Chemistry and Surface Analysis

FT-IR (Fourier Transform Infra-Red Spectroscopy)

FT-IR provides structural information about the analysed material thanks to the interaction of an infra-red radiation with the material. It is suitable for the qualitative and quantitative analysis of organic compounds, identifying the functional groups inside the molecules; characterisation is performed by comparing the spectra with databases or by attributing every resulting peak to the vibration of a specific functional group.

A limit of the instrument is that, for natural organic substances, it allows only the distinction of compound classes and not of the single substances (for example, it identifies whether a substance belongs to the oil category, but not which specific substance it is).

TIC – Total Ionic Contamination

The ionic cleanliness test measures the conductivity/resistivity of a solution obtained by sample treatment. The measurement can be related to the quantity of ionic material present; the resistivity decreases as the ionic contamination level increases. Ionic contaminants are usually flux residues or harmful materials from the production process, and they can downgrade the reliability of electronic components and assemblies by contributing to leakage current, easing dendritic growth and increasing corrosion risk.

IC – Ion Chromatography

Ion Chromatography (IC) is an analytical technique which separates ions and polar molecules according to their charge. Each species interacts differently with the stationary phase (a column full of resin) and has a different retention time, which allows them to be quantified individually after separation. The procedure measures the ionic contamination extractable from the surface of printed circuits and assemblies, soldering fluxes, electrical components, etc.

Inductively Coupled Plasma – Optical Emission Spectrometry

Optical Emission Spectrometry (OES) is an analytical technique which identifies traces of metals and uses Inductively Coupled Plasma (ICP) to separate the sample into atoms and ions which, once excited, release electromagnetic radiation of a wavelength characteristic of each element. It determines the basic qualitative and quantitative composition of the analysed sample.

Our chemical lab is also able to determine the carbon and sulphur concentration in metal alloys through a carbon and sulphur analyser (LECO). The application field includes metals such as steel, iron, copper and alloys.

Determining the Contact Angle

The contact angle is a thermodynamic quantity representing a measurement of wettability. This test measures the angle a drop of liquid creates on the surface of a solid. The size of the contact angle depends on the interaction between the substances and the contact surface: the lower the interaction, the greater the contact angle, and the harder it is to wet the solid. From the contact-angle determination it is possible to define surface features such as surface energy.

Glass Transition Temperature (Tg)

The Glass Transition Temperature (Tg) represents the temperature range at which an amorphous material moves from a hard, glassy condition to a more flexible, rubbery condition — the so-called structural relaxation. It can be determined using different instruments:

Coefficient of Thermal Expansion (CTE) with TMA

The Coefficient of Thermal Expansion describes how the size of an object changes in relation to a temperature variation. Usually, substances expand when their temperature changes, and the relative expansion or reduction can occur in all directions (isotropic material).

Time to Delamination (with TMA)

The Time to Delamination is a measurement used to evaluate basic material performance: it provides information about the time the resin and the copper require to separate or delaminate. The test uses the TMA instrument to bring a sample (laminate or printed circuit) to a specific temperature and measures the time necessary for delamination.

Thermogravimetric Analysis with TGA

Thermogravimetric Analysis measures the variation of the sample mass subjected to heating with a controlled increase of temperature. The result includes a thermogram indicating temperature/time on the x-axis and the absolute change or sample-mass percentage on the ordinates (Thermal Decomposition Curve). It is useful to evaluate decomposition and oxidation processes.

Melting Point with DSC

Differential Scanning Calorimetry (DSC) measures the difference between the thermal fluxes in a sample and a reference, both subjected to a controlled temperature variation, providing information about the energy absorbed or released by the sample when it is warmed or cooled.

The melting point of a material is the temperature at which it changes from solid to liquid; during this process all the energy added is consumed as heat of fusion and the temperature remains constant. The melting-point analysis also gives a first impression of the purity of a substance, since some impurities change the fusion range.

Solder Pastes Analysis

Solder pastes are stable, homogeneous suspensions of soldering powder immersed in a liquid flux. By changing the size, distribution and shape of the soldering particles, it is possible to control the rheology and performance of the pastes.

Solder Ball Test — determines the solder-paste re-flow properties during the re-fusion process (IPC TM 650 2.4.43).

Slump Test — defines the vertical and horizontal slump of the solder pastes (IPC TM 650 2.4.35).

Wetting Test — defines the ability of a solder paste to wet an oxidised copper surface and examines the spatter quantity during re-fusion (IPC TM 650 2.4.45).

Determining Water Absorption

The water-absorption test determines the quantity of absorbed liquid in specific environmental conditions. It is affected by factors such as the type of material, additives used, and the temperature and duration of the test, and shows the possible performance of materials in water or humid environments.

Flammability Test

Flammability is the capacity of a material to burn or explode, causing fires or combustion. The level of difficulty necessary to provoke combustion is determined by the flammability test.

Copper Mirror Test

This test detects the active substances inside fluxes. The solder paste or flux is placed on a substrate covered with a light copper layer; the presence (or absence) of active substances causes the removal of the copper layer, revealing the corrosive behaviour of the flux.

Corrosion Test

Corrosion tests are essential to understand how materials behave in severe or ongoing use conditions and to guarantee the achievement of the complete life cycle. They ease the prediction, planning and mitigation of the negative effects that corrosion can have on the materials on which they are used.

Porosity Test

Gest Labs can test samples and materials to evaluate their porosity features and to characterise the empty spaces inside them.