DE7628700U1 - Electronic assembly - Google Patents

Description

The innovation concerns a hybrid electronic assembly with integrated puncture elements such as inductors and capacitors and resistors and possibly also other functional elements that are made using thin-film technology.

Especially in the frequency range from about 1 to 1000 MHz, circuits are required for many purposes, which are essential functional components ττιΛην + .- ϊvities. Include capacitances and ohmic resistances and in numerous cases also with semiconductor components, e.g. transistors, semiconductor circuits, diodes or special components, such as NTC thermistors or the like should be able to be equipped.

The known electronic RF assemblies are either entirely equipped with individual components or networks are used in some cases, which at most two of the three most often required passive functional element types, namely inductances, capacitances and ohmic resistances, in integrated form.

The present innovation is based on the task of a hybridizable or to create any other electronic assembly of the type mentioned, that is, an assembly that the Contains inductances, capacitances and resistances integrated,

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can be equipped with semiconductor components or special components and additionally, if necessary, others implemented using thin-film technology Functional elements such as capacitors. This electronic assembly should be able to be produced with little effort be, have a high operational reliability and optimally meet the functional conditions placed on them.

To solve the given task, see the 'innovation in a Electronic assembly of the type mentioned above, a laminate as the base material, consisting of at least a single-layer Plastic foil with metal foil, e.g. copper or aluminum foil applied on both sides, at least about 5 µm thick, which may be used. each with thin layers of plastic and / or metal on both sides are provided, from whose individual foils and layers the conductor, connection and functional elements are worked out.

The resistances and capacities of this assembly are for example-ωβ-iκ « adjustable with a laser. The semiconductor and special components are simple and inexpensive embodiments reliably hybridizable or usable in other ways. Because the electronic assembly and in particular that for its manufacture The laminate serving is extremely advantageous, the largely automatic production of the assembly is possible. Inside There are only a few soldering points on the assembly, which is of great benefit to the operational reliability of the assembly. The fourth range for the inductances of the assembly extends to to several / UH, for capacities up to some 10 nF and for the resistors up to fourth over 100 kOhm.

In terms of manufacturing technology, the combination of the thin layers has proven itself extremely difficult with the relatively thick plastic and metal foils.

This difficulty is solved if first on the metal foils the thin dielectric and metallic resistance

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Electrodes and adhesive layers applied, then those coated in this way Copper foils are hot-pressed with the plastic film, the copper structures, the conductor tracks and electrodes are etched out and finally the resistors are carved out of the thin metallic layers, i.e. e.g. also etched or can be carved out by a laser.

At least one of the two copper foils to be laminated is used as a carrier material for the resistance layer, e.g. chemically deposited or as a Crlii layer - selectively if required - is vaporized onto the copper foil.

To form a capacity, i.e. a so-called Thin film capacitor on at least one of the two copper foils, this is in the area of the desired capacitance elements before it is pressed provided with a dielectric layer and, in relation to this, with a shifted area in terms of area with a metallic layer. By the later Etching of the copper foil then results in the electrode facing away from the plastic foil, whereby the electrode applied to the copper foil, E.g. evaporated, thinner electrode is protected from the effects of etching by the dielectric.

The innovation is explained in more detail below with reference to the drawing. It shows:

Fig. 1 is a plan view of an electronic assembly according to the innovation in a schematic representation, with for the metal coverage For example, copper is used, Fig. 2 shows a section along the line II-II of FIGS. 1 and 3 and 3 shows a view from below of the electronic assembly according to FIG.

The electronic assembly according to FIGS. 1 to 3 has a single or multilayer plastic film 1, for example made of polyimides and the like. or from thermoplastic polytetrafluoroethylene or a combination of both materials. To achieve a possible

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large area capacity, the thickness of a plastic film is preferably chosen not to be too great. Thicknesses of about 10 to 50 μm have proven to be suitable. The copper foils arranged on both sides of the plastic foil 1 and hot-pressed with it are made up of structures such as connection pads 5, flat coils 6, 7 ¹ , 7 ", capacitor electrodes 8 ', 8", 9 », 9", conductor tracks 11 and electrodes 14 for thin-film capacitors worked out, especially etched out. The flat coil 7 ¹ is magnetically closely coupled to the flat coil 7. The plastic film 1 acts as a dielectric for the capacitors with the electrodes 8 ', 8 "and 9'>9". According to FIG. 3, the capacitor has the electrodes 9 ', 9''a partial electrode 9''' with lower conductivity, which can be removed in the desired area for balancing this capacitor with a laser Side a dielectric layer 15 and a thin-film electrode ^{16. The thin-film electrode 16 is conductively connected to the capacitor electrode 9 1.}

On the side facing the plastic film underside of the A resistor 13 meandering with a laser or by etching, for example an MCr layer, is applied to a copper foil, for example by vapor deposition. Their sheet resistance is preferably about 50 to 200 ohms. In special cases, smaller or larger surface resistance values can also be used be desirable.

To improve the adhesion between the copper foils and the plastic film 1, an adhesive layer 17, e.g. an M, FeNi or a CrNi layer of extremely small thickness. Using a CrNi layer as an adhesive and resistance layer both layers can be applied simultaneously in the same vapor deposition device. If the layer is thin enough the adhesive layer has so little electrical conductivity that it is not removed separately from the copper-free surfaces of the plastic film 1

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must become.

The optimal thickness of the copper foils and thus of the structures worked out, especially etched out, from these foils depends on the operating frequency area and is the lower the higher it is. In general, the thickness of the copper foils should be a multiple of the skin penetration depth, above all when you want to implement inductors with high quality factors. It is not necessary here that the two copper foils have the same strength.

A component applied in hybrid technology and not shown in the figure is indicated by 10. The vias 12 are designed in the usual way.

The resistor 13 and - as already mentioned - the capacitors with the capacitor ^{electrodes 9 ″ r} or 16 can preferably be adjusted by means of a laser the foil circuit or on the laminate itself find the counter-support or in an additional housing that partially or completely encloses the electronic assembly.

If a laminate is used in which at least one of the two copper foils is thinner than approximately 40 μm, a copper structure which enables direct contact, e.g. soldering in of bare semiconductor chips. The copper coverings stay on the plastic film, the nature and small thickness of which is elastic enough »to create a reliable connection to guarantee.

9 claims for protection
3 figures

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Claims (7)

Protection claims 1. Hybridable electronic. Assembly with integrated functional elements such as inductances, capacitances and resistances and possibly with functional elements in thin-film technology, characterized by a laminate as the base material, consisting of an at least one-layer plastic film with metal foils at least 5 μm thick applied on both sides, which are optionally covered on both sides with thin layers of plastic and / or metal, from its individual Foils and layers the conductor, connection and functional elements are worked out. 2. Electronic assembly according to claim 1, characterized in that that a film made of different layers is provided as a plastic film. 3. Electronic assembly according to claim 1, characterized in that g e that as the dielectric of a capacitor, the plastic film and as its electrodes at least partially congruent areas of the opposing metal foils are provided. 4. Electronic assembly according to claim 3 »characterized that one of the electrodes of the capacitor has an area which can be removed by means of laser beams. 5. Electronic assembly according to claim 1, characterized in that that at least one thin-film capacitor is arranged on one side surface of the plastic film consists of an electrode carved out of the copper foil and a dielectric applied to it and a counter electrode applied to the dielectric. 7628700 06/16/77 - · "- · III Il tele C t 6th electron! a before subassembly na ob. Claim 1, characterized in that on the side surface of the plastic material opposite a resistor, a v / heat dissipating
Me'uallbelag is arranged. 7. Electronic assembly according to claim 1 * characterized in that that on the side surfaces turned towards the plastic P ^ iie the! metal foil adhesive layers, in particular M, -, CrUi layers, are applied. 7628700 06/16/77