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Learn about the history, challenges, and improvements in double-sided bonding using the Kulicke & Soffa 8090 machine. Explore the development of bonding jigs, handling frames, and bond quality control techniques.
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Front-end Bonding Kulicke & Soffa 8090 Version Mark Whitley (mwhitley@liv.ac.uk)
History • 28 March: Beginning of double sided bonding using K-04's on KS8090. • 7 April: First double sided bonding succeeded. • During the summer we ran into more problems with the machine. This time the machine was not operational for several weeks due to the unavailability of service engineers and also because of the large number of parts that had to be shipped to us. • 20 June: 8090 had software programming problem which could be overcome. K&S had been alerted to the problem. • 21 June The handling jig had been finalized . This now allowed the K-05 bond jig and the laser system to be completed. • Late June: 8090 Repaired and operational. Mark Whitley (mwhitley@liv.ac.uk)
History • 22 June: Design of integration of handling jig with double sided bonding jig complete. • 25 June: Handling Frame Built. Bonding results on 710 excellent on double sided jig. Bonds approx 7g strength. • 26 July: Bonding jig bases started being manufactured. • 17 August: Back ends of the K-05 programmed. Bonding jigs (including laser cooling) finished. • 9 Sept: We believe a version of the double sided bonded jig can be used. • 22 Sept: K&S inform us they CANNOT provide a maintenance contract in the UK for the 8090. This is a problem. • 23 Sept: Leak in vacuum system for 8090 cured. • 13 Oct: Independent service contract for bonders bought by Liverpool University. Mark Whitley (mwhitley@liv.ac.uk)
History • 21 Oct: Bonding learning improved by minor modification to bonding jigs - small clamps were inserted. • 31 Oct: Programming of 8090 now complete - but calibration on final hybrids may need redoing. • 2 Nov: 8090 Sensor failure. Contacting K&S for replacement parts. A fix was found for today. Spares on order. • 4 Nov: 8090 Repaired. • 16 Nov: 1st mechanical module being bonded. Evidence of additional "bounce" in bonding jigs. This lead to 3% of bad bond on the last iteration. This is being improved. • 29 Nov: modifying the wire-bonding jigs to make a better vacuum seal around the pitch adaptors. Mark Whitley (mwhitley@liv.ac.uk)
Current issues February 2006: Much time has been spent programming for the front end, but yet again the 8090 machine has let us down. This time by producing inconsistent bond foot formation, there by taking away confidence that wires are going to be adhering to the substrate and with the correct looping properties. We called out our independent UK based engineer who was unable to correct the fault, so now we have to wait for the Kulicke and Soffa engineer to assist us. He is due early March so we have activated our contingence plan which is to write new programmes for the front end bonding, using our Hesse and Knipps bondjet 710. We have two of these, with proven track records, having completed over one million bonds on the atlas programme. We had to get some special wedges made to allow the machine to bond to our very fine pitch and pad formation, as well as carrying out wire pull strength tests. All this work has now been carried out and we have produced our first electrical modules. Mark Whitley (mwhitley@liv.ac.uk)
First Generation of Double Sided Bonding Jig Mark Whitley (mwhitley@liv.ac.uk)
Aluminium Handling frame Designed for Double Sided Modules Mark Whitley (mwhitley@liv.ac.uk)
Plastic Handling Frame Designed Double Sided Use Mark Whitley (mwhitley@liv.ac.uk)
Second Generation Bonding Jig Now Capable of Accepting The Handling Frame Mark Whitley (mwhitley@liv.ac.uk)
Reference System Layout for Chip to Pitch Adaptor Mark Whitley (mwhitley@liv.ac.uk)
Reference systems Layout for Detector to Pitch Adaptor Mark Whitley (mwhitley@liv.ac.uk)
This picture shows bonds from the chip to pitch adaptor Mark Whitley (mwhitley@liv.ac.uk)
Closer look at chip to pitch adaptor bonds Mark Whitley (mwhitley@liv.ac.uk)
This Picture Shows Bonds from the Radial Detector to the pitch Adaptor Mark Whitley (mwhitley@liv.ac.uk)
This Picture Shows Bonds from the Phi Detector to the pitch Adaptor Mark Whitley (mwhitley@liv.ac.uk)
Double Sided Module On The Kulicke & Soffa 8090 Bonding Machine Mark Whitley (mwhitley@liv.ac.uk)
Quality control During the running of the bonding programme we constantly monitor for correct loop formation and look for any missed wires. After each run of wires is complete we visually check for any defective wires, then carry out repair work. This is all logged into the data base. Mark Whitley (mwhitley@liv.ac.uk)
Quality control Wire pull testing using our Dage series 4000 Mark Whitley (mwhitley@liv.ac.uk)
Quality control • This machine uses a very small hook to pull the wire, this tests how many grams of force it takes to break the wire. Mark Whitley (mwhitley@liv.ac.uk)
Quality control • When pulling wires we hope to achieve at least a mean of seven grams of force. Mark Whitley (mwhitley@liv.ac.uk)
Quality control • We can monitor the history of all tests carried out within a batch. Mark Whitley (mwhitley@liv.ac.uk)
Quality control We also compare the grade pareto, which is the way in which the wire failed. Mark Whitley (mwhitley@liv.ac.uk)
Quality control Proposals for extra quality control • Introduce a standard test board for bond testing. This would involve using an independent substrate, such as Cicorel board, which is a known good and repeatable material for bonding onto. We would carry out a series of bonds then pull test them. • Test the practicality of non destructive testing. This is where we can set a limit to which the pull tester will pull a wire, so we would set a minimum level that a wire can fail at ie 4 grams and the machine will pull to this limit and hold for a set period of time if desired. If the wire breaks then we would have to carry out further investigations. Mark Whitley (mwhitley@liv.ac.uk)