DE102008009808A1 - LED-light strip, has casting compound presented as contoured casting compound, where process of electromagnetic shaft is determined by contoured casting compound, and LED air-tightly locked by compound compared to substrate or plate - Google Patents

Abstract

The strip (10) has a substrate (20) i.e. flexible substrate, a plate (30), and an LED (50) emitting electromagnetic waves (40). A casting compound (60) is presented as a contoured casting compound (61), where a process of the electromagnetic shaft is determined by the contoured casting compound. The LED is air-tightly locked by the contoured casting compound compared to the substrate or the plate, where the contoured casting compound includes a set of material components. The contoured casting compound is applied on an upper surface of the substrate. An independent claim is also included for a method for manufacturing an LED-light strip.

Description

The The present invention relates to an LED light bar, or to a process for producing the same.

The published patent application is known from the prior art DE 10 1005 041 333 A1 which describes a waterproof illuminant insert with at least one light-emitting element and at least one light exit surface. Disadvantage of this invention is that special separate Lichtstreumittel must be used to scatter the light emitted by a diode light.

task The invention is an LED light strip with an improved Provide radiating property that is easier to handle is.

These Task is achieved by the device according to the invention or the inventive method according to the solved independent claims. Further advantageous embodiments of the invention are in the dependent Claims defined.

According to a first aspect of the present invention, an LED light strip ( 10 ) comprising a substrate ( 20 ), a board ( 30 ), at least one electromagnetic wave ( 40 ) emitting LED ( 50 ), a potting compound ( 60 ), the potting compound ( 60 ) a contoured potting compound ( 61 ), by which the course of the electromagnetic waves ( 40 ) is determinable.

advantage of this invention is that no optical elements, such as Lenses or the like, must be used to a desired emitted by the or the LEDs beam path, or beam path to create. The steering or deflection of the electromagnetic Blasting is solely by a preferred contoured potting compound reached.

Under An LED light bar is an arrangement of LEDs on one geometric plane, in or on or in a geometric Body. The LEDs are preferably on a board or applied to several boards, which in turn preferably on a Carrier material or multiple carrier materials are applied.

The used LEDs can be a variety of semiconductor materials and dopants. For example, the semiconductor materials used are Aluminum gallium arsenite (AlGaAs), gallium aluminum arsenite (GaAlAs), Gallium arsenite phosphite (GaAsP), aluminum indium gallium phosphite (AlInGaP), Gallium phosphide (GaP), silicon carbide (SiC), zinc selenite (ZnSe), Indium gallium nitride (InGaN), gallium nitride (GaN), copper plumbide (CuPb). Furthermore, there is the possibility of using white LEDs, which are mostly blue LEDs with a phosphor layer, which act as Lumineszenzkonverter are. The from the LED or radiation emitted by the LEDs is in the range between 280 nm and 1000 nm. Preferably understood by LEDs also finished SMD components.

Prefers the LEDs are arranged side by side or inclined to each other or tilted away from each other, particularly preferably with the same distance applied to each other on a board, for example in shape a field, most preferably arranged in a straight line on the board arranged. Preferably, several are arranged in straight lines LEDs side by side combined into a light band. The distances the individual LEDs are preferably between 5 mm and 20 cm, more preferably between 10 mm and 10 cm, most preferably between 2 cm and 5 cm.

The PCB forms the basis for the arrangement of the LEDs. On The LEDs are attached to the board. This happens preferably by reflow soldering. On the board are further preferably integrated circuits. The board is preferably one Surface, which preferably the geometry of the support material adapts, more preferably runs parallel to this. The board or the boards are preferably on a carrier material attached, more preferably pinned, most preferred glued on, further preferably only hung up.

The Support material is preferably made of a metal, especially preferably made of plastic; wood is also conceivable. This is preferred Support material an aluminum profile or an aluminum support. In cross section, the carrier material is preferably a straight line, most preferably a domed line, most preferred a U-shaped profile, further preferably a circular arc (also circle) or an elliptical arc (also ellipse) or parts of a Polygons or a hyperbola or a parabola or a cross section a handrail. Preferably, the surface runs the board parallel to the surface of the carrier material, or the carrier, particularly preferably covers the board nut parts of the carrier material, most preferably the entire carrier material.

The potting compound preferably has several functions. The potting compound preferably provides the LED, or the board, or the carrier material, moisture protection or impact protection or scratch protection or corrosion protection. The potting material preferably encloses the LEDs, more preferably the board, most preferably the carrier material. Preferably, the potting compound is capable of the LEDs with their board on the Trägerma to attach material. In this case, the potting compound preferably overlaps the edges of the board and connects to the carrier material. An additional adhesive or an additional connecting means between the board and the carrier material is omitted in this case. The potting compound is preferably made of transparent plastic, more preferably of transparent epoxy resin or silicone rubber, most preferably of transparent polyurethane (polyurethane).

Prefers the epoxy resin has a high mechanical strength and hardness, Good adhesion and is therefore preferred with its scratch-resistant and protective properties for coating SMD components suitable. Silicone rubber preferably has a high permanent elasticity and a high temperature resistance. Preferably developed Silicone rubber when curing only low heat and is therefore particularly suitable for temperature-sensitive components suitable. Polyurethane preferably has good mechanical and chemical properties Stability, variable elasticity is preferred perfectly clear (ie transparent) and has a low heat development and volume shrinkage during the curing process. Therefore Polyurethane is preferred for the coating of sensitive SMD components suitable and by the transparent consistency to Light pipe suitable without major losses.

The Potting compound has a purity or a light transmission from preferably 70 to 99%, particularly preferably from 80 to 99%, on most preferably from 90 to 99%. Here is the translucency or the transmittance preferably depends on the thickness the potting compound. A thickness of the potting compound (shortest Distance from LED to potting compound contour) from 0.2 mm to 10 mm, especially preferably from 0.5 mm to 8 mm, most preferably from 1 mm to 2 mm used.

The optical refractive index of the potting compound is preferably between 1.2 and 1.9, more preferably between 1.3 and 1.8, most preferably between 1.4 and 1.7.

The Potting compound is preferably a contoured potting compound. That means, that the potting compound due to its contour (transition potting compound - air) a specific light profile (course of electromagnetic radiation) which can specify the electromagnetic radiation emitted by the LED. The contour of the potting compound is shaped so that all emitted electromagnetic rays of the LED or LEDs after Depending on the application before given to the escape from the potting compound focused, especially preferred to be dispersed. To be favoured the electromagnetic rays in any two-dimensional focused on a geometric figure, such as a straight line, a rectangle, a circle, a dot, a polygon, ... etc. However, the electromagnetic radiation is preferably also through the contoured potting compound scattered. In the cross section of the LED light bar considered, the scattering angle is preferably between 30 ° and 180 °, more preferably between 45 ° and 150 °, most preferably between 60 ° and 120 °. Thus, the full angle is preferred over both halves of the axle described from the LED.

The Potting compound can take on a wide variety of contour shapes. Preferably, the Vergussmassekontur is a circular arc section or a Ellipse arc section. These sections are preferably spherical, more preferably aspheric to one LED or shaped against multiple LEDs. The bow sections preferably have no constant radius, particularly preferably a constant radius, most preferably a combination it. Preferred is a larger beam divergence generated at spherical shapes, when the arc radius is greater is the distance LED to the apex of the potting compound. Prefers The radiated electromagnetic waves of the LED are focused when the arc radius is smaller than the distance LED to the vertex the casting compound contour. Furthermore, they are preferably prismatic Structures with different angular variations as potting compound contour possible. In this case, the emission characteristic is preferred adapted to specific lighting distributions. The above Casting compound contours, which have always been described in cross-section, preferably retain in linear design, d. H. if goes into the depth of the cross section, not the same shape. Prefers are the Vergussmassekonturen rotationally symmetrical structures, which associated with the light origin points of the individual LEDs. Thereby an even more efficient decoupling of light is allowed since the whole emitted light or the entire emitted electromagnetic radiation also in the longitudinal direction of the LED light bar to the outside can be steered and not in the longitudinal direction of the Inside the Vergussmassekontur is totally reflected.

In a further preferred embodiment, an LED light strip is provided, wherein at least one LED ( 50 ) of the contoured potting compound ( 61 ) relative to the carrier material ( 20 ) or the board ( 30 ) is airtight lockable.

The LED light strip is preferably constructed so that there is no air gap between the LED and the potting compound. The LED is preferably completely embedded in the potting compound, so that the LED is integrated into the potting compound without play. Preferably, the LED is embedded in the potting compound that the potting compound is also between the board and LED and only make the connecting wires and thermal contact surfaces an additional connection between the two elements board and LED. The advantage of the hermetic seal is that no radiation losses occur at the transition LED potting compound due to the presence of air. The electromagnetic waves emit preferably from the LED directly into the potting compound. However, the potting compound preferably encloses not only the LED, but also the circuit board and the carrier material. Due to the fact that the contoured potting compound preferably ends with the carrier material, damage to the board or the LED as a result of external or atmospheric influences is largely ruled out.

In a further preferred embodiment, an LED light strip ( 10 ), wherein the contoured potting compound ( 61 ), at least one first material component ( 62 ) and a second material component ( 63 ) having.

When Material component refers to a potting compound which independently can be used as potting the LED light bar or in Combination with other material components (potting compounds) in mixed form or layer form may occur as a combined potting compound. Consequently, a composite potting compound consists of at least two material components. The different material components are preferably in separate form in the potting compound, especially preferably in mixed form in the potting compound. In cross section by the Vergussmasseprofile preferably the edges are left and right from a first material component and the middle part from a second material component. Here, for example, is the outer first material component harder than the second middle one Material component, d. H. has a different material property on. The outer first material component can for example, to attach the board to the substrate used or used to protect the middle second material component become. Furthermore, in this form, the outer second material component of lesser quality in relation to be on optical abilities, because these are not preferred contributes to the light conduction of the emitted electromagnetic waves.

Of Furthermore, there is preferably the possibility of the two material components to arrange so that, for example, the first material component the LED and the circuit board surrounds and the second material component the first component is applied in a kind of sandwich structure. This could, for example, the steering of the emitted electromagnetic rays in the transition from the first Material component influenced in the second material component become. Preferably, the first and the second material components different refractive indices.

The second material component is preferably a transparent plastic. This plastic is cast, for example, in a linear profile, which already contains an outer contour and, taken in isolation, an optical function has, especially preferred by itself, no optical Function has. Preference is given to the casting between LED and introduced said plastic profile. It is preferred the optical effect, d. H. the emission characteristic, preferably by determines the refractive index of the material components, more preferably through the outer contour of the plastic profile determined, most preferably by a combination of the refractive indices of Material components and the outer contour of the Plastic profiles determined. It would be the inner contour the plastic profile of minor importance, as long as the Refractive index difference between the two material components relative low would be. In this way, while maintaining efficiency a higher hardness or strength of the optical Outside surface can be achieved.

In a further preferred embodiment, an LED light strip ( 10 ), wherein the contoured potting compound ( 61 ) a potting compound which changes in cross-section ( 64 ).

The Potting compound may be preferred in cross-section with respect to material, particularly preferred in terms of refractive index, most preferably in Terms of density, change. Preferably, the changes Potting compound in the cross section vertical, more preferably horizontal, most preferably in a combination of both. For example, the potting compound changes in the cross-sectional profile as follows: For example, the potting compound consists of a first material component in direct LED proximity. The further you look in the cross section wanders towards potting compound contour, goes the first Material component in a second material component via. In this case, the potting compound, for example, on a quarter the distance LED casting compound contour of 75% from the first material component and 25% of the second material component, in half 50% of the first material component and 50% from the second material component, at three quarters of the way 25% of the first material component and 75% of the second material component, or directly to the Vergussmassekontur to 100% from the second material component.

The advantage of being in cross-section Changing potting compound is preferably a better coupling-out efficiency in the longitudinal direction, since less total reflection occurs. Preferably, a potting compound that changes in cross-sectional shape is used as the second material component and used as an outer potting layer as a scattering component for homogenizing the light exit surface.

In a further preferred embodiment, an LED light strip ( 10 ), wherein the contoured potting compound ( 61 ) a cross-sectional shape ( 65 ), by which the total reflection losses can be minimized to less than 35%.

In a further preferred embodiment, an LED light strip ( 10 ), wherein the contoured potting compound ( 61 ) on a surface ( 21 ) of the carrier material ( 20 ) is applied.

Prefers the contoured potting compound is applied to a surface, which means that the potting compound facing this surface is sublime. The advantage of this embodiment is that thereby the scattering angle of the occurring electromagnetic radiation can be increased and not by example Side walls which forms the carrier material disturbed becomes. Furthermore, the application of a contoured potting compound on a surface of a substrate the Advantage that the design freedom of the contour is a great Free space is left, and thus the light profile variable is.

In a further preferred embodiment, an LED light strip ( 10 ), wherein the carrier material ( 20 ) a bendable carrier material ( 21 ).

By the bending of the carrier material is preferably the contour the potting compound influenced and thereby the focus or the Dispersion of emitted electromagnetic waves influenced. Bending preferably changes the beam profile.

According to a further aspect of the present invention, a method for producing an LED light strip ( 10 ) comprising a substrate ( 20 ), a board ( 30 ), at least one electromagnetic wave ( 40 ) emitting LED ( 50 ), a potting compound ( 60 ), wherein a light profile ( 41 ) of the electromagnetic waves ( 40 ), a potting compound contour ( 66 ), a negative potting compound contour ( 67 ) into a forming tool ( 80 ), the potting compound ( 60 ) in the forming tool ( 80 ), the at least one LED ( 50 ) with board ( 30 ) and support material ( 20 ) into the potting compound ( 60 ) is immersed, and the potting compound ( 60 ) is cured.

When Light profile is preferably the two-dimensional projection of emitted denotes electromagnetic radiation from one or more LEDs, which hit a surface. This light profile is preferred a static light profile, more preferably a dynamic light profile Light profile. As a static light profile one calls oneself non-changing, for example, geometric shape, which by the emitted electromagnetic radiation and the deflection by the contoured potting compound is formed. As already in the device description the application has been described, the components of the LED light bar in a preferred embodiment on a bendable Applied carrier material. By bending, for example of the carrier material during the simultaneous emission of preferably light, for example, could be a first projected Circle after bending describe an ellipse. By example Bending the substrate by preferably an actuator, especially preferably by hand, can beipielsweise between the light profile Circle and the light profile ellipse, d. H. depending on the state of bending of the carrier material can be varied. Thus, preference is given create a dynamic light profile.

After this a particular light profile has been chosen, will be out of this Light profile preferably a Vergussmassekontur in conjunction with the positioning of LEDs on the board is calculated. The casting compound contour is preferably determined so that the electromagnetic radiation radiating through the potting compound Waves describe exactly the selected light profile.

Around It is preferred to be able to produce the potting compound contour necessary to introduce a negative Vergussmassekontur in a forming tool. Preferably, the Vergussmassekontur is introduced by forming in the forming tool. The forming methods used are preferably pressure forming, especially preferably tensile forming, most preferably pressure forming, of Further preferred bending forming. Furthermore, the Vergussmassekontur through mechanical processing such as milling or thermoforming or polishing or made by a combination.

The Introducing the potting compound in the forming tool happens preferably by casting or die casting or injection molding or extrusion.

The immersion of the at least one LED with board and / or carrier material in the potting compound is done as long as the potting compound is still liquid. The casting compound has been preferred a temperature between 18 ° C and 26 ° C, more preferably between 18 ° C and 30 ° C, most preferably between 18 ° C and 26 ° C.

Prefers is the at least one LED with board and / or substrate immersed several times in the same potting compound, especially preferably immersed several times in different potting compounds.

The Curing of the potting compound moves in a period of time from 90 seconds to 30 minutes.

The Curing is preferably done in the absence of air, especially preferably in the air, most preferably with heated air, further preferably with irradiation or in a combination of four curing processes. Preference is given to the potting compound cured in a temperature range of 18 ° C to 26 ° C.

In a further preferred embodiment, a method is provided, wherein the method steps introducing the potting compound ( 60 ) in the mold ( 80 ) and immersing the at least one LED ( 50 ) with board ( 30 ) and support material ( 20 ) into the potting compound ( 60 ) at the same time.

Prefers is the LED with board and substrate at Introducing the potting compound at a height in the forming tool, so that the introduction of the potting compound with the immersion time coincides. The advantage of this is that fast-curing Casting compounds can be used.

Further preferred embodiments are shown in the following figures described. The figures show:

1 a cross section through an LED light bar

2 a cross section through an LED light bar

1 shows a schematic representation of a cross section through an LED light bar 10 , In cross-section is a carrier material 20 Made of aluminum, on which a standard board 30 glued for LEDs, on which an LED 50 located by chip bonding to the board 30 was connected. Above the LED 50 with the board 30 and the carrier material 20 rises a potting compound 60 made of epoxy resin, which has a Vergussmassekontur 61 has, which represents a circular arc section in the middle part, wherein the radius center is below the carrier material 20 located.

The LED 50 emits electromagnetic radiation in the wavelength range between 380 nm and 750 nm, ie visible light. The electromagnetic radiation 40 leaves the LED with a design-related scatter angle. As the radius of Vergussmassekontur 61 below the carrier material 20 is located and so that the distance LED - Vergussmassekontur is smaller than the circular arc radius, the electromagnetic radiation 40 after exiting the potting compound 60 scattered even further, ie that the scattering angle, which originally due to the design of the LED 50 was given by the Vergussmassekontur 61 was enlarged. Advantage of this design is that the effect described solely by the contoured potting compound 61 and without the help of special optics (scattered lenses) can be achieved.

2 shows a cross section through an LED light bar 10 which consists of a single LED or of a single SMD component 51 which is on a U-shaped substrate 20 is applied. The carrier material 20 is an aluminum U-profile, which in the lower quarter already from the potting compound 60 is included. The potting compound 60 is a contoured potting compound 61 , The arc of the outer contour includes an angle of 160 ° with a radius of 5 mm, then close to straight sections, which thus enclose an angle of 20 °. The outer contour area is hardly relevant visually. As an SMD component 51 comes a so-called. TOP LED (this is a type designation of the company Osram) is used, which has a nearly flat circular light exit surface 52 (Conversion layer) having a diameter of about 2.5 mm and preferably emits white light in a long-controlled radiation characteristic. Ie. the emission angle of the SMD component 51 is 120 ° and is rotationally symmetrical, just like the potting compound 60 , which gives a circle in plan view. The distance between LED or better SMD component 51 and vertex of Vergussmassekontur 61 is about 7.5 mm and thus acts focusing.

Thus, the scattering angle of the electromagnetic radiation after the exit from the potting compound 60 reduced or focused. The LED light exit surface is located here 52 exactly 2.5 mm below the arc center of the casting compound contour 61 , In doing so, the rays, viewed in the two-dimensional sectional plane, which meet the circular arc are focused and the rays, which are perpendicular to the contour surfaces 68 do not hit in their direction. The contour area 68 is the area of the contoured potting compound 61 which includes an angle of 20 °.

10

LED light strip

20

support material

21

surface of the carrier material

30

circuit board

40

electromagnetic waves

41

Lichtprofil

50

LED

51

SMD

52

Light-emitting surface

60

potting compound

61

contoured potting compound

62

First material component

63

Second material component

64

Yourself Cross-section changing potting compound

65

Cross-sectional shape

66

Vergussmassekontur

67

negative Vergussmassekontur

68

Contour subarea

80

shaping tool

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• - DE 101005041333 A1 [0002]

Claims (10)

LED light strip ( 10 ) comprising a substrate ( 20 ), a board ( 30 ), at least one electromagnetic wave ( 40 ) emitting LED ( 50 ), a potting compound ( 60 ), characterized in that the potting compound ( 60 ) a contoured potting compound ( 61 ), by which the course of the electromagnetic waves ( 40 ) is determinable. LED light strip ( 10 ) according to claim 1, wherein the at least one LED ( 50 ) of the contoured potting compound ( 61 ) relative to the carrier material ( 20 ) or the board ( 30 ) is airtight lockable. LED light strip ( 10 ) according to one of claims 1 or 2, wherein the contoured potting compound ( 61 ), at least one first material component ( 62 ) and a second material component ( 63 ) having. LED light strip ( 10 ) according to one of claims 1 to 3, wherein the contoured potting compound ( 61 ), a potting compound which changes in cross-section ( 64 ). LED light strip ( 10 ) according to one of claims 1 to 4, wherein the contoured potting compound ( 61 ), a cross-sectional shape ( 65 ), by which the total reflection losses can be minimized to less than 35%. LED light strip ( 10 ) according to one of claims 1 to 5, wherein the contoured potting compound ( 61 ) on a surface ( 21 ) of the carrier material ( 20 ) is applied. LED light strip ( 10 ) according to one of claims 1 to 6, wherein the carrier material ( 20 ) a bendable carrier material ( 21 ). Method for producing an LED light strip ( 10 ) comprising a substrate ( 20 ), a board ( 30 ), at least one electromagnetic wave ( 40 ) emitting LED ( 50 ), a potting compound ( 60 ), comprising the following steps: • selecting a light profile ( 41 ) of the electromagnetic waves ( 40 ) • determining a potting compound contour ( 66 ) • introducing a negative casting compound contour ( 67 ) into a forming tool ( 80 ) • introduction of potting compound ( 60 ) in the forming tool ( 80 ) • Immerse the at least one LED ( 50 ) with board ( 30 ) and / or carrier material ( 40 ) into the potting compound ( 60 ) • hardening of the potting compound ( 60 ) Process according to claim 9, wherein at least two different potting compounds ( 62 and 63 ) are introduced into the forming tool. Method according to one of claims 9 or 10, wherein the method steps introducing the potting compound ( 60 ) in the forming tool ( 80 ) and immersing the at least one LED ( 50 ) with board ( 30 ) and support material ( 40 ) into the potting compound ( 60 ) at the same time.