Abstract:
The present invention concerns a light emitting diode display device. A plurality of pieces of long printed circuit board, several copper foil lines being etched, are erected. A plurality of led lamps straddle over the perimeter of each printed circuit board by means of soldering each led lamp&#39;s pin terminals on copper foil lines and copper wire, and which are integrated into a display device. After connected with a drive circuit, the display device may display texts or images with the drive voltage.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a light emitting diode display device. More specifically, the present invention is directed to numerous light emitting diode (LED) lamps which straddle or side over the edges of numerous long printed circuit boards (PCBs), the pins of LED lamps being soldered to the copper foillayer as they touch, or being soldered to thick copper wires to integrate into a LED display unit.  
       BACKGROUND  
       [0002]     The previous technology of LED display panel is comprised of numerous small panels. For example, C/A-5880 8×8 dot matrix display from Taiwan PARA Company adopts a common anod matrix LED display panel, wherein anodes of all LEDs in the same row are connected to row electrode and cathodes of all LEDs in the same column are connected to column electrode so that the images and texts are displayed on one side with monocolor. Due to the overall chip glue, the thickness can reach 0.35 inch. Additionally, the appearance size and the display principle of a multicolor LED display panel are identical to the said monocolor one. However, two or three different LED chips are disposed at each pixel luminous point. The previous LED display panel can only display texts and images on single surface. The construction for installation of such information board is tough and expensive. In case there has some fault at the pixel luminous point of the previous LED device, it is impossible to replace LED at such defective pixel luminous point. Additionally, the previous device can only perform the plane display, but not for the bend plane display. Hereby, for above limitations, single-surface or double-surface LED display device is developed, characteristically of low cost, easy elimination of failures and convenient construction.  
       SUMMARY  
       [0003]     The present invention is to adopt a plurality of pieces of long printed circuit boards (PCBs) with proper width and flexibility, each long PCB&#39;s copper foillayer being etched into copper foil tapes, lines or rectangles. Numerous LED lamps straddle over or side over the edges of long PCBs, and which pins at different surfaces means straddling, at the same surface means siding. LED lamp pins are connected with and soldered to the copper foil. Integrating said numerous LED lamps mounted on said multiple long PCBs are shaped into a LED dot matrix array, texts, figures or images. With dot matrix array, the LED display device adopts upright and parallel arrangement of the faces of multiple long PCBs (assume m pieces) which copper foillayers etched into line shape, tape shape or rectangle shape. Multiple LED lamps (assume n lamps) straddle or side over the edges of upright long PCBs. Each LED lamp pins are soldered to the copper foil surface which the said pins are contiguous, so that n LED lamps are lined in columns. Therefore, m×n LED lamps are rowed in dot matrix. Column electrode is produced on each PCB with long thin copper foil tapes. LED lamps in the same column of m×n LED lamps solder with the identical property LED lamp pins to generate the column electrode. The long thin metal rod (thick rod wire) to generate the row electrodes are soldered to the copper foil, transferred to the long thin copper foil of PCB so that row and column electrodes are lined parallelly. In this way, it can be connected with the drive circuit easily. One-surface copper foillayer or double-surface copper foillayer are selected for long PCBs, the monocolor luminescence or the two fundamental colors luminescence selected for LED lamps. The monocolor LED lamp with anode-cathode pins is installed on long PCB, 2 pins soldered in siding way at the same side or in straddling way at two sides. And the two fundamental colors LED lamp with 3 pins is installed on PCB, 3 pins soldered in siding way preferential. The driving method of each LED lamp is identical to the commercial LED dot matrix array panel in the prior art as follows: separate and periodic scan for all row electrodes (or column electrodes) to select the voltage. Additionally, all column electrodes (or row electrodes) are transferred to the potential signals to display texts, images and figures corresponding to LED lamp lightup, then integrated with the said time division scan. Hereby, the present invention can address any LED lamp to display any text and image. Numerous pixels are produced from the cross of row and column electrodes of long thin metal rods and the said long PCBs. A single-surface display device is developed with the single-edge installation of LED lamps and a double-surface display device is developed with the double-edge installation of LED lamps. In case specific text and image are required, then LED lamp is installed at partial pixel points. Furthermore, long PCBs may be bent in words or patterns due to its proper width and excellent reelability. Numerous LED lamps straddle over the edges of PCB, LED lamp pins connected with and soldered to the surface of the copper foil. Finally, the device may display texts and images with the drive voltage. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0004]      FIG. 1 (A) is a stereogram view, a planform view, a side elevation view and equivalent circuit diagram of the monocolor LED lamp with 2 pins shaped in cube;  
         [0005]      FIG. 1 (B) is a planform view, side elevation view and equivalent circuit diagram of the two fundamental colors LED lamp with 2 pins shaped in cube;  
         [0006]      FIG. 1 (C) is a planform view, side elevation view and equivalent circuit diagram of the two fundamental colors LED lamp with 3 pins shaped in cube;  
         [0007]      FIG. 1 (D) is a planform view, 2 side elevation views and equivalent circuit diagram of LED Light Bar with 2 pins shaped in cube;  
         [0008]     FIGS.  2 (A)  2 (B)  2 (C)  2 (D) are a stereogram view, planform views, side elevation views and equivalent circuit diagrams of the monocolor LED lamp with 2 pins, the two fundamental colors LED lamp with 2 pins and 3 pins, and the three fundamental colors LED lamp with 4 pins, which all are shaped in cylinder;  
         [0009]      FIG. 3  is a schematic plan view of the monocolor LED lamps mounted on partial pixel points shaped in “LEE”;  
         [0010]      FIG. 4  is a schematic plan view of the monocolor LED lamps mounted all partial pixel points shaped in LED dot matrix array;  
         [0011]      FIG. 5  is a perspective view of LED dot matrix array;  
         [0012]      FIG. 6  is a perspective view of LED dot matrix array for assembling;  
         [0013]      FIG. 7  is a perspective view of LED dot matrix array in reversed side;  
         [0014]     FIGS.  8 (A)  8 (B) are an assembly stereogram and an equivalent circuit diagram of single-surface monocolor display of another embodiment;  
         [0015]     FIGS.  9 (A)  9 (B) are an assembly stereogram and an equivalent circuit diagram of the embodiment for double-surface monocolor display;  
         [0016]      FIG. 10  is a perspective view for assembly of the first embodiment for single-surface two fundamental colors display;  
         [0017]      FIG. 11  is a perspective view for assembly of the second embodiment for single-surface two fundamental colors display;  
         [0018]      FIG. 12  is a perspective view for assembly of the embodiment for double-surface two fundamental colors display;  
         [0019]      FIG. 13  is an equivalent circuit of the embodiment shown in  FIG. 12 ;  
         [0020]      FIG. 14  is timing diagram of the drive voltage to drive the equivalent circuit shown in  FIG. 13 ;  
         [0021]      FIG. 15  is a stereogram view of the embodiment for the curved surface monocolor display;  
         [0022]      FIG. 16  is a stereogram view of the first embodiment for display of the fixed text;  
         [0023]      FIG. 17  is an equivalent circuit diagram of the first embodiment for display of the fixed text;  
         [0024]      FIG. 18  is the timing diagram to drive the equivalent circuit of the first embodiment for display of the fixed text;  
         [0025]      FIG. 19  is a schematic plan view of the second embodiment for display of the fixed text shaped “US”;  
         [0026]      FIG. 20  is an equivalent circuit diagram of the second embodiment for display of the fixed text shaped “US”;  
         [0027]      FIG. 21  is an assembly stereogram view of the second embodiment for display of the fixed text shaped “US”;  
         [0028]      FIG. 22  is a stereogram view of the third embodiment for display of the fixed words shaped in “OPEN”;  
         [0029]      FIG. 23  is an assembly stereogram view of the third embodiment for display of the fixed words shaped in “OPEN”;  
         [0030]      FIG. 24  is a stereogram view of the fourth embodiment for display of the fixed words in “OPEN”;  
         [0031]      FIGS. 25, 26  and  27  are a planform, a partial stereogram and an equivalent circuit diagram of the embodiment for display of the fixed word of “TW” with dot matrix voltage driving;  
         [0032]      FIG. 28  is a stereogram view of a first baton of the embodiment;  
         [0033]      FIG. 29 (A) is a stereogram view of a second baton of the embodiment;  
         [0034]      FIG. 29 (B) is a stereogram view of the second baton of the embodiment for lightup and display;  
         [0035]      FIG. 30 (A) is a stereogram view of a third baton of the embodiment;  
         [0036]      FIG. 30 (B)  30 (C) are two stereogram views of the third baton of the embodiment for part LED lamps lightup and all LED lamps lightup. 
     
    
     DESCRIPTION  
       [0037]     The LED lamp in the present invention is LED lamp or LED LIGHT BAR. Please refer to FIGS.  1 (A),  1 (B),  1 (C) and  1 (D) for those shaped in 6-face cuboid or cube.  FIG. 1 (A) shows a stereogram view, planform view, side elevation view and equivalent circuit diagram of the monocolor LED lamp with 2 pins,  FIG. 1 (B) representing a planform view, side elevation view and equivalent circuit diagram of the two fundamental colors LED lamp with 2 pins,  FIG. 1 (C) relating to a planform view, side elevation view and equivalent circuit diagram of the two fundamental colors LED lamp with 3 pins and  FIG. 1 (D) relating to a planform view, side elevation view, another side elevation view, luminescent area planform view and equivalent circuit diagram of LED Light Bar. FIGS.  2 (A), 2 (B), 2 (C) and  2 (D) show a front elevation view, side elevation view and equivalent circuit diagram of LED lamps for those shaped in cylinder, LED lamps with 2 pins in  FIG. 2 (A) and  2 (B), the monocolor LED lamp in  FIG. 2 (A) and the two fundamental colors (RY) LED lamp with 2 pins in  FIG. 2 (B). All embodiments of the monocolor LED lamps with 2 pins of the present invention can be improved as the two fundamental colors LED lamps in  FIG. 2 (B) with the driving circuit to develop into multiple colors display.  FIG. 2 (C) relates to the two fundamental colors (RG) LED lamps with 3 pins and  FIG. 2 (D) relates to the three fundamental colors (RGB) LED lamps with 4 pins. In accordance with the cross between multiple column electrodes and multiple row electrodes and the installation method of LED lamps at numerous pixel points, the embodiments vary with the difference of the voltage driving method.  FIG. 3  relates to a plan view of the monocolor LED lamps mounted on partial pixel points and  FIG. 4  shows a plan view of the monocolor LED lamp mounted on all pixel points. Partial installation of the monocolor LED lamp in  FIG. 3  displays an English word of “Lee”. Besides, drive circuit  60  adopts the addressing and selection method of the dot matrix array of LED lamp, the long PCB  72 , the shape of copper foil in PCBs and the installation method of LED lamp  12  are identical. Based on all installations, the description in details is provided with drawings as follows:  FIG. 5  is a perspective view of LED dot matrix array;  FIG. 6  is a perspective view of LED dot matrix array for assembling and  FIG. 7  is a perspective view of LED dot matrix array in reversed side. Numerous long PCBs  72  insert into frame  80  vertically, pole  820  inserted into eyelet  805  with 3 screws  811  fixing. The long PCBs  72  are provided with single-surface copper foillayer, the copper foillayer hereof etched into long copper foil tape  753  and short copper foil tape  754 , all LED lamps straddling over each long PCB  72  and numerous LED lamps  12  straddling over edges of long PCB  72 , cathode pin  112  connected with and soldered to long copper foil tape  753 . Hereby, long copper foil tapes  753  of each long PCB  72  generate column electrode Y 1 , Y 2  and Y 3 , etc, while anode pins  111 ,  211 , etc are placed at the side of the copper foil free of long PCB  72 , all the LED lamps arranged in the first column which anode pins  111  are soldered to thick copper wire  701  to generate row electrode X 1 , thick copper wire  701  with thin copper wire  901  threaded into eyelet  806  on long PCB  721 , then soldered to short copper foil tape  754  so that row electrode X 1  is transferred to short copper foil tape  754 , all row and column electrodes connected by long and short copper foil tape  753  and  754 , then connected to the drive circuit  60  by electric wire  30 .  FIG. 8 (A) is an assembly stereogram view of single-surface monocolor display of another embodiment and  FIG. 8 (B) relates to an equivalent circuit diagram of single-surface monocolor display of the embodiment. Both surfaces of long PCB  72  are embedded with copper foil, multiple copper foil rectangles  755  lined at one surface and multiple comb copper foils  760  provided at another surface, each copper foil rectangle  755  punctured with a eyelet  806 , 4 long PCBs of PCB  721 ,  722 ,  723  and  724  installed with numerous LED lamps  12  and lined parallelly, the long PCB  721  moved right to close to other three long PCBs with dot matrix array, LED lamps  12  straddling over long PCB  72 , cathode pin  112  soldered to copper foil rectangle  755  and anode pin  111  soldered to comb-shaped copper foil  760 . Numerous thick copper wires  70  are threaded into eyelets  806  on copper foil rectangle  755  in the same row, soldered to copper foil rectangle  755 . The function of thick copper wires  701  is to transfer copper foil  758  of row electrode X 1  in long PCB  721  to the column direction, while the function of thick copper wires  702  is to transfer copper foil  758  of row electrode X 2  in long PCB  722  to the column direction, the others on the analogy of this.  FIG. 9 (A) relates to an assembly stereogram view of the embodiment for double-surface monocolor display and  FIG. 9 (B) shows a equivalent circuit diagram of the embodiment for double-surface monocolor display. The long PCBs  72  are provided with double-surface copper foil, four PCBs of PCB  721 ,  722 ,  723  and  724  lined vertically, copper foil rectangles  755  lined in pairs at the left side with eyelet  806  and the dendritic-shaped copper foil  756  provided at right side. LED lamps  12  are installed at the front side and LED lamps  12   b  are installed at the back side, all of which straddling over the edges of long PCBs  72 . Cathode pin  112  at the left side of long PCBs  72  is placed in and soldered to copper foil rectangle  755 , while anode pins  111  at the front and back side of LED lamps  12  and  12   b  in the same row are at the right side. Dendritic-shaped copper foils  756  are soldered in proper place to generate column electrode, such as, column electrode Y 5  of long PCB  725  as seen in the  FIG. 9 (A). Thick copper wire  701  is threaded into eyelet  806  of copper foil rectangle  755  to connect with cathode pin  112  of the front LED lamp  12  at the front row, then soldered to generate row electrode X 1  in the front. Then it is transferred to the column direction through copper foil line  758  of long PCB  721 , the drive circuit (without marking out) connected by electric wire  30 . row electrode X 1   b  is connected by thick copper wire  702  with cathode pin of LED lamps  12   b  installed at back side in the first row.  FIG. 10  relates to a perspective view for assembly of the first embodiment for single-surface two fundamental colors display. LED lamps  12  is provided with 3 pins for 2 fundamental colors common anode display with red and green. 3 pins are placed at the same surface of long PCB  72 , siding over the edges of long PCB  72 , such as LED lamps  64  siding over long PCB  724 , red cathode pin  641  and green cathode pin  643  thereof connected with and soldered to copper foil rectangle  755 , common anode pin  642  bent and threaded into eyelet  807  to copper foil tape  759  at the back side, then soldered (i.e. long PCB  725  shown in  FIG. 10  ), each copper foil tape  759  to generate column electrode Y 1 , Y 2  and Y 3 , etc (no marking out). Thick copper wire  70  is threaded into the eyelet  806  of the red cathode pin or the green cathode pin in the same row of each copper foil rectangle  755 , then soldered to generate the red row electrode or the green row electrode X 1 R, X 1 G, X 2 R and X 2 G, etc, then it is connected in the column direction by copper foil lines  758 , such as the red row electrode X 1 R and the green row electrode X 1 G connected by copper foil wire  758  of long PCB  721  and the red row electrode X 2 R and the green row electrode X 2 G connected by copper foil wire  758  of long PCB  722 , the others on the analogy of this.  FIG. 11  relates to a perspective view for assembly of the second embodiment for single-surface two fundamental colors display. The difference between this embodiment and the first embodiment in  FIG. 10  is long PCBs  72  with single-surface copper foil and LED lamp  12  is the two fundamental colors display resulting in 3 copper foil rectangles  755  must be provided with 3 pins. Each long PCB  72  provides 3 copper foil tapes  758 , one for column electrode, one for row red electrode and the other for green row electrode. Jumper wires  780  and  781  must be provided. Please refer to  FIG. 12  is a perspective view for assembly of the embodiment for double-surface two fundamental colors display, LED lamps  12  and  12   b  at the front and back sides with 3 pins for the two fundamental colors common anode of red and green siding over the edges of long PCBs  72 . The red cathode pin of LED lamps  12  at the front side in the first row is connected by thick copper wire  701  and the red cathode pin of LED lamp  12   b  at the back side in the first row connected by the thick copper wire  702 , then transferred by copper foil line  758  of long PCB  721  to the red row electrode X 1 R. In the same column and at the same surface of each long PCB, the common anode pin of LED lamps appears. After threading into the eyelet of PCB  72  and soldered to copper foil tape  759 , the column electrode is generated, such as 2 copper foil tapes  759  on the long PCB  726  for Y 6  and Y 6   b,  as seen in  FIG. 12 .  FIG. 13  shows an equivalent circuit of the embodiment, LED lamps  11 ,  21  and  31  for display of the first column at the front side and LED lamps  11   b,    21   b  and  31   b  for display of the first column at the back side, the others on the analogy of this. LED lamps installed in the same row and side are connected with the red cathode pin to generate the red row electrode X 1 R, X 2 R and X 3 R, etc and connected with the green cathode pin to generate green row electrode X 1 G, X 2 G and X 3 G, etc. With proper drive signal, the luminescence color of each LED lamp can be selected for the red or green. Please refer to  FIG. 14  for timing diagram of the drive voltage. clk is the frequency wave signal. every k cycles is a time period (T). The interior cycles are named with Ts 1 , Ts 2  . . . Tsk. Within every time period (T), the column electrode Y 1  can reach high potential (H) only at Ts 1  and the column electrode Y 1   b  can reach high potential (H) only at Ts 2  and the column electrode Y 2  can reach high potential (H) at Ts 3 , the others on the analogy of this. Within every time period (T), H or L of the interior row electrode X 1 R and X 1 G at Ts 1  drive LED lamp  11  at the front side in red, green, orange or off (L refer to lightup) due to the transient phenomena of the human eyes, and H or L at Ts 2  drive LED Lamp  11   b  at the back side in red, green, orange or off (L refer to lightup), the others on the analogy of this. Through observation of the timing voltage of the row electrode X 1 R and X 1 G, provided that are H during Ts 1  within every time period (T), LED lamps at the front side are off, and if X 1 R and X 1 G are L during Ts 2  within every time period (T), the two fundamental colors of the red and green for LED lamps  11   b  at the back side are on to display in orange. Within every time period (T), X 1 R is L at Ts 3 , and H at X 1 G, and the red chip of LED Lamp  12  at the front side is on to display in red. Refer to  FIG. 15  for a stereogram view of the embodiment for the curved side monocolor display. It adopts multiple arcing ring Printed Circuit Boards  73  (referred to as arcing ring PCB  73 ) with double surface copper foil so that the faces are arranged parallelly with equal distance. Multiple copper foil rectangles  755  are soldered to anode pins  111  of LED lamps  12  at one surface. At another surface, the copper foil tapes are soldered to the cathode pins of LED lamps  12  to generate the column electrode (no marking out). Each thick copper wire  70  is threaded into the eyelet of copper foil rectangle  755  in the same column and then soldered to produce column electrodes Y 1 , Y 2  . . . Y 25 , etc. The row and column electrodes are generated with the drive circuit  60  by electric wire  30 . Applying the dot matrix voltage driving signals, it can address and select any LED lamp for lightup and display. Please refer to  FIG. 16  for a stereogram view of the first embodiment for display of the fixed text. It adopts multiple long PCBs  72  with copper foil lines  759  being etched in double surfaces, the surfaces upright and parallel and fastened to frame  80 , multiple LED lamps  12  straddling over long PCB  72  as the shape of letter of “Lee”. Anode pins  111  of LED lamps  12  in the same column straddling over the copper foil line  759  at the left surface of long PCBs  72  and soldered to fasten and connect, in order to produce the electrode, such as Y 1 , Y 2 , Y 3  . . . Y 22 , etc, cathode pins in the same row straddling over the copper foil line at the right surface (no marking out), then electric wire  30  adopted to connect and solder to generate column electrode Y 23 , connected to the common reference potential of square wave  61  (earthing), which provides the periodic square wave drive voltage for each column electrode of Y 1 , Y 2 , Y 3  . . . Y 22 , etc. Please refer to  FIG. 18  for the voltage timing diagram to drive the equivalent circuit diagram of the first embodiment for display of the fixed text shown in  FIG. 17 . The word of “Lee” is transformed to 22 rows and the lamps are on orderly from left to right till all lamps are on recurrently.  FIG. 19  shows planform view of the second embodiment for display of the fixed text.  FIG. 20  is an equivalent circuit diagram of the second embodiment for display of the fixed text.  FIG. 21  is an assembly stereogram view of the second embodiment for display of the fixed text, the long PCBs  72  with double surface copper foil lines  759  bent and curved into 2 English letters of “US” along the clearance between 2 fixing poles  808 , thickness and excellent winding, LED lamps  12  straddling over U-shaped long PCB  721  and its anode pins  111  soldered to copper foil lines  759 , connected to generate electrode Y 1 . For S-shaped LED lamps  12 , anode pins  111  are soldered to copper foil lines  759 , connected to generate electrode Y 2 . For US-shaped LED lamps  12 , anode pins  112  are soldered to copper foil lines  761  and  762 , connected to generate electrode Y 3  for the common reference potential (earthing). With periodic square wave for electrodes Y 1  and Y 2 , the letters of U and S are flashing or on or off at the same time.  FIG. 22  is a stereogram view of the third embodiment for display of the fixed words.  FIG. 23  is an assembly stereogram view of the third embodiment for display of the fixed words, copper foil line  759  are embedded in numerous long PCBs  72  at both surfaces to form “OPEN”, among which, “O” is shaped by bending the long PCB  726 , “P” shaped by puncture of 2 eyelets on long PCB  727  and bending two ends of long PCB  728 , then inserted into 2 rabbets, “E” shaped by the rabbets of the long PCBs  730 ,  731  and  732  inserted into three eyelets on long PCB  729 , then soldered to the copper foil face at the eyelet, and “N” shaped by three long PCBs  733 ,  734  and  735  and 2 V-shaped copper sheets  770  and  771  soldered in the retained copper foil area, such as V-shaped copper sheets  771  soldered to the copper foil rectangles  780  and  781 . Four letters of “OPEN” are fixed on platform  81  with the bar coppers  822  soldering the copper foil lines  759  of long PCBs.  FIG. 24  is a stereogram view of the fourth embodiment for display of the fixed words, the sloping line of Letter “N” in “OPEN” composed of 2 bare copper wires  33  soldered to several LED lamps  12 . Please refer to  FIG. 25, 26  and  27  for a planform, a partial stereogram view and an equivalent circuit diagram of the embodiment for display of the fixed word of “TW” with dot matrix voltage. “LED” lamps used are monocolor luminescences with 2 LED chips. For Letter “T”, adopt two long PCBs  721  and  722 , Letter “W” adopting 4 long PCBs. The anode pins  121  of LED lamp  21  to  27  are soldered to the copper foil tape  759  to generate the row electrode X 2  and LED lamp  11  is soldered to the anode pin of LED lamp  17  to generate the row electrode X 1 . The anode pin  113  of 14 LED lamps are soldered to the copper foil rectangle  755  with electric wire  30  and screws  811  to generate 7 colunm electrodes of Y 1 , Y 2  . . . Y 7 . The row and column electrodes are connected with the drive circuit  60  with the dot matrix drive voltage signal to address and select any LED lamp for lightup and display.  FIG. 28  shows a stereogram of a baton of the embodiment, characteristically of numerous LED lamps  12  straddled over and soldered to the long PCB  721  to form a straight segment. Then the Handle  38  is provided with the drive circuit.  FIG. 29 (A) relates to numerous LED lamps  12  installed at the front and back edges of PCB  721 . And  FIG. 29 (B) shows a stereogram view of the second baton of the embodiment for lightup and display.  FIG. 30 (A) relates to numerous LED lamps  12  installed at 2 long PCBs  721  and  722  for double straight segments. And  FIG. 30 (B) shows a stereogram view of the third baton of the embodiment for lightup and display.  FIG. 30 (C) relates to a stereogram of the third baton of the embodiment for all lamps lightup and display. The common part of “electric wire  30 ” in above each figure is covered with the insulation layer to connect other parts through soldering or winding. The pins of LED lamps and the thick copper wire  70  are contiguous to the copper foillayer are connected through soldering with soft soldering for the copper foil. It is difficult to mark with icon, therefore all of them are described with words.