WO2018149963A1 - Radiation emitting filament with heat conducting element - Google Patents

Abstract

The invention relates to a radiation emitting filament (100) with a support (120), wherein at least two light chips (110) are arranged on the support (120), wherein the support (120) has an electrical contact (150, 155) at each opposing end, wherein the light chips (110) are electrically conductively connected to the contacts (150, 155), wherein the support (120) with the light chips (110) is arranged in a through hole (170) of a heat conducting element (180), wherein the heat conducting element (180) is made from a material which is transparent for the electromagnetic radiation from the light chips (110), wherein the support (120) is mounted on the heat conducting element (180), and wherein the heat conducting element (180) is made from a material which has a higher thermal conductivity than helium.

Description

 RADIATION-EMITTING FILAMENT WITH HEATING ELEMENT

DESCRIPTION

The invention relates to a radiation-emitting filament, a method for producing a radiation-emitting filament and a luminous means with a radiation-emitting filament.

This patent application claims the priority of German patent application DE 10 2017 103 431.5, which is dependent Offenbarungsge ^¬ hereby incorporated by reference.

It is known in the prior art to provide a radiation-emitting filament in a luminous means. For verbes ^¬ ved thermal conduction lamps helium gas is turned Schlos ^¬ sen. This improves heat dissipation from the filament.

An object of the invention is to provide an improved radiation-emitting filament in particular ^¬ sondere allows for better heat dissipation. Another object of the invention is to provide a simple process for producing a radiation-emitting filament with improved heat dissipation. In addition, the object of the invention is to provide a light source with a radiation-emitting filament with improved heat dissipation.

The object of the invention is achieved by the independent claims. Advantageous developments are specified in the dependent claims.

One advantage of the proposed radiation-emitting filament is that with simple means verbes ^¬ serte heat dissipation is achieved. This is achieved in that the carrier is arranged with the light-emitting chips in a thermal conducting ^¬ element. For this purpose, the heat conduction element a through hole on. The electrical contacts of the carrier are accessible from both sides for an electrical connection. The arrangement of the carrier with the luminescent chips in the heat conduction element, the heat is transferred with a short bridging path to the heat conduction element. The heat conduction element is formed from a material which has ei ^¬ ne higher thermal conductivity than helium.

The radiation-emitting filament has a carrier with at least two light-emitting chips. The carrier has at each ^¬ opposite ends to a respective electrical contact. The light chips are with the electrical contacts

electrically connected. The heat conduction element is formed from a material which is transparent to the electromagnetic radiation of the luminescent ^¬ chips. Due to this arrangement, an improved heat dissipation from the filament, that is achieved by the light-emitting chips.

In one embodiment, the heat conducting element is formed of glass. Glass has a thermal conductivity that is, for example, in the range of 0.5 watts per millikelvin. Thereby, a sufficient heat dissipation and Küh ^¬ development of the light-emitting chips is achieved on the support.

In a further embodiment, the luminescent chips and / or the carrier have a luminescent layer. The luminescent layer is designed to shift a wavelength of the electromagnetic radiation of the luminescent chips. In this way, regardless of the wavelength of the radiation of the luminescent chips, a desired color, in particular white light, can be ^generated . The luminescent layer has, for example, red phosphor as luminescent material. Depending on the selected embodiment, green phosphor, or other materials can be used as luminescent material for the luminescent layer ^¬ to.

In a further embodiment, between the carrier and the heat conducting element over the entire through hole. away a gap or a cavity formed. As a result, on the one hand, the thermal conductivity between the heat-conducting element and the carrier is reduced, on the other hand, however, this allows convection of hot gas or hot air within the through-hole. Thus, a sufficient heat distribution or heat dissipation can be achieved. In particular, a higher temperature is given in the middle of the carrier than in the edge region. By means of the gap or the cavity, the temperature difference can be at least partially compensated.

A simple embodiment of the filament is achieved when the carrier is strip-shaped and the Wärmelei ^¬ tion element is cylindrical. By Zylin ^¬ the mold an approximately constant layer thickness of heat ^¬ pipe element over the length of the carrier is provided. This allows a uniform heat dissipation over the length of the carrier.

In a further embodiment, the through-hole is formed in the shape of a cylinder and has approximately a circular cross-section. Thus, the through hole can be easily manufactured. In addition, the strip-shaped carrier can thereby be arranged at approximately equal distances in the middle in the heat conduction element

For a simple contacting of the carrier, the contacts of the carrier are located in end portions of the through hole or project laterally from the heat conduction member or are arranged at least partially or completely outside the through-hole ^¬. In this way, a simple contacting of the electrical contacts of the carrier can be realized.

Use of the proposed support may be provided with a transparent housing, a lighting means, wherein the filament with the heat-conducting member in the housing is arranged at ^¬, and both electrical contacts of the carrier with the contact terminals of the transparent housing are electrically connected.

In one embodiment, the housing is hermetically sealed and is in particular filled with a gas, in particular He ^¬ lium. Using the gas can be achieved by filament improved Were ^¬ meabfuhr.

For a simple process for producing a radiation-emitting filament, a carrier with at least two

Luminescent chips provided. The carrier has an electrical contact at gegenüberlie ^¬ constricting ends. The light chips are electrically connected to the electrical contacts. Furthermore, a heat conduction member having a through hole is provided. The carrier with the light chips is inserted into the through hole of the Wärmeleitungsele ^¬ mentes and connected to the heat conduction element. The heat conduction element is formed of a material which is transparent to the electromagnetic radiation of the light-emitting chips. In addition, the heat-conducting member of a mate rial ^¬ is formed, which has a higher thermal conductivity than helium. By means of this method, a radiation-emitting filament can be provided in a simple manner, which has improved heat dissipation.

The above-described characteristics, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understood in connection with the following description of the embodiments which will be described in connection with the drawings. Show it

1 shows a first cross section through a radiation ^¬ animal filament,

FIG. 2 is a plan view of the filament of FIG. 1. FIG 3 shows a cross section through the filament of FIGS. 1 and 2,

4 shows a cross section through a further embodiment of a filament,

Fig. 5 shows a further cross section through the filament of

 4,

Fig. 6 shows a further cross section through the filament of

 Fig. 5,

Fig. 7 perspective view of a filament a heat conduction element, and

Fig. 8 is a schematic representation of a lighting means

FIG. 1 shows, in a schematic cross-sectional illustration, a filament 100 which has a carrier 120. Luminescent chips 110 are arranged on the carrier 120. On the carrier 120 electrical conductor tracks 130 are provided. Furthermore, the carrier 120 has a first electrical contact 150 and a second electrical contact 155 at opposite ends of the carrier 120. A first and a last conductor track 130 are each electrically conductively connected to the first and the second electrical contact 150, 155, respectively. In addition, the electrical conductor tracks 130 connect the light-emitting chips 110 in the form of a series connection. For this purpose, each light chip 110 has on a lower side a first and a second electrical connection 111, 112. The light-emitting chips 110 are designed to generate electromagnetic radiation, in particular visible light. For example, the light-emitting chips 110 can produce blue, red or green light. The light-emitting chips can, for example as radiation-emitting diode chips (LED) or may be formed as the laser diode chip from ^¬. Depending on the selected embodiment, the light-emitting chips may be 110 ^¬ covered with a luminescent layer 140th The luminescent layer 140 represents a conversion Layer is, and has an optically excitable lamps which emits the electromagnetic radiation of the light-emitting chips from ^¬ sorbed and with a changed wavelength. For example, the luminescent layer 140 may comprise a matrix material and a light source in the form of red or green phosphor. The illuminant may include an MDF phosphor or a KSF phosphor.

In the illustrated embodiment, the luminescent layer 140 covers both the light-emitting chips 110 and a Oberflä ^¬ surface of the substrate 120. Depending on the selected execution ^¬ can form the luminescent layer 140 may be also arranged only on the light-emitting chips 110th Instead of the light emitting layer 140 or ^¬ additionally to the light emitting layer 140, a protective layer may cover the light-emitting chips 110 and the carrier 120th In the Darge ^¬ presented embodiment, the luminescent layer 140 is disposed only on the top 160 of the carrier 120 and the light-emitting chips 110th Depending on the selected embodiment, the entire carrier 120, ie also side surfaces and a lower side of the carrier can be covered with the luminescent layer 140.

Be the light-emitting chips 110 represent radiation-emitting semiconductor chip ^¬. The carrier 120 may be made of a rigid or a flexible substrate, in particular a carrier plate ^¬ formed. The carrier 120 may also consist of silicon carbide or sapphire. The carrier 120 has the shape of a strip. In this case, a height of the strip in ei ^¬ Z direction is significantly smaller than a length of the strip in an X direction. The light-emitting chips 110 may be formed beispielswei ^¬ se as LEDs or laser diodes. In the illustrated embodiment, the light-emitting chips 110 have electrical connections 111, 112 on the underside. From ^¬ pending chosen by the embodiment, the look electrical connections may be provided at the top of the light-emitting chips 110 also laterally and / or. In addition, for an electrical contacting of the printed conductors 130 instead of a direct contact between the electrical terminals 111, 112 of the light emitting circuit 110 also be provided bonding wires. The carrier 120 extends in the longitudinal direction along an x-axis. A height or thickness of the carrier 120 is arranged along a z-axis.

FIG. 2 shows a top view of the arrangement of FIG. 1, wherein a width of the carrier 120 is arranged in a y-axis. The width of the carrier is greater than the height of Trä ^¬ gers. In the selected representation, the luminescent layer 140 is shown transparent. As already stated, the luminescent layer 140 can also be dispensed with. In addition, from ^¬ pending chosen by the embodiment may have only two light-emitting chips 110, a carrier 120, which are in series or parallel to ^¬ sorted. Depending on the chosen embodiment, a carrier 120 have more than two light-emitting chips 110 ^¬ serially and / or in parallel electrically conductively connected to the electrical contacts 150, 155th The arrangement of the light-emitting chips 110 can be correspondingly designed differently. Furthermore, the conductor tracks 130 can also have correspondingly required shapes for the electrical connection of the light-emitting chips 110. The electrical contacts 150, 155 are formed, for example, of metal. The x-axis, the z-axis and the y-axis form an orthogonal coordinate system.

Fig. 3 shows a schematic cross-section through the filament 100 of FIGS. 1 and 2, in the z-y plane through a

Luminescent chip 110. It can be clearly seen that the light chip 110 and a top 160 of the carrier 120 with the

Luminescent layer 140 are covered.

FIG. 4 shows a cross-section in a zx-plane through a further embodiment of a radiation-emitting filament 100, which is designed essentially in accordance with the embodiment of FIGS. 1 and 2. In the illustrated embodiment, however, the luminescent layer 140 is formed in such a manner that the upper side, side surfaces and also an underside of the carrier 120 are embedded in the luminescent layer 140. 5 shows a cross section in the zx plane through the filament 100 of FIG. 4. FIG. 6 shows a cross section through a luminous chip 110 of the filament 100 of FIG. 5 in the zy plane perpendicular to FIG

It can be seen that the carrier 120 and the light-emitting chip 110 are embedded in the luminescent layer 140.

FIG. 7 shows a perspective illustration of a radiation-emitting filament 100 which is arranged in a through-hole 170 of a heat-conducting element 180. The filament 100 may be formed as shown in FIGS. The through hole 170 is cylindrical in the illustrated embodiment and has a circular shape in cross section perpendicular to the longitudinal axis of the filament 100. Depending on the chosen embodiment, other cross sections and / or other shapes of the through hole 170 may be used. The through hole 170 is opened at ge ^¬ opposite side surfaces 190, 195 of the heat conduction element 180th From the opposite openings of the through hole 170, the electrical contacts 150, 155 protrude.

Depending on the selected embodiment, the end pieces of the carrier 120 from the opposite Seitenflä ^¬ surfaces 190, 195 of the heat conduction member 190 may protrude from the through-hole ^¬ 170th In addition, the electrical contacts 150, 155 may also terminate within the through-hole 170 in the end regions of the through-hole 170. Depending on the selected embodiment, the through-hole 170 may also have a larger cross-section in the end region in order to allow a simpler electrical contacting of the electrical contacts 150, 155.

In the illustrated ^{embodiment, the} heat conduction element 180 has the shape of a cylinder with the central through-hole. on the way up. Depending on the selected embodiment, the heat conduction element 180 may also have other shapes and / or cross sections. The heat conduction member is formed of egg ^¬ nem material which is transparent to the electromagnetic radiation of the light-emitting chips. Here ^¬ as glass can be example as material for the thermal conduction member 180 ver ^¬ spent. Thus, the heat conduction element can be designed as a glass ^¬ tube. Furthermore, the heat conduction ^¬ element is formed of a material having a higher thermal conductivity than helium having see. This is given for glass with a thermal conductivity of 0.8 watts per millikelvin. The thermal conductivity of helium is ei ^¬ nem range of 0.14 watts per milli-Kelvin. The cross section of the through hole is compared to

Cross-section of the carrier 120 with the light-emitting chips 110 and possibly ^¬ the luminescent layer 140 performed in such a way that is formed depending on the ^¬ selected embodiment, a gap or a cavity between the carrier 120 and the heat conduction element 180 over the entire through hole 170 , By this is meant that the gap or cavity extends over the entire length of the through hole. However, the carrier 120 can also be connected to the heat conduction element 180 at least locally or continuously over the entire length. In this way, a thermal balance within the through-hole 170 can be achieved by means of an air or gas circulation. In the gap between the carrier 120 with the light-emitting chips 110 and the possibly before ^¬ seen luminescent layer 140 may be provided air or gas. In addition, the carrier 120 may be connected using an adhesive ^¬ layer, in particular made of a transparent adhesive having the heat-conducting member 180 with the light-emitting chips 110 and possibly with the light-emitting layer 140th As an adhesive, for example, a low-viscosity silicone adhesive can be used.

The filament 100 is fixed in the through hole 170. As to ^¬ for example, heat conductive adhesive used ^¬ to the entire surface or pointwise between the carrier 120 and the inside of the heat conduction member 180 are formed. The width of the support may be selected so that we ^¬ nigstens 70% of the width of the through hole to be filled by the carrier 170th Depending on the selected embodiment, the luminescent layer or a protective layer can also rest directly on an inner wall of the through-hole 170.

Furthermore, the heat conduction element 180 may also have a rough, roughened or structured outer wall 200. Co- help the roughened and / or structured outer wall 200, the surface of the heat conduction element 180 magnification ^¬ is ßert. This improves heat transfer to the environment. In an analogous manner, an inner wall 260 of the through-hole 170 can also be roughened in order to have an enlarged surface.

FIG. 8 shows a schematic illustration of a luminous means 210 which has a transparent housing 220. The lighting means 210 is in the form of a light bulb. The housing 220 is formed of glass. The housing 220 is sealed gas ^¬ tight and has a first and a second contact terminal 230, 240. In the housing 220, two ^filaments 100 with heat conducting elements 180 are arranged. The filaments 100 with heat conducting elements 180 are formed as shown in FIG. The electrical contacts 150, 155 of the ^filaments 100 are electrically conductively connected to the first and the second contact connection 230, 240 of the luminous means 210 via wires 250. In the illustrated embodiment, the two filaments are electrically connected in series. Depending on the chosen embodiment, only one filament with a heat conduction element 180 can be arranged in the housing 220. In addition, more than two filaments 100 may be arranged with heat conducting elements 180 in the housing 220. In addition, the filaments can be connected electrically in series and / or in parallel.

Depending on the chosen embodiment, the housing 220 can be filled with air or with a gas such as helium. be filling. The arrangement of the heat conduction element 180 around the radiation-emitting filament 100 around ei ne improved heat dissipation from the filament 100 to the environment, that is, the interior of the housing 220 allows.

The invention has been further illustrated and described with reference to the preferred Ausführungsbei ^¬ games. Nevertheless, the invention is not limited to the disclosed examples. Rather, other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention.

REFERENCE LIST Filament

 light chip

 first electrical connection of the light chip second electrical connection of the light chip carrier

 conductor path

 luminous layer

 first electrical contact

 second electrical contact

 Top carrier

 Through Hole

 Heat conduction member

 first side surface

 second side surface

 outer wall

 Lamp

 casing

 first contact connection

 second contact connection

wire

Claims

PATENTA'S TEST 1. Radiation-emitting filament (100) with a carrier (120), wherein on the carrier (120) at least two light ^¬ chips (110) are arranged, wherein the carrier (120) at opposite ends in each case an electrical contact (150, 155) wherein the luminescent chips (110) are electrically conductively connected to the contacts (150, 155), wherein the carrier (120) with the luminescent chips (110) is arranged in a through hole (170) of a heat conduction element (180), wherein the heat conduction element (180) is formed of a material that is transparent to the electromagnetic radiation of the luminescent chips (110), wherein the carrier (120) is attached to the heat conduction member (180), and wherein the heat conduction member (180) is formed of a material has a higher thermal conductivity than helium. 2. filament (100) according to claim 1, wherein the heat conduction ^¬ element (180) is formed of glass. 3. filament (100) according to any one of the preceding claims, wherein the luminous chips (110) and / or the carrier (120) are covered with a luminescent layer (140), wherein the luminous ^¬ layer (140) is formed to a wavelength of electromagnetic radiation of the light chips (110) to move. 4. filament (100) according to any one of the preceding claims, wherein a gap between the carrier (120) and the heat ^¬ line element (180) over the entire through hole (170) is formed. 5. filament (100) according to any one of the preceding claims, wherein the carrier (120) is strip-shaped, and wherein the heat conducting element (180) is cylindrical. 6. filament (100) according to any one of the preceding claims, wherein the through hole (170) is cylindrical in shape and has approximately a circular shape in cross section. 7. filament (100) according to any one of the preceding claims, wherein the contacts (150, 155) of the carrier (120) in ^¬ opposite end portions of the through hole (170) are arranged or laterally from the heat conduction element (180) sticking out or outside the through hole (170) are arranged. 8. filament (100) according to one of the preceding claims, wherein the strip-shaped carrier (120) has a width ^¬ which corresponds to at most 50% of a length of the carrier (120), and wherein the width of the carrier (120) we ^¬ nigstens 70% corresponds to a width of the through hole (170). 9. illuminant (210) with a transparent housing (220), with electrical contact terminals (230, 240), wherein a filament (100) according to one of the preceding claims in the housing (220) is arranged, and wherein the electrical contacts (150 , 155) of the carrier (120) to the contact terminals (230, 240) are electrically connected. 10. Illuminant (210) according to claim 9, wherein the housing  (220) is hermetically sealed, and wherein the housing (220) is filled in particular with helium. A method of making a radiation-emitting filament (100), wherein a carrier (120) is provided with at least two luminescent chips (110), wherein the carrier (120) has an electrical contact (150, 155) at opposite ends, respectively Luminescent chips (110) are electrically conductively connected to the electrical contacts (150, 155), wherein a heat ^¬ line element (180) with a through hole (170) Be is provided, wherein the carrier (120) with the light ^¬ chips (110) in the through hole (170) of the Wärmelei ^¬ tion element (180) is introduced, wherein the carrier (120) and with the heat conduction element (180) is connected, the heat-conducting member (180) is formed of a Ma ^¬ material which has been transparent to the electromag ^¬-magnetic radiation of the light-emitting chips (110), wherein the heat conduction member (180) is formed of a material having a higher thermal conductivity than helium. 12. The method of claim 11, wherein the heat conduction member (180) is formed of glass. 13. The method according to any one of claims 11 or 12, wherein a gap between the carrier (120) and the ^{Wärmeleitungsele ¬} ment (180) over an entire length of the through hole (170) is formed. 14. A method according to any one of the preceding claims, wherein the carrier (120) is strip-shaped, and where ^¬ cylindrical out at the heat-conducting member (180) forms ^¬. 15. The method according to any one of claims 11 to 14, wherein the Carrier (12) is arranged in the through hole (170) in such a way that the contacts (150, 155) of the carrier (120) in opposite end regions of the through hole (170) are arranged or side of side surfaces (190, 195) of the heat conduction element ( 180) outstanding or outside of the through hole (170) arranged who ^¬ .