METHOD FOR PRODUCING SUPPORT STRUCTURES FOR LIGHTING DEVICES AND CORRESPONDING DEVICE

Abstract

A method for forming support structures for electrically-powered lighting devices, the method comprising: providing an electrically insulating ribbon-like substrate, forming electrically-conductive lines on a surface of the substrate by screen printing of electrically-conductive ink, the screen printing comprising printing a plurality of repeated printed images, which follow one another along a longitudinal direction and are separated from each other by separation gaps, and forming electrically-conductive ink jumpers that extend through the separation gaps and which provide electrical continuity between electrically-conductive lines of adjacent printed images, wherein forming ink jumpers comprises delivering electrically-conductive ink by inkjet printing.

Claims

1. A method for forming support structures for electrically-powered lighting devices, the method comprising: providing an electrically insulating ribbon-like substrate, forming electrically-conductive lines on a surface of the substrate by screen printing of electrically-conductive ink, the screen printing comprising printing a plurality of repeated printed images, which follow one another along a longitudinal direction and are separated from each other by separation gaps, and forming electrically-conductive ink jumpers that extend through the separation gaps and which provide electrical continuity between electrically-conductive lines of adjacent printed images, wherein forming ink jumpers comprises delivering electrically-conductive ink by inkjet printing.

2. The method according to claim 1, further comprising curing the electrically-conductive ink after the screen printing and forming the ink jumpers.

3. The method according to claim 1, wherein the ink jumpers connect facing ends of respective bus lines of adjacent printed images to each other.

4. The method according to claim 1, wherein delivering electrically-conductive ink by inkjet printing comprises injecting electrically-conductive ink by means of at least one nozzle not in contact with the electrically-conductive ink applied by screen printing.

5. The method according to claim 3, further comprising applying the electrically-powered light radiation sources to the electrically-conductive lines after curing the electrically-conductive ink.

6. The method according to claim 1, further comprising providing the ribbon-like substrate as a reel, and screen printing the electrically-conductive ink on the ribbon-like substrate in a reel-to-reel process.

7. The method according to claim 1, further comprising subdividing the support structure into a plurality of ribbon-like modules co-extending along the length of the support structure.

8. A lighting device, comprising: a support structure produced with the method comprising: providing an electrically insulating ribbon-like substrate, forming electrically-conductive lines on a surface of the substrate by screen printing of electrically-conductive ink, the screen printing comprising printing a plurality of repeated printed images, which follow one another along a longitudinal direction and are separated from each other by separation gaps, and forming electrically-conductive ink jumpers that extend through the separation gaps and which provide electrical continuity between electrically-conductive lines of adjacent printed images, wherein forming ink jumpers comprises delivering electrically-conductive ink by inkjet printing; and electrically-powered light radiation sources arranged on the support structure with the light radiation sources electrically coupled to the electrically-conductive lines.

9. The lighting device according to claim 8, wherein: the electrically-powered light radiation sources comprise LED sources, and/or the electrically-powered light radiation sources are mounted onto the support structure with SMT technology.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In the drawings, like reference characters generally refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various aspects are described with reference to the following drawings, in which:

[0033] FIG. 1 exemplifies a screen printing step,

[0034] FIG. 2 is a schematic cross-section along the line II-II of FIG. 1,

[0035] FIG. 3 exemplifies the formation of ink jumpers,

[0036] FIG. 4 is an schematic cross-section along the line IV-IV of FIG. 3, and

[0037] FIG. 5 exemplifies the application of light radiation sources.

DETAILED DESCRIPTION

[0038] In the following description various specific details are illustrated aimed at a thorough understanding of examples of embodiments of the present description. One or more embodiments may be implemented without one or more of the specific details, or with other methods, components, materials, etc. In other cases, known structures, materials or operations are not shown or described in detail to avoid obscuring various aspects of the embodiments. The reference to an embodiment in the context of this description indicates that a particular configuration, structure or characteristic described in relation to the embodiment is included in at least one embodiment. Therefore, phrases such as in an embodiment, possibly present in different places of this description do not necessarily refer to the same embodiment. Moreover, particular configurations, structures or characteristics may be combined in any convenient way in one or more embodiments.

[0039] The word exemplary or exemplifies is used herein to mean serving as an example, instance, or illustration. Any embodiment or design described herein as exemplary is not necessarily to be construed as preferred or advantageous over other embodiments or designs.

[0040] The references used here are only for convenience and do not therefore define the field of protection or the scope of the embodiments.

[0041] FIGS. 1-5 referin generalto the production of lighting devices of the type suitable for use with electrically-powered light radiation sources (for example, solid state light radiation sources, such as LED sources) arranged on a ribbon-like support structure 10, optionally flexible.

[0042] For present purposes, such a structure 10 may be considered to have an indefinite length, of which a particular portion or segment is represented in the figures.

[0043] One or more embodiments may benefit from the possibility of subdividing the structure 10 by segmenting it or cutting it to length according to the requirements of application and use.

[0044] In one or more embodiments, the structure 10 may comprise a ribbon-like substrate 12, for example, of an electrically-insulating material, substantially similar to a substrate for Printed Circuit Boards (PCB) of a flexible type (Flexible PCB or FPCB).

[0045] In one or more embodiments, the substrate 12 may comprise materials such as polyimidePI, polyethylene naphthalate, PEN, polyethyleneiminePEI, ultra-thin glass.

[0046] One or more embodiments, as exemplified in FIG. 1, envisage carrying out a screen printing operation on the substrate 12, which forms a pattern of electrically-conductive lines 14 on a surface of the substrate 12.

[0047] In one or more embodiments, the screen printing may use electrically-conductive ink (for example, polymeric ink for thick film printingPolymer Thick FilmPTF) containing a dispersion of electrically-conductive material such as, for example, (nano)particles of silver and/or copper.

[0048] The screen printing forms a series of successive printed images 16, represented in FIGS. 1, 3 and 5 by respective rectangles with dashed lines, which follow one another in the longitudinal direction of the substrate 12. The printed images 16 may comprise respective electrically-conductive lines 14 arranged according to a predetermined pattern. The successive printed images 16 may follow one another along the longitudinal axis of the substrate 12 with the same repeated pattern.

[0049] In one or more embodiments, the electrically-conductive lines 14 may comprise longitudinal lines 14, which may extend continuously over the length of the structure 10 (for example, with a bus function) and connection areas 14 intended to provide an electric conduction function locally in relation to the light radiation sources.

[0050] Again, FIGS. 1-5 refer, purely by way of example, therefore without limiting the scope of the embodimentsto a process aimed at producing, within the ribbon-like structure 10, a certain number of ribbon-like modules 10.sub.1, 10.sub.2, . . . 10.sub.6 (the reference to a number of modules equal to six is merely an example, as these modules may be any number, ideally from 1 to N) initially formed as a single structure and then intended to be separatedoperating in a known wayso as to give rise to individual ribbon-like modules usable for producing respective LED modules.

[0051] The following part of the present description will, therefore, refer to the structure 10 as a whole, being understood that the operations exemplified with reference to the structure 10 may be carried out with reference to each and every one of the modules 10.sub.1, 10.sub.2, . . . , 10.sub.6 included therein.

[0052] In one or more embodiments, the printed images 16 are spaced apart from each other in the longitudinal direction of the substrate 12 by the separation gaps G. The separation gaps G form an offset distance in the order of a few millimeters between consecutive printing images. The separation gaps G may make it easier to avoid possible problems related to tolerance factors and possible smearing of the electrically-conductive ink during the screen printing process.

[0053] As shown in FIG. 2, at the end of the screen printing, the electrically-conductive lines 14 of the successive printed images 16 are spaced apart from each other by separation gaps G and are devoid of mutual electrical connections. In one or more embodiments the separation gaps G may be provided between mutually facing ends of bus lines 14 of adjacent printed images 16.

[0054] In one or more embodiments, it is possible to provide an electrical continuity between the electrically conductive lines 14 of successive printed images 16. In one or more embodiments, the electrical continuity between the electrically conductive lines 14 of successive printed images 16 may be achieved by forming ink jumpers 18 that extend through the separation gaps G.

[0055] As exemplified in FIG. 4, in one or more embodiments the ink jumpers 18 may be formed by delivering electrically-conductive ink by inkjet printing.

[0056] In one or more embodiments, the ink jumpers 18 may connect facing ends of respective bus lines 14 of adjacent printed images 16 to each other. The interconnection between the bus lines 14 of two consecutive printed images 16 may be very short, for example, a few millimeters, which results in a short printing time.

[0057] In one or more embodiments, the electrically-conductive ink forming the ink jumpers 18 may be dispensed at an inkjet printing station including one or more nozzles 19, located downstream of a screen printing station.

[0058] In one or more embodiments, the nozzle 19 is not in contact with the ink applied by means of screen printing, so as to avoid smearing.

[0059] In one or more embodiments, the nozzle 10 of the inkjet printing station may deliver the ink forming the ink jumpers 18 onto a three-dimensional surface, for example, on the upper surfaces of the bus lines 14 and on the uncovered support 12, in a single process step.

[0060] In one or more embodiments, the inkjet printing that forms the ink jumpers 18 may be carried out prior to the curing of the ink applied by screen printing.

[0061] In one or more embodiments, the curing of the ink may be carried out after the screen printing and the formation of the ink jumpers, for example, in an oven unit located downstream of the screen printing station and the inkjet printing station.

[0062] As exemplified in FIG. 5, the manufacturing method of the structure 10 may comprise applying electrically-powered light radiation sources 20, e.g. LED sources to the electrically-conductive lines 14 after curing the electrically-conductive ink. In one or more embodiments, the electrically-powered light radiation sources 20 may be mounted on the support structure 10 using known assembly techniques (for example, SMT techniques).

[0063] In one or more embodiments, the operations that lead to producing the support structure 10 may be carried out in a reel-to-reel process, which may envisage the continuous unwinding of the substrate 12 from a first reel, and continuously collecting the finished support structure 10 in a second reel at the end of the process.

[0064] One or more embodiments may, therefore, provide a method for forming support structures (e.g. 10) for electrically-powered lighting devices, comprising: providing an electrically insulating ribbon-like substrate (e.g. 12), forming electrically-conductive lines (e.g. 14) on a surface of the substrate (e.g. 12) by screen printing of electrically-conductive ink, the screen printing comprising printing a plurality of repeated printed images (e.g. 16), which follow one another along a longitudinal direction and are separated from each other by separation gaps (e.g. G), and forming electrically-conductive ink jumpers (e.g. 18) that extend through the separation gaps (e.g. G) and which provide electrical continuity between electrically-conductive lines (e.g. 14) of adjacent printed images (e.g. 16), wherein forming ink jumpers (e.g. 18) comprises delivering electrically-conductive ink by inkjet printing.

[0065] In one or more embodiments, the method may envisage curing the electrically-conductive ink after screen printing and forming the ink jumpers (e.g. 18).

[0066] In one or more embodiments, the ink jumpers (e.g. 18) may connect facing ends of respective bus lines 14 of adjacent printed images (e.g. 16) to each other.

[0067] In one or more embodiments, delivering electrically-conductive ink by inkjet printing may comprise injecting electrically-conductive ink by means of at least one nozzle (e.g. 19) not in contact with the electrically-conductive ink applied by means of screen printing.

[0068] In one or more embodiments, the method may comprise applying electrically-powered light radiation sources (e.g. 20) to the electrically-conductive lines (e.g. 14) after curing the electrically-conductive ink.

[0069] In one or more embodiments, the method may comprise providing the ribbon-like substrate (e.g. 12) as a reel, and screen printing the electrically-conductive ink onto the ribbon-like substrate (e.g. 12) in a reel-to-reel process.

[0070] In one or more embodiments, the method may comprise dividing the support structure (e.g. 10) into a plurality of ribbon-like modules (e.g. 10.sub.1, . . . , 10.sub.6) co-extending along the direction of the length of the support structure (e.g. 10).

[0071] In one or more embodiments, a lighting device may comprise: a support structure (for example, 10) produced according to one or more embodiments, and electrically-powered light radiation sources (e.g. 20) arranged on the support structure (e.g. 10) with the light radiation sources (e.g. 20) electrically coupled to the electrically-conductive lines (e.g. 14).

[0072] In one or more embodiments: the electrically-powered light radiation sources may comprise LED sources (20), and/or the electrically-powered light radiation sources (e.g. 20) may be mounted onto the support structure (e.g. 10) with SMT technology.

[0073] Without prejudice to the underlying principles of the invention, the details of implementation and the embodiments may vary, even significantly, with respect to those illustrated here, purely by way of non-limiting example, without departing from the scope of the invention.

[0074] While specific aspects have been described, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the aspects of this disclosure as defined by the appended claims. The scope is thus indicated by the appended claims and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced.

LIST OF REFERENCE SIGNS

[0075] support structure 10

[0076] ribbon-like substrate 12

[0077] electrically-conductive lines 14

[0078] printed images 16

[0079] longitudinal lines 14

[0080] connection areas 14

[0081] ribbon-like modules 10.sub.1, 10.sub.2, . . . , 10.sub.6

[0082] separation gaps

[0083] ink jumpers 18

[0084] nozzles 19

[0085] light radiation sources 20