DE202005021556U1 - Soluble electrically conductive material based on functional saccharides and metallic particles - Google Patents

Abstract

electrical conductive material mixtures of functional saccharides and metallic particles, which are characterized in that functional saccharides and metallic particles have a defined electrical form conductive material or electrical resistance, the invention is a new substance.

Description

Subject of the invention

The The invention relates to a releasable electrically conductive Material or material mixture based on functional saccharides and metallic particles. This conductive material mixture especially for gluing semiconductor elements, for manufacturing electrically conductive contact and connection points, for Creation of tracks or resistive layers to not conductive pad used by conventional printing techniques become. The material mixture hardens without any special heat treatment by UV or hot air and is diluted with Acids dissolvable or correctable. simultaneously can the material mixture for mirroring or electrical shielding of ceramic materials or glass materials or polymer materials be used and their surface conductive or made contactable.

State of the art

By the rapid development of micro- and polymer electronics is intensified looking for alternatives for soldering materials. These Alternatives should be comparable in application, such as conventional soldering materials, but less critical Have processing properties.

When especially the processing temperatures are critical. Not infrequently, temperatures of over 230 ° C needed for soldering. It is especially difficult the dissolution of the solder joint, because itself In this process, the semiconductor elements to temperatures of over 230 ° C can heat up. The limited constructive possibilities of the components and Material selection. After such a desoldering process are the sensitive semiconductor elements and their neighboring components often no longer useful and must be replaced. films and thermoplastic boards can therefore usually not be used.

When Alternatives have become more and more electric in recent years conductive pastes based on polymers, electrically conductive Particles and solvents. Benefits of this are one mostly lower processing temperature and one for semiconductor technology Gentle curing by crosslinking via UV irradiation or low temperature increase. Disadvantage is an irreversible Compound, because the polymer cross-links with the base material and only can be solved with mechanical destruction.

As in the patent DE 10 228 484 A conductive adhesive of epoxy resins, metal particles and organic solvents is presented, whose electrical properties are similar to those of metals. The disadvantage is that the created connections of semiconductor element and electrical connection point can not be reversibly solved. For tests in the electronic industry, it is advantageous if not optimal electrical components can be reversibly solved and replaced undamaged. This would have a big economic advantage.

In the patent DE 3 809 331 is described a screen-printable, electrically conductive paste consisting of an electrically conductive metal powder, an organic resin and an organic solvent. The described conductive paste retains its electrically conductive properties largely under mechanical stress, but also performs as in DE 10 228 484 to irreversible compounds that can not be solved nondestructively.

In the patent JP 2003 168 976 describes an electrically conductive paste based on electrically conductive metal particles, cellulose derivatives, fatty acids and a solvent. Also, this paste results in an irreversible connection that can not be solved nondestructively.

Objects of the invention

Building on the above-mentioned findings, it was an object of the invention, an electrically conductive, flowable Paste using functional saccharides and metal particles or intrinsically reduced metal particles found in the liquid and solid state metal particles on different surfaces fixed so that they are good current permeable at low resistance are and have a high thermal conductivity. The paste is intended to be both permanent or temporary components fix, d. H. These must be complete and undamaged be removable if necessary. The undamaged replacement of the Components is a particular advantage in recycling and reuse of used components.

The Task was solved in such a way that as a first subtask Polymers, oligomers or monomers were sought, which are the metal particles good tie and an electrophysical and or electrochemical Make contact. It was found that both bipolar polymers, such as. As polyaminoglucose, as well as monomeric Glucoseamin (-Monoaminoglucose-) are very suitable. Their resistances or conductivities were measured and optimal monomer, Oligomer, polymer blends found.

As a second sub-task, the interactions of resistance, viscosity and dry were investigated and the optimum mixture of particle size and quantity, and determined proportion of the required amount of liquid.

When third sub-task raises the question of the optimal liability the flowable conductive paste on the ground and the components to be bonded, which by tensile and shear tests can be determined.

The fourth subtask results from the selection of suitable combinations for different uses. So should a trace the property of low resistance at low cross section and heat generation while having a contact point The requirement is optimal adhesion with low resistance depending on mechanical loads, temperature changes and change the humidity.

The The fifth sub-task was the production of the detachable ones Adhesive bonds that are as possible without the influence of temperature, the replacement of defective components without undamaged Components and possibly the thinnest polymer carrier layers to harm.

The sixth subtask was, simultaneously with the production of conductive Surface to produce a mirror coating, so z. B. Glass fibers can be electrically and optically coupled simultaneously or conductor tracks made on ceramic or other substrates can be.

To Solution of these subtasks should be with as possible known technologies of conductive adhesive on surfaces in applied to micro- and nanostelligen area, detached or can be corrected.

The Inventive breadth of these subtasks is very complex. Therefore in the patent only the general solutions and their breadth of variation demonstrated.

detailed solutions are explained as an application example.

The Tasks are according to the claims 1 to 5 and 12 solved. The further embodiment of the invention results from the claims 2 to 11 and 13 bis 17th

To illustrate the invention, further embodiments are to be made:
According to the new electrically conductive material mixture, this is based on the combination of functional saccharides and metallic particles in a pure mass ratio of functionalized saccharides to metallic particles between 5: 1 to 1: 1000.

According to the new electrically conductive material mixture comes as a functional Saccharide, preferably polyaminoglucose with a degree of deacetylation from 50 to 99.9%, with a viscosity of 200 mPas up 10000 mPas and an ash content of 0.1 to 7%, oligoaminoglucose with a degree of deacetylation of 50 to 99.9%, with a viscosity from 10 mPas to 200 mPas and an ash content of 0.1 to 7% and Glucoseamine with an ash content of 0.1 to 7% for use. Prefers becomes polyaminoglucose with a degree of deacetylation of 80 to 92%, with a viscosity of 800 mPas to 4000 mPas and a Ash content of 0.1 to 3%, oligoaminoglucose with a degree of deacetylation from 80 to 92%, with a viscosity of 75 mPas to 150 mPas and an ash content of 0.1 to 3% and monoaminoglucose with used an ash content of 0.1 to 3%.

The according to the new electrically conductive material mixture used functionalized saccharide, thus consists of polymers or an oligomeric portion or combinations of polymers and Oligomers with or without the addition of monomers. The proportional composition of polymers, oligomers and monomers is in the range 1: 0: 0, 1: 0.05: 0 to 1: 50: 0, 1: 0: 0.05 to 1: 0: 50, 0: 1: 0.05 to 0: 1: 50 and 1: 0.05: 0.05 to 1:50:50.

According to the new electrically conductive material mixture come as metallic Particles preferably copper, silver, platinum, nickel, lead, zinc, tin and their homologues are used. Their particle size should be in the range of 30 nm to 200 μm, preferably in Range from 200 nm to 500 nm. Also mixtures of different Particle sizes are desired.

The intimately mixing the main components to achieve the new electrical Conductive material may preferably by stirring in Solution, kneading, rolling and / or extrusion carried out. When stirring in solution, the concentration of solids should be relative be low. It should be between 1 to 20 parts, preferably 4 to 8 parts, based on the solvent, which is preferably Water is, lie. In the other variants of intensive mixing the proportion of solvents can be significantly lower. The proportion of solids can here between 10 to 80 parts, preferably between 40 and 70 parts, based on the solvent, which is preferably water, lie. A warming The mass during the mixing process intensifies the mixing and accelerates homogenization. The maximum temperature may be should not be higher than 220 ° C, preferably should they are between 60 ° C and 120 ° C.

Next the main components (functionalized saccharides and metallic Particles) can still property-improving components on the processing of the new electrically conductive material to be added:

Property-improving component K1

to Increasing flexibility and improved Bonding is recommended, polyvinyl acetate or polyvinyl alcohol, as well as in combination collagen, gelatin and / or rubber of 0.5 to 100 parts, based on the sum of functionalized Saccharides to metallic particles, attach.

Property-improving component K2

Around to further increase flexibility, recommends it is a nitrogen-containing auxiliary, preferably urea, or its derivatives such. N, N-dimethylurea or dimethylacetamide between 0.1 to 10 parts, based on the sum of functionalized Saccharides to metallic particles, attach.

Property-improving component K3

to Increasing the flowability can be a plasticizer be added in the proportion between 0.1 and 25 parts. The plasticizers used are preferably glycerol, ethylene glycol or polyethylene glycol in the Proportion between 0.5 to 10 parts or dicarboxylic acid ester medium chain length, such as diethyl adipate in the proportion between 0.5 and 15 parts, based on the sum of functionalized saccharides to metallic particles, to attach.

Property-improving component K4

For Homogeneity improvement can be organic Acids, preferably stearic acid, ascorbic acid and / or longer chain dicarboxylic acids such as adipic acid and / or oxalic acid as well as modified waxes and / or Polyphosphates, preferably sodium polyphosphate, as additives in the proportion of 0.1 to 10 parts, based on the sum of functionalized Saccharides are added to metallic particles.

Property-improving component K5

Around hydrophobize the new electrically conductive material, it can with alkali silanes, alkali hydrides, waxes, preferably with acrylic acid-modified waxes, and / or resins, preferably anionic, in the proportion of 0.1 to 20 parts on the sum of functionalized saccharides to metallic Particles, mixed and / or coated.

Property-improving component K6

The Solubility of the compound can be increased when 1-20 parts of a salt (preferably acetate) are added is used to control the hydrophilic properties.

Property-improving component K7:

If the metal particles react to electrical and / or magnetic fields a field can be created below the contact area, which causes the metal particles to adhere to the contact surface concentrate and the adhesive becomes hydrophobic on the predominantly metallic depositing conductive layer and this can electrically isolate.

• – Elektrisch leitfähige Pasten
• – Pasten mit definiertem spezifischen Widerstand
• – Elektrisch leitfähige lösbare Kleber
• – Druckbare elektrisch leitfähige Flüssigkeit zur Herstellung von Leiterbahnen
• – Label, Prüf- und Kontrollmarken
• – Biochips
• – Antistatikverpackungen
• – Beschichtete Glasfasern zur Erhöhung der Verspiegelung bei gleichzeitiger elektrischer Leitfähigkeit der Ummantelung
• – Keramikbauelemente mit elektrisch leitenden Strukturen, die abhängig sein können von Temperatur und Luftfeuchte
• – Elektrisch leitende Strukturen auf Zellulose-, Textil- und Folienunterlagen

From the mixtures prepared in the manner described above, it is possible to produce electrically conductive structures or resistance layers of high quality and to produce, by means of known techniques, inter alia the following products:

• - Electrically conductive pastes
• Pastes with defined resistivity
• - Electrically conductive removable adhesive
• - Printable electrically conductive liquid for the production of printed conductors
• - Label, test and inspection stamps
• - biochips
• - Anti-static packaging
• Coated glass fibers to increase the silvering with simultaneous electrical conductivity of the sheath
• - Ceramic components with electrically conductive structures that may be dependent on temperature and humidity
• - Electrically conductive structures on cellulose, textile and foil underlays

The The following examples illustrate the subject matter of the invention.

example 1

Preparation of an electrically conductive paste of polyaminoglucose, oligoaminoglucose, monoaminoglucose, copper metal particles and oxalic acid:
The paste is made by means of a commercial Heizrührplatte in a beaker. For this purpose, 100 ml of a 4% polyaminoglucose, 100 ml of a 5% oligoaminoglucose solution and 100 ml of a 6% Monoaminglocoselösung heated to 65 ° C with stirring. Then 3 g of oxalic acid are added and stirred at 65 ° C for 5 minutes. Thereafter, 150 g of copper metal particles are added and heated to 75 ° C. After stirring for about 30 minutes, the mixture is homogeneous and can be used after cooling as an electrically conductive paste.

Example 2

Preparation of an Electrically Conductive Adhesive Made of Polyaminoglucose, Monoaminoglucose, Silver Metal Particles, Polyvinyl Alcohol and Oxalic Acid
The adhesive is made by means of a commercial Heizrührplatte in a beaker. For this purpose, 100 ml of a 4% polyaminoglucose, 100 ml of a 6% Monoaminglocoselösung and 100 ml of a 10% polyvinyl alcohol solution are heated to 65 ° C with stirring. Then 2 g of oxalic acid are added and stirred at 65 ° C for 5 minutes. Thereafter, 100 g of copper metal particles are added and heated to 75 ° C. After stirring for about 45 minutes, the mixture is homogeneous and can be used after cooling as electrically conductive adhesive.

Example 3

Preparation of a Printable Electrically Conductive Liquid for the Production of Printed Circuits from Oligoaminoglucose, Monoaminoglucose, Copper Metal Particles, Glycerol and Urea
The printable electrically conductive liquids for the production of printed conductors are produced by means of a commercial Heizrührplatte in a beaker. To this end, 100 ml of a 4% polyaminoglucose solution, 100 ml of a 6% monoamine glucose solution and 100 ml of a 20% glycerol solution are heated to 65 ° C. with stirring. Then, 2 g of urea are added and stirred at 65 ° C for 5 minutes. Thereafter, 70 g of copper metal particles are added and heated to 75 ° C. After stirring for about 20 minutes, the mixture is homogeneous and can be used after cooling as a printable electrically conductive liquid for the production of printed conductors.

Example 4

Preparation of antistatic packaging of polyaminoglucose, silver metal particles, polyvinyl alcohol and glycerol:
The antistatic packaging is made by means of a commercial Heizrührplatte in a beaker. For this purpose, 100 ml of a 1% polyaminoglucose solution and 100 ml of a 15% polyvinyl alcohol solution are heated with stirring to 65 ° C. Then, 100 ml of a 1% glycerol solution are added and stirred at 65 ° C for 5 minutes. Thereafter, 1.6 g of silver metal particles are added and heated to 75 ° C. After stirring for about 10 minutes, the mixture is homogeneous and can be given for setting in a cast film mold. After about two days, the film is dried and can be used as an antistatic packaging.

Example 5

Preparation of Hydrophobicized Electrically Adhesive Adhesives from the Adhesive Produced from Example 2
The adhesive is further processed directly, in which 1 ml of acetic anhydride is added at intervals of 1 second and held at 80 ° C for 5 min. Then 10 ml of 99% ethanol are added quickly and stirred vigorously for a further 10 minutes while cooling. Thereafter, the aqueous phase can be separated and the residue processed as a hydrophobized electrically conductive adhesive.

Example 6:

Of the Glue can also, as Example 4 for coating glass, glass fibers or ceramics are used, either for mirroring as conductive outer shell or for application of traces on ceramic elements, eg. B. for metrological Purposes.

Example 7:

manufacturing a conductive adhesive according to Example 1-5 and Applying a magnetic field to the underside of the carrier to align the metal particles. By applying a voltage from 0.1 to 220V at the end points of the trace becomes the contact the metal particle accelerates.

Example 8:

manufacturing a conductive adhesive and drying of the adhesive or Reduction of the polysaccharide structure to pure carbon compound by driving over the lead structure with a laser under anaerobic or aerobic conditions.

• – Kostengünstige Herstellung
• – Verbesserte Umweltverträglichkeit der erhaltenen Werkstoffe
• – Die Eigenschaften der Werkstoffe können durch Veränderung der Zusammensetzung in weiten Bereichen zielgerichtet beeinflusst werden
• – Die elektrische Leitfähigkeit kann mit denen reiner Metalle verglichen werden.
• – Einstellungsmöglichkeit der lösbaren oder nichtlösbaren Eigenschaften

The materials thus produced have the following advantages:

• - Cost-effective production
• - Improved environmental compatibility of the materials obtained
• - The properties of the materials can be influenced in a targeted way by changing the composition
• - The electrical conductivity can be compared with those of pure metals.
• - Setting possibility of the detachable or non-detachable properties

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10228484 [0005, 0006]
• - DE 3809331 [0006]
• JP 2003168976 [0007]

Claims (16)

Electrically conductive material mixtures of functional saccharides and metallic particles, which are characterized in that functional saccharides and metallic particles form a defined electrically conductive material or electrical resistance, which according to the invention is a new substance. Electrically conductive materials made of functional Saccharides and metallic particles according to claim 1, characterized characterized in that as functional saccharides preferably polyaminoglucose, oligoaminoglucose and monoaminoglucose can be used. Electrically conductive materials made of functional Saccharides and metallic particles according to claim 1, characterized characterized in that according to the new electric conductive material used functionalized saccharide from Polymers or an oligomeric moiety or combinations of polymers and oligomers with or without the addition of monomers, with a ratio of polymers, oligomers and monomers of 1: 0: 0, 1: 0.05: 0 to 1: 50: 0, 1: 0: 0.05 to 1: 0: 50, 0: 1: 0.05 to 0: 1: 50 and 1: 0.05: 0.05 to 1:50:50 is used. Electrically conductive materials made of functional Saccharides and metallic particles according to claim 1, characterized characterized in that as polyaminoglucose chitosan with Deacetylierungsgraden between 50 and 99.9% and viscosities from 200 mPas to 5000 mPas and ash contents of 0.1 to 7% are used. Electrically conductive materials made of functional Saccharides and metallic particles according to claim 1, characterized characterized in that as oligaminoglucose chitosan with Deacetylierungsgrade between 50 and 99.9% and viscosities from 50 mPas to 200 mPas and ash contents of 0.1 to 7% are used. Electrically conductive materials made of functional Saccharides and metallic particles according to claim 1, characterized characterized in that as monoaminoglucose glucoseamine with a Ash content of 0.1 to 7% is used. Electrically conductive materials made of functional Saccharides and metallic particles according to claim 1, characterized characterized in that as metallic particles copper, silver, platinum, Gold Nickel and iron and their homologues with a particle size of 50 nm to 200 microns are used. Electrically conductive materials made of functional Saccharides and metallic particles according to claim 1, characterized characterized in that the metallic particles from the solution supplied metal salts intrinsically by chemical reaction be formed. Electrically conductive materials made of functional Saccharides and metallic particles according to claim 1, characterized characterized in that the metal particle reduction by added Reducing agent is accelerated. Electrically conductive materials made of functional Saccharides and metallic particles according to claim 1, characterized characterized in that used as saccharides chitosan derivatives in particular carboxylmethyl chitosan and chitosan lactate. Electrically conductive materials made of functional Saccharides and metallic particles according to claim 1, characterized characterized in that the ratio of functional saccharides to metallic particles is between 5: 1 to 1: 1000. Electrically conductive materials made of functional Saccharides and metallic particles according to claims 1 to 9, characterized characterized in that to increase flexibility and for improved adhesion, polyvinyl alcohol or polyvinyl acetate, such as also in combination collagen, gelatin and / or rubber of 0.5 to 100 parts, based on the sum of functionalized saccharides to metallic particles, are used. Electrically conductive materials made of functional Saccharides and metallic particles according to claims 1 to 10, characterized characterized in that in order to further increase flexibility, a nitrogen-containing auxiliary, preferably urea, or its derivatives such as As N, N-dimethylurea or dimethylacetamide between 0.1 to 10 parts, based on the sum of functionalized saccharides to metallic particles, is used. Electrically conductive materials made of functional Saccharides and metallic particles according to claims 1 to 11, characterized characterized in that to increase the flowability Plasticizer in the proportion between 0.1 and 25 parts, preferably glycerol, ethylene glycol or polyethylene glycol in the proportion between 0.5 to 10 parts or Medium chain dicarboxylic acid esters, such as diethyl adipate in the proportion between 0.5 to 15 parts, based on the sum of functionalized Saccharides are added to metallic particles. Electrically conductive materials of functional saccharides and metallic particles according to claim 1 to 12, characterized in that to improve the homogeneity of organic acids, preferably stearic acid, ascorbic acid and / or longer-chain dicarboxylic acids such as adipic acid and / or oxalic acid as well as modified waxes and / or polyphosphates, preferably sodium polyphosphate, as additives in the proportion of 0.1 to 10 parts, based on the total from functionalized saccharides to metallic particles. Electrically conductive materials made of functional Saccharides and metallic particles according to claims 1 to 13, characterized characterized in that the hydrophobing of the electrically conductive Material of functional saccharides with alkali silanes, alkali hydrides, Waxes, preferably waxes modified with acrylic acid, and / or resins, preferably anionic, in the proportion of 0.1 to 20 parts, based on the sum of functionalized saccharides to metallic particles, mixed and / or coated.