Kelvin Probes and Work Function Difference

Kelvin probe techniques are used to measure the work functions of materials. These techniques are applied successfully in surface science under UHV conditions. For example, if you want to study the adsorption of molecular or reconstruction processes of single-crystal surfaces, that will cause a change in surface or dipole potential. Recently, Kelvin probes have been applied to corrosion science and found to be highly successful. This probe is named after Lord Kelvin.

What is Kelvin Probe?

The Kelvin Probes are a non-contact and non-destructive calculative device used to investigate the properties of the materials. Here, the probe is based on the vibrating capacitor and calculates the work function difference. In the case of non-metals, it is surface potential and in between a conducting specimen & vibrating tip. The work function is a sensitive indicator of surface condition and is affected by the following:

·         Absorbed layers

·         Surface Reconstruction

·         Surface Charging

·         Oxide Layer Imperfections

·         Surface & bulk contamination

What is Kelvin probe force microscopy (KPFM)?

KPFM or Kelvin probe force microscopy is known as surface potential microscopy and it is also a non-contact type of atomic force microscopy (AFM). These techniques are mainly used for measuring corrosion and coatings. The work function of the surfaces is measured either in atomic or molecular scales. The work function is related to the following surface phenomena:

·         Catalytic Activity

·         Reconstruction of surfaces

·         Doping and band-bending of semi-conductors

·         Charge tapping & Corrosion

The work function map generated by KPFM provides information about the composition and electronic local structures on the surface of a solid. Equip Test provides Kelvin Test Probes with following features:

1.       4 wire measurement

2.       Industrial solution

3.       Easy integration

As the Kelvin probes (KP) techniques find the Contact Potential Difference (CPD) between two surfaces that are in close proximity. In the 1st case, there will be two metals, but there is no electrical connection between them. In the second case, as the two metal pieces are connected by an electrical wire, here the electrons with a smaller work function will travel to the metal with a larger work function. As a result that, the metal with a smaller work function is to be charged with positive whereas others would be charged negatively. This will create electric potential between the two metals as their electronic state is changed relative to each other.

IPTE- IN - LINE FIXTURE

 

IPTE-Integrated Production and Test Engineering is one of the leading suppliers of automated production equipment in the world for the electronics and mechanical industry. In-Circuit or functional test and programming processes are automated with Easy-Test-Handler (ETH) of IPTE. The ETH is used for single-circuit boards, multiple boards, or the carriers for circuit boards. Test fixtures get set up for three different ways:

·         In-line: This test fixture produces test fixtures in the same process as that of the rest of the test. An in-line setup is the simplest test fixture to be manufactured. It goes to duplication if multiple tests need the same initial data.

·         Delegate: This setup puts the test fixture in a separate standalone helper method that can be accessed by multiple test methods.

·         Implicit: This setup puts the test fixture in the setup method that is used for setting up multiple test methods.

The IPTE Easy-Test-Handler (ETH) is a cost-effective test solution with a solid footprint. It is integrated into a fully automated compatible test environment-SMEMA and is prepared for Industry 4.0 solutions. Easy-Test-Handler (ETH) offers adequate space for 19-inch test equipment (10 HE). An integrated LC touch display will provide accessibility to all settings and parameters.

 

The IPTE Factory Automation manufactures standard machinery & turnkey automation systems for the production, testing, and treatment of printed circuit boards and final assembling. This equipment is used for the industries such as automotive, consumer electronics, telecommunications, and other types of the electronics industry. But the principal focus is on the automotive industry. The cars that are produced in Europe contain the parts built with IPTE equipment.

Equip Test provides following INLINE SPEA 3030 FOR IPTE HANDLER:

·         ILFS-2A-SPEA3030-BOT44x72-D

·         ILFS-SPEA-3030

·         ILFS-2A-SPEA-3030

And INLINE SPEA 3030 - 190 FOR IPTE HANDLER-ILFS-2A-SPEA-3030-190

The IPTE Test-Handlers is mostly used around the world. Because of its performance IPTE Test-Handlers, it is regarded as a high handling speed of the test head and it takes less than 4 seconds for PCB exchange.

Cable Harness Test Systems and Test Fixtures

 

The cable harness is also known as a wire harness, cable assembly, or wiring assembly. They are best described as a string of wires or cables used for operating currents or transmitting informational signals. These wires are bound together with electrical tape or clamps. Cable harnesses are designed for geometric & electrical requirements. As there is a growing demand for the error-free production of cable harnesses, there is also an increasing need for cable harness test systems and modules.  Once this test process was a slow and manual point-to-point operation, now it has been transferred to a sophisticated, efficient, and computerized aided process.

Test Fixturing

The test fixturing has been taken over by cable harness industry. These testing systems have two benefits:

·         Ease of use for the operator

·         Lesser maintenance

Harness manufacturers generally use mating connectors for testing. There are two forms of cable harness test-

·         First build the harness offline and bring it to wire harness test station. 

·         The other type is to test simultaneously while building.

When a cable harness is produced, it would be subjected to various tests to check its quality and functionality. The test board is used to measure the cable harness’s electrical capabilities. It can be achieved via the input data of a circuit where more than one cable harnesses are programmed into the test board. The harness is measured according to its ability to function in a simulated circuit.

Hipot Testing and 4 Wire Kelvin Testing

Delrin and polyurethane provide excellent dielectric qualities for the manufacturing of Hipot & Kelvin test fixtures.  These tests are operated at high voltage and need special attention as it provides insulation between the spring probes. It prevents arcing and fake failures. It is necessary to keep the fixtures free of debris as this debris can be the cause of false failures. The basic continuity test fixture is easily modified to perform a 4 wire Kelvin test.

 

 

Functional Testing

Spring probe test fixtures are mostly used for automotive and other applications because of their durability & serviceability. This is particularly effective when thousands of tests are done. These test fixtures are typically designed for hand-held and incorporate robust strain reliefs. Equip test offers a range of test probe systems and modules.

Agilent 3070 In-Circuit Test (ICT) System

 

The Agilent 3070 In-Circuit Test (ICT) System is a flexible test worldwide. Its 4 key attributes include- Agile test technology, Constant technology breakthroughs, Profit-enhancing business services, and its adoption makes it a perfect fit for electronics manufacturing. It provides exceptional flexibility, freedom, and agility required to thrive in a chaotic world.

What is ICT 3070?

Agilent / Keysight ICT 3070 are Industry's Most Advanced and Flexible In-Circuit Test System. It is highly complex and high speed Printed Circuit Board Assemblies.

What does ICT test?

The In-circuit test (ICT) is a white box testing. It is a process where an electrical probe tests the following:

1.       A populated printed circuit board (PCB)

2.       Checking for shorts

3.       Opens

4.       Resistance

5.       Capacitance and other basic similar quantities will show if the assembly is correctly fabricated or not.

In-system programming is a critical feature in programmable logic devices (PLDs) that integrates PLD programming into board-level testing. The benefits it provides include:

·         Reduced inventory of pre-programmed devices

·         Low cost

·         Fewer devices damaged during handling

·         Increased flexibility in engineering changes

The software and device support integrate in-system programmability (ISP) in the existing test flow for the Agilent 3070 system.

In-circuit testing will cause mechanical failures like capacitor flex cracking and pad cratering. It happens on a bed of nails tester if there is the presence of excessive board flexure or high probe forces. It is always challenging to optimize for ideal support locations & probe forces instead of spending resources on designing and building an ICT fixture

What is Agilent 3070?

You can say it Acculogic Services or In-Circuit Test Programming Services or Keysight (Agilent) 3070 Test Program Development Services. It offers turn-key test program development & fixture fabrication services to the Keysight (Agilent) 3070 family of In-Circuit Testers.

 

Equip test provides turnkey test program development and fixture fabrication for the Keysight Agilent 3070 In-Circuit Testers. As the company has a team of highly experienced and trained test engineers, it provides In-Circuit test programs with the highest fault coverage & fast cycle time. Here, we offer the following range of Agilent 3070 In-Circuit Testers:

·         KEYSIGHT - AGILENT - HP 3070-VFS-E90-2ST-HP3070-VC09

·         KEYSIGHT - AGILENT - HP 3070-VFS-E90-HP3070

·         KEYSIGHT - AGILENT - HP 3070 DOUBLE - BANK-VFS-E92-HP 3070

·         KEYSIGHT - AGILENT - HP 3070-VFT-E91-HP3070