CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority to Chinese Patent Application No. 202010722870.5, filed on Jul. 24, 2020, said application being incorporated by reference in its entirety herein.
FIELD OF THE INVENTION
This disclosure relates to an optoelectronic device, and in particular, to a light emitting diode lamp package having glue on two sides.
BACKGROUND
A light emitting diode is a solid-state optoelectronic device configured to transform electricity into luminous energy. The light emitting diode includes a semiconductor chip. A negative electrode of the chip is connected to a metal frame, the positive electrode of the chip is connected to a power supply pin, and the chip is completely wrapped by epoxy resins. The LED chip includes a P-type semiconductor and an N-type semiconductor. When current is applied to the chip via bonding wires, the chip illuminates. The LED chip requires protection from dust and dirt, humidity, electrostatic discharge (ESD) and mechanical disruption. When applying current, heat generated in the P-N semiconductors has to be removed to prevent the light emitting diode from being overheated. In the art various materials and package structures are developed to remove heat generated by the light emitting diode.
FIG. 1, FIG. 2, and FIG. 3 show a light emitting diode package 1 known in the art, in which FIG. 1 is a front view, FIG. 2 is a top view, and FIG. 3 is a bottom view. As shown in the drawings, the light emitting diode package includes a printed circuit board 2, an LED chip 3, a first bonding wire 4, a second bonding wire 5, and a transparent glue bulk 6. A chip bonding pad 2c and a wire bonding pad 2d are disposed on a top surface of the printed circuit board 2, and two mounting pads 2e are disposed on a bottom surface of the printed circuit board 2. The LED chip 3 is mounted on the chip bonding pad 2c. The first bonding wire 4 and the second bonding wire 5 respectively connect two electrodes of the LED chip to the chip bonding pad 2c and the wire bonding pad 2d. The transparent glue bulk 6, of epoxy resins or silicon, is molded to wrap the LED chip 3, the first bonding wire 4 and the second bonding wire 5, so as to protect the light emitting diode 3.
FIG. 4, FIG. 5, and FIG. 6 show the light emitting diode package 1 soldered onto two metal wires 200. The metal wire 200 can be a bare wire, or the exposed part of an enameled wire or a plastic coated wire. The two metal wires 200 are respectively soldered to the two mounting pads 2e. Through the first bonding wire 4, the second bonding wire 5, the chip bonding pad 2c, and the wire bonding pad 2d, electricity is provided to the LED chip 3 and the LED chip 3 illuminates. Usually the metal wire 200 is a copper wire, and wires made of the other metal having high conductivity are adoptable. However, shielded by the printed circuit board 2, the field angle of the light emitting diode package 1 cannot be larger than 180 degrees.
In addition, when soldering the light emitting diode package 1 onto the metal wires 200, solder paste is put onto the metal wire 200 first, and then the two mounting pads 2e are put onto the two metal wires 200. Next, the light emitting diode package and the metal wires 200 are moved to a reflow oven for reflow soldering. In the reflow soldering process, tin solder has good liquidity at high temperature. The light emitting diode package 1 might drift along with the flowing tin; as a result, soldering failure occurs. The soldering failure may cause an open-circuit, short-circuit, or an oblique mechanical arrangement of components. Rework is required for soldering failures and increases manufacturing costs including increasing labor costs and material costs.
SUMMARY
In view of the above problem, this disclosure provides a light emitting diode package (LED lamp) having glue on two sides to solve the problems in the art.
This disclosure provides a light emitting diode package having glue on two sides including a metal frame, an LED chip and a transparent glue bulk. The metal frame includes a top surface and a bottom surface, and the metal frame further includes a first mounting pad and second mounting pad. A light transmission gap is defined between the first mounting pad and the second mounting pad. The light transmission gap provides communication of the top surface and the bottom surface, and causes the first mounting pad and the second mounting pad to be spaced apart from each other. The LED chip is mounted on the first mounting pad corresponding to the top surface. A first electrode and a second electrode of the LED chip are electrically connected to the first mounting pad and the second mounting pad respectively. The transparent glue bulk covers the top (first) surface and the bottom (second surface), wraps around the LED chip, and fills the light transmission gap. Outer edges of the first mounting pad and the second mounting pad are exposed from the transparent glue bulk.
In at least one embodiment, the light emitting diode package having glue on two sides further includes a first bonding wire and a second bonding wire, wherein the first bonding wire is connected to the first electrode and the first mounting pad, and the second bonding wire is connected to the second electrode and the second mounting pad.
In at least one embodiment, the transparent glue bulk includes an upper molded glue bulk and a lower molded glue bulk respectively combined with the top surface and the bottom surface.
In at least one embodiment, the upper molded glue bulk and the lower molded glue bulk are combined with each other via the light transmission gap, and the upper molded glue bulk wraps the light emitting diode, the first bonding wire, and the second bonding wire.
In at least one embodiment, The light emitting diode package having glue on two sides further includes two metal wires; wherein portions, of the first mounting pad and the second mounting pad, exposed from the transparent glue bulk and corresponding the bottom surface are respectively soldered to the two metal wires.
In at least one embodiment, the lower molded glue bulk is located between the two metal wires.
In an embodiment of this disclosure, the transparent glue bulk is configured to limit the movement of the two metal wires. Namely, even if the metal wires drift due to the melted solder paste during reflow soldering, the two metal wires just clamp the transparent glue bulk, and connections between the metals wires and the mounting pads remain. Good soldering maintains product quality and production yield, and reduces manufacturing cost including labor cost and material cost.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given herein below for illustration only, and thus not limitative of the present invention, wherein:
FIG. 1 is a front view of a light emitting diode package known in the prior art;
FIG. 2 is a top view of a light emitting diode package, as known in the prior art;
FIG. 3 is a bottom view of a light emitting diode package, as known in the prior art;
FIG. 4 is a front view of a light emitting diode package soldered onto two metal wires, as known in the prior art;
FIG. 5 is a top view of a light emitting diode package soldered onto two metal wires, as known in the prior art;
FIG. 6 is a front view of a light emitting diode package welded onto two metal wires, as known in the prior art;
FIG. 7 is a front view of a light emitting diode package according to an embodiment of this disclosure;
FIG. 8 is a top view of a light emitting diode package according to an embodiment of this disclosure;
FIG. 9 is a bottom view of a light emitting diode package according to an embodiment of this disclosure;
FIG. 10 is a front view of a light emitting diode package soldered onto two metal wires according to an embodiment of this disclosure;
FIG. 11 is a top view of a light emitting diode package soldered onto two metal wires according to an embodiment of this disclosure; and
FIG. 12 is a bottom view of a light emitting diode package soldered onto two metal wires according to an embodiment of this disclosure.
DETAILED DESCRIPTION
Referring to FIG. 7, FIG. 8, and FIG. 9, a light emitting diode package 100, also referred to as an LED lamp or LED lamp package, having glue on two sides according to an embodiment of this disclosure is shown. The light emitting diode package having glue on two sides 100 includes a metal frame 110, an LED chip 120, a first bonding wire 131, a second bonding wire 132, and a transparent glue bulk or material 140.
As shown in FIG. 7, FIG. 8, and FIG. 9, the metal frame 110 is made of metal, and has good electrical and thermal conductivities. The metal 110 includes a top surface 113 and a bottom surface 114. The metal frame 110 further includes a light transmission gap G, and the light transmission gap G communicates between the top surface 113 and the bottom surface 114. In particular, in this embodiment, the metal 110 includes a first mounting pad 111 and a second mounting pad 112. The light transmission gap G is defined between the first mounting pad 111 and the second mounting pad 112. The light transmission gap G communicates the top surface 113 and the bottom surface 114, and keeps the first mounting pad 111 and the second mounting pad 112 being spaced from each other.
As shown in FIG. 7, FIG. 8, and FIG. 9, the first mounting pad 111 provides a bonding position, and the bonding position corresponds to the top surface 113. The LED chip 120 is disposed at the bonding position, that is, the LED chip 120 is mounted on the first mounting pad 111, and corresponds to the top surface 113 of the metal frame 110. The LED chip 120 includes a first electrode 121 and a second electrode 122. As shown in FIG. 7, FIG. 8, and FIG. 9, the first bonding wire 131 is connected to the first electrode 121 and the first mounting pad 122, and the second bonding wire 132 is connected to the second electrode 122 and the second mounting pad 112. The first bonding wire 131 and the second bonding wire 132 electrically connect the LED chip 120 to the first mounting pad 111 and the second mounting pad 112.
As shown in FIG. 7, FIG. 8, and FIG. 9, the transparent glue material 140 covers the top (first) surface 113 and the bottom (second) surface 114, wraps around the LED chip 120, the first bonding wire 131 and the second bonding wire 132, and fills the light transmission gap G. Moreover, outer edges of the first mounting pad 111 and the second mounting pad 112 are exposed from the transparent glue bulk 140; namely, the two opposite edges of the metal frame 110 are exposed from the transparent glue bulk 140.
As shown in FIG. 7, the transparent glue bulk 140 includes an upper molded glue material 141 and a lower molded glue material 142, respectively combined with the top surface 113 and the bottom surface 114. The upper molded glue material 141 and the lower molded glue material 142 fill the light transmission gap G and are combined with each other via the light transmission gap G. In one example, the lower molded glue bulk 142 is combined with the bottom surface 114 at first to bind the first mounting 111 and the second mounting pad 112 into the metal frame 110, and then the LED chip is mounted and the bonding wires 131, 132 are bonded. Finally the upper molded glue material 141 is combined with the top surface 113 to wrap around and cover the LED chip 120, the first bonding wire 131 and the second bonding wire 132.
Referring to FIG. 10, FIG. 11, and FIG. 12, the light emitting diode package having glue on two sides 100 is provided to be soldered onto two metal wires 200. The metal wire 200 can be a bare wire, or the exposed part of an enameled wire or a plastic coated wire. Portions, of the first mounting pad 111 and the second mounting pad 112, exposed from the transparent glue bulk on bottom surface are respectively welded to the two metal wires 200. Through the first bonding wire 131, the second bonding wire 132, the first mounting pad 111, and the second mounting pad 112, electricity is provided to the LED chip 120 and the LED chip 120 illuminates. Usually the metal wire 200 is a copper wire, and wires made of the other metal having high conductivity are adoptable. Providing a plurality of light emitting diode packages 100 welded onto the two metal wires 200 in sequence, a light string that illuminates light in plural directions is obtained.
As shown in FIG. 7 to FIG. 12, Applying electricity to the first electrode 121 and the second electrode 122 via the two metal wires 200, the LED chip 120 illuminates. At the moment, the transparent glue material 140 serves as a light-guide, and light diverges upward on the top surface 113. Meanwhile, the transparent glue material 140 guides light to travel through the light transmission gap G, and to travel through the lower molded glue material 142. And finally, the light diverges downward. Therefore, in this disclosure, the light emitting diode package having transparent glue on two sides 100 illuminates light in 360 degrees and metal frame 110 has good thermal conductivity to dissipate heat from the LED chip 120. In addition, by coating or electroplating a reflecting layer on the surface of the metal frame 110, light absorbed by the surface of the metal frame 110 is prevented and luminance upward or downward is enhanced. Particles, such as fluorescent particles, reflective particles, or dye particles, can be added into the transparent glue bulk 140 to change illumination characteristics.
As shown in FIG. 10, observing in the front view of the light emitting diode package having glue on two sides 100, outer edges of the first mounting pad 111 and the second mounting pad 112 are exposed from the lower molded glue material 142, and L-shaped sections are formed between the lower molded glue material 142 and the mounting pads 111, 112. The two metal wires 200 are located in the L-shaped sections respectively, and are respectively welded to the first mounting pad 111 and the second mounting pad 112. Therefore, the lower molded glue bulk 142 is located between the two metal wires 200. The transparent glue bulk 142 limits the movement of the two metal wires 200. In other words, in this embodiment, even if the metal wires 200 drift due to the melted solder paste in the reflow soldering, the two metal wires just clamp the lower molded glue material 142, and connections between the metals wires 200 and the mounting pads 141, 142 remain. Good soldering maintains product quality and production yield, and reduces manufacturing cost including labor cost and material cost.
Patent Application
20220029073
