DVS 2811

Abstract

Scope: Scope, preliminary remarks, layout The purpose of this technical bulletin – a new edition of Technical Bulletin DVS 2811 – remains the same: to characterise the most common mechanical testing and optical/visual inspection methods for wire bonded joints and to defi ne the uniform application of these methods. When the August 1996 version of Technical Bulletin DVS 2811 [1] was published, even then it diff ered clearly from international standards that have since been updated but scarcely modifi ed (MIL-Std-883, ASTM International [2, 3]) by having stricter assessment criteria (e.g. minimum admissible pulling forces). Because of this its use in industry extended beyond national borders and it became a kind of template for industrial qualifi cation measures. Now, it is not just the wire materials being processed that have changed over the years (new: Au alloys, Cu, Ag), but the wire diameters – that also allow fully automated bonding – have decreased in size (≤ 17.5 μm). In addition, the technical bulletin did not previously cover the testing of heavy wire or ribbon bonded joints. As well as simply describing the test methods and the apparatus and tools essential for the tests, this new edition of Technical Bulletin DVS 2811 also sets out reference values and examples for test results and characteristics that cover all common bonding techniques, materials and tests and therefore take account of the technological advances and improvements in quality gained particularly in the last few years. It therefore provides the user with the requisite know-how to assess the results of his tests, compare them with others if necessary, and draw the appropriate conclusions. Importantly, it also enables suppliers of semi-fi nished bonding products to classify their products during sampling or comparative tests. The layout of the present document is as follows: First of all, Chapter 2 contains a defi nition of basic terms. Chapter 3 describes the apparatus and tools essential for the tests, and the test conditions. Non-destructive test procedures are described separately in "Optical inspection" (Chapter 4), "Nondestructive pull test“ (Section 5.1), "Non-destructive shear test" (Section 6.1) and "Process-integrated monitoring" (Chapter 7). Destructive test procedures are set out in "Destructive pull test" (Section 5.2), "Destructive shear test"(Section 6.2) and "Other test and analysis methods" (Chapter 8). Further – sometimes less well-known – test methods, which are generally only used to determine special properties of the joints, are summarized in Chapter 8. Finally, reference values that take account of technological advances and improved quality in wire bonding are presented for the test results or characteristics of all test methods (Chapter 9). The test methods described concern bonded joints produced in electronic components using the following methods: • Thin wire bonding – Ball/wedge and wedge/wedge – Wire diameters 12-75 μm • Heavy wire bonding – Wedge/wedge – Wire diameters 75-500 μm • Thin ribbon bonding – Wedge/wedge – Ribbon widths ≤ 500 μm – Ribbon thicknesses ≤ 100 μm – Typical width: thickness ratio < 10 • Heavy ribbon bonding – Wedge/wedge – Ribbon widths ≥ 500 μm – Ribbon thicknesses ≥ 100 μm – Typical width: thickness ratio < 10 The data in the document also apply to repair bonds. All data in this document refer to the condition of the bond point in its initial state after the bonding process. Bond points that have been subjected to stress, e.g. load infl icted during life tests or product qualifi cation tests (e.g. thermal ageing, temperature shock, vibration), must be assessed individually depending on the load and the expected degradation mechanisms. The data set out in the document will provide useful guidance in this respect