ENTROPY LTD LLC

 LTD LLC

From Disorder Comes Order                                                    .

Entropy LTD LLC (formally Mountain Research) is located in Pine Grove California  and has been in business since 1993 providesTechnical consulting services in Materials and Process Engineering for  manufacturers in the Optics, Laser, X ray Tube, Semi Conductor and Bio Technology Industries.

       "You can't control what you can't measure" - Entropy LTD

Entropy LTD LLC provides:

• ULTRA HIGH VACUUM SYSTEM DESIGN including New Viscous Flow Processing
  
• Process and materials engineering
• surface and bulk chemical analysis,
• debrazing, brazing
• component chemical cleaning to UHV (Ultra High Vacuum) requirements, 

1. Proven Expertise in micro contamination control, ultra clean processing of materials, optics testing and materials analysis. Using SEM , AFM, TOF SIMS, RBS, FTIR, MS, GC. Below is an FTIR spectra before and after chemical cleaning by ENTROPY LTD LLC. This and similar methods are employed to establish the correct cleaning process and to VERIFY its effectiveness,

2. Yield enhancements and Warranty Reduction,  process improvements  for increasing product performance, lifetime , reducing warranty and improving yields. ENTROPY LTD LLC has a proven track record of quickly resolving difficult process issues. A customer had to replace nearly 50 % of product, in one of its product lines, due to lifetime issues.

     ENTROPY LTD LLC was able to determine the exact failure mechanism,  make specific changes to the polymeric sealing material for the devices optical and vacuum seal. Further adjustments to its mechanical and vacuum properties via reformulation resulted in substantive positive changes in performance and reliability. Initially increasing lifetime from 3-5 months to over nearly 2 years.  Final adjustments increased this to beyond warranty values.   

    Limitations from device construction and design imposed performance constraints ultimately creating product holds.  Systematic evaluation of conversion efficiency as a function of pressure and of residual moisture initiated a total redesign of vacuum processing methodology to exploit the advantages of processing in the low vacuum, viscous flow region. This Process station design increased yields and energy 15%.

     Here polymeric seals impose limits on ultimate package temperature used during vacuum processing. Here temperatures could not exceed 120 C. The use of viscous flow processing enabled higher internal temperatures with lower package temperatures that never exceeded 110 C during processing. 

    This technique is not constrained to conductance limitations from small tubing typically used for smaller devices. Ultimately residual contamination was reduced nearly 100 x relative to levels achieved by standard ultra high vacuum processing methods.

     Viscous flow is ideal for packages, devices that have small dimensions and utilize polymeric or elastomeric seals. Perfect for electro optical packages/devices.

3. Design of special testing platforms for optics/materials evaluation  assessment (below FLIR based Laser Optics Absorption Station) glow discharge, photometric detection of leaks or  gas  analysis for vacuum devices, processing. RIGHT IMAGE: False color photometric  image of fused coupler torch showing distributions of H beta emission 488 nm), H alpha (656 nm)  Emission and OIII emission (500.7 nm).  Used to determine optimal mixture of Hydrogen Oxygen Mixture and optimal positioning of coupler for improved yields, performance of fusion process - from 54 % to above 84 %.

4. UHV system Design- Entropy LTD has designed over 20 vacuum process stations, leak checking stations and vacuum enclosures for a number of customers. Many of them operate at mid to low 10 E-10 scale vacuum. Expertise in Leak check and process control procedures, vacuum brazing, inert gas brazing and low pressure systems. Vacuum processes incorporating glow discharges, flow through, UHTLPG  Ultra High Temp Low Pressure Gas to obtain very low residual contamination levels. Combined with Mass Spectrometer expertise for analyzing gases.  We can also provide  spectroscopic , narrow band photometry emission gas analysis assuring greater accuracy due to reducing the distance from detector and sample. 

Ask about stand alone PIC micro controlled system controls available for both using 16f84 PIC and solid state relays.This is a very basic design and provides remedial control for simple functions such as pump down and fail safe - for value closure during power failure. Also to assist with setting proper cross over pressures. . 

5.  Viscous Flow Technology (derived from simple gas flow dynamics)  provides for lower device bake out temperatures. many times less than the T max for polymeric sealing materials).

For temperature sensitive materials requiring vacuum processing. This process can typically reduce  volatile residuals to less than those of  standard UHV processing within same process times.

This technique has long been known as an alternative and more effective process when smaller devices are used with polymeric seals and smaller (low conductance) pump outs.

The other advantage is smaller diameter (lower conductance) tubing can be used for pumping out the device.

This would mean from 5 % for UHV process to less than 100 ppm for Viscous Flow processing.

 This process can be used for devices with temperature sensitive seals or materials sensitive to  oxidation.  Lower temperatures (required by elastomeric seals, polymer seals) using less time to achieve significantly lower residuals as compared to standard UHV processes. 

Below is an example of a full scale industrial system for processing up to 30 devices at once.

6. Process Engineering:  When your company has a yield or warranty issue that has eluded resolution despite teams and consultants. Entropy LTD can provide expertise in the area of improving  product performance , lifetime, warranty and yields.

There is a clear advantage in having experience in multiple areas when trying to find solutions to manufacturing issues. Experience in optics, materials, chemistry and various aspects of engineering (mechanical, packaging, manufacturing) become useful and provide for a more cost effective approach.

While I cannot guarantee finding a solution; ENTROPY LTD has a very high rate of success over its 16 years in business. 

Clients:

Spectra Physics, Laserscope, Molecular Dynamics,ILC Technologies, INTA Advanced Ceramics, Conductus, Astec Semi conductor, Trumpf Photonics, Newport, De Le Rue Giorri, Evergreen Lasers, Zygo.Oxford X Ray Group.

 Below is Dynamic SIMS showing distribution of various elements in coating.  This kind of information is important for evaluating coatings of any kind. In some cases establishing stoichiometry is vital for verification of process. 

A Laser Company:

Unstable high power lasers:  examination of the interface layer between di electric layers using TOF SIMS (a powerful, highly sensitive way to measure the chemical composition on a surface) showed measurable counts of organics and Alkali metals. 

A review of the cleaning process revealed information that the origin of these peaks were consistent with improper cleaning of the optical surface prior to over coating.

Modification of the cleaning process eliminated the problem. Absorption from this layer of residue was sufficient to cause localized heating of the optic; changing its refractive index. 

Although a multitude of scans using SIMS and analysis of these optics had been done over the course of many years; there was never an advancement to a solution. The solution was found when TOF (Time Of Flight) SIMS (Secondary Ionized Mass Spectroscopy) was used rather than SIMS.

TOF SIMS differed in that it could discern whether a specific peak originated from an organic or inorganic   From these findings it was determined that  detergent residue was responsible for the observed increase in absorption from inadequate rinsing.

The above examples illustrate the significance of using the appropriate analytical technique in combination with experienced engineering and process review to find solutions to existing problems.

A semi conductor company:

       $500,000 Power worth of supply chips remained high after routine mil spec testing.

        Here compilation of many variables was necessary to solve this puzzle.  Electronic testing showed capacitance behavior before testing and resistive afterwards. Review of the schematic along with analysis of the depth of resistor implantation provided a framework for a working theory.  Subsequent chemical analysis of the surface showed highly moblie ions causing implanted resistor values to change.

        Again, improper chemical cleaning of the materials used to manufacture this IC chip. Review of the process, chemical analysis, experiments and materials investigation resulted in finding a worable solution. In this case a simple modification of the process allowed many of the IC's to be used saving the company more than half of the original $500,000 that was thought irretrivable.

 A BIO MEDICAL Laboratory:

       A quantitative DNA fluorescence assay was hampered from a high background from residual hydrocarbon on the fused silica fibers used to conduct the test.

      Here once the hydrocarbon was identified as polyimide, a high temp , highly durable polymer. Efforts to find alternative methods to chemically remove this polymer from the glass were begun.

      Two new methods were discovered enablng the manufacturer to assay DNA with a 1000 fold reduction in background.

A Laser Company:

      Processing of a laser using standard ultra high vacuum (UHV) techniques left large (5%) moisture in the ceramic laser housing.  Since epoxy seals were used temperatures greater than 100 C were not feasible. Development of a higher temperature seal was not within the budget.

      Here the use of a novel approach to vacuum processing was required. Viscous flow processing  highly effective method to reduce residual volatile contaminants resulting in from 10 to better than 100 x reduction of volatile contamination as compared to standard UHV method.  Contact us for your application.

        We also have expertise in developing polymeric seals for specific applications such as for the reduction of permeation rates below those attained by ceramic formulations.

. In some cases reactive gases such as oxygen,CO and CO2 can be reduced by these special formulations. We use materials ranging  from microns to nanometers in size to take advantage of their ability to alter the polymers mechanical and hermetic properties to the clients specifications. 

 Contact us if you have an application requiring specific hermeticity/permeation requirements.

       These few examples of our success should help you to understand what we can do and our versatility in finding solutions.  Other work involved: UHV system design, chemical cleaning systems, improvements to diode lasers, materials investigation of NLO (non linear optical) materials.  With real world engineering experience coupled with chemistry and material science ENTROPY LTD LLC is a recognized leader in finding simple solutions for your manufacturing problems

        Other examples: Simple in line process measure to prevent improper filling of argon ion lasers, process improvements to a brazing operation increasing yields from 40 % to 95 %, improvement in optical sealing method resulting in reduction of warranty exposure from 40 % to less than 3 % in less than 3 months. Coating chambers left unused due to metal film quality issues; re certified for operation within 30 days. DNA Fluorescence assay signal to noise improved over 1000x by the development of a chemical stripping formulation for polyimide. Fused coupler process yields increased from 30 % intermittently to over 85 % first pass implementation. Optical device lifetime increased 8-10 x by reformulating the sealant and optimizing its application.  Optical absorption measurement system designed enabling RT multi functional measure of optics (scatter, reflectivity, substrate and thin film absorption measurement, substrate fluorescence and thin film thermal conductivity, UV damage susceptibility and mode distortion).

       Contact us for your application. 

What We Do

      Entropy LTD LLC offers a range of services from process consulting to materials investigations to chemical analysis (using outside services)  with vacuum processing, vacuum system design, failure analysis, yield improvements, warranty reduction, process trouble shooting, clean line development, leak detection, vacuum and gas seal development, UHV system design, Chemical cleaning and Viscous Flow Processing.Hermetic packaging

technical consultant and chemist, optics cleaning , optical damage, process control, vacuum awareness and micro contamination control, process engineering, presentations in RGA, Gas analysis, materials handling and vacuum component cleaning

Contact: Philip Young

email:pcyoung@entropyltd.net

entropyltd@att.net

call 209 296 2276