Showing papers on "Stamping published in 2001"

Forming an optical element on the surface of a light emitting device for improved light extraction

Abstract: Provided is a light emitting device including a Fresnel lens and/or a holographic diffuser formed on a surface of a semiconductor light emitter for improved light extraction, and a method for forming such light emitting device. Also provided is a light emitting device including an optical element stamped on a surface for improved light extraction and the stamping method used to form such device. An optical element formed on the surface of a semiconductor light emitter reduces reflective loss and loss due to total internal reflection, thereby improving light extraction efficiency. A Fresnel lens or a holographic diffuser may be formed on a surface by wet chemical etching or dry etching techniques, such as plasma etching, reactive ion etching, and chemically-assisted ion beam etching, optionally in conjunction with a lithographic technique. In addition, a Fresnel lens or a holographic diffuser may be milled, scribed, or ablated into the surface. Stamping, an alternative method for forming an optical element, can also be used to form a Fresnel lens or a holographic diffuser on the surface of a semiconductor light emitter. Stamping includes pressing a stamping block against the surface of a light emitting diode. The stamping block has a shape and pattern that are the inverse of the desired optical element. Optionally, stamping can be done before, after, or concurrently with wafer-bonding. Alternatively, a material can be stamped and later bonded to the semiconductor light emitter.

Semiconductor package with metal pads

Abstract: A semiconductor package is disclosed, such as QFN, SON. The semiconductor package includes a die, a package body for protection of a die, and a plurality of leads. A metal pad formed by some partial downside surface of each lead is located on a downside surface of the package body with coplanarity. Each lead has a cutting surface exposed on a corresponding lateral surface of the package body. The cutting surface has an interval with the plane of forming the metal pads by means of selectively self-etching the leads or stamping to bend the leads in order to avoid forming a cutting sharp edge in the brim of the metal pad after cutting.

Process for the manufacture of a part with very high mechanical properties, formed by stamping of a strip of rolled steel sheet and more particularly hot rolled and coated

Abstract: A process for the manufacture of a part with very high mechanical properties, formed by stamping of a strip of rolled steel sheet and more particularly hot rolled and coated with a metal or metal alloy ensuring protection of the surface and the steel, whereby: the steel sheet is cut to obtain a steel sheet blank, the steel sheet blank is stamped to obtain the part, an alloyed intermetallic compound is applied to the surface, before or after the stamping, ensuring protection against corrosion, against steel decarburization, which intermetallic compound may provide a lubrication function, the excess material from the steel sheet required for the stamping operation is trimmed.

Carrier with metal bumps for semiconductor die packages

Abstract: A carrier for a semiconductor die package is disclosed. In one embodiment, the carrier includes a metal layer and a plurality of bumps formed in the metal layer. The bumps can be formed by stamping.

Rubber stamping for plastic electronics and fiber optics

Abstract: Microcontact printing (μCP) is a low-cost technique for rubber stamping that combines the high spatial resolution of sophisticated forms of photolithography with capabilities (e.g., single-step patterning of large areas and nonplanar surfaces) that are not present in other approaches. μCP will be useful for applications where established methods are ineffective. Two areas are particularly promising: (1) plastic electronics, where the chemical incompatibility of the constituent materials with common photoresists and developers can preclude the use of photolithography, and where μCP with rotating cylindrical stamps forms an excellent match with the type of reel-to-reel processing that is envisioned for these systems; and (2) new classes of optical-fiber and microcapillarybased devices, where μCP allows highresolution (∼0.2 μm) circuits, photomasks, and actuators to be printed directly on the highly curved surfaces of cylinders with submillimeter diameters. This article describes some highlights of our work in these and related areas.

Process and equipment for manufacture of advanced composite structures

Abstract: A process for continuous, tailored lamination of aligned composite materials in such a way that either pre-formed or pre-consolidated sheets are made available for subsequent infusion molding or stamping processes, the process comprising the steps of: material placement, consolidation/stabilization, cut and kit, fabrication, and final trim. A tailored blank machine is also described. The blank machine includes a series of material placement heads arranged in a linear or serial fashion along a single moving placement table, wherein each head lays down a single angle of the prescribed stacking sequence as the conveyer passes under the head at a constant speed wherein the angle is proportional to head traverse rate divided by conveyer speed.

Forming-limit diagrams of aluminum tailor-welded blank weld material

Abstract: The current work develops forming-limit diagrams (FLDs) for weld materials in aluminum tailorwelded blanks (TWBs) under biaxial stretching conditions. Aluminum TWBs consist of multiple-thickness and alloy sheet materials welded together into a single, variable-thickness blank. The manufacture of TWBs and their application in automotive body panels requires their constituent weld material to deform under biaxial loading during sheet-metal stamping. The weld geometry is typically nonuniform and relatively small, causing difficulty if one attempts to determine the weld metal FLDs via traditional experimental methods. The subject work primarily relies on theoretical FLD calculation techniques using the Marciniak and Kuczynski (M-K) method. This numerical technique requires the use of material constants and levels of initial material imperfection that have been experimentally determined using unique miniature tensile specimens to isolate and characterize the weld metal. The experimental and numerical work, together with statistical analysis of the level of initial imperfection, allows generation of both an average and safe FLD. The weld metals studied in this work were produced via autogeneous gas tungsten arc welding of a 1- to 2-mm-thick 5000 series aluminum alloy sheet.

Functional element arrangement, functional element, auxiliary assembly element, assembled component and method for producing an assembled component

Abstract: A functional element arrangement which includes a functional element which is to be mounted on a component, especially but not exclusively on a brittle or non-rigid component made of a material containing cavities or pores, e.g. plastic, wood, metal foams, plastic or metal filled with hollow bodies, or another relatively soft material, selectively embodied as a sandwich construction or as a composite material e.g. in the form of a single layered or multilayered structure comprising, for example, two layers of sheet metal or plastic and a core made of one of the above-mentioned materials. The invention is characterized in that it is provided with an auxiliary assembly element which enables the functional element to be blocked using forming techniques when it is mounted on the component in a riveting process or a stamping and riveting process. The invention is further characterized in that, preferably, at least one device is provided to ensure rotational security between the functional element and the component and/or between the auxiliary assembly element and the component. The invention also relates to a functional element, an auxiliary assembly element, an assembled component and various methods for producing assembled components.

Metal superplasticity enhancement and forming process

Abstract: A shaped metallic component is formed by friction stirring at least a segment of a single piece of bulk metal to impart superplasticity thereto and thereby yield a single superplastic metal blank from the single piece of bulk metal. The metal blank is then deformed by a metal deformation process such as forging, rolling, drawing, bending, extruding, gas forming, punching, and stamping.

Next generation stamping dies — controllability and flexibility

Abstract: In sheet metal forming, external energy is transferred to sheet metal through a set of tooling to plastically deform a workpiece. The design of the tooling and its associated forming process parameters play important roles in this manufacturing process since they directly affect the quality and cost of the final product. With increasing demands from customers, government regulations, and global competition, the controllability and flexibility of stamping dies have been challenged. In this paper, we will summarize the research activities conducted at the Advanced Materials Processing Laboratory at Northwestern University in the area of sheet metal forming. An overview of our approach towards the system will be given followed by a summary of individual projects in the areas of failure prediction, design and control of a variable binder force, and the segmented die design with local adaptive controllers.

A Finite Element Based Die Design Algorithm for Sheet-Metal Forming on Reconfigurable Tools

Abstract: Tooling cost is a major contributor to the total cost of small-lot production of sheet metal components. Within the framework of an academic/industrial/government partnership devoted to the development of a reconfigurable tool for stretch forming, we have implemented a Finite Element-based procedure to determine optimal die shape. In the reconfigurable forming tool (Hardt, D. E. et al., 1993, A CAD Driven Flexible Forming System for Three-Dimensional Sheet Metal Parts, Sheet Metal and Stamping Symp., Int. Congress and Exp., Detroit, MI, SAE Technical Paper Series 930282, pp. 69-76.), the die surface is created by the ends of an array of square pins, which can be individually repositioned by computer driven servo-mechanisms. An interpolating polymer layer is interposed between the part and the die surface to attain a smooth pressure distribution. The objective of the die design algorithm is to determine optimal positions for the pin array, which will result in the desired part shape. The proposed spring-forward' method was originally developed for matched-die forming (Karafillis, A. P., and Boyce, M. C., 1992, Tooling Design in Sheet Metal Forming using Springback Calculations, Int. J. Mech. Sci., Vol. 34, pp. 113-131.; Karafillis, A. P., and Boyce, M. C., 1996, Tooling And Binder Design for Sheet Metal Forming Processes Compensating Springback Error, Int. J. Tools Manufac., Vol. 36, pp. 503-526.) and it is here extended and adapted to the reconfigurable tool geometry and stretch forming loading conditions. An essential prerequisite to the implementation of the die design procedure is the availability of an accurate FE model of the entire forming operation. The particular nature of the discrete die and issues related to the behavior of the interpolating layer introduce additional challenges. We have first simulated the process using a model that reproduces, as closely as possible, the actual geometry of the discrete tool. In order to optimize the delicate balance between model accuracy and computational requirements, we have then used the information gathered from the detailed analyses to develop an equivalent die model. An automated algorithm to construct the equivalent die model based on the discrete tool geometry (pin-positions) is integrated with the spring-forward method, to generate an iterative die design procedure that can be easily interfaced with the reconfiguring tool. The success of the proposed procedure in selecting an optimal die configuration is confirmed by comparison with experimental results.

Method of making an electrical connector

Abstract: A method of making an electrical connector includes the steps of: a. stamping and forming a contact strip ( 10 ) and a number of contacts ( 12 ) on the contact strip; b. defining a recess ( 16 ) in a tail ( 14 ) of each contact; c. applying a first finish of nickel material on portions of the contact having the recesses followed by a second finish of tin-lead alloy material; d. injection molding an insulative housing ( 20 ) to the contacts; e. bending the tails outwardly; f. severing the contact strip from the contacts at the recesses.

Method and apparatus for welding

Abstract: The subject method pertains to a method and apparatus for welding. The subject invention can be utilized for welding very thin sections of stainless steel. The subject technique can incorporate a laser, such as a Nd:YAG, CO2, or diode laser. Furthermore, the laser may be a continuous wave (CW) or pulsed type. The subject invention can reduce or eliminate the need for expensive seam tracking or line following devices to compensate for tooling tolerances, stamping tolerances, and other effects leading to movement of the parts as they are rotated under a welding means. The subject invention can enable high quality symmetrical welds on thin sections of material, while reducing the attention required by a human operator. Furthermore, the method can be applied to other materials. Because of the nature of the beam delivery system, the spatial mode structure of the laser beam is no longer critical to the weld quality of the finished product. The method can be applied to weld the inner and outer diameters of welded bellows sections.

Principle and Simulation of Fixture Configuration Design for Sheet Metal Assembly with Laser Welding, Part 1: Finite-Element Modelling and a Prediction and Correction Method

Abstract: The quality of the stamping process has a direct effect on laser welded sheet metal assembly. The fixture plays an important role in the satisfactory metal fit-up that laser welding requires. The traditional “3-2-1” locating scheme will no longer suffice for the deformable laser sheet metal assembly process. Because of the often poor stamping quality, a complex die fixture has to be employed to meet the metal fit-up requirements. The die fixture corresponds to an “infinite-2-1” locating scheme where the tooling cost is very high and yet lacks flexibility. This limits the application of laser welding. In this paper, a new locating scheme with both total locating and direct locating for welds is proposed. A total locating scheme is used to locate the overall assembly, and a direct locating scheme is used to locate the weld location, which is critical for ensuring correct metal fit-up. A finite-element model and a prediction and correction method for the direct locator configuration are developed in this paper. A case study is used to show that the proposed method is effective for sheet metal assembly for laser welding.

Modeling and Optimization of End Effector Layout for Handling Compliant Sheet Metal Parts

Abstract: Material handling of compliant parts is one of the most critical and underresearched problems in the sheet metal stamping industry. The fundamental shortcoming of currently studied material handling systems for sheet metal stamping is the lack of analysis of its impact on part dimensional quality and production throughput. This paper addresses this problem by development of a generic methodology for modeling and optimization of part holding end-effector layout in order to minimize part dimensional deformation during handling operations. The methodology extends the design of ‘‘N-2-1’’ fixturing layout by adding part movability conditions. It considers part CAD model, handling direction and motion kinematic parameters to determine the best end effector layout. This methodology is realized by integrating FEM part and loading modeling with the optimization algorithm. It can be implemented into the design stage of a stamping line so that the trial and error process, which is current industrial practice, can be greatly shortened and the production throughput increased. Experimental results verify the proposed part holding end-effector layout methodology.

Stamping foils for use in making printed circuits and radio frequency antennas

Abstract: A stamping foil includes a carrier film, a layer of heat activated adhesive, a layer of vacuum deposited copper, a substrate and a release layer. The layers are activated by heat and pressure by a die which causes the layers to delaminate from the carrier film and adhere to a surface of a substrate in a predetermined electrically conductive pattern. The release layer releasably couples the layer of vacuum deposited copper to the substrate.

Method and apparatus for clinching metal sheets

Abstract: A method and apparatus for clinching metal sheets is disclosed. The apparatus includes a punch assembly for stamping indentations into stacked metal sheets and a die assembly for assisting in supporting the sheets during stamping of the indentations and for assisting in forming the indentations. The punch assembly, the die assembly or both in combination provide energy to at least a portion of the metal sheets prior to stamping. In turn, the energy elevates the temperature of the portion of the sheets such that the indentations can be more effectively formed in the portion and such that the sheets are fastened to each other with greater strength.

Method of manufacturing formed component having very high mechanical property by standing from covered rolled steel sheet, in particular, covered hot-rolled steel strip

Abstract: PROBLEM TO BE SOLVED: To provide a method of manufacturing a formed component having a very high mechanical properties by stamping a rolled steel sheet covered by metal or a metal alloy for reliably protecting the surface of the steel sheet and steel inside thereof, in particular, a hot rolled steel strip. SOLUTION: This manufacturing method comprises a step of cutting the steel sheet to obtain a steel sheet blank, a step of forming the component by stamping the steel sheet blank, a step of covering the surface of the steel sheet by an intermetallic compound capable of ensuring the protection against the corrosion and the decarburization of steel and ensuring the lubricating function, and a step of cutting and removing an excess portion of the steel sheet necessary for the stamping. COPYRIGHT: (C)2001,JPO

Preview display device as well as form treating equipment and method for the same

Abstract: PROBLEM TO BE SOLVED: To display and adjust the ranges of the respective images of plural forms and the positions of post treatment at the respective forms in an easily understandable manner. SOLUTION: This form treatment equipment subjects the printed forms to post treatment, such as stapling, punching and stamping. The form treatment equipment described above displays the preview images of one sheet each of the printed forms in printing plural sheets. Further, the form treatment equipment displays the positions of the post treatment, such as stapling, punching and stamping, applied to the respective forms within the preview images, presents the same to a user and adjusts the positions of the post treatment according to the operation, etc., of the user in a manner that the post treatment does not affect the printed images.

Use of self-adhesive materials having anisotropic properties for producing stamping products

Abstract: The invention relates to the use of a self-adhesive material having anisotropic properties for producing stamping products.