DE102017115780A1 - Light-emitting diode component, light-emitting diode arrangement and method for producing a light-emitting diode component - Google Patents

Abstract

A light-emitting diode component (1) has a carrier (2) and a light-emitting diode (4) which is arranged on a first outer side (3) of the carrier (2), wherein the carrier (2) has a plurality of layers (5), and has a first and a second external contact (10, 11), wherein the light-emitting diode component (1) has a mounting side (14) which is designed to be arranged on a printed circuit board (18), the first outside (3) not being parallel to the mounting side (14 ) runs.

Description

The present invention relates to a light-emitting diode component having a light-emitting diode (LED) and a carrier, on which the light-emitting diode is arranged. The carrier is designed as a multilayer carrier.

For backlighting of screens, such as TV screens, LEDs are mounted in a so-called "Edge LED Display" side of a screen. For this purpose, LEDs are conventionally used on a Fr4 carrier or plastic carrier, in particular a PLCC (Plastic Leaded Chip Carrier), with a 90 ° rotated optical axis and an external TVS diode as ESD protection. The light output is u.a. in such solutions u.a. strongly limited due to the low thermal conductivity of the carrier. In addition, shading may occur due to the external diode. Other LED concepts with integrated ESD protection allow the light-emitting diode to be soldered on only parallel to the surface of the carrier.

It is an object of the present invention to provide a light emitting diode device having improved characteristics.

According to a first aspect of the present invention, a light-emitting diode component comprising a carrier and a light-emitting diode is specified. The carrier has a stack with several layers. In particular, these are ceramic layers. On a first outer side of the carrier, a light-emitting diode is arranged.

A functional element, in particular an ESD protection element, can be integrated in the stack. The functional element is formed for example by one or more electrode layers and ceramic layers. The functional element has, for example, a first and a second electrode layer, which are electrically contacted from the outside, and a third electrode layer, which is designed as a floating electrode and is not contacted from the outside. By integrating the functional element in the carrier, a high degree of miniaturization can be achieved.

The light-emitting diode component has a mounting side, which is designed for arrangement on a printed circuit board. Thus, the mounting side is that outside, which faces the circuit board during assembly of the LED component and can also rest on the circuit board. The first outside is not arranged parallel to the mounting side. In particular, the first outer side may be arranged at a 90 ° angle to the mounting side. The mounting side, for example, adjoins the first outer side.

In this way, an assembly of the light-emitting diode component is made possible such that the first outer side, on which the LED is arranged, is arranged at an angle to the upper side of the printed circuit board. Thus, the optical axis of the LED is rotated to the circuit board, so that the light-emitting diode component is particularly well suited for use in an Edge LED display.

The light-emitting diode component has a first and a second external contact. The external contacts are designed for making electrical contact with the light-emitting diode component, for example for contacting a functional element integrated in the carrier and / or for contacting the light-emitting diode. The external contacts are arranged for example on opposite outer sides of the carrier. A first external contact is arranged, for example, on a second outer side and a second external contact on a third outer side, wherein the second and third outer side adjoin the first outer side. For example, the mounting side also adjoins the second and third outer sides. The external contacts may be formed as metallizations.

The external contacts are in particular designed such that the light-emitting diode component can be fixed on a circuit board by soldering. In particular, the external contacts are designed for surface mounting (SMD mounting).

The external contacts extend for example at least up to the mounting side. Thus, an electrical contact to the circuit board can be reliably ensured by soldering. The solder material can be applied laterally to the outer contacts, in particular in the lower edge region of the external contacts.

The external contacts may extend at least to the first outside. This allows a reliable electrical connection of the LED through the external contacts. For example, the first outer contact completely covers the second outer side, and the second outer contact completely covers the third outer side.

In one embodiment, the external contacts in cross-section in a plane parallel to the first outer side each have a concave shape. Thus, the external contacts - and for example, the second and third outer side - have an inwardly curved shape. The inwardly curved shape can be formed in particular in the case of an inner contour, ie, a contour line adjoining the ceramic, of the respective outer contact. The inwardly curved shape may also be present at an outer contour of the external contacts. The external contacts can both in terms of their Inner contour and with respect to its outer contour have a concave shape.

In one embodiment, the outer contacts in cross-section in a plane parallel to the first outer side of the geometry of a circular arc. In particular, the inner contour of the respective outer contact is formed in the form of a circular arc. The external contacts can also each have the shape of a circular section. In this case, the inner contour in the form of a circular arc, wherein the material of the external contacts partially or completely fills the arc.

The external contacts are formed, for example, from a severed through-connection. In the manufacture of the light-emitting diode component, plated-through holes are formed through the layers, for example, in a multilayer substrate. When singulating the substrate is severed at the site of the via. The geometry of the via and the location where the cut is made determine the shape of the external contacts. For example, obtained in through holes with round cross-section, the external contacts a circular arc-shaped contour.

For contacting the light emitting diode contact structures may be formed on the first outer side. The contact structures are formed for example as metallizations. The contact structures may be directly connected to the external contacts. For example, a first contact structure and a second contact structure are arranged on the first outer side. The contact structures are connected, for example, in each case in an edge region of the first outer side with an external contact.

In one embodiment, the contact structures each have a contact region for contacting the LED and a connection region which leads to an external contact. The contact area is, for example, wider than the connection area. The width is the extension perpendicular to the mounting side. In addition, the contact structures may have a connection region which is directly connected to the external contact. The connection region is, for example, wider than the connection region and thus establishes a reliable electrical contact with the external contact.

According to a further aspect, a light-emitting diode arrangement comprising a printed circuit board and a light-emitting diode component arranged thereon is specified. The light-emitting diode component may in particular be designed as described above. The light-emitting diode component has a multilayer carrier in which a functional element is integrated. On a first outer side of the carrier, a light-emitting diode is arranged. The light-emitting diode component is arranged on the printed circuit board such that the first outer side is not arranged parallel to an upper side of the printed circuit board.

The light-emitting diode component is soldered to the printed circuit board, for example. The solder material is arranged, for example, laterally by external contacts of the light-emitting diode component.

According to a further aspect, a method for producing a light-emitting diode component is specified. In particular, the method is suitable for the production of the light-emitting diode component described above.

In this case, a substrate comprising a plurality of layers is provided. The layers are, for example, green films, in particular ceramic green films. At least one functional element, for example an ESD protective element, can be integrated in the substrate. For this purpose, some layers may be printed with electrode material.

In the substrate openings are introduced. In particular, the openings can pass completely vertically through the substrate. The openings have, for example, in cross-section a round shape or an elongated shape. The openings are beispielswese introduced by means of a laser in the substrate.

The substrate is sintered so that all layers are sintered together. The sintering process can also take place before the openings are introduced or in a later step.

Subsequently, metallizations for forming contact structures for contacting a light-emitting diode are applied to a first outer side of the substrate, for example, printed in a screen printing process. The metallizations are baked, for example. The baking can also be done together with the sintering of the substrate.

Optionally, a passivation can be applied. The passivation serves, for example, as a solder stop and is applied in particular at the locations of the first outer side which are not intended to be in direct electrical contact with the light-emitting diode. For example, it is a glass passivation.

In the openings, a conductive material is introduced to form vias. In particular, the walls of the openings are coated with the material. For example, the material is electrodeposited in an electrochemical process (English: plating). The material may be arranged only in a wall region of the openings or completely fill the openings.

The substrate is finally singulated, whereby the plated-through holes are severed on singulation. Thus, external contacts are formed from the plated-through holes, which are arranged on the outer sides of the isolated carrier.

Before separating, light-emitting diodes can be applied to the contact structures, in particular soldered. Optionally, lens and / or conversion structures can be formed on the light-emitting diodes.

The light-emitting diode component produced in this way can finally be fastened to a printed circuit board, in particular soldered.

In the present disclosure, several aspects of an invention are described. All the properties disclosed in relation to the component, the component arrangement or the method are also disclosed correspondingly with respect to the other aspect, even if the respective property is not explicitly mentioned in the context of the other aspect.

Furthermore, the description of the subject matter specified here is not limited to the individual specific embodiments. Rather, the features of the individual embodiments - as far as technically feasible - can be combined.

The objects described here are explained in more detail below with reference to schematic exemplary embodiments.

• 1 eine Ausführungsform eines Leuchtdiodenbauteils im Schnittbild,
• 2 die Ausführungsform des Leuchtdiodenbauteils aus 1 in seitlicher Ansicht, angeordnet auf einer Leiterplatte,
• 3 ein Schritt eines Verfahrens zur Herstellung eines Leuchtdiodenbauteils,
• 4 ein Schritt eines weiteren Verfahrens zur Herstellung eines Leuchtdiodenbauteils.

Show it:

• 1 an embodiment of a light-emitting diode component in a sectional view,
• 2 the embodiment of the light emitting diode component 1 in a lateral view, arranged on a printed circuit board,
• 3 a step of a method of manufacturing a light-emitting diode device,
• 4 a step of a further method for producing a light-emitting diode component.

Preferably, like reference numerals refer to functionally or structurally corresponding parts of the various embodiments in the following figures.

1 shows a light-emitting diode component 1 comprising a carrier 2 on the outside 3 a light emitting diode (LED) 4 , in particular in the form of a light-emitting diode chip, is arranged.

The light-emitting diode component 1 is particularly suitable for use in an "Edge LED Display", in which the LED 4 is arranged laterally on a display. In this structure, it is advantageous if the main emission or optical axis 19 the LED 4 horizontally with respect to a top 32 the circuit board is aligned. The optical axis 19 forms for example with a normal vector of the top 32 an angle of 90 °.

The carrier 2 is formed in multilayer construction and has a plurality of dielectric layers 5 on. The layers 5 For example, have a ceramic material such as ZnO-Bi, ZnO-Pr, Al2O3 or AlN. In particular, ZnO-Bi-Sb can be used as the ceramic material. By using suitable ceramic materials, a high thermal conductivity can be achieved.

In the carrier 2 is a functional element 6 , in particular an ESD protection element integrated. The functional element 6 is made of electrode layers 7 . 8th . 9 and ceramic layers 5 educated. The layers 5 . 7 . 8th . 9 of the carrier 2 , In particular, the layers of the functional element 6 , are sintered together. For example, the functional element 6 a first and a second electrode layer 7 . 8th on, which are arranged on the same level. The first electrode layer 7 is with a first external contact 10 and the second electrode layer 8th with a second external contact 11 electrically connected. A third electrode layer 9 is designed as a floating electrode and thus electrically connected to any external contact. The electrode layers 7 . 8th . 9 contain, for example, silver or consist of silver.

The external contacts 10 . 11 are on opposite second and third outsides 12 . 13 arranged and for electrical connection to a printed circuit board, in particular with a board (English printed circuit board, PCB) formed. The carrier 2 comes with a mounting side 14 , in particular a fourth outer side, arranged on the circuit board, wherein the mounting side 14 not parallel to the first outside 3 is arranged. In particular, the mounting side 14 at an angle of 90 ° to the first outside 3 be arranged.

The external contacts 10 . 11 extend to the first outside 3 , In particular, the external contacts 10 . 11 in the area of the edge of the first outside 3 with first and second contact structures 15 . 16 directly connected. The LED 4 is on the contact structures 15 . 16 soldered. The external contacts 10 . 11 are thus for electrical contacting of the LED 4 and the functional element 6 educated.

Between the contact structures 15 . 16 and on further areas of the first outside 3 can be a passivation 17 , For example, a glass passivation be arranged.

2 shows the light emitting diode component 1 out 1 in a side, rotated view, wherein the light emitting diode 4 here is directed to the viewer. The light-emitting diode component 1 is on a circuit board 18 arranged. Thus, in the present case, also a light-emitting diode arrangement 20 shown. The circuit board 18 is strip-shaped, but may also have a different geometry depending on the application.

The light-emitting diode component 1 is with its mounting side 14 on the circuit board 18 arranged. In particular, the light-emitting diode component is 1 with the circuit board 18 soldered and thus mechanically and electrically to the circuit board 18 connected. A first solder joint 21 ranges from the first external contact 10 to the circuit board 18 and a second solder joint 22 ranges from the second external contact 11 to the circuit board 18 , The solder joints 21 . 22 are each formed by solder material, the side of the external contacts 10 . 11 is arranged. The solder material is at least at the lower edge regions of the second and third outer sides 12 . 13 arranged. Thus, the light emitting diode component 1 on the circuit board 18 placed on and then connected by lateral application of solder material.

The external contacts 10 . 11 For example, each in a plan view from above on the LED or in a sectional image in a plane parallel to the first outer side 3 a concave shape, for example, the shape of a circular arc. In particular, have the inner contours 30 the shape of circular arcs. The concave shape can also be seen in the outer contours 31 be educated. This depends on the degree of filling with the material of the external contacts 10 . 11 from. Thus, the external contacts 10 . 11 Visible from the outside in a concave shape, ie inwardly curved shape, be formed. The outer contours 31 may alternatively be designed plan.

The contact structures 15 . 16 are each formed strip-shaped. The contact structures 15 . 16 are in the range of edges of the carrier 2 with the external contacts 10 . 11 directly connected. The contact structures 15 . 16 are narrower than the first side surface 3 so they from the mounting side 14 and the circuit board 18 are spaced.

3 shows a method step in the manufacture of a light-emitting diode component, for example of the light-emitting diode component 1 out 1 , In particular, a substrate 100 to see before a separation, with a view of the first outside 3 ,

To produce the substrate, ceramic green sheets are used to form the ceramic layers 5 provided. Some green sheets are made with electrode pastes to form the electrode layers 7 . 8th . 9 for the functional element 6 printed. The green sheets are stacked, laminated and pressed together.

Subsequently, openings are made 23 for the formation of external contacts 10 . 11 introduced into the layer stack. For example, the openings 23 introduced by means of a laser.

The openings 23 pass completely through the layer stack. For example, have the openings 23 circular cross sections. The openings 23 can also have a different geometry, such as in 4 shown.

Subsequently, the substrate becomes 100 decarburized and sintered. Thus, all layers are 5 . 7 . 8th . 9 sintered together.

On the sintered multilayer substrate 100 become metallizations 24 . 25 for the formation of the contact structures 15 . 16 applied, for example, printed in a screen printing process, and baked. The metallizations 24 . 25 each extend to the edge of an opening 23 ,

For example, the metallizations have 24 . 25 - and thus also the contact structures 15 . 16 - a wide contact area 26 on, on which the light-emitting diode 4 is arranged, and a narrow connection area 27 on that between the wide contact area 26 and the opening 23 or later the external contact 10 . 11 is arranged.

On the side of the metallizations 24 . 25 , the associated opening 23 turned away, are the metallizations 24 . 25 spaced from each other and there is a non-printed area of the top ceramic layer 5 , There is an optional passivation 17 , For example, a glass passivation, applied. The passivation 17 can be applied in a screen printing process and then baked. The passivation 17 acts as a solder stop while soldering the LED 4 , The passivation 17 can also apply to other areas of the contact structure 15 . 16 , in particular on the connection areas 27 to be applied.

After that, the openings 23 with an electrically conductive material 33 , For example, provided in the form of multiple layers. For example, a layer sequence of Ag, Ni, Au is applied. In this way, a via 28 (English: plated through hole) formed. The via 28 has, for example, a diameter of 300 μm.

This in 3 shown substrate 100 is shown in a status after this step. The substrate 100 has dimensions width x length of 101.6 mm x 101.6 mm, for example. The total thickness of the ceramic is 0.3 mm, for example.

The vias 28 are still in this stage of the process each with two contact structures 15 . 16 electrically connected. In a later process step, the composite 100 isolated, as indicated by the dashed lines.

Before singulating, the LEDs become 4 in the form of LED chips, each on two metallizations 24 . 25 or contact structures 15 . 16 attached, in particular soldered. Optionally, a lens may be applied, for example a silicone lens. Furthermore, optionally a phosphorus conversion layer can be applied.

After that, the substrate becomes 100 isolated, for example by sawing.

The separation takes place in such a way that the width b a carrier 2 not larger than the width of a via 28 is. This ensures that the external contacts 10 . 11 up to the edges of the first outside 3 rich, so that the production of an electrical contact with the circuit board is guaranteed. Furthermore, it is ensured that the external contacts 10 . 11 to the mounting side 14 range, so that a reliable electrical connection is guaranteed.

For example, an isolated carrier 2 a width b of 300 μm. The length 1 is for example 1800 microns.

The separation is done by a via 28 through, leaving a through-hole 28 two external contacts 10 . 11 be formed. When singling can be in the middle of the feedthrough 28 Material, for example, 100 microns material to be removed. Are the vias 28 not completely with electrically conductive material 33 filled, resulting in a concave shape of the external contacts 10 . 11 , in particular a circular arc-shaped contour.

For example, from a substrate 100 by separating 10,000 light emitting diode components 1 receive.

A light-emitting diode component 1 is then on a circuit board 18 attached. Here are SMD solder contacts from the isolated vias 28 available, so that the light emitting diode array 20 out 2 is obtained.

The order of steps of the method may vary. For example, the openings 23 before or after the sintering process in the substrate 100 be introduced. Also the metallizations 24 . 25 for the formation of the contact structures 15 . 16 can be applied before or after the sintering process.

4 shows a substrate 100 before singling accordingly 3 , here are the openings 23 or vias 28 for the formation of external contacts 10 . 11 and the metallizations 24 . 25 for the formation of the contact structures 15 . 16 have a different geometry.

The cutting lines for singulation of the substrate 100 are shown in dashed lines.

The openings 23 are designed as slots. In particular, the width of the openings 23 greater than the length of the openings.

Furthermore, the metallizations 24 . 25 each wide contact areas 26 for contacting an LED 4 , a narrow connection area 27 as a connecting bridge and a wide connection area 29 for electrical connection with the via 28 or the resulting external contacts 10 . 11 on.

The shape of the metallizations 24 . 25 and the shape of the openings 23 of the 3 and 4 can also be combined with each other.

LIST OF REFERENCE NUMBERS

1

LED assembly

2

carrier

3

first outside

4

led

5

layer

6

functional element

7

first electrode layer

8th

second electrode layer

9

third electrode layer

10

first external contact

11

second external contact

12

second outside

13

third outside

14

mounting side

15

first contact structure

16

second contact structure

17

passivation

18

circuit board

19

optical axis

20

LED array

21

first solder joint

22

second solder joint

23

opening

24

first metallization

25

second metallization

26

contact area

27

2ereich

28

via

29

terminal area

30

inner contour

31

outer contour

32

top

33

electrically conductive material

100

substratum

b

Width of the carrier

l

Length of the carrier

Claims (15)

A light-emitting diode component comprising a support (2) and a light-emitting diode (4) arranged on a first outer side (3) of the support (2), the support (2) comprising a plurality of layers (5), and having first and second External contact (10, 11), wherein the light-emitting diode component (1) has a mounting side (14) which is designed for mounting on a printed circuit board (18), wherein the first outer side (3) is not parallel to the mounting side (14). Light-emitting diode component after Claim 1 , wherein in the carrier (2) a functional element (6) is integrated and wherein the external contacts (10, 11) for contacting the functional element (6) are formed. Light-emitting diode component according to one of the preceding claims, wherein the first outer contact (10) on a second outer side (12) and the second outer contact (11) on a third outer side (13) is arranged, wherein the second and third outer side (12, 13) adjoin the first outer side (3). Light-emitting diode component according to one of the preceding claims, in which the outer contacts (10, 11) each extend at least as far as the mounting side (14) and to the first outer side (3). The light-emitting diode component according to one of the preceding claims, wherein the first external contact (10) completely covers the second outside (12) and the second external contact (11) completely covers the third outside (13). Light-emitting diode component according to one of the preceding claims, in which the external contacts (10, 11) each have a concave shape in cross-section in a plane parallel to the first outside (3). Light-emitting diode component according to one of the preceding claims, wherein the outer contacts (10, 11) in cross-section in a plane parallel to the first outer side (3) have the geometry of a circular arc or a circular section. Light-emitting diode component according to one of the preceding claims, in which the external contacts (10, 11) are formed from a severed plated-through hole (28). Light-emitting diode component according to one of the preceding claims, comprising a first contact structure (15) and a second contact structure (15) for contacting the light emitting diode (4), wherein the contact structures (15, 16) on the first outer side (3) are arranged and wherein the contact structures (15, 16) in each case in an edge region of the first outer side (3) with one of the external contacts 10, 11) are connected. Light-emitting diode component according to one of the preceding claims, in which the contact structures (15, 16) each have a contact region (26) for contacting the light-emitting diode (4) and a connection region (27) leading to the external contact (10, 11), wherein the contact region (26) is wider than the connection area (27). Light-emitting diode component after Claim 9 in which the contact structures (15, 16) each have a connection region (29) which is connected directly to one of the external contacts (10, 11), wherein the connection region (29) is wider than the connection region (27). A light-emitting diode arrangement comprising a light-emitting diode component (1) according to one of the preceding claims and a printed circuit board (18) on which the light-emitting diode component (1) is arranged, wherein the first outer face (3) is not parallel to an upper side (32) of the printed circuit board (18). is arranged. Light-emitting diode arrangement according to Claim 12 in which the light-emitting diode component (1) is connected to the Printed circuit board (32) is soldered, wherein the solder material is arranged laterally of the external contacts (10, 11). Method for producing a light-emitting diode component, comprising the steps: A) providing a substrate (100) comprising a plurality of layers (5), B) introducing openings (23) into the substrate (100), C) applying metallizations (24, 25) to a first outer side (3) of the substrate (100), D) introducing conductive material into the openings (23) to form plated-through holes (28), E) separating the substrate (100) and thereby severing the plated-through holes (28). Method according to Claim 14 in which the plated-through holes (28) have a round shape or an elongate shape in cross-section.

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