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27 June 2017

New Model 365 UV Curing System

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by Don Moore - SEC President

New Model 365 UV Curing System

Introducing the Model 365 UV Curing System for Dicing and Back Grinding Tape

SEC will display the new Model 365 UV Curing system this year at Semicon West 2017 in San Francisco. The Model 365 features the same long light source life and simple operation as our popular Model 360. New features include much higher watt density (70 mW/cm2), most dicing tapes cured in about 5 seconds, touch screen display, self diagnostics detect LED failure. Larger cure area will expose adhesive on 300 mm frames for easy cleaning.

Standard features of the Model 365

10,000 hour LED life

Instant on, no warm-up

70mW/cm2watt density @ 365nM

Nitrogen purge capability

Touch screen display

Self diagnostics

Modular LED board design

No external ventilation needed

Works with all wafers & film frames up to 300 mm

27 June 2017

Semicon West - Live Demos!

Posted in Blog

by Don Moore - SEC President

SEC will do live demonstrations of Wafer Mounting, UV Tape, UV cure, and Die Picking in our booth 5958 at Semicon West 2017.

 

SEC will have a Model 3150 Wafer/Frame Tape Applicator loaded with Nitto DU300 UV Dicing Tape. We will mount a 200 mm wafer on a frame. We will not have dicing capability so we will cure the full wafer undiced on the New Model 365 UV Exposure System. Next we will remove the wafer from the tape on a Model 4800 Die Ejector Grid demonstrating the removal of die from tape without a pin poker.

21 June 2017

Semicon West

Posted in Blog

20 April 2017

Process to handle and bond a thin die

Posted in Blog

by Don Moore - President/SEC

Uniqarta, Inc. (www.uniqarta.com) has developed a process for flip-chip assembling ultra-thin (<50 µm) dies. This patent-pending process involves a material preparation step and a die placement step.

Uniqarta’s material preparation step involves thinning a commercial off-the-shelf device wafer to the desired thickness, bonding a support wafer (“handle wafer”) to the device wafer, and dicing the device/handle wafer combination to create individual die/handle stacks mounted on standard UV dicing tape. Each die/handle stack has a thickness comparable to a standard die and can therefore be handled and placed using standard die bonder equipment. Each die handle is flip-chip assembled by a die bonder onto a substrate. Since the handle is bonded to the die using a heat-sensitive adhesive, it is released during the die bonder’s thermal cure cycle when the die is bonded to the substrate. The handle is subsequently removed leaving behind only the ultra-thin die. a heat release adhesive.

 

 

In this example the thin die is 2.6 mm X 2.6 mm X 100 microns thick silicon attached to a 280 micron thick handle. Die as thin as 15-20 microns or less have been bonded using this method. . The dicing tape is Nitto DU300 UV tape. The die bonder is a Semiconductor Equipment Corp Model 860. The overall process is based on Uniqarta’s “FlexChipTM” technology.

 

The video shows the bonding process beginning with transfer stamping conductive adhesive from a manually doctored tray to the substrate. The bonder is equipped with a dual tool head. One tool is for transfer stamping. The second tool which is heated is for bonding the die. The 860 automatically brings the appropriate tool into position. After stamping conductive adhesive onto the substrate the die stack is aligned and lowered to a specific bond load.

Once the die stack is at bond load the epoxy will be cured and the temporary bond will be released. The bond tool is slowly retracted taking the handle away for disposal and leaving the bonded die on the substrate. All bonder settings including sequence, cycle time, bond load, temperatures and tool velocity are defined in the Model 860 macro program. The images in the video were captured by the optional 860 side view camera.

The demonstrated process shows a method by which SEC’s die bonder can be used to place and adhesively bond ultra-thin die using Uniqarta’s FlexChip process.

 

The SEC Model 860 Die bonder used in this application was equipped with the following options:

·         High resolution dual imager vision system

·         Dual tool

·         Manual dipping station

·         2” rapid heatstage

·         Dual goniometer stage leveling

·         Side view camera

·         Table

27 March 2017

A Google Company Becomes an Interesting Dicing Tape Customer for SEC

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by Suzy Tritenbach - SEC's Dicing Tape Specialist

A Google Company Becomes an Interesting Dicing Tape Customer for SEC

Google recently exited the self driving vehicle business and spun off a new company to continue the effort. Waymo opened for business in December of ’16 with a new approach. Google’s goal was to build a vehicle, sensor system, and software. Waymo has decided to focus on the sensor system and software. They are working with established companies to get the vehicle.

Lidar (light detection and radar) is one of the principle sensor systems used to guide self driving cars. The Waymo system includes three Lidar systems. One of these systems can cost as much as $75,000. The high cost is one thing that has been a barrier to commercializing self driving cars. Waymo has decided to bring the manufacturing of Lidar systems in House to reduce cost and improve reliability.

One step toward manufacturing their own LIDAR is to manufacture their own sensors. Light detection sensors generally are manufactured in wafer form on silicon. Part of the packaging process is to dice the wafers and for that step Waymo is using SEC dicing tape.

A fast moving company like Waymo depends on short lead times and dependable service to meet their goals. SEC delivers many items from stock in one week. Our Nitto Dicing tape has been an industry standard for more than 40 years.

Waymo has successfully reduced the cost of Lidar. Latest information is that the Lidar Team at Waymo has reduced the cost by 90%.

29 March 2017

Medium Tack Blue Tape in Outer Space?

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Medium Tack Blue Tape in Outer Space?

Deep Space Systems in Littleton, Colorado is a subcontractor on the Orion multipurpose crew vehicle. Lockheed Martin is the prime contractor for NASA on the Orion Project.

What’s interesting about the Orion project is it will support travel to the International Space Station, the Moon, and Mars. It can also go anywhere that can be reached in 1,000 days. Of course they will probably want to go 500 days or less each way so they can make it back.

The Orion looks a lot like the old Apollo systems but it is tremendously advanced compared to the Apollo and the Shuttle. Deep Space Systems provides engineering services and in the application we are familiar with they provide machined parts. As you can imagine, parts for a space crew vehicle need to be kept in pristine shape, so Deep Space Systems applies “Blue Tape” to protect the parts. Blue Tape is also known as “Dicing Tape” in the Semiconductor Industry.

They have chosen SEC Blue Medium Tack tape because it has properties that are ideal for surface protection. These are the same properties that make it ideal for wafer dicing. The adhesion is strong enough to adhere during shipping and handling of machined parts and light enough to be easily removable. This compares to strong enough adhesion for dicing and light enough adhesion for die picking. 

01 February 2017

SEC Model "450 Hot Shot" Rework Station

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We still make the Model 450 Hot Shot Gas Rework Station. The Model 450 is uniquely qualified for rework of hybrid devices. It was originally developed to solve a problem with the manufacture of LED watches. There was a yield problem with several die in the early versions so a method was needed to remove and replace the die. The Model 4400 was developed.

The Model 4400 used a tubular quartz nozzle with a serpentine wire heater element. The nozzle typically had a 0.060" opening. There was a heated stage with vacuum to hold the substrate. A die pusher and microscope were optional. The unique capability was that the nozzle could heat a die hot enough to break down the epoxy without overheating the nearby die. The die pusher would apply force to the side of the die until it popped free. The die pusher doubled as a scraper to clean the bond site for attachment of a new die.

Sometime in the 80's the Model 4400 was redesigned for better control of the stage and gas temperatures. The nozzles were also redesigned to be interchangeable. Various shapes and sizes of nozzles became available as die sizes grew and SMT became popular. The redesigned 4400 became the 4450 and eventually the Model 450.

There are still applications which the 450 is uniquely qualified for such as implanted medical devices and high rel hybrid circuits. Complicated hybrid circuits are more likely to need rework as the complexity increases and the volume of production decreases. In many cases the die are attached to a ceramic substrate with epoxy and wire bonded. The rework process cannot be done by most SMT rework systems on the market.

The main issue is that the die are small and very close to other components. The substrate also must not be overheated or heated unevenly which will cause stress. Most SMT systems on the market blow a lot of hot air which over heats other components. Their work holders are designed for circuit boards and they don't have a convenient way to push the die off without causing other damage.

The Model 450 solves all of these problems. The hot gas (Nitrogen) is heated to a fairly high temperature, normally about 500 C. The volume of gas is controlled to a low flow rate of about 5-10 SCFH. The nozzle is selected to be slightly larger than the die for optimal performance, however this is not critical. The stage temperature is set to be well below the maximum temperature for the assembled substrate, but high enough to avoid stress in the substrate caused by spot heating. Typical stage temperature is about 125 C.

To remove a die the operator places the substrate on the stage against the backstop and turns on the vacuum. The die is centered under the nozzle. The operator has manual Z motion position control of the nozzle. The side die pusher is aligned almost touching the die. The gas flow and vacuum to hold the stage are started by the button on the stage or the foot pedal. The die side pusher is adjusted to apply some pressure against the die. When the heat has broken down the epoxy the die will break free. The whole cycle takes about a minute. The 450 can also be used to remove and replaced soldered SMT components.