565953 五、 發明說明 ( 1) 本 發 明 涉 及 一 種電致發光體，特別是LED晶片，其係 依 據 串 請 專 利 範 圍第1項之前言而構成。此種LED晶片 中 — 種 活 性 之 層 堆疊具有以 A 1 x G a y I η ! x y N，0 S X $ 1 0 ^ y 1 _ a X -1 -y S 1爲主之半導體材料。 傳 統 之 LED 晶 片通常具有唯一之活性之層序列，其在 基 板 之 整 個 生 長 面之上方延伸。此種LED晶片在前側上 具 有 — 種 所 三田 δ冃 連 結墊（pad)以饋入電流且在基板之背面上 施 加 —* 整 面 之 接 觸金屬層，其中力求儘可能在活性之層 堆 疊 之 整 個 橫 向 之範圍上使經由LED晶片之電流通量擴 大 〇 除 了 垂 直 地 饋 入電流（其中活性之層堆疊以三明治形 式 配 置 在 二 個 接 觸區之間）之外，亦可形成一種晶片結 構 其 中 P 側 或 η側之接觸作用是由晶片之前側來達成 〇 當 基 板 對 該 活性之層堆疊是電性絕緣時，大部份都屬 上 述 情 況 〇 雖 然 活性 層 中丨 該光之產生過程之效率可高達接近1 0 0 % 5 此 種 LED 晶 丨片 之外部效率仍然較低。其困難性在於·· 使 平 面 式 生 長 之 活性半導體層（其具有高的折射率）中所 產 生 之 光 向 外 耦 合至折射率小很多之澆注材料中。通常 只 有 在 較 小 之 .〈了 體角中所產生之主光向外發出；其餘之 光 由 於 全 反 射 而 在半導體中反射回到半導體及澆注物質 之 間 之 界 面 層 且 在該處由於大部份被吸收而到達活性層 中 及 基 板 中 在 基板表面上及電性接觸元件上或連結墊 上 消 失 0 -3- 565953 五、發明說明 ( 2) 光 射 出性 較 佳 之 電 致 發 光 組 件 在 DE 199 11 7 1 7A1 中 已爲 人 所 知 〇 該 文件 中 所 揭 示 之 單 石 式 電 致 發 光 組 件 具 有一 個 基 板 > 其 上 設 置 多 個相 對 於 該 組 件 之 主 輻 射 方 向 而相 鄰 地 配 置 之 射 發 出 元 件 〇 較 佳 是 圓 柱 形 之 輻 射 發 出元 件 具 有 活 性 之 層 序 列 其 發 射 具 有 至 少 一 電 致 發 光之 Pi 1接面， -種所謂電流孔徑層（其 具 有 電 流 通 孔 以 限制 該 發 射 )及接觸層配置] 於! 該 發 射 區 之 後 〇 在 圓 柱 形輻 射 發 出 元 件 之 接 觸 層 上 配 置 環 形 之 各 接 觸 元 件 j 其 藉由 導 電 條 而 相 連 〇 XSEL 壞 形 接 觸 只 覆 蓋 該 Is 射 發 出 元 件 之上 側 之 區 域 由 於 車S 射 發 出 元 件 及 周 圍 介 質 之 間 之 邊 界面 上 之 全 反 射 使 只 有 很 少 之 輻 射 或 根 本 沒 有 輻 射 經 由 該已 被 覆 蓋 之 區 域 而 發 出 〇 由 先 刖 技 藝 開 始 > 本 發 明 之 目 的 是 提 供 一 種 電 致 發 光 組件 其 構 造 儘 可 能 簡 單 且 可 確 保 局 效 率 之 光 射 出 性 〇 此 § 的 以 具 有 串 請 專 利 範 圍 第 1 項 特 徵 之 電 致 發 光 組 件來 達 成 〇 本 發 明 有 利 之 其 它 形 式 描 述 在 串 Ξ主 δ円 專 利 範 圍 第2 至 1 : 5項中< ) 電 致 發 光 組 件 具 有 : 一 種 基 板 9 多 個 相 隔 開 而 配 置 在 基板 上 之 輻 射 發 出 元 件 ) 其 活 性 之 層 堆 疊 具 有 — 種 發 射 層（其具有橫向受限之發射區） ; 及 一 接 觸 元 件 其 配 置 在每 — 輻 射 發 出 元 件 上 0 各 接 觸 元 件 較 佳 是 配 置 在 輻 射 發出 元 件 之 中 央 且 寬 度 或 直 徑 小 於 該 車虽 射 發 出 元 件 之 寬 度或 直 徑 〇 此外 J 在 輻 射 發 出 元 件 之 局 度 已 固 定 時 > 須 選取 該 輻 射 發 出 元 件 之 寬 度 或 4- 直 徑 5 使 由 發 射 區 之 側 面 565953 五、 發 明說明 (3) 所 發 出 之 光 之主要成份直接經由輻 射發出元件之 側 面 而 發 出 〇 發 射 之 橫向尺寸等於接觸元件 之橫向尺寸。 這 在 發 射 區 及 接 觸 元件之間之活性層中電 荷載體之移動 性 較 小 時（例如， 在 :P 摻雜之 A1X G a y I η ! x yN，0 $ X $ 1 ，( y 1 且 X + y S 1時即屬此種情況）較佳是以下述方 式 達 成 ; 該 層 中 之 電流寬度須較小，使光 只在狹小之橫 向 丨品 中 產 生 於 該 接 觸元件下方。藉由本發 明之輻射發出 元 件 之 尺 寸 則 活 性之層堆疊內部中之反 射損耗可大大 地 減 少 5 此 乃 因 發 射至側面之光之最多成 份可直接由輻 射 發 出 元 件 之 側 面 發出。 該 車虽 射 發 出元件較佳是具有條形之結構（其寬 度 已 如 上 所 述 )或點狀之結構（其直徑已如上所述）。以下 爲 了 簡 單 之 故 只 提 及該輻射發出元件之寬 度及該接觸元 件 之 寬 度 因 此 在 輻射發出元件及/或接) 觸元件之點狀 之 結 構 中 是 指 其 直 徑。 特 別 是 當 活性之層堆疊之發射區 未直接位於半 導 體 表 面 之 下 方 時 ，則該輻射發出元件較 佳是以圓錐形 方 式 構 成 其 遠 離 基板之側面所具有之橫 切面較其靠近 該 接 觸 元 件 之 側 面 者還大。 該 車虽 射 發 出元件之尺寸須符合以 下之條件 0 < (b + b')/h< 2 cot(aj) 其 中 b 是 輻射發出元件之寬度， b '是接觸元件, 之： 寬J h 是: 幅： 射: 發出元件之高度，ατ是 -5- 由活性之層堆 疊 中 發 565953 五、發明說明（4) 出而至周圍介質中之光在全反射時之臨界角。 本發明之其它有利之特徵以下將依據較佳之實施例參 考所附之圖式來詳述。圖式簡單說明： 第1圖本發明電致發光組件之第一實施例之切面圖。 第2A至2C圖不同之輻射發出元件之切面圖，其可 用在第1圖之電致發光組件中。 第3圖另一形式之輻射發出元件之切面圖，其可用 在第1圖之電致發光組件中。 第4A，4B圖本發明之電致發光組件之俯視圖，其具 有點狀結構之輻射發出元件。 第5A至5 (:圖本發明之電致發光組件之俯視圖，其 具有條形結構之輻射發出元件。 第1圖之電致發光組件是一種LED晶片1，其所產生 之電磁輻射11之大部份是在主發射方向6中發出。主 發射方向6垂直於LED晶片1之主區段之平面。 LED晶片1具有基板2，其在以AUGaylnu yN， OgxSl，OSygl且x+y$l爲主之LED晶片1中具 有SiC或藍寶石（Saphir)。基板2上可選擇地（optionally) 設置一種Bragg反射層3，其使由發射區8中在基板2 之方向中所發出之光反射回去。這些Bragg反射層3已 爲此行之專家所熟知，此處不再詳述。 在Bragg反射層3上施加多個互相隔開而配置之輻射 發出元件4。如以下之第4,5圖中所示，這些輻射發出 元件之俯視圖具有點形之結構（例如，具有圓形’卵形 565953 五、發明說明（5) 或四角形之橫向橫切面）或條形之結構（例如’具有長方 形之橫向橫切面）。該輻射發出元件4之縱向中央軸5 平行於LED晶片1之主發射方向6。 該輻射發出元件4在可選擇性地設置之Bragg反射層 3上具有活性之層堆疊7，其包含一種發射層8 a及一種 橫向受限之發射區8(其具有至少一電致發光之pn接面）。 在特別優良之實施形式中，活性之層堆疊7由多個已 摻雜及/或未摻雜之AUGaylm — x-yN層（OSxSl’OSy S 1且x + y $ 1)所構成。但本發明之結構亦適用於以多 個 AlxGayIni-x-yP 層或 AlxGai-xAs 層（OSxSl，OSy si且χ+y^i)爲主或其它適當之m-v-或Π-VI -化合 物半導體爲主之活性之層堆疊。 接觸元件9及發射區8之間之區域較佳是由以Mg及 /或Zn(特別是以Mg)來進行p摻雜之AlxGaylrn-x-yN 材料（〇$ 1，OS yg 1且X + 1)所構成，其平行於 層之導電性須很小，使電流在饋入晶片中時該接觸元件 9及發射區8之間之區域中之電流寬度小於2 0 // m，特 別是在〇 · 1 // m至1 0 // m之間，使發射區8之橫向之橫 切面廣泛地限制於接觸元件9之垂直之投影面上。 活性之層堆疊7之發射區8中所產生之輻射1 1在側 面之傳送方向中經由輻射發出元件4之側面1 2而由活 性之層堆疊7進入周圍之介質（例如，一種可透過輻射 之塑料外罩（未顯示））中，LED晶片埋置於該介質中且該 介質例如由環氧樹脂，矽樹脂或其它適當之反應樹脂所 565953 五、 發明說明 (6) 構 成 〇 在 各 輻射發出元件4之間之中間 區 中亦可存在適 當 之 電 性 絕 緣用之可透過輻射之塡料。 在 各 車虽 射 發出元件4之上側上設有多 個 配置於中央之 接 觸 元 件 9 。各接觸元件9及輻射發出 元 件4之活性之 層 堆 疊 7 之 間至少在各接觸元件9之下 方 另外可施加一 接 觸 層 (未顯示）。如第4,5圖所示，各 接 觸元件9藉由 導 電 條 14而互相連接且與LED晶片1 之 前側上之連接 墊 1 5相連。 依據”該輻射發出元件4是 否 存在點狀結構 或 條 形 結 構 ”，則各接觸元件9可以接觸丨 黏或狹窄之接 觸 條 來 構 成 0 在 基 板 2 之遠離各輻射發出元件4之 此 側上例如在整 面 上 施 加 一 種接觸金屬層1 0。但亦可施 加 一已結構化之 接 觸 金 屬 層 ，其具有互相隔開之各接觸 面 ，這些接觸面 分 別 配 屬 於 一輻射發出元件4。 在 各 車虽 射 發出元件4之間在基板2上 或 在基板2上之 Bragg 反 | 1寸層3上施加一種反射層1 3， 以 便使輻射發出 元 件 4 所 發 出之向下傳送至基板2上之輻射1 1反射回 去 0 此 種 反 射層1 3在不具吸收性之基 板 2中具有優點 此 乃 因 反 射損耗及穿透損耗（其在射 入 及射出時發生 於 基 板 材 料 中）都可下降。 各 輻 射 發 出元件4例如可藉由Bragg 反 射層3及活性 之 層 堆 疊 7 以磊晶形式整面施加在基板 2 上且隨後以微 影 技 術 及 蝕 刻法而製成。另一方式是： 首 先在B r a g g反 射 層 〇 上 施 加一遮罩層，其中與輻射發 -8- 出 元件4之結構 565953 五、發明說明（7) 相對應之各開口須被蝕刻，然後在各開口中以磊晶形式 沈積多個活性層7。最後，藉由蝕刻又將該遮罩層去除。 本發明之電致發光組件之輻射發出元件4之準確之構造 及功能將依據不同之實施形式參考第2A至2C圖來描述。 在第2A圖所示之實施例中，發射區8在活性之層堆 疊7中直接設置在接觸元件9下方。在活性之層堆疊7 之局度h設疋期間’本發明中該已結構化之幅射發出兀 件4之寬度選擇成儘可能小。在第2 A圖之實施例中， 活性之層堆疊7之寬度b較佳是滿足以下之條件·· 0< (b + bf)/h< 2 cot(ax) 其中bf是接觸元件9之寬度，其較輻射發出元件4之寬 度b小很多，ατ是由活性之層堆疊7所發出而至周圍介 質中之輻射1 1全反射時之臨界角。ατ在GaN時是37。 ，使（b + b')/h之比應儘可能小於2.65。 在一些化合物半導體（例如，P摻雜之AlxGayIn丨-x-yN) 中，由於電荷載體之小之移動性使電流寬度很小，發射 區8因此只在發射層8a之垂直投影之區域上在接觸元 件9下方延伸，即，發射區8之橫向尺寸及寬度未較接 觸元件9之橫向尺寸及寬度b ’大很多。藉由活性層8之 上述尺寸，則由發射區8之側面所發出之光Π之最多 成份直接經由側面1 2發出。全反射未在側面1 2發生。 此外，由發射區8所產生之主fg射之大部份（即，c 〇 s (α τ) 二6 0 %)是在此種角度範圍中發出，使此種輻射直接（即 ，在活性之層堆疊7之上/下邊界層上未發生前述之反 565953 五、發明說明（9) 第2B圖顯示一種該輻射發出元件4，其中發射區8 未直接設在活性之層堆疊7之上邊緣或下邊緣上，而是 配置在活性之層堆疊7之中央。以和第2A圖中所示之 輻射發出元件4之構造相同之考慮爲基準，活性之層堆 疊7之寬度b在此種情況下應儘可能符合下列之較嚴格 之條件： 0 < (b + b，）/h < cot(aT) 以便產生相同之作用。 本發明所依據之原理是：在一已由活性之層堆疊7所 設定之高度h中須限制活性之層堆疊7之寬度b，使由 發射區8之側面所發出之光之儘可能多之成份直接由側 面12發出，此乃因輻射至周圍介質之邊界面上之入射角 小於全反射之臨界角。當發射區8配置在上邊界面及下 邊界面之間之活性之層堆疊7之任意之高度位置上時， 此行之專家因此可在cot(aT)及2cot(aT)之間輕易地調整 該輻射發出元件4之最佳尺寸之上限。 若發射區8在活性之層堆疊7中未直接設在接觸元件 9下方（如第2A圖所示）時，則一種圓錐形結構之輻射發 出元件4是有利的，如第3圖所示。輻射發出元件4之 側面1 2在本實施例中以傾斜之蝕刻面來形成，該活性 之層堆疊7之靠近該基板2之此側面較其靠近該接觸元 件9之此側面還大。在點狀結構之輻射發出元件4中， 這樣會造成一種截錐體形式之結構。 高度hi及h2(其指出該發射區8在活性之層堆疊7內 -11- 565953 五、發明說明（1〇) 部中之位置）通常由以磊晶方式施加而成之層8所設定 且另又可相加以得到該輻射發出元件4之高度（h h2 =h)。傾斜之側面1 2之結構寬度b及基準角度yS須藉 由側面1 2來調整以達成儘可能最佳化之光發出性，其 中該角度-及邊長比（ratio)較佳是須滿足 〇< (b+ b')/h< cot(aj) 此處當然須注意：全反射之臨界角ατ是由發射區8之 中點及側面1 2之中點之間之垂直連接線開始計算。 依據第4,5圖，現在說明LED晶片1之不同之其它形 式。第4A，4B圖以俯視圖之形式顯示點形結構之輻射發 出元件，第5A至5C圖以俯視圖之形式顯示條形結構之 輻射發出元件之不同之實施例。 以圓柱形或多面體構成之輻射發出元件4在其上側上 之中央分別具有一接觸點9。各接觸點9經由導電條1 4 而互相連接且亦與連結墊1 5相連接，連結墊1 5例如設 在LED晶片1之中央。輻射發出元件4定位在一（假想 之）六角形結構（第4A圖）或長方形結構（第4B圖）之各角 點上。第4A，4B圖中，明亮之圓形分別表示該輻射發出 元件（其具有平坦（或圓錐形）之側面）之上側。 在條形結構之輻射發出元件4之情況中，其以輻射狀 之形式由一配置在LED晶片1中央之連結墊1 5開始而 又分支成規則之幾何形式（第5 A圖）。爲了更淸楚之故， 第5圖中只顯不各接觸兀件9及相對應之連接條1 4 ;條 形延伸之各輻射發出元件4(其分別在電性連接元件9， -12- 565953 五、發明說明（η ) 1 4下方延伸）未繪出。 另一方式是：已結構化之條形之輻射發出元件4定位 成長方形之配置（第5B圖）或六角形之配置（第5C圖）° 此種輻射發出元件4之配置就全部之輻射發出元件4之 電流供應而言是有利的° 符號之說明 1 LED晶片 2 基板 3 Bragg反射層 4 輻射發出元件 5 縱向中央軸 6 主發射方向 7 層堆疊 8 發射區 8 a 發射層 9 接觸元件 11 輻射 12 側面 13 反射層 14 導電條 15 連結墊 -13-565953 V. Description of the invention (1) The present invention relates to an electroluminescence body, especially an LED chip, which is constituted according to the preamble of the first patent in the patent application. In this kind of LED chip, an active layer stack has a semiconductor material mainly composed of A 1 x G a y I η! X y N, 0 S X $ 1 0 ^ y 1 _ a X -1-y S 1. Traditional LED wafers usually have a single active layer sequence that extends above the entire growth surface of the substrate. This kind of LED chip has on the front side—a kind of Sanda δ 冃 pad to feed current and apply on the back of the substrate— * the entire contact metal layer, which strives to be stacked on the active layer as much as possible. In the horizontal range, the current flux through the LED chip is enlarged. In addition to feeding the current vertically (where the active layer stack is arranged between two contact areas in a sandwich form), a wafer structure can also be formed in which the P side The contact effect on the η side is achieved by the front side of the wafer. When the substrate is electrically insulated from the active layer stack, most of them are the above. Although the active layer 丨 the efficiency of the light generation process can be as high as Close to 100% 5 The external efficiency of this kind of LED chip is still low. The difficulty lies in the fact that the light generated in the planar active semiconductor layer (which has a high refractive index) is coupled out to a casting material with a much lower refractive index. Usually only in the smaller ones. The main light generated in the body angle is emitted outward; the rest of the light is reflected in the semiconductor due to total reflection back to the interface layer between the semiconductor and the casting substance and most of the It is absorbed and reaches the active layer and disappears in the substrate on the surface of the substrate and on the electrical contact element or on the connection pad. 0 -3- 565953 V. Description of the invention (2) The electroluminescent device with better light emission is in DE 199 11 7 1 7A1 is already known. The monolithic electroluminescence module disclosed in this document has a substrate > a plurality of emitting elements arranged adjacent to the main radiation direction of the module 〇Preferably, the cylindrical radiation emitting element has an active layer sequence whose emission has at least one electroluminescent Pi 1 junction, a so-called current aperture layer (which has a current through hole to limit the emission) and a contact layer configuration ] Yu! The launch zone After that, circular contact elements are arranged on the contact layer of the cylindrical radiation emitting element. They are connected by conductive strips. XSEL bad contact only covers the area above the Is emitting element due to the vehicle S emitting element and its surroundings. The total reflection on the boundary surface between the media allows little or no radiation to be emitted through the covered area. Beginning from the prior art > The object of the present invention is to provide an electroluminescent module with a structure As simple as possible and can ensure the efficiency of the light emission of the local efficiency. This § is achieved with an electroluminescent module having the first feature of the patent scope. Other advantageous forms of the present invention are described in the main scope of the patent 2 to 1: <5) The electroluminescent module has: a substrate 9 having a plurality of spokes spaced apart and arranged on the substrate Emitting element) its active layer stack has-an emitting layer (which has a laterally restricted emitting area); and a contact element arranged on each-the radiation emitting element 0 each contact element is preferably arranged on the radiation emitting element The center and the width or diameter is smaller than the width or diameter of the emission element of the car. In addition, when the radiation emission element is fixed, the width or 4-diameter of the radiation emission element must be selected. 565953 V. Description of the invention (3) The main component of the light emitted is emitted directly through the side of the radiation emitting element. The lateral dimension of the emission is equal to the lateral dimension of the contact element. This is when the mobility of the charge carrier in the active layer between the emitting region and the contact element is small (for example, at: P doped A1X G ay I η! X yN, 0 $ X $ 1, (y 1 and X This is the case when + y S 1) is preferably achieved in the following manner; the current width in this layer must be small, so that light is generated only under the contact element in a narrow lateral product. By the invention The size of the radiation emitting element can greatly reduce the reflection loss in the interior of the active layer stack. 5 This is because the most component of the light emitted to the side can be directly emitted from the side of the radiation emitting element. Although the car emits the element, it is preferably Structures with a stripe shape (the width of which has been described above) or dot-shaped structures (the diameter of which has already been described above). For the sake of simplicity, only the width of the radiation emitting element and the width of the contact element are described below. The point-like structure of the emitting element and / or the contact element refers to its diameter. Especially when the emission area of the active layer stack is not directly below the semiconductor surface, the radiation emitting element is preferably formed in a conical manner, and its side surface away from the substrate has a cross section that is closer to the side of the contact element. Those are still big. Although the size of the emission element of the car must meet the following conditions: 0 < (b + b ') / h < 2 cot (aj) where b is the width of the radiation emission element, b' is the contact element, and: width J h Is: Amplitude: Emission: The height of the emitting element, ατ is -5- from the active layer stack 565953 V. Description of the invention (4) The critical angle of the light from the outgoing medium to the surrounding medium during total reflection. Other advantageous features of the present invention will be described in detail below with reference to the attached drawings based on preferred embodiments. Brief description of the drawings: FIG. 1 is a cross-sectional view of a first embodiment of an electroluminescent device according to the present invention. 2A to 2C are cross-sectional views of different radiation emitting elements, which can be used in the electroluminescent module of Fig. 1. Fig. 3 is a sectional view of another form of the radiation emitting element, which can be used in the electroluminescent module of Fig. 1. Figs. 4A and 4B are top views of the electroluminescent module according to the present invention, which has a point-shaped radiation emitting element. FIGS. 5A to 5 (: FIG. 5 are plan views of the electroluminescent module of the present invention, which has a radiation emitting element having a strip structure. The electroluminescent module of FIG. 1 is an LED chip 1, which generates a large amount of electromagnetic radiation 11 Part of it is emitted in the main emission direction 6. The main emission direction 6 is perpendicular to the plane of the main section of the LED chip 1. The LED chip 1 has a substrate 2 which is at AUGaylnu yN, OgxSl, OSygl and x + y $ l as The main LED wafer 1 has SiC or Saphir. A substrate Bragg reflective layer 3 is optionally provided on the substrate 2 to reflect the light emitted from the emission region 8 in the direction of the substrate 2 back. These Bragg reflection layers 3 are well known by experts in this field, and will not be described in detail here. A plurality of spaced-apart radiation emitting elements 4 are applied to the Bragg reflection layers 3. As shown in Figures 4 and 5 below As shown, the top view of these radiation emitting elements has a point-like structure (for example, with a circular 'oval 565953 5. Invention Description (5) or a transverse cross-section of a quadrangle) or a bar-shaped structure (such as' has a rectangular transverse Cross section). This radiation emits elements The longitudinal central axis 5 of 4 is parallel to the main emission direction 6 of the LED chip 1. The radiation emitting element 4 has an active layer stack 7 on an optional Bragg reflection layer 3, which includes an emission layer 8a and an Transversely restricted emission region 8 (which has at least one electroluminescent pn junction). In a particularly good embodiment, the active layer stack 7 consists of a plurality of doped and / or undoped AUGaylm — x -yN layer (OSxSl'OSy S 1 and x + y $ 1). However, the structure of the present invention is also applicable to multiple AlxGayIni-x-yP layers or AlxGai-xAs layers (OSxSl, OSy si and χ + y ^ i) Active layer stack mainly dominated by other mv- or Π-VI-compound semiconductors. The area between the contact element 9 and the emission region 8 is preferably made of Mg and / or Zn (especially Made of Mg) p-doped AlxGaylrn-x-yN material (0 $ 1, OS yg 1 and X + 1), its conductivity parallel to the layer must be small, so that when the current is fed into the wafer The current width in the area between the contact element 9 and the emission area 8 is less than 2 0 // m, especially between 0 · 1 // m and 1 0 // m, which makes the emission area 8 horizontal The transverse cross-section is broadly limited to the vertical projection plane of the contact element 9. The radiation 1 1 generated in the emission region 8 of the active layer stack 7 passes through the side surface 12 of the radiation emitting element 4 in the direction of the side transmission. The active layer stack 7 enters the surrounding medium (for example, a radiation-permeable plastic cover (not shown)), the LED chip is buried in the medium and the medium is, for example, epoxy, silicone or other suitable Reaction Resin Institute 565953 V. Description of the invention (6) Composition 〇 Radiation-transmissive materials for proper electrical insulation may also be present in the intermediate region between the radiation emitting elements 4. A plurality of contact elements 9 arranged in the center are arranged on the upper side of each vehicle emission element 4. An active layer (not shown) may be applied between each contact element 9 and the active layer stack 7 of the radiation emitting element 4 at least below each contact element 9. As shown in Figs. 4 and 5, the contact elements 9 are connected to each other by the conductive strips 14 and to the connection pads 15 on the front side of the LED chip 1. According to "whether the radiation emitting element 4 has a dot-like structure or a stripe structure", each contact element 9 can contact a sticky or narrow contact strip to form 0. On this side of the substrate 2 away from each radiation emitting element 4, for example, A contact metal layer 10 is applied over the entire surface. However, it is also possible to apply a structured contact metal layer having contact surfaces spaced from each other, which contact surfaces are respectively assigned to a radiation emitting element 4. A reflective layer 1 3 is applied on the substrate 2 or on the Bragg reflection | 1 inch layer 3 on the substrate 2 between the emitting elements 4 of each vehicle so that the emission from the radiation emitting element 4 is transmitted downward to the substrate 2 The radiation above 1 1 is reflected back 0 This reflective layer 1 3 has advantages in the non-absorptive substrate 2 This is because the reflection loss and penetration loss (which occur in the substrate material when it is incident and emitted) can be reduced . Each radiation emitting element 4 can be made, for example, by applying a Bragg reflective layer 3 and an active layer stack 7 on the substrate 2 over the entire surface in an epitaxial manner, and then using lithography and etching. The other way is: First, a masking layer is applied on the Bragg reflection layer 0, in which the openings corresponding to the structure of the radiation emitting element 8-out 4 565953 V. The corresponding openings of the invention (7) must be etched, and then A plurality of active layers 7 are deposited in epitaxial form in each opening. Finally, the mask layer is removed by etching. The precise structure and function of the radiation emitting element 4 of the electroluminescent module of the present invention will be described with reference to FIGS. 2A to 2C according to different implementation forms. In the embodiment shown in Fig. 2A, the emission region 8 is disposed directly below the contact element 9 in the active layer stack 7. During the period h setting of the active layer stack 7, the width of the structured radiation emitting element 4 is selected to be as small as possible in the present invention. In the embodiment of FIG. 2A, the width b of the active layer stack 7 preferably satisfies the following conditions: 0 < (b + bf) / h < 2 cot (ax) where bf is the width of the contact element 9 , Which is much smaller than the width b of the radiation emitting element 4, ατ is the critical angle when the radiation 11 emitted from the active layer stack 7 is totally reflected in the surrounding medium. ατ is 37 in GaN. , So that the ratio of (b + b ') / h should be less than 2.65 as much as possible. In some compound semiconductors (for example, P-doped AlxGayIn 丨 -x-yN), due to the small mobility of the charge carrier, the current width is small, so the emission region 8 is therefore only on the region of the vertical projection of the emission layer 8a. The contact element 9 extends below, that is, the lateral dimension and width of the emission region 8 are not much larger than the lateral dimension and width b ′ of the contact element 9. With the above-mentioned dimensions of the active layer 8, the largest component of the light Π emitted from the side surface of the emission region 8 is directly emitted through the side surface 12. Total reflection did not occur on the side 1 2. In addition, most of the main fg radiation (ie, c 0s (α τ) 2 60%) generated by the emission area 8 is emitted in this range of angles, making this radiation directly (ie, in active The above-mentioned inversion does not occur on the upper / lower boundary layer of the layer stack 7 565953 V. Description of the invention (9) Figure 2B shows a radiation emitting element 4 in which the emission region 8 is not directly disposed on the active layer stack 7 On the edge or the lower edge, it is arranged in the center of the active layer stack 7. Based on the same considerations as the structure of the radiation emitting element 4 shown in FIG. 2A, the width b of the active layer stack 7 is such. The following stricter conditions should be met as far as possible: 0 < (b + b,) / h < cot (aT) so as to produce the same effect. The principle on which the present invention is based is: In the height h set by the layer stack 7, the width b of the active layer stack 7 must be limited so that as much of the component of the light emitted from the side of the emission region 8 as possible is directly emitted from the side 12, because of the radiation to the surrounding medium. The incident angle on the boundary surface is smaller than the critical angle of total reflection. When the emission area 8 is configured When the active layer stack 7 between the upper boundary surface and the lower boundary surface is at any height position, the experts in this line can therefore easily adjust the best of the radiation emitting element 4 between cot (aT) and 2cot (aT). The upper limit of the size. If the emission region 8 is not directly below the contact element 9 in the active layer stack 7 (as shown in FIG. 2A), a conical structure of the radiation emitting element 4 is advantageous, as in the third As shown in the figure, the side surface 12 of the radiation emitting element 4 is formed in this embodiment by an inclined etched surface. The side of the active layer stack 7 near the substrate 2 is more than the side of the active element stack 7 near the contact element 9. Large. In the point emitting structure of the radiation emitting element 4, this will result in a structure in the form of a truncated cone. Heights hi and h2 (which indicate that the emission area 8 is within the active layer stack 7-11-565953 V. Description of the invention The position in the (10) part) is usually set by the layer 8 formed by epitaxial method and can be added to obtain the height of the radiation emitting element 4 (h h2 = h). The inclined sides 1 2 of The structure width b and the reference angle yS must be adjusted by the side 1 2 to achieve In order to optimize the light emission as much as possible, the angle- and side-ratio is better to satisfy 0 < (b + b ') / h < cot (aj) Of course, it must be noted here: total reflection The critical angle ατ is calculated from the vertical connecting line between the midpoint of the emission area 8 and the midpoint of the side 12. According to Figs. 4 and 5, the other different forms of the LED chip 1 will now be described. 4A, 4B The figure shows the radiation emitting element of the point structure in a plan view, and FIGS. 5A to 5C show the different embodiments of the radiation emitting element of the bar structure in a plan view. The radiation emitting element 4 composed of a cylinder or a polyhedron Each center on the upper side has a contact point 9. Each contact point 9 is connected to each other via a conductive strip 14 and is also connected to a connection pad 15 which is provided in the center of the LED chip 1, for example. The radiation emitting element 4 is positioned at each corner of a (imaginary) hexagonal structure (Fig. 4A) or a rectangular structure (Fig. 4B). In Figures 4A and 4B, the bright circles represent the upper sides of the radiation emitting element (which has a flat (or conical) side). In the case of the strip-shaped radiation emitting element 4, it starts in a radial form from a connecting pad 15 arranged in the center of the LED chip 1 and branches into a regular geometric form (Fig. 5A). For better understanding, only the contact element 9 and the corresponding connection bar 14 are shown in FIG. 5; each radiation emitting element 4 extending in a strip shape (which is respectively in the electrical connection element 9, -12- 565953 V. The description of the invention (η) (extended below 4) is not shown. Another way is: the structured strip-shaped radiation emitting element 4 is positioned in a rectangular configuration (Figure 5B) or a hexagonal configuration (Figure 5C). The configuration of this radiation emitting element 4 emits all the radiation The current supply of element 4 is advantageous ° Explanation of symbols 1 LED chip 2 Substrate 3 Bragg reflective layer 4 Radiation emitting element 5 Vertical central axis 6 Main emission direction 7 Layer stack 8 Emission area 8 a Emission layer 9 Contact element 11 Radiation 12 Side 13 Reflective layer 14 Conductive strip 15 Connection pad-13-