WO2023194207A1 - Lamp for an automobile and a method of manufacturing the same - Google Patents

Lamp for an automobile and a method of manufacturing the same Download PDF

Info

Publication number
WO2023194207A1
WO2023194207A1 PCT/EP2023/058357 EP2023058357W WO2023194207A1 WO 2023194207 A1 WO2023194207 A1 WO 2023194207A1 EP 2023058357 W EP2023058357 W EP 2023058357W WO 2023194207 A1 WO2023194207 A1 WO 2023194207A1
Authority
WO
WIPO (PCT)
Prior art keywords
circuit board
printed circuit
protrusions
push
frame
Prior art date
Application number
PCT/EP2023/058357
Other languages
French (fr)
Inventor
Marek BUDIS
Michal HASEK
David MACHYCEK
Original Assignee
Hella Autotechnik Nova S.R.O.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hella Autotechnik Nova S.R.O. filed Critical Hella Autotechnik Nova S.R.O.
Publication of WO2023194207A1 publication Critical patent/WO2023194207A1/en

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
    • F21S41/10—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source
    • F21S41/14—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source characterised by the type of light source
    • F21S41/141—Light emitting diodes [LED]
    • F21S41/143—Light emitting diodes [LED] the main emission direction of the LED being parallel to the optical axis of the illuminating device
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B11/00—Connecting constructional elements or machine parts by sticking or pressing them together, e.g. cold pressure welding
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
    • F21S41/10—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source
    • F21S41/14—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source characterised by the type of light source
    • F21S41/141—Light emitting diodes [LED]
    • F21S41/151—Light emitting diodes [LED] arranged in one or more lines
    • F21S41/153—Light emitting diodes [LED] arranged in one or more lines arranged in a matrix
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
    • F21S41/10—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source
    • F21S41/19—Attachment of light sources or lamp holders
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
    • F21S41/10—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source
    • F21S41/19—Attachment of light sources or lamp holders
    • F21S41/192—Details of lamp holders, terminals or connectors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
    • F21S41/20—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by refractors, transparent cover plates, light guides or filters
    • F21S41/29—Attachment thereof
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
    • F21S41/50—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by aesthetic components not otherwise provided for, e.g. decorative trim, partition walls or covers
    • F21S41/55—Attachment thereof
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S43/00—Signalling devices specially adapted for vehicle exteriors, e.g. brake lamps, direction indicator lights or reversing lights
    • F21S43/10—Signalling devices specially adapted for vehicle exteriors, e.g. brake lamps, direction indicator lights or reversing lights characterised by the light source
    • F21S43/13—Signalling devices specially adapted for vehicle exteriors, e.g. brake lamps, direction indicator lights or reversing lights characterised by the light source characterised by the type of light source
    • F21S43/15—Strips of light sources
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S43/00—Signalling devices specially adapted for vehicle exteriors, e.g. brake lamps, direction indicator lights or reversing lights
    • F21S43/10—Signalling devices specially adapted for vehicle exteriors, e.g. brake lamps, direction indicator lights or reversing lights characterised by the light source
    • F21S43/19—Attachment of light sources or lamp holders
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S43/00—Signalling devices specially adapted for vehicle exteriors, e.g. brake lamps, direction indicator lights or reversing lights
    • F21S43/10—Signalling devices specially adapted for vehicle exteriors, e.g. brake lamps, direction indicator lights or reversing lights characterised by the light source
    • F21S43/19—Attachment of light sources or lamp holders
    • F21S43/195—Details of lamp holders, terminals or connectors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S43/00—Signalling devices specially adapted for vehicle exteriors, e.g. brake lamps, direction indicator lights or reversing lights
    • F21S43/20—Signalling devices specially adapted for vehicle exteriors, e.g. brake lamps, direction indicator lights or reversing lights characterised by refractors, transparent cover plates, light guides or filters
    • F21S43/27—Attachment thereof
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S43/00—Signalling devices specially adapted for vehicle exteriors, e.g. brake lamps, direction indicator lights or reversing lights
    • F21S43/50—Signalling devices specially adapted for vehicle exteriors, e.g. brake lamps, direction indicator lights or reversing lights characterised by aesthetic components not otherwise provided for, e.g. decorative trim, partition walls or covers
    • F21S43/51—Attachment thereof
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S45/00—Arrangements within vehicle lighting devices specially adapted for vehicle exteriors, for purposes other than emission or distribution of light
    • F21S45/40—Cooling of lighting devices
    • F21S45/47—Passive cooling, e.g. using fins, thermal conductive elements or openings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S45/00—Arrangements within vehicle lighting devices specially adapted for vehicle exteriors, for purposes other than emission or distribution of light
    • F21S45/40—Cooling of lighting devices
    • F21S45/49—Attachment of the cooling means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V21/00—Supporting, suspending, or attaching arrangements for lighting devices; Hand grips

Definitions

  • the present invention relates to a method of manufacturing a lamp for an automobile in which the adhesive between the printed circuit board and the heat sink does not need to be cured in an oven because the board is supported and aligned by push protrusions on the frame of the lamp at least during the hardening of the adhesive.
  • the printed circuit board with LED light sources is standardly glued to the heat sink, which is then screwed to a frame with optical elements. Cylindrical protrusions on the frame may pass through the printed circuit board and/or the frame that to a certain extent align their relative position with respect to the frame.
  • the adhesive layer underneath the printed circuit board and/or the printed circuit board tends to warp, bulge, etc., during the hardening of the adhesive, which may result in rotation or displacement of individual light sources. The light then does not strike the input surfaces of the optical elements at the ideal angle or in the ideal location, such that the luminous intensity of the lamp is reduced.
  • Attaching the frame to the heat sink during the hardening of the adhesive can be made, for example, by screwing. However, it is also possible to utilize gluing, welding, riveting, or connecting by pressing or a latch joint.
  • the frame is attached to the heat sink immediately after the printed circuit board is glued, for example within half an hour of gluing, more preferably within ten minutes of gluing, within five minutes of gluing, etc.
  • the lamp may optionally comprise the preferred step of handling the frame of the lamp during the hardening, i.e., prior to full curing, of the adhesive, after the frame is attached to the heat sink.
  • This handling may comprise, for example, attaching other parts, e.g., optical elements, cover glasses, other light sources, other lamp modules, lamp cover, electronic components, etc. to the frame. It may also comprise packing, storing, or transporting the lamp.
  • the lamp is not heated to cure the adhesive
  • the curing temperature corresponds to the ambient temperature of the manufacturing floor. Due to pressing by the push protrusions, warping of the board or bulging of the adhesive is prevented, such that the adhesive can be allowed to cure at room temperature without adversely affecting the luminous intensity of the lamp.
  • the thickness of the adhesive layer is preferably in the range of 0.05 to 0.2mm, preferably 0.08-0.15mm, for example 0.1 mm.
  • the force from each push protrusion with which the given protrusion pushes against the printed circuit board after attachment of the frame and heat sink is preferably selected in such a way that the total force from all protrusions is from the interval of 75-200N, preferably 100-200N, particularly preferably 130-170N, for example 150N.
  • the shape and position of the push protrusions are adapted to press the printed circuit board evenly against the heat sink. In particular, they are therefore adapted to keep the light sources in plane. More preferably, they are adapted to keep an even thickness of the adhesive layer under the entire printed circuit board.
  • the length of the push protrusions is preferably adapted to exert a defined contact force, or defined pressure, on the printed circuit board after the heat sink is attached to the frame.
  • the method of manufacture may also comprise a step of forming the frame or designing the frame.
  • the size and shape of the printed circuit board and the distribution of the light sources on the board are taken into account with regard to the number, shape, and position of the push protrusions.
  • Other components on the printed circuit board can also affect the number and position of the push protrusions, by default, a higher number of components on the board means a higher stiffness of the board, which may require more push protrusions to sufficiently align it, but sometimes fewer protrusions may be sufficient for a stiffer board because such board holds its planar shape better.
  • the push protrusions are then arranged in such a way that the printed circuit board is aligned in the best possible way.
  • the height of the push protrusions can then affect the amount of the contact force that the frame exerts on the printed circuit board through the push protrusions. This force can then affect the planarity of the board or adhesive layer and the thickness of the adhesive layer.
  • the protrusions of this subset surround the light sources and thus ensure the planarity of the printed circuit board in the area of the light source location. It may also apply to other electronic components, e.g. power connectors, that they are similarly surrounded by at least two push protrusions.
  • At least one push protrusion, or contact point it is also possible to surround at least one push protrusion, or contact point, with light sources. When viewed perpendicularly to the printed circuit board, there may then be another source for each light source, wherein their connecting line intersects a push protrusion or passes between a pair of push protrusions.
  • Another step of the method may be the step of designing and manufacturing the printed circuit board.
  • the contact points between the printed circuit board and the push protrusions are also taken into account.
  • the position of these contact points corresponds to the position of the push protrusions. Since the board cannot carry components at the contact points and preferably does not carry joints either, the number of push protrusions cannot be so high that there is not enough space on the board for all the components or joints that are supposed to be on it.
  • the design of the board may precede the design of the frame, such that the position of the push protrusions is then based on the design of the board and its contact points, wherein the contact points are selected with regard to ensuring sufficient planarity of the board at least in the part where the light sources are placed on it.
  • the printed circuit board is clamped between the at least one push protrusion and the heat sink with a greater force than between the at least one other push protrusion and the heat sink.
  • a greater force can be ensured in particular by varying the length of the push protrusions, or also by hollowing out or elevating some contact points, or by varying the stiffness of some push protrusions or their ends.
  • the contact points arranged around the set of light sources are pushed by a greater force than, for example, the contact points arranged around other components or around the perimeter of the board when they are not also near the light sources. At the location of the light sources, it is most important that the printed circuit board is sufficiently flat.
  • a lamp for an automobile which can be manufactured by the method of the invention and which comprises a frame, a printed circuit board with a non-empty set of light sources, and a heat sink.
  • the printed circuit board is glued to the heat sink and is located between the frame and the heat sink, which are firmly connected together.
  • the frame is provided with a non-empty set of push protrusions for aligning the printed circuit board, and the printed circuit board is clamped between the heat sink with an adhesive layer and the set of push protrusions.
  • the frame therefore acts on the printed circuit board, and through it also on the adhesive, via the push protrusions.
  • the position of the push protrusions is selected in such a way that the printed circuit board is kept flat due to their force action, i.e., e.g., at a constant distance from the heat sink.
  • the printed circuit board comprises a corresponding number of contact points where components are not placed on it and where the push protrusions rest against it.
  • the set of push protrusions may be a fixed part of the frame.
  • the push protrusions can be manufactured during casting, injection moulding, or pressing of the frame.
  • the frame may also comprise alignment protrusions that pass through openings in the printed circuit board or heat sink and define their relative positions.
  • the lamp may comprise a silicon optical element, wherein the set of push protrusions or a subset thereof may then be part of the silicon optical element.
  • the silicone optical element may comprise a collimation protrusion for each light source, wherein the frame then preferably comprises a small frame for the collimation protrusions, which includes openings to stabilize these protrusions. Parts of the silicone optical element may then be clamped between the frame and the printed circuit board such that the frame pushes on the printed circuit board through the silicone material. The position of these silicone push protrusions is then again selected to prevent the board or the adhesive from corrugating.
  • the set of push protrusions comprises at least three push protrusions, wherein contact points with at least three push protrusions on the printed circuit board are positioned around the set of light sources. Ensuring board planarity in the light source location area is preferable because the light sources are most sensitive to printed circuit board deformation - even a small displacement or rotation of the light source can cause the light from it to be misdirected and, for example, more light is reflected from the light guide and less light enters the light guide and is utilized.
  • the set of push protrusions may comprise at least three push protrusions, wherein the contact points with the at least three push protrusions on the printed circuit board are positioned around the perimeter of the printed circuit board. This limits the bending of the edges of the board. These at least three push protrusions may be different from the protrusions surrounding the light sources but may also be the same or some of the protrusions surrounding the light sources may also be located along the edges of the board.
  • the contact points may be, for example, in the centres of the sides of the board.
  • the set of push protrusions comprises preferably at least two push protrusions, wherein each push protrusion comprises a push surface that is in contact with the printed circuit board at the contact point, wherein all the push surfaces lie in a single plane.
  • At least one, preferably each, push protrusion may be provided at its free end with an elastic material having a Young’s modulus of less than 0.5GPa, preferably than 0.2GPa, more preferably less than 0.1 GPa.
  • an elastic material having a Young’s modulus of less than 0.5GPa, preferably than 0.2GPa, more preferably less than 0.1 GPa. Examples of such materials are silicone or rubber.
  • the elastic material at the ends of the push protrusions provides, similar to the utilization of a silicone optical element for the push protrusions, alignment of minor inaccuracies or impurities on the circuit board or push protrusions, variations in the length of the push protrusions, etc.
  • the elastic material may reduce the requirements for precise selection of the contact force from the push protrusions against the board to ensure alignment of the board and the adhesive.
  • Some push protrusions may be 0.05-0.2mm longer than some other push protrusions.
  • the set of push protrusions can be divided into two non-empty subsets, wherein one subset includes protrusions longer than the other.
  • fig. 1 a rear view of the frame of the lamp of the invention is schematically shown, wherein the location of the nine push protrusions is indicated and wherein an array of collimation protrusions of the optical element protrudes from the frame
  • fig. 2 a front view of a printed circuit board is schematically shown at which the contact points with the push protrusions are indicated, wherein the board is glued to the heat sink and includes the light source array and a power connector
  • fig. 3 an exploded perspective rear view of the frame is schematically shown with push protrusions and the heat sink, fig.
  • FIG. 4 an exploded perspective front view of the frame, printed circuit board, and heat sink is schematically shown
  • fig. 5 is a sectional view of the lamp of the invention, wherein the plane of the section is guided by the axis of the lamp and four push protrusions in contact with the printed circuit board are apparent
  • fig. 6 several possible arrangements of the printed circuit board with contact points with the push protrusions are schematically shown.
  • the object of the invention is a method of manufacturing a lamp for an automobile. This method comprises the steps of:
  • the heat sink 4 is preferably a standard aluminium heat sink 4 known from the state of the art.
  • the printed circuit board 3 carries the LED light sources 8 and other possible electronic components.
  • the attachment can be for example screwing or riveting, it is also possible to utilize gluing, welding, or snapping using plastic or metal flexible clips.
  • this step does not heat up the lamp in the oven or similarly accelerate the curing process. Hardening therefore takes place, e.g., at room temperature, e.g., between twenty and thirty degrees Celsius. Depending on the environment, this temperature can generally be, e.g., less than 40°C. Depending on the adhesive used, this step may take several hours to several tens of hours.
  • the printed circuit board 3 is continued to be clamped between the heat sink 4 and the push protrusions 2 during the hardening of the adhesive and is kept aligned by this clamping such that bulging of the adhesive or twisting of the printed circuit board 3 is prevented.
  • the push protrusions 2 are preferably a fixed part of the lamp, the printed circuit board 3 will normally be in contact with the push protrusions 2 even after the adhesive has cured. In some embodiments, however, the push protrusions 2 may be removed after curing because the printed circuit board 3 is no longer subject to deformation.
  • Shin Etsu® KE series adhesive can be used, e.g., KE-1185.
  • the method may further comprise the step of forming the frame 1 with the push protrusions 2.
  • the frame 1 may be formed as is conventional in the state of the art, and in addition the frame 1 is provided with a suitable number of suitably positioned push protrusions 2 which are of one piece with the rest of the frame 1.
  • the number of push protrusions 2 depends in particular on the size of the circuit board 3 and also on its shape and on the number and position of the light sources 8 and other electronic components.
  • the push protrusions 2 are positioned in such a way that each corner of the printed circuit board 3 has a contact point 7 for a push protrusion.
  • At least three push protrusions 2 are positioned around the array of light sources 8.
  • Around the light sources 8 here means, for example, that for each of the at least three push protrusions 2 there is at least one such push protrusion 2 between these protrusions that their connecting line intersects some light source 8 or passes between two adjacent light sources 8, wherein all protrusions do not lie on one straight line.
  • the push protrusions 2 around the light sources 8 are at the same time arranged in a polygon with regular spacing, for example forming the corners of a rhombus or a rectangle.
  • some of the push protrusions 2 of the set of push protrusions 2 are arranged around at least one of the other electronic components on the printed circuit board 3, for example, around the power connector 9.
  • two push protrusions 2 may be located in such a way that their connecting line intersects the given component.
  • some push protrusions 2 may be simultaneously in a corner of the printed circuit board 3 and around the light sources 8 or connector 9.
  • nine push protrusions 2 are utilized and thus also nine contact points 7, wherein six protrusions are at the corners of the board, four form a rhombus around the light sources 8, and two are on the sides of the connector 9.
  • a suitable number of push protrusions 2 may be, e.g., four, spaced regularly around its perimeter.
  • one contact point 7 may be in the middle of this circle.
  • the lamp may comprise, for example, only this one push protrusion 2 in the middle of the light sources 8, or only two between which the array of light sources 8 is located, only said four on the perimeter, etc.
  • the lamp may comprise, for example, up to several tens of push protrusions 2.
  • the design of the printed circuit board 3, where the contact points 7 and their position are taken into account to sufficiently align the printed circuit board 3 or to sufficiently prevent its deformation, preferably at least at the point of location of the light sources 8, may then be another part of the method of the invention.
  • the step of manufacturing the frame 1 may further comprise providing the frame 1 with alignment protrusions 10, which are intended to pass through an opening in the printed circuit board 3 and/or the heat sink 4 to define at least an approximate relative position of these pieces.
  • the method of the invention may then further comprise the step of fixing the openings on the alignment protrusions 10.
  • the alignment protrusions 10 may be, for example, round or conical, or may also have a more complex shape for more precise location alignment. For example, in fig. 3, one alignment protrusion 10 with a cross-section of the shape "+" is apparent.
  • the heat sink 4 may then comprise a complementarily shaped opening, preferably tapered, which clamps the protrusion and ensures that it is centred relative to the centre of the opening during insertion.
  • the step of forming the frame 1 further comprises providing the push protrusions 2, at their free ends, with an elastic material, e.g., rubber or silicone or other material having a Young’s modulus of elasticity below 0.5 GPa.
  • the elastic material will allow the alignment of any impurities on the printed circuit board 3, which will thus not affect the planarity of the board after clamping between the protrusions and the heat sink 4. In addition, it allows the board to be clamped firmly, without the risk of vibration, and at the same time without the risk of damaging the printed circuit board 3.
  • forming the frame 1 may also comprise providing a silicone optical element 11 , wherein the push protrusions 2 are formed completely or in part by the protrusions of the silicone optical element 1J.
  • the given protrusions of the optical element 11 are clamped between the part of the frame 1 and the printed circuit board 3.
  • Such push protrusions 2 provide the same advantages as described above for the provision of the ends with elastic material.
  • the object of the invention is a lamp for an automobile, which can be manufactured by the method described above.
  • This lamp is depicted in an exemplary embodiment in fig. 1 to 5.
  • the lamp comprises a frame 1 which is the main supporting element of the lamp, may be used for fastening it in place in the automobile, may carry other parts such as lenses, cover glasses, and electronic components, and in the present invention further serves to ensure the flat shape of the printed circuit board 3 during the hardening of the adhesive.
  • the lamp comprises the printed circuit board 3 carrying the light sources 8 and glued to the heat sink 4.
  • the frame 1 comprises a non-empty set of push protrusions 2 designed for aligning the printed circuit board 3, wherein the printed circuit board 3 is clamped between the push protrusions 2 and the heat sink 4 with an adhesive layer.
  • the printed circuit board 3 comprises contact points 7 where the push protrusions 2 rest against it and where no components and preferably no joints are located.
  • the push protrusions 2 may be a fixed part of the frame 1, that is, they may for example be made of one plastic casting or moulding.
  • they may be made of a different piece of material than the frame 1, for example, they may be part of the silicone optical element 1 1 embedded in the frame 1, wherein preferably the push protrusions 2 are in such case clamped between the frame 1 and the printed circuit board 3, such that the frame 1 pushes against the board indirectly, through the silicone material.
  • other elastic material can be utilized.
  • the push protrusion 2 may be only one, especially for a smaller printed circuit board 3 and a smaller number of light sources 8, or in the case when the light sources 8 are arranged in a circle, possibly a square, rhombus, etc., and the protrusion may rest against the board in the middle of this circle.
  • a square printed circuit board 3 with an array of light sources 8 approximately in the middle there may be two protrusions in two adjacent corners, and one is in the middle of the opposite rim of the given square shape.
  • At least three push protrusions 2 are then preferably positioned around the light sources 8, that is, for example, they define the corners of the n-gon in which the light sources 8 lie, or at least most of them.
  • at least one push protrusion 2 is rested against each corner of the printed circuit board 3, in the case of a board with shorter rims, there may be one push protrusion 2 in the middle of each rim instead of in the corners.
  • Some other electronic components may preferably also be positioned between at least two push protrusions 2.
  • Each push protrusion 2 preferably has a push surface at its free end, wherein all push surfaces lie in one plane and are in contact with the printed circuit board 3 at the contact point 7. Due to this, all protrusions can ensure the planarity of the printed circuit board 3.
  • the free ends of the push protrusions 2 may be provided with a layer or block of elastic material, e.g., silicone or rubber.
  • the height of the push protrusions 2 affects the amount of contact force applied to the printed circuit board 3, after the frame 1 is connected to the heat sink 4.
  • the contact force is then selected with respect to the number of protrusions, the adhesive used, the material and thickness of the printed circuit board 3, the material of the push protrusions 2, etc., to ensure that the flat shape of the printed circuit board 3 is kept during hardening.
  • the frame 1 may further comprise alignment protrusions 10, which are used to define the relative positions of the components of the lamp.
  • alignment protrusions 10 may be two cylindrical or conical protrusions, wherein the printed circuit board 3 and/or the heat sink 4 comprise openings, e.g., one round and one oval, for the passage of the alignment protrusions 10.
  • the frame 1 carries the silicon optical element 1_1_, it preferably further comprises a small frame 5 for the collimation protrusions.
  • the collimation protrusions 6 are used to link the light from the light sources 8 into the body of the optical element 1J..
  • the small frame 5 for the collimation protrusions which comprises a series of openings through which the collimation protrusions 6 pass to each source and by which the collimation protrusions 6 are held in a precise position.
  • the small frame 5 for the collimation protrusions may be a separate, e.g., metal, piece, or may be a fixed part of the frame 1.
  • the small frame 5 for the collimation protrusions is indicated in figs. 1 and 3 and also in a section in fig. 5.
  • Fig. 1 indicates the location of the nine push protrusions 2 for the irregular hexagon-shaped board carrying the connector 9 and the rectangular array of light sources 8.
  • the printed circuit board 3 with the heat sink 4 is then indicated and the corresponding position of the contact points 7 is indicated.
  • the position of the light sources 8 corresponding to the collimation protrusions 6 of fig. 1 is also apparent, and two openings for the passage of the alignment protrusions 10, located at the edges of the board above the array of light sources 8, are apparent.
  • the frame 1 with the push protrusions 2 is shown in a perspective view.
  • fig. 4 a view in approximately the opposite direction, such that frame 1 is visible from the front, is shown.
  • the contact of the push protrusions 2 with the printed circuit board 3 is apparent. Further, the shape of the silicon optical element 1 1 and the small frame 5 for the collimation protrusions is indicated in this figure. In fig. 6, several other possible positions of the contact points 7 relative to the edges of the printed circuit board 3 and to the array of light sources 8 are indicated. For the sake of simplicity, the individual sources are not shown in this figure but only the area in which the light sources 8 are positioned is indicated.
  • the first drawing in the first row depicts a square printed circuit board 3 with a rectangular array of light sources 8 and with contact points 7 in the corners
  • the first drawing in the second row depicts a square board with an array of light sources 8 in the shape of an annulus, wherein the contact points 7 are in the corners of the board and in the middle of the annulus.
  • the bottom drawing depicts a printed circuit board 3 in the shape of a polygon with two arrays of light sources 8, wherein the contact points 7 are around the perimeter of the board with approximately constant spacing, and the other contact points 7 are arranged in triangles around each of the arrays of light sources 8.
  • the length of some push protrusions 6 may be different, for example by 0.1 mm, from the length of the other push protrusions 6.
  • the protrusions around the set of light sources 8 may be longer and the other protrusions more distant from the sources may be shorter.
  • the protrusion in the middle of the light sources 8 may be longer and the others may be shorter.
  • the two trios of protrusions arranged around the light sources 8 may be longer and the other seven push protrusions 6 located just at the edges of the board may be shorter.
  • the total force from all protrusions may be, for example, 75-200N, preferably 150N.
  • the force for each protrusion may be selected to be in the interval of 8-25N per protrusion, for example, 15-20N.
  • the lamp of the invention and/or manufactured by the method of the invention may be, for example, a headlamp of an automobile. However, it can also be, for example, a rear headlamp or a module for a headlamp, for example, just a module for high beam or low beam, etc.

Abstract

The object of the invention is a method of manufacturing a lamp for an automobile, which comprises the steps of: • Gluing a printed circuit board (3) with light sources (8) to a heat sink (4). • Clamping of the printed circuit board (3) between push protrusions (2) on the frame (1) of the lamp and the heat sink (4). • Hardening of the adhesive at a temperature below 40°C. During the hardening, the printed circuit board (3) and the adhesive layer between the push protrusions (2) on the frame (1) and the heat sink (4) are kept aligned, wherein the hardening takes at least 1 hour. and • Attaching the frame (1) to the heat sink (4) during the hardening of the adhesive. This ensures that the planarity of the printed circuit board (3) is maintained without the need for curing in an oven and the lamp can be handled during the hardening of the adhesive. Further, the object of the invention is a lamp manufactured by this method.

Description

Lamp for an automobile and a method of manufacturing the same
Field of the Invention
The present invention relates to a method of manufacturing a lamp for an automobile in which the adhesive between the printed circuit board and the heat sink does not need to be cured in an oven because the board is supported and aligned by push protrusions on the frame of the lamp at least during the hardening of the adhesive.
Background of the Invention
In the current state of the art, in the manufacture of lamps, especially for automobiles, the printed circuit board with LED light sources is standardly glued to the heat sink, which is then screwed to a frame with optical elements. Cylindrical protrusions on the frame may pass through the printed circuit board and/or the frame that to a certain extent align their relative position with respect to the frame. However, the adhesive layer underneath the printed circuit board and/or the printed circuit board tends to warp, bulge, etc., during the hardening of the adhesive, which may result in rotation or displacement of individual light sources. The light then does not strike the input surfaces of the optical elements at the ideal angle or in the ideal location, such that the luminous intensity of the lamp is reduced.
In the state of the art, this bulging of the adhesive or deforming of the printed circuit board during the hardening of the adhesive at room temperature, which normally takes approx, one day, is prevented by curing the adhesive in an oven. At elevated temperature, the adhesive can cure in several minutes or tens of minutes, and no warping of the printed circuit board occurs. However, a suitable oven is required for the manufacture of lamps and the curing step at elevated temperature is very energy intensive, which makes the manufacture more expensive and less environmentally friendly.
It would therefore be advisable to come up with a solution that would ensure curing of the adhesive without warping the printed circuit board or bulging the adhesive, without the need to cure the adhesive in the oven.
Summary of the Invention
The shortcomings of the solutions known from the state of the art are to a certain extent eliminated by a method of manufacturing an automobile lamp, which comprises the steps of:
• Gluing a printed circuit board, which carries a non-empty set of light sources, to a heat sink;
• Clamping of the printed circuit board between a non-empty set of push protrusions on the frame and the heat sink. Preferably, as a result of this step, the printed circuit board is pressed evenly against the heat sink, and the adhesive layer has an even thickness.
• Attaching the frame to the heat sink during the hardening of the adhesive. The attachment can be made, for example, by screwing. However, it is also possible to utilize gluing, welding, riveting, or connecting by pressing or a latch joint. Preferably, the frame is attached to the heat sink immediately after the printed circuit board is glued, for example within half an hour of gluing, more preferably within ten minutes of gluing, within five minutes of gluing, etc.
• Leaving the adhesive to cure at a temperature below 40°C, for example below 30°C, wherein during the hardening the printed circuit board and the adhesive layer between the push protrusions and the heat sink are kept aligned. The push protrusions therefore exert a force on the board at least until curing. Due to the absence of acceleration of curing, in particular oven curing as is usual in the state of the art, curing takes at least one hour.
Further, the lamp may optionally comprise the preferred step of handling the frame of the lamp during the hardening, i.e., prior to full curing, of the adhesive, after the frame is attached to the heat sink. This handling may comprise, for example, attaching other parts, e.g., optical elements, cover glasses, other light sources, other lamp modules, lamp cover, electronic components, etc. to the frame. It may also comprise packing, storing, or transporting the lamp. By attaching the heat sink to the frame, which also secures the position and shape of the printed circuit board thanks to the push protrusions, even though the glued joint is not yet fully cured at least for part of this handling, any further movement of the printed circuit board relative to the frame or heat sink is prevented and its warping is prevented.
Thus, in the method of the invention, the lamp is not heated to cure the adhesive, the curing temperature corresponds to the ambient temperature of the manufacturing floor. Due to pressing by the push protrusions, warping of the board or bulging of the adhesive is prevented, such that the adhesive can be allowed to cure at room temperature without adversely affecting the luminous intensity of the lamp. This eliminates the need for a curing oven for the manufacture of lamps, reduces the energy intensity of manufacture, and thus the cost and environmental burden of the manufacture. For example, it is not necessary to wait for the adhesive to cure or to accelerate the curing in any way in order to continue the installation of the lamp and the finished lamps can be, for example, immediately palletised and/or transported, etc. Curing of the adhesive may take 1 -24 hours, for example 2 to 24 hours. The thickness of the adhesive layer is preferably in the range of 0.05 to 0.2mm, preferably 0.08-0.15mm, for example 0.1 mm. The force from each push protrusion with which the given protrusion pushes against the printed circuit board after attachment of the frame and heat sink is preferably selected in such a way that the total force from all protrusions is from the interval of 75-200N, preferably 100-200N, particularly preferably 130-170N, for example 150N.
The shape and position of the push protrusions are adapted to press the printed circuit board evenly against the heat sink. In particular, they are therefore adapted to keep the light sources in plane. More preferably, they are adapted to keep an even thickness of the adhesive layer under the entire printed circuit board. The length of the push protrusions is preferably adapted to exert a defined contact force, or defined pressure, on the printed circuit board after the heat sink is attached to the frame.
The method of manufacture may also comprise a step of forming the frame or designing the frame. When designing the frame, the size and shape of the printed circuit board and the distribution of the light sources on the board are taken into account with regard to the number, shape, and position of the push protrusions. Other components on the printed circuit board can also affect the number and position of the push protrusions, by default, a higher number of components on the board means a higher stiffness of the board, which may require more push protrusions to sufficiently align it, but sometimes fewer protrusions may be sufficient for a stiffer board because such board holds its planar shape better. Based on this, the push protrusions are then arranged in such a way that the printed circuit board is aligned in the best possible way. The height of the push protrusions can then affect the amount of the contact force that the frame exerts on the printed circuit board through the push protrusions. This force can then affect the planarity of the board or adhesive layer and the thickness of the adhesive layer.
Preferably, there are at least three push protrusions, not lying on the same straight line. Preferably, there is at least a three-element subset of the set of push protrusions, wherein for each protrusion from that subset, there is another protrusion from this subset, wherein some connecting line of these two protrusions intersects a light source when viewed perpendicularly to the printed circuit board or passes between two light sources. Thus, the protrusions of this subset surround the light sources and thus ensure the planarity of the printed circuit board in the area of the light source location. It may also apply to other electronic components, e.g. power connectors, that they are similarly surrounded by at least two push protrusions.
Alternatively or additionally, it is also possible to surround at least one push protrusion, or contact point, with light sources. When viewed perpendicularly to the printed circuit board, there may then be another source for each light source, wherein their connecting line intersects a push protrusion or passes between a pair of push protrusions.
Another step of the method may be the step of designing and manufacturing the printed circuit board. In addition to the number and position of the light sources and the other electronic components, as is customary, the contact points between the printed circuit board and the push protrusions are also taken into account. The position of these contact points corresponds to the position of the push protrusions. Since the board cannot carry components at the contact points and preferably does not carry joints either, the number of push protrusions cannot be so high that there is not enough space on the board for all the components or joints that are supposed to be on it. The design of the board may precede the design of the frame, such that the position of the push protrusions is then based on the design of the board and its contact points, wherein the contact points are selected with regard to ensuring sufficient planarity of the board at least in the part where the light sources are placed on it.
Preferably, in the step of clamping of the printed circuit board, the printed circuit board is clamped between the at least one push protrusion and the heat sink with a greater force than between the at least one other push protrusion and the heat sink. This can be ensured in particular by varying the length of the push protrusions, or also by hollowing out or elevating some contact points, or by varying the stiffness of some push protrusions or their ends. Preferably, the contact points arranged around the set of light sources are pushed by a greater force than, for example, the contact points arranged around other components or around the perimeter of the board when they are not also near the light sources. At the location of the light sources, it is most important that the printed circuit board is sufficiently flat. On the rest of the printed circuit board, minor bulges may not affect the function of the lamp. The push protrusions pushing with less force do not put too much strain on the printed circuit board but reduce the pressure from the protrusions with more force, such that there is no risk of, e.g., damage to the board by too much pressure, and ensure sufficient planarity of the board in the given location. For example, sufficient planarity of the board near the sources can be achieved with less overall force exerted on the screw or other connection between the frame and the heat sink.
The shortcomings of the solutions known in the state of art are further eliminated to a certain extent by a lamp for an automobile which can be manufactured by the method of the invention and which comprises a frame, a printed circuit board with a non-empty set of light sources, and a heat sink. The printed circuit board is glued to the heat sink and is located between the frame and the heat sink, which are firmly connected together. The frame is provided with a non-empty set of push protrusions for aligning the printed circuit board, and the printed circuit board is clamped between the heat sink with an adhesive layer and the set of push protrusions.
The frame therefore acts on the printed circuit board, and through it also on the adhesive, via the push protrusions. The position of the push protrusions is selected in such a way that the printed circuit board is kept flat due to their force action, i.e., e.g., at a constant distance from the heat sink. Preferably, there are at least three push protrusions and they surround the light source array. The printed circuit board comprises a corresponding number of contact points where components are not placed on it and where the push protrusions rest against it.
The set of push protrusions may be a fixed part of the frame. In particular, the push protrusions can be manufactured during casting, injection moulding, or pressing of the frame. In addition to the push protrusions, the frame may also comprise alignment protrusions that pass through openings in the printed circuit board or heat sink and define their relative positions.
The lamp may comprise a silicon optical element, wherein the set of push protrusions or a subset thereof may then be part of the silicon optical element. The silicone optical element may comprise a collimation protrusion for each light source, wherein the frame then preferably comprises a small frame for the collimation protrusions, which includes openings to stabilize these protrusions. Parts of the silicone optical element may then be clamped between the frame and the printed circuit board such that the frame pushes on the printed circuit board through the silicone material. The position of these silicone push protrusions is then again selected to prevent the board or the adhesive from corrugating.
Preferably, the set of push protrusions comprises at least three push protrusions, wherein contact points with at least three push protrusions on the printed circuit board are positioned around the set of light sources. Ensuring board planarity in the light source location area is preferable because the light sources are most sensitive to printed circuit board deformation - even a small displacement or rotation of the light source can cause the light from it to be misdirected and, for example, more light is reflected from the light guide and less light enters the light guide and is utilized. The set of push protrusions may comprise at least three push protrusions, wherein the contact points with the at least three push protrusions on the printed circuit board are positioned around the perimeter of the printed circuit board. This limits the bending of the edges of the board. These at least three push protrusions may be different from the protrusions surrounding the light sources but may also be the same or some of the protrusions surrounding the light sources may also be located along the edges of the board.
For example, there may be a contact point with some push protrusion in each corner of the printed circuit board. Alternatively or additionally, the contact points may be, for example, in the centres of the sides of the board.
The set of push protrusions comprises preferably at least two push protrusions, wherein each push protrusion comprises a push surface that is in contact with the printed circuit board at the contact point, wherein all the push surfaces lie in a single plane.
At least one, preferably each, push protrusion may be provided at its free end with an elastic material having a Young’s modulus of less than 0.5GPa, preferably than 0.2GPa, more preferably less than 0.1 GPa. Examples of such materials are silicone or rubber. The elastic material at the ends of the push protrusions provides, similar to the utilization of a silicone optical element for the push protrusions, alignment of minor inaccuracies or impurities on the circuit board or push protrusions, variations in the length of the push protrusions, etc. In addition, the elastic material may reduce the requirements for precise selection of the contact force from the push protrusions against the board to ensure alignment of the board and the adhesive.
Some push protrusions may be 0.05-0.2mm longer than some other push protrusions. For example, the set of push protrusions can be divided into two non-empty subsets, wherein one subset includes protrusions longer than the other. For example, there may exist such a distance threshold that the protrusions that are closer to a light source than this threshold are longer than protrusions that are equidistant or further away from all sources than this threshold. Description of the Drawings
A summary of the invention is further clarified using examples of embodiments thereof, which are described with reference to the accompanying drawings, where in: fig. 1 a rear view of the frame of the lamp of the invention is schematically shown, wherein the location of the nine push protrusions is indicated and wherein an array of collimation protrusions of the optical element protrudes from the frame, fig. 2 a front view of a printed circuit board is schematically shown at which the contact points with the push protrusions are indicated, wherein the board is glued to the heat sink and includes the light source array and a power connector, fig. 3 an exploded perspective rear view of the frame is schematically shown with push protrusions and the heat sink, fig. 4 an exploded perspective front view of the frame, printed circuit board, and heat sink is schematically shown, fig. 5 is a sectional view of the lamp of the invention, wherein the plane of the section is guided by the axis of the lamp and four push protrusions in contact with the printed circuit board are apparent, and in fig. 6 several possible arrangements of the printed circuit board with contact points with the push protrusions are schematically shown.
Exemplary Embodiments of the Invention
The invention will be further clarified using examples of the embodiments with reference to the respective drawings. The object of the invention is a method of manufacturing a lamp for an automobile. This method comprises the steps of:
• gluing the printed circuit board 3 to the heat sink 4. The heat sink 4 is preferably a standard aluminium heat sink 4 known from the state of the art. At the same time, the printed circuit board 3 carries the LED light sources 8 and other possible electronic components.
• Clamping of the printed circuit board 3 between the heat sink 4 and the frame 1_of the lamp, wherein the frame 1 is in contact with the printed circuit board 3 via the push protrusions 2. Each push protrusion 2 is in contact with the printed circuit board 3 at a contact point 7, where there are no components and preferably no printed circuits on the printed circuit board 3.
• Attaching the frame 1 to the heat sink 4. The attachment can be for example screwing or riveting, it is also possible to utilize gluing, welding, or snapping using plastic or metal flexible clips.
• Leaving the adhesive to cure. In particular, this step does not heat up the lamp in the oven or similarly accelerate the curing process. Hardening therefore takes place, e.g., at room temperature, e.g., between twenty and thirty degrees Celsius. Depending on the environment, this temperature can generally be, e.g., less than 40°C. Depending on the adhesive used, this step may take several hours to several tens of hours. At the same time, the printed circuit board 3 is continued to be clamped between the heat sink 4 and the push protrusions 2 during the hardening of the adhesive and is kept aligned by this clamping such that bulging of the adhesive or twisting of the printed circuit board 3 is prevented.
• Further handling of the frame 1 with the heat sink 4 and printed circuit board 3 attached, wherein at least part of this handling takes place before the adhesive has fully cured. For example, it may be the installation of other parts of the lamp such as a cover or cover glass, packaging of the lamp, installation in the automobile, etc. Due to the clamping of the printed circuit board 3, there is no risk of the lamp being deflected, even though the adhesive is not yet cured.
Since the push protrusions 2 are preferably a fixed part of the lamp, the printed circuit board 3 will normally be in contact with the push protrusions 2 even after the adhesive has cured. In some embodiments, however, the push protrusions 2 may be removed after curing because the printed circuit board 3 is no longer subject to deformation. For example, Shin Etsu® KE series adhesive can be used, e.g., KE-1185.
Prior to the step of clamping of the printed circuit board 3, the method may further comprise the step of forming the frame 1 with the push protrusions 2. In this step, the frame 1 may be formed as is conventional in the state of the art, and in addition the frame 1 is provided with a suitable number of suitably positioned push protrusions 2 which are of one piece with the rest of the frame 1. The number of push protrusions 2 depends in particular on the size of the circuit board 3 and also on its shape and on the number and position of the light sources 8 and other electronic components. For example, the push protrusions 2 are positioned in such a way that each corner of the printed circuit board 3 has a contact point 7 for a push protrusion. Preferably, at least three push protrusions 2 are positioned around the array of light sources 8. Around the light sources 8 here means, for example, that for each of the at least three push protrusions 2 there is at least one such push protrusion 2 between these protrusions that their connecting line intersects some light source 8 or passes between two adjacent light sources 8, wherein all protrusions do not lie on one straight line. Preferably, the push protrusions 2 around the light sources 8 are at the same time arranged in a polygon with regular spacing, for example forming the corners of a rhombus or a rectangle. Preferably, further, some of the push protrusions 2 of the set of push protrusions 2 are arranged around at least one of the other electronic components on the printed circuit board 3, for example, around the power connector 9. For example, two push protrusions 2 may be located in such a way that their connecting line intersects the given component. At the same time, as is apparent, e.g., from fig. 2, some push protrusions 2 may be simultaneously in a corner of the printed circuit board 3 and around the light sources 8 or connector 9. For example, in the embodiment depicted, nine push protrusions 2 are utilized and thus also nine contact points 7, wherein six protrusions are at the corners of the board, four form a rhombus around the light sources 8, and two are on the sides of the connector 9.
In the case of a round or oval printed circuit board 3, a suitable number of push protrusions 2 may be, e.g., four, spaced regularly around its perimeter. In the case of arranging the array of light sources 8 in a circle, one contact point 7 may be in the middle of this circle. If the printed circuit board 3 is sufficiently small, the lamp may comprise, for example, only this one push protrusion 2 in the middle of the light sources 8, or only two between which the array of light sources 8 is located, only said four on the perimeter, etc. In contrast, in the case of a larger printed circuit board 3 with a more complicated shape, more arrays of light sources 8, more additional components, etc., the lamp may comprise, for example, up to several tens of push protrusions 2. When designing the printed circuit board 3, it is then necessary to take into account the empty contact points 7 where no parts are located, or the openings for the alignment protrusions 10 described below.
The design of the printed circuit board 3, where the contact points 7 and their position are taken into account to sufficiently align the printed circuit board 3 or to sufficiently prevent its deformation, preferably at least at the point of location of the light sources 8, may then be another part of the method of the invention.
The step of manufacturing the frame 1 may further comprise providing the frame 1 with alignment protrusions 10, which are intended to pass through an opening in the printed circuit board 3 and/or the heat sink 4 to define at least an approximate relative position of these pieces. The method of the invention may then further comprise the step of fixing the openings on the alignment protrusions 10. The alignment protrusions 10 may be, for example, round or conical, or may also have a more complex shape for more precise location alignment. For example, in fig. 3, one alignment protrusion 10 with a cross-section of the shape "+" is apparent. The heat sink 4 may then comprise a complementarily shaped opening, preferably tapered, which clamps the protrusion and ensures that it is centred relative to the centre of the opening during insertion.
Preferably, the step of forming the frame 1 further comprises providing the push protrusions 2, at their free ends, with an elastic material, e.g., rubber or silicone or other material having a Young’s modulus of elasticity below 0.5 GPa. The elastic material will allow the alignment of any impurities on the printed circuit board 3, which will thus not affect the planarity of the board after clamping between the protrusions and the heat sink 4. In addition, it allows the board to be clamped firmly, without the risk of vibration, and at the same time without the risk of damaging the printed circuit board 3. In some embodiments, forming the frame 1 may also comprise providing a silicone optical element 11 , wherein the push protrusions 2 are formed completely or in part by the protrusions of the silicone optical element 1J.. Preferably, the given protrusions of the optical element 11 are clamped between the part of the frame 1 and the printed circuit board 3. Such push protrusions 2 provide the same advantages as described above for the provision of the ends with elastic material.
Further, the object of the invention is a lamp for an automobile, which can be manufactured by the method described above. This lamp is depicted in an exemplary embodiment in fig. 1 to 5. The lamp comprises a frame 1 which is the main supporting element of the lamp, may be used for fastening it in place in the automobile, may carry other parts such as lenses, cover glasses, and electronic components, and in the present invention further serves to ensure the flat shape of the printed circuit board 3 during the hardening of the adhesive. Further, the lamp comprises the printed circuit board 3 carrying the light sources 8 and glued to the heat sink 4.
The frame 1 comprises a non-empty set of push protrusions 2 designed for aligning the printed circuit board 3, wherein the printed circuit board 3 is clamped between the push protrusions 2 and the heat sink 4 with an adhesive layer. The printed circuit board 3 comprises contact points 7 where the push protrusions 2 rest against it and where no components and preferably no joints are located. The push protrusions 2 may be a fixed part of the frame 1, that is, they may for example be made of one plastic casting or moulding. In some embodiments, they may be made of a different piece of material than the frame 1, for example, they may be part of the silicone optical element 1 1 embedded in the frame 1, wherein preferably the push protrusions 2 are in such case clamped between the frame 1 and the printed circuit board 3, such that the frame 1 pushes against the board indirectly, through the silicone material. Similarly, other elastic material can be utilized.
The push protrusion 2 may be only one, especially for a smaller printed circuit board 3 and a smaller number of light sources 8, or in the case when the light sources 8 are arranged in a circle, possibly a square, rhombus, etc., and the protrusion may rest against the board in the middle of this circle. Preferably, however, there is a plurality of push protrusions 2, e.g., at least three. For example, for a square printed circuit board 3 with an array of light sources 8 approximately in the middle, there may be two protrusions in two adjacent corners, and one is in the middle of the opposite rim of the given square shape. Alternatively, for a square board, there may be four protrusions, in each corner or each centre of the rim. For more complicated shapes of printed circuit boards 3 or for boards with larger surface, there can be even more push protrusions 2, e.g., 5-10. At least three push protrusions 2 are then preferably positioned around the light sources 8, that is, for example, they define the corners of the n-gon in which the light sources 8 lie, or at least most of them. Preferably, at least one push protrusion 2 is rested against each corner of the printed circuit board 3, in the case of a board with shorter rims, there may be one push protrusion 2 in the middle of each rim instead of in the corners. Some other electronic components may preferably also be positioned between at least two push protrusions 2.
Each push protrusion 2 preferably has a push surface at its free end, wherein all push surfaces lie in one plane and are in contact with the printed circuit board 3 at the contact point 7. Due to this, all protrusions can ensure the planarity of the printed circuit board 3. In some embodiments, the free ends of the push protrusions 2 may be provided with a layer or block of elastic material, e.g., silicone or rubber.
The height of the push protrusions 2 affects the amount of contact force applied to the printed circuit board 3, after the frame 1 is connected to the heat sink 4. The contact force is then selected with respect to the number of protrusions, the adhesive used, the material and thickness of the printed circuit board 3, the material of the push protrusions 2, etc., to ensure that the flat shape of the printed circuit board 3 is kept during hardening.
The frame 1 may further comprise alignment protrusions 10, which are used to define the relative positions of the components of the lamp. For example, there may be two cylindrical or conical protrusions, wherein the printed circuit board 3 and/or the heat sink 4 comprise openings, e.g., one round and one oval, for the passage of the alignment protrusions 10. In embodiments where the frame 1 carries the silicon optical element 1_1_, it preferably further comprises a small frame 5 for the collimation protrusions. The collimation protrusions 6 are used to link the light from the light sources 8 into the body of the optical element 1J.. Due to the elasticity of the material, it is then preferable to utilize the small frame 5 for the collimation protrusions, which comprises a series of openings through which the collimation protrusions 6 pass to each source and by which the collimation protrusions 6 are held in a precise position. The small frame 5 for the collimation protrusions may be a separate, e.g., metal, piece, or may be a fixed part of the frame 1. The small frame 5 for the collimation protrusions is indicated in figs. 1 and 3 and also in a section in fig. 5.
Fig. 1 indicates the location of the nine push protrusions 2 for the irregular hexagon-shaped board carrying the connector 9 and the rectangular array of light sources 8. In fig. 2, the printed circuit board 3 with the heat sink 4 is then indicated and the corresponding position of the contact points 7 is indicated. The position of the light sources 8 corresponding to the collimation protrusions 6 of fig. 1 is also apparent, and two openings for the passage of the alignment protrusions 10, located at the edges of the board above the array of light sources 8, are apparent. In fig. 3, the frame 1 with the push protrusions 2 is shown in a perspective view. In fig. 4, a view in approximately the opposite direction, such that frame 1 is visible from the front, is shown. In the section in fig. 5, the contact of the push protrusions 2 with the printed circuit board 3 is apparent. Further, the shape of the silicon optical element 1 1 and the small frame 5 for the collimation protrusions is indicated in this figure. In fig. 6, several other possible positions of the contact points 7 relative to the edges of the printed circuit board 3 and to the array of light sources 8 are indicated. For the sake of simplicity, the individual sources are not shown in this figure but only the area in which the light sources 8 are positioned is indicated. For example, the first drawing in the first row depicts a square printed circuit board 3 with a rectangular array of light sources 8 and with contact points 7 in the corners, the first drawing in the second row depicts a square board with an array of light sources 8 in the shape of an annulus, wherein the contact points 7 are in the corners of the board and in the middle of the annulus. The bottom drawing depicts a printed circuit board 3 in the shape of a polygon with two arrays of light sources 8, wherein the contact points 7 are around the perimeter of the board with approximately constant spacing, and the other contact points 7 are arranged in triangles around each of the arrays of light sources 8.
In some embodiments, the length of some push protrusions 6 may be different, for example by 0.1 mm, from the length of the other push protrusions 6. For example, the protrusions around the set of light sources 8 may be longer and the other protrusions more distant from the sources may be shorter. For example, in the embodiment shown in the first drawing in the second row of fig. 6, the protrusion in the middle of the light sources 8 may be longer and the others may be shorter. For the embodiment of the drawing in the third row of this figure, the two trios of protrusions arranged around the light sources 8 may be longer and the other seven push protrusions 6 located just at the edges of the board may be shorter. This ensures sufficient alignment of the printed circuit board 3 near the sources, while the shorter protrusions reduce pressure from the longer ones and ensure the planarity of the board in the locations where there are less demands on it. The total force from all protrusions may be, for example, 75-200N, preferably 150N. Alternatively, the force for each protrusion may be selected to be in the interval of 8-25N per protrusion, for example, 15-20N.
The lamp of the invention and/or manufactured by the method of the invention may be, for example, a headlamp of an automobile. However, it can also be, for example, a rear headlamp or a module for a headlamp, for example, just a module for high beam or low beam, etc.
List of Reference Numerals
1 - Frame
2 - Push protrusion
3 - Printed circuit board
4 - Heat sink
5 - Small frame for collimation protrusions
6 - Collimation protrusion
7 - Contact point
8 - Light source
9 - Connector
10 - Alignment protrusion
11 - Optical element

Claims

CLAIMS A method of manufacturing a lamp for an automobile, characterised in that it comprises the steps of:
• Gluing a printed circuit board (3) carrying a set of light sources (8) to a heat sink (4);
• Clamping of the printed circuit board (3) between a non-empty set of push protrusions (2) on the frame (1 ) of the lamp and the heat sink (4);
• Hardening of the adhesive at a temperature below 40°C, wherein during the hardening, the printed circuit board (3) and the adhesive layer between the push protrusions (2) on the frame (1 ) and the heat sink (4) are kept aligned and the hardening takes at least 1 hour; and
• Attaching the frame (1 ) to the heat sink (4) during the hardening of the adhesive. The method of manufacturing according to claim 1 , characterised in that the hardening of the adhesive takes place without heating in an oven. The method of manufacturing according to any one of the preceding claims, characterised in that it further comprises the step of handling the frame (1 ) of the lamp during the hardening of the adhesive, after the frame (1 ) has been attached to the heat sink (4). The method of manufacturing according to any one of the preceding claims, characterised in that in the step of clamping of the printed circuit board (3), the printed circuit board (3) is clamped between at least one push protrusion (2) and the heat sink (4) with a greater force than between at least one other push protrusion (2) and the heat sink (4). A lamp for an automobile comprising a frame (1 ), a printed circuit board (3) with a set of light sources (8), and a heat sink (4), wherein the printed circuit board (3) is glued to the heat sink (4) via an adhesive layer, and is located between the frame (1 ) and the heat sink (4), which are firmly connected together, characterised in that the frame (1 ) is provided with a set of push protrusions (2) for aligning the printed circuit board (3), and the printed circuit board (3) is clamped between the heat sink (4) with the adhesive layer and the set of push protrusions (2). The lamp according to claim 5, characterised in that the set of push protrusions
(2) is a fixed part of the frame (1 ). The lamp according to claim 5, characterised in that it further comprises a silicon optical element (1 1 ), wherein the set of push protrusions (2) is part of the silicon optical element (1 1 ). The lamp according to any one of claims 5 to 7, characterised in that the set of push protrusions (2) comprises at least three push protrusions (2), wherein contact points (7) between the at least three push protrusions (2) and the printed circuit board (3) are positioned around the set of light sources (8) on the printed circuit board. The lamp according to any one of claims 5 to 8, characterised in that the set of push protrusions (2) comprises at least three push protrusions (2), wherein the contact points (7) between the at least three push protrusions (2) and the printed circuit board (3) are positioned around the perimeter of the printed circuit board
(3). The lamp according to claim 9, characterised in that in each corner of the printed circuit board (3), there is a contact point (7) with some push protrusion (2). The lamp according to any one of claims 5 to 10, characterised in that at least one push protrusion (2) is provided at its free end with an elastic material having a Young’s modulus of less than 0.5 GPa. The lamp according to any one of claims 5 to 1 1 , characterised in that the set of push protrusions (2) includes at least one protrusion that is 0.05-0.2 mm shorter than at least one other push protrusion (2) of the set of push protrusions (2).
PCT/EP2023/058357 2022-04-05 2023-03-30 Lamp for an automobile and a method of manufacturing the same WO2023194207A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CZPV2022-145 2022-04-05
CZ2022-145A CZ2022145A3 (en) 2022-04-05 2022-04-05 A lamp for a car and a method of its manufacture

Publications (1)

Publication Number Publication Date
WO2023194207A1 true WO2023194207A1 (en) 2023-10-12

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CZ (1) CZ2022145A3 (en)
WO (1) WO2023194207A1 (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180087736A1 (en) * 2016-09-29 2018-03-29 Valeo Vision Optical module for a motor vehicle
US20180283647A1 (en) * 2017-03-30 2018-10-04 Valeo North America, Inc. Position frame for light source
DE102017122560A1 (en) * 2017-09-28 2019-03-28 Automotive Lighting Reutlingen Gmbh LED headlamp module
WO2021103923A1 (en) * 2019-11-30 2021-06-03 华域视觉科技(上海)有限公司 Vehicle lamp module, vehicle lamp and vehicle
DE112018008084T5 (en) * 2018-10-18 2021-07-08 Mitsubishi Electric Corporation Circuit board housing

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180087736A1 (en) * 2016-09-29 2018-03-29 Valeo Vision Optical module for a motor vehicle
US20180283647A1 (en) * 2017-03-30 2018-10-04 Valeo North America, Inc. Position frame for light source
DE102017122560A1 (en) * 2017-09-28 2019-03-28 Automotive Lighting Reutlingen Gmbh LED headlamp module
DE112018008084T5 (en) * 2018-10-18 2021-07-08 Mitsubishi Electric Corporation Circuit board housing
WO2021103923A1 (en) * 2019-11-30 2021-06-03 华域视觉科技(上海)有限公司 Vehicle lamp module, vehicle lamp and vehicle

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