JP2008166605A - Multi-chip module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the decline of reliability by eliminating adverse influence by heat even for a multi-chip module for which circuit boards arranged in two or more stages are connected and fixed so as to be clamped by terminals for external connection. <P>SOLUTION: The circuit boards 3 where a plurality of semiconductor chips 5 is mounted are laminated and disposed in two or more stages, and both ends of the respective circuit boards 3 are connected and held by being clamped by the recessed parts 9a of a clip terminal 9. A notched part 9b is provided between the recessed parts 9a of the clip terminal 9, the deformation (warp) caused by heat of the circuit boards 3 is absorbed by the notched part 9b and influence onto the other circuit boards 3 is eliminated. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a multichip module including a plurality of semiconductor chips which are electronic components.

  2. Description of the Related Art Conventionally, multi-chip modules having a configuration in which semiconductor chips are mounted on a circuit board with a small capacity and high density have been developed for use in particularly small electronic devices.

In recent years, in order to cope with an increase in the number of semiconductor chips, there has been proposed a semiconductor chip mounted on both sides of a circuit board in which two circuit boards are stacked and bonded in order to cope with an increase in the number of semiconductor chips (for example, the following). Patent Document 1).
JP-A-5-291493

  By the way, the above-described conventional multichip module fixes both ends of a two-layer circuit board so as to be sandwiched between terminals for external connection, and at the same time performs electrical connection with the outside.

  However, in such a multi-chip module, when the module is required to have a higher density and the two-layer circuit board is configured to be stacked in a plurality of stages at predetermined intervals, the external connection terminal described above is used. Thus, if each circuit board is sandwiched, when the circuit board is warped by heat, stress acts on the external connection terminals sandwiching the circuit board and adversely affects other circuit boards. The stress acts on the joint between the affected circuit board and the semiconductor chip mounted on the circuit board, leading to a decrease in reliability.

  Therefore, the present invention eliminates adverse effects due to heat and prevents a decrease in reliability even in a multichip module in which circuit boards arranged in a plurality of stages are connected and fixed so as to be sandwiched between terminals for external connection. The purpose is that.

  The present invention absorbs the deformation due to the warp generated in the circuit board due to heat by the notch part between the pinching parts of the terminals for external connection, eliminates the influence on the other circuit board, It is possible to prevent stress from being applied to the joint portion with the semiconductor chip mounted on the other circuit board and to prevent a decrease in reliability.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a front sectional view of a multichip module 1 according to a first embodiment of the present invention. In this multichip module 1, a plurality of circuit boards 3 (3a, 3b, 3c) (three in this case) are laminated at a predetermined interval, and on these circuit boards 3, electronic components are arranged. A plurality of semiconductor chips 5 are respectively mounted. The mounted semiconductor chip 5 is connected to the circuit board 3 by wire bonding 7.

  The left and right ends of each circuit board 3 in FIG. 1 are fixed by elastically deformable clip terminals 9 which are terminals for external connection. The clip terminal 9 is entirely composed of a conductive member, or the surface thereof is plated with a conductive metal member, and becomes a power supply terminal, a GND terminal, or a signal terminal of the semiconductor chip 5 on the circuit board 3. .

  As shown in the plan view schematically shown in FIG. 2 (a), such a clip terminal 9 may have a structure in which one long one is provided along the left and right side edges of the circuit board 3 in FIG. Alternatively, as shown in FIG. 2B, a plurality (two in this case) may be provided along the side edges of the left and right ends of the circuit board 3 in FIG.

  The above-described clip terminal 9 includes a concave portion 9a serving as a clamping portion that fixes each circuit board 3 so as to sandwich each circuit board 3, and both ends of the circuit board 3 are inserted into the concave portion 9a. Connect and fix with conductive adhesive. Thereby, the clip terminal 9 is in a state of mechanically holding and fixing the circuit board 3 and being electrically connected to the conductive portion on the circuit board 3.

  In the state where both ends of the circuit board 3 are inserted into the recesses 9a of the clip terminals 9, a gap 11 is provided between the edge of the circuit board 3 and the bottom of the recess 9a.

  Between the recesses 9a of the clip terminal 9 into which each circuit board 3 is inserted, a notch 9b having a depth substantially the same as the recess 9a and having a narrower vertical width in FIG. 1 than the recess 9a is provided. Yes.

  The clip terminal 9 is provided with a pin portion 9d extending downward from the lower outer side in FIG. 1 of the substrate holding portion 9c having the recess 9a and the notch portion 9b, and the pin portion 9d is connected and fixed to the mother substrate 13, for example. .

  Each circuit board 3 described above is covered with a resin cover 15 together with the substrate holding part 9c of the clip terminal 9 and a part of the pin part 9d on the board holding part 9c side. The resin cover 15 is composed of an upper cover 15a and a lower cover 15b. The covers 15a and 15b are covered with the circuit boards 3 held by the clip terminals 9 from above and below. The joint ends of the covers 15a and 15b are fixed with an adhesive or the like. At this time, the lower cover 15b is provided with a through hole 15c into which the pin portion 9d is inserted.

  In the multichip module 1 configured as described above, for example, when one of the circuit boards 3a is warped and deformed by heat generated by the semiconductor chip 5, for example, the stress due to the deformation acts on the clip terminal 9. However, this stress is absorbed by the notch 9b provided between the recesses 9a.

  Specifically, the clip terminal 9 is deformed by the warp of the circuit board 3a so that the portion 9e between the recess 9a into which the end of the circuit board 3a is inserted and the notch 9b is deformed to the notch 9b side. 9b is deformed so that the width in the vertical direction becomes narrower in FIG.

  As a result, the clip terminal 9 is prevented from being deformed in the vicinity of the other circuit boards 3b and 3c, particularly the recess 9b holding the circuit board 3b adjacent to the circuit board 3a in which the warp is generated, The deformation of the circuit board 3c can be prevented. By preventing deformation of the circuit boards 3b and 3c, it is possible to avoid applying stress to the joint between the circuit boards 3b and 3c and the semiconductor chip 5 mounted on the circuit boards 3b and 3c, thereby reducing reliability. Can be prevented.

  In other words, in the present embodiment, the influence of the warped circuit board on other circuit boards can be eliminated, and the reliability of the multichip module 1 having a higher density can be improved.

  FIG. 3 is a front sectional view of a multichip module 1A according to the second embodiment of the present invention. In this multi-chip module 1A, the circuit board 3 is integrated by bonding the surfaces on which the semiconductor chip 5 is not mounted by wire bonding 7, and the integrated two circuit board pairs 3A are connected to the clip terminals 9A. It is clamped and fixed by the recessed part 9a which is a clamping part.

  Other configurations are the same as those of the first embodiment shown in FIG. 1, and the same components are denoted by the same reference numerals.

  Also in the second embodiment, when a warp occurs in one circuit board pair 3A due to the heat generated by the semiconductor chip 5, for example, the stress due to the warp acts on the clip terminal 9, but this stress is a concave portion. 9a absorbs the notch 9b provided between each other, so that the influence on the other circuit board 3A is eliminated, and the reliability of the multichip module 1A having a higher density than that of the first embodiment of FIG. Can be increased.

It is front sectional drawing of the multichip module concerning the 1st Embodiment of this invention. FIG. 2 is a schematic plan view of clip terminals in the multichip module of FIG. 1. It is front sectional drawing of the multichip module concerning the 2nd Embodiment of this invention.

Explanation of symbols

3 Circuit board 5 Semiconductor chip (electronic component)
9 Clip terminal (terminal for external connection)
9a Recessed part of clip terminal (clamping part)
9b Notch in clip terminal

Claims (1)

  A plurality of circuit boards on which electronic components are mounted are stacked at a predetermined interval, and both ends of each circuit board are respectively clamped by clamping parts provided on the terminals for external connection, and the clamping part of the terminals for external connection A multi-chip module characterized in that a notch is provided between each other.

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