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 | 2007-01-31 15:17:04.0
The goal of this project is to evaluate the reliability of lead-free BGA solder joints with a variety of different pad sizes using several different BGA rework methods. These methods included BGAs reworked with both flux only and solder paste attachment techniques and with or without the use of the BEST stay in place StencilQuick™. The daisy chained test boards were placed into a thermal test chamber and cycled between -25ºC to 125ºC over a 30 minute cycle with a 30 minute dwell on each end of the cycle. Each BGA on the board was wired and the continuity assessed during the 1000 cycles the test samples were in the chamber.
Technical Library | 2016-08-24 06:15:35.0
From consumer electronics to systems control, automotive technology to aviation and aerospace – today, electronics are absolutely essential in many sectors. They increasingly replace mechanical components, eliminating wear and tear and thereby extending the service life. What is easily forgotten in this regard is that electronics are also subject to the laws of mechanics. Mechanical test equipment is crucial to test components for the secure hold of welded, soldered or adhesive bonds. A new, mechanically intricate test probe with universal clamping jaws, that can even grasp the individual bonding wires, is in line with the trend toward ever smaller components. Serving as an actuator for these is a micro drive that can be precisely controlled using a miniaturised motion controller to relieve the control unit in the test device.
Technical Library | 2016-11-17 14:37:41.0
With increasing LED development and production, thermal issues are becoming more and more important for LED devices, particularly true for high power LED and also for other high power devices. In order to dissipate the heat from the device efficiently, Au80Sn20 alloy is being used in the industry now. However there are a few drawbacks for Au80Sn20 process: (1) higher soldering temperature, usually higher than 320°C; (2) low process yield; (3) too expensive. In order to overcome the shortcomings of Au80Sn20 process, YINCAE Advanced Materials, LLC has invented a new solderable adhesive – TM 230. Solderable adhesives are epoxy based silver adhesives. During the die attach reflow process, the solder material on silver can solder silver together, and die with pad together. After soldering, epoxy can encapsulate the soldered interface, so that the thermal conductivity can be as high as 58 W/mk. In comparison to Au80Sn20 reflow process, the solderable adhesive has the following advantages: (1) low process temperature – reflow peak temperature of 230°C; (2) high process yield – mass reflow process instead of thermal compression bonding process; (3) low cost ownership. In this paper we are going to present the die attach process of solderable adhesive and the reliability test. After 1000 h lighting of LED, it has been found that there is almost no decay in the light intensity by using solderable adhesive – TM 230.
Technical Library | 2015-08-13 15:52:40.0
Pad cratering has become more prevalent with the switch to lead free solders and lead free compatible laminates. This mainly is due to the use of higher reflow temperature, stiffer Pb-free solder alloys, and the more brittle Pb-free compatible laminates. However, pad cratering is difficult to detect by monitoring electric resistance since pad cratering initiates before an electrical failure occurs. Several methods have been developed to evaluate laminate materials' resistance to pad cratering. Pad-solder level tests include ball shear, ball pull and pin pull. The detailed methods for ball shear, ball pull, and pin pull testing are documented in an industry standard IPC-9708. Bansal, et al. proposed to use acoustic emission (AE) sensors to detect pad cratering during four-point bend test. Currently there is an industry-working group working on test guidelines for acoustic emission measurement during mechanical testing.
Technical Library | 2019-09-24 15:41:53.0
This paper focuses on three different coating material groups which were formulated to operate under high thermal stress and are applied at printed circuit board manufacturing level. While used for principally different applications, these coatings have in common that they can be key to a successful thermal management concept especially in e-mobility and lighting applications. The coatings consist of: Specialty (green transparent) liquid photoimageable solder masks (LPiSM) compatible with long-term thermal storage/stress in excess of 150°C. Combined with the appropriate high-temperature base material, and along with a suitable copper pre-treatment, these solder resists are capable of fulfilling higher thermal demands. In this context, long-term storage tests as well as temperature cycling tests were conducted. Moreover, the effect of various Cu pre-treatment methods on the adhesion of the solder masks was examined following 150, 175 and 200°C ageing processes. For this purpose, test panels were conditioned for 2000 hours at the respective temperatures and were submitted to a cross-cut test every 500 h. Within this test set-up, it was found that a multi-level chemical pre-treatment gives significantly better adhesion results, in particular at 175°C and 200°C, compared with a pre-treatment by brush or pumice brush. Also, breakdown voltage as well as tracking resistance were investigated. For an application in LED technology, the light reflectivity and white colour stability of the printed circuit board are of major importance, especially when high-power LEDs are used which can generate larger amounts of heat. For this reason, a very high coverage power and an intense white colour with high reflectivity values are essential for white solder masks. These "ultra-white" and largely non-yellowing LPiSM need to be able to withstand specific thermal loads, especially in combination with high-power LED lighting applications. The topic of thermal performance of coatings for electronics will also be discussed in view of printed heatsink paste (HSP) and thermal interface paste (TIP) coatings which are used for a growing number of applications. They are processed at the printed circuit board manufacturing level for thermal-coupling and heat-spreading purposes in various thermal management-sensitive fields, especially in the automotive and LED lighting industries. Besides giving an overview of the principle functionality, it will be discussed what makes these ceramic-filled epoxy- or silicone-based materials special compared to using "thermal greases" and "thermal pads" for heat dissipation purposes.
Technical Library | 2015-02-19 16:54:34.0
Pad cratering is an important failure mode besides crack of solder joint as it’ll pass the regular test but have impact on the long term reliability of the product. A new pin pull test method with solder ball attached and positioning the test board at an angle of 30º is employed to study the strength of pad cratering. This new method clearly reveals the failure mechanism. And a proper way to interpret the finite element analysis (FEA) result is discussed. Impact of pad dimension, width and angle of copper trace on the strength is included. Some findings not included in previous research could help to guide the design for better performance
Technical Library | 2019-05-08 21:52:28.0
Cold ball pull testing is used to validate the resistance of PCB pad cratering for the different ultra-low loss dielectrics materials (Dk=3~4.2 and Df
Technical Library | 2023-05-02 19:06:43.0
As 0402 has become a common package for printed circuit board (PCB) assembly, research and development on mounting 0201 components is emerging as an important topic in the field of surface mount technology for PWB miniaturization. In this study, a test vehicle for 0201 packages was designed to investigate board design and assembly issues. Design of Experiment (DOE) was utilized, using the test vehicle, to explore the influence of key parameters in pad design, printing, pick-andplace, and reflow on the assembly process. These key parameters include printing parameters, mounting height or placement pressure, reflow ramping rate, soak time and peak temperature. The pad designs consist of rectangular pad shape, round pad shape and home-based pad shape. For each pad design, several different aperture openings on the stencil were included. The performance parameters from this experiment include solder paste height, solder paste volume and the number of post-reflow defects. By analyzing the DOE results, optimized pad designs and assembly process parameters were determined.
Technical Library | 2023-05-02 19:03:34.0
The demand for 0201 components in consumer products will increase sharply over the next few years due to the need for miniaturization. It is predicted that over 20 billion 0201 components will be used in more than one billion cell phones worldwide by the year 2003. Therefore, research and development on 0201 assembly is becoming a very hot topic. The first step to achieve a successful assembly process is to obtain a good PCB design for 0201 packages. This paper presents the data and criteria of PCB design for 0201 packages, including the pad design for 0201 components, and the minimum pad spacing or component clearance between 0201 components or between 0201 and other components. A systematic study on pad design and pad spacing was undertaken, using two test vehicles and three Design of Experiments (DOEs). In the first DOE, 2 out of 18 types of 0201 pad designs were selected based on process yield. The second DOE was focused on pad spacing, including 10mil, 8mil, 6mil and 4mil. The third experiment was final optimization, using two types of optimized pad designs with 10mil, 8mil and 6mil pad spacing. Through the above experiments, the design guideline for PCB layout for 0201 packages and the assembly process capability are identified.
