PH LC THI TUYN SINH C13KHOA IN IN TCLB NGHIN CU KHOA HCTp. H Ch Minh, ngy 30 thng 03 nm 2015PH LC THI TUYN C13HNG DN THI CNG BOARD MSP430G2553 Bi vit ny nm trong ph lc tuyn sinh kha C13 ca PIF, trnh by c th cc bc thi cng board MSP430G2553 bng phng php i. Cc bn nn xem thm TUT Hng dn thc hin mch in bng phng php th cng trn website ca PIF. Bi ny c trnh by bi kinh nghim ca 1 thnh vin CLB, vn phong v quan im ca c nhn, tp th s khng thm chu trch nhim v ni dung bi ny.Bc 1: o kch thc mch v tin hnh ct board ngDa vo layout ta c th bit chnh xc kch thc ca mch. T ta ct board tng ng vi cc s o . Ngoi ra, nn d ra khong 2mm n 3mm d thao tc khi i ( d nhiu qu lm mch to v xu).Dng dao ct mch v thc k 1 ng thng c nh lm chun. Sau theo ng m ct mnh xung.

Lm i lm li nhiu ln, khi thy vt ct su th c th b theo ng ct. Sau khi ct mch su khong 1/2 n 2/3 dy board, ta lt mt sau ct tip theo ng , trnh trng hp ch ct 1 mt khi b mt sau s khng p. Ch l lm bc ny tht kho, khng th board ng s xu x v mo xo. Tuy yu cu l lm mch cho chy nhng cc bn cng nn n dung nhan ca n mt cht.

Board c ly lm mu y l board mch 1 lp thng thng.Cc bn no c nh lm board siu p bng board si thy tinh (nhn trong sut rt p) th ch rng loi vt liu ny rt cng, rt kh ct, nn chu kh luyn c tay mt cht.

Bc 2: Ch nhm b mt board ng va ctDng giy nhm ch cho b mt board ng sng bng. Lp ng ngoi khng kh s b oxy ho, kh bm mc khi i v kh bm ch khi hn. Do ta cn lm sch board.

Xem hnh bn so snh gia board ng c ch sch vi tm board ban u.

Bc 3: C nh bn in vo board ngTa p mt c mc in vo phn ta va mi ch sch ca board ng.

C gng sp xp sao cho ngay ngn. Sau ta c nh li bng cch gp n theo cc mp board nh hnh bn.

Bc 4: i mchLm bc ny th cc bn phi thc s kin nhn, vn dng c bp :D mnh vo mi ngc ngch ca b mt. i u, tp trung i k cc mp v ch ny thng rt kh dnh mc ( cng l l do khi thit k Layout bn nn v thm ng vin xung quanh mp bo).Cng khng nn i lu qu, nhit qu cao c th lm bong lp ng ln.

Ta i n khi thy b mt ming giy en u v chy mc (i vi board ny thi gian i khong 10 15 pht, nu i lu hn m vn cha thy bm mc, th c th nguyn nhn l tm ng ca bn cha c lm sch, hoc ngi ta in ln cho bn t giy no ch khng phi giy thuc chuyn ny cng thnh thong xy ra trong trng hp ny bn s phi lm li :D).

Trong bi ny tc gi ly v d giy thuc i, cc bn cng c th i bng giy decal, hay giy glossy g .Bc 5: Ngm ncTa ngm c board ng (cn giy) vo nc, khng bc trc tip v rt d b t net. C th i mt lc cho giy mc ra. Dng ngn ci t vo b mt bc ht lp giy. Sau ta dng khn lau kh.Trnh dng mng tay co ra v rt d lm bay mt cc ng mc.

Hnh trn: board sau khi bc ht lp giy, cn ang t nc, ta s dng khn lau kh (hoc chi vo ci qun :D)

Bc 6: V li cc ng b tSau khi lau kh, bn s thy board nh hnh di y. Kim tra k xem c ng mch no b t khng. Gi s c ng mch b t, ta dng bt v li.Bt s dng y l loi bt lng thng dng vit ln a CD (khng bay mc, khng phi loi bt vit bng u nh). Nn dng bt mu en, bt ca Thin Long cho cht lng tt hn cc loi bt nhm nh khc.Ti y th cc bn c th vn dng mi kh nng hi ha ca mnh vo. C th v chim c, hoa he hay mt vi ng vt khc vo cho board mch thm sinh ng (v ch no trng tri nha). Trnh v linh tinh vo phn mch, sau ny ng hi sao mch khng chy :D

Bc 7: Ngm ha chtHo cht xi y l bt FeCl3 (ngoi ch gi l bt st). Bn ho bt ny vo nc, trc ht n s tan trong nc (phn ng ny sinh nhit v si bt c c, nu ln u xi n bn cng ng hong lon =)) ).Sau da vo kin thc Ho t i cn st li t hi thi i hc, th bn s bit rng Cu tc dng vi Fe3+ s sinh ra mt ci g , tm li l s phn ng ht Cu trn board ca bn, ngoi tr nhng phn b mc en che li s cha phn ng.Vn l, dung dch hp dn ny khng tt cho sc kho v s pht trin ca tr s sinh v tr nh, khi thao tc bn cn trnh ngi, ht, tip xc vi n v trnh n bn ln da (c th eo khu trang, gng tay cao su).Tin hnh ngm mch, bn c th dng gng tay cao su hoc:+ Khoan 1 l nh ngay gc ca board mch, lun dy in hoc dy g vo cm. Sau tin hnh ngm ha cht. qu trnh ngm khng mt nhiu thi gian, c th b nhiu bt st v lc u board trong dung dch (ng lc mnh qu ko nc bn ra ngoi).

Trong qu trnh ngm, lu lu ko board ln dm xem ng b phn ng ht cha (ch dm k, ko cn st ng lm dnh cc ng mch vi nhau).Tu nng bt st, tu s nhit tnh lc board ca bn m thi gian ngm mch c th di ngn khc nhau. Tuy nhin nu bn board ngm lu qu, th cc ng mch di lp mc mu en ca bn cng s b n mn ht lun.Cui cng sau khi ng b phn ng ht, ta ra board qua nc sch.Dung dch bt Fe nu c bn ra sn nh bn phi di nc ngay, lu s khng ch ra c na (s b m la, hoc b ch nh ui ra khi phng tr).

Hnh: board sau khi ngm xongX l nc ngm mch:Nc bt st c th ti s dng, c th lu tr trong h nha / thy tinh, y np kn khng bay mi nh hng n sc khe cng ng.Nu khng cn lu tr, b sau mi ln xi (trnh tr nh, bn cng phng ung nhm :D) th lu : khng dng nc ny ti cy, khng di trc tip nc ny vo bn cu hay ng x nc. Bn nn ha long dung dch ny vi tht nhiu nc ri hy . V ngay lp tc sau di thm nhiu nc na pha long n v gip n mau tri.Bc 8: Lm sch mc bm trn mchDng giy nhm ch cho bay ht lp mc (c th va ngm nc va ch cho l). Khi cc ng ng s hin ln. Cn phi ch tht sch lp mc, nu khng cc bc sau bn s lnh hu qu.

Sau khi ch mc bay ht, em y s rng ngi v chi la nh th ny:

Cn thn dm li tng t mt trn board, xem th c ng mch no dnh li vi nhau (do Cu cha c ra ht hay khng). Nu c, dng dao ct mch (hay ci g cng c) co b lp Cu d i, cho tht sch s, nu khng bn s lnh hu qu khi cm in.Bc 9: Qut nha thng lng pha xng thmQut ln b mt board ng 1 lp nha thng pha xng thm. Sau em phi kh trong 1 khong thi gian. Mc ch ca vic ny nhm gip bo v lp ng trnh b oxi ha lm en mch, dn in khng tt. Ngoi ra, nha thng gip cho qu trnh hn d dng hn.Lu :+ Nu qut nha thng bc ny, bn phi board kh ri mi lm tip. lm nha thng kh nhanh, bn c th em board phi nng, dng bn i h nng (p mt nha, tc mt khng c nha thng ln bn i nh), hoc dng my sy tc / my kh h nng. + Nu nhanh tay nhanh chn, bn c th khoan l, hn mch xong xui ri mi trt nha thng ln. Tt nhin, i nha thng kh ri mi dng. Nu nha thng c qu, c th 1-2 ngy mi kh c, bn nn pha nha thng va phi thi. Nu chn phng n ny, bn nn ph lp nha thng mng va, nu nhiu nha thng qu, n chy vo cc chn IC c th lm IC tip xc khng tt (v chy sai).Nu quyt nh qut nha thng sau cng, th cc bc tip theo bn phi lm tht nhanh nhn, v board ng ngoi khng kh rt nhanh b oxy ho (s b en, xu).Nu thao tc trc, bn ch mc khng sch, sau khi ph nha thng mc s chy loang ra, ra mu en en hoc xanh xanh nhn rt gm.+ Mt s bn xi nha thng pha sn ngoi tim m mua phi loi lm sau khi ph xong nhn xanh l nh ru mc kh l gm.

Bc 10: Khoan lDng mi khoan thch hp khoan vo cc l m trn layout quy nh. Trnh khoan l qu to lm bay pad ng, khi hn s rt kh khn.Khi khoan, nh khoan va , trnh qu dn ti ci l to ng, lm xu mch. Cng vic ny cn 1 bn tay chc khe, thao tc chnh xc. Tay run th ch c cp t m n. V th cc bn nn tp luyn tay chn thng xuyn khoan cho tt nh =))

Nn k board ln cao d khoan.

Board sau khi khoan l xong.Bc 11: Hn linh kinTin hnh hn cc linh kin vo. y l bc kh khn nht. Khi hn ta nn trnh ht ch. Truyn thuyt k rng, ht ch s gip ta sng th thm 1 vi nm. V vy, cc bn nn eo khu trang khi hn hoc kim ch no khng gian thong ng, trnh hn trong phng my lnh.Ngoi ra, dng ch xn c thnh phn thic cao cng c hi hn. Hin nay c loi thic hn NoPb (khng ch) s m bo hn cho sc khe tng lai con em bn (nu c).Ta phi hn theo trnh t t thp ti cao. Ngha l hn cc linh kin c phn nh ln thp nht trc. y ta s hn in tr, diode trc.

Sau l n t pi v led C tip tc hn cho n khi hon tt.

12 7 5 38 6 4Mi hn t tiu chun phi tha cc iu kin sau y:+ Chc chn+ t hao ch+ Sng bng+ Ch khng b chy loang theo ng mch.

Xem hnh bn v phn tch cc mi hn:S 1: Mi hn b lem ch ln ng mch v hi d ch.S 2: Tuy c b lem 1 cht nhng tm chp nhn c :D.S 3: tm n.S 5: khoan run tay nn b d 1 l. S 4, 7: Cha ch ht pad ng ca chn linh kin.S 6: d ch.S 8: hu qu ca vic khoan lch l, lm mt pad ng nn mi hn khng bao trn quanh chn linh kin c.

V y l kt qu:

Ngoi ra, bn no mun i mch bng giy can thay v giy thuc, c th xem thm bi sau:http://www.payitforward.edu.vn/forum/threads/781/Nu mun i lun lp ch SSTOP cho pro (khuyn khch i SSTOP bng giy can, s p hn)http://www.payitforward.edu.vn/forum/threads/778/

Tm s ca tc gi:Nu lm mch ln u (1 vi ln u :D) m mch mnh khng hon thnh c, hay lm xong nhng hi b xu th cc bn cng khng cn phi e ngi. Lm nhiu ln s gip bn rt ra c nhiu kinh nghim (lm sai cng nhiu cng c nhiu kinh nghim :D).Bi vit ny c vit da vo kinh nghim xng mu rt ra c t nhng ln lm mch xu quc, test th khng chy c ca tc gi. V vy, nu cc bn lm mch cn cha c p, mch cha chy ng vi yu cu th vn c hy mnh dn em sn phm mnh ln cho cc anh ch trong CLB xem xt v sa cha. Cc anh ch trong CLB s h tr cng nh a ra nhng li khuyn cho cc bn mt cch tn tnh nht. CLB lun hoan nghnh nhng bn n lc ht mnh, khng ngi kh khn hon thnh cng vic ca mnh. Chc cc bn thnh cng.

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