Technical Library | 2011-04-07 14:50:29.0
Quad Flat No Leads (QFN) package designs receive more and more attention in electronic industry nowadays. This package offers a number of benefits including (1) small size, such as a near die-sized footprint, thin profile, and light weight; (2) easy PCB t
Technical Library | 2023-12-18 21:07:29.0
Selective soldering utilises a nozzle to apply solder to components on the underside of printed circuit boards (PCBs). This nozzle can be moved to either perform dips (depositing solder to a single component) or draws (applying solder to several components in a single movement). The selective soldering methodology thereby allows the process to be tailored to specific joints and allows multiple nozzle types to be used if required on the circuit board. Nozzles can vary by size (internal diameter) and shape (making them suitable for different process types). This is all dictated by board design and process requirements. Selection of the nozzle type is dependent upon the product to be soldered and the desired cycle time. Examples of different nozzle types are shown here. Hand-load selective systems must be programmed with the parameters for multiple solder joints. However, many in-line systems are designed to be modular. This modularity allows for multiple solder stations with different conditions/nozzles to achieve low cycle times. Figure 1 shows the two distinct types of selective soldering systems offered by Pillarhouse International Ltd.
Technical Library | 2023-09-18 14:10:01.0
As with many advancements in the electronics industry, consumer electronics is driving the trends for electronic packaging technologies toward reducing size and increasing functionality. Microelectronics meeting the technology needs for higher performance, reduced power consumption and size, and off the- shelf availability. Due to the breadth of work being performed in the area of microelectronics packaging/components, this report limits it presentation to board design, manufacturing, and processing parameters on assembly reliability for leadless (e.g., quad flat no-lead (QFN) or a generic term of bottom termination component (BTC)) packages. This style of package was selected for investigation because of its significant growth, lower cost, and improved functionality, especially for use in an RF application.
Technical Library | 2020-04-16 05:52:45.0
Based on the dual pot, we developed an independent dual z-axis control dual pot for FLEX-i2! There are 5 operation modes available with the independent dual Z axis: only solder pot1, only solder pot2, first solder pot 1 then solder pot2, first solder pot2 then solder pot1, solder pot1 and solder pot2 together. In specific applications, solder pot1 can be selected with large nozzle soldering heat-absorbing large parts, solder pot2 use small nozzle soldering heat-absorbing small parts, so as to achieve both soldering effect and productivity. Also can use same nozzle, dual axis simultaneously solder two same plate to increase productivity. To get the maximum flexibility and productivity! FLEX-i2 is a compact in line selective soldering machine, equipped with high precision servo control system, jet valve, live-on camera, upper preheating etc, which can provide a high flexibility and efficiency soldering process. The maximum soldering size can reach 420mm*490mm!
Technical Library | 2024-07-24 01:04:35.0
Quad Flat No Leads (QFN) package designs receive more and more attention in electronic industry recently. This package offers a number of benefits including (1) small size, such as a near die size footprint, thin profile, and light weight; (2) easy PCB trace routing due to the use of perimeter I/O pads; (3) reduced lead inductance; and (4) good thermal and electrical performance due to the adoption of exposed copper die-pad technology. These features make the QFN an ideal choice for many new applications where size, weight, electrical, and thermal properties are important. However, adoption of QFN often runs into voiding issue at SMT assembly. Upon reflow, outgassing of solder paste flux at the large thermal pad has difficulty escaping and inevitably results in voiding. It is well known that the presence of voids will affect the mechanical properties of joints and deteriorate the strength, ductility, creep, and fatigue life. In addition, voids could also produce spot overheating, lessening the reliability of the joints.
Technical Library | 2023-08-04 15:38:36.0
The MicroLeadFrame® (MLF®)/Quad Flat No-Lead (QFN) packaging solution is extremely popular in the semiconductor industry. It is used in applications ranging from consumer electronics and communications to those requiring high reliability performance, such as the automotive industry. The wide acceptance of this packaging design is primarily due to its flexible form factors, size, scalability and thermal dissipation capabilities. The adaptation and acceptance of MLF/QFN packages in automotive high reliability applications has led to the development of materials and processes that have extended its capabilities to meet the performance and quality requirements. One of process developments that is enabling the success of the MLF/QFN within the automotive industry has been the innovation of side wettable flanks that provide the capability to inspect the package lead to printed circuit board (PCB) interfaces for reliable solder joints. Traditionally, through-board X-ray was the accepted method for detecting reliable solder joints for leadless packages. However, as PBC layer counts and routing complexities have increased, this method to detect well-formed solder fillets has proven ineffective and incapable of meeting the inspection requirements. To support increased reliability and more accurate inspection of the leadless package solder joints, processes to form side-wettable flanks have been developed. These processes enable the formation of solder fillets that are detectable using state-of-the-art automated optical inspection (AOI) equipment, providing increased throughput for the surface mount technology (SMT) processes and improved quality as well.
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