200528837 玖、發明說明： 【發明所屬之技術領域】 本發明係提供一種背光模組，尤指一種可遏止電磁干擾現 象之背光模組。 【先前技術】 近年來，各種顯示技術不斷的蓬勃發展，經過持續的研究 開發之後，如液晶顯示器、電漿顯示器、有機發光二極體顯示 器等新產品，已逐漸的商業化並應用於各種尺寸以及各種面積 的顯不裝置。目前整個顯不裔業界’無不朝向ifj党度以及效 率化發展，以期能製作出更具商業價值的顯示器產品。而在顯 示器的各種關鍵零組件當中，用來供應光源的背光模組，對顯 示器整體的發光效率有舉足輕重的影響力，當背光模組本身具 有優良的發光效率時，不僅可以提昇顯示器的亮度，也提供了 顯示器中其他組件設計以及製造上的彈性，但是當背光模組本 身的發光效率不佳時，所能提供的光源有限，往往限制了顯示 器產品的亮度表現。 背光模組的結構一般分為側光式及直下式二種，且二者應 用的範圍有所不同。側光式只採用一支冷陰極管，置於模組的 側邊，再利用楔型構造使光源均勻反射至整片模組，這樣的結 構因為可以減少模組的厚度，適合於筆記型電腦這類可攜式產 品，不過在亮度的均一性就較難控制；直下型結構則是將燈管 全面置於模組，且燈管數在二支以上，因而可獲得較大的亮 度，不過耗電量會隨著燈管數增加而相對提高，模組的厚度也 會跟著加大不少，因此直下型適合運用於LCD監視器及液晶電 視用的面板模組。 200528837 請參考圖-至圖三，圖-至圖三為 模組ίο之結構示意圖。如圖—所示，羽土 了中直下式月先 10係包含有-金屬背板12,且全屬背：°二直下式背光模組 、 孟屬月板12的正面14之上邛 置有複數個提供光源的燈管（未顯示）。 ° 對之-第-邊緣16以及—第二邊緣)18^二板12具有兩相 面24分別設置於第-邊、緣16以及第緣、=22以及一斜 燈管（未顯示）發射出來的光線反射，再·;光線進;= M(未顯不）’取後產生均勻的面性光源。由於 ^至中之其他零件，因此，金屬背板丨2中 —延伸板28分別連接至斜面22以 及斜面2 4，以便於爾後做域時，可以藉由延伸板2 6、2 之各種没計將金屬背板12輕易連接至其他的零件。 如果從金屬背板12的背面32觀察，可以很清楚的 斜面22、24以及延伸板26、28分別構成了凹槽結構34、36， 且凹槽結構34、36係分別與第一邊緣16以及第二邊緣㈣目 連。金屬背板12上另包含有複數個突起物38以及螺絲孔^， 突起物38係用來架高印刷電路板（未顯示），以防止其盘金 背板12短路；而部份之螺絲孔42係先對金屬背板12'做開孔 44，再製作而成，以用來鎖附印刷電路板（未顯示）。 如圖^所示，直下式背光模組丨〇另包含有一控制板46，控 制板46係為一印刷電路板，並與軟性印刷電路板48相連。控 制板46係設置於突起物38之上以防止前述之短路現象，其= 要是靠被鎖附至螺絲孔42而固定（請一併參考圖_)，並^由 軟性印刷電路板48與掌管控制的電路訊號板（未顯示）相連， 以傳達各種訊號。軟性印刷電路板48係繞折至延伸板託的側 面，再外罩殼體50。如圖三所示，一用來防止電磁干擾之封 200528837 蓋52設置於金屬背板19 印刷電路板48(請—併失=，f覆蓋住控制板46以及軟性 封蓋52被鎖附至全屬1;考=二），以防止電磁干擾的現象。 千佯至屬月板12，内含控制板46,以防止電磁波 干擾，亚保護控制板46。 12 td支：之直下式背光模組10中’係完全利用金屬背板 折曼征㈣以鎖附控制板46，並使軟性印刷電路板48反 ^至延伸板26之側面，外軍殼體50之後，再蓋上封蓋52。 在這樣的結構中，雖妷Ρ妹料干』τ 丹盖上釘盍5Ζ θ χ . …、已、、二對電磁干擾現象做了若干防護，但 二面：2开因為’斜面22以及延伸板26於金屬背板12 ::=12 了如前所述之凹槽結構34，所以即使封蓋52 48二/板12之上用來遮蔽控制板46以及軟性印刷電 經由軟性印刷電路板48不斷在控制板46與 ΓΛϋ 之㈣輸時，電磁波健會從凹槽結構 34中散出（如圖三之箭頭所、 a 炙幻頭所不），達不到全面防護的功效。尤 :疋备控制板46與軟性印刷電路板48表面電路非常複雜，走 J很多」操作頻率高時，問題更容易被突顯出來。針對這樣的 月开少I又的解决方法疋視需要塗佈具有防護電磁干擾作用的 銀膠，但所收到的效果仍然有限。 此外S知技術之直下式背光模、组10巾，係先對金屬背板 12做破壞性的開孔44,再製作螺絲孔仏，以鎖附控制板祁， 每種方法無庸置疑地會降低結構體的機械強度。而在一些習知 技術中，也採用將控制板46直接鎖附在金屬背板12上的方 法，但仍然會降低結構體的機械強度。因此，如何發展出一種 新的直下式背光模組結構’其不僅能有效遏止電磁;擾現象， 結構體又能具有理想的機械強度，便成為十分重要的課題。 【發明内容】 10 200528837 因此本發明之目的係提供一種背光模組，以解決上述問 題0 在本發明之較佳實施例中，係提供一種背光模組，該背光 模組包含有一反射背板，該反射背板之至少一邊緣設置有一反 射斜面以及一延伸板，且該反射斜面以及該延伸板構成一凹槽 結構，一橋接物橫跨於部份之該凹槽結構之上，至少一電路板 設置於該橋接物以及該反射背板之上，以及一蓋板設置於該橋 接物以及該反射背板之上並覆蓋該電路板，且該蓋板與該橋接 物以及該反射背板構成一密閉空間。 由於本發明之背光模組係利用一橋接物在背板的凹槽結構 之上架橋，以覆蓋部份之凹槽結構，並利用橋接物上之螺絲孔 來固定控制板，因此於封蓋蓋上之後，封蓋、背板以及橋接物 將形成密閉的空間以容置控制板以及軟性印刷電路板，並防止 電磁波溢出以達到防護電磁干擾現象的目的。此外，本發明之 背光模組不僅僅利用背板來作為支撐，亦利用橋接物來提供額 外的實體結構，不但可以加強整個結構體的機械強度，亦可以 在橋接物之上製作螺絲孔，以利用螺絲將控制板固定於橋接物 之上，避免了對背板做破壞性的開孔以鎖附控制板的需要，所 以不至於影響結構體的機械強度。 【實施方式】 請參考圖四至圖七，圖四至圖七為本發明中直下式背光模 組100之結構示意圖。如圖四所示，本發明之直下式背光模組 100係包含有一背板102，背板102的正面104之上設置有複 數個提供光源的燈管（未顯示），且燈管（未顯示）係為一直管或 是一 U管。背板102具有兩相對之一第一邊緣106以及一第二 11 200528837 邊緣108, 一斜面112以及一斜面114分別設置於第一邊緣1〇6 以及第二邊緣108，以將部份自燈管（未顯示）發射出來的光線 反射，再使光線進入上方的光學膜（未顯示），最後產生更大更 均勻的面性光源。由於背板102尚需被組裝至顯示器產品中之 其他令件，因此，月板1〇2中另設置有一延伸板ία以及一延 伸板118分別連接至斜面112以及斜面Π4，以便於爾後做組 裝時，可以藉由延伸板Π6、118上之各種設計將背板1〇2輕 易連接至其他的零件。另外，背板1〇2係包含有一鋁板、一鋁 合金板或是一其他導電金屬板。 如果從背板102的背面122觀察，可以很清楚的看到，斜 面112、114以及延伸板116、118分別構成了凹槽結構124、 126 ’且凹槽結構124、126係分別與第一邊緣1〇6以及第二邊 緣108相連。事實上，背才反1〇2可能為一一體成型的結構，或 為-經過焊接而成的結構。背板1G2之上另包含有複數個突起 物128用來杀鬲印刷電路板（未顯示），以防止其與背板1⑽ 如圖五所示，直下式背光模組1〇〇包含有一橋接物132， 份之凹槽結構124之上，並且透過螺絲134被固定於 月板102之上。如圖六所示，直下式背光模組1〇〇另包含有一 :广板136係為一印刷電路板，並與軟性印刷電 控制板136係設置於突起物128之上以防止前 述之短路現象，其主要係透過螺絲（ =未之ΐ-ΐ?軟性印刷電路板138與掌管控 板（未顯不）相連’以傳達各種訊號。值得-提的是，軟性印刷 ί 由至少—連接11 (未顯示）與控制板136以及電 相連’而連接的方法係包含有—般的烊接連 面黏著。軟性印刷電路板138係繞折至延伸板116 12 200528837 的側面，再外罩殼體140。 如圖七所示，一用來防止電磁干擾之封蓋144設置於背板 以及橋接物132之上，並覆蓋住控制板136以及軟性印刷 笔路板138 (請一併參考圖六）。封蓋144視實際的需要，可 以被鎖附至背板102、橋接物132或是控制板136，於圖七中 係利用螺絲146被鎖附至控制板136。此時，封蓋144與橋接 物132以及背板1〇2係構成一密閉空間，以容置控制板136以 及軟性印刷電路板138，因此，封蓋144下方之凹槽結構124， 不再成為電磁干擾防制上的死角，對於電磁干擾現象的防護， 有莫大的功效。 言之，在本發明之直下式背光模組1〇〇中，並非完全利 用背板102來作為支撐，而是利用橋接物132在凹槽結構124 =上架橋（此位置係位於部份之軟性印刷電路板的下方），使橋 覆蓋住部份之凹槽結構124，於封蓋144蓋上之後，ς 象岔閉的空間，以防止電磁波溢出，進而達到防護電磁干擾現 的目的。而在另一方面，橋接物132提供了額外的實^結 ，其不僅加強了整個結構體的機械強度，亦可以在其上= 全、絲孔，以利用螺絲鎖附並且固定控制板136，完全避^羽 技術中需先對金屬背板12做破壞性的開孔44，再製 白 开二鎖附控制板46，以致於降低結構體的機械強度的:口 〜请參考圖-與圖二）。因此，本發 广障 結構主體上開孔以增加結構體機械強付合减少在 值知·一提的是，本發明之背先槎細，廿艾你阳认丄 中之結構，凡利用一橋接物來與封蓋以及背板構成—以 路板，均涵蓋在本發明㈣圍之内。^ ί &月中橋接物與背板可為一體之結構。 本 13 200528837 由於本發明之背光模組，係利用一橋接物在背板的凹槽結 構之上架橋，以覆蓋部份之凹槽結構，並利用橋接物上之螺絲 孔來固定控制板，因此於封蓋蓋上之後，封蓋、背板以及橋接 物將形成密閉的空間以容置控制板以及軟性印刷電路板，進而 防止電磁波溢出。如此一來，不僅可以達到防護電磁干擾現象 的目的，又可以加強結構體的強度。利用本發明之結構於一實 際生產線時，將可以生產出具有優良電磁干擾遮蔽性以及優良 機械強度之背光模組。 相較於習知技術，本發明之背光模組係利用一橋接物在背 板的凹槽結構之上架橋，以覆蓋部份之凹槽結構，並利用橋接 物上之螺絲孔來固定控制板，因此於封蓋蓋上之後，封蓋、背 板以及橋接物將形成密閉的空間以容置控制板以及軟性印刷 電路板，並防止電磁波溢出以達到防護電磁干擾現象的目的。 同時，本發明之背光模組不僅僅利用背板來作為支撐，亦利用 橋接物來提供額外的實體結構，不但可以加強整個結構體的機 械強度，亦可以在橋接物之上製作螺絲孔，以利用螺絲將控制 板固定於橋接物之上，完全避免了對背板做破壞性的開孔以鎖 附控制板的需要，所以不至於影響結構體的機械強度。 以上所述僅為本發明之較佳實施例，凡依本發明申請專利 範圍所做之均等變化與修飾，皆屬本發明專利之涵蓋範圍。 【圖式簡單說明】 圖式之簡單說明 圖一至圖三為習知技術中直下式背光模組之結構示意圖。 圖四至圖七為本發明中直下式背光模組之結構示意圖。 14 200528837 圖式之符號說明 10 、 100 直下式背光模組 12 金屬背板 14 、 104 正面 16 、 106 第一邊緣 18 、 108 第二邊緣 22 、 24 、 112 、 114 斜面 26 、 28 、 116 、 118 延伸板 32 、 122 背面 34 、 36 、 124 、 126 凹槽結構 38 、 128 突起物 42 螺絲iL 44 開孔 46 、 136 控制板 48 、 138 軟性印刷電路板 50 、 140 殼體 52 、 144 封蓋 102 背板 132 橋接物 134 、 146 螺絲 15200528837 发明 Description of the invention: [Technical field to which the invention belongs] The present invention provides a backlight module, especially a backlight module capable of suppressing electromagnetic interference. [Previous technology] In recent years, various display technologies have continued to flourish. After continuous research and development, new products such as liquid crystal displays, plasma displays, and organic light emitting diode displays have gradually been commercialized and applied to various sizes. And display devices of various areas. At present, the entire display industry is all developing towards ifj and party efficiency and efficiency, with a view to producing more commercial display products. Among the various key components of the display, the backlight module used to supply the light source has a significant influence on the overall luminous efficiency of the display. When the backlight module itself has excellent luminous efficiency, it can not only improve the brightness of the display, It also provides flexibility in the design and manufacturing of other components in the display. However, when the light-emitting efficiency of the backlight module itself is not good, the available light sources are limited, which often limits the brightness performance of the display products. The structure of the backlight module is generally divided into two types: the edge light type and the direct type, and the application scope of the two is different. The edge-light type uses only one cold cathode tube, placed on the side of the module, and then uses a wedge-shaped structure to uniformly reflect the light source to the entire module. This structure is suitable for notebook computers because it can reduce the thickness of the module This type of portable products, however, is more difficult to control in terms of uniformity of brightness; in the direct-type structure, the lamp is fully placed in the module, and the number of lamps is more than two, so it can obtain greater brightness, but The power consumption will increase relatively with the increase of the number of lamps, and the thickness of the module will also increase a lot. Therefore, the direct type is suitable for panel modules for LCD monitors and LCD TVs. 200528837 Please refer to Figure-to Figure 3, Figure-to Figure 3 are the schematic diagram of the module ίο. As shown in the figure, the top-down type of the first 10 series of the middle straight type includes a metal back plate 12, and all belong to the back: ° Two direct-type backlight modules, and the front 14 of the Monsoon moon plate 12 are placed on it. A plurality of lamps (not shown) that provide a light source. ° Opposite-the first edge 16 and the second edge) 18 ^ The second plate 12 has two phase surfaces 24 disposed at the first edge, the edge 16 and the second edge, = 22, and an oblique light tube (not shown) emitted. The light is reflected, and then the light enters; = M (not shown) 'to produce a uniform surface light source. Due to other parts, the metal back plate 2-the extension plate 28 is connected to the inclined surface 22 and the inclined surface 2 4 respectively, so that when the field is made later, the various types of extension plates 2 6 and 2 can be used. The metal back plate 12 is easily connected to other parts. If viewed from the back surface 32 of the metal back plate 12, it can be clearly seen that the inclined surfaces 22, 24 and the extension plates 26, 28 respectively constitute the groove structures 34, 36, and the groove structures 34, 36 are respectively connected to the first edge 16 and The second edge is eye-catching. The metal back plate 12 further includes a plurality of protrusions 38 and screw holes ^. The protrusions 38 are used to elevate the printed circuit board (not shown) to prevent the gold back plate 12 from being short-circuited; and part of the screw holes The 42 series is made by making an opening 44 into the metal back plate 12 ', and then used to lock a printed circuit board (not shown). As shown in Fig. ^, The direct type backlight module includes a control board 46. The control board 46 is a printed circuit board and is connected to the flexible printed circuit board 48. The control board 46 is arranged on the protrusion 38 to prevent the aforementioned short-circuit phenomenon. It = if it is fixed by being locked to the screw hole 42 (please refer to the figure _), and is controlled by the flexible printed circuit board 48 and the control The control circuit signal board (not shown) is connected to convey various signals. The flexible printed circuit board 48 is folded to the side of the extension plate holder, and then covers the casing 50. As shown in Figure 3, a seal 200528837 is used to prevent electromagnetic interference. The cover 52 is provided on the metal back plate 19 and the printed circuit board 48 (please—and lose =, f covers the control board 46 and the soft cover 52 is locked to the whole). Gen. 1; test = 2) to prevent the phenomenon of electromagnetic interference. Qianxizhi belongs to the moon board 12, which includes a control board 46 to prevent electromagnetic wave interference, and sub-protect the control board 46. 12 td support: In the direct type backlight module 10, the metal back plate is used to fold the battery to lock the control board 46, and the flexible printed circuit board 48 is reversed to the side of the extension board 26. The outer casing After 50, the cover 52 is closed again. In such a structure, although 妷 Ρ 妹 料 干 ”τ Dan cover nails 5Z θ χ.…, Have, and two have made some protection against electromagnetic interference phenomena, but the two sides: 2 open because of the 'slope 22 and extension The plate 26 has the groove structure 34 as described above on the metal back plate 12 :: = 12, so even if the cover 52 48 / board 12 is used to shield the control board 46 and the flexible printed circuit board via the flexible printed circuit board 48 When the control board 46 and ΓΛϋ continue to be lost, the electromagnetic wave will be scattered from the groove structure 34 (as shown by the arrow in Figure 3 and not by the scorching head), which will not achieve the full protection effect. Especially: The surface circuits of the preparation control board 46 and the flexible printed circuit board 48 are very complicated. If the operating frequency is high, the problem is more likely to be highlighted. In order to solve this problem, I need to apply silver glue with protection against electromagnetic interference, but the effect is still limited. In addition, the direct-type backlight mold of the known technology, a group of 10 towels, is firstly made a destructive opening 44 in the metal back plate 12, and then made a screw hole 仏 to lock the control board. Each method will undoubtedly reduce Mechanical strength of the structure. In some conventional technologies, a method of directly locking the control plate 46 to the metal back plate 12 is also adopted, but the mechanical strength of the structure is still reduced. Therefore, how to develop a new direct-type backlight module structure ', which can not only effectively suppress electromagnetic interference, but also the structure with ideal mechanical strength, has become a very important issue. [Summary of the Invention] 10 200528837 Therefore, the object of the present invention is to provide a backlight module to solve the above problems. In a preferred embodiment of the present invention, a backlight module is provided. The backlight module includes a reflective back plate. At least one edge of the reflective back plate is provided with a reflective bevel and an extension plate, and the reflective bevel and the extension plate form a groove structure, a bridge spans a part of the groove structure, and at least one circuit A plate is disposed on the bridge and the reflective back plate, and a cover plate is disposed on the bridge and the reflective back plate and covers the circuit board, and the cover plate is formed with the bridge and the reflective back plate. An enclosed space. Since the backlight module of the present invention uses a bridge to bridge over the groove structure of the back plate to cover a part of the groove structure, and uses the screw holes on the bridge to fix the control board, the cover is covered with a cover. After being mounted, the cover, the back plate and the bridge will form a closed space to house the control board and the flexible printed circuit board, and prevent the electromagnetic wave from overflowing to achieve the purpose of protecting the electromagnetic interference phenomenon. In addition, the backlight module of the present invention not only uses a back plate as a support, but also uses a bridge to provide an additional physical structure, which can not only enhance the mechanical strength of the entire structure, but also make screw holes on the bridge to The control board is fixed on the bridge with screws, which avoids the need to make a destructive opening to the back board to lock the control board, so it will not affect the mechanical strength of the structure. [Embodiment] Please refer to FIGS. 4 to 7, which are schematic structural diagrams of a direct type backlight module 100 according to the present invention. As shown in FIG. 4, the direct type backlight module 100 of the present invention includes a back plate 102, and a plurality of lamps (not shown) for providing light sources are disposed on the front surface 104 of the back plate 102, and the lamps (not shown) ) Is a straight tube or a U tube. The back plate 102 has two opposite first edges 106 and a second 11 200528837 edge 108, an inclined surface 112 and an inclined surface 114 are respectively disposed on the first edge 106 and the second edge 108, so as to partially part the tube from the lamp. (Not shown) the emitted light is reflected, and then the light enters the upper optical film (not shown), and finally produces a larger and more uniform surface light source. Since the back plate 102 needs to be assembled into other display components in the display product, an extension plate ία and an extension plate 118 are also provided in the meniscus 102 to connect to the bevel 112 and the bevel Π4, respectively, so as to facilitate assembly later. At this time, the back plate 102 can be easily connected to other parts by various designs on the extension plates Π6, 118. In addition, the back plate 102 includes an aluminum plate, an aluminum alloy plate, or another conductive metal plate. If viewed from the back 122 of the back plate 102, it can be clearly seen that the inclined surfaces 112, 114 and the extension plates 116, 118 respectively constitute the groove structures 124 and 126 ', and the groove structures 124 and 126 are respectively connected to the first edge. 106 and the second edge 108 are connected. In fact, the back can be a one-piece structure, or a welded structure. The back plate 1G2 further includes a plurality of protrusions 128 for killing the printed circuit board (not shown) to prevent it from contacting the back plate 1. As shown in FIG. 5, the direct type backlight module 100 includes a bridge. 132, the top groove structure 124 is fixed on the meniscus 102 through screws 134. As shown in FIG. 6, the direct type backlight module 100 further includes: a wide board 136 is a printed circuit board, and a flexible printed electrical control board 136 is disposed on the protrusion 128 to prevent the aforementioned short circuit phenomenon. , Which is mainly connected by screws (= 未 之 ΐ-ΐ? Flexible printed circuit board 138 and the control board (not shown) 'to convey various signals. It is worth mentioning that the flexible printing is made from at least-connection 11 ( (Not shown) The method of connection with the control board 136 and electrical connection includes the general connection surface adhesion. The flexible printed circuit board 138 is folded to the side of the extension board 116 12 200528837, and then covers the housing 140. As shown in FIG. 7, a cover 144 for preventing electromagnetic interference is disposed on the back plate and the bridge 132, and covers the control board 136 and the flexible printed circuit board 138 (please refer to FIG. 6 together). 144 may be locked to the back plate 102, the bridge 132, or the control board 136 according to actual needs. In FIG. 7, the screws 146 are used to lock the control board 136. At this time, the cover 144 and the bridge 132 are locked. And the back panel 102 constitutes a closed space, The control board 136 and the flexible printed circuit board 138 are accommodated. Therefore, the groove structure 124 under the cover 144 is no longer a dead angle in the prevention of electromagnetic interference, and has a great effect on the protection of electromagnetic interference phenomena. In the direct-type backlight module 100 of the present invention, the back plate 102 is not used completely as a support, but a bridge 132 is used in the groove structure 124 = a bridge (this position is located in a part of the flexible printed circuit) Under the board), so that the bridge covers part of the groove structure 124. After being covered by the cover 144, the space is closed like a switch to prevent electromagnetic waves from overflowing, and thus to achieve the purpose of protecting electromagnetic interference. On the one hand, the bridge 132 provides an additional solid structure, which not only strengthens the mechanical strength of the entire structure, but also can be full and silk holes on it to lock and fix the control board 136 with screws, completely avoiding feathers. In the technology, it is necessary to make a destructive opening 44 in the metal back plate 12, and then make a control panel 46 with a white opening to lock the control plate 46, so as to reduce the mechanical strength of the structure: please refer to Figure-and Figure 2). Therefore, openings in the main body of the barrier structure of the present invention are used to increase the mechanical strength of the structure and reduce the reduction. It is worth mentioning that the back of the present invention is detailed first. The bridge is composed of the cover and the backboard—the road board is included in the scope of the present invention. ^ & Mid-month bridges and backplanes can be integrated. 13 200528837 Because the backlight module of the present invention uses a bridge to bridge over the groove structure of the backplane to cover part of the groove structure, and the screw holes on the bridge are used to fix the control board, so After the cover is closed, the cover, the back plate and the bridge will form a closed space to house the control board and the flexible printed circuit board, thereby preventing electromagnetic waves from overflowing. In this way, not only the purpose of preventing electromagnetic interference can be achieved, but also the strength of the structure can be enhanced. When the structure of the present invention is used in an actual production line, a backlight module having excellent electromagnetic interference shielding properties and excellent mechanical strength can be produced. Compared with the conventional technology, the backlight module of the present invention uses a bridge to bridge the groove structure of the back plate to cover a part of the groove structure, and uses a screw hole on the bridge to fix the control board. Therefore, after the cover is closed, the cover, the back plate and the bridge will form a closed space to accommodate the control board and the flexible printed circuit board, and prevent the electromagnetic wave from overflowing to achieve the purpose of protecting the electromagnetic interference phenomenon. At the same time, the backlight module of the present invention not only uses the back plate as a support, but also uses a bridge to provide an additional physical structure, which can not only enhance the mechanical strength of the entire structure, but also make screw holes on the bridge to The use of screws to fix the control board on the bridge completely avoids the need to make a destructive opening to the back board to lock the control board, so it will not affect the mechanical strength of the structure. The above description is only a preferred embodiment of the present invention. Any equivalent changes and modifications made in accordance with the scope of patent application of the present invention are covered by the patent of the present invention. [Brief description of the drawings] Brief description of the drawings Figures 1-3 are schematic diagrams of the structure of the direct type backlight module in the conventional technology. 4 to 7 are schematic structural diagrams of a direct type backlight module in the present invention. 14 200528837 Symbol description of the drawings 10, 100 Direct-type backlight module 12 Metal back plate 14, 104 Front 16, 106 First edge 18, 108 Second edge 22, 24, 112, 114 Bevel 26, 28, 116, 118 Extension board 32, 122 Back 34, 36, 124, 126 Groove structure 38, 128 Protrusion 42 Screw iL 44 Opening hole 46, 136 Control board 48, 138 Flexible printed circuit board 50, 140 Housing 52, 144 Cover 102 Back plate 132 Bridge 134, 146 Screw 15