215

CAD/CAM in the Electronic Manufacturing Industry

Marco Tomljanovich Selenia-Autotrol Spa. Genova, Italy

In the electronic field, computerized algorithms and computer aided tools have received much more attention and operative acceptability than in any other manufacturing industry. As a consequence, a larger technical CAD/CAM integration has been achieved between the two traditionally separated worlds of design and production.

The transfer of methodological know-how from the latter to the former, in addition to the availability of stand-alone powerful engineering workstations, is now opening the way to a new innovative cycle which is likely to reshape to whole structure of the electronic systems industry.

The paper comments this innovation process by following the evolution of three of the basic manufacturing technologies. Trends driving future organizational changes will be drawn together with some parallelism toward the manufacturing mechanical industry.

Keywords: Computer Aided Design, CAD/CAM, CAE, PCB Layout, Wiring, Automatic Testing, Technology Evolution, China, IFIP Seminar.

. . . . . Marco Tomljanovich pionneered from ~ : : 1959 to 1963 software programming

and analysis as a full time job at the Computer Center and Servomecha- nism of the Engineering Faculty of the University of Bologna, where he ob- tained in 1962 one of the first degrees in Electronic Engineering.

During the military service he was Researcher on a part time basis at Fondazione U. Bordoni of P~rr in Rome, developing software in the Pat- tern Recognition area.

In 1964 he joined Selenia where, as Hardware and System Designer, he was involved in a number of projects and system designs with a strong emphasis on Data Handling and Data Visualization. In 1971 he accepted the responsibility of devel- oping capabilities for internal design automation in Selenia.

Since 1984 he has been working for Selenia-Autotrol (ITALCAD), a CAD/CAM European Company, which sells prod- ucts to the mechanical and AI~C markets. He is responsible for Strategic Planning and Engineering Management. M. Toml- janovich is member of s ~ and represents Italy in tFIP TC5.

North-Holland Computers in Industry 8 (1987) 215-225

1. Introduction

CAD/CAM is a well known acronym. CAD/CAM technologies are ga in ing more and more vis ibi l i ty as a l ead ing force dr iv ing p roduc t iv i ty in manufac - turing. In the e lect ronic sector the app l i ca t ion of these techniques in the des ign env i ronment are far more advanced than in any o ther indus t r ia l seg- ment . As a ma t t e r of fact, it is m y bel ief that the CAD/CAM in tegra t ion in the mechan ica l wor ld is a t least five years beh ind t ime. W i t h o u t d o u b t one of the ma in reasons for this resides in the fact tha t an e lect ronic p r o d u c t is far more easi ly mode l l ed than a mechanica l par t .

Circui t model l ing , behav iou r and faul t s imula- t ion, design ver i f ica t ion and circui t rea l iza t ion are n o w well k n o w n cAD/cAM pract ices , whils t solid mode l l ing is still in i ts infancy, and to lerances and fo rm features are stil l cons idered as research topics. A cri t ical review of wha t has been achieved, the p r o b l e m s solved and unsolved, and the analysis of the mode in which cAD/cAM inf luenced the way of do ing electronics can hopefu l ly b o t h in teres t the e lect ronic exper ts and suggest useful para l le - l isms to CAD/CAM users and developers active in o the r areas.

2. The Microelectronic Evolution and the Way of Doing Electronics

I t has been po in t e d ou t [2] that innova t ion in mechan ica l manufac tu r ing p roceeds in steps of 10 years and comple tes a cycle in 2 5 - 3 0 years. In- nova t ion in e lectronic manufac tu r ing exhibi ts a s imi lar bu t s l ighter fas ter behav iou r (and that is no t surpr is ing since the source of innova t ion is the same). There is in fact a na tu ra l posi t ive feedback mechan i sm be tween the evolu t ion of e lectronics and the i m p r o v e m e n t of the CAD/CAM technology which is the cause and effect of this evolut ion. In force of the changing technology, the sectors in which the e lec t ronic indus t ry was d iv ided in the 1950s are now prac t ica l ly reduced to only two:

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216 IFIP TC 5: SICA TMEM Computers in Industry

HARD'.#ARE

%0: DISCRETE COMPONENTS

SOFTWARe

%0: INTFOR~TED CIRCUITS

"70: L~I

Fig. i. Impact of technology evolution on the electronic industry market sectors.

functional devices (VLSI) and systems (Fig. 1). The corresponding suppliers are now sharing the market and are addressing more and more the same users (the overlapping area in Fig. 1).

The various evolutionary steps are a conse- quence of a process in which each level of compo- nent integration induces a modification on the design typology and therefore on the design criteria. In order to optimize the latter, the next level of component integration is pursued and the process is repeated again (Fig. 2). CAD/CAM tech- nologies are part of this and are playing a more and more active role in accelerating the evolution- ary process. The present transition to the subsys- tem level represents the completion of a first 30-year innovation cycle and marks the point be- yond which any further improvement will require CAD/CAM tools, expertise and automation.

In a rough schematization, the 30-year period can be subdivided into three successive steps of 10 years each. During each decade a specific manu- facturing technique was dominant and char- acterized the activities of research, implementa- tion, and exploitation of CAD/CAM efforts.

INTEGRATION PROJECT OPTIMIZATION LEVEL TYPOLOGY CRITERIA

I

I_...~DISCRETE )CIRCUITAL COMPONENTS DETERMINISTIC

)COMPONENTS COUNT I

I

I COMPONENTS

L__~NTEGRATED. >LOGIC ~ONNECTIVITY CIRCUIT DETERMINISTIC & TESTING

I i REDUNDANT [__,.JIICROELECTRONIC .)FUNCTIONAL ;,LOGICS

ADAPTIVE AUTODIAGNOSYS

Fig. 2. Innovative techniques and the way of doing electronics,

[lO6]

Computers in Industry M. Tomljanovich / CA D/CA M in Electronic Manufacturing Industry 217

These techniques are: - wiring; - printed circuit board (VCB) design; - logic simulation and testing.

2.1 Wiring

In 1950 the Gardner-Denver Company was founded and the wire-wrap technique became a feasible manufacturing alternative to wire solder- ing. The technique is still the most widely used method of automatic wiring. In it an automatic wiring tool wraps the stripped end of an insulated solid wire five to seven times around a square post to form a gas-tight bond. The post can be the terminal in a connection or a junction pin mounted on a PCB.

The wire-wrap technology marks the birth of CAM activities in the electronic manufacturing in- dustry. Its utilization involved in fact the prepara- tion of a punched tape, by the manufacturing personnel, in order to drive the NC machine.

Similar CAM operations were performed, during the same years, in the mechanical manufacturing industry.

As soon as the complexity of the wiring in- creased (very dense backpanels), it became natural however, to produce the required data using the service kindley offered by the Corporate EDP Center (to those manufacturing organizations de- void of ~DP Centers or unwilling to use them, the supplier offered the software available on any computer bureau). That opened the way to a possible collaboration with the Engineering De- partments, source of data; collaboration which became operative many years later due to the interest of the engineers to verify their design using a wire-wrapped socketed PCB.

The CAD CAM system (without the slash), still a dream in many mechanical manufacturing organi- zations, became therefore a reality at least in that context in the electronic industry 15 years ago. I am not affirming that a true integration has been achieved or that all problems (organizational, managerial, technical, etc.) disappeared at once. I would just like to point out that a common tech- nology, a common interest, a common methodol- ogy, was defined, verified and found mutually beneficial, and created the basis for mutual under- standing, expertise exchanging and management involment, between design and production.

Since then CAD/CAM activities in the wiring area have grown, embracing and incorporating other production technologies like solder-wrap, multiwire, stitch-wiring untill the latest microwire, microshield and unilayer II [7].

The related software became more and more sophisticated and capable of optimizing both the total wire length (automatic placement of connec- tors or ]c sockets) and the strategy of wiring routability. The machine tool choice differentiated in order to meet many different production re- quirements; suitable solutions were also found for testing the fabricated harness using the same wir- ing engineering data. At the end of the 1970s, the technology was mature and highly productive. In many organizations and for specific products the wiring technology satisfied the whole spectrum of manufacturing requirements. In those cases a true CIM, from the technical point of view, was achieved. Today the technology is going into obsolescence in favour of the multilayered PcB, which represent the logical evolutionary step.

2.2 PCB Design

In 1961 C.Y. Lee published his classic expansion wave algorithm for path connections which started the CAD research and development on PCB placing and routing.

Routing is part of the problem of circuit layout that is the problem of placing box-like modules in a frame and connecting them by wires according to a given set of rules. A typical layout problem can be described as a puzzle: many modules are to be placed in a given area so that they do not overlap. At the same time certain points called terminals must be connected by mutually non interfering wires (according to a given wiring list). The modules and the area are usually (but not always) rectangular in shape, and the wires must run with a certain clearance between the modules. The problem "in se" is very complex and drew the attention of many mathematic and computer gurus.

The implementation of the algorithm in a real industrial environment was however more com- plex because it required the solution of problems related to electrical constraints (power and ground lines, wiring capacitance of parallel paths), process reliability (plated through holes), process produc- tivity (reduction of unnecessary vias) and many

[io71

218 IFIP TC 5: SICA TMEM Computers in lndl~tly

other factors well known by production engineers, but not by the computer specialists and the ap- prentice sorcerer CAD/CAM enthusiasts. Neverthe- less, the design automation potentialities together with increasing engineering costs (and time) neces- sary to satisfy the request of denser and denser boards (the IC had arrived), forced again a positive collaboration between design, drawing depart- ments and production. The latter, not involved in the previous manually designed procedures were then requested to be part of the team because their technological know-how was needed to be embedded into the software. The aim of the CAD/CAM developers was to obtain productive tools capable of complying with the same rules, standard technological constraints set up by the previous production procedures; in other terms, to obtain what we call today an expert system. The commercial availability of turn-key products helped eventually to diffuse this cAD/cAM tech- nology into the electronic manufacturing industry replacing the old manual methodologies.

Today all medium and large organizations use

Table 2.

ELSAG, CAD-86

AVAILABLE RESOURCES (updated 1985}.

N. 3 WORK STATION, WO RY4NG 5000 HOUP-SIYEAR DISTPJBUTED ON FOLLOWING PHASES:

* 25% ELECTRICAL SCHEMATIC * 10% COM~W3NET8 I~-ACEMENT * 40% COI~IECnON8 ROUTING * 15% OUU~OTS GENERATION * 10% ~YS"TEM AND UBRAP, ES MANAGEMENT

B) N. 7 oPERATORS AND SYSTEM MANAGER, INVOLVED IN FOLLOWING ACTIVITIES:

* 30% SYSTEM AND LIBRARIES MANAGEMENT w ,~% PCB DESIGN * 20% O ~ S GENERATION

c:) SOFTWARE R:IOGRAMS FOR

* ~ INTERACTIVE DESIGN (COblPONENT R../K~IV~NT. ROUTING, DRAFTING) * OUI"RJ'T GENERATION (laOST-PROCE~OR8 TO PLOTTER. R-IOTOPLOTTER * UBRARIE8 AND ARCHIVES MANAGEMENT

NOTE; OUTPUT GENERATION AND UBRARIES & ARCHJVES HANAGEHEHT WAS DEV ELOREU BY INTERNAL RESOUP, CES

Table 1.

ELSAG, CAD-86

PCB PROJECT TOTAL COSTS

N.PROJECTS INTERNAL COSTS(K l) EXTERNALSERVIOE8 YEAR ~ CAD MANUAL O0~I~J(I~

1983 225 825 190 800

1984 375 600 180 $Z5

t965 300 600 180 375

PCB PROJECT ON CAD SYSTEM AND RELATED COSTS

N. PROJECTS OOHR,.EXPP( COST PER YEAR g REVISION8 N.LAYERS PROJECT (K~)

1883 50 3.5 6.4

1984 80 4.2 6

1895 120 4.7 5 7

CAD/CAM systems to design rcBs. The degree of automation varies according to the top manage- ment involvement, the skill and authority of the internal CAD/CAM group, the typology of products and the geographical location (country). Generally speaking, medium-large organizations maintain their own department whilst the small-medium ones use a CAD bureau. In any case there is a direct connection between the PcB design and the PCB manufacturing external suppliers (or internal facilities).

As a good example of the state of the art in a multi-technology user environment Tables 1-6 flash the most significant facts of the PCB design center in ELSAG SpA, Genova, Italy. ELSAG is part of the Selenia-Elsag group coordinating nine Italian companies whose products cover the whole spectrum of electronic applications. The rcas de- signed are used therefore in missiles, radar sys- tems (naval, ground or airborn), computers, tele- communication equipment, air traffic control sys- tems, NCS, robots etc.

2.3 Digital Simulators and A utomatic Testing

NOTE DESIGN RE';ISIO,NS ARE ABOLrf 30 - 40% OF TOTAL PROJECTS More than any other CAD/CAM technique, auto- matic testing created a deep change in the elec-

[lO8]

Computers in Industry

Table 3.

M. Tomljanovich / CAD~CAM in Electronic Manufacturing Industry 219

ELSAG, CAB-S6

P R O J E C T C O S T C O M P O S I T I O N

OO8T8 (KS)

N.52 P.C. Projects TotS.44/P.C..

! Project time ] 2.3Man-Year t N.52 P.C.. I 1 .G5 I I i Management & Support 1.14

t Solt~are Lioence 13.45

Capi!aI Co~ 12.2

N.90 P.C. Projects Tot.5.S2/P.C.

I Project Time 15 Man-Year I N.9O P.C. I I I- 1 Management. I & Su~Dom i I Soft~are I Uoence I i I I I Caoital Corn

I I I 12.1 i

4 I I0.82 l I !1.5

11.5 I I l I I

N.S6 P.C. Projects Tot.5.6t'P.C.

I Project Time 4 Man-Yee.r N.SG P.C.

i Management I & Suooom I" I Sofl',~'are i Ucenoe I ! I Ca~al Cost

I I I i 1 8 7 I I I i 10.85

I i71

-- 1 9 8 3 -- -- 1 9 8 4 -- -- 1 9 8 5 --

NOTE: P.C. PF~OJECT NUMBER. IS BASED ON DOUBLE'-EUROPE LEIANDARD P.C. WITH 100 tC (16 PINS)

tronic designing-manufacturing operations. Test- ing is the final phase both in the design and in the manufacturing process.

In the engineering department, testing is a de- sign activity. It is used, in general, to verify the respondence of the breadboard to the defined specifications (hereafter referred to as "specs"), but at the same time to fix experimentally a few parameters and very often to tune the original specs to a more cost-effective functionality. In the manufacturing environment, testing (final func- tional testing) is performed by skilled (and costly)

engineers capable of understanding engineering drawings and functional specs, who directly (using standard instrumentation) or indirectly (using ad hoc designed test stations) used it to verify the functionalities of the electronic assembly. While the testing activity in the design phase is always necessary, the production test is totally useless, and the related costs are a waste of money i f the product is error free. Automatic testing, promising to eliminate from 60 to 80% of the human related costs (depending on the fabricating process relia- bility), arose to the immediate interest of the

[1091

220 IFIP TC 5: S ICAT M E M

Table 4.

ELSAG, CAD-86

ACTIVITY, I N F O R M A T I O N F L O W , E Q U I P M E N T

ELECTRONIC: SCHEMATIC DIAGRAM PROJECT NET-UST

COMI:~3NENTS-LIST

PC-STATION

FOB P O LAYOUT WORK STATION PROJECT COMPONENTS Po8moN VAX BYSTEM

CONNECTION ROUTING

OLff~JTS MECHANICAL DRAWING R.OTrER GENERA.TION ASSEMBLY DRAWtNO

MASTERS FOR PHOTOPLOTTER - CIRCUIT METALLIZ ATION: - SOLDER.RESIST - SILKSCREEN AUTOMATIC DRILL PROGRAM

P.C. MANUFACTURING POB ASSEM'BUNG

NOTES a) Dioimzer$ we= been elimin4ded lot the input phases b) Plecement ro~in9 =tel ~ ere based oe irderaOIve programs

production managers. The first functional auto- matic test solution available on the market in the early 1970s employed the use of a fault simulator,

Table 5.

ELSAG, CAD-86

E V O L U T I O N A N D F U T U R E T A R G E T S

1975 - MANUAL DEVELOPMENT OF I~I,'B PROJECT - SINGLE OPARATORWORKING ON EACH PROJECT - P~OJECT LEAD TIME NOT COi~ATIBLE WITH UFE TIME OF PRODUCT - MANY CYCLES TO ERROR ELIMINATION - MEDIUM-LOW COMPLEXITY

1983 - INTRODUOTION OF C~D SYSTEM ON PCB PROJECT - CENTg~LIZED ACTIVITY, MANY ORERATOR~ ON THE SAME PROJEC:T - REDUCED LEAD TIME OF PROJECT DEVE LOI:~'tENT (ABOUT 80%) • VERY REUABt.E OUTPUTS - INCREASING OOMI:&.EXITY OF PCB (FROM 25 TO 6 - 8 LAYERS)

1990 - FULLY AUTOMATED POB DESIGN - ELECTRONIC AND PCB DESIGN INTEGRATION - TOTAL PROJECT TIME OPTI~ZATION - CENTRAUZED MARAGEMENT OF UBRARIES AND ARCHIVES

BY DATA-BASE S'Y~'rEM

Table 6.

Computet:s' m Industry

ELSAG, CAD-£6

O R G A N I Z A T I O N A N D M A N A G E M E N T P R O B t E M S

TARGETS:

* MINIMUM PRI-)3E/- T LE.AD TIME ACCURATE AND RELIABLE <)UTF~ iTS

* TECHN(_~LOGICAL UP-DATING * AC;CEPTABLE I: C)~TS

G U I D E L I N E S :

[:AD SYSTEM INTRODUCTION ON ALL DESIGN PHASES MAXIMUM SKILL OF OPERATORS EFFICIENT INTEGRATION WITH ELEDTRONIC; AND P c; PROJECT

* RTANDARD [IESI£~N-RULER_ DEFINITIE)N

O R G A N I Z A T I O N :

* COMPANY'S SERVICE {::ENTER WITH PROPER EGUIPMENT AND HUMAN RESCHJR!::ES * I;0 PFIOC'EDURES DERNITION * (~NTRALIZED MANAGEMENT OF LIBRARIES AND ARCHIVES ~" DIRECT CONNECTIuN WITH MANI IFACTURINO

S P E C I F I C P R O B L E M S

* HUMAN RESOURCES SELECTION AND WORKING GROUP GREATIC)N * EFFICIENT C'ONNECTION WITH ELECTRONIC PI~:MECT GROUP3 * C:uNTINOUS TECHNICAL UPDATE * EXCELLENT PERFORMANCE OF H/W AND SW

R E S U L T S ( O N 1 9 8 6 )

* MEAN PROJECT LEAD TIME 15 WORKING DAYS (INSTEAD 60 DAYS BEFL)RE) * IRRELEVANT PROJECT MISTAKES w MEDIUM COMR-EXITY OF PCB 45 LAYERS, MAXIMUM 12 LAYERS '~ UP-DKllNG ON TECHNOLOGICAL PROGRESS w REDIJC;TION OF TIME-MAN FROM 250 HOURS (TIRCAL PER PRO JEt2]) T/) BO HI-)URS

and an Automatic Test Equipment (ATE) embed: ding a minicomputer. A typical sequence of oper- ation was the following: Ca) The schematic diagram of the subassembly (a PCB) was coded using a special language. Four input sections were identified:

the net list the I /O list the gate list the model library of the component used.

(b) The compiled data structure was analyzed and a possible faults list was created. (c) A sequence of an input test pattern was sub- mitted by the user (an engineer), the fault s imula- tor was invoked and the detected faults were marked. The fault coverage was calculated. If not satisfactory, other input patterns were required. (d) The input pattern, the output simulated pat- tern and the fault dictionary were compressed into a test program which was driving the ATE.

The success of the functional ATE was slow to catch on, and even when this was achieved, did not last for long.

[1101

Computers in Industry M. Tomljanooich / CA D/CA M in Electronic Manufacturing Industry 221

The main reasons for this were: the novelty of the logic and fault simulators required expertise and capabilities not existent in normal industrial environments the increasing component complexity caused serious problems to the task of defining the component model the reluctance (or the hostility) of the designers to be allured by the potential advantages of the logic simulators the long cumbersome and error-prone test pro- gram production cycle the necessity to complicate the circuitry adding unneccessary I / o pins in order to increase the testability (perhaps the biggest drawback).

A number of techniques (signature analysis, scan design, built-in test; in circuits) have therefore been invented and are being experimented also today [3-5].

Simulation and testing is still far from being a mature CAD/CAM technology, but the testability is now a recognised designer's task. With automatic testing, the fact that a PCB or a subassembly can in any way be tested in production is not guaran- teed anymore. It very much depends upon the way in which it has been designed. The designer is therefore responsible for the testability and he has no other choice than to use a fault simulator. The consequences are: - designers are now much more interested in logic,

timing, switching, behaviour simulators - another piece of technological know-how has

been transferred from production to design.

(generally found in the most homogeneous compa- nies) no significant result has been achieved. The normal reasons for that are more or less the same used to explain the difficulty of mechanical ClM implementation: organizational, managerial, tech- nical, technological.

A solution however was proposed: instead of connecting existing isolated automated activities, try to integrate the various engineering functions in one multifaced computer aided tool and dupli- cate the same tool where required. The autono- mous engineering workstation (EWS), conceived at the beginning of this decade, offered the techno- logical framework on which the idea was imple- mented. Due to the extraordinary market accep- tability of the Personal Computer, there is now no doubt that the electronic industry is perfectly ca- pable to provide in a few years, at feasible costs, an EWS to every designer (and not only to elec- tronic designers). Softwarewise, the feasibility of CAD/CAM algorithms for layouting and simulation has been proven by the VLSI suppliers who exten- sively applied the CAD technology, starting in 1980 (see Fig. 4) [6]. The electronic manufacturing in- dustry is now exploiting the computer aided en-

Table 7.

(SELENIA 86)

AVAILABLE TECHNOLOGY IN SEMICUSTOM DESIGN

cmos

GATE ARRAY

3. The Engineering Workstation and the New Way of Doing Electronics

At the end of the 1970s in the electronic manufac- turing industry, CAD/CAM tools existed for virtu- ally every job in the process from online schematic capture to automatic component assembly (see as an example the situation in Selenia in 1981, Fig. 3). As automated design and production equipments rooted themselves more firmly in the company's operations, the need to link together the various automated islands became increasingly important in the overall effectiveness of CAD/CAM.

Many trials have been made in large organiza- tions to connect all the design activities into one integrated system. Apart from rare exceptions

1 . 5 MICRON 2K - 12K GATES

MSI MACROES, RAFI

STANDARD CELLS

FUNCTIONS : MSI, RAM, ROM, CPU, A/D IN CONTINUOS UPDATING

AUTO~IATIC CONVERSION FROM GATE ARRAYS TO STANDARD CELLS

ECL

300 - 3500 GATES FUrICTIOIIS : ['ISI, RAIl, ECL/TTL, TTL/ECL

BOTH TECIINOLOGIES ARE EVOLVING FAST

[111]

222 IFIP TC 5: SICA TMEM Cornpute~Y in Industry

gineering (CAE) workstation inside the engineering departments in order to design semicustom com- ponents. As an example Tables 7-10 show the experiences in Selenia. It is interesting to note that in contrast with the first utilization of CAD//CAM

techniques, ¢AE is not creating ad hoc internal centers or service bureaus, but it is going straight into the hands of the end users, namely the desig- ners.

Due to the peculiarity of the product (in- tegrated components), available internal facilities and services (drawing offices, manufacturing, etc.) are bypassed and the designers communicate di- rectly with the silicon foundries. Moreover, the new engineering tools (¢AE, WS) are preferably operated by young designers just coming from the university.

All together this can be considered a structure within a structure (just as a component is part of a Pen). Of course, once the component is designed and prototyped it has to be integrated into a PCB and therefore the necessary interfaces have to be maintained with the PCB design center, the Docu- mentation Departments and the manufacturing. However, the whole activity of automatic design verification and testing is now unquestionably in the hands of the Engineering Departments and not of the production. New CAE WSS are infact emerging, equipped with hardware logic evalua- tion units, capable of assisting designers in simula- tion and design verification, using physical chips as component models.

1972-75

IFROM-TO AND I |WIRING I r ~ PRODUCTION MANUAL ~t~POINTS L~OPTIh41ZATION L~TAPES I "~ NC h4ACHINU.

"I o0'o - TEO I l l l--f--I " T

WIRE-WRAP / |WIRING I STITCH-~IR J ITESTI~ l

197~-77 I IAUTO~iATIC I lCOMPONENT l

I~"E~ATIC I---~IP~CE~'~ k'----I L~YOOT l MANUAL I CODING J |ROUTING | ~LIBRARY )

(LAYOUT I I J I "1 ST LE) i " ' , i ,

i I I I IIINTERACTIUE I I i >NCDRILL .~ I J~-- ILAYOUTING L----~CAM TAPES I---~PHOTOPLOTTER i l PLACEM' ~ - - I JCOMPLETION ~ [---TCOMP. ASSV.

o,oI,I~iNO,j -I ~ i , , -

UNIFIED

CODING i 1972-7B

ISCHEMATIC ~ CODING I |(TESTING I J STYLE)

I TEST PATTERN

BACK ANNOTATION

TO SCHEMATIC ~' '~ (i)

• ItOGIC AND b i ---

1,AU,T r . . . . J .SIMOLA,O0, 'DIC,ION~RV' )1 I____.WNET LI,T I • , ITE T OOq

~ATE

Fig. 3. Design automation as implemented in the electronic manufacturing industry at the end of the 1970s e.g. Selenia (continued on next page).

[1121

Computers in Industry M. Tomljanovich / CA D/CA M in Electronic' Manufacturing Industry 223

1977-78

$ (I)

BriCK ANNOTATION (FROM LAYOUTING)

MANUhL (SCHEMATIC SKETCH)

$UPERSEEDED SCHEMATIC CODING (IYOUT & LOGIC)

'~ 0N-LINE i SCHEMATIC CAPTURE ~-

DEBAGGING

SCHEMATIC PLOTTED A2 SIZE

1975-79 SUPERSEEDED COMPONENT LIBRARIES (LAYOUT & LOGIC)

DATA BASE ADIYIINISTR.

ON-LINE USERS

CAD/CAM MATERIAL PURCHASING DOCUMENT Q.A. PRODUCTION PROD. NOR, PRO& MGR.

Fig, 3 (continued).

DESIGN (MAN/MONTH)

FUNCTION LOGIC

LAYOUT (NAN/MONTH)

LAYOUT

100 70 I I

40 ( 60 I

I10 I 50 I t

2[ I

10.3 I

CAD TECH,

PLACEMENT & ROUTING

FUNCTIONAL SIMULATORS

YEAR

1979

1980-81

1982-84

I10 121 I0,1 I I l l

I

I

LOGIC SYNTHESIS

1985-

Fig. 4. vLsI CAD generation.

[1131

224 IFIP TC 5." SICA T M E M

Table 8.

(SELE~II,~ 86)

SELENIA'S CHOICE

i . Ir~-HOUSE SEHICUSTOII DESIGII USING CAE WORI<STATIOU (Cr~OS ~;:ii

ECL)

2, LIMITATION TO GATE ARRAYS DUE TO :

, PRODUCTION VOLUHE/COST RATIO

. NOVELTY OF STANDARD CELLS

. COiIPLEX FUNCTION STILL NOT AVAILABLE ON CAE W,S,

4. Trends

The CAE ws is here to stay. Forces driving its increasing acceptance are: circuit complexity, en- gineering productivity, breadboard and prototype analysis and testing, requirement of customer- specific and application-specific Ic designs, sys- tem design, declining system prices.

Table 9.

(SELENIA 86)

CAE AND SEMICUSTOMS IMPAIr ON:

i, DESIGNERS GOOD ON YOUNGER (TYPICAL i MONTH OF TRAINING)

2, PROJECT A) OLD PRODUCT'S RETROFIT.

NO PARTICULAR PROBLEM TYPICAL 3 MONTHS

B) NEW DESIGN,

DIFFICULTIES DEPEND ON:

- SYSTEM DESIGN & SPECS DEFINITION

- GATE ARRAYS SIZE

- DESIGN INTERFERENCES TO/FROM OTHER PROJECTS

- LACK OF SYSTEM'S SIMULATING TOOLS

DOCUMENTATION AND PRODUCTION PROCEDURES,

: THREE MAIN AREAS

- PCB DESIGN : NET LIST AND BACK ANNOTATION

(PIN ASSIGNMENT)

- AUTOMATIC TESTING: INTERFACE TO ATE FUNCTIONAL TEST PROGRAMS AND COVERAGE, BED OF

NAILS LAYOUT, COMPONENT MODEL LIBRARY

- ARCHIVE AND TECHNICAL DOCUMENTATION

Table 10.

Computers zn lnd~Ytrv

(SELENIA B6)

STEPS ACTIVITIES

i r!CREI,;ENTAL

U~ST(HOURS)

SYSTEFi

DESIGil

IN HOUSE

CAE

SILICON

#OU~;DRY'S

CAD/CAH

I

INTERFACE SPECS AI!D REASIBILITY I

D#SIGN SPECS, ARCHITECTURE DESIGNI

SPECS, TECHNOLOGY, G.A. SIZE

PRED~SIGN, PIN ASSIGNMENT

TESTADILITY

IEST PATTERN (TP)

SCIIEMATIC & CODING

TP CODIIIG

SIPTACTIC DEBUG

I~CRE>IEt:TAL DESIGN VERIF.

GLOBAL DESIGU

PARAIZTRIC TEST

STRESS TEST

SUPPLIERS CODED NET LIST GENERA.

ACCEPTAtlCE TEST & VALIDATION

LAYOUT

POST-LAYOUT SI~IULATION

HASK TAPE

ENGINEERING SAMPLES

900

2150

2230

Specific forces driving engineers to acquire workstations are: • n e e d for dedicated resources • d e s i r e for control

d e m a n d for interactivity • p r i c e (assuming performance).

The PcB CAD WS and the ~c CAD WS will dominate their application market, complement- ing the CAE WS and allowing the integration into the design cycle down to the chip level design. At the same time, the level of hierarchy at which a CAD system will allow an engineer to begin a design will move up, approaching the conceptual level.

Silicon compilers are now emerging offering similar opportunities to VLSl designers. It is my opinion that at the end of the next innovation cycle the electronic manufacturing industry will be completely modified in its structure. The design center will be more and more a u t o n o m o u s while the "production" will be forced to change, config- uring itself, on the example of silicon foundries, as a number of highly automated and flexible s e r v i c e

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Computers in Industry M. Tomljanooich / CA D~ CA M in Electronic Manufacturing Industry 225

bureaus offering their aids at a predetermined price and delivery time.

5. Conclusion

CAD/CAM technologies are the cause and effect of the electronic evolution.

Wiring, layouting and testing have been the main areas of implementation of these technolo- gies. The successful automation of the related activities closes a 30 year innovation cycle which changed significantly the structural operations in- side the electronic manufacturing industry trans- ferring the major part of the knowledge and re- sponsibility of the "how" from the manufacturing side to the designing side, the latter being respon- sible and knowledgeable of the "what".

A new innovation cycle is starting now due to the appearance of the CAE workstation. It is fore- seeable that this tool will grow up to become a true "designer assistant". At the same time the industrial manufacturing environment will change from a sequential fragmented job-defined depart- ment into unstructured highly automated first-in first-out service bureaus.

Acknowledgments

I am indebted to Francesco Orsero (ELSAG), Eugenio Cavalcanti and Marco Canese (SELENIA)

for their important contributions. I am extremely grateful to Gerry Musgrave (Bunel Univ. ) and to my colleague Silvia Ansaldi for their support dur- ing the preparation of this paper.

years of the proceedings of the Design Automa- tion Conference (DAC). DAC has been held every year in June since 1964 (during the first years it was called a workshop). Major sources of publica- tions on layout, simulation and testing: A: Design Automation Conferences (IEEE and

ACM).

B: IEEE International symposium on circuits and systems.

C: IEEE International symposium on Fault Tolerant Computing (since 1971).

D: IEEE International Conference on Computer Aided Design (abbreviated ICCAD).

References

[1] J. Soukup: "Circuit Layout", in Proc. of the IEEE, vol. 69, n. 10, October 1981. (The paper is one of the best surveys on algorithm and contains a very comprehensive bibliogra- phy).

[2] J. Hatvany: "Dreams, Nightmares, Reality", Proc. of CA PE 83 (North Holland).

[3] T.H. Chen, M.A. Breuer: "Automatic Design for Testabil- ity via Testability Measures", IEEE Trans. on Computer Aided Design, vol. CAD-4; n. 1, January 85, pp. 3-11.

[4] T.W. Williams, K.P. Parker: "Design for Testability - A Survey". Proc. of the IEEE, vol. 71, n. 1, January 1983 (this paper is a good tutorial on the matter with an extensive bibliography).

[5] J. Niehans and C. Hefner: "Scan Techniques Aid Testing of Small System", in: Computer Design, September 1, 1986.

[6] H. Nomura: "Status, Trends and Impact of VLSI", VLSI '85, North Holland, E. Horbst Editor.

[7] Electronics, June 16, 1986, p. 54. [8] J. Vlietstra: "Computer Aided Printed Circuit Board De-

sign", in Computers in Indust~, Vol. 1, 1979 (this paper provides an overview of the various techniques for PCB design in use in industry).

Bibliography

For someone new to this field the best way to start would be to look through the last three or four

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