JPH0662382U - Multi-chip module - Google Patents

Abstract

(57) [Abstract] [Purpose] In a multi-chip module, an electrical test can be properly performed even after mounting a circuit element, and a test time is shortened. [Structure] The IC chip (1
a, 1b, 1c, 1d), the wiring pattern of the wiring board (2) on which the a.
a, 7b) to separate the IC chips in a circuit manner, and to connect the connection pads (7a, 7a,
7b) is connected by a bonding wire (8) or the like,
Complete the circuit of the multi-chip module.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a multi-chip module, and more particularly to a technique for allowing each IC chip to be electrically separated so that an electrical test can be performed even after a circuit element such as an IC chip is mounted on a wiring board.

[0002]

[Prior art]

 In equipment that uses a large amount of semiconductor elements such as computers, the degree of integration of circuit elements such as IC chips is increased to reduce the wiring length between circuit elements as much as possible and reduce the conductor resistance of the wiring. It is necessary to reduce the delay, reduce the delay, improve the circuit performance, and reduce the size of the circuit.

As a technique for increasing the degree of integration of circuit elements such as IC chips, a hybrid IC technique is applied to form a circuit by directly mounting a plurality of bare IC chips on a wiring board to form a circuit. There is a module. A multi-chip module is a die-bonded circuit element such as a plurality of bare IC chips that is directly die-bonded to a laminated wiring board in which a wiring pattern is formed by a conductor member such as Cu on a substrate such as glass epoxy or ceramic, and each electrode of the IC chip is And a wiring pattern are connected by wire bonding to efficiently connect a plurality of IC chips to each other on one substrate to form a circuit. In the multi-chip module, the bare IC chip is mounted directly on the wiring board to form a circuit, so the external terminals and soldering space required when mounting individual semiconductor components, each of which has an IC chip sealed in the package, on the printed circuit board Can be saved, and the wiring length of each IC chip can be shortened. Therefore, the mounting area of the circuit element can be reduced, and the loss and delay due to the wiring can be reduced to enable the module to operate at high speed and efficiently.

In order to improve the reliability as a component of a multi-chip module and to improve the yield, it is the first to use a bare IC chip whose quality is guaranteed. However, a bare IC chip is die-bonded to form a bare IC chip. At the stage where the bonding pad of the IC chip and the second pad of the wiring pattern are connected by wire bonding, each IC is tested in order to test the connection state of the bonding wire and the effect of thermal shock during die bonding of the IC chip. Electrical tests are performed on each wiring of the chip.

Conventionally, in this electrical test, a plurality of IC chips are interconnected by a wiring pattern to form a circuit of a multi-chip module, and a probe of a tester is used as an external output terminal of the multi-chip module or its external terminal. This was done by contacting the wiring that was connected to the output terminal in a circuit manner.

[0006]

[Problems to be solved by the device]

 However, in such a conventional multi-chip module, when testing each circuit element, etc., the circuit element is mounted on the substrate and the electrical test is performed in the state where the plurality of circuit elements are connected by the wiring pattern. Even if the tester's probe was brought into contact with the external output terminals of the multi-chip module and inspected, multiple circuit elements interacted with each other, and as a result, appropriate inspection results were often not obtained. Also, among the wiring patterns, those connected to the lines that are particularly affected by the delay have an influence on the capacitance, etc., and complex parameter adjustment was necessary for the electrical test.

Therefore, an object of the present invention is to check the characteristics of each IC chip, the connection state of bonding wires, etc. even when the circuit elements are mounted and the wiring connection is completed during the manufacturing process of the multi-chip module. The electrical test to do so should be extremely suitable and easy.

[0008]

[Means for Solving the Problems]

 In order to solve the above problems, according to the present invention, a plurality of circuit elements such as bare IC chips are die-bonded to a wiring board on which a wiring pattern is formed, and each circuit element is interconnected by a wiring pattern. In a multi-chip module that constitutes a circuit, it is possible to electrically cut the wiring pattern by forming a cutting portion having a connection pad that can be connected in a separate process in at least a part of the wiring pattern that interconnects the circuit elements. It was done like this.

Further, it is convenient to form a test pad composed of exposed electrodes connected to correspond to a wiring pattern connected to each IC chip on the surface of the wiring board.

[0010]

[Action]

 In this way, by forming a disconnection part that can be connected in a separate process in the wiring pattern, at the stage where the circuit element is mounted on the wiring board and connected by wire bonding, at least the terminals that affect the inspection of each circuit element are interconnected. It can be configured to not run and is also disconnected from the delay-affecting line. Therefore, by connecting the probe of the tester to this disconnection part or test pad in the electrical test that is performed after mounting each circuit element, it is suitable without being affected by the capacitance of other circuit elements or wiring. Certainly, the test can be performed easily and the adjustment of complicated parameters becomes unnecessary. Therefore, in the manufacturing process of the multi-chip module, the time of the electrical test process is shortened, the reliability is improved, and the quality of the multi-chip module can be improved.

[0011]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a top view of a multi-chip module according to an embodiment of the present invention in a manufacturing process. FIG. 2 is a partially enlarged view of the peripheral portion of one IC chip mounted on the multi-chip module of FIG.

In these figures, bare IC chips 1a to 1d are die-bonded to a wiring board 2 on which a wiring pattern is formed. Although the wiring pattern is not shown, it is made of a conductive material such as Cu provided in or on an insulating member such as glass epoxy or ceramic that constitutes the substrate, and is laminated alternately with the insulating member to form a multilayer wiring board. Is formed. A second pad 6 is formed on the exposed portion of the wiring pattern around the die bonding portion of the bare IC chips 1a to 1d of the wiring board 2, and the bonding pad 4 of the bare IC chip and the bonding wire 5 such as Au thin wire are used for the wire bonding connection. Has been done.

A test pad 3 is formed on the surface of the wiring board 2 around the die bonding portion. The test pad 3 is an exposed electrode formed by connecting corresponding to all wirings connected to the bonding pad 4 of the bare IC chip.

Furthermore, on the surface of the wiring board 2 on the side opposite to the bare IC chip of the test pad 3, connection pads 7a and 7b are formed close to each other. The connection pads 7a and 7b are provided on the wirings that connect the bare IC chips 1a to 1d and the wirings that are affected by the delay, that is, the critical lines, and are mainly formed on the wirings that are connected to the test pad 3. It When the IC chip is mounted and the wire bonding is connected, the connection pads 7a and 7b are not connected to each other and the wiring is cut off. It is connected by a bonding wire 8 such as Au.

Although only one set of connection pads 7a and 7b has been described here, the same applies to the other sets.

In the multi-chip module having such a configuration, the connection pads 7a and 7b are not connected when the bare IC chips 1a to 1d are die-bonded to the wiring substrate 2 and the wire bonding is completed during the manufacturing process. Since the wiring is cut, for example, at least the terminals of the IC chip 1a that influence the inspection are not connected to the other IC chips 1b to 1d, and are not connected to the lines affected by the delay. Therefore, the bare IC chip 1a is in a circuitly separated state. Therefore, when conducting an electrical test of the characteristics of each IC chip and the connection state of the bonding wire 5 after the mounting and wiring of the bare IC chip, there is no influence from the capacity of other IC chips or wiring, so it is appropriate. The test can be performed at any time and the conventional adjustment of complicated parameters becomes unnecessary.

Since the test pad 3 is provided corresponding to each wiring connected to the bonding pad of the IC chip, connecting the probe of the tester to the test pad 3 causes wire bonding to the IC chip. You can easily test all connected wires.

In this way, when the electrical test of the bare IC chips 1a to 1d is completed during the manufacturing process of the multi-chip module and no defect is found, the connection pads 7a and 7b are bonded. Connected by wire 8. As a result, the wiring connecting the IC chips is electrically connected, and the formation of the electronic circuit of the multichip module is completed. Finally, the entire circuit including the bare IC chip is hermetically sealed with resin or the like.

In this embodiment, the connection pads 7a and 7b are connected by the bonding wires 8. However, the means is not limited to wire bonding as long as it can be connected in a separate process, and it can be connected by soldering or the like. Good.

In this embodiment, the case where the bare IC chip is mounted as a circuit element on the multi-chip module has been described, but other elements such as an inductor and a ceramic filter may be used.

[0021]

[Effect of device]

 As described above, according to the present invention, in a multi-chip module in which a plurality of circuit elements such as bare IC chips are directly mounted on a wiring board on which a wiring pattern is formed and interconnected to form a circuit, at least the wiring pattern is formed. By providing a cutting portion having a connection pad that can be connected in a separate step, each IC chip can be separated in circuit. Therefore, when an electrical test is performed after the IC chip is mounted and the wiring is connected, it is not affected by the connection with other IC chips or the capacitance of the wiring pattern, so that complicated parameter adjustment is not required and the electrical The target test can be performed accurately and easily, and the test time can be greatly reduced.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of a multi-chip module according to an embodiment of the present invention.

FIG. 2 is a partially enlarged view showing in detail the configuration of part of the multi-chip module of FIG.

[Explanation of symbols]

 1a-1d IC chip 2 Wiring board 3 Test pad 4 Bonding pad 5 Bonding wire 6 Second pad 7a, 7b Connection pad 8 Bonding wire

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01L 23/538

Claims (3)

[Scope of utility model registration request] 1. A multi-chip module in which a plurality of circuit elements are die-bonded to a wiring board on which a wiring pattern is formed, and each circuit element is interconnected by the wiring pattern to form a circuit. At least one of the wiring patterns is provided. A cutting portion for electrically disconnecting the wiring pattern,
A multi-chip module, wherein the cutting parts can be electrically connected to each other in separate steps. 2. The multi-chip module according to claim 1, wherein a test pad electrically connected to a wiring connected to the circuit element is formed on the wiring board. 3. The multi-chip module according to claim 1, wherein the multi-chip module has connection pads that are connected to both ends of the cut portion and are adjacent to each other to electrically connect the cut portions to each other in a separate process.