JPH0357615B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for encapsulating bare electronic components present in the form of continuous strips arranged in a linear direction, the bare electronic components being encapsulated using an extrusion head at least once. It is intended to provide a container with a defined shape obtained by extruding a seed plastic material parallel to said primary direction.

The invention can be advantageously used in the general field of encapsulation of bare electronic components, particularly in the general field of encapsulating light emitting diodes to obtain display elements.

A known method of manufacturing display elements consists of using individual cups, the interior of which replicates the external shape of the display element, and such cups thus serving as molds for the plastic material. Each cup is manually filled with a drop of diffused resin and then filled with clear resin. The light emitting diodes constituting the active part of the display element are pretreated with a polymeric resin and then arranged in a transparent resin inside the cup. These resins are then polymerized and the display element thus obtained is removed from the cup. However, this method has several drawbacks. In fact, the cup filling operation adds to the relatively high cost of the display element. Furthermore, the cup can only be used a limited number of times,
After that, they must intersect.

The object of the invention is to avoid the above-mentioned disadvantages, on the basis that this type of manufacturing process can be fully mechanized by mass production.

The encapsulation method of the present invention can be carried out on components having hard connecting leads extending in a secondary direction that is substantially perpendicular to the primary direction in which the bare electronic components are arranged; are successively encased and immobilized in at least one plastic material such that the encapsulation is confined to the parts excluding the connecting leads, and as a final operation the arrayed parts are encased and immobilized. , and is characterized in that the common parts of the plastic material extruded from the extrusion head, which are continuous strips, are cut in such a way that the bare electronic components with such containers are separated from each other.

The method of the invention therefore allows the encapsulation of bare electronic components to be carried out semi-automatically and very continuously, which results in a very substantial reduction in manufacturing costs. Other advantages of the invention are:
It is possible to obtain not only individually encapsulated bare electronic components, but also any number of bars of bare electronic components.

In a first example of the invention, a container of plastic material extruded from an extrusion head has a groove, which groove is continuously filled with polymeric filled resin at the outlet of the extrusion head, and then stripped. An electronic component is placed in the groove and then the polymerizable filler resin is polymerized such that the component is immobilized within the groove.

This particular example is particularly advantageous when producing display elements by encapsulating light-emitting diodes.

In order to avoid the formation of air bubbles and the generation of mechanical tensions, the bare electronic components are pretreated with a polymeric hardening resin before being placed in the groove, and the polymeric hardening resin is then polymerized.

In a second example of the invention, bare electronic components are
Continuously, by introducing said strip of said part directly into an extrusion head, into a container of plastic material having an extruded shape, and by encapsulating said part within the plastic material itself. Immobilize. This example is of particular interest because it significantly simplifies the operation of immobilizing bare electronic components. This example also has the advantage that the container can be of any desired shape, for example round in the case of a given display element. Therefore, at the outlet of the extrusion head, the plastic material, which is in a plastic-elastic state when it leaves the outlet, is passed through a forming device with two coplanar rotating heads to form the plastic material into a container. Give it the desired final shape. In this case, the forming apparatus further comprises a third forming head in perpendicular relation to the two coplanar rotary heads.

Since the method of the invention allows several plastic materials to be extruded simultaneously, it can be used with particular advantage in the production of display elements. Since in this case the bare electronic component is in fact a light emitting diode, such a container is obtained by coextruding a first transparent plastic material and a second plastic material containing a diffusing pigment.

Finally, another application of the invention concerns the encapsulation of bare electronic circuits; such an encapsulation method involves pre-coating the electronic circuit with a protective resin by spraying the resin.

In another application of the invention, the bare electronic component is a light emitting diode, and the container comprises a first transparent plastic material and a second opaque plastic material arranged on opposite sides of the first transparent plastic material. It is particularly characterized in that it is obtained by simultaneously extruding.

The container thus obtained thus has two opaque surfaces that can reflect a part of the light emitted by the light emitting diodes and direct it towards the front of the display element and thus towards the normal direction.

Additionally, a third plastic material containing a diffused pigment can be extruded simultaneously with the first and second plastic materials to form the bottom of the container.

Finally, the second opaque plastic material can be a transparent plastic doped with titanium oxide.

Next, the invention will be explained by way of example with reference to the drawings.

FIG. 1 shows the simple steps of a method for encapsulating a bare electronic component 11. FIG. In the example shown in FIG. 1, the component 11 is a light emitting diode. Such part 11 is in the form of a continuous strip 12 and is provided with containers 13, 14 of defined shape made of at least one plastic material 15. In FIG. 1, the plastic material 15 is extruded by an extrusion head 16 to form the containers 13, 1.
4 to the desired shape. The bare electronic component 11 is then placed in the container and immobilized, after which, as a final operation, the extruded plastic material 1 is
5 and the strip 12 of the above-mentioned component, the bare electronic component 1 with containers 13, 14 is formed as described above.
1 are separated from each other.

In a first embodiment of the invention shown in FIG. 2, the container of shaped plastic material 15 extruded from the extrusion head 16 has a groove 17. At the exit of the extrusion head, the groove is continuously filled with polymerizable filler resin 30. The bare electronic component 11 is then placed in the groove 17, after which the polymerizable filler resin 30 is polymerized to immobilize the component within the groove.

As shown in Figure 2b, the polymerizable filling resin 30 is a resin that can be polymerized by the action of ultraviolet light 19.

In the example of FIG. 2a, the bare electronic component 11 is pretreated with a polymeric curable resin 31 before being placed in the groove 17. In the example of FIG. Note that the resin 31 can be the same as the filling resin 30. This curable resin can also be photopolymerized.

FIG. 3 shows that a bare electronic component 11 is successively placed into a container of plastic material having an extruded shape by introducing said strip 12 of said component directly into an extrusion head, and that said component 11 is placed in a container of plastic material in the form of an extruded material. By storing the part 1 in
A second example of the present invention is shown in which immobilization of 1 is performed. In this example as well, before the bare electronic component 11 is introduced into the extrusion head 16, it can be pretreated with a polymerizable curable resin 31 (which can be photopolymerized), which can be subsequently polymerized.

An advantage of the embodiment of the invention shown in FIG. 3 is that the containers for bare electronic components 11 can each have the desired shape. As shown in FIG. 4, for example, in the case of a round container 13, a plastic material 15 is extruded according to the round shape, and the plastic material 15, which is in a plastic elastic state when extruded, is transferred to two rotating heads 20, 21 to give the plastic material the final cylindrical shape desired for container 13. In order to give the container a round cap, the forming device 23 further comprises a third forming head 24 in perpendicular relation to the two coplanar rotating heads 20,21.

The method described in FIGS. 1 to 4 is used in particular for manufacturing display elements by encapsulating light emitting diodes, the container of the display element containing a first transparent plastic material 25 and a diffusive pigment. It has the advantage that it can be obtained by simultaneous extrusion with the second plastic material 26.

More generally, the encapsulation method of the present invention has a variety of applications, which applications are determined by the bare electronic component to be encapsulated. In the case of a bare integrated circuit, the integrated circuit 11 can be sufficiently covered with the resin by spraying the protective resin 22 as shown in FIG.

The method of the invention can be implemented with active electronic components (power diodes, photocouplers, etc.) as well as with passive electronic components (eg resistors or capacitors).

FIG. 6 shows a bare electronic component 1 made of at least one plastic material 15 and present in the form of a continuous strip 12 to provide a defined shaped container.
1 is a perspective view showing a case where the method is applied to manufacturing a display element. As seen in Figure 6, bare electronic component 1
1 is a light emitting diode, and the container 13 is obtained by simultaneously extruding a first transparent plastic material 35 and a second opaque plastic material 36 arranged on both sides of the plastic material. As shown in the cross-sectional view of FIG. 7, surfaces 41 and 42 emitted by light emitting diode 11 and covered by opaque plastic material 36
The light rays reaching the display element are reflected in the direction of the output surface 43 of the display element, thus increasing such efficiency.

If the opaque plastic material 36 is a transparent plastic material, which can be identical to the transparent plastic material 35, it is advantageous to dope it with titanium oxide.

FIG. 8 shows another example in which a third plastic material 37 containing a diffused pigment is extruded simultaneously with the first plastic material 35 and the second plastic material 36 to form the bottom of the container 13.

FIG. 9 shows that the light rays reflected by the opaque plastic material 36 pass through the diffusing plastic material 37 before being directed towards the output surface 43 of the display element.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the method of the present invention, FIG.
The figure is an explanatory diagram showing a first example of the method of the present invention, Figure 2b is a partially enlarged view of the plastic material shown in Figure 2a, and Figure 3 is a second example of the method of the present invention. FIG. 4 is an explanatory diagram showing an operation for molding a container obtained by the method of the present invention. FIG. 5 is an explanatory diagram showing an example of application of the method of the present invention to an electronic circuit. FIG. 7 is an explanatory diagram showing a third example of the method of the present invention, FIG. 7 is a sectional view of a display element obtained by one example of the method of the present invention shown in FIG. 6, and FIG. FIG. 9, an explanatory drawing showing another example of the method of the invention, shows a cross-sectional view of a display element obtained by another example of the method of the invention shown in FIG. 11...Bare electronic component, 12...Continuous strip, 1
3, 14...container, 15...plastic material,
16...Extrusion head, 17...Groove, 19...
Ultraviolet rays, 20, 21... Rotating head, 22... Protective resin, 23... Molding device, 24... Third molding head, 25... First transparent plastic material,
26... Second plastic material, 30... Polymerizable filled resin, 31... Polymerizable curable resin, 35...
First transparent plastic material, 36... second opaque plastic material, 37... third plastic material, 41, 42... surface, 43... output surface.

Claims (1)

Claims: 1. A method for encapsulating a bare electronic component present in the form of continuous strips arranged in a primary direction, comprising applying at least one plastic material to the bare electronic component by means of an extrusion head. In a method for encapsulating a solid container having a defined shape obtained by extrusion parallel to the primary direction, the method of encapsulation is carried out substantially perpendicular to the primary direction in which the portions are arranged. the at least one bare electronic component 11 is successively encapsulated so that the encapsulation is limited to the component 11 excluding the hard connecting leads; As a final operation, the arrayed parts are placed and immobilized in a plastic material, and the continuous strip 12
A common portion of the plastic material 15 extruded from the extrusion head is placed in these containers 1.
A method for encapsulating a bare electronic component, characterized in that the bare electronic component 11 having the parts 3 and 14 is cut so as to be separated from each other. 2. Giving the plastic material 15 extruded from the extrusion head 16 a shape with grooves 17;
At the exit of the extrusion head, the groove is continuously filled with polymerizable filling resin 30, and then the bare electronic component 1 is filled.
2. A method according to claim 1, wherein the part is placed in the groove 17 and the polymerizable filler resin 30 is then polymerized to immobilize the part in the groove. 3. The encapsulation method according to claim 2, wherein the bare electronic component 11 is pretreated with a polymerizable curable resin 31 before being placed in the groove 17, and the polymerized curable resin is polymerized. 4. The capsule sealing method according to claim 2, wherein the polymerizable filling resin 30 is a photopolymerizable resin. 5. A bare electronic component 11 is continuously produced by introducing said strip 12 of said component directly into an extrusion head 16 into a plastic material 1 having an extruded shape.
Claim 1 wherein the immobilization of the part 11 is effected by placing the part 11 in a container of 5 and encapsulating the part 11 within the plastic material itself.
Encapsulation method described in section. 6. The encapsulation method according to claim 5, wherein the bare electronic component 11 is pretreated with a polymerizable curable resin 31 before being introduced into the extrusion head 16, and then the polymerized curable resin is polymerized. . 7. The encapsulation method according to any one of claims 3 to 6, wherein the polymerizable curable resin 31 is a photopolymerizable resin. 8 At the outlet of the extrusion head 16, the plastic material 15, which is in a plastic-elastic state when exiting the outlet, is moved between two coplanar rotating heads 20,
8. Encapsulation method as claimed in claim 6 or 7, in which the plastic material is passed through a forming device (23) having a forming device (21) to give the final desired shape to the container (13). 9. The encapsulation method according to claim 8, wherein the molding device 23 further comprises a third molding head 24 perpendicular to the two rotary heads 20, 21 on the same plane. 10 For the manufacture of a display element, a light emitting diode is used as the bare electronic component 11 and the containers 13, 14 are made of a first transparent plastic material 25.
and a second plastic material 26 containing a diffused pigment.
The encapsulation method according to any one of claims 1 to 9, obtained by simultaneously extruding the encapsulation method. 11. Regarding the encapsulation of the bare electronic circuit 11, the encapsulation method according to any one of claims 5 to 9, wherein the bare electronic circuit is coated in advance by spraying the protective resin 22. 12 The bare electronic component 11 is a light emitting diode,
the container 13 with a first plastic material 35;
A method as claimed in claim 1, obtained by simultaneously extruding a second opaque plastic material 36 arranged on both sides of the first plastic material. 13 Third plastic material 3 containing diffused pigments
13. The method of claim 12, wherein the plastic material 7 is extruded simultaneously with the first plastic material 35 and the second plastic material 36 to form the bottom of the container 13. 14. Encapsulation method according to claim 12 or 13, wherein the second opaque plastic material 36 is a transparent plastic material doped with titanium oxide.