JPH09292987A - Method for writing program in bare-chip type prom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily write a program in a bare-chip type PROM without complicating a device on a substrate. SOLUTION: The bare-chip type PROM 3 is mounted to the substrate 1, and the PROM is connected to a wire pattern 2 on the substrate 1 by wire bonding. After this, a connector pin 8 connected to a PROM writer 6 is inserted to the through hole 5 of the substrate 1 to write the program by means of the PROM writer through the through hole 5. After the completion of the program, another molecular part 4 is mounted to the substrate 1.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a bare chip PR.
More particularly, it relates to a method for writing a program in a bare chip PROM mounted on a substrate by wire bonding while the bare chip PROM is mounted on the substrate.

[0002]

2. Description of the Related Art When prototyping and developing a device with a built-in computer, generally, a mask ROM is used instead of the PRO
M is used, and the trial program is written in this PROM by the PROM writer.

When writing a program in this PROM, the lead pin of the PROM is inserted into the connector of the PROM writer, and in that state, the program is written by the PROM writer. However, in the packaged type PROM, the lead pin of the PROM can be inserted into the connector of the PROM writer in this way, but in the unpackaged bare chip type PROM, there is no lead pin. As such, it is not possible to write a program easily.

Therefore, as a program writing method capable of coping with this, a method as disclosed in, for example, Japanese Patent Laid-Open No. 6-52332 has been conventionally proposed.

In this program writing method, P
A plurality of terminals dedicated to writing to the ROM are provided, and a PROM writing processing program is stored in advance in another ROM to be mounted. After the PROM is mounted on the board together with other electronic components, the PROM is stored in the other ROM. At the same time as starting the writing processing program, the writing program of the PROM is input from the dedicated terminal, and thereby the program is written to the PROM.

[0006]

However, in the above-described conventional PROM program writing method, a plurality of terminals dedicated to PROM writing must be provided on the substrate, and the write processing program is stored in another ROM.
Since it has to be stored in the memory, the number of unnecessary parts and occupied memory area after writing the PROM increases, and as a result, the device on the substrate becomes complicated and the manufacturing cost increases.

Therefore, the present invention provides a program writing method for a bare-chip PROM which allows a program to be easily written in the bare-chip PROM without complicating the device on the substrate and thereby reducing the manufacturing cost. It is what

[0008]

As a means for solving the above problems, the present invention mounts a bare chip type PROM at a predetermined position of a substrate having through holes on a wiring pattern, and uses this bare chip type PROM as a substrate. After connecting the wiring pattern to the wiring pattern by wire bonding, insert the connector pin connected to the PROM writer into the through hole of the substrate, and through the through hole, PR
The program is written by the OM writer, and after the writing of the program is completed, other electronic components are mounted on the board. Since the other electronic components are mounted on the substrate after writing the program, the high voltage at the time of writing the program is not applied to the other electronic components. If you do this,
It is not necessary to provide a special terminal dedicated to PROM writing on the substrate or to store the writing processing program in another mounting ROM.

Further, a plurality of connector pins to be inserted into the through holes are supported by a holder in an arrangement corresponding to the through holes on the board, and all connector pins are simultaneously inserted through the holder into a predetermined through hole. Is also good. In such a case, it becomes easy to insert the connector pin into the predetermined through hole.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, 1 is a substrate on which a wiring pattern 2 is printed, 3 is a bare chip PROM mounted on this substrate 1, and 4 is another electronic component mounted on the substrate 1. . Although a plurality of electronic components are mounted on the substrate 1 in addition to the PROM 3, only one electronic component 4 is shown in the drawing, and other electronic components are not shown. The PROM 3 is of a type capable of writing a program only once by application of a high voltage such as a junction breakdown type, and is connected to the wiring pattern 2 of the substrate 1 by wire bonding. ing. Further, through holes 5 having conductors attached to the inner peripheral surface thereof are provided at appropriate positions on the wiring pattern 2 of the substrate 1, so that electronic parts can be soldered to these through holes 5 later. Has become.

Reference numeral 6 is a well-known PROM writer, and a plurality of output pin holes 7 are provided on the upper surface of the PROM writer 6, and the bases of the connector pins 8 are fitted into the pin holes 7. It is like this. The tip of each connector pin 8 is sharpened like a needle,
The connector pin 8 is inserted into a predetermined through hole 5 that is electrically connected to each wire bonding portion 9, and the connector pin 8 is held by the holder 10 so that the tip ends of the connector pins 8 face the corresponding through holes 5 at the same time.

Now, a procedure for writing a program in the bare chip PROM 3 will be described with reference to the flowchart of FIG.

First, the bare chip type PROM 3 is
The electronic component 4 is mounted at a predetermined position on the substrate 1 (S1), and in that state, the PROM 3 is connected to the wiring pattern 2 by wire bonding (S2).

Next, the base portions of the connector pins 8 held by the holder 10 are fitted into the pin holes 7 of the PROM writer 6, and in this state, the tip portions of all the connector pins 8 are simultaneously inserted into the predetermined through holes 5. (S3).

Subsequently, in this state, the PROM writer 6 is operated, the write signal from the PROM writer 6 is input to the PROM through the through hole 5, and the PROM is written.
A predetermined program is written to (S4).

After the writing of this program is completed, the other electronic component 4 is mounted on the board 1.

In this program writing method, as described above, the PROM writer 6 uses the through-hole 5 to perform the P writing without providing the substrate 1 with the special write-only terminal or the like.
Since the ROM 3 is written, the program writing itself is simple and the device on the substrate 1 is simplified, so that the manufacturing cost can be reduced.

Further, since the writing of the PROM is performed before mounting other electronic components on the substrate 1, the electronic component 4 is destroyed even when a high voltage flows on the wiring pattern 2 at the time of writing the program. There is no problem.

[0020]

As described above, according to the present invention, a bare chip type PROM is mounted at a predetermined position of a substrate having through holes on a wiring pattern, and the bare chip type PROM is connected to the wiring pattern of the substrate by wire bonding. Since the connector pin connected to the PROM writer is inserted into the through hole of the board, the program is written by the PROM writer through the through hole, and other electronic parts are mounted on the board after the writing of the program is completed. It is not necessary to provide a special terminal dedicated to PROM writing on the substrate or to store the writing processing program in another mounting ROM, and as a result, the bare chip PROM can be easily implemented without complicating the device on the substrate. Can write programs. Therefore, according to the present invention, the manufacturing cost can be reduced more reliably than the conventional one.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a flowchart showing the same embodiment.

[Explanation of symbols]

 1 ... Board, 2 ... Wiring pattern, 3 ... Bare chip type PROM, 4 ... Electronic component, 5 ... Through hole, 6 ... PROM writer, 8 ... Connector pin, 10 ... Holder.

Claims (2)

[Claims] 1. A bare chip PROM is mounted at a predetermined position on a substrate having a through hole on a wiring pattern, the bare chip PROM is connected to the wiring pattern of the substrate by wire bonding, and then the through hole of the substrate is Program writing of a bare chip type PROM characterized in that a connector pin connected to a PROM writer is inserted, a program is written by the PROM writer through this through hole, and other electronic parts are mounted on a substrate after the writing of this program is completed. Method. 2. A plurality of connector pins to be inserted into the through holes are supported by a holder in an arrangement corresponding to the through holes on the substrate, and all connector pins are simultaneously inserted into a predetermined through hole through the holder. The method for writing a program in a bare chip PROM according to claim 1.