laser鉆孔培訓(xùn)教材

1、12前言前言LASERLASER鉆孔簡(jiǎn)介鉆孔簡(jiǎn)介L(zhǎng)ASERLASER鉆機(jī)介紹鉆機(jī)介紹MicroviaMicrovia制作工藝制作工藝Microvia Microvia 常見(jiàn)缺陷分析常見(jiàn)缺陷分析3 隨著PCB向微型和高密度互連的方向發(fā)展，越來(lái)越多制板采用微導(dǎo)孔的連接方式實(shí)現(xiàn)高密度互連，而目前制作微導(dǎo)孔的主要方法是laser drill。如何利用現(xiàn)有鐳射鉆機(jī)制作出各種高質(zhì)量的microvia，是現(xiàn)在PCB制造的迫切任務(wù)。41、LASER分類100 nm 5th H, 4th H, 3rd H, Ar-Ion 2nd H, Nd:YAG Nd:YAG Nd:YAG Nd:YAG Nd:YAG Nd:

2、YLFWavelength212 nm266 nm355 nm488 nm532 nm1064 nmVISIBLEINFRAREDULTRAVIOLET1000 nm10,000 nm400 nm750 nm1321 nm光譜圖 激光類型主要包括紅外光紅外光和紫外光紫外光兩種；52、常見(jiàn)的LASER激發(fā)方式1)LASER 類型UV激發(fā)介質(zhì)YAG激發(fā)能量發(fā)光二極管代表機(jī)型：ESI 53202)LASER 類型 IR（RF-Radio Frequency）激發(fā)介質(zhì)密封CO2氣體激發(fā)能量高頻電壓代表機(jī)型：HITACHI LC-1C21E/1C3)LASER 類型 IR（TEA-Transverse

3、excited atmospheric橫波激勵(lì)）激發(fā)介質(zhì)外供CO2氣體激發(fā)能量高壓電極代表機(jī)型：SUMITOMO LAVIA 1000TW63.1、CO2的成孔原理利用紅外線的熱能，當(dāng)溫度升高或能量增加到一定程度后，如有機(jī)物的熔點(diǎn)、燃點(diǎn)或沸點(diǎn)時(shí)，則有機(jī)物分子的相互作用力或束縛力將大為減小到使有機(jī)物分子相互脫離成自由態(tài)或游離態(tài)，由于激光的不斷提供能量，而使有機(jī)分子逸出或者與空氣中的氧氣燃燒而成為二氧化碳或水氣體而散離去，由于激光是以一定直徑的紅外光束來(lái)加工的，因而形成微小孔。Absorptionand HeatingThermalConductionLightMeltingLiquidInter

4、faceVaporizationPlasma Production7固態(tài)Nd：YAG紫外激光器發(fā)射的是高能量的紫外光光束，利用其光學(xué)能(高能量光子)，破壞了有機(jī)物的分子鍵(如共價(jià)鍵)，金屬晶體(如金屬鍵)等，形成懸浮顆?；蛟訄F(tuán)、分子團(tuán)或原子、分子而逸散離出，最后形成盲孔。吸收吸收破壞分子破壞分子(原子原子)鍵鍵成孔成孔長(zhǎng)鏈大分子長(zhǎng)鏈大分子小粒子逃逸小粒子逃逸3.2、UV的成孔原理84、常見(jiàn)LASER的加工材料 Epoxy FR4 ARAMID COPPER BTv現(xiàn)已加工的介質(zhì)材料包括：RCC、1X1080、2X1080、2116、2X106、ARAMID9吸收率吸收率波長(zhǎng)波長(zhǎng) (um)Re

5、sinMatte CuGlassUVIRVISIBLE00.10.20.30.40.50.60.70.80.910.20.30.4 0.5 0.60.7 0.80.911.1 1.2各種材料都吸收樹脂吸收紅外光強(qiáng)玻璃反射銅反射由于不同材料對(duì)各類激光的吸收均不相同，導(dǎo)致LASER加工混合材料時(shí)的困難。4.1、不同材料對(duì)波長(zhǎng)的吸收情況（2000版本）104.2、不同材料對(duì)波長(zhǎng)的吸收情況（2001版本）11Aspect Ratio500 450 400 350 300 250 200 150 100 50 mmThru ViasBlind Vias10:11:1.1:1UV YAGCO2Photo-

6、viaMechanicalDrill5、各種方法加工孔直徑的范圍12我司現(xiàn)有 Laser 鉆機(jī)HITACHI LC-1C21E/1CLC-2F21SE/1CLC-2F212SE/2CLC-2G212E/2CLC-2G212BE/2CSUMITOMOLAVIA 1000TWESI53205330 ESI 5320v高頻率低功率脈沖v 固態(tài)激光激發(fā)裝置，無(wú)須外部供氣v “冷光”，產(chǎn)生熱量少Hitachiv RF Excited 密封氣體激發(fā)v 無(wú)須定期換氣v 每四小時(shí)需做精度校正SUMITOMO v 外部供氣v 須定期換氣v 加工時(shí)有能量檢測(cè)和補(bǔ)打功能13ESI UV Laser對(duì)位系統(tǒng)對(duì)位系統(tǒng)1

7、內(nèi)層靶標(biāo)對(duì)位內(nèi)層靶標(biāo)對(duì)位UV Laser刮內(nèi)層靶標(biāo)圖形刮內(nèi)層靶標(biāo)圖形定位補(bǔ)償方法4 points allow correction of x - y offset, rotation, scale, and keystone1415.7 mil Through Hole3 mil Hole8 mil Pad40 mil PadESI UV Laser對(duì)位系統(tǒng)對(duì)位系統(tǒng)2通孔對(duì)位通孔對(duì)位151.對(duì)位標(biāo)靶-圓形2.對(duì)位補(bǔ)償類似ESIHITACHI &SUMITOMO Laser對(duì)位系統(tǒng)對(duì)位系統(tǒng)Conformal Mask靶標(biāo)對(duì)位靶標(biāo)對(duì)位16Laser BeamGalvoUV LaserCO2

8、 Laser光學(xué)系統(tǒng)光學(xué)系統(tǒng)17Copper surface is cleaned and texturedESI UV Laser的鉆孔參數(shù)的鉆孔參數(shù):Step One: Drill CopperStep Two: Remove Dielectric25mm50 - 100mmFocused spotSmall spot sizeHigh energy densityDe-focused spotLarger spot sizeLower energy densityStop on inner copper layer18DielectricCopperPlanesPunchingDiele

9、ctricCopperPlanesTrepanningSpiralingDielectricCopperPlanesESI UV Laser的鉆孔參數(shù)的鉆孔參數(shù):19 Cycle Mode Burst ModeStep ModeHitachi &Sumitomo Laser的鉆孔參數(shù)的鉆孔參數(shù):即對(duì)在一個(gè)區(qū)域內(nèi)所有的孔進(jìn)行第一個(gè)脈沖加工，完畢后，再進(jìn)行第二個(gè)脈沖加工，如此類推。即對(duì)一個(gè)孔進(jìn)行所有的脈沖加工后，才對(duì)下個(gè)孔進(jìn)行加工。20鉆孔速度鉆孔速度 HITACHImax 1200脈沖/秒 SUMITOMOmax 1000脈沖/秒 ESI 15K30K70K脈沖/秒21一階盲孔：A、CO

10、2 laser drillB、CO2 laser direct drillC、UV direct drillD、UV+CO2 laser drill22二階盲孔(鉆Stacked via)：A、UV Direct drillB、UV + CO2C、Conformal mask + CO2 +UVD、UV + Conformal mask + CO223五、Microvia 缺陷分析 -缺陷類型缺陷類型 -產(chǎn)生原因和影響產(chǎn)生原因和影響 -解決方法解決方法24(1)Under Cut(2)Delaminate(4)Remained Glass Fiber(5)Remained Resin(8)Vo

11、id (7)Damage(6)Micro Crack Barrel Shaped Inner HoleLaser 盲孔缺陷盲孔缺陷25 PROBLEMS Under Cut Delaminate Cause and Effect Heat accumulation from RCC copper surface Impact to the RCC surface by Laser Beam (1)Under Cut(2)Delaminate26 Solution Short pulse width Reduce the pulse energyLASER Beam27 PROBLEMS Bar

12、rel Shaped Inner Hole Cause and Effect Reflection from hole bottom Incorrect position of Laser mode(single mode)to the hole Barrel Shaped Inner Hole28Reflection LASER Beam abSingle Mode29 Solution Short pulse(less than less) The best suited number of shots Multi-mode BeamSingle-modeMulti-mode(top-fl

13、at)30 PROBLEMS Remained Glass Fiber Cause and Effect Difference Nature against heat between resin and glass Solution High peak power processing Cycle-mode processing(4)Remained Glass Fiber31 PROBLEMS Remained Resin Cause and Effect a.Very thin smeared resin on the bottom of hole not reach sublimatio

14、n point(5)Remained Resin32b. Unsuitability of resin thickness c. Single-mode processing60m80m33d. Unsuitability of LASER pulse energy e. Incorrect position of LASER BeamAccuracy of XY tableAccuracy of ScannersAlignment Accuracy against PWB elasticityPWB warp 34 PROBLEMS Micro Crack Cause and Effect

15、The pressure from resin sublimation by LASER(6)Micro Crack35Solution -Short Pulse(less than less) -The best suited shape of LASER wave -The best pulse energy adapt to nature of material( Standard:about 10J/cm2,pulse width less than 1 us)36 PROBLEMS Damage Void Cause and Effect a.If the pulse width(irradiation time) is long, the temperature of substrate