JPH0454701A - Input/output terminal for semiconductor module - Google Patents

Abstract

PURPOSE:To reduce the loss of an input/output line part in an ultrahigh frequency band by providing a thick part to a rear side of a ceramic substrate corresponding to a ceramic wall. CONSTITUTION:An end of a strip conductor 45 of an input/output terminal 40 at the inside of a package is connected to an input/output strip conductor of a hybrid integrated circuit 15 via a connection line and the input/output line of the hybrid integrated circuit 15 is led at the outside of a metallic package 11. The conductor width of the conductor 45 is selected equal to the conductor width of a strip conductor 25 of a microstrip line 20. Moreover, a sintered thick part 50-1 is provided to a lower face of a ceramic substrate 42 opposite to a ceramic wall 43. Moreover, a ground conductor layer 44 is formed to the entire bottom face of the ceramic substrate 42 including the bottom of the thick part 50-1. Thus, the characteristic impedance of the terminal 40 is a prescribed impedance, 50ohms, its resistive component is small and a loss at the terminal 40 is suppressed low.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a semiconductor module in which a high-frequency integrated circuit is housed and sealed in a metal package, and particularly regarding the input/output terminals of the semiconductor module, the loss of the input/output line portion is small even in the ultra-high frequency band.
The purpose is to provide input/output terminals for semiconductor modules, and the input/output terminals have a strip line structure and are sealed to the side wall of the package of the semiconductor module. , a ceramic wall portion protruding from the top surface of the ceramic substrate portion with a rectangular cross section and integrally fired; The ceramic substrate has a structure including a thick part that is integrally fired and a ground conductor layer formed on the entire bottom surface of the ceramic substrate part including the bottom surface of the thick part.

[Industrial application field]

The present invention relates to a semiconductor module in which a high-frequency integrated circuit is housed and sealed in a metal package, and particularly relates to input/output terminals of a semiconductor module.

FIG. 4 is a diagram of a semiconductor device in which high-frequency hybrid integrated circuits are combined as desired, in which (a) is a partially cutaway plan view;
(b) is a partially cutaway side view, and (C) is a perspective view of the semiconductor module.

In FIG. 4, 10 is a shallow metal package (made of copper, copper-tungsten, iron-nickel-cobalt alloy, etc.) with an opening at the top. 11 houses a hybrid integrated circuit 15, and the opening is covered with a cover 14. It is a semiconductor module that is soldered and sealed.

The hybrid integrated circuit 15 is a high-frequency (microwave/millimeter wave band) circuit board in which a film circuit is formed on the surface of a thin circuit board C made of alumina ceramics (for example, 0.33++ on), and a semiconductor chip, etc. is mounted on the surface. It is a hybrid integrated circuit.

The hybrid integrated circuit 15 is housed in the metal package 11 by providing a ground conductor layer on the back surface of the circuit board by metallizing gold or the like, and by brazing this ground conductor layer in close contact with the package bottom plate 12.

On the other hand, the input/output terminals 30 having a strip line structure are sealed to the opposing side walls 13 of the package, and the ends of the strip conductors 35 of the input/output terminals 30 inside the package are bonded by thermocompression with connection wires such as gold ribbon. By connecting to the input/output strip conductor of the hybrid integrated circuit 15, the input/output line of the hybrid integrated circuit 15 is drawn out of the metal package 11.

20 is a dielectric substrate such as alumina ceramics (thickness is 0.33 mm, for example).
．． This is a microstrip line in which a strip conductor 25 (336 mm) is provided, and a ground conductor layer 24 is formed by vapor-depositing gold or the like on the entire back surface.

I is a box-shaped metal case with an open top made of aluminum, copper-based metal, etc., and the opposing case side wall I
A coaxial connector 4 is attached to B.

By closely fitting the package bottom plate 12 to the top surface of the case bottom plate 1^ and fixing it using machine screws (not shown), a plurality of semiconductor modules IO are arranged in the metal case l, and the microstrip line 20 is connected to the strip conductor 25. The back surface thereof is soldered and fixed to the case bottom plate IA so as to face the strip conductor 35 of the input/output terminal 30.

Then, the strip conductor 35 of the input/output terminal 30 and the strip conductor 25 of the microstrip line 20 are connected via the connecting wire 7 by thermocompressing both ends of the connecting wire (for example, gold ribbon) 7. .

Furthermore, the other end of the strip conductor 25 of the microstrip line 20 is connected to the center conductor of the coaxial connector 4.

Note that the opening of the metal case l is closed by screwing the cover 2.

At this time, as the performance of semiconductor modules increases, wireless devices with a higher frequency (40 GHz to 50 GHz) than the conventionally used frequency band (microwave band) are being developed.

Due to this, input/output terminals with excellent characteristics in the ultra-high frequency band are required.

[Conventional technology]

By the way, the conventional input/output terminal 30 has a structure as shown in FIG.

5) is a perspective view of the input/output terminal, and fb) is a plan view.

In Fig. 5, the input/output terminal 3 of the stripline structure
0 is a ceramic substrate portion 32 such as alumina ceramics.
A strip conductor 35 is formed at the center of the upper surface (with a plate thickness of, for example, 0.33 mm), and a ceramic wall 33 having a rectangular cross section is provided on the upper surface of the ceramic substrate 32 so as to cross over the strip conductor 35. It is something.

Then, a ground conductor layer 34 is provided by depositing gold or the like on the entire lower surface of the ceramic substrate section 32.

Incidentally, the impedance of the input/output line of the input/output terminal 30 needs to be 50Ω, which is equal to the characteristic impedance of the transmission line system.

On the other hand, as shown in detail in FIG. It consists of an internal pattern portion 35B sandwiched with.

Therefore, in order to have the same characteristic impedance as the input/output line or the microstrip line of the hybrid integrated circuit, the radiation B2 of the internal pattern part 35B is set to the exposed part pattern part 3.
The width is desirably smaller than the width B1 of 5A.

For example, the width B1 of the exposed part pattern 35A is 0.336 m, which is equal to the strip conductor width of the microstrip line.
m, whereas the width B2 of the internal pattern 35 is '
It is 0.1 mm.

The above-mentioned input/output terminal 30 is made by printing a conductive paste (paste containing tungsten metal) in a band shape on a ceramic substrate part 32 in the form of a green sheet, and then printing a ceramic wall part in the form of a green sheet on top of the conductive paste (paste containing tungsten metal). 33 and were integrated by overlapping and firing.

Note that the width of this ceramic wall portion 33 is approximately equal to the thickness of the side wall of the package.

As shown in FIG. 4(C), the input/output terminal 30 is fitted into a notch in the side wall of the package, and the ground conductor layer 34 is soldered to the bottom plate of the package.

Then, the input/output terminal 30 is sealed to the metal package by bonding the top and side surfaces of the ceramic wall portion 33 to the side wall of the package by soldering or using an adhesive.

[Problem to be solved by the invention]

By the way, since the input/output terminals are formed by sintering, a tungsten-based metal with high resistivity is used for the strip conductor as described above.

The strip conductor has an exposed pattern portion with a large conductor width and an internal pattern portion with a small conductor width.

Therefore, the problem with conventional input/output terminals is that even though the characteristic impedances are equal, the loss in the input/output line section cannot be reduced below the desired value due to the large resistance of the internal pattern section. was there.

The present invention was created in view of these points, and an object of the present invention is to provide an input/output terminal for a semiconductor module that has low loss in the input/output line portion even in an ultra-high frequency band.

[Means to solve the problem]

In order to achieve the above object, the present invention, as illustrated in FIG. 1, forms input/output terminals 40 of a strip line structure on the upper surface of a ceramic substrate section 42 to be sealed to the side wall portion of a package of a semiconductor module IO. A strip conductor 45 in the form of a band having a constant width; a ceramic wall 43 protruding from the top surface of the ceramic substrate 42 with a rectangular cross section so as to cross over the strip conductor 45 and integrally fired; A thick portion 50-1 and a thick portion 50-1 are integrally fired on the lower surface side of the ceramic substrate portion 42.
A ground conductor layer 44 is formed on the entire bottom surface of the ceramic substrate section 42, including the bottom surface of the ceramic substrate section 42.

Further, as illustrated in FIG. 2, the side view cross-sectional shape of the thick wall portion 50-2 in which the input/output terminal 40-2 is provided on the lower surface of the ceramic substrate portion 42 is such that the central portion corresponding to the ceramic wall portion 43 is At best, it should be in an inverted mountain shape with lower left and right sides like steps.

Furthermore, as illustrated in FIG. 3, the input/output terminal 40
-3 is the thick part 5 provided on the lower surface of the ceramic substrate part 42.
The cross-sectional shape of 0-3 in side view is made into an inverted mountain shape with the highest point at the center corresponding to the ceramic wall portion 43 and gently lowering on the left and right sides.

[Effect]

As described above, the conductor width of the inner no-turn portion of the strip conductor 45 is expanded to be equal to the conductor width of the exposed no-turn portion, and the ceramic substrate portion 42 is expanded to correspond to the ceramic wall portion 43. A thick portion 50-1 is provided on the lower surface of the holder.

Therefore, the input/output terminal 40 of the present invention has a characteristic impedance of a predetermined value of 50Ω and a small resistance value.

In other words, the loss at the input/output terminals can be kept low.

Also, the second. In the third invention, since the side view cross section of the thick portion is an inverted mountain shape, the electric field mode does not undergo a sudden mode conversion when converting from the exposed portion (the turned portion to the internal pattern portion).

Therefore, impedance deterioration due to sudden changes in electric field mode is prevented.

〔Example〕

The present invention will be specifically described below with reference to the drawings. Note that the same reference numerals indicate the same objects throughout the figures.

FIG. 1 is a diagram of an embodiment of the first invention, in which (a) is a side sectional view of a semiconductor device, fb) is a perspective view of an input/output terminal, and FIG. 2 is a side sectional view of the second invention. FIG. 3 is a side sectional view of the third invention.

In FIG. 1, IO is a semiconductor module in which a hybrid integrated circuit 15 is housed in a shallow metal package 11 with an open top, and a cover 14 is placed over the opening and sealed by brazing.

The hybrid integrated circuit 15 is an ultra-high frequency band hybrid integrated circuit in which a film circuit is formed on the surface of a thin circuit board (thickness: 0.33 mm) made of alumina ceramics, etc., and a semiconductor chip and the like are mounted on the surface. A ground conductor layer is provided by metallizing gold or the like on the back side of the circuit board, and this ground conductor layer is closely attached to the package bottom plate and brazed to the metal package 11.
It is stuck to.

On the other hand, the input/output terminals 40 having a strip line structure are sealed to the opposing side walls 13 of the package, and the ends of the strip conductors 45 of the input/output terminals 40 inside the package are connected via connecting wires such as gold ribbons to By connecting to the input/output strip conductor of the integrated circuit 15, the input/output line of the hybrid integrated circuit 15 is drawn out of the metal package 11.

As shown in FIG. 1(b), the input/output terminal 40 is formed by forming a band-shaped strip conductor 45 in the center of the upper surface of a ceramic substrate 42 (thickness: 0.33+mm) made of alumina ceramics or the like. be.

The conductor width of this strip conductor 45 is
The exposed pattern portions are equal and equal to the conductor width of the strip conductor 25 of the microstrip line 20 0.33
6 un. Moreover, the material is tungsten metal.

On the other hand, a ceramic wall portion 43 having a rectangular cross section and projecting from the upper surface of the ceramic substrate portion 42 so as to cross over the strip conductor 45 is baked and integrated.

Further, a prismatic thick part 50-1 is provided by firing on the lower surface side of the ceramic substrate part 42, facing the ceramic wall part 43.

Note that the ceramic substrate portion 4 including the bottom surface of the thick portion 50-1
A ground conductor layer 44 is formed on the entire bottom surface of 2 by vapor-depositing gold or the like.

Since the configuration is as described above, the characteristic impedance of the input/output terminal 40 having the strip line structure is equal to the characteristic impedance of a transmission line system such as a microstrip line 20, which will be described later, and is 50Ω.

The input/output terminal 40 fits into a notch in the side wall of the package,
Solder the ground conductor layer 44 to the recess of the package bottom plate,
By bonding the top and side surfaces of the ceramic wall portion 43 to the package side wall 13 using soldering or adhesive,
It is sealed to a metal package 11.

On the other hand, a dielectric substrate such as alumina ceramics (thickness is 0
．． 33mm) 21 surface, narrow width (width is 0.336M)
A strip conductor 25 of In) is provided, gold or the like is deposited on the entire back surface to form a ground conductor layer, and the semiconductor module 1 is assembled.
A microstrip line 20 connects the coaxial connector 4 and the coaxial connector 4.

Note that the characteristic impedance of this microstrip line 20 is 50Ω.

Then, as shown in FIG. 1(a), the package bottom plate is brought into close contact with the top surface of the case bottom plate of a box-shaped metal case l with an open top, and fixed using machine screws (not shown). The semiconductor modules 1O are arranged in a metal case 1, and the microstrip tube line 20 is fixed by soldering the back side to the bottom plate of the case so that the strip conductor 25 faces the strip conductor 45 of the input/output terminal 40. ing.

Then, the strip conductor 45 of the input/output terminal 40 and the strip conductor 25 of the microstrip line 20 are connected via the connecting wire 7 by thermocompressing both ends of the connecting wire (for example, gold ribbon) 7. .

In addition, the strip conductor 2 of the microstrip line 20
The other end of 5 is connected to the center conductor of coaxial connector 4.

The above-described input/output terminal 40 has a small resistance value because the conductor width of the internal pattern portion of the strip conductor 45 is equal to and wide as the conductor width of the exposed pattern portion.

Therefore, the loss in the input/output line portion is small when applied to the ultra-high frequency band of 40 GHz to 50 GHz.

The input/output terminal 40-2 shown in FIG. A ceramic wall portion 43 having a rectangular cross section protruding from the upper surface of the substrate portion 42 is fired and integrated,
Furthermore, the lower surface side of the ceramic substrate part 42 facing the ceramic wall part 43 is made thicker to form a thicker part 50-2.

The cross-sectional shape of the thick portion 50-2 in side view is made into an inverted chevron shape, with the center portion corresponding to the ceramic wall portion 43 being highest, and the left and right sides being lower in a stepped manner.

Note that the ceramic substrate portion 4 including the bottom surface of the thick portion 50-2
A ground conductor layer 44 is formed on the entire bottom surface of 2 by vapor-depositing gold or the like.

On the other hand, the input/output terminal 40-3 shown in FIG. -3.

The cross-sectional shape of the thick portion 50-3 in side view is made into an inverted chevron shape, which is highest at the center corresponding to the ceramic wall portion 43 and gradually lowers from side to side.

Further, the ceramic substrate portion 4 including the bottom surface of the thick portion 50-3
A ground conductor layer 44 is formed on the entire bottom surface of 2 by vapor-depositing gold or the like.

Input/output terminals 40-2 and 40-3 shown in FIGS. 2 and 3 have an inverted chevron cross section in side view of the thick portion, so the electric field mode is converted from the exposed pattern portion to the internal pattern portion. Since there is no sudden mode conversion, impedance deterioration due to sudden changes in the electric field mode is prevented.

[Effects of the Invention] As explained above, the present invention provides a thick wall portion on the back side of the ceramic substrate portion corresponding to the ceramic wall portion.
This is an input/output terminal that has a wide conductor width to reduce the DC resistance of the strip conductor and has a specified characteristic impedance, and has the advantage of low loss in the input/output line even in ultra-high frequency bands. It has a great effect.

Also second. In addition to this effect, the third invention has the effect that deterioration of impedance due to sudden changes in electric field mode is prevented.

[Brief explanation of the drawing]

1 is a diagram of an embodiment of the first invention, (a) is a side sectional view of a semiconductor device, (b) is a perspective view of an input/output terminal, FIG. 2 is a side sectional view of the second invention, Fig. 3 is a side sectional view of the third invention, Fig. 4 is a diagram of the semiconductor device, (a) is a partially cutaway top view, (b) is a partially cutaway side view, and (e) is a semiconductor module. FIG. 5 is a diagram of a conventional example, in which (a) is a perspective view and (b) is a plan view. In the figure, 1 is a metal case, 0 is a semiconductor module, l is a metal package, 2 is a package bottom plate, 3 is a package side wall, 5 is a hybrid integrated circuit, 30, 40.40 to 2.40-3 are input/output terminals, 32,
42. 33 and 43 are ceramic wall portions; 34 and 44 are ground conductor layers; 35 and 45 are strip conductors; and 50-1.50-2.50-3 are thick portions, respectively. (α little (shi 2 (C> Semiconductor processing 1 old (α nth! ρ invention success/) record 1 Himo V review/) (ff'14 Rutomi 2nd 13th) Invention IC 01 game Conclusion 13th century Σ

Claims (1)

[Scope of Claims] [1] An input/output terminal with a strip line structure that is sealed to the side wall portion of a package of a semiconductor module, and includes a band-shaped strip conductor (45) formed on the upper surface of a ceramic substrate portion (42). and a ceramic wall (43) protruding from the top surface of the ceramic substrate (42) with a rectangular cross section so as to cross over the strip conductor (45) and integrally fired; Opposingly, the ceramic substrate part (42)
A ground conductor formed on the entire bottom surface of the ceramic substrate section (42) including the bottom surface of the thick section (50-1) and the bottom surface of the thick section (50-1). Layer (44)
An input/output terminal for a semiconductor module, comprising: [2] The side cross-sectional shape of the thick wall portion (50-2) provided on the lower surface of the ceramic substrate portion (42) is characterized by an inverted chevron shape with the center portion being highest and the left and right sides being lower in a stepped manner. The input/output terminal of the semiconductor module according to claim 1. [3] A claim characterized in that the cross-sectional shape of the thick wall portion (50-3) provided on the lower surface of the ceramic substrate portion (42) in side view is an inverted mountain shape with the center portion being highest and the left and right sides being gently lower. An input/output terminal of the semiconductor module according to item 1.