Gas Chromatography-Mass Spectrometry Analysis

• The copper plates were coated with different films: a) a new HTOSP film; b) an industry-standard OSP film; and c) another industrial OSP film. Approximately 0.74-0.79 mg of the OSP film was scraped from the copper plate for testing.
• An H/P6890GC/MS instrument and syringe-free syringes were used in the experiment. Syringe-free syringes can directly desorb solid samples in the sample chamber and transfer them to the gas chromatograph’s inlet for analysis.
• A Restek RT-1 gas chromatography column (0.25 mm ID * 30 m, film thickness of 1.0 μm) was employed in the experiment. The temperature rise program for the column ranged from 35°C to 325°C at a rate of 15°C/min.
• Mass spectrometry detected volatile organic compounds with a mass/charge ratio of 10-700 daltons, and the retention time of small organic molecules was recorded.

Thermogravimetric Analysis (TGA)

• The new HTOSP film, an industry-standard OSP film, and another industrial OSP film were tested using approximately 17.0 mg of scraped OSP film from copper plates.
• TGA tests were performed using TA Instruments’ 2950TA under nitrogen protection, with temperatures ranging from room temperature to 700°C at a rate of 10°C/min.

Photoelectron Spectroscopy (XPS)

• XPS, also known as ESCA, is a method for chemical surface analysis that can measure the chemical composition of coating surfaces.
• The HTOSP film and industry-standard OSP film were analyzed using XPS before and after lead-free reflow treatments.

Through-Hole Solderability Test

• Solderability test boards (STVs) coated with HTOSP film and industry-standard OSP film underwent high-temperature, lead-free reflow treatments and wave soldering to assess through-hole solderability.
• STVs were tested under different reflow conditions to determine the number of correctly filled through-holes, with acceptance criteria for solder filling specified.
• Each STV contained 1196 through-holes of various sizes and pad types.

Test of Solderability Through a Tin-Dip Balance

• The solderability of OSP film was evaluated using a tin-dip balance test with HTOSP film and lead-free reflow treatments up to 262°C peak temperature.
• Reflow was conducted following specific standards using automated wet balance testing equipment, non-clean flux, and SAC305 alloy solder.

Welding Bonding Force Test

Measurement of Welding Bonding Force in PCB Manufacturing

In the process of PCB manufacturing, the welding bonding force is a critical parameter that needs to be carefully measured. One common method of measuring this force is through shear force testing.

During a recent study, HTOSP film was applied to BGA pad test boards with a diameter of 0.76 mm. The film was coated at two different thicknesses – 0.25 μm and 0.48 μm, respectively. These test boards then underwent three lead-free reflow treatments, with the maximum temperature reaching 262°C.

Measuring the welding bonding force is essential to ensure the reliability and quality of PCBs, especially in high-temperature environments where solder joints are subjected to significant stress.