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Production method for aluminum beam leads on ceramic substrates
18
WORLD
ABSTRACTS
ON MICROELECTRONICS
M O S technology isn't as complicated as it appears at first glance. Once the terms and technologies, "buzzwords" and processes are defined and placed in their proper perspective, the picture will start to clear.
5. M I C R O E L E C T R O N I C S
AND RELIABILITY
L i n e a r IC m a r k e t i n f e r m e n t . L. CURaAN. Electronics, 11 October (1971), p. 97. Reshuffle caused by recession and saturation of op amp sector pushes designers into consumer, computer interface, other special-purpose ICs.
DESIGN AND CONSTRUCTION
Production m e t h o d for a l u m i n u m b e a m leads on c e r a m i c substrates. R. E. MCMAHoN, F. J. BACHNER, R. A. COHEN, W. S. FRANKLIN and J. D. IMPEY. Proc. 21st Electronic Components Conf., Washington DC, USA, 10-12 May (1971), p. 96. A reproducible and reliable method has been developed for manufacturing aluminum beam leads on ceramic substrates. These beam leads are intended for ultrasonic bonding to the aluminum pads on commercially available integrated circuit chips. This developmental work has been aimed toward the production of a 30-stage T T L shift register in a beam leaded substrate configuration which is planar and eliminates the need for flying-wire bonds. The method employs the injection of water soluble silicates preloaded with aluminum oxide into preformed apertures in the substrate. When dried, these silicates have the strength and low vapor pressure necessary for the subsequent vacuum metallization and photolithographic operations. The silicates are contained in the substrate by a film of sheet photosensitive polymer applied over the entire surface of the substrate. After the silicates are dried, the photosensitive polymer is exposed and developed, leaving a film only over the silicate-filled apertures. The substrate is then metaUized with approximately 0.0005 in. of aluminum in a multifilament evaporator. At this point the silicates are removed by insertion of the substrate in deionized water and placing it in a cavitation mode using a commercial ultrasonic cleaner. The silicates are water soluble, and the presence of aluminum oxide particles helps to accelerate the cavitation process. After removing the silicates, the aluminum is photolithographically formed into the interconnection and beam-lead pattern, and the photo-resist and remaining sheet polymer removed. The prepared beams require no further processing and can be bonded directly to the chip bonding pads using an ultrasonic wire bonder modified with a flat bonding wedge. Bond strengths in excess of 10 g have been obtained and strengths are remarkably uniform.
Packaging t e c h n i q u e s for m o d e r n m i c r o e l e c trouics e q u i p m e n t . F. A. ROBm~TSON. Electronics Power, October (1971), p. 406. It is not easy for a designer to decide the form that electronic circuit packages should assume; this article explains packaging problems in the past, and presents a pattern of design for the future.
Buried w i r e m u l t i l a y e r c e r a m i c s . B. M. HARGIS. Solid State Technol., May (1971), p. 47. Multilayer structures are helping the microcircuit industry shorten electrical paths to reduce switching times. Ceramic packages and substrates with their hermetic and heat
transfer properties meet the design requirements of today's microcircuits. Design criteria and methods of producing these packages and substrates are described along with a discussion of refractory and noble metals used in the manufacturing process.
An o v e r v i e w of p h o t o m a s l d n g t e c h n o l o g y in the past d e c a d e . A. J. O'MALLEY. Solid State Technol., June (1971), p. 57. The development of the step and repeat microreduction photographic process for producing photomasks is described in the context of manufacturing requirements during the past ten years. The technical problems associated with the introduction of newer circuit designs and the corresponding demands placed on existing microreduction instrumentation are examined, with descriptions given of systems designed to overcome such problems. Advantages of pattern generation as a way to meet present photolithographic photomask production requirements are discussed. Other current techniques for photomask production are reviewed, along with a glimpse at some techniques now in the development stage.
An approach to a standard topology for digital hybrid integrated circuits. E. H. MAYER and G. M. NEMETZ. Proc. 21st Electronic Components Conf., Washington DC, USA, 10-12 May (1971), p. 538. Many of the new telephone systems under current development require large numbers of digital hybrid integrated circuits. The concept of a standard topology for the complex thin-film interconnection pattern is described. The construction of a multipin probe head is outlined. This head, when used in conjunction with the standard layout, permits complete low cost testing of the thinfilm carrier and enables multifault diagnosis of the circuit after bonding silicon integrated circuits. A general procedure for multiple fault detection and diagnosis is discussed.
Charge-coupled d e v i c e s - - a n e w approach to MIS d e v i c e structures. W. S. BOYLE and G. E. SMITH. IEEE Spectrum, July (1971), p. 18. Recent advances in materials and processing have resulted in a new class of information-handling structure--the charge-coupled device. This three-layer structure creates and stores minority carriers, or their absence, in potential wells near the surface of the semiconductor. The minority carriers move from under one electrode to a closely adjacent electrode on the same substrate when a more negative voltage is applied to the adjacent electrode. Because of their high transfer efficiency, these devices have already found application as image sensors. In addition, there is every expectation that memories made
WORLD
ABSTRACTS
ON MICROELECTRONICS
M O S technology isn't as complicated as it appears at first glance. Once the terms and technologies, "buzzwords" and processes are defined and placed in their proper perspective, the picture will start to clear.
5. M I C R O E L E C T R O N I C S
AND RELIABILITY
L i n e a r IC m a r k e t i n f e r m e n t . L. CURaAN. Electronics, 11 October (1971), p. 97. Reshuffle caused by recession and saturation of op amp sector pushes designers into consumer, computer interface, other special-purpose ICs.
DESIGN AND CONSTRUCTION
Production m e t h o d for a l u m i n u m b e a m leads on c e r a m i c substrates. R. E. MCMAHoN, F. J. BACHNER, R. A. COHEN, W. S. FRANKLIN and J. D. IMPEY. Proc. 21st Electronic Components Conf., Washington DC, USA, 10-12 May (1971), p. 96. A reproducible and reliable method has been developed for manufacturing aluminum beam leads on ceramic substrates. These beam leads are intended for ultrasonic bonding to the aluminum pads on commercially available integrated circuit chips. This developmental work has been aimed toward the production of a 30-stage T T L shift register in a beam leaded substrate configuration which is planar and eliminates the need for flying-wire bonds. The method employs the injection of water soluble silicates preloaded with aluminum oxide into preformed apertures in the substrate. When dried, these silicates have the strength and low vapor pressure necessary for the subsequent vacuum metallization and photolithographic operations. The silicates are contained in the substrate by a film of sheet photosensitive polymer applied over the entire surface of the substrate. After the silicates are dried, the photosensitive polymer is exposed and developed, leaving a film only over the silicate-filled apertures. The substrate is then metaUized with approximately 0.0005 in. of aluminum in a multifilament evaporator. At this point the silicates are removed by insertion of the substrate in deionized water and placing it in a cavitation mode using a commercial ultrasonic cleaner. The silicates are water soluble, and the presence of aluminum oxide particles helps to accelerate the cavitation process. After removing the silicates, the aluminum is photolithographically formed into the interconnection and beam-lead pattern, and the photo-resist and remaining sheet polymer removed. The prepared beams require no further processing and can be bonded directly to the chip bonding pads using an ultrasonic wire bonder modified with a flat bonding wedge. Bond strengths in excess of 10 g have been obtained and strengths are remarkably uniform.
Packaging t e c h n i q u e s for m o d e r n m i c r o e l e c trouics e q u i p m e n t . F. A. ROBm~TSON. Electronics Power, October (1971), p. 406. It is not easy for a designer to decide the form that electronic circuit packages should assume; this article explains packaging problems in the past, and presents a pattern of design for the future.
Buried w i r e m u l t i l a y e r c e r a m i c s . B. M. HARGIS. Solid State Technol., May (1971), p. 47. Multilayer structures are helping the microcircuit industry shorten electrical paths to reduce switching times. Ceramic packages and substrates with their hermetic and heat
transfer properties meet the design requirements of today's microcircuits. Design criteria and methods of producing these packages and substrates are described along with a discussion of refractory and noble metals used in the manufacturing process.
An o v e r v i e w of p h o t o m a s l d n g t e c h n o l o g y in the past d e c a d e . A. J. O'MALLEY. Solid State Technol., June (1971), p. 57. The development of the step and repeat microreduction photographic process for producing photomasks is described in the context of manufacturing requirements during the past ten years. The technical problems associated with the introduction of newer circuit designs and the corresponding demands placed on existing microreduction instrumentation are examined, with descriptions given of systems designed to overcome such problems. Advantages of pattern generation as a way to meet present photolithographic photomask production requirements are discussed. Other current techniques for photomask production are reviewed, along with a glimpse at some techniques now in the development stage.
An approach to a standard topology for digital hybrid integrated circuits. E. H. MAYER and G. M. NEMETZ. Proc. 21st Electronic Components Conf., Washington DC, USA, 10-12 May (1971), p. 538. Many of the new telephone systems under current development require large numbers of digital hybrid integrated circuits. The concept of a standard topology for the complex thin-film interconnection pattern is described. The construction of a multipin probe head is outlined. This head, when used in conjunction with the standard layout, permits complete low cost testing of the thinfilm carrier and enables multifault diagnosis of the circuit after bonding silicon integrated circuits. A general procedure for multiple fault detection and diagnosis is discussed.
Charge-coupled d e v i c e s - - a n e w approach to MIS d e v i c e structures. W. S. BOYLE and G. E. SMITH. IEEE Spectrum, July (1971), p. 18. Recent advances in materials and processing have resulted in a new class of information-handling structure--the charge-coupled device. This three-layer structure creates and stores minority carriers, or their absence, in potential wells near the surface of the semiconductor. The minority carriers move from under one electrode to a closely adjacent electrode on the same substrate when a more negative voltage is applied to the adjacent electrode. Because of their high transfer efficiency, these devices have already found application as image sensors. In addition, there is every expectation that memories made