JPH01266786A - Construction of conductor of hybrid integrated circuit and its manufacture - Google Patents

Abstract

PURPOSE:To facilitate formation of a conductor with a large current capacity and reduction of the circuit size by forming conductors with different thicknesses, i.e. different current capacities, on the same substrate. CONSTITUTION:A copper foil 3 is bonded to one of the main surfaces of a substrate 1 and the thickness of the copper foil 3 is made to be equal to the thickness(t) of a conductor 6 for a large current. Then the predetermined region of the copper foil 3 is, for instance, half-etched to make the thickness of that region equal to the thickness(t1) of a conductor 7 for a small current. Then, the conductor 6 for a large current is formed in the large current region 4 with the thickness(t) and the conductors 7 for small currents are formed in the small current region 5 with the thickness(t1) by etching. With this constitution, the difference in conductor width between the large current conductor and the small current conductor can be reduced and high density conductor patterns can be formed to cause a large current to flow to the conductor 6; further, the circuit size can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a conductor structure of a hybrid integrated circuit in which conductors for large current and small N6E are formed on the same substrate, and a method for manufacturing the same.

(B) Prior Art A hybrid integrated circuit typically has a predetermined conductor formed on a substrate, and a plurality of semiconductor elements fixed onto the conductor.

In addition, in a hybrid integrated circuit made of a metal substrate, when a conductor pattern with a large current capacity and a conductor pattern with a small current capacity are formed on the same substrate using 01 foil, the conductor (11) is usually used as shown in FIG. The current capacity is determined by the width of the copper foil (the thickness of the copper foil at this time is constant).

(c) Problems to be Solved by the Invention When a conductor with a large current capacity and a conductor block with a small current capacity are required on the same substrate, when forming the conductor with a large current capacity, as shown in FIG. The only method available is to increase the width of the copper foil, which poses problems in terms of reducing the mounting area of the board and miniaturizing the hybrid integrated circuit.

Also, if you try to reduce the pattern area by increasing the copper foil thickness for a conductor with a large current capacity, the copper foil thickness remains constant, so it is possible to form a fine pattern with a conductor block with a small current capacity. However, there is a problem in that the mounting area of the board becomes smaller.

(d) Means for solving the problems The present invention has been made in view of the above-mentioned problems,
As shown in the first diagram, it is equipped with a hybrid integrated circuit board and a plurality of conductors formed from copper foil stuck on the board, and the film thickness of the conductors is selectively adjusted according to the size of the current capacity. Recognize the difference and resolve it.

(E) Effect As described above, according to the present invention, the film thickness of the conductor is made different for large currents and small currents, that is, the film thickness for large currents is thicker and the film for small currents is thinner. By doing so, it is possible to reduce the difference in the width of the conductor for large and small currents and form a high-density conductor pattern, and it is possible to flow a large current through the conductor for large currents as in the conventional case.

(F) Examples The present invention will be described in detail below based on the examples shown in the drawings.

The first diagram is an enlarged perspective view of the main part showing the conductor structure of the hybrid integrated circuit of the present invention. The conductor (2) for large current and small current formed is an insulating resin layer having adhesive properties for bonding the substrate (+) and the copper foil.

Next, a method for manufacturing a hybrid integrated circuit according to the present invention will be explained. First, as shown in FIG. 1A, a hybrid integrated circuit board 1) is prepared. The hybrid integrated circuit board (1) may be made of metal, ceramic, glass evo, etc., but a metal aluminum board is used because it can easily dissipate the heat generated by the copper foil. The surface of the aluminum substrate (1) is insulated by anodic oxidation, which is a well-known technique. A copper foil (3) of a desired thickness is adhered to the main surface of the hybrid integrated circuit board (1). The copper foil (3) is adhered to the substrate (1) via an insulating resin layer (2) such as an epoxy resin having adhesive properties.

At this time, the thickness of the copper foil (3) is made the same as that of the conductor for large current.

Next, as shown in FIG. 1B, the thickness of the copper foil (3) is varied in predetermined areas of the copper foil (3). By varying the thickness of the copper foil (3), the thick area can be increased by 1! Diversion, use thin area for small current. That is, an etching resist is applied to the area where the conductor for large current is to be formed, and only the area where the conductor for small current is to be formed is partially herbal etched. The depth of the partial etch in the area where the low current conductor is to be formed is up to the surface thereof where the low current conductor is to be formed. That is, in pattern design, the film thickness of conductors for large and small currents is 1, 1, . can be set individually, so it is only necessary to etch by the difference (t-t+).

In this example, the conductor regions for large current and small current will be divided into regions (4) and (5), but there is no need to separate conductor regions for large and small currents, and they can be formed randomly. .

Next, as shown in Figure 1C, a photosensitive resist is applied onto the copper foil (3) with different film thicknesses in the large and small current regions (4) and (5) using a one-way spray method, a dip coater method, a roll coater method, etc. Then, the desired pattern of the conductors (6) and (7) for large N, current, and small current is exposed and developed (hatched area).

Next, as shown in the first diagram, when the copper foil (3) is etched, a large current conductor (6) is formed in the large current area (4) with a film thickness of t.
However, the film thickness is 1. A conductor for small current (7) is placed in the small current region (5) of
) is formed.

Although not shown, heat-generating semiconductor elements such as power transistor ICs and LSI chips are firmly fixed on one thick conductor, and chip capacitors, chip resistors, and small signal devices are placed on the other thin conductor. A non-heat generating semiconductor element such as a transistor is fixed.

The manufacturing method described above is effective when there is not much difference in film thickness between the conductors (6) and (7). ) is not applicable in this case. A manufacturing method in which the film thickness is significantly different will be described below.

The process until the copper foil is pasted on the board is the same as described above, and the explanation will be omitted.

As shown in Figure 2A, there is an insulating resin layer (2) on the substrate (1).
) A copper foil (3) of a desired thickness is attached through the film.

The thickness t of this copper foil (3) is set to the thickness of the large current conductor. After pasting the copper foil (3) on the substrate (1), a photoresist for etching is applied to the entire surface of the copper foil (3), and a conductor pattern for high current is exposed and developed. Resist is then left only on the high current conductor (shaded area).

Next, as shown in FIG. 2B, the copper foil (3) is etched. The etching depth at this time is the surface of the small current conductor, that is, the film thickness is 1. Do it until. After that, copper foil (3) again
Apply a photolith for etching to the entire surface, and expose the pattern of the small current conductor and large current conductor (6).
After developing and leaving the resist only on the area that will become the small current conductor (7) and the large current conductor (6) (hatched area), as shown in Figure 2C, the thickness of the exposed copper foil is 1. ．． By etching deeply, as shown in the second diagram, conductors with different current capacities can be formed on the same substrate (1)-H even if there is a significant difference in the current capacities of the respective conductors (6) and (7). can do. Note that when applying photoresist on the large current conductor (6), it is preferable to remove the initial resist.

If the above-mentioned etching process is repeated, large and
It is also possible to form conductors for medium and small currents, that is, conductors corresponding to hyperactivity in current capacity.

According to the present invention, conductors with different current capacities can be selectively formed on the same substrate, so conductors with different current capacities can be formed without changing the size of the substrate. be able to.

(G) Effects of the Invention As detailed above, according to the present invention, conductors with different film thicknesses, that is, conductors with different current capacities can be formed on the same substrate. A conductor with a large capacity can be formed, and a hybrid integrated circuit can be easily miniaturized.

Furthermore, the present invention has the advantage that it can be manufactured using conventional manufacturing processes as they are.

[Brief explanation of the drawing]

1A to 1D are perspective views showing a method for manufacturing a conductor for a hybrid integrated circuit according to the present invention, FIGS. 2A to 2D are perspective views showing another manufacturing method, and FIG. 3 is a perspective view showing a conventional method. FIG. (1)...hybrid integrated circuit board, (2)...insulating resin layer, (3)...copper foil, (4)(5)...large and small current region, (6)(γ). ··conductor.

Claims (10)

[Claims] (1) It comprises a hybrid integrated circuit board and a plurality of conductors formed from copper foil stuck on the board, and the film thickness of the conductors is selectively varied according to the size of current capacity. A conductor structure of a hybrid integrated circuit characterized by: (2) The conductor structure of a hybrid integrated circuit according to claim 1, wherein the conductor is divided on the substrate according to the magnitude of the current capacity. (3) The conductor structure of a hybrid integrated circuit according to claim 1, wherein the conductors having different film thicknesses are used for large current and small current. (4) After adhering a copper foil of a desired thickness to one main surface of a hybrid integrated circuit board and varying the thickness of the copper foil in a predetermined region of the board, each of the copper foils having a different thickness A method for manufacturing a conductor for a hybrid integrated circuit, comprising selectively forming conductors having different thicknesses on the same substrate by etching a foil. (5) Predetermined areas of the copper foil are partially etched to make the thickness of the copper foil different.
A method of manufacturing a conductor for a hybrid integrated circuit as described. (6) The method of manufacturing a conductor for a hybrid integrated circuit according to claim 4, wherein the etching step is performed at least once. (7) The method of manufacturing a conductor for a hybrid integrated circuit according to claim 6, wherein the etching step is carried out from the maximum thickness of the conductor to the surface of the next thickness. (8) The method of manufacturing a conductor for a hybrid integrated circuit according to claim 4, wherein the conductors having different film thicknesses are formed by dividing the conductors into predetermined regions on the substrate. (9) The conductor structure of a hybrid integrated circuit and its manufacturing method according to claims 1 and 4, wherein the steel foil is bonded with an insulating resin having adhesive properties. (10) The conductor structure of a hybrid integrated circuit and its manufacturing method according to claims 1 and 4, wherein the hybrid integrated circuit board is an insulated metal substrate.