Technical Library | 2023-09-07 14:38:31.0
A repeat customer specializing in high-technology interconnect, sensor, and antenna solutions, partnered with us to dispense small volumes of solder paste (Indium 10.1 SAC305 T6SG 78%m) onto backplane connectors – gold pads 0.175mm x 0.225mm. We performed a test requiring 0.200mm diameter or smaller dots to demonstrate the dispensing capability required.
Technical Library | 2016-09-01 16:21:11.0
Sn3.0Ag0.5Cu (SAC305) is currently the most popular near eutectic lead-free alloy used in the manufacturing processes. Over the last several years, the price of silver has dramatically increased driving a desire for lower silver alloy alternatives. As a result, there is a significant increase in the number of alternative low/no silver lead-free solder alloys available in the industry recently. Our previous study showed that many alternative low silver solder paste materials had good printing and wetting performance as compared to SAC305 solder pastes. However, there is lack of information on the reliability of alternative alloy solder joints assembled using alternative low silver alloy solder pastes.In this paper, we will present the reliability study of lead-free solder joints reflowed using various lead-free alloy solder pastes after thermal cycling test (3000 cycles, 0°C to 100°C). Six different lead-free pastes were investigated. SAC305 solder joints were used as the control. Low and no silver solder pastes and a low temperature SnBiAg solder pastes were also included.
Technical Library | 2009-01-15 00:42:58.0
Tin-silver-copper has received much publicity in recent years as the lead-free solder of choice. SAC305 was endorsed by the IPC Solder Value Product Council in the United States as the preferred option for SMT assembly; most assemblers have transitioned to this alloy for their solder paste requirements. The SAC305 alloy due to its 3.0% content of silver is expensive when compared to traditional 63/37 for this reason many wave assemblers are opting for less costly options such as tin-copper based solders for their wave, selective and dip tinning operations.
Technical Library | 2014-10-02 20:10:07.0
Sn3.0Ag0.5Cu (SAC305) is the most popular near eutectic lead-free alloy used in the manufacturing processes. Over the last several years, the price of silver has dramatically increased driving a desire for lower silver alloy alternatives. As the results, there is a significant increase in the number of alternative low/no silver lead-free solder alloys available in the industry recently.In this paper, we'll present the performance and process capability of various low/no silver alloy solder pastes. Data from printability, wetting test, slump test, solder ball test, voiding, etc… will be discussed and compared with the control SAC305 solder paste. Benefits and concerns of using low/no silver alloy solder paste materials will also be addressed.
Technical Library | 2020-09-23 21:29:25.0
The electronics industry could benefit greatly from using a reliable, manufacturable, reduced temperature, SMT solder material (alloy-composition) which is cost competitive with traditional Sn3Ag0.5Cu (SAC305) solder. The many possible advantages and some disadvantages / challenges are discussed. Until recently, the use of Sn/Bi based materials has been investigated with negative consequences for high strain rate (drop-shock) applications and thus, these alloys have been avoided. Recent advances in alloy "doping" have opened the door to revisit Sn/Bi alloys as a possible alternative to SAC-305 for many applications. We tested the manufacturability and reliability of three low-temperature and one SAC-305 (used as a control) solder paste materials. Two of these materials are doped Sn/Bi/Ag and one is just Sn/Bi/Ag1%. We will discuss the tests and related results. And lastly, we will discuss the prospects, applications and possible implications (based on this evaluation) of these materials together with future actions.
Technical Library | 2021-08-25 16:34:37.0
As the traditional eutectic SnPb solder alloy has been outlawed, the electronic industry has almost completely transitioned to the lead-free solder alloys. The conventional SAC305 solder alloy used in lead-free electronic assembly has a high melting and processing temperature with a typical peak reflow temperature of 245ºC which is almost 30ºC higher than traditional eutectic SnPb reflow profile. Some of the drawbacks of this high melting and processing temperatures are yield loss due to component warpage which has an impact on solder joint formation like bridging, open defects, head on pillow.
Technical Library | 2020-10-27 02:02:17.0
Solder powder size is a popular topic in the electronics industry due to the continuing trend of miniaturization of electronics. The question commonly asked is "when should we switch from Type 3 to a smaller solder powder?" Solder powder size is usually chosen based on the printing requirements for the solder paste. It is common practice to use IPC Type 4 or 5 solder powders for stencil designs that include area ratios below the recommended IPC limit of 0.66. The effects of solder powder size on printability of solder paste have been well documented. The size of the solder powder affects the performance of the solder paste in other ways. Shelf life, stencil life, reflow performance, voiding behavior, and reactivity / stability are all affected by solder powder size. Testing was conducted to measure each of these solder paste performance attributes for IPC Type 3, Type 4, Type 5 and Type 6 SAC305 solder powders in both water soluble and no clean solder pastes. The performance data for each size of solder powder in each solder paste flux was quantified and summarized. Guidance for choosing the optimal size of solder powder is given based on the results of this study.
Technical Library | 2017-04-13 16:14:27.0
The drive to reduced size and increased functionality is a constant in the world of electronic devices. In order to achieve these goals, the industry has responded with ever-smaller devices and the equipment capable of handling these devices. The evolution of BGA packages and leadless devices is pushing existing technologies to the limit of current assembly techniques and materials.As smaller components make their way into the mainstream PCB assembly market, PCB assemblers are reaching the limits of Type 3 solder paste, which is currently in use by most manufacturers.The goal of this study is to determine the impact on solder volume deposition between Type 3, Type 4 and Type 5 SAC305 alloy powder in combination with stainless steel laser cut, electroformed and the emerging laser cut nano-coated stencils. Leadless QFN and μBGA components will be the focus of the test utilizing optimized aperture designs.
Technical Library | 2018-05-17 11:14:52.0
Intermetallic compound (IMC) growth is being studied in earnest in this past decade because of its significant effect the solder joint reliability. It appears that from numerous investigations conducted, excessive growth of IMC could lead to solder joint failure. Leading to this, many attempts has been made to determine the actual IMC thickness. However, precise and true representation of the growth in the actual 3D phenomenon from 2D cross-section investigations has remained unclear. This paper will focus on the measuring the IMC thickness using 3D surface profilometer (Alicona Focus G4). Lead free solder, Sn3.0Ag0.5Cu (SAC305) was soldered onto copper printed circuit board (Cu PCB). The samples were then subjected to thermal cycle (TC) storage process with temperature range from 0 °C to 100 °C for 200 cycles and up to 1000 cycles were completed.
Technical Library | 2019-08-07 22:56:45.0
The requirement to reconsider traditional soldering methods is becoming more relevant as the demand for bottom terminated components (QFN/BTC) increases. Thermal pads under said components are designed to enhance the thermal and electrical performance of the component and ultimately allow the component to run more efficiently. Additionally, low voiding is important in decreasing the current path of the circuit to maximize high speed and RF performances. The demand to develop smaller, more reliable, packages has seen voiding requirements decrease below 15 percent and in some instances, below 10 percent.Earlier work has demonstrated the use of micro-fluxed solder preforms as a mechanism to reduce voiding. The current work builds upon these results to focus on developing an engineered approach to void reduction in leadless components (QFN) through increasing understanding of how processing parameters and a use of custom designed micro-fluxed preforms interact. Leveraging the use of a micro-fluxed solder preform in conjunction with low voiding solder paste, stencil design, and application knowhow are critical factors in determining voiding in QFN packages. The study presented seeks to understand the vectors that can contribute to voiding such as PCB pad finish, reflow profile, reflow atmosphere, via configuration, and ultimately solder design.A collaboration between three companies consisting of solder materials supplier, a power semiconductor supplier, and an electronic assembly manufacturer worked together for an in-depth study into the effectiveness of solder preforms at reducing voiding under some of the most prevalent bottom terminated components packages. The effects of factors such as thermal pad size, finish on PCB, preform types, stencil design, reflow profile and atmosphere, have been evaluated using lead-free SAC305 low voiding solder paste and micro-fluxed preforms. Design and manufacturing rules developed from this work will be discussed.
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