JP2799073B2 - LSI Sonnet with built-in probe pins - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a socket for an LSI chip having a large number of input / output pins.

(Prior Art) With the high integration of LSI chips, the size of packages containing them and the number of pins are increasing. Recently used packages include a PGA (Pin Grid Array) type and a QFP (Quad Flat Pin) type. These packages enable LSIs with many pins to be mounted on a board at high density.

However, in the case of product development, it is necessary to conduct an operation test of the LSI while it is mounted on the board, but from this point of view, highly integrated LSIs have a pin There is a problem that it is difficult (or physically impossible) to apply probe pins.

Heretofore, this problem has been avoided by "pulling out the pins of the LSI to be observed to a location where the probe can be easily applied using a pattern on the substrate in advance." However, the ever-increasing number of pins has a new problem that a probe pattern cannot be drawn on a substrate due to a decrease in the pin interval, which is becoming difficult to realize.

(Problems to be Solved by the Invention) In view of the above-mentioned problems of the prior art, the present invention provides a multi-pin LSI.
The problem is to realize an LSI socket with built-in probe pins, which has the function of selecting the pins to be observed from a large number of pins and connecting them to the pins for probes in the LSI socket between the package and the board. It is an object of the present invention to facilitate the operation check of an LSI on a board by solving the problem.

[Configuration of the invention]

(Means for Solving the Problems) The LSI socket with a built-in probe pin of the present invention has an LSI pin connector hole corresponding to a multi-pin LSI package on the upper surface of the socket body, and electrically connects with these connector holes on the lower surface. It has a connected socket pin, and has a plurality of probe pins and the same number of selection signal input means as the probe pins on the upper surface of the socket body, and further receives an LSI pin signal through the LSI pin connector hole as an input, and The selection signal from the selection signal input means is used as the control signal input, and the LSI
And a probe pin selection circuit for selecting a signal corresponding to the selection signal from the signals of the pins as a probe signal and outputting the selected signal to the probe pins.

(Function) The LSI socket with built-in probe pins of the present invention is used by inserting an LSI pin into the LSI pin connector hole on the upper surface of the socket body and connecting the socket pin on the lower surface of the socket body to the board or a normal LSI socket on the board. I do. When a selection signal for selecting a signal of an LSI pin to be observed is input from the selection signal input means, this signal is input to a probe pin selection circuit as a control signal, and the probe pin selection circuit outputs a plurality of input LSI pin signals. The signal corresponding to the selection signal is selected as a probe signal from among the signals, and is output to the probe pin. Thus, in a state after mounting, a signal of a desired pin of the LSI can be pulled out to a probe pin which is easily applied to a probe and can be easily observed.

(Examples) Hereinafter, the present invention will be described in detail based on examples shown in the drawings.

1 and 2 show an LSI socket with built-in probe pins according to an embodiment of the present invention. Figure 1 LSI with built-in probe pin
The socket is an example in which the present invention is applied to a PGA type package. As shown in FIG. 1, the socket body (1)
An LSI pin connector hole (2) corresponding to a multi-pin LSI package is provided on the upper surface, and a socket pin (6) electrically connected to these connector holes (2) is provided on the lower surface. . A plurality of probe pins (4) are protruded from the upper surface of one overhang portion of the socket body (1) at a required interval. On the upper surface of the other protruding portion of the socket body (1), for example, dip switches (5) are provided as selection signal input means in the same number as the number of probe pins (4). Further, a probe pin selection circuit (3) is built in one protruding portion of the socket body (1). The probe pin selection circuit (3) is, for example, a logic circuit as shown in FIG. 2, which receives a signal of an LSI pin via an LSI pin connector hole (2) as an input and selects a selection signal from a dip switch (5). Is a control signal input. The output signal of the probe pin selection circuit (3) is connected to the probe pin (4).

As shown in FIG. 2, the probe pin selection circuit (3) is a circuit for selecting a probe signal from a plurality of LSI pin signals by a selection signal, and a plurality of sets are provided as necessary. The LSI pin signal is connected to all or some of the signal pins of the LSI. The selection signal has a sufficient number of bits to select one signal from a plurality of pin signals.

The LSI socket with a built-in probe pin of the embodiment of the present invention configured as described above inserts the LSI pin into the LSI pin connector hole (2) on the upper surface of the socket body (1), and the socket pin on the lower surface of the socket body (1) (6) is used by connecting to a board or a normal LSI socket on the board.

When a selection signal for selecting an LSI pin signal to be observed is input from the dip switch (5), this signal is input to the probe pin selection circuit (3) as a control signal, and the probe pin selection circuit (3) is input. There are multiple LS
A signal corresponding to the control signal is selected as a probe signal from the I pin signals, and is output to the probe pin (4).

As a result, an LSI with built-in probe pins according to one embodiment of the present invention
According to the socket, the signal of the pin to be observed can be extracted to the probe pin (4) from a large number of pin signals of the LSI after mounting, and the probe pin ( The signal to be observed can be checked by applying the probe to 4), and the operation of the LSI on the substrate can be easily confirmed. Further, by using the present socket via a normal socket, a test can be performed without adversely affecting the board after the test.

In the embodiment shown in FIG. 1, the selection signal is input from the DIP switch (5) fixed on the socket body (1), but an external input pin is used instead of the DIP switch (5). A selection signal input means may be provided so that the selection signal is taken in from the external input pin. The power for the probe pin selection circuit (3) can be shared with the LSI, or can be separately supplied from the outside. Further, the LSI socket with built-in probe pins is not limited to the shape shown in FIG.

〔The invention's effect〕

As described in detail above, according to the present invention, a plurality of probe pins and probe pin selection signal input means are provided on the upper surface of the socket main body, and a selection signal from the selection signal input means selects from among a large number of LSI pin signals. By implementing a probe pin built-in LSI socket with a built-in probe pin selection circuit that selects a signal corresponding to the selection signal as a probe signal and outputs it to the probe pin, in the state after mounting, a large number of LSI pin signals The signal of the pin you want to observe from inside can be extracted to the probe pin,
Tests required after mounting can be easily performed without incorporating a special probe circuit in the LSI itself. Further, by using the present socket via a normal socket, a test can be performed without adversely affecting the board after the test.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an LSI socket with built-in probe pins according to an embodiment of the present invention, and FIG. 2 is a circuit diagram showing a probe pin selection circuit built in the socket of FIG. 1 ... socket body, 2 ... LSI pin connector hole, 3 ...
... Probe pin selection circuit, 4 ... Probe pins, 5 ...
... dip switches, 6 ... socket pins.

Claims (1)

(57) [Claims] An upper surface of a socket body has an LSI pin connector hole corresponding to a multi-pin LSI package, a lower surface has socket pins electrically connected to the connector holes, and a plurality of socket pins are provided on an upper surface of the socket body. A probe pin and a probe pin selection signal input means, and an LSI pin signal through the LSI pin connector hole, and a selection signal from the selection signal input means as a control signal input to an LSI pin signal. A probe pin built-in LSI socket in which a probe pin selection circuit for selecting a signal corresponding to a selection signal as a probe signal from among the above and outputting the selected signal to the probe pin is built in the socket body.