TW202420510A - Component having anchoring structure and method for producing a component having anchoring structure - Google Patents

Abstract

A component (10) is provided which comprises a carrier (1) and a housing body (2), wherein the carrier (1) comprises an electrically conductive surface (1A) and wherein the housing body (2) is electrically insulating and is mechanically fixed to the electrically conductive surface (1A) of the carrier (1). A mechanical connection between the carrier (1) and the housing body (2) is enhanced by an anchoring structure (3), wherein the anchoring structure (3) comprises metal rods (3A) penetrating into the housing body (2). The metal rods (3A) are nano-rods and/or micro-rods and are distributed meadow-like in places on the electrically conductive surface (1A) of the carrier (1). Moreover, a method for producing such a component (10) is provided.

Description

Component with anchoring structure and method for manufacturing component with anchoring structure

A component having an anchoring structure is specified. In addition, a method for manufacturing a component or a plurality of such components having an anchoring structure is provided.

A known assembly comprising a carrier and a housing formed on the carrier may exhibit insufficient mechanical stability due to a poor mechanical connection or poor adhesion between the housing and the carrier.

One object is to provide a component having an anchoring structure configured to strengthen the mechanical connection between a carrier and a housing of the component, resulting in an improved mechanical stability of the component. Another object is to provide a simplified but efficient method for manufacturing such a component or a plurality of such components.

These objects are solved by an assembly according to the independent claims and by a method described in conjunction with the independent claims. Further specific embodiments of the assembly or of the method are the subject matter of the further claims.

According to at least one specific embodiment of an assembly, the assembly includes a carrier and a housing. The carrier includes a conductive surface. The housing is electrically insulating and mechanically fixed to the conductive surface of the carrier. A mechanical connection between the carrier and the housing is reinforced by an anchoring structure. The anchoring structure includes a plurality of metal rods penetrating into the housing, wherein the metal rods are nanorods and/or microrods and are distributed like a grass field at certain locations on the conductive surface of the carrier.

Here, the conductive surface may be a top surface of a main body of the carrier, such as a surface of a lead frame or an insulating substrate having a metal layer.

According to at least one specific embodiment of the assembly, the metal rods have a lateral diameter from 30 nm to 20 μm, such as from 30 nm to 10 μm, from 30 nm to 5 μm, from 30 nm to 2 μm, from 100 nm to 10 μm, from 300 nm to 10 μm or from 500 nm to 5 μm. Here, the metal rods can have a cross-section with any geometric shape. For example, these cross-sections are circular, quasi-circular, elliptical or irregularly shaped. The metal rods can present a hollow cross-section or a filled cross-section. For example, the diameter of the metal rods is provided by the maximum lateral expansion of the corresponding metal rod. In other words, the diameter of a metal rod should be understood as the maximum lateral extension of a cross-section of the metal rod. The metal rods may be formed from metals such as copper, gold, silver, platinum, nickel or tin.

In the case of nanorods, the diameters may be from 30 nm to 1 μm, such as from 30 nm to 900 nm, from 30 nm to 600 nm, from 30 nm to 300 nm, from 30 nm to 100 nm, or from 100 nm to 1 μm, from 300 nm to 1 μm, from 500 nm to 1 μm, or from 600 nm to 1 μm. In the case of microrods, the diameters may be from 1 μm to 20 μm, from 3 μm to 20 μm, from 5 μm to 20 μm, or from 10 μm to 20 μm. All metal rods may be nanorods, microrods, or a mixture of nanorods and microrods.

A transverse direction is understood to be a direction parallel to a main extension surface of the carrier, for example parallel to the top surface of the body of the carrier. A vertical direction is understood to be a direction orthogonal to the main extension surface of the carrier and/or to the top surface of the body of the carrier. The vertical direction and the transverse direction are orthogonal to each other.

According to at least one specific embodiment of the component, the metal rods have a vertical height from 2 microns to 100 microns, for example, from 2 microns to 80 microns, from 2 microns to 50 microns, from 2 microns to 20 microns, from 2 microns to 10 microns, from 2 microns to 5 microns, or from 5 microns to 100 microns, from 10 microns to 100 microns, from 20 microns to 100 microns, from 30 microns to 100 microns, from 50 microns to 100 microns, or from 60 microns to 100 microns.

All of the metal bars may have approximately the same vertical height. For example, the vertical height of any one of the individual metal bars may not differ from the average vertical height of all of the metal bars by more than 50%, 30%, 20%, 10%, 5%, or 3% of the average vertical height.

According to at least one specific embodiment of the assembly, the number of metal rods is greater than 10, 20, 30, 50, 100, 300, or greater than 1000. Depending on the size of the diameters of the metal rods, the lateral distance between adjacent metal rods can be greater than or less than the average diameter of the metal rods, such as 0.1 to 10 times the average diameter, 0.7 to 7 times the average diameter, 0.5 to 5 times the average diameter, 0.3 to 3 times the average diameter, or 0.2 to 2 times the average diameter.

According to at least one specific embodiment of the component, the housing is a molded body. A molded body is understood to mean an electrically insulating body that can be formed by a packaging process. A packaging process is generally understood to mean a process of shaping a molding compound according to a specified shape and, if necessary, selectively curing it under the action of temperature or pressure. In particular, the term "packaging process" includes at least molding, injection molding, vacuum injection molding, film-assisted molding, transfer molding and compression molding. The housing can be made of an electrically insulating molding material, such as a plastic, a castable polymer such as epoxy or silicone. For example, the housing is formed by compression molding or by film-assisted molding. The molding material may contain filler particles, such as silicon dioxide particles and titania particles or carbon black.

According to at least one specific embodiment of the assembly, the carrier is a lead frame made of a conductive material, such as copper or a copper alloy. The conductive surface can be a surface of the lead frame, such as a top surface of the lead frame.

The lead frame may include a first region and a second region separated from the first region. The first region and the second region may be laterally surrounded by the housing and thus mechanically connected to each other with the housing. In a vertical direction, the first region and/or the second region may extend through the housing at least at certain locations. The first region and the second region may be assigned to different polarities of the component. The first region and the second region may be configured to electrically contact the component to an external voltage source.

According to at least one specific embodiment of the assembly, the carrier comprises an insulating substrate. The insulating substrate may include a plurality of through holes and/or current spreading structures. The carrier may further include a metal layer, wherein the conductive surface of the carrier is a surface of the metal layer. For example, the carrier comprises a ceramic substrate having the metal layer formed thereon. The metal layer may be structured and include a plurality of sub-regions that may be separated in space. The carrier may also be a printed circuit board.

According to at least one specific embodiment of the assembly, the assembly further comprises a first semiconductor chip. The first semiconductor chip may be arranged on a first subregion of the conductive surface, wherein the first subregion is not covered by the metal rods. For example, the first semiconductor chip is configured to emit electromagnetic radiation. The assembly may comprise a plurality of first semiconductor chips.

The assembly may further include a second semiconductor chip, wherein the second semiconductor chip is disposed on another area of the conductive surface not covered by the metal rods. The second semiconductor chip may be electrically connected to the first semiconductor chip in an anti-parallel manner. The second semiconductor chip may be a protection diode. The second semiconductor chip may be embedded in the housing. For example, the first semiconductor chip is not covered by the housing.

According to at least one specific embodiment of the assembly, the anchoring structure further comprises a plurality of ties. For example, the ties are formed as lateral parts of the carrier. The ties may have the minimum vertical thickness of the carrier. For example, the ties surround the housing in a manner on a plurality of side surfaces of the assembly, the ties being flush with the housing.

According to at least one specific embodiment of the assembly, the anchoring structure further comprises a plurality of step-shaped elements. The step-shaped elements may be formed on a plurality of side surfaces of the carrier. The housing may be anchored to the step-shaped elements. In this way, the housing may be prevented from being separated from the carrier in a vertical direction. In a plan view of the top surface of the carrier, the step-shaped elements may be formed as an inverted staircase and may not be visible.

According to at least one specific embodiment of the component, the component further includes a packaging layer. For example, the packaging layer is formed in an opening of the shell. The packaging layer can be anchored to the metal rods. The packaging layer can be transparent or include a plurality of fillers and/or can have the shape of a lens. The packaging layer may include a conversion element or be the conversion element. For example, a plurality of phosphor particles are embedded in the material of the packaging layer. In a top view, the packaging layer may at least partially or completely cover the first semiconductor chip. The packaging layer may be formed by the so-called "exposed die molding" concept.

According to one embodiment of a method for manufacturing an assembly having a carrier and a shell, the method includes a step of forming an anchoring structure on a conductive surface of the carrier, wherein the anchoring structure includes a plurality of metal rods as nanorods and/or microrods. The metal rods are distributed like grass at certain locations on the conductive surface of the carrier. The method further includes a step of forming the shell at at least certain locations on the carrier. The shell is made of an electrically insulating material and mechanically fixed to the conductive surface of the carrier so that the metal rods penetrate or protrude into the shell to strengthen the mechanical connection between the carrier and the shell.

According to at least one specific embodiment of the method, the step of forming the anchoring structure on the conductive surface of the carrier is performed by using a template, which includes a plurality of through holes as nanoholes and/or microholes. The template can be arranged or formed on the conductive surface of the carrier, and the metal rods are formed in the through holes. For example, the template is prefabricated and arranged on the conductive surface of the carrier. The metal rods can be formed in the through holes of the template.

According to at least one specific embodiment of the method, forming the anchoring structure on the conductive surface of the carrier includes the step of forming a template having a plurality of through holes as nanoholes and/or microholes on the conductive surface by using a photolithography process. In this case, the template can be formed directly on the carrier. The metal rods can be formed in the through holes of the template. The template can be made of a photostructurable material, for example, a photolithographically passive or reactive lacquer.

According to at least one specific embodiment of the method, the step of forming the shell is subsequent to the step of forming the anchor structure. For example, the step of forming the shell is performed by a molding or casting process. Here, a molding material can be applied to certain locations on the metal rods so that the metal rods penetrate into the shell before the molding material solidifies.

The method is particularly suitable for producing a component described in the present case. Features described in connection with the component may therefore also be applied to the method, and vice versa.

Identical, equivalent or equivalently acting elements are indicated in the drawings by the same reference symbols. The drawings are diagrammatic and therefore not necessarily true to scale. Relatively small elements and in particular layer thicknesses may be shown quite exaggerated for better illustration.

FIG. 1A shows an example of an assembly 10 in cross-section. Assembly 10 includes a carrier 1 having a top surface 1A. Top surface 1A is a conductive surface 1A. For example, carrier 1 includes a body formed of a conductive material. Top surface 1A may be a top surface of the body. A metal layer (e.g., a nickel-palladium-gold layer) may also be formed on the body. In this case, top surface 1A as a conductive surface may be formed at least at some locations on a surface of such a metal layer.

The main body may be a lead frame 6. The lead frame 6 or the carrier 1 may include a first sub-region 61 and a second sub-region 62, the second sub-region being separated from the first sub-region 61 by an intermediate region 60 in a transverse direction.

A plurality of metal rods 3A are formed at certain locations on the top surface 1A, such as at certain locations on the surfaces of both the first region 61 and the second region 62. For example, the metal rods 3A are nanorods and/or microrods, which are distributed like a lawn on the top surface 1A of the carrier 1. The metal rods 3A may cover at least 5% or 10% and at most 80% of the total area of the top surface 1A, such as 10% to 70%, 10% to 60%, 10% to 50%, 10% to 40%, or 10% to 30% of the total area of the top surface 1A. The metal rods 3A may form or may be part of an anchoring structure, which is configured to strengthen the mechanical connection between the carrier 1 and a housing 2 of the assembly 10.

As shown in FIG. 1A , the housing 2 is disposed at least at some positions on the top surface 1A of the carrier 1 , wherein the metal rod 3A penetrates into the housing 2 . Therefore, the housing 2 is anchored to the metal rod 3A, so that the adhesive strength between the housing 2 and the carrier 1 is enhanced.

The housing 2 is electrically insulating. The housing 2 may be a molded body. A molded body may be understood to mean a body formed by a casting or molding process. Thus, the housing 2 may be formed by a molding material. Typically, the adhesion of molding compounds to metal surfaces, such as the surface of a nickel-palladium layer or a copper layer or other metal surfaces, is quite low. For example, a smooth and flat metal layer does not provide sufficient mechanical anchoring. It is recommended to apply metal rods 3A to the top surface 1A of the carrier 1 so that the carrier 1 can be anchored to the housing 2. As shown in FIG. 1A in a top view, the housing 2 may completely cover the metal rods 3A. However, some of the metal rods 3A are not covered by the housing 2.

For example, the top surface 1A of the carrier 1 is not completely covered by the metal rod 3A. Sub-regions of the top surface 1A not covered by the metal rod 3A can be configured to receive one or more semiconductor chips 4 and/or electrical connections such as bonding wires 7. As shown in Figure 1A, the assembly 10 includes at least one first optoelectronic semiconductor chip 41, which can be an optoelectronic semiconductor chip 41. The first optoelectronic semiconductor chip 41 can be configured to emit or detect electromagnetic radiation, such as electromagnetic radiation in the visible, ultraviolet or infrared regions of the spectrum during operation of the assembly 10. Therefore, the assembly 10 can be configured to emit or detect light in the visible, ultraviolet or infrared regions of the spectrum.

As shown in Fig. 1A, the assembly 10 has a phosphor layer 81 disposed or fixed on the first semiconductor chip 41. The phosphor layer 81 may include a radiation transmissive material having a plurality of fluorescent particles embedded therein for light conversion, wherein the fluorescent particles may be configured to convert ultraviolet radiation and/or electromagnetic radiation in the blue spectral range into electromagnetic radiation in the green, yellow, red or infrared spectral range.

For example, the phosphor layer 81 does not completely cover a top surface of the first semiconductor chip 41. The area not covered by the phosphor layer 81 can be configured to receive an electrical connection, such as a first bonding wire 71. The phosphor layer 81 may completely cover the entire optical interface of the first semiconductor chip 41. The optical interface can be defined by a top surface of the first semiconductor chip 41, through which electromagnetic radiation is emitted during operation of the first semiconductor chip 41. The first bonding wire 71 can electrically connect the first semiconductor chip 41 to the second secondary region 62 of the lead frame 6 or the carrier 1. The first semiconductor chip 41 is arranged on the first secondary region 61 of the lead frame 6 or the carrier 1, and its entire bottom side can be electrically connected to the first secondary region 61. Therefore, the first semiconductor chip 41 can be electrically connected to the first and second regions 61 and 62 of the carrier 1 or the lead frame 6. The component 10 has a bottom surface 10B, which can be formed at certain positions on the bottom surfaces of the first and second regions 61 and 62. Therefore, the component 10 is electrically connected to an external power supply via its bottom surface 10B. The bottom surface 10B may be formed at certain positions on the surface of the housing 2.

A side surface 1S of the carrier 1 may not be covered by the housing 2 and may therefore be accessible from the outside. Therefore, the side surface 1S of the carrier 1 may also be used to electrically connect the assembly 10 to an external power supply. For example, the first and/or second regions 61, 62 of the carrier 1 have an external side surface 1S which is not covered by the material of the housing 2 at least in certain locations or completely. In a transverse direction, the first and/or second regions 61, 62 may be flush with the housing 2. However, the middle region 60 may be filled with the material of the housing 2 so that the inner surface of the first and/or second regions 61, 62 may be covered by the material of the housing 2. The housing 2 may be formed as a single piece and may therefore be connected. In a plan view of the top surface 1A, the housing 2 may completely cover the second subsection 62 and partially cover the first subsection 61.

The component 10 has an out-coupling surface, which may be formed on an outer surface of the phosphor layer 81. The outer surface of the phosphor layer 81 may be exposed. For example, depending on the encapsulation process, the out-coupling surface of the phosphor layer 81 is exposed by removing the encapsulation material after the molding process or by performing the molding process, so that the outer surface of the phosphor layer 81 is not covered by the molding material during the encapsulation process or the molding process.

The assembly 10 has a top surface 10A. The top surface 10A is formed at some position on the surface of the housing 2. In this case, the housing 2 can be touched from the outside on the top surface 10A of the assembly 10. The top surface 10A may include a surface of the phosphor layer 81. The surface of the phosphor layer 81 and the surface of the housing 2 may be flush with each other at a vertical position, as shown in FIG. 1A.

The exemplary embodiment of an assembly 10 shown in FIG. 1B is substantially identical to the exemplary embodiment of the assembly 10 shown in FIG. 1A when shown in a top view. A deviation from FIG. 1A is that the side surface 1S of the carrier 1 may be covered by the material of the housing 2. In the transverse direction, the housing 2 may completely surround the carrier 1. In this case, the first and second regions 61, 62 of the carrier 1 are surrounded by the housing 2. The side surface 10S of the assembly 10 may be provided completely or largely by the side surface of the housing 2. A deviation from this is that the side surface 10S of the assembly 10 may also include the surface of the grating 3B shown in, for example, FIGS. 5B and 6B and/or the stepped element 3C.

In FIG. 1B , the distribution of the metal rods 3A on the top surface 1A of the carrier 1 is illustrated. The areas of the top surface 1A that are completely or at least in certain locations covered by the metal rods 3A are framed or surrounded by the dotted lines in FIG. 1B . These areas of the top surface 1A can be covered by the housing 2 . However, the covering is shown in a perspective manner in FIG. 1B , so that the distribution of the metal rods 3A can be seen. As shown in FIG. 1A and FIG. 1B , the metal rods 3A form a grass-like area on the top surface 1A.

As shown in FIG. 1B , the first sub-region 61 includes a mounting surface that is part of the top surface 1A and is not covered by the metal rod 3A. In the lateral direction, the mounting surface can be completely surrounded by the metal rod 3A. The semiconductor chip 4 or 41 is arranged on the mounting surface. The second sub-region 62 includes a contact surface that is part of the top surface 1A and is not covered by the metal rod 3A. In the lateral direction, the contact surface can be partially or completely surrounded by the metal rod 3A. The contact surface is configured to receive a first bonding wire 71 that spans the middle region 60.

As shown in FIG. 1A and FIG. 1B , the housing 2 may be adjacent to all side surfaces of the semiconductor chip 4. The first bonding wire 71 may be completely embedded in the housing 2. The first subsection 61 and/or the second subsection 62, and thus the carrier 1, may have straight and substantially smooth side surfaces 1S. The metal rod 3A forms an anchoring structure 3, which strengthens the mechanical connection between the carrier 1 and the housing 2.

Additional anchoring elements such as tie grids 3B and/or step-shaped elements 3C may not be necessary to achieve a component 10 with high mechanical stability. In particular in the case of small components 10, such as small light-emitting diode (LED) packages, there is no or hardly any space available for forming additional anchoring elements, and the metal rod 3A may form the only anchoring element of the anchoring structure 3. In this case, the anchoring structure 3 may dispense with additional anchoring elements such as step-shaped elements 3C and/or tie grids 3B, as shown in, for example, FIGS. 5B and 6B.

Thus, in the case of mechanical stresses during operation or already during manufacturing, such as when the separation or singulation of the component 10 is carried out (e.g. by sawing), it is possible to avoid cracks or fissures appearing in the component 10 or, in extreme cases, parts of the carrier 1 (e.g. the lead frame 6) being pulled out of the housing 2. When there is no tie grid 3B, the singulation of the component 10 can be carried out in a simplified and robust manner, since the singulation will only be carried out within the housing 2.

The exemplary embodiment of an assembly 10 shown in FIG. 2A is substantially identical to the exemplary embodiment of the assembly 10 shown in FIG. 1A . The deviation from FIG. 1A is that, according to FIG. 2A , the housing 2 includes an opening or a cavity 20 in which the first semiconductor chip 41 is disposed. The cavity 20 has a plurality of inclined inner walls that are separated from the first semiconductor chip 41 and from the first bonding wire 71. In this case, the first bonding wire 71 is not embedded in the housing 2.

A bottom surface of the cavity 20 may include the surface of the housing 2, the surface of the first region 61 and the second region 62 of the main body of the carrier 1 or the lead frame 6. The bottom surface of the cavity 20 may eliminate the metal rod 3A, or may be provided with the metal rod 3A at least in some positions. The cavity 20 may be filled with a packaging material such as a light-transmitting material (e.g., filled with an electrically insulating and radiation-transmissive packaging layer 82 as shown in FIG. 4 or FIG. 6A). The metal rod 3A may also provide an additional mechanical connection between the carrier 1 and the packaging layer 82.

Further deviating from FIG. 1A , similar to FIG. 1B , in the lateral direction, the carrier 1 can be completely surrounded by the housing 2 . This is also clearly shown in FIG. 2B , where an exemplary embodiment of an assembly 10 shown in FIG. 2B is substantially identical to the exemplary embodiment of the assembly 10 shown in FIG. 1B . The assembly 10 shown in FIG. 2B can be identical to the assembly 10 shown in FIG. 2A .

As shown in FIG. 2B , the assembly 10 further includes a second semiconductor chip 42, wherein the second semiconductor chip 42 is disposed on the second subregion 62 of the carrier 1. For example, the second semiconductor chip 42 is electrically connected to the first semiconductor chip 41 in an antiparallel manner. The second semiconductor chip 42 may be a protection diode, such as an electrostatic discharge (ESD) chip. The second semiconductor chip 42 may be electrically connected to the second subregion 62 via its bottom side and to the first subregion 61 via a second bonding wire 72 across the middle region 60. As indicated in FIG. 2B , the second semiconductor chip 42 may be embedded in the housing 2. The cavity 20 is indicated in FIG. 2B by an area marked by a solid line frame. Thus, the second semiconductor chip 42 may be located outside the cavity 20. As shown in FIG. 1B , in FIG. 2B , the area surrounded by the dotted line is the area of the metal rod 3A that can be covered by the housing 2 and anchored to the housing 2 .

The exemplary embodiment of an assembly 10 shown in FIG. 3 is substantially identical to the exemplary embodiment of an assembly 10 shown in FIG. 1A . A deviation from FIG. 1A is that, according to FIG. 3 , the main body of the carrier 1 may be formed of an electrically insulating material. The main body of the carrier 1 may be formed as a single piece and thus connected. For example, the main body of the carrier 1 is an insulating substrate 5. The insulating substrate 5 may be a ceramic substrate, a printed circuit board (PCB) or the like.

The carrier 1 comprises a metal layer 50. The metal layer 50 may be a metal layer made of or comprising at least one of copper, gold, silver, platinum, nickel and tin, or a nickel-palladium-gold layer. The metal layer 50 has a vertical thickness which is significantly smaller than a vertical thickness of the insulating substrate 5, for example, at least 3, 5, 10, 20 or at least 50 times smaller. The metal layer 50 may be divided into a plurality of spatially separated sub-regions 51 and 52, wherein the sub-regions 51 and 52 may be configured to receive the semiconductor chip 4 and/or electrical connections such as bonding wires 7. The metal layer 50 may also include a plurality of strip-shaped regions formed as conductor tracks for electrically connecting, for example, different sub-regions 51 and 52 of the same polarity.

The top surface 1A as a conductive surface 1A of the carrier 1 may be formed on a surface of the metal layer 50. The metal rods 3A may be formed on a plurality of predetermined regions on the surface of the metal layer 50, for example, by growth.

The exemplary embodiment of an assembly 10 shown in FIG4 is substantially consistent with the exemplary embodiment of the assembly 10 shown in FIG2A. In contrast, according to FIG4, similar to FIG3, the carrier 1 may include an insulating substrate 5 and a metal layer 50.

In addition, the cavity 20 is filled with a packaging layer 82, which is anchored to a metal rod 3A formed on a bottom surface of the cavity 20. Here, the metal rod 3A penetrates into the packaging layer 82 to strengthen the mechanical connection between the carrier 1 and the packaging layer 82. The packaging layer 82 can partially or completely fill the cavity. The top surface 10A of the component 10 can be partially formed on a top surface of the packaging layer 82 and partially formed on a top surface of the shell 2. The top surface of the packaging layer 82 can be a flat surface as shown in Figure 4, or it can be concavely or convexly curved, such as the dome shape shown in Figure 6A. The packaging layer 82 can have the appearance of a lens. The bonding wires 7, such as the first bonding wire 71, can be completely embedded in the packaging layer 82.

The exemplary embodiment of an assembly 10 shown in Fig. 5A is substantially identical to the exemplary embodiment of the assembly 10 shown in Fig. 1A. In addition to the metal rod 3A shown in Fig. 1A, according to Fig. 5A, the anchoring structure 3 may further include a grating 3B and/or a stepped element 3C.

In the present case, a tie 3B can be understood as a transverse portion of the carrier 1, which can extend in a transverse direction to a side surface 10S of the component 10. Therefore, the tie 3B is visible at the side surface 10S of the component 10. At the side surface 10S of the component 10, the tie 3B can have singulation marks. This is due to the tie 3B being separated (for example cut or sawed during the singulation process), such as shown in FIG. 7D. In a plan view of the top surface 1A of the carrier 1, the tie 3B is formed as a strip extending transversely from the first or second area 61, 62 of the carrier 1. The grating 3B typically has a smaller transverse length or width than the total length or total width of the first or second region 61, 62, for example, at least 3, 4, 5, 6 or 10 times smaller.

In the present case, a trapezoidal element 3C can be understood as an overcut (German: undercut) of the carrier 1. At the location of the trapezoidal element 3C, the carrier 1 has a reduced vertical height, for example a reduction of the total thickness of the carrier 1 from 20% to 80%, from 20% to 70%, from 20% to 60%, from 20% to 50% or from 20% to 40%. Unlike the grating 3B, the trapezoidal element 3C is generally not visible in a plan view of the top surface 1A of the carrier 1, since it is located below the top surface 1A of the carrier 1. Below the top surface 1A of the carrier 1, the trapezoidal element 3C can extend approximately along the entire transverse length or width of the first region 61 or the second region 62. The step-shaped element 3C may be located beside the middle area 60 between the first sub-area 61 and the second sub-area 62. The step-shaped element 3C may also be located beside the side surface 1S of the carrier 1. If the carrier 1 is surrounded by the housing 2, the step-shaped element 3C is usually not visible at the side surface 10S of the assembly 10.

The exemplary embodiment of an assembly 10 shown in FIG5B is substantially identical to the exemplary embodiment of the assembly 10 shown in FIG5A when shown in a top view. As shown in FIG5B , each of the first and second regions 61, 62 of the carrier 1 may include a plurality of ties 3B, here for example six and four ties 3B, respectively. (Multiple) step-shaped elements 3C below the top surface 1A may be present, but are not explicitly shown in FIG5B . Typically, the step-shaped elements 3C have a larger lateral width or a larger lateral length than the ties 3B. The step-shaped elements 3C may have a larger vertical thickness than the ties 3B. The tie gate 3B is configured to connect different first sub-regions 61 and/or different second sub-regions 62 of different carriers 1 of different components 10 during manufacturing. Since the tie gate 3B is cut during the singulation process of the component 10, the tie gate 3B is generally designed to have a small size.

3 and 4, the tie gate 3B may be formed in a primary region of the metal layer 50. The step-shaped element 3C may be formed by structuring the insulating substrate 5, for example, by locally reducing the vertical thickness of the insulating substrate 5.

The exemplary embodiment of an assembly 10 shown in FIG. 6A is substantially identical to the exemplary embodiment of the assembly 10 shown in FIG. 2A . In addition to the metal rod 3A, the anchoring structure 3 may further include a grating 3B and/or a stepped element 3C according to FIG. 6A and similar to FIG. 5A . Furthermore, in FIG. 6A , it is clearly shown that the cavity 20 is completely filled with the encapsulation layer 82, which is dome-shaped and has the appearance of a lens. Furthermore, it is clearly shown that the metal rod 3A formed on the bottom surface of the cavity 20 penetrates into the encapsulation layer 82.

The exemplary embodiment of an assembly 10 shown in FIG6B is substantially identical to the exemplary embodiment of the assembly 10 shown in FIG2B . In addition to the metal rod 3A, the anchoring structure 3 may further include a grating 3B and/or a stepped element 3C according to FIG6B and similar to FIG5B . The assembly shown in a top view in FIG6B may be the assembly 10 shown in a cross-sectional view in FIG6A .

7A to 7D show some method steps for manufacturing a plurality of components 10. The components 10 manufactured by the method can be any of the components 10 described in the present case. For the sake of clarity, the connection with FIGS. 7A to 7D only explicitly shows the manufacture of components 10 such as those described in FIGS. 3, 5A and 5B.

According to FIG. 7A , a carrier complex 1V is provided. The carrier complex 1V includes a plurality of carriers 1. Each carrier 1 may include at least one first region 51 or 61, and at least one second region 52 or 62. A first region 51 or 61 may be mechanically connected to an adjacent second region 52 or 62, or to another first region 51 or 61, by means of a tie 3B. A second region 52 or 62 may be mechanically connected to an adjacent first region 51 or 61, or to another second region 52 or 62, by means of a tie 3B. The first region 51 or 61 and the second region 52 or 62 may be part of a lead frame 6 or a metal layer 50 formed on, for example, an insulating substrate 5.

A template 9 is arranged or formed on the carrier complex 1V. The template 9 includes a plurality of through holes 9H which are nanopores and/or micropores. The distribution of the through holes 9H can be adapted to the size and geometry of the first region 51 or 61, the second region 52 or 62 and/or the grating 3B shown in FIG. 7B . The template 9 may include a plurality of first regions 91 and second regions 92 without through holes 9H. Each of the first region 91 and/or the second region 92 of the template 9 may be laterally surrounded by the through holes 9H. Other regions of the template 9 which do not cover the first region 51 or 61, the second region 52 or 62 and/or the grating 3B of the carrier complex 1V in the top view may also be free of through holes 9H.

The template 9 can be formed from an electrically insulating material. The template 9 including the through holes 9H can be prefabricated or directly formed on the carrier composite 1V, such as the top surface 1A of the carrier 1, for example using a photolithography method. In the case of the photolithography method, the template 9 can be made of a photostructurable material, for example, a photolithographically passive or reactive lacquer.

The metal rod 3A can be formed in and/or through the through-hole 9H. The formation of the metal rod 3A can be accomplished in many ways, such as by using the capillary action of the through-hole 9H, which acts as a pore/channel and allows a solution of a dissolved material to enter the pores after the solvent evaporates slowly. It is also possible to use electrodeposition, in which the top surface 1A of the carrier 1 is used as an electrode, such as a cathode for electroplating. Alternatively, electroless plating can be used, in which a catalyst is applied to the wall of the through-hole 9H, which promotes metal deposition on the activated pores of the template 9. The micron or nano material manufactured in this way is in the shape of a wire or a small tube. Therefore, generally, the metal rod 3A can be a wire or a small tube.

As shown in FIG7C , the metal rod 3A is formed in a predetermined position on the carrier composite 1V or on the carrier 1. The step of forming the shell 2 may be subsequent to the step of forming the metal rod 3A or the step of forming the anchor structure 3. For example, the template 9 is removed before the shell 2 is formed.

Semiconductor chips 4, such as the first semiconductor chip 41 and/or the second semiconductor chip 42, may be arranged at predetermined positions of the first and/or second regions 51 or 61 and/or 52 or 62 of the carrier 1. In the lateral direction, each of the semiconductor chips 4 may be partially or completely surrounded by the metal rod 3A.

Furthermore, before or during the formation of the housing 2 , the semiconductor chip 4 may be electrically connected to another first or second subregion 51 , 61 , 52 or 62 of the corresponding carrier 1 by forming bonding wires 7 (eg, by forming first bonding wires 71 and/or second bonding wires 72 ).

The step of forming the shell 2 can be performed by a molding or casting process, in which a molding material is applied to at least some positions of the metal rod 3A so that the metal rod 3A penetrates into the shell 2 before the molding material solidifies. Therefore, the shell 2 is formed on the carrier composite 1V or at least some positions on the carrier 1. Here, the shell 2 is made of an electrically insulating material and is mechanically fixed to the top surface 1A as the conductive surface 1A of the carrier 1 so that the metal rod 3A penetrates into the shell 2 to strengthen the mechanical connection between the carrier 1 and the shell 2.

According to FIG. 7D , the component 10 can be singulated along a plurality of singulation lines 9L. In the top view, the singulation lines 9L intersect the grating 3B. Thus, the grating 3B can be cut. The side surface 10S of the component 10 or the side surface 1S of the carrier 1 is formed along the singulation lines 9L. Thus, the grating 3B can be visible at the side surface 1S or 10S shown in, for example, FIGS. 5A to 6B . On the side surface 1S or 10S, the grating 3B can have singulation marks, for example mechanical marks from a sawing process.

As described in the present case, the metal rod 3A can be used to anchor the housing 2 and/or the encapsulation layer 82 to the carrier 1, in particular to a metallic top surface 1A of the carrier 1. Both the layout and the material of the top surface 1A can thus be mostly freely selected, and the effective surface area for adhesion is increased. Possible materials for the metal rod 3A can be copper, gold, silver, platinum, nickel, tin, etc. In the case of the housing 2 being an epoxy molding compound (EMC), copper, for example, is a very suitable material for the metal rod 3A due to its high adhesion properties.

The geometry and placement of the metal rods 3A can be defined in many ways, for example using a prefabricated template 9, or can be defined on the carrier 1 by a photoprocess. The distribution of the metal rods 3A can thus be defined very accurately and finely. Furthermore, the distribution of the metal rods 3A can be predefined in a simplified manner if the photolithographic resolution of the sub-areas with metal rods 3A is combined with thin films, and the ion track etching channels of these thin films determine the diameter and density of the metal rods 3A.

The use of metal rod technology when anchoring a housing, which may be an injection molded body, to a substrate or a lead frame is advantageous in many ways.

For example, since the molding surface remains unoccupied during the molding process (e.g. during injection molding), the position of the metal rod 3A will be clearly defined so that even when possible cavities are molded, there will be no conflict with the molding process.

The mounting area for attaching the semiconductor chips and for wire bonding can be kept small. The risk that the semiconductor chip 4 and/or the bonding wire 7 may become detached when large thermomechanical stresses occur can be significantly reduced.

The size of the metal rods 3A and/or the spacing or density of the metal rods 3A can be adapted to the size of the filling particles, which can be embedded in the shell 2 and/or in the packaging layer 82. For example, the lateral distance between the metal rods 3A can be larger or smaller than the size or diameter of the filling particles.

By using the metal rod 3A, the need for CTE (coefficient of thermal expansion) matching of the housing 2 and/or the encapsulation layer 82 to the carrier 1 can be reduced. Therefore, it is possible to use transparent or light-transmitting materials for the housing 2 and/or for the encapsulation layer 82.

For example, in the case where the housing 2 is a molded body, the mold fit of the molded body around the main body of the carrier 1 (e.g., the lead frame 6) can become tighter, which will reduce or simplify the so-called deburring process during cavity molding. Problems such as general leakage of coating materials and leakage of welding flux or similar low-viscosity materials (e.g., silicone leakage) due to the gap between the lead frame 6 and the molded body will be eliminated or at least significantly reduced. During the molding process, for example, the deburring process becomes necessary due to leakage of pressurized liquid molding compound between the housing 2 in a liquid aggregate state and the top surface 1A.

As mentioned above, the metal rod 3A is also used not only for the shell 2 which can be formed by injection molding but also for effective anchoring of one of the other materials, and can therefore be used to anchor a packaging layer 82 in the form of a transparent package or lens (such as a silicone lens which can be manufactured by compression molding or compounding).

In addition to the mechanical connection, the metal rods 3A also improve thermal coupling and thus help to dissipate heat losses more efficiently. Without the presence of the metal rods 3A, the CTE transition between the epoxy molding compound (EMC) and the carrier 1 (e.g. from the epoxy molding compound to copper) can be very sharp. By molding in the metal rods 3A as microwires and/or nanowires, the CTE transition will become smooth, thereby significantly improving the thermo-mechanical reliability.

Thus, the encapsulated metal rod 3A reduces the CTE of the nanowire and/or nanowire EMC compound. The EMC material itself no longer needs to be precisely matched to the carrier 1 with respect to CTE, even without the use of inorganic fillers, such as silica particles. This allows more fillable EMC to be processed with less inorganic filler. The housing 2 or the cured EMC is thus more ductile, which further increases the stability of the assembly 10. The encapsulated metal rod 3A also provides stress absorption and increases the mechanical stability of the assembly 10.

The component 10 may be an LED package having a housing 2, for example, as an injection molded body. Thus, the component 10 may be a pre-molded package, a quad flat no-lead (QFN) package or a film-assisted molding (FAM) package, having a good anchoring of the housing on a carrier 1, which comprises, for example, a lead frame, a ceramic substrate or a PCB. If the material of the housing 2 (e.g. epoxy or silicone or a mixture) has a rather poor adhesion on metal surfaces, additional mechanical anchoring is also possible, for example by using further anchoring structures, such as overcuts in the form of step elements 3C or tie bars 3B in the carrier 1. However, particularly in the case of small components 10 such as small LED packages, if no space or only little space is available for this purpose, the use of metal rods 3A alone may be sufficient to achieve a highly stable component 10 .

This application claims priority to German Patent Application No. 102022117093.4, the disclosure of which is incorporated herein by reference.

The present invention is not limited to the exemplary embodiments by the invention description made with reference to the exemplary embodiments. Instead, the present invention includes any novel features and any combination of features, especially including any combination of features in the claims, even if the feature or the combination itself is not explicitly indicated in the patent claims or the exemplary embodiments.

10: Component 10A: Top surface of component 10B: Bottom surface of component 10S: Side surface of component 1: Carrier 1A: Top surface of carrier/conductive surface of carrier 1S: Side surface of carrier 1V: Carrier composite 2: Housing 20: Hole of housing 3: Anchor structure 3A: Metal rod 3B: Tie bar 3C: Step element 4: Semiconductor chip 41: First semiconductor chip 42: Second semiconductor chip 5: Insulating substrate 50: Metal layer 51: First region of metal layer/carrier 52: Second region of metal layer/carrier 6: Lead frame 61: First region of lead frame/carrier 62: Second region of lead frame/carrier 60: Middle region 7: Bonding wire 71: First bonding wire 72: Second bonding wire 81: Phosphor layer 82: Packaging layer 9: Template 91: First region of template 92: Second region of template 9H: Through hole of template 9L: Singularization line

Further specific embodiments and further developments of the component or the method will become apparent from the specific embodiments described below in conjunction with FIGS. 1A, 1B, 2A, 2B, 3, 4, 5A, 5B, 6A, 6B, 7A, 7B, 7C and 7D. FIGS. 1A and 1B show schematic diagrams of examples of a component in cross-section and in top view. FIGS. 2A, 2B, 3, 4, 5A, 5B, 6A and 6B show schematic diagrams of further examples of a component in cross-section and in top view. FIGS. 7A, 7B, 7C and 7D show schematic diagrams of some method steps for manufacturing at least one component or a plurality of such components.

1: Carrier

1A: Top surface of carrier/conductive surface of carrier

1S: Side surface of the carrier

2: Shell

3: Anchor structure

3A: Metal rod

4: Semiconductor chip

6: Conductor frame

7: Joining wires

10: Components

10A: Top surface of component

10B: Bottom surface of the component

10S: Side surface of component

41: First semiconductor chip

60: Middle area

61: The first area of the wire frame/carrier

62: Second area of the wire frame/carrier

71: First bonding wire

81: Phosphor layer

Claims (16)

A component (10) comprising a carrier (1) and a shell (2), wherein the carrier (1) comprises a conductive surface (1A), the shell (2) is electrically insulated and mechanically fixed to the conductive surface (1A) of the carrier (1), the mechanical connection between the carrier (1) and the shell (2) is reinforced by an anchoring structure (3), and the anchoring structure (3) comprises a plurality of metal rods (3A) penetrating into the shell (2), wherein the metal rods (3A) are nanorods and/or microrods and are distributed like grass at certain positions on the conductive surface (1A) of the carrier (1). An assembly (10) as claimed in claim 1, wherein the metal rods (3A) have a lateral diameter ranging from 30 nanometers to 20 micrometers. An assembly (10) as claimed in any one of claims 1 to 2, wherein the metal rods (3A) have a vertical height ranging from 2 microns to 100 microns. An assembly (10) as claimed in any one of claims 1 to 3, wherein the shell (2) is a molded body. A component (10) as claimed in any one of claims 1 to 4, wherein the carrier (1) is a lead frame (6) made of a conductive material, and the conductive surface (1A) is a surface of the lead frame (6). As a component (10) of claim 5, wherein the lead frame (6) includes a first region (61) and a second region (62) separated from the first region (61), the first region (61) and the second region (62) are laterally surrounded by the housing (2) and are thus mechanically connected to the housing (2), and along a vertical direction, the first region (61) and/or the second region (62) extend through the housing (2) at least at certain locations. A component (10) as claimed in any one of claims 1 to 4, wherein the carrier (1) comprises an insulating substrate (5) and a metal layer, wherein the conductive surface (1A) is a surface of the metal layer. A component (10) as claimed in any one of claims 1 to 7, further comprising a first semiconductor chip (4, 41), wherein the first semiconductor chip (4, 41) is arranged on a first area of the conductive surface (1A), and the first area is not covered by the metal rods (3A). The component (10) of claim 8 further comprises a second semiconductor chip (4, 42), wherein the second semiconductor chip (4, 42) is arranged on another area of the conductive surface (1A) not covered by the metal rods (3A), and wherein the second semiconductor chip (4, 42) is electrically connected to the first semiconductor chip (4, 41) in an anti-parallel manner. An assembly (10) as claimed in any one of claims 1 to 9, wherein the anchoring structure (3) further comprises a plurality of gratings (3B), which are transverse parts of the carrier (1), have the minimum vertical thickness of the carrier (1) and are surrounded by the shell (2), so that on a plurality of side surfaces (10S) of the assembly (10), the gratings are flush with the shell (2). An assembly (10) as claimed in any one of claims 1 to 10, wherein the anchoring structure (3) further includes a plurality of stepped elements (3, 3C) formed on a plurality of side surfaces (1S) of the carrier (1), wherein the housing (2) is anchored to the stepped elements (3, 3C) and prevented from being separated from the carrier (1) in a vertical direction. An assembly (10) as claimed in any one of claims 1 to 11, further comprising a packaging layer (82), wherein the packaging layer (82) is formed in an opening of the housing (2) and anchored to the metal rods (3A). A method for manufacturing an assembly (10) having a carrier (1) and a shell (2), comprising: forming an anchoring structure (3) on a conductive surface (1A) of the carrier (1), wherein the anchoring structure (3) comprises a plurality of metal rods (3A) as nanorods and/or microrods, the metal rods being distributed like grass at certain positions on the conductive surface (1A) of the carrier (1); and forming the shell (2) at least at certain positions on the carrier (1), wherein the shell (2) is made of an electrically insulating material and mechanically fixed to the conductive surface (1A) of the carrier (1), so that the metal rods (3A) penetrate into the shell (2) to strengthen the mechanical connection between the carrier (1) and the shell (2). A method as claimed in claim 13, wherein the step of forming an anchoring structure (3) on the conductive surface (1A) of the carrier (1) is performed by using a template (9), which includes a plurality of through holes (9H) serving as nanoholes and/or microholes, wherein the template (9) is prefabricated and arranged on the conductive surface (1A) of the carrier (1), and wherein the metal rods (3A) are formed in the through holes (9H). The method of claim 13, wherein the step of forming an anchoring structure (3) on a conductive surface (1A) of a carrier (1) comprises: forming a template (9) on the conductive surface (1A) by using a photolithography process, the template having a plurality of through holes (9H) as nanoholes and/or microholes; and forming the metal rods (3A) in the through holes (9H). A method as claimed in any one of claims 13 to 15, wherein the step of forming the shell (2) is subsequent to the step of forming the anchor structure (3), and the step of forming the shell (2) is performed by a molding process or a casting process, wherein a molding material is applied to certain positions on the metal rods (3A) so that the metal rods (3A) penetrate into the shell (2) before the molding material solidifies.