học orcad

Chng 4: OrCAD Layout 9.2


Mc tiu cn t c: Layout 9.2 l mt chng trnh chuyn dng thit k mch in da theo s mch in

nguyn l c thit k t OrCad Capture. Sinh vin da vo filename.MNL chuyn sang Layout v t y sinh vin c th sp xp linh kin theo mun, c th v mch in theo phng php Manual hay Auto, c th v mch in 1 hoc 2 lp, cch ko Copper Pour .... Trong chng ny, sinh vin nm c cch thit k mch in v t y sinh vin c th vn dng mi tnh nng ca chng trnh Layout m thit k cc mch in thch hp theo nhu cu.

Kin thc c bn: Sinh vin cn phi c kin thc c bn v cc mn hc lin quan nh: K Thut Xung,

Linh Kin in T, Mch in T, K Thut S, K Thut Vi X L v phi s dng my vi tnh m c bn l h iu hnh Window.

Ti liu tham kho: [1] ng Minh Hong Thit K Mch In vi Layout 9 - NXB Thng k 2002. [2] Nguyn Khc Nguyn Bi Ging OrCAD Khoa Cng Ngh thng Tin H Cn Th - 2003

[3] Nguyn Ch Ngn Bi Ging OrCAD Khoa Cng Ngh thng Tin H Cn Th 2002

[4] Nguyn Vit Hng & Nhm cng tc V v Thit k mch in OrCAD NXB Nng 2004.

[5] Short Lectures on Internet (cc bi ging v OrCAD trn Internet)

Phn ni dung: Khi ng Orcad Layout To project mi Lin kt n footprint t footprint ln board mch nh dng v n nh kch thc board mch Sp xp linh kin trn board outline Xc nh s lp mch in cn v V kt ni (v t ng/v tay) Kim tra v in kt qu

Trn Hu Danh Trang 83

T Q L t t O CAD Chng 4: OrCAD Layout 9.2

S minh ho ton b qu trnh x l ca Layout

4.1. Khi ng Orcad Layout Chy file: Layout.exe

(Start All Programs Orcad Family Release 9.2 Layout ) hoc double click vo biu tng trn th chng ta s thy mt giao din xut hin

y c th xem l khung mn hnh tin chng trnh Layout chng ta c th rto mi, m, add vo hay xut ra cc tp tin bn v hon chnh.

By gi chng ta tm hiu mt s menu lnh c bn.

4.1.1. File

Cha cc lnh lin quan n vic to mi, m, add vo hay xut ra cc tp tin i tng vo Layout hay sang cc thnh phn khc (ca phn mm thit k mch khc nh Protel, PCAD PCB )

4.1.1.1. New

Nu chng ta chn New, chng ta s d dng to bng mch in mi vi File.MNL m chng ta to ra trong phn OrCAD Capture 9.2 chng 3. ( chng ta c th c th xem li chng 3 hiu r hn).

Khi ta chn lnh New t menu File, mn hnh hin khung thi Load Template File trong c cha tp tin cc board mch k thut mu vi board mch trng



hoc nhng board mch c cha sn cc linh kin c nh nu nh chng ta to board mch theo yu cu ca s chi tit mch in.

Sau , chng trnh Layout s yu cu bn to hoc m tp tin .MNL. Tp tin .MNL c to ra trong chng trnh OrCAD Capture (xem li chng 3)

4.1.1.2. Open

Lnh Open lit k tt c cc tp tin .MAX ang nm trong th mc hin hnh. m file.MAX chng ta ch cn chn file cn m sau chn Open l xong hay chng ta c th nhp double click chut vo file chn.

4.1.1.3. Import

Cho php chng ta m hay du nhp mt file c to ra t cc phn mm thit k mch khc nh Protel PCB, CadStar PCB

4.1.1.4. Export

Cho php chng ta chng ta xut file.MAX c to ra t OrCAD Layout sang cc phn mm thit k mch in khc nh CadStar PCB, Protel PCB

4.1.2. Tools

Menu Tools co cc chc nng sau:

4.1.2.1. Qun l th vin (Library Manager) Cho php chng ta edit hay to mi mt footprint ca mt linh

kin no . T y chng ta c th to hay su tp mt th vin footprint linh kin m chng ta hay s dng cho cc thit k sau ny ca mnh (khi chng ta chuyn v v thit k cc board mch)



4.1.2.2. OrCAD Capture

Cho php chng ta m chng trnh thit k mch nguyn l OrCAD Capture t chng trnh v board mch OrCAD Layout.

Ngoi ra cn cc chc nng khc nh SmartRout cho php chng ta v mch thng minh, Edit App Settings, Reload App Settings

4.2. To Project mi Chn File New chng ta s thy mt hp thoi xut hin nh hnh bn di

Nu chng ta thit k board mch bnh thng th chng ta load DEFAULT, cn nu chng ta mun thit k board mch ring theo mt hnh dng c th nh sound card LAN card cm trn chun PCI, hay mt card no cm trn chun ISA hay mt SDRAM, DDRAM th chng ta chn cc file template khc.

Ta cung co the oi mau cong nghe

(Technology template) sau khi vao moi

trng thiet ke bang cach file\ load (File

Technology template co dang *.tch ).

Sau khi chng ta chn file template cn load th mt hp thoi khc li xut hin yu cu chng ta m file.MNL m chng ta to ra trong phn OrCAD Capture (xem li chng 3).

Cch lm nh sau:

Chn file kt xut ca qu trnh o Netlist, trong trng hp ny t

l: NguonTT.MNL

Layout yu cu t tn file layout .max, mc nhin c tn ging tn project t (NguonTT.max)



Sau chn ng dn thch hp lu file.MAX. Nu cc linh kin trong mch thit k l cc linh kin mi v cha tng lin kt n th vin footprint ca Layout ln no th n yu cu chng ta phi lin kt n footprint. y l bc kh khn i hi chng ta phi cn thn, chng ta s tin hnh cch lm ny phn bn di

4.3. Lin kt n footprint

y l giai on kh, i hi kinh nghim lin kt cc Footprint n tng loi linh kin c s dng trong mch.

n vo Link Linh

kin cn lin kt

Chn tn footprint thch hp

Footprint

tng ng Lp li n ht cc linh kin trong mch

Cc th vin

Cc footprint trong

th vin tng ng

Mt s footprint thng dng: - Th vin TO: TO92 (trans. C828, C1815, C535, ) TO202 (trans. H1061, IC n p

h 78xxx, 79xxx ) - Th vin DIP100T: /W.300 (cc IC cm t 14-20 chn) /W.600 (cc IC cm t 24-40

chn )

- Th vin TM_CAP_P l footprint ca cc loi t in - Th vin TM_CYLND l footprint ca cc loi t in



- Th vin TM_DIODE l footprint ca cc loi diode hay Led.

4.4. t footprint trn board mch Sau khi lin kt cc footprint n ton b cc loi linh kin, Orcad t ng load cc

footprint nh hnh v

Lam viec vi footprint ( layout cua linh kien)

Trong phn ny chng ta cp n 2 vn : Tm kim linh kin v chnh sa footprint linh kin. Khi cc footprint c load thng thng chng khng ng nh yu cu ca ngi thit

k. Do , chng ta phi tm ng footprint cho ph hp vi tng loi linh kin thc t khi to ra board mch in sao cho ti u nht. Cch thc hin nh sau:

Chn footprint linh kin cn thay i trn board mch va load, sau click chut phi v chng ta s thy menu dc xut hin, tip theo chng ta chn Properties

Sau khi chng ta chn Properties th mt hp thoi xut hin cho chng ta chn loi footprint thch hp. Chng ta s thy vn ny nh hnh minh ha bn di.



Click chut vo y tm footprint thay th thch hp v chnh ta thy hp hi thoi xut hin

Chng ta click chut vo Footprint, sau chng ta s thy mt hp thoi cho chng ta chn footprint thch hp.

T hp thoi Select Footprint, n cho php ngi thit k la chn footprint thch hp hay theo thch ca mnh.

Tuy nhin, nu cc footprint c trong Select Footprint khng ph hp th chng ta phi to mi footprint cho ph hp v kch thc ca linh kin.

To mi mt linh kin (footprint).

M th vin linh kin ca layout : vo File \ library manager hoc Ctrl+I m

Hay s dng cng c trn thanh Tool Bar, sau khi chnh sa linh kin xong ta phi lu li (Save hay Save As)



to footprint mi hoc edit footprint trong Library

manager

Sau khi click chut vo Library Manager hay cng c trn thanh Tool Bar, chng ta s thy hp thoi xut hin

Nu chng ta mun to mt footprint mi hon ton th chng ta click chut vo Create New Footprint, cn nu to mt footprint mi thng qua vic Edit mt footprint linh kin c sn th chng ta chn th vin c cha footprint m chng ta cn thay i to thnh mt footprint mi, nu trong Libraries khng c th vin ta cn tm th chng ta Add th vin footprint mi vo v chng ta cn lu ch chn cc th vin footprint trong Layout m thi. Cc th vin ny chng ta c th Remove chng ra nu thy khng cn thit li s dng na v d nhin chng s khng b mt trong trng hp ny m chng vn cn nm trong th vin footprint ca Layout. Sau khi chng ta chn c footprint linh kin sao cho chng ta mt thi gian Edit nht. V d chng ta lm nh hnh trn, sau khi sa cha to ra mt footprint mi chng ta nn Save As v nu chng ta chn Save th n s lu footprint mi vo cng tn footprint c v lc tnh cht ca footprint c s khng cn ng nguyn bn cht ca chng na. Chng ta c th lu footprint mi nm trong th vin hin hnh hoc chng ta c th to ra mt th vin mi cho

ring

mnh.

chn ng dn lu th vin mi t tn th vin

mi

to th vin mi



Trong khi thit k mt footprint mi chng ta c th s dng cc cng c khc ca OrCad Layout to ra footprint theo mun v kch thc tu ....Chng hn c th dng cc cng c o dt nh: Dimension, Measurement trong menu Tool c th to chnh xc kch thc linh kin thc t.

xem thng tin v footprint ca linh kin ta vo:

Spreadsheet\Footprint

Sau khi click chut vo v chng ta s thy bng lit k cc footprint ca cc linh kin c trong board mch. C th i vi mch ngun trong thit k ny c lit k trong bng sau:

4.5. nh dng v kch thc board mch Nhp chut vo biu tng Obstacle Tool V bao hnh bn ngoi ca board mch Khi v xong ng bao khp kn, double click chut vo ng bao hay click

chut vo ng bao khi thy con tr c du + nh xut hin ri click phi chut, cch lm nh hnh bn di.

Sau chn Properties, xut hin ca s cho t rng ng bao nh sau



Thit lp n v o v hin th, n cng l n v th hin rng ca ng mch in (net) trong board mch. Mc ch ca vn ny l gip cho ngi thit k mch in kim sot c rng ca cc nets trong board mch cng nh kch thc ca board outline. Cch lm

c minh ha nh hnh bn di

Sau khi click chut vo Options\ System Setting (hay dng phm nng Ctrl+G). Chng ta s thy mt hp thoi xut hin, t y chng ta c th t cc n v thit k, n v hin th nh Mils, Inches, Microns, Millimeters hay Centimeter. Chng cng cho php cho chng ta thay i li hin th, li v, t li nu cn thit.



o kch thc board: Tool Dimension Select tool, sau o di v rng ng bao. Mc ch ca cch lm ny l cho ngi thit k bit c kch thc ca board mch mnh thit k c kch thc bao nhiu, c ln so vi kch thc thc t ca board mch in m mnh ang c t c cch iu chnh thch hp, sp xp li linh kin trong ng bao hp l vi mt khong cch hp l nht.Cch lm nh sau:

Chng ta

lu rng n v o khong cch ny c cng n v o vi n v c t trong Menu Options\System\Settings m chng ta va thc hin pha trn. Mun thay i n v hin th v cng nh n v o, chng ta cng vo Menu Options\System\Settings t li. Tuy nhin, n v trn board outline s khng t ng thay i theo, chng c th thay i chng ta phi vo Tool\Dimension\Select Tool hay New, sau click chut vo thc o khi thy con tr chut chuyn sang du + (nh) ri chng ta x dch th lc ny n v o s thay i theo n v o va t li.

Thit lp n v o cho bng thit k

Ve board outline



Chn cng c v board outline v v, sau double click ln board outline thit lp cc thng s , ta c hp thoi nh sau:

nh ngha Layer stack, ta chn Spreadsheet t Toolbar



Sau chng ta click chut vo layer chn lp v. Ta thy hp hi thoi xut hin:

thit lp li v ta vo Options System Setting v ta thy hp hi thoi sau y xut hin.

thit lp nhng lut v khong cch cho pads, tracks v vias. Ta chn Spreadsheet t Toolbar

Click chut vo Route Spacing, sau chn ko chut ngang qua lp mnh cn thc hin chc nng ny( c th ch mt lp TOP hay BOTTOM hoc c hai lp TOP v BOTTOM) v click chut phi sau t menu pop up chn Properties chng ta s thy



Thay i cc gi tr theo yu cu ca ngi v mch v ch n n v o ang s dng

nh ngha padsstack ta chn padstack trong Spreadsheet Ta lm tng t nh hnh bn di v s thy

Gi s ta chn VIA1 sau double click chut hay clcik chut phi ri chn Properties t menu pop upv chng ta s thy.

T y chng ta c th thay i hnh dng ca cc pin trong footprint v cc c tnh khc nh Non-Plated, Use For Test Point ...

t linh kin Sau khi thit lp cc thng s cho bn v, ta bt u sp xp linh kin. Trc khi t linh

kin trn bn v chng ta phi m bo rng trn bn v c board outline trn tt c cc lp v.



kim tra Board outline v nhng vng cm ta chn spreadsheet \ obstacles nh hnh bn di.

Lock linh kin (d dng cho vic sp xp linh kin trn bn v) v thay th linh kin (trng hp ta thit k sn footprint cho linh kin)

4.6. Sp xp linh kin ln board mch Nhp chut vo biu tng Component tool di chuyn linh kin no, ta nhp chut vo linh kin, sau , khi nh chut ra v

di chuyn th linh kin s c di chuyn theo. n v tr mun t linh kin, th nhp chut ln na Vic b tr linh kin l 1 trong nhng yu t quan trng nh hng n n nh, d v, thm m,

Board

outline

4.7. Xc nh s lp mch cn v Trong mc ny chng ta cn phi xc nh mch in chng ta cn v l bao nhiu lp. Trong OrCad Layout chng ta v c rt nhiu lp mch in nhng do trn th trng trong nc chng ta ch c bn mch in ti a l 2 lp v mt mt do hn ch v mt cng ngh nn cho d chng ta c v c mch in nhiu lp th chng ta cng khng th no ra mch c. Do chng ta ch chn s lp mch thch hp vi nhu cu thc t, tu theo mc phc tp ca mch m chng ta c th chn v mch in mt lp hoc hai lp


- n nh s lp mch in cn v ta chn View Spreadsheet Layer


V bng mch in ( mch ng) Trc khi ve nhng ng noi mach ta phai thiet lap nhng thuoc tnh

cua ng ve ( net properties), cho phep ve tren lp nao ( trng hp ve nhieu

lp), va mot so cac thong so khac. Thiet lap cac thuoc tnh cho ng noi

mach (ten, o rong)

Lu y :

- Ve ng Vcc va Gnd trc, phai co o rong ln hn tat ca cac ng con lai.

- Trong qua trnh ve ta co the click chuot phai e co the thay oi o rong, add via, free via, lock ng ve, thay oi loai via

V mch t ng (Autoroute) Layout s dung nhng ky thuat ve sweep, shove, interactive e tang cng

sc manh t ong ve va kha nang uyen chuyen ( flexibility)

Sau ay la nhng bc c ban e ve mach t

ong:

- Thiet lap nhng thuoc tnh cho ng ve (nets). - Kiem tra boardoutline, nh ngha via va li ve. - Ve ng Vcc va Gnd. - Ve trc nhng ng phc tap. - Load file chien thuat ve. - Chay autouter. - Optimize ng ve( s dung nhng cong cu

trong menu Auto).

Heres detail :

- Orcad c th v t ng trn s lp t. Tuy nhin, cc mch phc tp i hi nhiu thao tc v tay.

- v t ng: Chn Auto Autoroute Board - Orcad cho php t nhiu chin lc v khc nhau. Ngoi ra, trc khi v t ng

ta cn t cc thng s nh: rng ng v, khong cch ng - ng, ng - chn linh kin, S c cp phn cc k thut nng cao.



Lp BOTTOM V mch 1 lp

Sau khi v xong,ta cn kim tra li s ng n ca mch in v thc hin c chc nng ny chng ta click chut vo DRC trn thanh cng c. Nu mch chng ta v co li hoc cnh bo th s c nhng vng trn mu th chng ta phi sa ht tt c cc li ny th mch in chng ta thit k ra mi m bo khng b chm nhau.

V mch bng tay Vic v bng tay, tu thuc vo 3 ch v:

AutoPath Route Mode Add/Edit Route Mode Edit Segment Mode

Sau khi chn ch v thch hp, ta nhp chut vo ng v sa i hoc v ng mi t chn ny n chn khc. Thng thng, v t ng xong, i hi phi c thao tc chnh sa bng tay.


y l bn mch in c v t ng nhn khng p mt lm


4.8. In mch Layout ln giy trong/bng m in PCB layout va v, ta thc hin cc bc sau: - Chn Options Post Process Settings - Nhp chut phi vo lp mun in (v d lp BOTTOM), chn Preview - Chn File Print/plot - Chn options thch hp, OK

Click chut phi chn Preview t menu popup v chng ta vo FilePrint/Plot hoc Ctrl +P in

In thy tm ca pin linh kin d

dng khoan l mch in sau ny

Nu khng phi l my in mu th check

vo y

Nu b check ny nu mun in mch in theo to gc X, Y Ngc li th in board mch gia trang giy



Intertool communication

Layout co the lien lac hoac ket noi vi Capture hoac mot so cong cu thiet

ke mach ien khac e co the kiem tra tnh chnh xac cua mach ien sau khi hoan

tat.

Mot trong nhng kha nang noi bat cua Layout la khi ta chon mot oi

tng trong Capture th oi tng tng ng trong Layout se sang len va ngc lai.

Chc nng ny gip cho ngi thit k bit c linh kin mnh sp xp xem chng nm ngay v tr mong mong mun hay cha.

Trc khi s dung cong cu Intercool communication trong Capture, ta phai bat

che o ITC trong Capture nh sau : Options \ Preferences



Qui trnh to mch ng

In PCB layout

ln giy trong/bng m

To bng la (mt n)

In la ln bng ng

Ra mch bng ho cht

Khoan l, ph xanh,

Hon tt mch in

To th vin footprint trong Orcad layout - Khi ng Orcad layout - Chn Tools Library Manager Create New Footprint t tn cho

footprint.

- thm Pin mi, nhp chut phi, chn New - Sau khi t xong tt c cc chn, lu li footprint - Cn lu n t l li v

nh dng rng ng mch in



- Nhp chut vo View Spreadsheet, chn Nets - Chn Width tng ng vi Net Name trong bng Nets

rng ng Min Max (1 inche = 1000 mils)

nh dng khong cch cc ng v - Nhp chut vo Options, chn Global Spacing - Chn v t khong cch thch hp.

- Vic t cc khong cch ny cng vi rng ng s nh hng ln n vic v mch. V d, ng mch c th khng xuyn qua 2 chn IC c,

- Ph thuc cng ngh lm mch in, Cc ch quan trng khi v bng mch thit k: Trong phn Layout chng ta ch n 2 vn chnh l v mch in t ng v v

mch in bng tay (manual), nhng cho d l v bng cch no i chng na chng ta cng c mt s ch sau:

1. bit c kch thc ca bng mch in th ta vo Tool/Dimension/New (hoc select tool),ri ra mn hnh v mch ta ch cn nhp chut tri v khi thy c hnh 2 mi tn hng ra v ta ko chut i v mun o n on no th ta nhp chut tri th thanh thc o s hin th ra gi tr o c, nhng gi tr ny mc nhin l Mils do mun i v dng mm hoc cm th ta vo Options/systems setting v chn n v cn o. V



by gi gi tr ny vn cha thay i, mun thay di th ta ch cn nhp chut vo thc o trn bn mch in ri nhp chut li ln na xc nh.

2. Phi v ng vin bao quanh bn mch in kim sot ng v, linh kin khi v s khng b vt ra ngoi gii hn cho php. lm c iu ny ta lm nh sau:

Vo Tool/Obstacle/new (hoc select tool) hay nhp chut vo Obstacle Tool trn Menu lnh, ri chn 0 Global layer (c mu vng).Nhp chut tri v khi thy con tr l du cng nh hn. Sau ko chut c mun dng ti im no th nhp chut tri. Khi im u v im cui gp nhau th ta nhp chut phi chn End Command kt thc.

3. t chin lc v mch in t ng ta vo trong menu Options/ Route Strategies/Route Sweep. chn v lp trn bao nhiu % v lp di bao nhiu %.

4. Vo Options chn Global Spacing chn khong cch gia cc track to track, via to via, track to via, track to pad, via to pad

5. To Copper pour cho bn mch in khi thit k xong, mc ch ca vn ny l chng nhiu cho mch in. C th ko lp ph ny i vi VCC hay vi GND. Cch lm nh sau:

T menu Tool/Obstacle/properties ( nu to ng vin bao quanh bn mch ri) hoc l Tool/Obstacle/new i vi trng hp cha to ng vin cho bn mch in v ta phi v ng vin bao quanh bn mch. Khi v xong, nhp chut tri khi thy con tr co hnh du + nh th nhp chut tri chn Properties. Sau khi trn mn hnh xut hin hp thoi Edit Obstacle. K tip chng ta chn Obstacle Type chn Copper pour, chn Obstacle layer chn lp cn ph copper pour ( c th l TOP hay BOTTOM) cn Net Attachment th chn l GND hay VCC ty theo chng ta mun ph theo GND hay VCC Cn Hatch Pattern th ta chn l Line hay Cross Hatching hay Soild ri chn OK. Sau chn tip OK Sau chn ESC hoc nhp chut phi ri chn End Command hoc Finish. Thi chng ta s c mt bn mch in ph Copper pour.

6. Kch hot kim tra li khi v mch in vo menu Tool/erro chn select tool kch hot by li. Mun xem li th chn menu Tool/erro/select from spreadsheet hoc cng c th chn menu Auto/Design rule check kim tra li, hoc kch chut vo menu lnh Design Rule Check.

7. In cc linh kin trn board mch mt trn ca board mch thun tin cho vic gn linh kin v sau th ta lm nh sau:

Vo menu Options/Post Process Settings th hp hithoi xut hin. Sau chn Plot Output File name l *.AST nhp chut phi v chn Preview xem cc linh kin mt trn ca board mch. By gi ch cn ta in file ny ra thy cc linh kin c sp xp mt trnca board mch.

8. Sau khi v xong board mch in, by gi Layout trong Orcad c h tr chc nng filter ti u ha lm cho mch gn v ti u nht ( trong c hai ch v t ng v v bng tay u s dng c tnh nng ny v ch co trong Layout v Layout Plus). Bng cch chn Menu Auto\ Cleanup Design hoc c th vo t Menu Auto\Refresh/minimize conections .

9. thay i rng ca ng mch ta chn ng mch cn thay i rng (lc ny ta c th ang ch v manual hay kt thc vic v t ng, ch cn chnh rng ng mch cho ph hp) tac th chn mode autopath Route hoc Add/edit



route hoc Edit segment v nhn phm W th c mt hp hi thoi hin ra cho chng ta chn c th thay i c th l c segment, net hoc conections.

10. Ta c th chn mt khi mch ring l trn mt board v. Nhm kim tra cc chin thut v chn v ti u board mch in v sau ny. Vo menu View\Zoom DRC/Route Box ri linh kin ( ta c th thay i kch thc ca DRC/Route Box hin hnh, di n hoc c th t kch c ca DRC/Route box bng mouse v phng to v chuyn mt v tr khc). Sau vo Menu Auto\Autoroute\DRC/Route Box v khi mch chn. Cn nu mun Unroute khi mch v trn th ta lm ngc li vo menu Auto\Unroute\DRC/Route Box khng v.

Chng 4: OrCAD Layout 9.2 4.1. Khi ng Orcad Layout 4.1.1. File 4.1.1.1. New 4.1.1.2. Open 4.1.1.3. Import 4.1.1.4. Export 4.1.2. Tools 4.1.2.1. Qun l th vin (Library Manager) 4.1.2.2. OrCAD Capture 4.2. To Project mi 4.3. Lin kt n footprint 4.4. t footprint trn board mch 4.5. nh dng v kch thc board mch 4.6. Sp xp linh kin ln board mch 4.7. Xc nh s lp mch

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