Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C39/00—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor
  • B29C39/02—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor for making articles of definite length, i.e. discrete articles
  • B29C39/10—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor for making articles of definite length, i.e. discrete articles incorporating preformed parts or layers, e.g. casting around inserts or for coating articles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C33/00—Moulds or cores; Details thereof or accessories therefor
  • B29C2033/0005—Moulds or cores; Details thereof or accessories therefor with transparent parts, e.g. permitting visual inspection of the interior of the cavity
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C35/00—Heating, cooling or curing, e.g. crosslinking or vulcanising; Apparatus therefor
  • B29C35/02—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould
  • B29C35/08—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation
  • B29C35/0805—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation using electromagnetic radiation
  • B29C2035/0827—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation using electromagnetic radiation using UV radiation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/0053—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor combined with a final operation, e.g. shaping
  • B29C2045/0075—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor combined with a final operation, e.g. shaping curing or polymerising by irradiation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C35/00—Heating, cooling or curing, e.g. crosslinking or vulcanising; Apparatus therefor
  • B29C35/02—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould
  • B29C35/08—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation
  • B29C35/0888—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation using transparant moulds
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/14—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles
  • B29C45/14639—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles for obtaining an insulating effect, e.g. for electrical components
  • B29C45/14655—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles for obtaining an insulating effect, e.g. for electrical components connected to or mounted on a carrier, e.g. lead frame
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2011/00—Optical elements, e.g. lenses, prisms
  • B29L2011/0016—Lenses
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
  • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
  • H01L33/52—Encapsulations

Definitions

• the invention lies in the field of LED technology (Light Emitting Diode) .
• LED technology Light Emitting Diode
• chip on board a technique known as "chip on board” in combination with a lens for the purpose of obtaining the desired directional characteristic, for instance a semi-spherical lens.
• Polycarbonate for the material of the lens is known.
• Polycarbonate has the drawback that, in the case of high-power applications and at radiation in the wavelength range of about 400-430 nm, it displays a relatively rapid ageing, in particular a yellowish discoloration.
• a mould transparent to UV radiation use is further made of a mould transparent to UV radiation.
• a suitable material for the mould is a silicone rubber.
• the manufacture of a lens takes place by making a master mould on the basis of ceramic balls on a metal substrate, making a silicone rubber working mould therefrom and using this, after enclosure in an aluminium mould with recesses, for the purpose of injecting said lens material.
• Use is made of injection needles which can pierce through narrow openings in the mould material in order to carry the more or less oily viscous acrylate material under some pressure through the needle into the mould cavities. Irradiation with UV radiation then takes place through the walls of the mould.
• the initially liquid acrylate basic material is hereby cured, so that a cured lens of acrylate material with the desired shape is obtained.
• the silicone rubber exhibits a certain (slight) shrink. This must be taken into account when dimensioning the master mould. The relevant dimensions must therefore be increased by the same amount as the shrink of the silicone rubber.
• An excellent flow over a surface can be realized by using a plasma treatment in an argon/oxygen environment.
• An easy release is obtained by adding a small quantity of silicone oil to the silicone rubber material.
• Such a material is available on the market as bleeding silicone rubber.
• the described method can be described as "liquid moulding”.
• All types of lens can be made according to the described method, except those with an undercut or other non-releasing form.
• manufacture hereof it is possible to work in two stages, i.e. first making a first structure which is subjected to a basic curing, subsequently making a second structure which is to be placed thereon and which is also subjected to a basic curing, and finally a final curing in a UV chamber with a high UV-intensity.
• the timing of the UV radiation is critical.
• the material according to the invention adheres in practically ideal manner to silver, gold and ceramic. Any form of roughness ⁇ etching ⁇ is not necessary.
• the surfaces may be as smooth as glass.
• a studio lamp for television studio applications can comprise an array with LEDs of different colours.
• the array can be controllable, whereby within certain limits substantially all intensities and colours can be realized.
• the same principle can also be applied for household use.
• the method according to the invention is extremely flexible and very widely applicable.
• the invention also relates to a lens obtained by applying the described method.
• figure 1 shows a top view of a LED lighting element with LEDs provided with lenses according to the present invention
• figure 2 shows a side view of the LED lighting element of figure 1
• figure 3 shows the side view of the LED lighting element of figure 2 during a step in the manufacture thereof
• figure 4 shows the side view of the LED lighting element of figure 2 during a further step in the manufacture thereof
• figure 5 shows a cross-section of a mould of aluminium and silicone material for the manufacture of the lens according to the present invention
• figure 6 is a perspective view of the mould of figure 5
• figure 7 shows a lens manufactured with the method according to the present invention
• figure 8 shows a lens manufactured with the method according to the present invention
• figure 9 shows a lens manufactured with the method according to the present invention
• figure 10 shows a lens manufactured with the method according to the present invention
• figure 11 shows a cross-section of a mould of crystal glass for manufacturing the lens according to the present invention
• figure 12 shows a perspective view
• FIG. 1 shows a top view of a LED lighting element 1 with LEDs provided with lenses 4 according to the present invention.
• LED lighting element 1 comprises a printed circuit board 2 provided with a printed circuit 5 to which the LEDs are connected. Arranged on the LEDs are lenses manufactured making use of the method according to the invention.
• Figure 2 shows a side view of the LED lighting element 1 of figure 1.
• Figure 3 shows a side view of the LED lighting element of figure 2 during a step in the manufacture thereof, wherein a LED 7 is provided on printed circuit board 6.
• LED 7 is not yet provided with a lens.
• a phosphor-comprising layer 8 has however been applied, this contributing on the one hand to the adhesion of the lens to be arranged in a following step (see figure 4 ⁇ and helping on the other to increase the light output of the LED lighting element to be thus obtained.
• the phosphor-comprising layer 8 is applied over the whole width of printed circuit board 6. In a practical situation it is however possible to opt for application of this layer 8 around LEDs 7 with only a small overlap.
• Figure 4 shows the LED lighting element of figure 3 during a step in the manufacture thereof, wherein an acrylate material 9 is arranged on the phosphor- comprising layer 8 for the purpose of forming the lens.
• the acrylate material is applied in this example over the whole width of the printed circuit board.
• the formed lenses are however concentrated around the LEDs 7 themselves, and only connected to each other by means of a network of channels suitable for the injection.
• Figure 5 shows a first embodiment of a mould for applying the acrylate material for the purpose of forming the lenses.
• the mould consists of a lower mould part 10 and an upper mould part 13, both preferably, though not exclusively, embodied in aluminium.
• the mould parts are provided with holes 11 for dowels.
• a recess 12 for arranging therein of a printed circuit board.
• a transparent mould part 14 which is provided with at least one filling opening 15 for the acrylate material, and a venter or riser pipe 16 for the acrylate material.
• the transparent mould part comprises the recesses 17 for the lenses to be formed on the LEDs provided on the printed circuit board.
• FIG. 6 shows a perspective view of a mould which is similar to the mould of figure 5 and which is adapted to manufacture a plurality of LED lighting elements simultaneously, and is provided for this purpose with compartments 12a-12g.
• Figures 7-10 show diverse embodiments of lenses, wherein a first part 20b of the lens is formed according to the above described method, wherein lens 20b is arranged on a LED 19 provided on a printed circuit board 18, and a second part 20a is manufactured in a separate mould or a separate mould part.
• the first and the second mould part are urged against each other in not yet fully cured state, whereby they adhere to each other.
• a final curing is subsequently obtained by means of further exposure to UV radiation.
• the embodiments shown in figures 7-10 can also be manufactured according to an alternative method, wherein the flexible mould part 14 can be taken apart and consists of a plurality of parts.
• Figure 11 shows a completely hard mould, preferably formed from quartz glass, consisting of a first mould part 21 and a second mould part 22, both of which mould part are provided with holes 23 for centering pins for mutual alignment of the mould parts. Quartz glass is preferred because of the excellent UV-transmitting properties thereof.
• First mould part 21 is provided with a recess 21a for a printed circuit board, and second mould part 22 comprises recesses 26 for the purpose of forming the lenses. Recesses 26 can be filled using the respective filling opening 24 and riser pipe 25 for the acrylate material.
• the mould is provided with compartments 21a - 21g for containing a plurality of printed circuit boards with LEDs.
• FIG 13 shows a flow diagram of the method for manufacturing a lens according to the present invention.
• Step 27 here shows the feed of printed circuit boards, which are subjected in step 28 to a plasma cleaning.
• a printed circuit board is placed in a mould, such as a mould as shown in figures 5, 6, 11 or 12, after which in step 30 a first layer of material, for instance a phosphor-comprising layer, is applied as shown in figure 3.
• a first layer of material for instance a phosphor-comprising layer
• step 31 the first layer of material is caused to cure and in step 32 a scond layer of material is then applied, in particular an acrylate material, as shown in figure 4.
• the method according to the present invention can have the particular feature that the acrylate material is provided with a sinter material, formed particularly by globules, for instance formed from titanium, neodymium or lanthanum. These globules preferably have a diameter of about 20 micrometres, and have facets.
• the arranging of these globules, for instance between 0.1 and 0.2 g per 50 cc acrylate material, results in an improved light output, and particularly in an improved refractive index of the lens. Where between 1.5 and 1.6 is normally achieved, it has been found possible to achieve a refractive index between 1.95 and 2.00 by means of adding the globules according to the invention.
• a first curing of the acrylate material is obtained by exposing the mould with the acrylate layer received therein to LJV radiation until the thus formed lens is form-retaining, and in step 34 can be taken out of the mould.
• the mould is used once again and in step 29 again placed in a mould in which a printed circuit board is arranged.
• the lens is meanwhile in a step 35 further cured under the further influence of UV radiation, or in accordance with another suitable curing method.
• the thus obtained end product is further transported for incorporation in step 37 into for instance light fittings or other light units-

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• Led Device Packages (AREA)
• Casting Or Compression Moulding Of Plastics Or The Like (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=41078279

Family Applications (1)

Country Status (4)

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Family Cites Families (7)

• 2009
  • 2009-06-15 WO PCT/NL2009/050344 patent/WO2010005294A1/en active Application Filing
  • 2009-06-15 NL NL2003027A patent/NL2003027C/nl not_active IP Right Cessation
  • 2009-06-15 EP EP09794684A patent/EP2310175A1/en not_active Withdrawn
  • 2009-06-15 EA EA201100047A patent/EA019225B1/ru not_active IP Right Cessation

Non-Patent Citations (1)

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