CN202423377U - Waterproof SMD LED - Google Patents

Abstract

The utility model discloses a waterproof SMD (Surface-mount Device) LED, which comprises a circuit substrate, an LED wafer and a waterproof adhesive layer, wherein the circuit substrate comprises a metal sheet and a support frame of a resin reflective cup, the metal sheet is welded on the circuit substrate via soldering tin, and packing adhesive is filled in the resin reflective cup; the LED wafer is fixedly arranged at the bottom of the resin reflective cup, and the positive and the negative poles of the LED wafer are electrically connected with the positive and the negative poles of the metal sheet via wires; the waterproof adhesive layer is coated on the external surface of the support frame. According to the utility model, after an LED is welded on the circuit substrate, the waterproof adhesive layer is coated on the surface of the LED, therefore, a waterproof effect of the LED is achieved, and the LED has the advantages of easiness in implement, low raw material cost, wide application range and good waterproof effect.

Description

A waterproof SMD LED

technical field

The utility model relates to an LED assembly structure, in particular to an LED with a waterproof patch assembly structure. the

Background technique

In recent years, SMD LED has become a development hotspot, which solves problems such as brightness, viewing angle, flatness, and consistency. It is very suitable for high-resolution indoor and outdoor full-color displays and outdoor building lighting. application. However, this SMD LED itself has the problems of poor waterproofness and low reliability, which seriously limits its outdoor application. the

The waterproof difficulty of SMD LED is mainly caused by two aspects:

One is the water seepage of the LED bracket. The water seepage of the LED bracket is caused by the material of the bracket and the contact surface between the material and the electrode pins. At present, the bracket of the SMD LED is obtained by pressing plastic and metal electrodes. The plastic material used is polyphthalamide (PPA for short), and the materials of the metal electrodes include copper and aluminum. Weaknesses of the bracket with this material structure in terms of waterproofing are: 1) PPA material is easy to absorb moisture, and the water absorption rate is about 6%; And the subsequent use of the LED becomes larger, so that impurities such as water vapor can invade. the

The second is the water seepage of the LED packaging adhesive layer. The packaging glue used in LED is mainly epoxy resin and silicone resin (polysiloxane resin). The thermal expansion coefficient of epoxy resin or silicone resin is different from that of the LED bracket. During use, thermal expansion and contraction will weaken the adhesion between the encapsulation gel and the bracket, and gaps will appear, causing water vapor to infiltrate. In addition, the silicone resin structure is relatively loose, and moisture can easily penetrate. the

Chinese application number CN201020505895.1 discloses a moisture-proof SMD light-emitting diode, which realizes waterproofing by designing waterproof grooves at the opening of the package cavity and the joints of pads and pins. Chinese application number 201110078466.X discloses a packaging structure and packaging method of a patch-type outdoor LED. A waterproof structure is designed at the junction of the metal sheet and the reflective cup to achieve waterproofing. The common point of these two existing patent applications is to design a waterproof structure on the LED bracket. The disadvantage of this is that the processing of the LED bracket will become complicated and the cost of the LED bracket will increase significantly. the

Utility model content

Aiming at the problems of poor waterproofness and high cost of waterproof structure existing in the current SMD LED, the utility model provides a SMD LED solution which coats the surface of the LED with waterproof glue, so that the LED has a good waterproof effect. the

The utility model adopts the following technical solutions to realize: a waterproof patch LED, which includes: a circuit substrate; a bracket including a metal sheet and a resin reflective cup, and the metal sheet includes a positive metal sheet and a negative electrode metal sheet and is welded to the circuit board by soldering tin respectively. On the substrate, the resin reflective cup is filled with encapsulant; the LED chip fixed at the bottom of the resin reflective cup and the positive and negative poles of the LED chip are electrically connected to the positive metal sheet and the negative metal sheet respectively through wires; Waterproof adhesive layer on the outside surface. the

Among them, the resin reflection cup is a PPA reflection cup. the

Wherein, the wires are gold wires, aluminum wires, copper wires or silver wires. the

Compared with the prior art, the utility model has the following beneficial effects:

In the utility model, after the LED is welded on the circuit substrate, a waterproof glue layer is coated on the surface of the LED to realize the waterproof effect of the LED. Compared with the existing waterproof patch LED, the utility model has the advantages of simple process and easy realization, low cost of raw materials, wide application range and good waterproof effect. the

Description of drawings

Fig. 1 is a structural schematic diagram of the waterproof patch LED of the present invention. the

Detailed ways

As shown in Figure 1, the utility model proposes a waterproof SMD LED, which SMD LED includes: a circuit substrate 1 of PCB or MCPCB; a support including a metal sheet 3 and a resin reflective cup 5, wherein the metal sheet 3 passes The solder 2 is welded on the circuit board 1, and the metal sheet 3 includes a positive electrode metal sheet and a negative electrode metal sheet with an interval; the resin reflective cup 5 is filled with packaging glue (or fluorescent glue) 6; fixedly arranged on the resin reflective cup 5 LED chips 7 at the bottom of the cup, and the positive and negative poles of the LED chip 7 are electrically connected to the positive metal sheet and the negative metal sheet of the lead wire 8 respectively; a waterproof adhesive layer 4 is provided on the outer surface of the support. the

In this embodiment, the resin reflection cup 5 may be a PPA (polyphthalamide, English name is Polyphthalamide, PPA for short) reflection cup. the

In this embodiment, the wires 8 may be metal wires such as gold wires, aluminum wires, copper wires or silver wires. the

The waterproof adhesive layer 4 is especially coated on the contact between the metal sheet 3 and the resin reflection cup 5 and the contact between the encapsulation glue 6 and the bracket, and is applied by brushing, spraying or vapor deposition to form a waterproof adhesive layer 4. The waterproof function of the adhesive layer 4 realizes the waterproof performance of the SMD LED. the

After the SMD LED is welded on the PCB or MCPCB circuit substrate to obtain the LED display module or LED lighting semi-finished product, select colorless and transparent polyacrylic resin, colorless and transparent polyacrylic resin that can dry naturally, and whose viscosity is not greater than 290cps at room temperature. One or more of acrylic resin, colorless and transparent epoxy resin, colorless and transparent silicone resin, colorless and transparent polyurethane resin, coated with a thickness of 0.01mm to 1mm by brushing, spraying or steaming To the surface of the LED, focus on coating the contact between the metal sheet 3 and the resin reflective cup 5 and the contact between the encapsulant 6 and the bracket, and then dry naturally to obtain a SMD LED with good waterproof performance. the

It has been proved by practice that the patch LED proposed by the utility model has good waterproof performance. the

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present utility model shall be included in this utility model. within the scope of protection of utility models. the

Claims (3)

1. the paster LED of a waterproof is characterized in that, said paster LED comprises: circuit substrate; The support that comprises sheet metal and resin reflector, sheet metal comprise cathode metal sheet and negative pole sheet metal and are welded on the circuit substrate through scolding tin respectively, be filled with packaging plastic in the resin reflector; The LED wafer and the both positive and negative polarity of LED wafer that are fixedly installed at the bottom of the resin reflector cup are electrically connected with cathode metal sheet and negative pole sheet metal through lead respectively; Coating is arranged on the Waterproof glue line of the outer surface of support.

2. according to the paster LED of the said a kind of waterproof of claim 1, it is characterized in that the resin reflector is the PPA reflector.

3. according to the paster LED of claim 1 or 2 said a kind of waterproof, it is characterized in that lead is gold thread, aluminum steel, copper cash or silver-colored line.

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