DE102021206773A1 - Insert for gas-tight and/or liquid-tight encapsulation with a plastic and lamp for vehicle lights with the insert - Google Patents

Abstract

An insert (3) for gas-tight and/or liquid-tight encapsulation with a plastic material comprises a base body (30, 31, 32, 33) with a surface (36) which has at least one surface section (35) to be sealed by the encapsulation, and a barrier (60, 61, 62, 62, 610) formed in the surface (36) in an edge region (34) of the surface section (35) to be sealed. This has a contact surface (66) which is aligned and inclined in relation to the surface (36) surrounding the barrier (60, 61, 62, 610) in such a way that if the plastic is overmoulded, this plastic can be cooled in a cooling process following the overmoulding forms a form fit with the surrounding surface (36) by shrinking onto the contact surface (66). A combination of the insert (3) and the encapsulation made of plastic injection molding (2) can be provided in a semiconductor vehicle lamp (1) for headlights or additional lighting for vehicles, the encapsulation being able to provide gas and/or liquid tightness and electrical insulation and the insert forms a heat sink for a substrate (10) with at least one semiconductor light source (11) arranged thereon and the substrate (10) is attached to the heat sink.

Description

technical field

Aspects of the invention presented here relate to an insert for gas-tight and/or liquid-tight encapsulation with a plastic and a combination of the insert with the corresponding plastic injection molded part. Furthermore, aspects relate to a lamp for lights of vehicles, in particular motor vehicles, comprising this combination and a method for producing the combination, in particular a semiconductor lamp.

State of the art

In the field of plastic injection molding, for example, inserts formed from a metal can be overmoulded with a plastic. The inserts can, for example, be placed or used in a mold of a clamping unit of the injection molding machine in question, after which the plastic material, which is filled as granules into the screw piston of the plasticizing unit and melted by friction heat, is poured into the mold with the respective insert under pressure, where it cools.

Such inserts can be used, for example, to reinforce a component to be made of plastic. Alternatively, the insert itself can represent the functional component, and the overmoulded plastic serves to insulate the functional insert, for example, to protect it mechanically, to reinforce it, to insulate it thermally, to give it a desired spatial shape, to mechanically connect it to other components connect, or to protect against external gases or liquids, including water (oxidation, rust), etc.

The encapsulation of inserts can offer advantages in large volumes in mass production compared to alternative manufacturing concepts or structures of the manufactured end products, since production is cost-saving.

Especially in the field of headlight bulb production, for example, there is a need to provide a high degree of tightness through the corresponding light source itself, which the light source offers when installed in the light source against moisture and dirt in the area around the light source, in order to protect its interior and in particular to protect the electronic components of the lamp from damaging effects. The same also applies to lamps for the additional lighting in the vehicle, such as brake, tail, indicator or side lights, etc. For this purpose, sealing rings can be provided which, attached to the lamp base, help to seal against a socket of the headlight.

In the case of these lighting means comprising electronic components, in particular inserts can also be installed which have an encapsulation as described above in order to fulfill one or more of the functions mentioned, such as electrical insulation, but in particular also to contribute to the impermeability to gases and liquids.

However, the well-known problem with plastic injection molding occurs that shrinkage occurs in the mold during and after the cooling process of the injection molding. In the case of plastics, shrinkage is caused by increasing crystallization or crosslinking and/or matrix formation, depending on the type of plastic (thermoplastics, duroplastics, elastomers, etc.), which causes a local increase in density. The effects of later outgassing and temperature expansion (actually: compression) may also occur. The degree of shrinkage of plastics is often much higher than that of injection molded metals, which can be 1-2% by volume, for example. Amorphous plastics such as B. Polycarbonate have a lower shrinkage of 0.6-0.8%, while semi-crystalline plastics such as polypropylene or polyethylene can be subject to shrinkage of over 2% due to increasing crystallization.

Since the amount of shrinkage is usually known or can be determined by testing prior to production, it is often possible to compensate by dimensioning the mold ahead of time so that the final product meets the desired specification. When overmoulding insert parts, this is often only possible to a limited extent, since the inserted part does not undergo the same compression as the plastic. As a rule, this will be tolerable if the surrounding plastic contracts towards the overmolded insert, for example due to different coefficients of thermal expansion (between the plastic and the material of the insert).

However, in the case of more complex structures of the insert, such as cavities that are at least filled by the encapsulation, or if larger areas of the insert protrude from the encapsulation, i.e. the encapsulation is not complete, lateral distortions or distortion of the surface can occur of the insert away. As a result, there may be a delamina tion (ie, detachment) of the plastic from an overmoulded component or insert, which can result in a void between the hardened plastic and the surface of the insert.

In experiments, the inventors found that in the case of light sources that have overmolded inserts, such empty spaces can lead to undesirable leakage paths, which can extend, for example, from an end of the light source on the light source to an end on the base, so that moisture and gases can pass through here which in turn can cause damage to the electronic components, the light sources and the headlight or auxiliary lamp components (such as the reflectors or moving parts inside).

In order to prevent such leakage paths from the outset, a subsequently applied sealing potting compound can therefore be provided at neuralgic points, which seals the leakage path or paths again. However, this requires an additional process step, as well as additional expenditure of time and money, especially in mass production. Sealing potting compounds can generally be used to connect or seal two or more components with different thermal expansion behavior and thus prevent the ingress of moisture, dust, water, etc. and thus protect components or electronic components from damage.

Presentation of Aspects of the Invention

Some of the aspects described below are therefore based on an object of providing an insert that enables gas-tight and/or liquid-tight encapsulation, in which the time and cost expenditure for further process steps following the encapsulation is reduced or saved entirely. An alternative object is to provide an insert in which the influence of delamination due to plastic shrinkage and the resulting leakage between two or more components is prevented or at least reduced. Some of the aspects described below are based in particular on the task of improving the tightness of light sources installed in headlights or in the additional lighting, etc.

One or more of these objects are achieved by an insert for gas-tight and/or liquid-tight encapsulation with a plastic having the features of patent claim 1, by a combination of the insert and a plastic injection-molded part according to claim 12, a light source comprising the combination according to claim 13 , and a method for producing the combination according to claim 14. Advantageous configurations can be found in the dependent claims.

The starting point is an insert for gas-tight and/or liquid-tight encapsulation with a plastic, which comprises a base body with a surface that has at least one surface section to be sealed by the encapsulation. The base body can be made of any material, without limitation of the generality of a metal. Here, a barrier formed in the surface in an edge area of the surface section to be sealed is provided. This barrier has a contact surface that is aligned and inclined relative to the surface surrounding the barrier in such a way that, if the plastic is overmolded, this plastic forms a positive fit with the surrounding surface by shrinking onto the contact surface in a cooling process that follows the overmolding.

In the most general case, the insert can have any three-dimensional shape and be provided for any function, as was described at the outset. The encapsulation for which the insert is intended relates to plastic injection molding, with aspects of the invention entailing complete encapsulation, i.e. complete encapsulation with plastic, not being absolutely necessary and, according to many exemplary embodiments, also not provided. According to many exemplary embodiments, however, the encapsulation forms a one-piece plastic injection molded part, which essentially accommodates the insert after injection molding.

The shrinkage of the plastic, which in particular - but not only - accompanies the cooling process, causes an increase in the density of the plastic and, as a result, a change or reduction in volume. As the injection molded plastic contracts as a result, there are forces acting therein which have an orientation relative to the surface of the insert. In the case of a surface section of the insert, within which the resulting forces are turned away from the surface, there is a risk of the formation of a void between the surface and the plastic and, as a result, depending on the three-dimensional structure of the combination of the insert and the plastic injection-molded part, the formation of a continuous leakage path that is open at its ends to the environment. With regard to the surface of the insert, this section therefore forms the surface section to be sealed. Conventionally, this would be possible, as described, by applying a sealing compound.

According to embodiments of the invention, however, a barrier is provided on the surface of the insert or the base body. The barrier may be installed in an edge area of the surface portion to be sealed. In the edge region, there is or is to be expected a force alignment that is essentially parallel to the surface of the insert part surrounding the barrier and, as a result, displacement of the plastic during shrinkage. The term "substantially parallel" also includes force orientations lying at an angle to the surface, it is sufficient that there is a force component parallel to the surface. The term "edge area" is also to be interpreted broadly: delamination can also be present or to be expected in the edge area in particular.

The barrier may be an indentation, such as a groove, in the surrounding surface, or it may be a projection formed thereon. A combination of both is also possible. The barrier comprises a contact surface which, in the event of shrinkage, exerts a force on plastic which is opposite to its force orientation and thus prevents compression at least in this direction. For this purpose, the contact surface is inclined relative to the surface surrounding the barrier, specifically in such a way that a force component of the counterforce points toward the surface or into the insert. The adjacent plastic is thus pressed against the surface during the shrinkage, i.e. it shrinks, and finally remains firmly engaged by the inclined contact surface. This engagement of the barrier with the plastic is self-locking. The pressure of the plastic on the surface creates a form fit between the insert and the plastic injection molded part. A possibly existing leak path is thus interrupted at least in the vicinity of this point on the surface.

According to a special configuration of the insert, the contact surface of the barrier forms an angle of more than 90° with the surface surrounding the barrier, so that the contact surface faces the base body. This inclination of the contact surface causes the plastic to shrink effectively onto the surface with a positive fit. An angle of 0° is defined herein as being level or flush with the surrounding surface, with the surface facing outward - away from the body. An angle of 90° means that a face is perpendicular to the surrounding surface. More than 90° means that the contact surface tilts or overhangs.

According to special developments of this embodiment, the angle of inclination of the contact surface can also be 110° or more, in special cases also 120° or more. A stronger inclination can also increase the contraction and the form fit.

According to further exemplary embodiments, the barrier can essentially completely surround the surface section to be sealed. In other words, the barrier can form a closed annular structure. This makes it possible, with particular advantage, to fix a surface section to be sealed all around by positive locking on the surface of the insert, even if there is a gap or leak path section within the section, i.e. the plastic is delaminated.

According to a further embodiment, the surface section to be sealed is a section of the surface of the base body that forms an inner surface of a cavity formed in the base body, with the edge area representing an opening or an area surrounding the opening of the cavity. As described at the outset, delamination in such cavities can be particularly problematic since the plastic injected or cast therein contracts inward, ie away from the inner surface of the cavity, so that large-area gaps can arise here. By now selecting this inner surface of the cavity as the surface section to be sealed and bringing the edge area into line with the opening of the cavity, a continuous leak path from the cavity through the opening of the cavity can advantageously at least be interrupted.

A further embodiment of the insert provides that the base body and the barrier are designed in one piece. For the formation of the barrier and its contact surface on the base body or out of the base body, high-quality tools that can also be used in mass production are available in the field of material processing - in particular metal processing - so that the additional process of adding further components is dispensed with However, the formation of the barrier and the contact surface can also be considered from the outset if possible in a corresponding molding process if this is applicable (e.g. with a base body made of steel or copper; however, the surface quality of the molded part must also be taken into account, since a certain porosity of the contact surface of the plastic would result in a possible leakage). Examples include punching tools, bending and embossing tools. Furthermore, introducing a barrier through crafting processes such as turning, milling, planing or broaching.

According to embodiments and aspects of the insert presented here, the base body can be made of a metal, in particular aluminum or copper, a ceramic or a plastic. In particularly advantageous cases, the base body can be a heat sink of a heat-generating device, preferably an electronic device. According to a very specific exemplary embodiment, in which the proposed insert has particularly advantageous properties, it can be a heat sink for a lamp, in particular a vehicle headlight lamp or a lamp for additional lighting on vehicles, such as tail lights, brake lights, turn signal lights, etc the base body develop an effective cooling function if it is made of a particularly heat-conducting material.

According to a further embodiment, the barrier of the insert can be formed by a groove formed in the surface. The inclined contact surface can form a lateral surface of the groove. With such a structure, a barrier can be realized simply by removing material from a designated design or layout. As an alternative or in addition to the groove, the barrier can also be designed as a projection which protrudes from the surface surrounding the barrier.

According to further aspects of the invention, a combination of the insert according to one or more of the configurations and embodiments described above on the one hand and a plastic injection molded part on the other hand is proposed. The plastic injection-molded part forms a positive fit with the surrounding surface due to a cooling process that follows injection molding around the insert part by shrinking onto the contact surface of the barrier of the insert part. This results in the advantages described above in each case.

According to further aspects of the invention, a semiconductor headlight lamp or a lamp for the vehicle auxiliary lighting is provided, which has the combination described above. In addition, a substrate can be provided with at least one semiconductor light source arranged thereon and with a number of electronic components providing a power supply for the at least one semiconductor light source. The insert forms in particular a heat sink, with the substrate being attached to the heat sink or being in thermally conductive connection with it, optionally also only via a thermally conductive paste or the like. The base or heat sink dissipates the heat generated during operation of the lamp. Consequently, the heat sink can simultaneously form a cooling function and also a holding function (support) for the substrate in the illuminant.

In such an application, the advantages described above with regard to the features of the insert part can be particularly effective. The heat sink and the holder formed by it can regularly form a cavity or at least partially enclosed interior space through which the electrical connections for the power supply are routed. For the purpose of their insulation and, if necessary, to create certain three-dimensional mechanical coupling structures, and also in particular to seal a front end of the illuminant with the substrate and the light sources from a rear end with the connections in a gas-tight and/or liquid-tight manner (in order to connect the electronic To protect components and the interior of the headlight from moisture and harmful gases and dirt), etc., a plastic injection molded part can also be provided, which is implemented by overmolding the insert. In this case, the plastic injection-molded part can at least partially fill out the enclosed interior space, so that there is always the risk of a leak path forming. According to the present aspects, this can at least be interrupted, if not completely avoided, by the form closure effected by means of the contact surface of the barrier.

In this context, replaceable light sources, in which LED modules (considered as electronic assemblies) are installed, represent a particularly attractive application. High-performance LEDs or even laser diodes can also be used here. The eXchangeable LED signal lamp, XLS for short, is a platform that has recently been presented and corresponds to this platform, which can also correspond to the standards provided by the International Technical Commission (IEC), under which trade name the applicant also sells corresponding products. This standard allows uniform designs with the possible variation of lighting devices, i.e. different combinations and arrangements of LEDs in the module depending on use and application. Such different applications can be, for example, daytime running lights, turn signals, brake lights or additional functions such as fog lights, high beams, etc.

Such an XLS module has, for example, a substrate with light sources arranged thereon, wherein the substrate is mounted with its rear surface on a flat front section of a heat sink section made of heat-conducting metal and shaped, for example, as a hollow cylinder. The end face forms a cooling surface of the light module mounted on the substrate. This (for example) hollow-cylindrical heat sink section forms a cavity, one (front) end of which is closed by the cooling surface, apart from openings for the passage of contact connections, and the other end of which is open and thus forms an opening to this cavity. The cylindrical holding section is formed in one piece with a section comprising cooling fins. The heat sink is overmoulded with plastic before the module is assembled, among other things to maintain the specified gas and/or moisture density, but also to give the module overall stability and to implement the platform-specific mechanical connection for installation, etc. In tests It was found that leakage paths can occur in gaps on the inner wall of the cavity between this and the overmolded plastic during cooling and outgassing after injection molding. These can now be interrupted by barriers that are formed completely or at least partially around the opening of the cavity in the cooling or base body of the insert at an edge section of the cavity, either within the cylindrical inner wall or in an adjacent flange-like one Section of the heatsink around the opening. The contact surface can be formed in a groove in the surface or in an annular projection that protrudes from the surface.

A further aspect relates to a method for producing a combination of an insert and a plastic injection molded part. The method includes: providing an insert for the gas-tight and/or liquid-tight encapsulation with a plastic, which includes a base body with a surface that has at least one surface section to be sealed by the encapsulation. It also includes forming a barrier in the surface in an edge region of the surface section to be sealed, the barrier having a contact surface which is aligned at an angle relative to the surface surrounding the barrier, overmoulding the insert in a mold of an injection molding machine with a plastic for forming a plastic injection-molded part at least partially surrounding the insert, and cooling the plastic injection-molded part so that the plastic forms a positive fit with the surrounding surface by shrinking onto the contact surface.

The same advantages result as were described with reference to the combination of an insert and a plastic injection molded part.

Further advantages, features and details of the invention result from the claims, the following description of preferred embodiments and with reference to the drawings. In the figures, the same reference symbols designate the same features and functions.

character list

• 1 eine Querschnittsansicht eines Leuchtmoduls, wobei rein beispielhaft mögliche Positionen einer Barriere an einem Einlegeteil gemäß Ausführungsbeispielen der Erfindung durch Kreise angedeutet sind;
• 2 in rein schematischer Querschnittsansicht die Entstehung eines Spalts durch Schwindung eines Kunststoffspritzgussteils in einem Abkühlprozess nach der Umspritzung eines Einlegeteils;
• 3 in ähnlicher Darstellung wie in 2 ein Einlegeteil gemäß einem ersten Ausführungsbeispiel mit einer hervorstehenden Barriere zum Anschwinden des Kunststoffs;
• 4 in Querschnittsansicht ein Einlegeteil gemäß einem zweiten Ausführungsbeispiel mit einer hervorstehenden Doppel-Barriere zum Anschwinden des Kunststoffs;
• 5 in perspektivischer Schnittansicht ein Einlegeteil gemäß einem dritten Ausführungsbeispiel mit einer als ringförmige Dichtungsnut mit innerer Anlagefläche ausgebildeten Barriere zum Anschwinden des Kunststoffs;
• 6 in vergrößerter Querschnittsansicht das Einlegeteil mit Barriere aus 5;
• 7 in perspektivischer Schnittansicht ein Einlegeteil gemäß einem vierten Ausführungsbeispiel mit einer als ringförmige Dichtungsnut mit innerer Anlagefläche ausgebildeten Barriere zum Anschwinden des Kunststoffs.

Show it:

• 1 a cross-sectional view of a light-emitting module, possible positions of a barrier on an insert according to exemplary embodiments of the invention being indicated by circles purely by way of example;
• 2 in a purely schematic cross-sectional view, the formation of a gap due to shrinkage of a plastic injection molded part in a cooling process after the encapsulation of an insert;
• 3 in a similar representation as in 2 an insert part according to a first exemplary embodiment with a protruding barrier for the shrinkage of the plastic;
• 4 in cross-sectional view, an insert part according to a second embodiment with a protruding double barrier for shrinking of the plastic;
• 5 a perspective sectional view of an insert part according to a third embodiment with a barrier designed as an annular sealing groove with an inner contact surface to prevent the plastic from shrinking;
• 6 the insert with barrier in an enlarged cross-sectional view 5 ;
• 7 a perspective sectional view of an insert according to a fourth exemplary embodiment with a barrier designed as an annular sealing groove with an inner contact surface to prevent the plastic from shrinking.

In the following description of preferred exemplary embodiments, it must be taken into account that the present disclosure of the various aspects is not limited to the details of the construction and the arrangement of the components, as they are illustrated in the following description and in the figures. The example embodiments may be practiced or carried out in various ways. It is further to be understood that the language and terminology used herein is for the purpose of specific description only and should not be construed as such in a limiting manner by those skilled in the art.

the 1 shows an overview of a lighting means or a lighting module 1 to which some exemplary embodiments of the present invention to be explained below can be applied.

As indicated by the circles, which are only schematically indicated by reference numerals 61 and 62 and in which exemplary embodiments of the barriers proposed here can be implemented, the lighting module presented here itself represents an exemplary embodiment. The lighting module 1 can meet the specifications of the XLS platform ( exchangeable LED signal lamp) correspond and suffice. Examples of such light modules - but without implementation of the embodiments shown here - can be found in the following publications, among others: US2019063706A1 , DE 102017214659 A1 , US2019110348A1 ,
DE 102017217883 A1 , DE 102017222649 A1 , DE 102018202464 A1 ,
US2019306939A1 , DE102018201228A1 , DE 102017213269 A1 ,
DE 102015206471 A1 , U.S. 2019/0063706 A1 , or US 2019/0049089 A1 , Etc.

The lighting module 1 essentially comprises a plastic injection molded part 2, which forms a housing for the lighting module, an insert 3, which forms a heat sink, an electrical connection element 4 with electrical contact pins, a sealing ring 5 and a printed circuit board 10 with light sources (e.g. LED) arranged thereon. Chips 11) and electronic components 8 that ensure the power supply of the LED chips. The plastic injection molded part 2 is formed by overmolding the insert 3 in an injection molding machine. The electrical connection element 4 itself comprises a plastic injection molded part, which in turn can be formed in one piece with the above-mentioned plastic injection molded part 2, either by injection molding in a common process or by later attachment by gluing or melting.

The plastic injection-molded part 2 absorbs the insert part 3 as a result of the overmoulding of the latter. Due to the shape of the insert 3, the plastic injection molded part 2 is divided into an inner section 21 and an outer section (reference numerals 200, 221, 24), which are formed by a number of bushings 250, which are located in corresponding through-holes 350 (cf. 6 ) of the insert are formed, are integrally connected to each other.

The plastic injection molded part 2 has a first end face with a planar end face 20 in the shape of a ring disk. Four locking elements 221, for example, are arranged along the outer circumference of the end face 20 in the shape of a ring disk, only one of which can be seen in the sectional drawing and which extends radially from an outer cylinder jacket section 200 of the Plastic injection molded part 2 protrude and form a bayonet lock with correspondingly shaped counterparts of a socket of the motor vehicle light. The undersides of the four locking elements 221 define a plane which serves as a reference plane for aligning LED chips 11 attached to the lighting module 1 with respect to the plastic injection molded part 2 with respect to an optical axis of the socket of the motor vehicle lamp into which the lighting module 1 is inserted. To activate the bayonet lock, the lighting module is inserted into the socket of the motor vehicle light and then rotated clockwise around the ring axis of the cylinder jacket section of the plastic injection-molded part 2 . One of the locking elements can have a stop (not shown) to limit the aforementioned rotational movement, which rests in the socket or mounting opening of the motor vehicle light after the bayonet locking. The bayonet lock can be implemented with a product-specific key, so that each type of light module has its own key, thus avoiding mix-ups. An elastic sealing ring 5 provides the necessary contact pressure of the light module to the socket.

On its side opposite end face 20, the plastic injection-molded part 2 has an annular flange section 24, which protrudes radially outwards from the outer lateral surface of the plastic injection-molded part 2, forms a bearing surface 240 for the sealing ring 5 and, together with the locking elements 221, forms an annular groove for accommodating the Sealing ring 5 made of silicone or rubber forms.

The heat sink or the insert 3 has a hollow-cylindrical heat sink section 31, which is arranged in the cylinder jacket section 200 of the plastic injection-molded part 2 and, on its side facing the end face 20 of the plastic injection-molded part 2, forms a flat bearing surface, i.e. a cooling surface 30 for the printed circuit board 10. The inner portion 21 of the plastic injection molding 21 is accommodated in the heat sink portion 31 . A cylinder axis of the hollow-cylindrical heat sink section 31 is identical to the axis of the cylinder jacket section 200 of the outer section of the plastic injection molded part 2. The hollow-cylindrical heat sink section 31 has a cylindrical inner surface in this specific exemplary embodiment, which forms a surface section 35 of the insert part 3 to be sealed. As indicated by the arrows in 1 is indicated, which purely schematically reflect a force alignment Fs of the shrinkage acting during the cooling process after the encapsulation, a gap S can arise between an outer surface of the inner section 21 of the plastic injection molded part 2 and the inner surface (section 35 to be sealed) of the insert 3 (see also 2 ), which can act as a leakage path for moisture or gases if, for example, it extends completely from the side of the substrate or the printed circuit board 10 via the contact bushings 39 in the end face 30, the cylindrical inner surface (see Fig. 35), an edge section 34 of the hollow-cylindrical heat sink section 31 and a disc-shaped surface 38 of the insert 3 extends to an outer edge of the inner portion 21 of the plastic injection molded part 3. As in 1 only indicated schematically by corresponding circles, according to exemplary embodiments, barriers 61 and/or 62 are formed at positions in or near this edge section 34 for this purpose, which help prevent the formation of the gap S or corresponding delamination and seal this leakage path. Corresponding exemplary embodiments are described below with reference to FIG 3 until 7 described in larger.

The cooling surface 30 is arranged perpendicularly to the cylinder axis of the hollow-cylindrical heat sink section 31 and is bonded to the printed circuit board 10 with electrically insulating, thermally conductive adhesive. The cooling surface 30 of the hollow-cylindrical heat sink section 31 has openings 39 (only one of which is shown in 6 to see), through which electrical contact pins 41, 42 of an electrical connection element 4 are passed. The electrical contact pins 41, 42 can form an interference fit with the printed circuit board 10.

The heat sink or the insert 3 also has a second, annular disk-shaped heat sink section 32 which is integrally formed on the hollow-cylindrical heat sink section 31 and whose annular axis coincides with the cylinder axis of the hollow-cylindrical heat sink section 31 . The inner section 21 of the plastic injection-molded part 2 extends around the edge section 34 of the insert part 3 and, due to the effect of the barrier 61 (if implemented), lies against the disk-shaped surface 38 of the annular disk-shaped heat sink section 32, which is on the inside in relation to the insert part 3.

Cooling ribs 33 arranged along the circumference of the second heat sink section 32 embodied in the form of an annular disk are integrally formed. The cooling ribs 33 are each separated from the second, annular disk-shaped heat sink section 32 by an angle of 90 degrees (in the 1 downwards) and each extend parallel to the ring axis of the second annular disc-shaped cooling body section 32. The cooling body 3 consists of metal, for example stainless steel sheet or aluminum, and is designed in one piece, e.g. as a deep-drawn bent part or as a stamped bent part.

The electrical connection element 4 is also designed as a plastic injection molded part and has electrical contact pins 41 , 42 which are each made of metal and are embedded in the plastic material of the electrical connection element 4 . The plastic injection molded part of the electrical connection element 4 can be formed in one piece with the plastic injection molded part 2, as shown in FIG 1 is indicated.

The electrical connection element 4 also has sections 43 , 44 designed as sockets, which extend parallel to the axis of the housing-like cylinder jacket of the plastic injection-molded part 2 . The free ends of the electrical contact pins 41, 42 respectively extend into the sections 43, 44 of the socket and there serve as electrical contacts of the lighting module and are intended for the connection of a socket-pluggable plug or connector which may be provided in the lamp socket.

After the socket and plug or connector have been assembled, this connection is sealed. The other ends of the electrical contact pins 41, 42 each protrude through the opening 39 in the cooling surface 30 of the heat sink 3 and can form a press fit with the printed circuit board 10 and are each connected to an electrical contact on the printed circuit board 10. The electrical contact pins 41, 42 are used to supply the electronic components 18 and the LED chips 11 on the printed circuit board 10 with electrical voltage.

Regarding 2 the formation of a gap due to shrinkage of a plastic injection molded part 2 in a cooling process after the encapsulation of an insert 3' is explained in a purely schematic representation. The insert 3' can, but does not have to, have the shape of the insert three from FIG. It can also be a totally different shaped part. Nevertheless, the surface section 35 to be sealed and the surface section 38 of the section 131 of the insert 3' can be shaped similarly to FIG 1 .

The insert 3' is overmoulded with plastic in a plastic injection molding process and forms a (in 2 somehow formed) inner portion 21 of a plastic injection molded part 2 from. Due to shrinkage, the plastic undergoes a change in volume (contraction), the alignment of force Fs or the movement lines of the contraction being indicated purely schematically in FIG. 2 by arrows. The actual force alignment during this process depends on many factors, including the three-dimensional shape of the large plastic injection molded part 2, the material, the cooling rate, and the heat distribution during the cooling process in the mold, etc. In the example of 1 It can be roughly estimated that the volume contraction leads to an alignment of forces in the inner section 21 to a center of the block formed by it in the hollow-cylindrical second section 31 of the insert part 3 and further around the edge section 34 in the direction of the bushings 250, which act as a fixed connection to the outer portion of the plastic injection molded part 2 can be viewed. Back to 2 A force component directed away from the surface 35 creates a gap S with a width D1 on the surface 35 and a width D2 on the surface 38 due to delamination. If this gap S continues to the edge of the plastic injection molded part 2, it is immediately apparent that a leak path can occur.

Regarding 3 Using an exemplary embodiment of an insert 3", it is explained how this leakage path can be interrupted by setting up a barrier 60 on the surface 35. The barrier 60 is designed as a projection which protrudes from the surface 36 surrounding the barrier 60. The barrier 60 has an abutment surface 66 formed at an inclined angle α to the surrounding surface 36. The angle of inclination α is approximately 140° (concavely curved overall in cross-section between 90° and 170°), ie, the abutment surface 66 faces the surface 36. In particular, the contact surface 66 is inclined against the force orientation FS of the shrinking plastic in such a way that a force component is formed parallel to the contact surface 66, which presses the plastic that is shrinking as a result against the surface 36. This creates a form fit between the resulting plastic injection molded part 2 and the barrier 60 or the insert 3" causes and the leakage path or gap S closed.

Regarding 4 another embodiment will be explained. the inside 4 illustrated edge portion 34 of the insert 3 may be the same as in 1 be depicted. But it can also be one of 1 act completely different insert 3. The force alignments are omitted in this example for simplicity. In this exemplary embodiment, two barriers 62 are provided which are arranged one behind the other in the inner surface 36 (which is also cylindrical here, for example) and have essentially the same shape. They can extend annularly on the cylindrical inner surface around a cylinder axis. The respective contact surfaces 66 here have an even greater curvature, with at least one section of the contact surfaces 66 having an inclination such that the plastic is pressed towards the inner surface 36 during shrinkage. Establishing two barriers instead of just one improves the effect of the form fit. Applied to the light module of 1 the barriers 62 are arranged in the edge section 34 on the cylindrical inner surface of the hollow-cylindrical section 31 of the heat sink or insert 3 and thus form a form fit in the section 35 to be sealed 4 Also shown are portions 36a, 36b of the inner cylindrical surface 36 which are opposed to an in 4 section shown above are offset to the right (radially outward in the cylinder). This is due to the fact that during the production of the barriers 62, the material from the 4 The underlying wall section (sections 36a, 36b) can be used by scraping and deforming the scraped material, thereby slightly increasing the diameter below the barriers 62.

With reference to the 5 and 6 is another embodiment, this time with specific reference to the insert 3 of 1 shown. Shown here is only the base body or the heat sink of the insert 3 in a section, with reference to FIG 1 illustrated upside down. The end face 30 can be seen (purely schematically without openings) with the opposite inner disk surface 37, the hollow-cylindrical section 31 with the section 35 to be sealed, and the annular disk-shaped section 32 with the disk-shaped surface 38 and the holes 350 formed therein.

Here, too, a barrier 61 is formed in the edge section 34, which, however, extends in the disc-shaped surface 38 (and not in the inner surface of the section 35 to be sealed) circumferentially along the edge section 34, ie forms a closed ring. Unlike in the 3 and 4 the barrier is designed here as a depression or groove. In 6 an enlarged cross-sectional profile of barrier 61 is shown. The barrier 61 is essentially formed by the groove 67 and a projection 65 formed therein, which provides the inclined contact surface 66 . Here, too, the contact surface 66 forms an angle of inclination α with the surrounding surface 38 . By the angle of inclination α is as in the In the previous exemplary embodiments, the adjoining plastic is pressed against the surface 38 during the shrinkage and a form fit is thus achieved.

An alternative embodiment is in 7 shown. This embodiment is also compatible with the 1 shown light module. In contrast to the embodiment of 5 and 6 A barrier 610 is formed with a trapezoidal cross section, the side surface of the recess or groove closer to the section 35 to be sealed or the inner surface of the hollow-cylindrical section 31 of the insert 3 forming the inclined contact surface 66 . The corresponding angle of inclination α is approximately 120° in the exemplary embodiment. During the shrinkage, in this embodiment (but as also in 5 and 6 ) the plastic is pulled towards a center of the inner section 21, so that here too the plastic has shrunk onto the contact surface 66 and is consequently pressed against the surface 38, so that a positive fit is achieved. A leakage path can also be interrupted or completely avoided in this way.

It should be noted that in the case of the lighting module 1, the barriers 61, 62, 610 can also be set up significantly further away from the edge of the edge section 34 than shown here. It is also possible, as in 4 shown to set up several consecutive (e.g. also circumferential) barriers in the insert part 3 of the lighting mode 1 .

Reference List

1

light module

10

substrate, circuit board

11

Light sources, LED chips

18

electronic components, power supply

2

Plastic injection molded part (overmolding)

20

face

21

inner section

24

flange section

200

cylinder barrel section

221

locking part

240

bearing surface

250

bushings

3

insert

30

cooling surface

31

hollow cylindrical section

32

donut-shaped section

33

cooling fins

34

edge section

35

section to be sealed

36

cylindrical inner surface, surrounding surface

36a, 36b

scraped wall sections of the inner surface

37

face inside

38

disc-shaped surface

39

holes, penetrations

4

electrical connection

40

Plastic injection molded part (el. connection)

41

electrical contact pin

42

electrical contact pin

43

socket section

44

socket section

5

sealing ring

60, 61, 62, 610

barrier

66

contact surface

67

groove, indentation

Fs

force alignment (shrinkage process)

S

fissure, delamination

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• US 2019063706 A1 [0037]
• DE 102017214659 A1 [0037]
• US 2019110348 A1 [0037]
• DE 102017217883 A1 [0037]
• DE 102017222649 A1 [0037]
• DE 102018202464 A1 [0037]
• US 2019306939 A1 [0037]
• DE 102018201228 A1 [0037]
• DE 102017213269 A1 [0037]
• DE 102015206471 A1 [0037]
• US 20190063706 A1 [0037]
• US 20190049089 A1 [0037]

Claims (14)

Insert (3) for gas-tight and/or liquid-tight encapsulation with a plastic, comprising: a base body (30, 31, 32, 33) with a surface (36) which has at least one surface section (35) to be sealed by the encapsulation, and a barrier (60, 61, 62, 62, 610) formed in the surface (36) in an edge region (34) of the surface section (35) to be sealed, which has a contact surface (66) which is opposite to which the barrier (60, 61 , 62, 610) surrounding surface (36) is aligned and inclined in such a way that if the plastic is overmoulded, this plastic forms a form fit with the surrounding surface (36) by shrinking onto the contact surface (66) in a cooling process that follows the overmoulding . Insert (3) according to claim 1 , wherein the contact surface (66) forms an angle (α) of more than 90° with the surface (36) surrounding the barrier, so that the contact surface (66) faces the base body (30, 31, 32, 33). Insert (3) according to claim 2 , wherein the bearing surface (66) forms an angle (α) of more than 110° with the surface (36) surrounding the barrier. Insert according to claim 3 , wherein the bearing surface (66) forms an angle (α) of more than 120° with the surface (36) surrounding the barrier. Insert according to one of Claims 1 until 4 , wherein the barrier (60, 61, 62, 610) substantially completely surrounds the surface portion (35) to be sealed. Insert according to one of Claims 1 until 5 , wherein the surface section (35) to be sealed is a section of the surface (36) of the base body (30, 31, 32, 33) which forms an inner surface of a cavity formed in the base body (30, 31, 32, 33), the Edge region (34) represents an opening or an area surrounding the opening. Insert according to one of Claims 1 until 6 , wherein the base body (30, 31, 32, 33) and the barrier (60, 61, 62, 610) are formed in one piece. Insert according to one of Claims 1 until 7 , wherein the base body (30, 31, 32, 33) is made of a metal, in particular aluminum or copper, a ceramic or a plastic. Insert according to one of Claims 1 until 8th , wherein the base body (30, 31, 32, 33) forms a heat sink. Insert according to one of Claims 1 until 9 wherein the barrier (61, 610) is formed along a groove (67) formed in the surface, the abutment surface (66) forming a lateral surface of the groove (67). Insert according to one of Claims 1 until 9 wherein the barrier (60, 62) is formed as a projection projecting from the surface (36) surrounding the barrier. Combination of the insert (3) according to one of Claims 1 until 11 and a plastic injection-moulded part (2), the plastic injection-moulded part (2) having a positive fit due to a cooling process following extrusion coating of the insert (3) by shrinking onto the contact surface (66) of the barrier (60, 61, 62, 610) of the insert (3). with the surrounding surface (36). Semiconductor vehicle lamp (1) for headlights or vehicle auxiliary lighting, comprising: the combination according to claim 12 , and a substrate (10) with at least one semiconductor light source (11) arranged thereon and with a number of electronic components (18) forming a power supply for the at least one semiconductor light source (1); wherein the insert (3) forms a heat sink and the substrate (10) is attached to the heat sink. Method of making the combination according to claim 12 , comprising: providing an insert (3) for the gas-tight and/or liquid-tight encapsulation with a plastic, which comprises a base body (30, 31, 32, 33) with a surface (36) which comprises at least one surface section to be sealed by the encapsulation (35); Forming a barrier (60, 61, 62, 610) in the surface in an edge portion (34) of the surface portion (35) to be sealed, the barrier (60, 61, 62, 610) having a contact surface (66) opposite to the the surface (36) surrounding the barrier (60, 61, 62, 610) is aligned inclined at an angle (α), overmoulding the insert (3) in a mold of an injection molding machine with a plastic to form a the insert (3) at least partially surrounding plastic injection molded part (2); Cooling of the plastic injection molded part (2) so that the plastic shrinks onto the system surface (66) forms a form fit with the surrounding surface (35).

Images