pcba生產(chǎn)注意事項(xiàng)2(存儲(chǔ)版)
【正文】 oto of damage due to a polycrystalline filament in a trick oxide device. SEM photo of a contact hole in the drain diffusion of an output transistor showing contact spiking. b. VT3091A ESD_HBM pad63(VCC2) fail The OM and SEM photograph of the poly burn out at pad63 (VCC2) for VT3091A device Pad63 (VCC2) Pad63 (VCC2) Poly layer 1. 人 (注意：人體感染靜電可能超過(guò) 3000V)。 產(chǎn)生源 濕度 10 20% RH 濕度 6590% RH 走過(guò)地毯 35,000 V 1,500 V 走過(guò)粗帆布 12,000 V 250 V 在工作檯工作 6,000 V 100 V 塑膠套中的紙張 7,000 V 600 V 拿起一只塑膠套 20,000 V 1,200 V 布套椅子 18,000V 15,00V 本表節(jié)錄自美國(guó)國(guó)防部，軍規(guī)手冊(cè) (MILSTD) 靜電可能產(chǎn)生的電位 ESD 的起因： Charged Device Model C approx. 3 pF R approx. 25 ohms (Ω) L approx. 10nH Human Body Model C = 100 pF R = 1500 ohms (Ω) Machine Model C = 200 pF L = μH ESD Model (1) The Human Body Model (HBM) is the ESD testing standard, andis defined in the MILSTD883C method . It representsa charged person touching agrounded device. It is the originalmodel used to simulate ESDdamage by a human, and is themost well known. EOS/ESDAssociation Standard –1993describes use of the HBM for device classification . (2) The Machine Model (MM) represents a worst case HBM. It provide more realisticsimulation of actual damage normally obtained from a person holding a tool. EOS/ESDAssociation Draft Standard –1993 describes use of the HBM for device classificationand has been released for ment. (3) The Charged Device Model (CDM) simulates the damage resulting from a charged devicecontacting a metal grounded surface. This failure mode is very damaging and is associatedwith automated handling equipment and use of dip tubes. EOS/ESD Association DraftStandard –1993 describes use of the CDM for device classification and has beenreleased for ment. 2. ESD保護(hù)線路不適當(dāng)。 c. 確保適當(dāng)?shù)卦O(shè)計(jì)可靠度應(yīng)力測(cè)試，特別是 BurnIn EOS的預(yù)防 d. 確認(rèn)排除 /降低大於 200 mv的雜訊。 e. 供給產(chǎn)品測(cè)試用的電源供應(yīng)器電壓輸出功能無(wú) 適當(dāng)之校驗(yàn)機(jī)制。 c. 電壓力測(cè)試設(shè)計(jì)不當(dāng)，致預(yù)燒 (BurnIn)對(duì)敏感零 件產(chǎn)生過(guò)應(yīng)力。 在長(zhǎng)脈波寬度和低電力時(shí) ，熱有足夠的時(shí)間流過(guò)氧化物，終致熔化電線。 VIA 2023年 RMA 分析，所有電子系統(tǒng)故障的 9% 是因 EOS和 ESD引起。 ： 主機(jī)板 BGA焊墊清理 → 鋼板對(duì)位，上錫膏 → 真空吸盤(pán)吸取 BGA→ 影像對(duì)位 (對(duì)準(zhǔn)焊墊 )→BGA 置放 → 將熱風(fēng)罩罩住 BGA → 進(jìn)行 Reflow → 完成流焊。拆封後超過(guò) 72小時(shí)尚未使用完的 IC元件，必須再烘烤 125186。 Reflow Profile The MountBack Profile of VT82C686B for VIA BGA Rework Machine ( Vendor : Martin , Model : MB1100 ) BGA (Rework)救回 程序流程圖： Start IC被使用過(guò)？ 目檢及 DVM 檢測(cè) (1) Popcorn Failure ? (2) VcctoGND O/S failure ? 烘烤 去錫球 清洗 植球 檢查 BGA重工植球合格？ 清洗 Bench
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