JP2001036309A - Multichip module connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize a characteristic impedance at a connection part by providing a connection part of a dielectric substrate and a microwave(MM) IC chip with a film-shaped coplanar type connection line, in which a line is adhesion formed on a flexible film in parallel and mutually connecting signal lines of the dielectric substrate and the microwave IC chip. SOLUTION: A microstrip line 3 on a dielectric substrate 2 is a structure, in which a gap is provided between a connection part grounding pattern 101 and itself, and the line forms a coplanar line with a grounding conductor. A gap between the connection part pattern 101 and the microstrip line 3, the width of the microstrip line 3 and their shape are set so that a transmission signal communicating through the microstrip line 3 is converted and transmitted efficiently to the coplanar line with the grounding conductor. The dielectric substrate 2 and an MMIC chip 6 mounted on it are mutually connected by a film-shaped coplanar type connecting line 100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-chip module (MCM) connection structure, particularly a MM having an RF (radio frequency) prober measuring section at a coplanar line or at an input / output end.
The present invention relates to a connection structure for connecting microwave circuit elements, which are dielectric substrates constituting an IC (monolithic microwave integrated circuit) chip, a microstrip line, or a coplanar line, using connection lines.

[0002]

2. Description of the Related Art In a microwave circuit, a microwave integrated circuit composed of a high-frequency transistor, an FET (field effect transistor), a resistor and a capacitor (capacitor) is monolithically mounted on a substrate such as a semiconductor crystal (GaAs, Si, etc.). An MMIC chip integrated into a semiconductor device has significant advantages such as small size, high reliability, and low price.

In recent years, MCM technology for configuring an electronic device module using a plurality of such MMIC chips has been studied. Conventionally, this MCM technology employs an MMIC chip,
Mount the dielectric substrate etc. that constitute the microwave circuit,
A structure in which these are connected by a bonding wire or a ribbon is generally used. A technique using the MCM connection structure is disclosed in, for example, Japanese Patent Application Laid-Open No. 9-148524, entitled "High Frequency Circuit Device". That is, the connection structure is a pseudo coplanar line.

[0004] Such an MCM connection structure will be described with reference to FIGS. 8 is a perspective view of a conventional MCM connection structure, FIG. 9 is a top view, and FIG. 10 is a cross-sectional view taken along line AA ′ of FIG. This MCM connection structure is based on the base substrate 16
It has a plurality of MMIC chips 6 arranged on the “0”. Each MMIC chip 6 has a ground conductor 9 on the back surface and an input / output signal line end 8 on the top surface. An MMIC chip ground terminal 5 connected to a ground conductor 9 via a via hole 7 is provided near an end of each MMIC chip 6. The signal lines 8 and the ground terminals 5 of the MMIC chips 6 disposed opposite to each other are interconnected by a pseudo-coplanar line 11 with a ground conductor formed of a gold wire or a gold ribbon. In this prior art, a resin 12 containing a high dielectric material 13 is provided immediately below the pseudo coplanar line 11 with a ground conductor.

[0005] The pseudo coplanar connection line with the ground conductor configured as described above can suppress the characteristic impedance mismatch at the connection portion. Further, the characteristic impedance of the connection line can be controlled in a wide range by changing the material and the mixing density of the dielectric resin 12 and the high dielectric material contained therein.

A related technique is disclosed in Japanese Patent Application Laid-Open No. 63-2335.
No. 46, “Input signal transmission circuit”, JP-A-7-245
No. 11, "Hybrid integrated circuit", JP-A-6-37202
Publication "Microwave IC Package",
No. 8,855, "Microwave band IC package" and Japanese Patent Application Laid-Open No. 61-234055, "Semiconductor Device".

[0007]

However, in the above-mentioned prior art, since the three lines for signal and for installation are composed of independent gold wires or gold ribbons, the length of the connection line (L1), It is impossible to ground the width (W1) and the height (h1) between the connection lines equally and parallel to all three lines.
In addition, the three lines may change to different shapes due to vibration or acceleration, and all of these will cause variations in characteristic impedance.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an MCM connection structure that stabilizes the characteristic impedance at a connection portion in an MCM, and that can quantitatively control the characteristic impedance of a connection line over a wide range and can easily connect. .

[0009]

In order to solve the above-mentioned problems, a multi-chip module connection structure according to the present invention comprises:
The following characteristic configuration is adopted.

(1) A multi-chip module connection structure in which a microwave IC chip is directly mounted on a dielectric substrate and a signal line of the microwave IC chip and a signal line on the dielectric substrate are interconnected. A connecting portion between the dielectric substrate and the microwave IC chip, a film-shaped coplanar type connecting line in which a line is formed in parallel on a flexible film, and the dielectric substrate and the microwave IC chip are provided. A multi-chip module connection structure for interconnecting the signal lines.

(2) The multi-chip module connection structure according to (1), wherein the film-shaped coplanar type connection line and the signal line are connected using a microcapsule type anisotropic conductive adhesive.

(3) The signal line of the dielectric substrate is:
The multichip module connection structure according to the above (1) or (2), which is a microstrip line.

(4) The signal line of the dielectric substrate is:
The multi-chip module connection structure according to the above (1) or (2), which is a coplanar line having a signal line and a ground pattern.

(5) In a multi-chip module connection structure for interconnecting signal lines and ground terminals of a plurality of microwave IC chips directly mounted on a dielectric substrate,
A film-like coplanar type connection line in which lines are formed in parallel on a flexible film is provided on a facing portion of the microwave IC chip, and the film between the signal line and the ground terminal of the microwave IC chip is the film. Multi-chip module connection structure interconnected by coplanar connection lines.

(6) The multi-chip module connection structure according to (5), wherein the film-shaped coplanar connection lines are connected using a microcapsule-type conductive adhesive applied to the surface.

(7) The multi-chip module connection structure according to (5) or (6), wherein each of the microwave IC chips has a ground conductor on a back surface, and the ground conductor and the ground terminal are connected by a via hole.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction and operation of a preferred embodiment of a multi-chip module (MCM) connection structure according to the present invention will be described below in detail with reference to the accompanying drawings, particularly FIGS. Note that, for convenience, the same reference numerals are used for components corresponding to the above-described components of the related art.

First, FIGS. 1 to 3 show an MC according to the present invention.
FIG. 1 is a perspective view, FIG. 2 is a top view, and FIG. 3 is a sectional view taken along line AA ′ in FIG.

The MCM connection structure shown in FIGS.
This is an example in which the MMIC chip 6 is connected to the dielectric substrate 2.
The dielectric substrate 2 has a ground conductor 1 on the back surface and a microstrip line (signal line) 3 and a connection part ground pattern 101 on the upper surface. On the other hand, the MMIC chip 6
Has a ground conductor 9 on the back surface and an input / output signal line 8 on the top surface.
And a ground terminal 5. Further, the MMIC chip 6
There is a via hole 7 communicating between the ground conductor 1 on the back surface and the ground terminal 5.

The microstrip line 3 on the dielectric substrate 2 has a structure in which a gap g is provided between the microstrip line 3 and the connection portion ground pattern 101, and the line forms a coplanar line with a ground conductor. The gap g between the connection ground pattern 101 and the microstrip line 3 and the width and shape of the microstrip line 3 are set so that the transmission signal transmitted through the microstrip line 3 is efficiently converted and transmitted to the coplanar line with the ground conductor. Set.

Dielectric substrate 2 and MMI mounted thereon
Between the C chips 6, a film-shaped coplanar connection line 10
0 interconnected. The film-shaped coplanar connection line 100 has conductive foils which are arranged in parallel with a constant width and a constant interval on the surface of a dielectric film having extremely high flexibility and heat resistance.

FIG. 4 shows a film-shaped coplanar type connection line 100 obtained by improving a film carrier with a ground conductor having a coplanar line disclosed in, for example, JP-A-2-91956. This film-shaped coplanar connection line 100 has a first connection line 120 and a second connection line 121 on both sides of the first connection line 120 attached to the upper surface of a flexible insulating film (dielectric layer) 123 via an adhesive layer 122. Form. Further, a microcapsule type anisotropic conductive adhesive 134 is applied to these surfaces to form a coplanar type connection line. According to the film-like coplanar connection line 100 having such a configuration, the characteristic impedance Z0 is equal to the first impedance.
And the widths W3 and W4 of the second connection lines 120 and 121, the pitch (interval) P between the lines 120 and 121, the dielectric thickness h3, the relative permittivity of the dielectric, and the line conductor thickness t. It is well known. By appropriately selecting these parameters, the characteristic impedance Z0 of the connection line is set to a desired value.

A film-like coplanar type connection line 100 as shown in FIG. 4 is connected to the microstrip line 3 on the dielectric substrate 2 and the input / output end of the MMIC chip 6, and the first connection line 120 is a microstrip line. 3
And the signal line 8 of the MMIC chip 6, and the second connection line 121 is connected to the ground terminal 5 of the MMIC chip 6 and the connection ground pattern 101 on the dielectric substrate 2. The connection method or means is shown in an enlarged sectional view in FIG. That is, the film-shaped coplanar type connection line 100 having the surface coated with the microcapsule type anisotropic conductive adhesive 134 is turned upside down.
(Face down), and a pressure is applied to the connection between the connection lines 120 and 121 from above. Thus, the microcapsule type anisotropic conductive adhesive 134 is electrically and mechanically connected. The microcapsule type anisotropic conductive adhesive 134 is made of conductive metal particles 1 coated with an insulating layer (resin) 130 having excellent electrical insulation and moisture resistance.
31 is an adhesive, and by pressurizing the connection portion, the connection between the connection line 133 and the connection lines 120 and 121 is electrically conducted via the conductive metal particles 132 in which the coating on the outer periphery of the metal particles 131 is broken. Connecting.

With such a connection structure, the length L2 of each connection line, which causes a problem of characteristic impedance variation in the conventional structure,
Variations in the width W2 and the height h2 can be made uniform. Also,
Note that the characteristic impedance Z0 is extremely stable even when the shape of the connection line changes due to heat, vibration and shock. Also, as described above, the connection line 1
The characteristic impedance of the microstrip line 3 on the dielectric substrate 2 can be adjusted by selecting a parameter.
And can be controlled in a wide range according to the characteristic impedance of the signal line 8 of the MMIC chip 6.

As shown in FIG. 4, according to the MCM connection structure shown in FIGS. 1 to 3 in which film-shaped coplanar connection lines 100 are connected by a connection method as shown in FIG. R input from the input end
The F signal is transmitted through the microstrip line 3. M
Before the connection with the MIC chip 6, the signal is converted into a signal transmitted through a coplanar line with a ground conductor composed of the microstrip line 3 and the connection ground pattern 101. Furthermore,
MM is transmitted through the film-shaped coplanar connection line 100.
It is supplied to the input terminal of the IC chip 6. Although not shown in FIGS. 1 to 3, the operation between the output terminal of the MMIC chip 6 and the microstrip line of the dielectric substrate 2 is the same as that of the input terminal. Coplanar film connecting line 10
By matching the characteristic impedance of 0 with the characteristic impedance of the microstrip line 3 and the signal line 8 of the MMIC chip 6, interconnection is possible without signal distortion or loss.

[0026]

Next, another embodiment of the multi-chip module connection structure according to the present invention will be described with reference to FIGS. 6 and 7. FIG.

FIG. 6 is a perspective view of a multi-chip module connection structure according to a second embodiment of the present invention. This M
The CM connection structure is similar to the MCM connection structure of the first embodiment shown in FIGS. The main difference is that a signal line 151 and a coplanar line including a ground pattern 150 surrounding the signal line 151 are formed on the upper surface of the dielectric substrate 2 '. The coplanar lines 151 and 150 are interconnected to the signal line 8 and the ground terminal 5 of the MMIC chip 6 by a film-shaped coplanar connecting line 100.
The MMIC chip 6 has a signal line 8 and a ground terminal 5 on the upper surface and a ground conductor 9 on the back surface, similarly to the MMIC chip 6 of FIG. Further, the ground terminal 5 and the ground conductor 9 are connected by the via hole 7. The connection between the film-shaped coplanar connection line 100 and the dielectric substrate 2 and the MMIC chip 6 may be performed by the method described with reference to FIG.

FIG. 7 is a perspective view of a third embodiment of the MCM connection structure according to the present invention. According to this MCM connection structure, a pair of MMs mounted on the dielectric substrate 160
The IC chip 6 is connected to the film-shaped coplanar connection line 1
The case of interconnection using 00 is shown. That is, the signal line 8 and the ground terminal 5 of the pair of MMIC chips 6 and 6 mounted on a dielectric substrate (base substrate) 160 which is made of a metal or a whole conductor are connected to the film-like coplanar connection line 10.
Connect at 0. This film-shaped coplanar type connection line 100 may be the same as the film-shaped coplanar type connection line 100 shown in FIG. 4, and the lines 120 and 121 establish a characteristic impedance matching state between the signal line 8 and the ground terminal 5 of each MMIC chip 6. To interconnect. As described above, it is preferable to use a microcapsule type anisotropic conductive adhesive.

The configuration and operation of the preferred embodiment of the MCM connection structure according to the present invention have been described above in detail. However, the present invention should not be limited to only the specific examples described above, and various modifications can be made without departing from the gist of the present invention. For example, in the MMIC chip, a coplanar line with a ground conductor may be formed not only at the input / output signal line end but also over the entire surface of the MMIC chip. The connection may be made by a method other than the conductive adhesive.

[0030]

As will be understood from the above description, according to the MCM connection structure of the present invention, the microstrip line or coplanar line on the dielectric substrate and the signal line of the MMIC chip are formed using a film-shaped coplanar connection line. , And can be stably connected in a characteristic impedance matching state. Further, the use of the microcapsule type anisotropic conductive adhesive has a remarkable practical effect that the module can be miniaturized because it can be connected simply and automatically.

[Brief description of the drawings]

FIG. 1 is a perspective view of a first embodiment of an MCM connection structure according to the present invention.

FIG. 2 is a top view of the MCM connection structure of FIG. 1;

FIG. 3 is a cross-sectional view of the MCM connection structure of FIG. 2 taken along line AA ′.

FIG. 4 is a perspective view of a preferred example of a film-shaped coplanar connection line used for the MCM connection structure according to the present invention.

FIG. 5 is an enlarged sectional view showing a connection state of the film-shaped coplanar connection line of FIG. 4;

FIG. 6 is a perspective view of a second embodiment of the MCM connection structure according to the present invention.

FIG. 7 is a perspective view of a third embodiment of the MCM connection structure according to the present invention.

FIG. 8 is a perspective view of a conventional MCM connection structure.

FIG. 9 is a top view of the MCM connection structure of FIG. 8;

FIG. 10 is a cross-sectional view of the MCM connection structure of FIG. 9 taken along line AA ′.

[Description of Signs] 1, 9 Ground conductor 2, 2 ', 160 Dielectric substrate (base substrate) 3, 8 Signal line 5 Ground terminal 6 Microwave IC chip (MMIC chip) 7 Via hole 100 Film-shaped coplanar connection line 101 Connection part ground pattern 120, 121 Connection line 123 Dielectric layer 130 Insulation layer 131 Metal particles 134 Microcapsule type anisotropic conductive adhesive 150, 151 Coplanar line

Claims (7)

[Claims] 1. A multi-chip module connection structure for directly mounting a microwave IC chip on a dielectric substrate and interconnecting a signal line of the microwave IC chip and a signal line on the dielectric substrate. A connecting portion between the dielectric substrate and the microwave IC chip is provided with a film-shaped coplanar type connecting line in which a line is formed in parallel on a flexible film, and a connection between the dielectric substrate and the microwave IC chip is provided. A multi-chip module connection structure, wherein the signal lines are interconnected. 2. The film-shaped coplanar connection line,
2. The multi-chip module connection structure according to claim 1, wherein the signal lines are connected using a microcapsule type anisotropic conductive adhesive. 3. The multi-chip module connection structure according to claim 1, wherein the signal line of the dielectric substrate is a microstrip line. 4. The multichip module connection structure according to claim 1, wherein said signal line of said dielectric substrate is a coplanar line having a signal line and a ground pattern. 5. A multi-chip module connection structure for interconnecting signal lines and ground terminals of a plurality of microwave IC chips directly mounted on a dielectric substrate, wherein a flexible portion is provided on a facing portion of the microwave IC chip. A film-like coplanar connection line in which lines are formed in parallel on a conductive film, and the signal line and the ground terminal of the microwave IC chip are interconnected by the film-like coplanar connection line. Multi-chip module connection structure. 6. The multi-chip module connection structure according to claim 5, wherein said film-shaped coplanar connection lines are connected using a microcapsule-type conductive adhesive applied to the surface. 7. The multi-chip module according to claim 5, wherein each of the microwave IC chips has a ground conductor on a back surface, and the ground conductor and the ground terminal are connected by a via hole. Connection structure.