Kombinat Mikroelektronik Erfurt


VEB Kombinat Mikroelektronik Erfurt was an important manufacturer of active electronic components in East Germany. It should not be confused with the more well-known VEB Kombinat Robotron Dresden which used integrated circuits from Kombinat Mikroelektronik in its computers. The trademark RFT was used for components from Kombinat Mikroelektronik, as well as for most electronic products from East Germany.

History

The Kombinat Mikroelektronik Erfurt was formed in 1978 when the VVB Bauelemente und Vakuumtechnik was split into VEB Kombinat Elektronische Bauelemente Teltow for passive electronic components and VEB Kombinat Mikroelektronik Erfurt for active electronic components. However, the history of many of the individual plants reaches back further, in some cases to before the Second World War. In 1971 the first integrated circuits had been manufactured — the D100C by Halbleiterwerk Frankfurt and the U101D by Funkwerk Erfurt. To put this into perspective, the first TTL circuits went into production in the US 10 years and at Siemens in West Germany 5 years before East Germany. The first microprocessor, the U808D, followed in 1978, 6 years after the Intel 8008 that the U808 was cloned from. Further milestones were the U880 in 1980 and the first 16-bit microprocessor U8000 in 1984. The ruling Socialist Unity Party of Germany had identified the development of the microelectronics sector as a primary goal. Huge sums were spent in order to catch up to the West — between 1986 and 1990 about 7% of the country-wide industry investment. However, this effort was hampered by several factors: the general inefficiency of the planned economy, insufficient cooperation with other Comecon countries, and western CoCom export restrictions that prevented the importation of semiconductor manufacturing equipment. Nonetheless, the development program achieved samples of a 1Mbit dRAM chip in 1988 and a 32-bit processor in 1989. Mikroelektronik "Karl Marx" Erfurt achieved a feature size of 3 µm on 4-inch wafers in 1984, 2.5 µm in 1988, and 1.5 µm on 5-inch wafers in 1990. In 1989, Halbleiterwerk Frankfurt produced 110 million integrated circuits and Mikroelektronik "Karl Marx" Erfurt produced 35 million.

After 1990

Following the German reunification, Kombinat Mikroelektronik was dissolved and operated for a time as a holding company under the name PTC-electronic AG which was 100% owned by the Treuhandanstalt. Most products from Kombinat Mikroelektronik could not be sold on the world market and many plants were liquidated by the Treuhandanstalt in 1991.
The Thesys Gesellschaft für Mikroelektronik mbH and the X-FAB Gesellschaft zur Fertigung von Wafern mbH were created in 1992 from parts of VEB Mikroelektronik "Karl Marx" Erfurt. In 1999 both companies were combined as X-FAB Semiconductor Foundries GmbH. In 2007, X-FAB took over another former part of Kombinat Mikroelektronik: the foundry of the former VEB ZFTM Dresden. ZFTM Dresden had become Zentrum Mikroelektronik Dresden GmbH in 1993. After several ownership changes and the sale of the foundry to X-FAB, ZMD was renamed to ZMDI and the remaining fab-less design house was ultimately sold to Integrated Device Technology in 2015. Not far from Dresden in Freiberg, the wafer production of VEB Spurenmetalle continued through Siltronic and Freiberger Compound Materials GmbH. Together with TU Dresden, VEB ZFTM and VEB Spurenmetalle formed the foundation for Silicon Saxony, a cluster of microelectronics companies that came to include new fabs by Siemens and AMD.
The Frankfurt region did not fare as well. VEB Halbleiterwerk was succeeded, in turn, by Halbleiterwerk GmbH, System Microelectronic Innovation GmbH, Silicon Microelectronic Integration GmbH, Megaxess GmbH Deutschland, and Microtechnology Services Frankfurt GmbH, each with less employees than its predecessor. The website of MSF disappeared around 2009. Construction on a new semiconductor plant, Communicant Semiconductor Technologies, had started already but this endeavour collapsed in 2003. Only IHP, the research institute that had supported VEB Halbleiterwerk, remained after that.
At VEB Werk für Fernsehelektronik Berlin, the production of electronic tubes and optoelectronics was shut down step by step until only the relatively modern manufacturing of colour CRTs remained. In 1993 the CRT manufacturing was taken over by Samsung SDI. In 2005, when LCD screens largely replaced CRTs, the plant was shut down entirely. Of VEB Mikroelektronik "Karl Liebknecht" Stahnsdorf, only the small group developing silicon pressure sensors survived the liquidation in 1992 and was acquired by Endress+Hauser. In Neuhaus am Rennweg, the SMD packaging of VEB Mikroelektronik "Anna Seghers" became part of Zetex Semiconductors which was in turn acquired by Diodes Incorporated.

Divisions

The Kombinat consisted of a number of plants across East Germany :
Two plants from Kombinat Mikroelektronik were moved to VEB Kombinat "Carl Zeiss" Jena in 1986:
The East German clock and watch industry formed part of the Kombinat Mikroelektronik as the Leitbereich Uhren with a number of plants:

Microprocessors

The U830, U8032, U8047, and U320C20 were manufactured by ZFTM Dresden while all other processors came from Mikroelektronik "Karl Marx" Erfurt.

Consumer goods

Semiconductor designation

The type designations for both discrete semiconductor devices and integrated circuits were specified in state standard TGL 38015. The designations for discrete semiconductors are similar to the Pro Electron specification and are discussed there.
The type designation for integrated circuits initially consisted of one letter for the basic type and temperature range, a three-digit type number, and one letter for the package type. Over time this proved inflexible and the plants started adding letters for further temperature ranges, speed classes, etc.. In order to curb these somewhat uncoordinated extensions and also out of a desire to keep the type numbers in common with international equivalents, the standard was revised in 1986. Almost arbitrary type numbers were allowed now, including additional letters in the type number if the international equivalent had them. The temperature range was added as a separate letter at the end. A 2-digit number could follow the temperature letter in order to indicate the maximum clock frequency of a microprocessor or the access time of a memory circuit. Existing type designations were kept even if they did not fully conform to the new standard. Integrated circuits that did not meet the official specifications, were sold as hobbyist versions. More often than not, these were the only versions available to hobbyists. Before 1987 the hobbyist versions were assigned separate basic type letters while keeping the type number. From 1987 onwards, S1 was appended to the unchanged type designation for hobbyist versions.
New package type letters were added in 1987 while the previously defined letters remained unchanged.
PackageDescriptionExample
CCeramic dual in-line package
DPlastic dual in-line package
EPlastic dual in-line package with tabs for heat sink attachment
FCeramic Flatpack or Quad Flat Package
GPlastic Flatpack or Quad Flat Package U131G
HMulti-leaded power package for horizontal mountingA2030H
KDual in-line package with fixed heat sinkA210K
MPlastic Quad in-line package
NPlastic SOT package, especially SOT54B589N
PPlastic chip carrier package
RCeramic chip carrier package
SSmall Outline Package B2765SG
VMulti-leaded power package for vertical mountingB3370V
XBare chip without packageU132X

In the early years all integrated circuit packages were manufactured with a spacing of 2.5 mm between pins just like in the Soviet Union and unlike the 2.54 mm spacing used in the West. Over time more and more circuits with 16 or more pins were produced with a 2.54 mm spacing. Where a certain circuit was available with either of the two spacings, TGL 38015 required that the version with a 2.54 mm spacing be marked with the letter "Z" on the package.
The temperature range letter was introduced only in 1987 and therefore not many integrated circuits were labelled with it.
LetterRangeExample
ARange not listed in TGL 38015B3040DA
B+5 °C to +55 °C
C0 °C to +70 °C
D-10 °C to +70 °CA1670VD
E-10 °C to +85 °CB467GE
F-25 °C to +70 °CL220CF
G-25 °C to +85 °CB2600DG
K-40 °C to +85 °CU74HCT03DK

Beside the type designation the manufacturing date was printed on integrated circuits. From 1978 onwards the IEC 60062 letter and digit code was used for manufacturing date.
Following the dissolution of Kombinat Mikroelektronik in 1990, the plants in Frankfurt and Erfurt kept using the East German integrated circuit designation until 1992 while ZMD in Dresden applied a slightly modified version until about 2005.
The East German integrated circuit designation was also used by Componentes Electrónicos "Ernesto Che Guevara" in Pinar del Río in the late 1980s.