A Lighting Device and an Encapsulation Method therefor Technical Field

The present invention relates to a lighting device. In addition, the present invention further relates to an encapsulation method for the lighting device.

Background Art The injection molding process is usually used for encapsulation of a lighting device when the lighting device for signage display is manufactured. Two holes should be provided on a printed circuit board in order to arrange the printed circuit board of the lighting device on a mold of an injection molding machine. During the encapsulation, two pins should be inserted respectively into the holes, and then, the printed circuit board with a light source is arranged, together with the pins, on the mold of the injection molding machine. The pins are removed from the lighting device after the lighting device is encapsulated with an encapsulation material. At this time, the holes, even a part of the printed circuit board, will be exposed on the lighting device after the encapsulation. This is quite bad for improving the IP protection level of the whole lighting device. Besides, the process of inserting the pins into the holes and arranging the lighting device to be encapsulated on the mold of the injection molding machine is quite tedious and time-consuming, because the mold is mounted in the injection molding machine, which is a very uncomfortable position for the operator. Summary of the Invention

In order to solve the above problem, the present invention provides a lighting device that has a high IP protection level, and the lighting device according to the present in- vention is more easily located on a mold during encapsulation, which makes the encapsulation become simple and easy. In addition, the present invention further relates to an encapsulation method for the lighting device above.

One object of the present invention is accomplished via a lighting device through the following solution. The lighting device comprises an encapsulation material and a lighting assembly encapsulated by the encapsulation material, wherein the lighting assembly comprises a printed circuit board, a light source mounted on one side of the printed circuit board and a positioning means mounted on the other side of the printed circuit board for positioning on a mold during encapsulation. In one solution of the present invention, the positioning means is also encapsulated by the encapsulation material after the lighting assembly is encapsulated by the en- capsulation material, and the positioning means will not be removed. Therefore, the lighting device is completely encapsulated by the encapsulation material, and no gap or hole that may expose the printed circuit board of the lighting assembly will appear, so that a good waterproof and dustproof function of the lighting device is assured with a high IP protection level .

According to one solution of the present invention, the positioning means has a fastening part on one side, and a mold positioning part on the other side. The printed circuit board can be fixed on the positioning means with the fastening part so that the printed circuit board is assured to be unchanged with respect to location of the positioning means during the encapsulation. In a preferred solution of the present invention, the fastening part is configured as a pin, and the printed circuit board is provided with a hole adapted to insertion of the pin thereinto. Such a simple structure makes sure that no relative displacement will occur between the printed circuit board and the positioning means.

Further preferably, the mold positioning part is a positioning recess adapted to insertion of a part of the mold thereinto. In a practical encapsulation, the mold can be easily inserted into the positioning recess so as to ensure that the positioning means fixed with the printed circuit board can be fixed in a predetermined location of the mold.

According to a preferred solution of the present invention, the positioning means further has a base that is provided with a pin on one side, and, a projection on the other side that defines the positioning recess with respect to the base. Such a positioning means forms an integral frame structure similar to an H shape, and such an integral frame structure is more advantageous for operation of an operator. Moreover, since the projection is provided, it is easier to align the mold with the positioning recess on the projection when the positioning means is arranged on the mold so that the positioning means can be easily and precisely arranged on the mold .

Preferably, the encapsulation material encapsulates all areas, with an exception of the positioning recess, on the other side of the base. In fact, the positioning means and the lighting assembly are completely encapsulated by the encapsulation material after the encapsulation is completed, and all possible gaps or holes are sealed since the position- ing means acts as one part of the encapsulation, which prominently improves the waterproof and dustproof performances of the lighting device.

Preferably, the positioning means is bonded or welded on the printed circuit board. By firmly connecting the printed cir- cuit board and the positioning means, the positioning means is preferably prevented from falling off from the printed circuit board when the lighting assembly is arranged in the mold .

According to the present invention, the positioning means is made from polycarbonate, polymethyl methacrylate or metal materials. Of course, the positioning means also can be made from other materials adapted to encapsulation.

According to a preferred solution of the present invention, at least one cooling fin is formed on one side of the posi- tioning means that has the mold positioning part. Since the positioning means is not removed after the encapsulation is completed, and the positioning means and the printed circuit board are fixedly connected together, it is quite favorable for dissipating heat of the printed circuit board by provid- ing the cooling fin on the positioning means for improving the thermal dissipating performance of the lighting device.

Preferably, the encapsulation material is thermoplastic poly- urethane elastomer, polyurethane or polyvinyl chloride. Of course, the encapsulation material also may be other materials adapted to encapsulation.

Advantageously, the lighting assembly is encapsulated by the encapsulation material through an over molding process or a low pressure molding process.

The other object of the present invention is accomplished via an encapsulation method for the lighting device above. The method comprises steps of a) providing a printed circuit board, wherein the printed circuit board is mounted with a light source on one side and a positioning means on the other side; b) positioning the positioning means with the printed circuit board in a mold; and c) encapsulating the printed circuit board and the positioning means by an encapsulation material. The positioning means is also encapsulated after a lighting device is encapsulated with this encapsulation method, and the positioning means will not be removed, thus, the lighting device is completely encapsulated by the encapsulation material and no gap or hole that may expose the printed circuit board of the lighting assembly will appear, so that a good waterproof and dustproof function of the lighting device is assured with a high IP protection level.

According to the present invention, in the step a) the positioning means is mounted on the other side of the printed circuit board by inserting a pin on the positioning means into a hole in the printed circuit board. Such a simple structure makes sure that no relative displacement will occur between the printed circuit board and the positioning means.

Further according to the present invention, in the step b) the positioning means is positioned in the mold with a positioning recess of the positioning means. In a practical encapsulation, the mold can be easily inserted into the positioning recess so as to ensure that the positioning means fixed with the printed circuit board can be fixed in a predetermined location of the mold.

Advantageously, in the step c) the printed circuit board and the positioning means are encapsulated through an over molding process or a low pressure molding process. Brief Description of the Drawings

The accompanying drawings constitute a part of the present Description and are used to provide further understanding of the present invention. Such accompanying drawings illustrate the embodiments of the present invention and are used to de- scribe the principles of the present invention together with the Description. In the accompanying drawings the same components are represented by the same reference numbers. As shown in the drawings :

Fig. 1 is a schematic diagram of a lighting device according to the present invention;

Fig. 2 is a schematic diagram of a lighting assembly of a lighting device that is mounted on a mold according to the present invention;

Fig. 3 is a schematic diagram of one side of a positioning means of a lighting device according to the present invention; Fig. 4 is a schematic diagram of the other side of the positioning means of the lighting device according to the present invention .

Detailed Description of the Embodiments Fig. 1 is a schematic diagram of a lighting device according to the present invention. As can be seen from the figure, the lighting device has a lighting assembly and an encapsulation material 1 encapsulating the lighting assembly. The lighting assembly comprises a printed circuit board 2 and a lighting source 3 mounted on one side of the printed circuit board 2. In one solution of the present invention, the lighting assembly is configured as an LED lighting assembly, and the light source 3 thus is an LED chip. A lens 10 is further provided on the LED chip for adjusting light emitted from the LED chip. Besides, the lighting assembly further has a positioning means 5 mounted on the other side of the printed circuit board 2 for location on a mold 4 (see Fig. 2) during encapsulation.

It can be seen from Fig. 1 that the positioning means 5 that is made from polycarbonate, polymethyl methacrylate or metal materials has a base 5a. A fastening part configured as a pin 6 is provided on one side of the base 5a facing the printed circuit board 2. Two holes 7 are provided on the printed circuit board 2, and the pin 6 is inserted into the hole 7 in an assembled state. After the assembling, the positioning means 5 is welded or bonded on the printed circuit board 2.

A mold positioning part which is a positioning recess 8 adapted to location on the mold 4 is provided on one side of the base 5a away from the printed circuit board 2. In one solution of the present invention, a projection 9 is formed on the one side of the base 5a away from the printed circuit board 2, and the projection 9 defines the positioning recess 8. The mold 4 is inserted into the positioning recess 8 when the lighting assembly is encapsulated, so as to locate the lighting assembly on the mold 4 (see Fig. 2) . The lighting assembly is encapsulated by the encapsulation material 1 af- ter it is arranged on the mold 4. As can be seen from the figure, the printed circuit board 2 and the positioning means 5 are encapsulated by the encapsulation material 1 and the lighting device of the present invention is formed after the mold 4 is removed. The over molding or low pressure molding process may be used for the encapsulation of the encapsulation material 1.

In a preferred solution of the present invention, a plurality of cooling fins (not shown in the figures) are also formed on one side of the base 5a where the projection 9 is provided. These cooling fins are favorable for improving the thermal dissipating performance of the lighting device.

Fig. 2 is a schematic diagram of the lighting assembly of the lighting device that is mounted on a mold according to the present invention. At this time, the mold 4 has been in- serted into the positioning recess 8, but the lighting assembly yet is not encapsulated by the encapsulation material 1.

Fig. 3 is a schematic diagram of one side of the positioning means 5 of the lighting device according to the present invention. As can be seen from the figure, two pins 6 are pro- vided on one side of the base 5a, and the projection 9 is formed on the other side of the base 5a.

Fig. 4 is a schematic diagram of the other side of the positioning means 5 of the lighting device according to the pre- sent invention. As can be seen from the figure, the projection 9 is formed on one side of the base 5a and defines the positioning recess 8 adapted to insertion of the mold 4 thereinto .

Next, an encapsulation method according to the present inven- tion will be described. In the method according to the present invention, firstly, a positioning means (5) is mounted on one side of a printed circuit board 2 that does not have a lighting source 3, wherein a pin 6 of the positioning means 5 is inserted into a hole 7 formed correspondingly in the printed circuit board 2, so as to position the printed circuit board 2 on the positioning means 5; then, the positioning means 5 with the printed circuit board 2 is arranged in a mold 4, wherein a corresponding positioning structure of the mold 4 is inserted into a positioning recess 8 of the posi- tioning means 5 for positioning the positioning means 5 with respect to the mold 4. After the positioning means 5 is arranged in the mold in a fixed location, the positioning means 5 and the printed circuit board 2 are encapsulated by an encapsulation material through an over molding process or a low pressure molding process. The positioning means 5 is maintained in the lighting device after the encapsulation and will not be removed for preventing exposure of the printed circuit board 2 when the positioning means is removed.

The above is merely preferred embodiments of the present in- vention but not to limit the present invention. For the person skilled in the art, the present invention may have various alterations and changes. Any alterations, equivalent substitutions, improvements, within the spirit and principle of the present invention, should be covered in the protection scope of the present invention.

List of reference signs encapsulation material printed circuit board light source (LED chip mold

positioning means base

pin

hole

positioning recess proj ection

lens