Microwave hybrid integrated circuit

(54) (56) (57)

PATENT HOLDER Samsung Electronics Co Ltd, Suwon-city KR

INVENTOR Viktor Anatolievich Iovdalsky, Fryzino RU, Eduard Volfovich Aizenberg, Fryzino RU, Vladimir Iliich Beil, Fryzino RU, Mikhail Ivanovich Lopin, Fryzino RU

OMBUD Zacco Sweden AB (publ)

NAME Integrated microwave hybrid circuit

CALLED PUBLICATIONS: - - SUMMARY:

Integrated microwave hybrid circuit comprising a dielectric board (1) provided with a topological metal pattern (2) on its front, with a screen grounding metalization (3) on its rear, a hole (4) and a metal base (5) having a projection (6). The hole (4) in the card (1) has a constriction (9) located at a height of 1-300 µm from the front of the card (1). The projection (6) is located in a wide section (10) of the hole (4).

Bonding intermediates (8) of a chip (7) to be ground are electrically connected to the projection (6) via the constricted portion (9) of the hole (4), which is filled with an electrically conductive and heat conducting material (11). The wide section (10) of the hole (4) is from 0.2 x 0.2 mm to the size of the chip (7) and the distance between the side walls of the projection (6) and the side walls of the wide section (10) of the hole (4) is 0.001. -1.0 mm.

<img file="SE522106C2_D0001.tif" />

The numbers in brackets indicate international identification code, INID code. Letters in clamps indicate international document code.

522 106

Summary

Integrated microwave hybrid circuit comprising a dielectric board (1) provided with a topological metal pattern (2) on its front, with a screen grounding metalization (3) on its rear, a hole (4) and a metal base (5) having a projection (6). The hole (4) in the card (1) has a constriction (9) located at a height of 1-300 gm from the front of the card (1). The projection (6) is located in a wide section (10) of the hole (4). Bonding intermediates (8) of a chip (7) to be ground are electrically connected to the projection (6) via the constricted portion (9) of the hole (4), which is filled with an electrically conductive and heat conducting material (11). The wide section (10) of the hole (4) is from 0.2 x 0.2 mm to the size of the chip (7) and the distance between the side walls of the projection (6) and the side walls of the wide section (10) of the hole (4) is 0.001. -1.0 mm.

WSPBWOL3 \ users \ FM \ DOC \ Word doc \ P33585-B.doc

522 106

FIELD OF THE INVENTION

The present invention relates generally to electronic technology and more particularly to an integrated microwave hybrid circuit (IC).

BACKGROUND OF THE INVENTION

An integrated microwave hybrid IC is known, which integrated circuit comprises a multilayer printed circuit board with a flat flexible insulating layer, on which the number of conductive contacts is provided for connection to the conductors of the modular circuit components or to the hollow. Interconnections between the contacts are provided by conductive bridge elements arranged in a single or multiple planes in the printed multilayer circuit board at the installation sites of modules or holders for the circuit components. A number of holes are made of the flexible dielectric material. A separate rigid metal element serves to extract the heat from the circuit components. Said elements are superimposed on the board in such a way that the heat conducting metal projections are inserted into the holes to contact the modules or holders of the circuit components. In addition, one or more rigid elements, which are also made of a thermally conductive material, can be applied to the upper part of the circuit components. Clips are used to provide the contact between the metal projections and the circuit components.

Flexibility of the multilayer structure prevents the concentration of mechanical stresses obtained by difference between the coefficient of thermal expansion of the multilayer structure and the circuit components. The multilayer structure can be bent between the modules or holders, which improves the contact between the projections and the circuit components and minimizes the risk of the latter being worn away from the card surface (GB, A 2 129 223).

However, the aforementioned integrated hybrid circuit IC has insufficient electrical properties and insufficient weight size properties.

In the art, a downward facing semiconductor device is known, with cylindrical projecting metal conductors being formed on the chip. The chip surface, except for the conductors, is coated with a layer of insulating resin, which has a thickness equal to the conductor height. Bonding between the chip and carrier element is accomplished using a solder that fills the conductor cavity (JP, A 57-57303).

The above-mentioned semiconductor device has poor electrical parameters when used in the microwave range, which is due to the presence of large surface contact interfaces, such as 100 x 100 gm, or large chips, for example more than 1 x 1 mm, while the most widely distributed chips within microwave technology is those having dimensions of 0.5 x 0.5 mm (or \\ SPB \ VOL3 \ users \ FM \ DOK \ word-doc \ P33585-B.doc

522 106 .2 from lxl to 0.08 x 0.08 mm) with contact intermediates, for example, from 0.03 x 0.03 to 0.015 x 0.015 mm which refers to a trend towards a minimized undesired inductance.

In addition, providing a protrusion on the metal base of a size approximately that of the contact spacer, and accurately mounting the protrusion in the card hole also poses some difficulties, especially in the case of small chips.

SUMMARY OF THE INVENTION

The main object of the present invention is to provide an integrated microwave hybrid circuit which has such a circuit arrangement that improved electrical and heat dissipation characteristics are ensured, which results in an extended operating frequency range for the circuit and reduced working effort is required in its manufacturing process.

The above object is realized due to the fact that in an integrated microwave hybrid IC, which includes a dielectric board, which is provided with a topological metal pattern on its front, a screen grounding metal on its back and a hole, the metal base being joined to the screen grounding metal protuberances, which are located in the hole of the card, wherein a bare semiconductor chip is located with its bonding intermediates towards the front of the card, wherein part of the bonding spacer is electrically connected to the topographic metallization pattern, while another part of the bonding spacer to be grounded is electrically connected to the protrusion of the metal base, according to the invention the hole in the card has a constriction located at a height from 1-300 µm from the front of the card, the projections of the metal base being placed in the wide section of the hole, wherein the chip bonding spacers are electrically connected to the metal base projection via the constricted hole section which is filled with an electrically conductive and heat conducting material, the wide hole section being from 0.2 x 0.2 mm to the chip size and the distance between the side wall walls and the side walls of the wide hole section are 0.001-1.0 mm.

The hole in the card may be metallized.

It is convenient that the space bounded between the side walls of the projection and the side walls of the hole is filled with an electrically conductive and heat conducting material.

Arrangement of holes in the constriction towards the front of the card makes it possible to provide the output of the grounding contact on the card surface so that it is comparable to the dimensions of the bonding intermediates to be ground, ie having small undesired parameters and small area, whereby the dielectric and weight properties -size can be improved.

WSPBWOL3 \ users \ FM \ DOC \ Word doc \ P33585-B.doc

522 106 * ·

The arrangement of the wide section of the hole and the location of the electrically conductive metal base in the projection ensure a better grounding quality and bring the heat conducting base to the most heated chip area, namely its front in the zone of, for example, the control of a field effect transistor or the pnip transistor of a b , thus improving the heat dissipation properties of the circuit.

Connecting the chip bonding spacers to the protrusion of the base through the restriction of the hole, which is filled with an electrically conductive and heat conducting material, ensures a good electrical contact and heat contact and thus improves the dielectric and heat dissipation properties of the circuit.

The minimum height of the hole constriction is limited to the minimum possible card thickness, while the maximum height of the hole is selected from the conditions of a minimum undesired inductance of the connection. Limiting the distance between the sidewalls of the projection and the sidewalls of the hole makes it possible to reduce the requirements of the fabrication and the alignment accuracy of holes relative to the protuberances, thereby increasing the fabricability of the circuit.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is illustrated by a detailed description of a specific exemplary embodiment thereof with reference to the accompanying drawing, in which a sectional view of the new integrated microwave hybrid circuit is reproduced.

BEST PROCEDURE FOR REALIZING THE INVENTION

The integrated microwave hybrid circuit IC according to the invention comprises a 0.5 mm thick dielectric board 1, made of, for example, Polycor and provided with a topological metal pattern on its front and with a screen grounding metalization 3 on its rear. The composition of the metal coating may be, for example, as follows: Ti (100 ohms / mm²) - Pd (0.2 pm) - Au (3 pm). The card 1 has a hole 4.

A metal base 5 is joined to the screen grounding metallization 3 by, for example, a eutectic Au-Si solder. The base 5 has a projection 6 of, for example, the size of 0.5 x 0.5 x 0.4 mm, which is located in the hole 4 of the card 1, the wide section of the hole 4 being, for example, 0.8 x 0.8 x 0.4 mm and its displacement section is 0.15 x 0.4 x 0.1 mm.

A bare semiconductor chip 7, for example the transistor 3.603 E-5 of size 0.5 x 0.45 x 0.3 mm, is mounted so that its bonding intermediate 8, each at 60 x 60 µm, faces the front of the card 1, whereby a portion of the the spacers 8 are electrically connected to the topological metal pattern 2 and some of the spacers to be ground are electrically connected to the

WSPBWOL3 \ users \ FM \ DOC \ Word doc \ P33585-B.doc

522 106 • ·. 4, the projection 6. The hole 4 in the card 1 has a narrowing 9 which is located at the front of the card 1. The protrusion 6 of the metal base 5 is located in a wide section 10 of the hole 4. The bonding inserts 8 of the chip 7 to be ground are electrically connected to the metal protrusion 6 of the base 5 via the constriction 9 of the hole 4, the constriction being filled with electrically conductive and heat conducting. material 11, for example an Au-Si solder. The narrowing 9 of the hole 4 has a length of 0.1 mm and the gap between the side walls of the projection 6 and the side walls of the wide section 10 of the hole 4 is equal to 0.15 mm.

The hole 4 in the card 1 is metallized (reference numeral 12), the composition of the metallization being, for example, Pd-Ni (0.2 µm) - Cu (3 µm) - Ni (0.6 µm) - Au (2 µm).

The integrated microwave hybrid circuit of the invention operates as follows.

A signal is applied to the input of semiconductor chip 7 and undergoes a suitable conversion, after which the converted signal is extracted from the circuit output. In addition, a quality grounding with small undesirable parameters and a suitable heat dissipation is ensured via metallization of the hole, the electrically conductive and the heat conducting material which fills the hole, the projection of the base and the base itself.

The new integrated hybrid microwave circuit improves its electrical parameters due to the establishment of electrical connections between the chip bonding plants to be grounded and the base projection, which ensures small undesired parameters, while providing better heat dissipation from the most heated chip portion. whereby the manufacturing capability of the circuit is improved due to reduced requirements regarding accuracy in the manufacture of the hole and the projection as well as their alignment during the assembly procedure.

In describing the illustrated embodiment of the present invention, specific limited terminology is used for the sake of clarity. However, the invention is not limited to the specific expressions thus selected and it will be appreciated that each such expression covers all corresponding elements which function in a similar manner and are used to solve the same problem.

Although the present invention has been described herein with reference to the advantageous embodiment, it will be appreciated that various modifications and alterations may occur with regard to structural details without exceeding the scope and scope of the invention, as will be readily apparent to those skilled in the art.

WSPBWOL3 \ users \ FM \ DOC \ Word doc \ P33585-B.doc

522 106 '^^ί··'^:’·^;:·^ί

All these modifications and modifications should be considered to be within the limits of the invention idea and framework and within the limits of the requirements that follow.

INDUSTRIAL APPLICABILITY The present invention can be used in semiconductor microelectronics.

SPBWOL3 \\ \ users \ FM \ DOC \ Word doc \ P33585-B.doc

522 106