chips 12 is greater than two, the first LED chips 12 are arranged equiangularly at the center of the second LED wafer 14 in the second The periphery of the LED wafer 12, that is, the first LED wafer 12, surrounds the second LED wafer 12. The light color uniformity emitted by the light source module 1 can be improved by surrounding the plurality of first light emitting diode wafers 12 around the second light emitting diode wafer 14.

After the die bonding is completed, the first LED chips 12 are respectively positioned on the positive electrode 11a, and the lower electrode 122 of the first LED chip 12 can be physically connected and electrically connected to the positive electrode 11a through solder. connection. Thereafter, a wire bonding process is performed to cause the wires 18 to straddle the upper electrode 120 and the second LED chip 14 of the first LED wafer 12 . Between the first electrodes 140, and the wires 19 are spanned between the second electrode 142 and the negative electrode 11b of the second LED chip 14, and form a circuit structure as shown in FIG.

In FIG. 3, the two first LED chips 12 are connected in parallel, and the anodes thereof are connected to the positive terminal of the power source (not shown), and the cathodes thereof are connected to the anode of the second LED 14; The cathode of the second LED chip 12 is connected to the negative terminal of the power source (not shown), that is, the second LED chip 14 is connected in series with the plurality of first LED chips 12 connected in parallel.

The phosphor powder 160 in the wavelength conversion layer 16 undergoes wavelength conversion with the radiation of the first LED array 12 and produces visible light radiation having a wavelength of less than 900 nm.

More specifically, the phosphor powder 160 in the wavelength conversion layer 16 can absorb the infrared light emitted by the first LED chip 12 and convert the infrared light into visible light by using an up-conversion characteristic; The "upconversion" is also known as Anti-Stokes Shift. In short, the phosphor powder 160 in the wavelength conversion layer 16 absorbs relatively low energy radiation (e.g., the aforementioned infrared light) and emits relatively high energy radiation (e.g., green light).

Since the second LED wafer 14 provides red light that cannot be wavelength-converted with the phosphor powder 160 in the wavelength conversion layer 16, the green light emitted by the wavelength conversion layer 16 (i.e., the aforementioned wavelength-converted light) is effectively mixed. And the red light emitted by the second LED chip 14 can obtain orange light visible to the human eye.

Referring to FIG. 1 , the wavelength conversion layer 16 covers the first LED body 12 and the second LED chip 14 in an arc shape; thereby, the effect of expanding the light angle of the light source module 1 can be achieved; The wavelength conversion layer 16 can also effectively prevent the first light emitting diode The wafer 12 and the second LED wafer 14 are damaged by the impact of the foreign object, and the moisture or dust is prevented from adhering to the surface of the first LED chip 12 and the second LED wafer 14 to affect the luminous efficiency or Even damaged. However, in actual implementation, the wavelength conversion layer 16 may also only cover the first LED array 12 and undergo wavelength conversion with a portion of the radiation of the first LED wafer 12. Compared with the first light-emitting diode chip 12 and the second light-emitting diode wafer 14 simultaneously covering the wavelength conversion layer 16 , the wavelength conversion layer 16 can only effectively reduce the first light-emitting diode wafer 12 . The loss generated when the red light emitted from the second light-emitting diode wafer 12 is transmitted in the wavelength conversion layer 16.

The phosphor powder 160 in the wavelength conversion layer 16 can be combined with a synthetic resin (not otherwise labeled), such as an epoxy resin or a resin, followed by spotting or coating on the first LED wafer 12 and/or second. On the LED wafer 14, it is dried, solidified, hardened or cured (for example, UV curing or room temperature curing).

In addition, the light source module 1 may further comprise a light transmissive colloid layer made of a suitable polymer material such as polycarbonate or other optically transparent material, which is molded on the wavelength conversion layer 16 and has a refractive index designed. The light is easily escaping from the light source module 1.

The light source module 1 of the present invention can be applied to a license plate recognition system using red light as an identification light source, because the emission of the second light-emitting diode wafer 14 is red light, so that an accurate license plate identification result can be provided; The emission of the first LED wafer 12 in the light source module 1 and the emission of the phosphor powder 160 in the wavelength conversion layer 16 may be mixed with the emission of the second LED wafer 14 to produce a human eye visible orange light. Therefore, it is possible to avoid the problem that the passerby mistakenly recognizes the license plate recognition red light as the red light in the traffic sign.

Please refer to FIG. 4 , which illustrates a side view of a light source module according to a second embodiment of the present invention. In FIG. 4, the light source module 3 includes a substrate 30, a first LED array 32, a wavelength conversion layer 36, and a light transmissive layer 38. The first light emitting diode chip 32 has a radiation having a wavelength of about 900 nm to 1000 nm. The first LED chip 32 is positioned on the substrate 30 and electrically connected to the circuit layer 31 formed on the substrate 30.

In FIG. 3, the first light emitting diode chip 32 is a flip chip structure; that is, the positive and negative electrodes 320 of the first light emitting diode chip 32 are spaced apart from one side of the semiconductor layer thereof. , not both sides. When the die bonding is performed, the surface of the first LED chip 32 provided with the electrode 320 is directly attached to the circuit layer 31, and the solder may be electrically connected to the circuit layer 31. In other words, the electrode 320 of the first LED chip 32 is physically and electrically connected to the circuit layer 31.

The wavelength conversion layer 36 is disposed on the top of the first LED array 32 (ie, the surface of the first LED array 32 is not provided with the electrode 320), and the phosphor powder 360 in the wavelength conversion layer 36 is combined with the first illumination. The wavelength conversion of the light emitted by the diode wafer 32 produces radiation having a wavelength of less than 900 nanometers.

More specifically, the phosphor powder 360 in the wavelength conversion layer 36 can absorb the infrared light emitted by the first light-emitting diode wafer 32 and convert the infrared light into visible light by utilizing the characteristic of up-conversion. In short, the phosphor in the wavelength conversion layer 36 will absorb relatively low energy emissions (such as the aforementioned infrared rays) and emit relatively high energy emissions (e.g., green light).

The light transmissive colloid layer 38 is made of a light transmissive colloid layer made of a polymer material such as polycarbonate or other optically transparent material, which is shaped to cover the circuit layer 31, first The light-emitting diode chip 32 and the wavelength conversion layer 36 are appropriately designed such that light easily escapes from the light source module 3.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any person skilled in the art can make various changes and refinements without departing from the spirit and scope of the present creation. The scope is subject to the definition of the scope of the patent application.

Claims (12)

A light source module comprising: a substrate; a first light emitting diode wafer positioned on the substrate, the first light emitting diode wafer having a wavelength of from 900 nm to 1000 nm; and a wavelength conversion a layer is disposed above the first LED chip, and the wavelength conversion layer is positioned in an arc shape above the first LED wafer, wherein the wavelength conversion layer and the first LED chip Part of the radiation undergoes wavelength conversion and produces radiation of wavelengths less than 900 nm. The light source module of claim 1, wherein the wavelength conversion layer and a portion of the first LED chip are wavelength-converted and generate visible light. The light source module of claim 1, further comprising a transparent colloid layer covering the first LED chip and the wavelength conversion layer. The light source module of claim 3, wherein the light transmissive colloid layer covers the first light emitting diode chip and the wavelength conversion layer in an arc shape. The light source module of claim 1, further comprising a second light emitting diode chip positioned on the substrate and electrically connected to the first light emitting diode chip, the second light emitting diode The bulk wafer has a radiation having a wavelength of from 660 nm to 900 nm. The light source module of claim 5, wherein the wavelength conversion layer simultaneously covers the second LED chip. The light source module of claim 5, wherein the first light emitting diode chip and the second light emitting diode chip are electrically connected in series. A light source module includes: a substrate; a plurality of first light emitting diode chips positioned on the substrate, the first light emitting diode wafer having a radiation wavelength of from 900 nm to 1000 nm; and a second light emitting a diode chip positioned on the substrate, the second LED chip having a wavelength of 660 nm to 900 nm; and a wavelength conversion layer covering the first LED chip and The second light-emitting diode wafer, the wavelength conversion layer and a portion of the first light-emitting diode wafer are wavelength-converted and generate radiation having a wavelength of less than 900 nm, wherein the first light-emitting diode wafers The second LED chip is arranged at an equiangular angle around the periphery of the second LED chip. The light source module of claim 8, wherein the wavelength conversion layer and a portion of the first LED chip are wavelength-converted and generate visible light. The light source module of claim 8, wherein the first light emitting diode chips are connected in parallel, and the second light emitting diodes are connected in series with the first light emitting diode chips connected in parallel. The light source module of claim 8 or 10, further comprising: a circuit layer disposed on the substrate; and a plurality of wires connected across the circuit layer, the first light emitting diode chips And electrically connecting the first light-emitting diode wafer and the second light-emitting diode wafer to each other between the second light-emitting diode wafers. The light source module of claim 11, wherein each of the first light emitting diode chips is a vertical structure type wafer, and the second light emitting diode chip is a horizontal structure type wafer, each of the first light emitting diodes The body wafer is positioned on one of the positive electrodes of the circuit layer, and a lower electrode of each of the first light-emitting diode chips is physically and electrically connected to the positive electrode, and the wires are connected to the first light-emitting diodes Between an upper electrode of the bulk wafer and at least a first electrode of the second LED chip, and between at least a second electrode of the second LED chip and one of the negative electrodes of the circuit layer.