Technical Library | 2024-03-19 15:53:34.0
Underfill is a composite material usually made of an epoxy polymer that fills gaps between a chip and its carrier or a finished package and the PCB substrate to connect the chip to the board.
Technical Library | 2020-12-02 20:36:54.0
Industry 4.0 is a topic of much discussion within the electronics manufacturing industry. Manufacturers and vendors are trying to come to terms with what that means. In the most simplistic of terms, Industry 4.0 is a trend toward automation and data exchange within the manufacturing process. This basically requires connectivity and communication from machine to machine within the manufacturing line. The challenge is to collect data from each of the systems within the line and make that data available to the rest of the machines. Without test and inspection, there is no Industry 4.0. The whole purpose of test and inspection is to collect actionable data that may be used to reduce defects and maximize efficiency within the manufacturing line. The goal is to minimize scrap and get a really good handle on those process parameters that need to be put in place to manufacture products the right way the first time. For maximum efficiency, three inspection systems are required within the production line. These are solder paste inspection (SPI) post-solder deposition, automated optical inspection (AOI) post-placement, and AOI post-reflow. This requires a substantial investment; however, the combination of all three inspection machines is really the only true way to provide feedback for each stage of the manufacturing process.
Technical Library | 2023-09-16 06:31:54.0
Discover our specialized reflow oven tailored for efficient soldering in 5G modular and radiator assembly. Achieve precise and reliable connections for high-performance electronics.
Technical Library | 2019-05-21 17:38:55.0
Last month we presented Flip Chip Rework.As promised, this month we follow up with attachment techniques. Flip chip assembly is a key technology for advanced packaging of microelectronic circuits. It allows attachment of a bare chip to a packaging substrate in a face-down configuration, with electrical connections between the chip and substrate via conducting “bumps.” Flip chip technology was first invented by IBM for mainframe computer application in the early 1960s. Semiconductor devices are mounted face down and electrically and mechanically connected to a substrate (Figure 1). IBM called this manufacturing process a C4 process (controlled collapse chip connection).
Technical Library | 2019-05-21 17:34:08.0
Flip chip components have been gaining popularity in the electronics industry since their introduction in the 1960s. Advances in attach methods and adhesives, as well as the drive for smaller and faster electronic devices made the technology take off. The basic premise of the flip chip is that the chip (semiconductor device) is mounted flipped from the traditional position. The traditional method of mounting a die is to mount it on a lead frame with the circuit and bond pads face up. The bond pads then receive a bond wire which then connects to the proper lead on the lead frame. Flip chips are mounted face down onto a substrate using small bumps on the bond pads to make direct electrical connection to their respective pads on the substrate. Stay tuned for more information on attachment techniques next month. This article will focus on how to rework flip chips.
Technical Library | 2020-12-07 15:26:06.0
Temperature cycling testing is a method of accelerated life testing done to PCCs that are exposed to normal operation temperature variations over its lifetime. During the testing, intermittent "open" failures can first occur at the hot and cold extremes of the test, exposing weaknesses in the design and assembly. A poor/weak solder joint fatigues, a via trace or barrel cracks, loose connections or a component fails all causing an intermittent open. When not at extreme temperatures, the PCC assembly relaxes, the "open" closes creating electrical connectivity. If you are monitoring the PCC under test in-situ you will know that an intermittent failure has occurred, and the test could be stopped for inspection. If in-situ monitoring was not implemented, you would not know if there were intermittent failures or not. The PCC gets powered up and works fine at room temperature.
Technical Library | 2020-04-14 16:00:20.0
The number of through hole connections on a circuit assembly are decreasing with the drive toward miniaturization. When these assemblies are manufactured in high volumes the most convenient method is selective soldering. Although selective soldering is very well introduced in automotive and industrial applications it can also be a very efficient method to solder high volume consumer products.
Technical Library | 2008-10-15 20:16:12.0
Solder paste dispensing is usually considered a slow process. Due to the speed advantages, screen printing is used to apply solder paste whenever possible. However, screen printing is not always an option. Leveraging the high speed of piezo drive technology opens the door to a broad range of solder paste dispensing applications. The ability to dispense dots under 300-μm diameter, even as small as 125 μm, enables BGA rework, small geometry deposits for miniaturized passive components, electrical connections in recessed cavities, and RF shield attach for handheld devices.
Technical Library | 2019-05-21 17:20:36.0
Die attach material selection and process implementation play crucial roles in any microelectronic assembly. The chosen attach methods ultimately affect die stress, functionality, thermal management, and reliability of the assembly. Die attach applications are designed to optimize mechanical attachment of the die to the substrate, to create a thermal path from the die to the substrate, and to create an electrical path for a ground plane connection. Some of the more commonly used die attach materials in the microelectronics industry today are epoxies,polyimides, thermoplastics, silicones, solders, and special low outgassing, low stress, anisotropic adhesives.
Technical Library | 2019-06-04 10:19:46.0
Interconnection technology relies very heavily on the ability of the conductors on a printed wiring assembly to maintain reliable signal integrity. Harsh environmental factors can precipitate a loss of conductivity due to oxidation and corrosion. Connections are typically soldered or inserted using pressure fitted connectors to obtain enough surface contact to meet the electrical conductivity requirements. In pressure contacts, surface integrity is especially critical where the abrasive effects of retraction and insertion can wear off the metallic finish from the contact area. This can expose the underlying copper or nickel and lead to increased resistance at the contact points. These types of conductors are frequently found in card edge connectors where the terminations are plated with a layer of nickel and gold (frequently referred to as gold fingers). A hard gold is typically used containing very small amounts of nickel and cobalt to increase the wear resistance.
