The invention relates to a method for testing a chip with a package, and for mounting the package on a board, wherein the adjacent connecting pins of the package are in an inline arrangement.
In order to keep the dimensions small for the package of a chip with multiple connecting pins, for example, 88 pins, the connecting pins are arranged in line as closely as possible. However, a minimum spacing must still be maintained since the space between associated holes on a board for insertion of the connecting pins may not be arbitrarily reduced. As the spacing of the holes and conducting lines on the board becomes closer, the process of fabricating a board becomes more complex and expensive. In addition, there is the risk that close spacing of the holes on the board will cause the connecting pins to short out during the soldering process.
One means of increasing hole spacing on the board is to configure the connecting pins of the package by bending some of the connecting pins or, for example, by inwardly offsetting every second connecting pin. However, the advantage of greater hole spacing on the board is counteracted by the disadvantages of requiring a special test socket to test the chips and requiring an expensive packaging means. Specifically, the packaging means must be designed such that the connecting pins are not bent out of their precise alignment.
The goal of the invention is therefore to design a method for testing a chip with a package, and for mounting the package on a board in such a way that simple and inexpensively produced test sockets are sufficient for testing, and similarly simple and inexpensively produced packaging means are sufficient for packaging, while at the same time achieving an offset arrangement for the connecting pins.
The invention achieves this goal using the features listed in claim 1 by inserting the package with its inline connecting pins into a test socket for testing and by bending inward at least one connecting pin using a bending tool immediately before insertion of the connecting pins of the package into the holes of the board, in order to achieve an offset arrangement of the connecting pins.
In the method according to the invention, the package is fabricated with inline connecting pins—individuals skilled in the art frequently use the expression “dual inline”—and the chip is tested in this state. To this end, the chip is inserted into a test socket. The first advantage here is that inexpensively produced test sockets may be utilized to test the chips. The second advantage is that even inexpensive packaging means are sufficient for storing and transporting the chips. Additionally, in the method according to the invention, at least one connecting pin, preferably every second connecting pin, is bent inward by a bending tool immediately before insertion of the connecting pins of the package into the board in order to form an offset arrangement of the connecting pins. The invention thus combines the advantages of a package in which its connecting pins are in an inline arrangement with those of a package in which its connecting pins are in an offset arrangement.
Electrical testing of the chip may thus be of a simple design since inexpensively produced test sockets are sufficient for the task. In addition, standard packaging means may be employed to package the package. Subsequent alignment of the connecting pins is simplified since the connecting pins are not bent into the offset arrangement until immediately before insertion into the board, rather than at the fabrication stage of the package.
The invention will be described and explained in more detail based on the figures:
The package 2 fabricated with inline connecting pins 1 is inserted into a test socket 3 in order to test the chip. Any rework which might be required on package 2 or the chip is performed. Package 2 is then packaged in a packaging means such as a guide brace 4. Immediately before package 2 is mounted on a board 5, every second connecting pin 12, for example, is bent inward by bending tool 6, while the remaining connecting pins 11 are left unmodified. Connecting pins 11 and 12 are now inserted into the holes 7 of board 5, preferably, by bending tool 6.
The spacing between the vertical pins on the package is 19.05 mm. Second connecting pins 12 are bent 0.4 mm inward from the vertical, while remaining connecting pins 11 are bent 0.87 mm outward.
It is especially advantageous to arrange the connecting pins on the package symmetrically relative to the longitudinal center axis and transverse center axis of the package since this symmetrical arrangement allows for the use of a symmetrical bending tool. It is then irrelevant how the bending tool is placed on the package. It is impossible to bend the connecting pins incorrectly by attaching the bending tool with the improper orientation.
The method according to the invention permits the use of packaging means suitable for the standard PSDIP package. No special packaging means are required.
While the above figures describe an approach in which every second connecting pin is bent inward once,
List of reference notations
Number | Date | Country | Kind |
---|---|---|---|
101 36 578.0 | Jul 2001 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP02/08369 | 7/26/2002 | WO |