CN102034705B - Processing technology for reducing large-current diode stress - Google Patents

Abstract

The invention discloses processing technology for reducing large-current diode stress. The processing technology comprises the following steps of: leading, and annealing a copper lead; soldering, and filling a chip; welding; molding; and performing sectional curing. The structural stress of a product is reduced by adding a step of annealing the copper lead and changing the conventional curing mode into the sectional curing mode on the basis of the conventional process, so that the advantages of the conventional technology are overcome and the effect of improving the reliability of the product is achieved.

Description

A kind of big electric current diode stress reduces processing technology

Technical field

The present invention relates to a kind of processing technology of electronic device, the processing technology that particularly a kind of big electric current diode stress reduces.

Background technology

At present big electric current diode is the directly welding of electrode filling back with the copper lead-in wire mainly in process of production; The technology of directly solidifying after the moulding; Its shortcoming is: this welding procedure can cause chip surface to receive big stress and produce damage, and forming and hardening technology makes bigger stress such as the interlinkage reaction of epoxy resin is quickened, epoxy particles can produce extruding to chip and causes chip damage etc.

Summary of the invention

To the problems referred to above, the invention discloses a kind of diode of processing is the technology that reduces welding stress and slow down the forming and hardening Stress Release, and this technology is carried out as follows:

A. copper lead-in wire being packed in the graphite boat through machine, is that electrode is packed into behind the graphite boat at the copper lead-in wire, under the protection of hydrogen, nitrogen mixture, carries out high annealing, and the time was greater than 10 minutes more than 300 ℃;

B. will anneal and natural cooling after graphite boat on load scolder and chip respectively;

C. a graphite boat that does not load scolder, chip is turned over the turnback location and be combined on the graphite boat that scolder, chip are housed, advance continuous tunnel furnace then and carry out welding;

D. will weld good product utilization mould and press and be coated to epoxy resin the die sites that has of welding product;

E. segmentation is solidified, and slowly is warming up to 80 ℃ through 30 minutes at first at normal temperatures, and under 80 ℃ situation, keeps baking 2 hours, then under 80 ℃ of situation, slowly is warming up to 110 ℃ through 30 minutes, and keeps baking 2 hours; Under 110 ℃ of situation, slowly be warming up to 170 ℃ at last, and keep baking 6 hours through 30 minutes.

The present invention has reduced the structural stress of product, thereby has overcome the defective of present technology through the process modification to two operations in the diode course of processing, reaches the effect that promotes the product reliability ability.

Embodiment

Below in conjunction with embodiment the present invention is done more detailed description.

A kind of big electric current diode stress reduces processing technology, and this process implementing step is following:

Ejectment is packed copper lead-in wire in the graphite boat into through machine;

Copper lead-in wire annealing, the graphite boat of the copper of will packing into lead-in wire put into be connected with hydrogen, nitrogen hybrid protection gas the continuous tunnel furnace sintering once, self stress of copper lead-in wire is reduced;

Scolder, chip filling are with loading scolder and chip respectively on the graphite boat behind annealing and the natural cooling;

Advance the continuous tunnel furnace welding; Be a graphite boat that does not load scolder, chip to be turned over the turnback location be combined on the graphite boat that scolder, chip are housed; Laggard continuous tunnel furnace is carried out welding, and advancing the continuous tunnel furnace mode is that two rows are placed on the enterprising continuous tunnel furnace of continuous tunnel furnace chain side by side;

Moulding, product utilization mould and press that welding is good are coated to the position that chip is arranged of welding product to epoxy resin, play the performance of protection chip and the anti-mechanical stress of enhancing product;

Segmentation is solidified, and carries out the back after the formed product and solidifies, and curing mode was directly toasted 6 hours under 170 ℃ of situation by former, changes three sections bakings into, that is: first section: slowly be warming up to 80 ℃ through 30 minutes under the normal temperature, and under 80 ℃ situation, keep baking 2 hours; Second section: under 80 ℃ of situation, slowly be warming up to 110 ℃, and keep baking 2 hours through 30 minutes; The 3rd section: under 110 ℃ of situation, slowly be warming up to 170 ℃, and keep baking 6 hours through 30 minutes.Carry out segmentation and solidify,, reduce the damage that particle causes chip in the epoxy resin to slow down the interlinkage reaction speed of epoxy resin.

The present invention has passed through the process modification of two operations, reduces the structural stress of product, to reach the purpose that promotes the product reliability ability.

Through the site operation personnel is carried out training on operation, and, form the training program plan and carry out periodic Ongoing Training action, so that operator's hints on operation on top of through practical operation rehearsal evaluation personnel technical ability.Then to former technology and experiment of the present invention contrast:

Test products model: with 6A10 model arrangement diode test explanation

Former technology: welding: directly carry out chip filling welding after the ejectment; Solidify: directly carry out 170 ℃, 6 hours baking after the moulding.

Improve back technology: welding: through continuous tunnel furnace annealing, load welding then after the lead-in wire ejectment; Segmentation is solidified: the segmentation of carrying out 80 ℃/110 ℃/170 ℃ three temperature sections after the moulding is respectively solidified.

The final products testing performance index:

Claims (1)

1. one kind big electric current diode stress reduces processing technology, and it is characterized in that: this technology is carried out as follows:

A. copper lead-in wire is packed in the graphite boat through machine, after the copper lead-in wire is packed graphite boat into, under the protection of hydrogen, nitrogen mixture, carry out high annealing, the time was greater than 10 minutes more than 300 ℃;

B. will anneal and natural cooling after graphite boat on load scolder and chip respectively;

C. a graphite boat that does not load scolder, chip is turned over the turnback location and be combined on the graphite boat that scolder, chip are housed, advance continuous tunnel furnace then and carry out welding;

D. will weld good product utilization mould and press and be coated to epoxy resin the die sites that has of welding product;

E. segmentation is solidified, and slowly is warming up to 80 ℃ through 30 minutes at first at normal temperatures, and under 80 ℃ situation, keeps baking 2 hours, then under 80 ℃ of situation, slowly is warming up to 110 ℃ through 30 minutes, and keeps baking 2 hours; Under 110 ℃ of situation, slowly be warming up to 170 ℃ at last, and keep baking 6 hours through 30 minutes.