JPH0379868B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a multi-chip package in which a plurality of electronic functional elements are mounted at the semiconductor chip level on a common support base constituting a high-density wiring board.

In recent years, there has been an increasing demand for electronic components to be smaller and more reliable, and the conventional mounting method of mounting semiconductor elements molded in plastic or ceramic on a printed circuit board is no longer able to meet the demands for miniaturization. It is coming. For this purpose, a semiconductor element, which is an electronic functional element, is placed in the form of a chip on a high-density multilayer wiring board made of ceramic, etc., which is a single supporting substrate, using a flip-chip method, a beam lead method, a film carrier method, a chip-and-wire method, etc. A so-called multi-chip packaging technology has been developed in which the entire chip is hermetically sealed.

In such multichip packages, as the overall circuit configuration approaches the system level, it becomes impossible to function unless a voltage higher than the maximum rated voltage of other electronic functional elements, such as PROM or FPROM, is applied inside the multichip package. Increasingly, there are electronic functional elements with high withstand voltages that cannot be maintained. In this case, if all the electronic functional elements are mounted on a common support substrate and simply interconnected, then when a high voltage is applied to retain the functionality of the high-voltage electronic functional elements, other low-voltage electronic functional elements A problem arises in that functional elements are destroyed.

Therefore, in the past, as shown in FIG.
is in the form of a semiconductor chip and is supported and fixed on a support base, such as a high-density multilayer wiring board 12 made of ceramic, to form a multi-chip package, and the high voltage electronic functional element A is not at the semiconductor chip level, but in a conventional plastic or ceramic molded package. For example, a mounting method has been adopted in which the IC is supported and fixed directly on the printed wiring board 11 or via an IC socket 16 or the like. However, this method was not fully satisfactory in terms of circuit miniaturization. Furthermore, since the wiring length between the high-withstand voltage electronic functional element group A 14 and the low-withstand voltage electronic functional element group B 15 becomes long, there are also problems in terms of induced noise and circuit operation speed.

The present invention was made in consideration of these circumstances, and its purpose is to mount both high-withstand voltage and low-withstand voltage electronic functional elements in the form of a chip on a common support base. The object of the present invention is to provide a multi-chip package that can reduce the size of the circuit and increase the speed of the circuit.

The present invention provides a method for connecting a high withstand voltage electronic function element to a low withstand voltage electronic function in a transmission line which is wired sequentially from an input/output terminal disposed on a support base to a high withstand voltage and a low withstand voltage electronic function element. A dividing part is provided in the part that reaches the element, and the high withstanding voltage electronic functional element is electrically separated from the high withstanding voltage electronic functional element by the dividing part, and a predetermined voltage is applied to the high withstanding voltage electronic functional element. After applying a voltage to have a predetermined function, the divided portion is short-circuited to electrically connect the high-withstand voltage electronic functional element and the low-withstand voltage electronic functional element, thereby forming the entire multichip package. It is characterized by having the required circuit functions.

Therefore, according to the present invention, each of these electronic functional elements can be operated without the problem of destruction of the low withstand voltage electronic functional elements due to the applied voltage to allow the high withstand voltage electronic functional elements to retain their functions. Since they can be mounted on a common support base, the circuit can be made more compact, and by shortening the mutual wiring length, it is possible to increase the speed of operation and reduce induced noise.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows the structure of a multi-chip package according to an embodiment of the present invention. A support base 21 constitutes a high-density multilayer wiring board made of, for example, ceramic. 22 is a sealing cap, and 23 is an input/output pin. Further, 24 is a die bonding pad formed to mount the electronic functional elements A, B on the supporting base 21, and 25 is a die bonding pad formed to mount the electronic functional elements A, B and the wiring on the supporting base 21 using, for example, Au wire or Aluminum wire. A wire bonding pad 26 formed to be connected by wire bonding with a wire or the like is a conductive pattern for bonding the sealing cap 22.

Reference numeral 27a denotes a pair of adjacent terminals constituting a disconnection section for temporarily disconnecting the wiring connecting a high-voltage electronic functional element A such as PROM or EPROM to another low-voltage electronic functional element B. This terminal pair 27a is formed inside the sealing cap 22 on the support base 21 as part of the wiring pattern. Also, 27b is a similar terminal pair, but unlike 27a, it is formed outside the sealing cap 22 on the periphery of the support base 21 as part of the wiring pattern. In such a structure, A and B are connected to the input/output terminal 28a or 28b.
A predetermined voltage (write voltage in the case of PROM, EPROM, etc.) is applied to the high-voltage electronic functional element A through the transmission line sequentially wired to the element A, and the element A is processed to maintain its function (memory function). Thereafter, the terminal pair 27a or 27b is short-circuited and A and B are electrically coupled to provide the required circuit function as a whole. In this way, the low withstand voltage electronic functional element B will be protected from the application of a voltage exceeding its rated voltage and will not be destroyed. The terminal pair 27a, 27b can be short-circuited by, for example, wire bonding using Au wire or Al wire, solder bridge using solder balls, conductive epoxy, or the like.

27c to 27e show other configuration examples of the dividing portion. Reference numeral 27c is a switch functional element supported and fixed on the support base 21, and when a predetermined voltage is applied to the high withstand voltage electronic functional element A, it is turned off and the low withstand voltage electronic functional element B is switched to its rated value. This is to prevent a voltage higher than the voltage from being applied. Also, instead of this switch function element 27c, a simple relay function element 27 from which the switch function has been removed.
d may also be used. Next, 27e is the input/output terminal 28
When a high voltage is input from c to the high voltage electronic functional element A to have the function, that voltage is detected and the high voltage is applied to the high voltage electronic functional element A.
When high voltage is not input to the input/output terminal 28c, the wiring 29 and the wiring 30 are automatically connected electrically, and the wiring 29 and 30 are automatically connected to the disconnected state according to the voltage detection result. and a short circuit state. The group C of electronic functional elements having this voltage detection function is supported and fixed on the support base 21 at the semiconductor chip level similarly to A and B. However, in this case, the values of the withstand voltage and input/output current capacity of the electronic functional element C, and the voltage applied to the high withstand voltage electronic functional element A via the electronic functional element C, do not drop below a predetermined voltage. It is necessary to take into consideration the following factors when designing.

Note that the present invention is not limited to the above-mentioned embodiments; for example, A and B in FIG. , may be a high withstand voltage electronic functional element group, or may be a low withstand voltage electronic functional element group. Furthermore, although each wiring is shown as a single line in the figure, this often represents a plurality of wirings, and in this case it must be considered that a terminal pair is also provided for each wiring. Although FIG. 2 mainly shows a multi-chip package using the chip-and-wire method as an example, the present invention is not limited to this.
It may also be a multi-chip package using a film carrier method, a beam lead method, or the like.

As explained above, according to the present invention, PROM,
It becomes possible to package system-level circuit functions, such as EPROM, etc., on a common support base in multi-chip packaging, making it possible to fully meet the demands for smaller and faster circuits.

[Brief explanation of drawings]

FIG. 1 is a partially sectional side view for explaining a conventional technique in which only low-voltage electronic functional elements are packaged into a multichip package, and FIGS. 2a and 2b show a multichip package according to an embodiment of the present invention. FIG. 2 is a plan view and a partially sectional side view. 21... Support base, 27a, 27b... Terminal pair forming the dividing section, 27c... Switch functional element forming the dividing section, 27d... Relay functional element forming the dividing section, 27e... forming the dividing section. Electronic functional element, A... High voltage electronic functional element, B
...Low withstand voltage electronic functional elements.

Claims (1)

[Scope of Claims] 1. A multi-chip package in which a plurality of electronic functional elements are mounted in the form of chips on a common support base and are interconnected to provide a required circuit function, and A multi-pack package in which some of the electronic functional elements are high-voltage electronic functional elements that possess a predetermined function by applying a predetermined voltage higher than the maximum rated voltage of other low-voltage electronic functional elements. , from the high withstand voltage electronic functional element to the low withstand voltage functional element in the transmission path, which is wired sequentially from the input/output terminal arranged on the support base to the high withstand voltage and low withstand voltage electronic functional element. A dividing portion is provided in the portion leading to the high withstand voltage electronic functional element, and the high withstand voltage electronic functional element is electrically separated from the low withstand voltage electronic functional element by the dividing portion, and a prescribed voltage is applied to the high withstand voltage electronic functional element. is applied to have a predetermined function, and then the divided portion is short-circuited to electrically connect the high withstand voltage electronic functional element and the low withstand voltage electronic functional element, thereby achieving the required circuit function as a whole. A multi-chip package characterized by being configured to have. 2. The multi-chip package according to claim 1, wherein the dividing portion is a pair of adjacent terminals formed as part of a wiring pattern on the support substrate. 3. The multi-chip package according to claim 1, wherein the dividing portion is a switch function element or a relay function element supported and fixed on the support base. 4. A patent characterized in that the dividing section is constituted by an electronic functional element that has the function of detecting the voltage applied from the input/output terminal on the support base and automatically switching between the disconnected state and the short-circuited state. Claim 1
Multi-chip package as described in section. 5 High voltage withstand electronic functional elements are PROM or
The multi-chip package according to claim 1, which is an EPROM.