Here, the laser power PL, the focal plane position zFP, the oscillation amplitude a0 and the oscillation frequency f0 were involved as independent variables or factors, respectively. A 4 kW multimode fiber laser IPG YLR was used as the beam source in combination with a Precitec HP-SSL cutting head (Precitec GmbH & Co. KG, Gaggenau, Germany). The beam coming out of the delivery fiber with a diameter of 100 µm was collimated by a 100 mm lens and then focused by a lens with 125 mm focal length. The resultant beam caustic was measured with the Primes MicroSpotMonitor tool . The measurement indicates an actual focal beam radius of about 80 µm and a Rayleigh length or depth of focus of about 1.7 mm, respectively.
BGAs are reflow soldered to PCBs using a mass reflow process. Table 3.Raw data of the cutting trials with a static laser beam. Petring, D. Virtual laser cutting simulation for real parameter optimization. In Proceedings of the 84th Laser Materials Processing Conference , Nagoya, Japan, 19–20 January 2016; pp. 11–20. qa roose microsoft excel tiktokpatel Arntz, D.; Petring, D.; Stoyanov, S.; Jansen, U.; Schneider, F.; Poprawe, R. In-situ visualization of multiple reflections on the cut flank during laser cutting with 1 µm wavelength. Mahrle, A.; Beyer, E. Theoretical estimation of achievable travel rates in inert-gas fusion cutting with fibre and CO2 lasers.
A stack of alternating metallic and ceramic layers with vias interconnecting them. A substrate that uses more than two layers for conductor routing. Plated via holes are used to connect the internal layers to the outer layers. The angle of the vertical portion of a lead with respect to a plane perpendicular to the plane defined by the bottom of the component. The distance between adjacent leads in a defined area of a component.
Leads can readily be formed to a desired configuration. Examples include alumina or glass-ceramic. Ceramics are often used in forming ceramic substrates for the packaging of semiconductor chips.
Specifically to convert a low molecular weight polymer or resin to and insoluble, infusible state. Minute lines appearing in or near the surface of materials such as plastics, usually resulting as a response to environment. Crazing cannot be felt by running a fingernail across it . A chemical action that causes the gradual deterioration of the surface of a metal by oxidation or chemical reaction. The angle between bonding material and a bonding pad.
This phenomenon occurs because, when the peak current is 1.5 A, the pulse energy increases with the pulse duration. The gap between the solidification bulges expands and occupies the position of the pores, and the pores do not increase considerably. Spherical debris is formed by re-solidifying the material on the surface of the workpiece when it meets the flowing working fluid after gasification.
When the pulse duration increases to 60 µs, the depth of the pores deepens, and the local “air cushion” effect occurs. The contact angle is larger than the one presented in Figure 4g. The decrease in maximum cutting speed can be reasoned by the increased interaction area of the oscillating beam in comparison to the static beam. In addition, remarkable relationships between the measured cut edge roughness and the calculated shear stress values are found, as shown in Figure 17.
The accurately scaled configurations or patterns produced to enable the product to be made; photographic films which are created to produce working thick film screens and thin film masks. A group of elements, such as solder bumps, or circuits arranged in rows and columns on a substrate. Holes specifically designed for registration of a substrate. These holes can be located virtually anywhere on the substrate, however, locations are standardized in many cases. A process in which the conductive, resistive, and insulating materials are successively plated to define traces, pads, and elements. The maximum number of defects per every 100 units that are considered to be satisfactory as a process average.