Patents by Inventor Cheng-En Ho

Cheng-En Ho has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20110227769
    Abstract: A method for testing a digital to analog converter, which operates in an undersampling environment, wherein signals of a tested DAC and a signal generator are modulated by a PWM device and then processed by a digital processing circuit to generate a digital signal, whereby is formed a low-speed equivalent ADC. The signal generator is provided by uniform-distribution random test patterns, and the signal generator generates an uniform-distribution random analog signal to the equivalent ADC. Thereby, the test error caused by the non-ideality of the signal generator is corrected, and the tested circuit can work in a full speed.
    Type: Application
    Filed: March 19, 2010
    Publication date: September 22, 2011
    Inventors: Chun-Wei Lin, Cheng-En Ho
  • Publication number: 20110139314
    Abstract: A method for inhibiting the growth of a nickel-copper-tin intermetallic (i.e. (Ni,Cu)3Sn4) layer at the (Cu,Ni)6Sn5/nickel interface of a solder joint is described as follows. A Sn—Ag—Cu solder alloy with a Cu-content of 0.5˜1 weight percent (wt. %) is provided. The solder alloy is disposed on a surface finish of a soldering pad, having a nickel-based metallization layer. A material of the solder alloy further includes palladium. The solder alloy is joined with the surface finish, so as to form the solder joint containing palladium that enables to inhibit the growth of the undesired (Ni,Cu)3Sn4 layer between the (Cu,Ni)6Sn5 and nickel in the subsequent use at temperatures ranging from 100° C. to 180° C.
    Type: Application
    Filed: May 10, 2010
    Publication date: June 16, 2011
    Inventors: Cheng-En Ho, Chi-Ming Lin
  • Patent number: 7950565
    Abstract: A high speed ball shear machine is adapted for removing a metal bump fixed on a substrate. The high speed ball shear machine includes a fixing base, a shear tool, and a metal bump catcher. The substrate is fixed on the top surface of the fixing base. The shear tool is disposed above the top surface. The fixing base is adapted for being translated along a translation path relative to the shear tool, wherein the translation path is a straight path. When the fixing base translates along the path, the metal bump is driven to strike the shear tool so as to separate itself from the substrate. The metal bump catcher, which is adapted for catching the drop bump after the striking, is disposed on the side wall of the fixing base. The bump catcher has a fillister with a configuration depicted in the figures of this invention.
    Type: Grant
    Filed: September 8, 2009
    Date of Patent: May 31, 2011
    Assignee: Yuan Ze University
    Inventors: Cheng-En Ho, Han-Lin Chung
  • Publication number: 20100301100
    Abstract: A high speed ball shear machine is adapted for removing a metal bump fixed on a substrate. The high speed ball shear machine includes a fixing base, a shear tool, and a metal bump catcher. The substrate is fixed on the top surface of the fixing base. The shear tool is disposed above the top surface. The fixing base is adapted for being translated along a translation path relative to the shear tool, wherein the translation path is a straight path. When the fixing base translates along the path, the metal bump is driven to strike the shear tool so as to separate itself from the substrate. The metal bump catcher, which is adapted for catching the drop bump after the striking, is disposed on the side wall of the fixing base. The bump catcher has a fillister with a configuration depicted in the figures of this invention.
    Type: Application
    Filed: September 8, 2009
    Publication date: December 2, 2010
    Inventors: Cheng-En Ho, Han-Lin Chung
  • Publication number: 20100127047
    Abstract: A method of inhibiting a formation of palladium-nickel-tin (Pd—Ni—Sn) intermetallic in solder joints is described as follows. Firstly, a solder alloy is provided. Then, at least one of a trace of copper and a trace of zinc is doped into the solder alloy. Afterward, the solder alloy is disposed on the Pd-bearing surface finish, such as a Pd/Ni bi-layer or a Au/Pd/Ni tri-layer. Next, the solder alloy is soldered with the surface finish as solder joints. During the soldering, the Cu and Zn will incorporate into the soldering reaction, forming copper-palladium-nickel-tin intermetallic and zinc-palladium-nickel-tin intermetallic, replacing the Pd—Ni—Sn respectively. Consequently, the addition of Cu and/or Zn into solders will inhibit the undesirable Pd—Ni—Sn intermetallic to form in the solder joints.
    Type: Application
    Filed: January 13, 2009
    Publication date: May 27, 2010
    Applicant: Yuan Ze University
    Inventors: Cheng-En Ho, Wei-Hsiang Wu, Cheng-Shiuan Lin
  • Publication number: 20090294409
    Abstract: A method for inhibiting electromigration-induced phase segregation suitable for solder joint configurations used in a chip package is described as following. First, a chip package including a wiring board, a chip and numbers of solder joints is provided, wherein the chip is disposed on the wiring board, and the solder joints are disposed between the chip and the wiring board to electrically connect the chip to the wiring board. Next, a first current and a second current are alternately applied to a side of the solder joints, wherein flowing directions of the first current and the second current are opposite. The current density of the first current is 103˜105 A/cm2, and the current density of the second current is 103˜105 A/cm2.
    Type: Application
    Filed: June 2, 2008
    Publication date: December 3, 2009
    Applicant: Yuan Ze University
    Inventors: Cheng-En Ho, Wei-Hsiang Wu
  • Publication number: 20080280785
    Abstract: A fluidic nano/micro array chipset comprises a microarray filling chip and a nano/micro array stamping chip. There are a plurality of sample containers and a plurality of nano/micro channels on the top of the microarray filling chip, and a plurality of nano/micro-scaled micro filling holes on the bottom of the microarray filling chip. Each nano/micro channel is connected to one of the sample containers and leads the sample solution in that sample container to the corresponding micro filling hole. The nano/micro array stamp chip comprises a plurality of stamping heads arranged in an array pattern, with a body part of the stamp chip and a plurality of space channels forming hydrophobic areas. Each sample solution is stored in the body of the stamp chip, and is transported by the corresponding stamping head to the stamping part of this stamping head.
    Type: Application
    Filed: April 28, 2008
    Publication date: November 13, 2008
    Applicant: NATIONAL TSING HUA UNIVERSITY
    Inventors: Fan Gang Tseng, Cheng En Ho
  • Publication number: 20030219623
    Abstract: A solder joint structure comprises a solder of a Sn alloy especially having Cu element contained therein, a contact region having a Ni layer been composed therein. In which, by means of controlling the Cu concentration to select an interface reaction product for reducing the consumption rate of the Ni layer of the contact region so as to provide an durable strength therefore.
    Type: Application
    Filed: April 16, 2003
    Publication date: November 27, 2003
    Inventors: Cheng Heng Kao, Cheng En Ho, L. C. Shiau
  • Patent number: 6602777
    Abstract: The present invention relates to a method for controlling the formation of the intermetallic compounds in solder joints, The types of the intermetallic compounds between the SnAgCu solders and the Ni-bearing substrate can be controlled by adjusting the copper concentration in the SnAgCu solders. If the SnAgCu solder has a copper concentration higher than or equivalent to 0.6 wt. %, the soldering intermetallic compound includes a continuous (Cu1−xNix)6Sn5 layer. If the copper concentration of the SnAgCu solders is lower than or equivalent to 0.4 wt. %, the soldering intermetallic compound includes a continuous (Ni1−yCuy)3Sn4 layer and a non-continuous (Cu1−xNix)6Sn5 layer. If the copper concentration of the SnAgCu solders is between 0.4 wt. % to 0.6 wt. %, the soldering intermetallic compound includes the continuous (Cu1−xNix)6Sn5.
    Type: Grant
    Filed: March 20, 2002
    Date of Patent: August 5, 2003
    Assignee: National Central University
    Inventors: Cheng-Heng Kao, Cheng-En Ho
  • Publication number: 20030132271
    Abstract: The present invention relates to a method for controlling the formation of the intermetallic compounds in solder joints, The types of the intermetallic compounds between the SnAgCu solders and the Ni-bearing substrate can be controlled by adjusting the copper concentration in the SnAgCu solders. If the SnAgCu solder has a copper concentration higher than or equivalent to 0.6 wt. %, the soldering intermetallic compound includes a continuous (Cu1−xNix)6Sn5 layer. If the copper concentration of the SnAgCu solders is lower than or equivalent to 0.4 wt. %, the soldering intermetallic compound includes a continues (Ni1−yCuy)3Sn4 layer and a non-continuous (Cu1−xNix)6Sn5 layer. If the copper concentration of the SnAgCu solders is between 0.4 wt. % to 0.6 wt.
    Type: Application
    Filed: March 20, 2002
    Publication date: July 17, 2003
    Inventors: Cheng-Heng Kao, Cheng-En Ho