Low cost pin and tab assembly for ceramic and glass substrates

#1. Field of the Invention

#The present invention generally relates to integrated circuit structures and manufacturing methods and, more particularly, to structures having at least one chip and connection pins bonded to opposite sides of a substrate.

#2. Description of the Prior Art

#The foregoing and other objects, aspects and advantages will be better understood from the following detailed description of a preferred embodiment of the invention with reference to the drawings, in which:

#FIG. 1 is an isometric view of the organization of the invention including pin down (A) and pin up (B) views in exploded and assembled form, respectively,

#FIG. 2 is a sectional view at a location of a connection pin generally indicated by circle II in FIG. 1,

#Referring now to the drawings, and more particularly to FIG. 1, there are shown views A and B of the invention. In exploded, "pin down", view A, a substrate 1 is to be sandwiched between substrate holder 4 and a non-solder-wettable pin holder 7. As will be explained in further detail below, the pin holder also functions as a braze boat and is preferably a single part performing both functions. The part or parts comprising the braze boat/pin holder will be referred to herein by the most immediately relevant function being performed by the part or parts. When assembled, substrate 1, substrate holder 4 and pin holder 7 are held together by a holder clip or clamp 8.

#Alignment of the substrate holder 4 and the pin holder 7 is preferably provided by the outer dimensions thereof, but could be provided in many other ways, such as with registration pins and the like. Alignment of the substrate 1 with the substrate holder 4 and, hence, with the pin holder 7, by adjustments 9, 12, preferably provided as screws 9 and threaded holes 12 in the substrate holder 4, arranged such that the screws 9 engage the edge of substrate 1. It is also preferable to provide a sufficient number of such adjustment arrangements that the substrate 1 may be positioned in two orthogonal directions as well as rotationally within the substrate holder 4 and be firmly retained therein, regardless of orientation, without imposing excess mechanical stress on substrate 1. Adjustment means 9, 12, may be manipulated to achieve correct positioning of the substrate 1 after the substrate holder 4 is assembled with pin holder 7 by observing registration marks, edges, or other features such as an input/output (I/O) pad on the surface of substrate 1 through one or more optical alignment holes 10.

#The pin holder or braze boat 7 functions, at this point, to hold and locate the connection pins 3 and solder preforms 3' which are inserted into countersunk holes 13 in the pin holder. The holes are preferably slightly larger than the bodies of the pins and the pins 3 are prevented from dropping through the pin holder 7 by the enlarged head of each pin. The countersunk portion of holes 13 is preferably shaped to receive the pin head such that the pin head, but not the solder preform 3' will be flush with the surface of pin holder 7.