Patent Publication Number: US-2023155055-A1

Title: Method of manufacturing display module with light emitting diode free of a split-screen boundary line and display module with light emitting diode

Description:
FIELD 
     The subject matter herein generally relates to display modules, in particular to a display module with light emitting diodes and a method of manufacturing the same. 
     BACKGROUND 
     A liquid crystal display (LCD) with mini LEDs as backlighting is better than a LCD display with ordinary LEDs, in terms of brightness, contrast ratio, and color restoration. However, the brightness uniformity of the display screen with mini LEDs is poor, and erratic display may occur. In addition, when a single large display screen is split into two display screens, the mini LEDS may form a black line at the division of the screen. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Implementations of the present technology will now be described, by way of embodiment, with reference to the attached figures. 
         FIG.  1    is a cross-sectional view of an embodiment of a copper clad laminate according to the present disclosure. 
         FIG.  2    is a cross-sectional view showing a first blind hole formed on the copper clad laminate of  FIG.  1   . 
         FIG.  3    is a cross-sectional view showing a copper plating layer formed on a second copper foil of the copper clad laminate of  FIG.  2   . 
         FIG.  4    is a cross-sectional view showing a first copper foil and a second copper foil of the copper clad laminate of  FIG.  3    being etched to form a first conductive wiring layer and a second conductive wiring layer. 
         FIG.  5    is a cross-sectional view showing a first cover film formed on the second conductive wiring layer of  FIG.  4   . 
         FIG.  6    is a cross-sectional view showing photosensitive ink layer formed on the first conductive wiring layer of  FIG.  5   . 
         FIG.  7    is a cross-sectional view showing the photosensitive ink layer of  FIG.  6    subjected to exposure to form a photosensitive midbody. 
         FIG.  8    is a cross-sectional view showing an uncured portion of the photosensitive midbody on the first conductive wiring layer of  FIG.  7    being removed. 
         FIG.  9    is a cross-sectional view showing the photosensitive ink layer in a first gap of  FIG.  8    subjected to exposure. 
         FIG.  10    is a cross-sectional view showing a first surface treatment layer and a third surface treatment layer respectively formed on a first pad and a third pad of  FIG.  9   . 
         FIG.  11    is a cross-sectional view showing an embodiment of a second circuit substrate. 
         FIG.  12    is a cross-sectional view showing an embodiment of a first heat conductive adhesive and a heat dissipation plate. 
         FIG.  13    is a cross-sectional view showing the first circuit substrate of  FIG.  10    and the second circuit substrate of  FIG.  11    being bond to the heat dissipation plate through the first heat conductive adhesive of  FIG.  12   . 
         FIG.  14    is a cross-sectional view showing a plurality of light emitting diodes arranged on the first conductive wiring layer and the third conductive wiring layer of  FIG.  13   . 
         FIG.  15    is a cross-sectional view showing an embodiment of a display module. 
     
    
    
     DETAILED DESCRIPTION 
     Implementations of the disclosure will now be described, by way of embodiments only, with reference to the drawings. The disclosure is illustrative only, and changes may be made in the detail within the principles of the present disclosure. It will, therefore, be appreciated that the embodiments may be modified within the scope of the claims. 
     Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The technical terms used herein are to provide a thorough understanding of the embodiments described herein, but are not to be considered as limiting the scope of the embodiments. 
     A method of manufacturing a display module with light emitting diodes is provided by way of example, as there are a variety of ways to carry out the method. The method can begin at step  11 . 
     At step  11 , referring to  FIG.  1   , a copper clad laminate  10  is provided. 
     The copper clad laminate  10  includes a first base layer  101  having two opposite surfaces each with a copper foil layer, being first copper foil layer  102  and second copper foil layer  103 . 
     The first base layer  101  is made of a resin which may be selected from a group consisting of epoxy resin, polypropylene, polyphenylene oxide, polyimide, polyethylene terephthalate, polyethylene naphthalate, and any combination thereof. In one embodiment, the first base layer  101  is made of polyimide. 
     It is to be noted, in some embodiments, the first base layer  101  may be provided with a plurality of conductive wiring layers (not shown) therein. 
     At step  12 , referring to  FIG.  2   , a plurality of first blind holes  11  are defined on the copper clad laminate  10 . 
     Each of the first blind holes  11  penetrates the second copper foil layer  103  and the first base layer  101 , and portions of the first copper foil layer  102  are exposed in the first blind holes  11 . 
     At step  13 , referring to  FIG.  3   , the second copper foil layer  103  is plated with copper to form a copper plating layer  104 . The process of copper plating infills copper into the first blind holes  11  to form first heat conductive portions  12 . 
     At step  14 , referring to  FIG.  4   , the first copper foil layer  102  is etched to form a first conductive wiring layer  20 , and the second copper foil layer  103  is etched to form a second conductive wiring layer  21 . 
     The first conductive wiring layer  20  includes a plurality of first pads  201 , and the second conductive wiring layer  21  includes a plurality of third pads  211 . First gaps  202  are formed in the first conductive wiring layer  20 , and two adjacent first pads  201  are separated from each other by one first gap  202 . Third gaps  212  are formed in the second conductive wiring layer  21 , and two adjacent third pads  211  are separated from each other by one third gap  212 . 
     The first conductive wiring layer  20  can be thermally conductive with the second conductive wiring layer  21  through the first heat conductive portions  12 . In addition, the first conductive wiring layer  20  can also be electrically connected to the second conductive wiring layer  21  through the first heat conductive portions  12 . 
     At step  15 , referring to  FIG.  5   , a first cover film  30  is formed on the second conductive wiring layer  21 . 
     The first cover film  30  includes a first adhesive layer  301  arranged on the second conductive wiring layer  21  and a first protective layer  302  arranged on the first adhesive layer  301 . The first cover film  30  defines third through holes  31 , the third pads  211  being exposed in the third through holes  31 . A material of the first adhesive layer  301  may be non-conductive glue. 
     At step  16 , referring to  FIG.  6   , a photosensitive ink layer  40  is formed on the first conductive wiring layer  20 . The photosensitive ink layer  40  also infills the first gaps  202 . 
     At step  17 , referring to  FIG.  7   , the photosensitive ink layer  40  is subjected to exposure to from a photosensitive midbody  41 . Specifically, part of the photosensitive ink layer  40  is polymerized and cured under the action of ultraviolet light, while the other part of the photosensitive ink layer  40  is shielded against ultraviolet light and is not polymerized (i.e. it is uncured). 
     At step  18 , referring to  FIG.  8   , the uncured portion of the photosensitive midbody  41  on the first conductive wiring layer  20  is removed, thereby forming a first patterned ink layer  42  from the photosensitive midbody  41 . Specifically, the uncured portion of the photosensitive midbody  41  on the first conductive wiring layer  20  may be removed by mechanical cutting. 
     Referring to  FIG.  8   , some of the uncured portions of the photosensitive midbody  41  are arranged in some of the first gaps  202 . That is, some of the first gaps  202  are provided with the photosensitive ink layer  40 . The first patterned ink layer  42  includes a plurality of first through holes  421 , and the first pads  201  are exposed in the first through holes  421 . 
     At step  19 , referring to  FIGS.  8  and  9   , the portion of the photosensitive ink layer  40  in the first gaps  202  is subjected to exposure and thus polymerized and cured. 
     At step  20 , referring to  FIG.  10   , a first surface treatment layer  50  is formed on the first pads  201  and a third surface treatment layer  51  is formed on the third pads  211 , thereby obtaining a first circuit substrate  52 . The first surface treatment layer  50  and the third surface treatment layer  51  each can be a layer of gold. 
     At step  21 , referring to  FIG.  11   , a second circuit substrate  60  is provided. 
     The second circuit substrate  60  includes a second base layer  601  including two opposite surfaces and a third conductive wiring layer  602  and a fourth conductive wiring layer  603  arranged on the two opposite surfaces. 
     It is to be noted, in some embodiments, the second circuit substrate  60  may be provided with conductive wiring layers (not shown) therein. A material of the second base layer  601  is the same as that of the first base layer  101 . 
     The third conductive wiring layer  602  includes a plurality of second pads  6021 , and the fourth conductive wiring layer  603  includes a plurality of fourth pads  6031 . The third conductive wiring layer  602  includes a plurality of second gaps  6025  separating the second pads  6021  from each other. The fourth conductive wiring layer  603  includes a plurality of fourth gaps  6035  separating each of the fourth pads  6031 . 
     The second circuit substrate  60  includes second heat conductive portions  61 . The third conductive wiring layer  602  can be thermally conductive with the fourth conductive wiring layer  603  through the second heat conductive portions  61 . In addition, the third conductive wiring layer  602  can also be electrically connected to the fourth conductive wiring layer  603  through the second heat conductive portions  61 . 
     The second circuit substrate  60  further includes a second patterned ink layer  62 . The second patterned ink layer  62  is arranged on the third conductive wiring layer  62 , and a portion of the second patterned ink layer  62  infills the second gaps  6025 . The second patterned ink layer  62  includes a plurality of second through holes  621 , and the second pads  6021  are exposed in the second through holes  621 . 
     The second circuit substrate  60  further includes a second cover film  63 . The second cover film  63  includes a second adhesive layer  631  arranged on the fourth conductive wiring layer  603  and a second protective layer  632  arranged on the second adhesive layer  631 . The second adhesive layer  631  can be made of non-conductive glue. 
     The second cover film  63  includes a plurality of fourth through holes  633 , and the fourth pads  6031  are exposed in the fourth through holes  633 . 
     The second circuit substrate  60  further includes a second surface treatment layer  64  and a fourth surface treatment layer  65 . The second surface treatment layer  64  is arranged on the second pads  6021 , and the fourth surface treatment layer  65  is arranged on the fourth pads  6031 . The second surface treatment layer  64  and the fourth surface treatment layer  65  each may be a layer of gold. 
     At step  22 , referring to  FIG.  12   , a first heat conductive adhesive  70  and a heat dissipation plate  71  are provided. 
     The heat dissipation plate  71  may be an aluminum plate. In some embodiments, the heat dissipation plate  71  may also be a copper plate or an iron plate. 
     At step  23 , referring to  FIG.  13   , the first circuit substrate  52  and the second circuit substrate  60  are each bonded to a surface of the heat dissipation plate  71  through the first heat conductive adhesive  70 , and the first heat conductive adhesive  70  infills a gap  72  between an end face of the first circuit substrate  52  and an end face of the second circuit substrate  60 . 
     The first heat conductive adhesive  70  further infills the third through holes  31  to be thermally conductive with the third surface treatment layer  51 , and thus to be thermally conductive with the second conductive wiring layer  21 , the first heat conductive portions  12 , and the first conductive wiring layer  20 . The first conductive wiring layer  20 , the first heat conductive portions  12 , the second conductive wiring layer  21 , the first heat conductive adhesive  70 , and the heat dissipation plate  71  together form a first heat dissipation channel. 
     The first heat conductive adhesive  70  further infills the fourth through holes  633  to be thermally conductive with the fourth surface treatment layer  65 , and so as to be thermally conductive with the fourth conductive wiring layer  603 , the second heat conductive portions  61 , and the third conductive wiring layer  602 . The third conductive wiring layer  602 , the second heat conductive portions  61 , the fourth conductive wiring layer  603 , the first heat conductive adhesive  70 , and the heat dissipation plate  71  together form a second heat dissipation channel. 
     At step  24 , referring to  FIG.  14   , the first conductive wiring layer  20  and the third conductive wiring layer  602  are each provided with a plurality of light emitting diodes  80 , at least one light emitting diode  80  is electrically connected to the first pads  201 , at least one light emitting diode  80  is electrically connected to the first pads  201  and the second pads  6021 , and at least one light emitting diode  80  is electrically connected to the second pads  6021 . 
     Each of the light emitting diodes  80  includes a main body (not shown) and a first electrode (not shown) and a second electrode (not shown) electrically connected to the main body. 
     The light emitting diodes  80  arranged on the first conductive wiring layer  20  are received in the first through holes  421 , and the light emitting diodes  80  arranged on the third conductive wiring layer  602  are received in the second through holes  621 . 
     Referring to  FIG.  14   , the first electrode and the second electrode of the light emitting diodes  80  arranged on the first conductive wiring layer  20  are electrically connected to the first surface treatment layer  50  via a plurality of conductive elements  81 . Thus each of the light emitting diodes  80  on the first conductive wiring layer  20  is electrically connected to the first pads  201 , the first conductive wiring layer  20 , and the second conductive wiring layer  21 . The first electrode and the second electrode of the light emitting diodes  80  arranged on the third conductive wiring layer  602  are electrically connected to the second surface treatment layer  64  via a plurality of conductive elements  81 . Thereby each of the light emitting diodes  80  on the third conductive wiring layer  602  is electrically connected to the second pads  6021 , the third conductive wiring layer  602 , and the fourth conductive wiring layer  603 . The first electrode and the second electrode of the light emitting diodes  80  arranged on the first conductive wiring layer  20  and the third conductive wiring layer  602  are respectively electrically connected to the first surface treatment layer  50  and the second surface treatment layer  64  via a plurality of conductive elements  81 , thus electrically connected to the first pad  201  and the second pad  6021 , and thereby being electrically connected to the first conductive wiring layer  20 , the second conductive wiring layer  21 , the third conductive wiring layer  602 , and the fourth conductive wiring layer  603 . That is, at least one of the light emitting diodes  80  is located on the first conductive wiring layer  20  and the third conductive wiring layer  602 . 
     In some embodiments, the conductive elements  81  may be conductive paste. Specifically, the conductive paste can be solder paste, copper paste, etc. The conductive members  81  have a high thermal conductivity. 
     At step  25 , referring to  FIGS.  14  and  15   , the first through holes  421  and the second through holes  621  are filled with second heat conductive adhesive  90 , thereby obtaining the display module  100 . 
     A surface of each of the light emitting diodes  80  away from the heat dissipation plate  71  is lower than or flush with a surface of the first patterned ink layer  42  or the second patterned ink layer  62  away from the heat dissipation plate  71 , so as to improve the flatness of the display module  100 . 
     The heat generated by the light emitting diodes  80  located on the first conductive wiring layer  20  is transmitted to the first heat dissipation channel through the conductive members  81  and the second heat conductive adhesive  90 , and to an external environment through the first heat dissipation channel. The heat generated by the light emitting diodes  80  located on the third conductive wiring layer  602  is transmitted to the second heat dissipation channel through the conductive members  81  and the second heat conductive adhesive  90 , and to the external environment through the second heat dissipation channel. At the same time, the heat generated by the light emitting diodes  80  located on the first conductive wiring layer  20  and the third conductive wiring layer  602  is transmitted to the first heat dissipation channel and the second heat dissipation channel through the conductive members  81  and the second heat conductive adhesive  90 , and to the external environment through the first heat dissipation channel and the second heat dissipation channel. 
     Referring to  FIGS.  13  to  15   , the second heat conductive adhesive  90  further infills the gap  72  and makes contact with the first heat conductive adhesive  70 . Heat generated by the light emitting diodes  80  located on the first conductive wiring layer  20  and the third conductive wiring layer  602  is transmitted to the external environment through the second heat conductive adhesive  90 , the first heat conductive adhesive  70 , and the heat dissipation plate  71 . 
     Referring to  FIG.  15   , an embodiment of the present disclosure provides the display module  100  which includes a first circuit substrate  52 , a second circuit substrate  60 , a heat dissipation plate  71 , a first heat conductive adhesive  70 , a plurality of light emitting diodes  80 , and a second heat conductive adhesive  90 . 
     The first circuit substrate  52  includes a first base layer  101  having two opposite surfaces and a first copper foil layer  102  and a second copper foil layer  103  formed on the surfaces. 
     The first base layer  101  is made of a resin which may be selected from a group consisting of epoxy resin, polypropylene, polyphenylene oxide, polyimide, polyethylene terephthalate, polyethylene naphthalate, and any combination thereof. In one embodiment, the first base layer  101  is made of polyimide. 
     It is to be noted, in some embodiments, the first base layer  101  may be provided with a plurality of conductive wiring layers (not shown) therein. 
     The first conductive wiring layer  20  includes a plurality of first pads  201 , and the second conductive wiring layer  21  includes a plurality of third pads  211 . A plurality of first gaps  202  are formed in the first conductive wiring layer  20 , and adjacent first pads  201  are separated from each other by one first gap  202 . A plurality of third gaps  212  are formed in the second conductive wiring layer  21 , and adjacent third pads  211  are separated from each other by one third gap  212 . 
     The first circuit substrate  52  further includes a plurality of first heat conductive portions  12 . The first conductive wiring layer  20  is thermally conductive with the second conductive wiring layer  21  through the first heat conductive portions  12 . In addition, the first conductive wiring layer  20  can also be electrically connected to the second conductive wiring layer  21  through the first heat conductive portions  12 . 
     The first circuit substrate  52  further includes a first cover film  30 . The first cover film  30  includes a first adhesive layer  301  arranged on the second conductive wiring layer  21  and a first protective layer  302  arranged on the first adhesive layer  301 . The first cover film  30  defines a plurality of third through holes  31 , and the third pads  211  are exposed in the third through holes  31 . A material of the first adhesive layer  301  may be pure glue. 
     The first circuit substrate  52  further includes a first patterned ink layer  42 . The first patterned ink layer  42  is arranged on the first conductive wiring layer  20 , where a portion of the first patterned ink layer  42  infills some of the first gaps  202 . The first patterned ink layer  42  includes a plurality of first through holes  421 , and the first pads  201  are exposed in the first through holes  421 . 
     The first circuit substrate  52  further includes a first surface treatment layer  50  and a third surface treatment layer  51 . The first surface treatment layer  50  is arranged on the first pads  201 , and the third surface treatment layer  51  is arranged on the third pads  211 . In one embodiment, the first surface treatment layer  50  and the third surface treatment layer  51  each can be a gold layer. 
     The second circuit substrate  60  includes a second base layer  601  including two opposite surfaces and a third conductive wiring layer  602  and a fourth conductive wiring layer  603  arranged on the surfaces. 
     It is to be noted, in some embodiments, the second circuit substrate  60  may be provided with a plurality of conductive wiring layers (not shown) therein. A material of the second base layer  601  may be the same as that of the first base layer  101 . 
     The third conductive wiring layer  602  includes a plurality of second pads  6021 , and the fourth conductive wiring layer  603  includes a plurality of fourth pads  6031 . The third conductive wiring layer  602  includes a plurality of second gaps  6025  separating the second pads  6021  from each other. The fourth conductive wiring layer  603  includes a plurality of fourth gaps  6035  separating the fourth pads  6031  from each other. 
     The second circuit substrate  60  includes a plurality of second heat conductive portions  61 . The third conductive wiring layer  602  is thermally conductive with the fourth conductive wiring layer  603  through the second heat conductive portions  61 . In addition, the third conductive wiring layer  602  can also be electrically connected to the fourth conductive wiring layer  603  the second heat conductive portions  61 . 
     The second circuit substrate  60  further includes a second patterned ink layer  62 . The second patterned ink layer  62  is arranged on the third conductive wiring layer  62 , and a portion of the second patterned ink layer  62  infills the second gaps  6025 . The second patterned ink layer  62  includes a plurality of second through holes  621 , and the second pads  6021  are exposed in the second through holes  621 . 
     The second circuit substrate  60  further includes a second cover film  63 . The second cover film  63  includes a second adhesive layer  631  arranged on the fourth conductive wiring layer  603  and a second protective layer  632  arranged on the second adhesive layer  631 . The second adhesive layer  631  can be made of non-conductive glue. 
     The second cover film  63  includes a plurality of fourth through holes  633 , and the fourth pads  6031  are exposed in the fourth through holes  633 . 
     The second circuit substrate  60  further includes a second surface treatment layer  64  and a fourth surface treatment layer  65 . The second surface treatment layer  64  is arranged on the second pads  6021 , and the fourth surface treatment layer  65  is arranged on the fourth pads  6031 . The second surface treatment layer  64  and the fourth surface treatment layer  65  each may be a gold layer. 
     The first circuit substrate  52  and the second circuit substrate  52  are each arranged on the heat dissipation plate  71 . The heat dissipation plate  71  may be an aluminum plate. In some embodiments, the heat dissipation plate  71  may also be a copper plate or an iron plate. 
     The first heat conductive adhesive  70  is arranged between the first circuit substrate  52  and the heat dissipation plate  71  and between the second circuit substrate  60  and the heat dissipation plate  71 . The first heat conductive adhesive  70  further infills a gap  72  between an end face of the first circuit substrate  52  and an end face of the second circuit substrate  60 . 
     The first heat conductive adhesive  70  further infills the third through holes  31  to be thermally conductive with the third surface treatment layer  51 , and thus to be thermally conductive with the second conductive wiring layer  21 , the first heat conductive portions  12 , and the first conductive wiring layer  20 . The first conductive wiring layer  20 , the first heat conductive portions  12 , the second conductive wiring layer  21 , the first heat conductive adhesive  70 , and the heat dissipation plate  71  together form a first heat dissipation channel. 
     The first heat conductive adhesive  70  further infills the fourth through holes  633  to be thermally conductive with the fourth surface treatment layer  65 , and so as to be thermally conductive with the fourth conductive wiring layer  603 , the second heat conductive portions  61 , and the third conductive wiring layer  602 . The third conductive wiring layer  602 , the second heat conductive portions  61 , the fourth conductive wiring layer  603 , the first heat conductive adhesive  70 , and the heat dissipation plate  71  together form a second heat dissipation channel. 
     The first conductive wiring layer  20  and the third conductive wiring layer  602  are each provided with a plurality of light emitting diodes  80 , at least one light emitting diode  80  is electrically connected to the first pads  201 , at least one light emitting diode  80  is electrically connected to the first pads  201  and the second pads  6021 , and at least one light emitting diode  80  is electrically connected to the second pads  6021 . 
     Each of the light emitting diodes  80  includes a main body (not shown) and a first electrode (not shown) and a second electrode (not shown) electrically connected to the main body. 
     The light emitting diodes  80  arranged on the first conductive wiring layer  20  are received in the first through holes  421 , and the light emitting diodes  80  arranged on the third conductive wiring layer  602  are received in the second through holes  621 . 
     The first electrode and the second electrode of the light emitting diode  80  arranged on the first conductive wiring layer  20  are electrically connected to the first surface treatment layer  50  via conducting elements  81 . Thus the light emitting diode  80  on the first conductive wiring layer  20  is electrically connected to the first pads  201 , the first conductive wiring layer  20 , and the second conductive wiring layer  21 . The first electrode and the second electrode of the light emitting diode  80  arranged on the third conductive wiring layer  602  are electrically connected to the second surface treatment layer  64  via the conductive elements  81 . Thus the light emitting diode  80  on the third conductive wiring layer  602  is electrically connected to the second pads  6021 , the third conductive wiring layer  602 , and the fourth conductive wiring layer  603 . The first electrode and the second electrode of the light emitting diode  80  arranged on the first conductive wiring layer  20  and the third conductive wiring layer  602  are respectively electrically connected to the first surface treatment layer  50  and the second surface treatment layer  64  via the conductive elements  81 , thus to be respectively electrically connected to the first pad  201  and the second pad  6021 , thereby being electrically connected to the first conductive wiring layer  20 , the second conductive wiring layer  21 , the third conductive wiring layer  602 , and the fourth conductive wiring layer  603 . That is, at least one of the light emitting diodes  80  is located on the first conductive wiring layer  20  and the third conductive wiring layer  602 . 
     The second heat conductive adhesive  90  infills the first through holes  421  and the second through holes  621 . A surface of each of the light emitting diodes  80  away from the heat dissipation plate  71  is lower than or flush with a surface of the first patterned ink layer  42  or the second patterned ink layer  62  away from the heat dissipation plate  71 , so as to improve the flatness of the display module  100 . 
     The heat generated by the light emitting diodes  80  located on the first conductive wiring layer  20  is transmitted to the first heat dissipation channel through the conductive members  81  and the second heat conductive adhesive  90 , and to an external environment through the first heat dissipation channel. The heat generated by the light emitting diodes  80  located on the third conductive wiring layer  602  is transmitted to the second heat dissipation channel through the conductive members  81  and the second heat conductive adhesive  90 , and to the external environment through the second heat dissipation channel. At the same time, the heat generated by the light emitting diodes  80  located on the first conductive wiring layer  20  and the third conductive wiring layer  602  is transmitted to the first heat dissipation channel and the second heat dissipation channel through the conductive members  81  and the second heat conductive adhesive  90 , and to the external environment through the first heat dissipation channel and the second heat dissipation channel. 
     The second heat conductive adhesive  90  further infills the gap  72  to make contact with the first heat conductive adhesive  70 . Heat generated by the light emitting diodes  80  located on the first conductive wiring layer  20  and the third conductive wiring layer  602  can be transmitted to the external environment through the second heat conductive adhesive  90 , the first heat conductive adhesive  70 , and the heat dissipation plate  71 . 
     After the first circuit substrate  52  and the second circuit substrate  60  are adhered to the heat dissipation plate  71  by the first heat conductive adhesive  70 , the light emitting diodes  80  are respectively mounted onto the first conductive wiring layer  20  and the third conductive wiring layer  602 , so that the flatness of the light emitting diodes  80  is improved, the probability of inclination of the light emitting diodes  80  is decreased, the uniformity of light emission of the light emitting diodes  80  is improved, and uniformity of brightness and color of the display module  100  is improved. In addition, at least one of the light emitting diodes  80  is disposed on a boundary between the first circuit substrate  52  and the second circuit substrate  60 , so that a black line present at the boundary is reduced or canceled, and the display quality of the display module  100  is improved. 
     In addition, the heat generated by the light emitting diodes  80  can be transmitted to the first heat dissipation channel or the second heat dissipation channel through the conductive members  81  and the second heat conductive adhesive  90 , and to the external environment through the first heat dissipation channel or the second heat dissipation channel, so that the heat dissipation performance of the display module  100  is improved. The adjacent light-emitting diodes  80  are separated by the first patterned ink layer  42  or by the second patterned ink layer  62 , such that heat generated by the two adjacent light emitting diodes  80  dissipate heat separately and independently, without mutual influence, so that heat is not accumulated. 
     In addition, the first through holes  421  and the second through holes  621  are infilled with the second heat conductive adhesive  90  separately, the stability of the light emitting diodes  80  is improved, thereby improving the reliability of the display module  100 . 
     While the present disclosure has been described with reference to particular embodiments, the description is illustrative of the disclosure and is not to be construed as limiting the disclosure. Therefore, those of ordinary skill in the art can make various modifications to the embodiments without departing from the scope of the disclosure as defined by the appended claims.