JP2002512278A - Adhesive sealing material with flux properties - Google Patents

Abstract

  (57) [Summary] When connecting an electrical component to an electrical terminal on the component-carrying substrate by a solder bump method, a thermosetting adhesive composition for sealing is used, wherein the composition contains a thermosetting polymer and a chemical crosslinking agent, Crosslinkers have flux properties, but do not react with the polymer without heat and / or catalysis or show only a tightly regulated reactivity. The composition can be thermoset when heated to the soldering temperature in a reaction catalyzed by the metal oxide that dissolves from the metal surface by the crosslinking agent and then dissolves in the thermosetting polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to an electrical connection method in an electronic circuit configuration, and more particularly, to a method for attaching a flip chip, a bare semiconductor and a chip scale package (CS).
Ps) Both sealings. This technique is commonly referred to as underfill technology.

[0002] As described in US Pat. No. 5,128,746, solder bump connection when attaching a chip to an electronic circuit configuration eliminates cost, performance limitations, low productivity and poor space utilization of wire bonds. . As circuit densities increase, the size of circuit boards and assembly components is increasingly shrinking, and so-called flip-chip bonding using solder bumps has proven to be the most suitable technology to meet such demands. ing.

[0003] In the most common form of flip-chip connection, solder bumps are placed at the ends of the integrated circuit that occur when the substrate of the integrated circuit is still in the form of a small wafer or die. Typically, a high melting point alloy such as eutectic Sn / Pb 60/40 or Sn / Pb 3/97, which is known to be used in the IBM C4 process, is used as the solder material. The dies or wafers supporting the integrated circuit are bonded to the substrate, for which purpose the dies or wafers are inverted (hence the term flip-chip). It is a current manufacturing method to put a flux or a solder paste on a substrate. This material promotes the adhesion of the die to the substrate during solder bump reflow. The manufactured assembly parts are reflowed,
Sufficient temperature is applied to melt or collapse the solder bumps (step C4) to form the required connections. Next, flux residues are removed to prevent corrosion of the dies and, importantly, to freely insert underfill resin for subsequent encapsulation of the various semiconductors in the fabricated electronic circuit configuration. There is a need to.

[0004] For this latter purpose, an underfill encapsulating resin is applied around and below the dice after reflow and flux removal. Very small gaps between the dice and the substrate must be completely filled for environmental protection of the device. The filling of this gap relies on the capillary action of the seal between the integrated circuit and the substrate. Filling gaps is extremely time consuming, expensive, and difficult to achieve the desired quality, and has proven to be a generally unreliable technique, especially when using relatively large dies. In addition, the low viscosity of the encapsulant required to ensure capillary action controls the thermal expansion and thermal conductivity by filling the encapsulation resin with a ceramic powder that generally increases the viscosity of the resin Contrary to need. The solution to this problem has been to heat the substrate / component parts first to reduce the viscosity of the underfill encapsulating resin. Since raising the temperature causes the curing mechanism to increase the viscosity at an early stage, the temperature needs to be accurately controlled, and it is difficult to control this step. For these various reasons, currently used underfills are less productive and require more space / equipment.

US Pat. No. 5,128,746 proposes that a flux agent be added to a cross-linking agent containing a sealing resin. Provided on the substrate before being placed. US-A-51287
46 discloses the use of certain strong organic dicarboxylic acids as examples of commercially available fluxing agents. This type of flux sealing resin has three significant drawbacks that degrade interconnect integrity. Free acid remains on the encapsulant after reflow and can attack and corrode metals present, especially on dice or wafers. This problem is exacerbated by the reduced environmental resistance of such adhesive compositions due to the presence of unreacted resin. Since the adhesive composition has relatively low resistance to humidity and moisture, corrosion problems are exacerbated. In addition, the addition of acids of the type described to the epoxy resin adhesive impairs the stability of the adhesive, greatly reduces the pot life and changes the curing properties. This has a significant effect on reliability and processing control.

Finally, salts formed in the flux of the material by the reaction of the metal oxide with the fluxing agent and by including various metals such as tin and lead may have a catalytic effect on the polymer material. This causes premature curing of the polymer before solder reflow.

It is an object of the present invention to provide a perfect curable adhesive that does not suffer from the problem of unreacted acid remaining in the encapsulant material after reflow or the problem of pre-curing of the polymer due to salts formed in the flux. It is an object of the invention.

According to one aspect of the present invention, there is provided a thermosetting adhesive composition comprising: (a) a thermosetting polymer, or a polymerized to produce a thermosetting polymer. The resulting monomer, which is a crosslinkable polymer when subjected to the action of a chemical crosslinker; (b) a chemical crosslinker for the polymer, having a flux property and exhibiting no reactivity; Or a crosslinking agent that exhibits very limited reactivity with the polymer without the action of a catalyst and / or heating, and the composition is heated to a soldering temperature in the presence of a catalyst for crosslinking the polymer with the crosslinking agent. A chemical crosslinker that can be thermally cured during storage and that has storage stability and reaction stability at room temperature in the absence of such a catalyst.

[0009] The crosslinker used in the practice of this invention has a fluxing property so that it can remove oxides from the materials with which it comes into contact, ie dies and metallized substrates, especially solder metals, thereby forming a solder joint. enable. When the crosslinker is present in a sufficient amount, it can completely react with the thermoset polymer and neutralize, ie, react with all reactive sites of the polymer. The design of the adhesive is preferably designed to ensure that there are no residual crosslinkers therein, and therefore generally equimolar amounts of polymer and crosslinker are used. However, excess crosslinking agent is not a problem in the practice of the present invention. Even though the pinholes unavoidable in the resin can normally reach the metal surface and corrode, any excess crosslinker remains trapped in the polymer matrix with the catalyst, and metal corrosion is a problem. Does not. Until the latent reaction catalyst is heated to a temperature that effectively causes the curing of the thermoset polymer by the crosslinking agent, and the temperature at which the crosslinking agent melts and dissolves in the polymer or monomer.
The composition itself is storage and reaction stable.

[0010] Accordingly, the present invention provides a chip underflux that can achieve an overall robust structure that protects an integrated circuit that has been previously solder bumped and then flip-chip connected to a metallized style substrate. A fill and seal adhesive composition is provided. During reflow, the flux achieved with the crosslinker allows metal interconnects to be achieved between the solder bumps and metallized pads on the substrate. The adhesive composition then reacts and cures to provide a non-corrosive and environmentally resistant, fully adherent capsule underfill. The adhesive composition itself is stable, providing long-term storage life at room temperature, typically 20-25 ° C, while maintaining predictable processing characteristics. The adhesive composition provides a method of pre-depositing the underfill and eliminates separate fluxes and cleaning, thereby eliminating the major weaknesses of previously known compositions. The adhesive composition has a CTE, glass transition temperature (Tg) without detracting from the above advantages or without deteriorating the rheological properties required to allow for ease of deposition, for example by syringe donation. , May be varied to optimize the modulus and thermal conductivity. Curing can also be easily accomplished during any suitable heat treatment, for example, during reflow soldering. The underfill may only partially cure after one or several cycles of solder reflow, thus facilitating rework of the device. Full cure is then achieved after a separate cure heat application. Alternatively, if reproducibility is not required, complete cure may be obtained from one or two reflow cycles.

Accordingly, the present invention also provides, in a second aspect, a method of producing an electronic device, comprising: having a plurality of electrical terminals to face electrical components; Wherein the terminals include solder bumps, and that the substrate carrying one component has a plurality of electrical terminals corresponding to the terminals of the electrical component, wherein one of said electrical component and said substrate and / or Or a thermoset polymer applied to a metal surface in both and bringing the electrical component and the substrate into contact at an elevated temperature, thereby soldering the electrical component to the substrate, while at the same time in-situ resulting from said monomer or polymer With the thermosetting adhesive composition according to the first aspect of the invention to achieve its encapsulation, between a flux composition and / or a metal oxide and a crosslinking agent. Catalysis of the thermosetting adhesive achieved by the metal oxide removed from the metal surface by the salt formed by the reaction of

As far as solder is involved, it may be composed of one or more metals that provide a suitable low melting material. The metals used are generally tin, lead,
Selected from bismuth, cadmium, zinc, gallium, indium, tellurium, mercury, thallium, antimony and selenium. Such a preferred metal is tin or a tin / lead alloy. A specific example of the solder that may be used is the above-mentioned fusible Sn / Pb.
60/40 and high melting point Sn / Pb 3/97.

[0013] The thermosetting polymer or monomer of the composition utilized in the components of the present invention is preferably an adhesive material that is liquid at room temperature. Thus, epoxide monomers or polymers such as reactive polyesters or epoxy novolaks or epoxide precursors thereof can be utilized. Preferred epoxy resins are either diglycidyl ether of bisphenol A or diglycidyl ether of bisphenol F. In a preferred implementation, such an epoxy resin is a B-stage resin, or a resin that may be "B-stage" after application, so that it can be retarded there before the element and substrate are brought together. Become. Other preferred epoxy materials for use are Ciba-Geigy resin araldites (A) such as the trifunctional epoxide MY10510 and the bifunctional cycloaliphatic epoxide ERL4221.
raldite) series, which may be used alone or as a mixture. Araldite MY10510 may be replaced by Araldite MY9512, which is a tetrafunctional epoxide. Trifunctional epoxide MY
Like 10510, MY9512 may also be used alone. The composition of the present invention may contain a monomer precursor of the epoxide compound if a polymer, for example an epoxy resin, is required. Mixtures of such epoxy materials also
May be used.

The crosslinking agent having flux properties is usually solid at room temperature, but may be liquid at room temperature as long as the above-mentioned requirement for the reactivity of the adhesive composition embodying the present invention with the crosslinking agent is satisfied. Good. The cross-linking agent is not reactive at room temperature, and in fact, is generally preferably a di- or poly-carboxyl compound that is insoluble in monomers or polymers until heated to the soldering temperature. Here, it is called polyacid. For this reason, the crosslinker is preferably solid. Such a polyacid acts as a flux agent for oxides present on the solder,
Oxides are catalysts for the high temperature reaction between the epoxy resin and the carboxyl groups of the polymer.
Such polyacids are, in particular, carboxylated polymers, polyfunctional polyanhydrides or long-chain (C ₈ or more, preferably C ₁₀ or more) polycarboxylic acids, preferably dicarboxylic acids. These acidic reactive compounds with more than one functional group are:
Provides multiple reaction sites with epoxy resin acting on creation of adhesive polymer. Particularly preferred examples of the used polymer containing two or more carboxyl groups are:
It is a styrene-acrylic acid copolymer. A preferred dicarboxylic acid is dodecane diacid (DDDA).

[0015] Polyanhydrides, which are used as fluxing cross-linking agents in the practice of the present invention and are preferably solid, include polyazelate polyanhydride and polyadipate polyanhydride. These materials provide stability when mixed with the epoxy resin and become active fluxing and curing agents only when heated to the melting point.

Other crosslinkers which can be used with flux properties are monohydrazides, dihydrazides and polyhydrazides, each of which is solid at room temperature and in fact is insoluble in monomers and polymers until heated to the soldering temperature. is there. A preferred such compound is adipic hydrazide. Because of the different reactivity of polycarboxylic acid and hydrazide, it is preferable to use a cross-linking agent mixture such as dodecane diacid and adipic hydrazide, but in the mixture, the higher reactivity of the latter is lower than that of the former. Offset by reactivity.

The oxide removed from the solder, or the salt formed by the reaction of the polyacid with the oxide, acts as a catalyst for polymer curing as a result of the fluxing activity of the crosslinker, but in a fast curing and fixing manner. Is achieved only when the catalyst is present and active at the high temperatures used for soldering. A preferred such potential catalyst is an imidazole catalyst, especially phenylimidazole. This effect is often undesirable because it conflicts with the need to adjust the positioning of the component during soldering. Other potential reaction catalysts that can be used are the aforementioned Araldite MY10510 or MY10510
Amine-containing tertiary amines such as 9512, which may be used in place of reactive monomers or polymers, or tin octoate, dibutyl tin dilaurate, ferric acetylacetonate, cobalt acetylacetonate (III), etc. Is a metal salt.

Preferred compositions embodying the present invention comprise from 45 to 70% by weight of the thermosetting polymer, more preferably from 50 to 60% by weight, and from 55 to 30% by weight of the crosslinking agent / flux, more preferably from 50 to 30% by weight. It should have a thermosetting polymer-crosslinker / flux content that is 40% by weight.

These curing agents are combined to produce a series of products with an underfill stiffness.

The use of a ceramic powder in a flip chip bonding encapsulating adhesive composition to increase the thermal expansion and elasticity of the composition is as described herein above and in the practice of the present invention. Is preferably adopted. In order to increase the connectivity between the solder bumps on the substrate and the conductor, while ensuring that the composition retains the low viscosity required for flux formation and easy adhesion, such ceramic powders have a high thermal conductivity It is preferable to have Preferably, the filler is a spherical ceramic bead having a nominal diameter of 5μ or a hollow sphere composition. More generally, the filler is a glass or ceramic powder containing spherical particles of diameter 0.1-25μ, preferably 1-15μ, or a single diameter 0.1-25μ, preferably 1-25μ. It may comprise essentially monodisperse spherical particles having 〜15μ. Preferably, the ceramic powder has a very high thermal conductivity. Examples of such ceramic powder used _is, SiO _{2, MgO,}
Al ₂ O ₃ , TiO ₂ / ZnO, barium sulfate and diamond powder. In some cases, it is also preferred that the ceramic powder utilized instead has a very low or negative coefficient of thermal expansion; if this requirement is imposed on the ceramic powder, a preferred example is lithium aluminum silicate .

[0021] The metal oxides formed on the solder metal at room temperature are themselves problematic because they can catalyze the crosslinking of the thermosetting resin or its monomer precursor. According to a preferred embodiment of the present invention, the resin or precursor contains an acid flux that is liquid at a temperature below 100 ° C., preferably below 40 ° C., more preferably at room temperature. This acid reacts with oxides to form salts that do not decompose at high temperatures, especially at soldering temperatures, but the oxides formed by high-temperature decomposition are more easily formed on metal surfaces at higher temperatures, It has the property of catalyzing the crosslinking of the thermosetting polymer, together with the oxide removed from the metal surface by the flux / crosslinking agent.

The term “acid” per se refers to a more volatile flux to prevent prepolymerization / crosslinking and is used to distinguish it from solid crosslinkers / flux. The more volatile flux is generally liquid at room temperature and thus acts immediately as a flux. It is certain that the flux should be liquid at least below the temperature at which the crosslinking agent used is completely reactive in the presence of the metal oxide / salt crosslinking catalyst. Therefore, it is preferable that the acid used to prevent the prepolymerization becomes liquid before reaching 40 ° C. even if it is solid at room temperature.

Such a liquid acid may be a polyacid, but is usually a monocarboxylic acid.
. Said acid preferably contains at least 8 carbon atoms,
C acids, especially Versatic 10, which is a C _Ten Synthesis of mainly tertiary structures composed of a mixture of highly branched isomers of monocarboxylic acids
Is an acid. The high degree of branching causes steric hindrance, so that the salt formed is extremely
Stable and difficult to decompose. Other acids that may be used are capric acid, caprylic acid, lauric acid
Acids, stearic acid and palmitic acid.

When such a monocarboxylic acid is to be used, the thermosetting polymer-flux content of the composition embodying the present invention is from 30 to 70%.
%, More preferably 50 to 60% by weight, the flux mixture is 70 to 3%.
0% by weight, more preferably 50 to 40% by weight, wherein said flux component is a solid crosslinker / flux of 80 to 97% by weight, preferably 85 to 95% by weight / 1.
The acid flux liquid below 00 ° C. comprises 20 to 3% by weight, preferably 15 to 5% by weight.

When utilizing the composition of the present invention, it is not necessary to introduce the composition after the formation of the solder with the difficulties already identified. Before installing the electronic components on the board and soldering,
It is possible to pre-place the composition on one or both of the electronic component and the substrate. Since a flux forming agent that is separately used without being taken into the adhesive composition is unnecessary, a required flux forming function is realized if the composition is present in either the electronic component or the substrate. The only application of the composition to electronic components is to apply to the entire die, whether in wafer form or individual devices. Application of the composition may be by screen printing, stencil printing, dispenser application, spinner application or any other known method of applying the composition to individual areas.

Due to the ease of operation according to the method of the present invention, the composition can contain a thermosetting resin in the form of a B-stageable precursor for application to a die, substrate or carrier tape, and then handle B-staging can be performed to form a possible film, but the film crosslinks completely only when a soldering operation is performed.

The following examples illustrate the adhesive compositions used in the practice of the present invention. In all examples, all percentages are weight percentages.

Example 1 ERL 4221 40.6% MY 9512 12.7% DDDA 46.7% This composition was functionally good for most applications and had sufficient viscosity.

Example 2 ERL 4221 39.65% Epoxy MY9512 12.40% DDDA 41.05% Versatic 10 6.90% This composition is functionally good in that it does not undergo pre-crosslinking, but for some applications Had too low a viscosity. As a result, a more viscous composition, such as:
It turned out to work well.

Example 3 ERL 4221 33.45% MY 9512 18.60% DDDA 41.05% Versatic 10 6.90% Example 4 ERL 4221 26.05% MY 9512 26.00% DDDA 41.05% Versatic 10 6.90% Example 5 ERL 4221 12.40% MY 9512 39.65% DDDA 41.05% Versatic 10 6.90% In the above three examples, the initial viscosity of the composition is too high to use. Moreover,
In Examples 2 to 5, a monocarboxylic acid which is liquid at normal temperature was used. However, it is also possible to use a monocarboxylic acid which is solid at normal temperature but which is liquid at a temperature lower than its melting point, for example, the crosslinker / flux is as follows. It is.

Example 6 ERL 4221 39.65% Epoxy MY9512 12.40% DDDA 41.05% Prifrac 2960 6.90% (C16 palmitic acid, solid melts at 60 ° C.) Example 7 ERL 4221 39.65 % Epoxy MY9512 12.40% DDDA 41.05% Versatic 10 6.90% (C18, melting at 69 ° C.) Finally, a composition containing a reduced amount of monocarboxylic acid was formulated. These have also proved satisfactory.

Example 8 ERL 4221 39.65% MY 9512 12.40% DDDA 44.95% Versatic 10 3.00% Example 9 ERL 4221 42.62% MY 9512 13.33% DDDA 41.05% Versatic 10 3.00%

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) H01L 23/31 (81) Designated countries AE, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE , KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, US, UZ, VN, YU, ZA, ZW (71) Applicant Craig, Hugh, Patrick CRAIG, Hugh, Patrick England, UK 151 P.E.S. 72) Inventors Lowry, David, John, James James, UK 42 PB Lincoln Bracebridge Heath the Crows 4 F-term (Reference) 4J036 AA01 AA04 AD08 AJ01 AJ02 AJ03 AJ08 DA01 DB17 DB18 DC05 DC35 DC41 FA01 FA02 FA03 FA04 FA04 GA09 GA17 JA07 4M109 AA01 BA04 EA11 EA20 EC20 5F044 LL01 LL11 RR17 RR18 5F061 AA01 BA04 CB02

Claims (42)

[Claims] 1. A thermosetting polymer, or a monomer that can be polymerized to produce a thermosetting polymer, which is crosslinkable when subjected to the action of a chemical crosslinker. (B) a chemical cross-linking agent for the polymer, which has a flux property and does not show reactivity with the polymer, or is extremely limited to the polymer without the action of a catalyst and / or heating. A cross-linking agent exhibiting enhanced reactivity, and the composition can be thermally cured upon heating to a soldering temperature in the presence of a catalyst for cross-linking the polymer with the cross-linking agent, and A thermosetting adhesive composition having storage stability and reaction stability at room temperature in the absence thereof. 2. The composition according to claim 1, wherein the chemical crosslinking agent is solid at normal temperature. 3. The chemical cross-linking agent is a solid at room temperature and is selected from polyacids, polyanhydrides and hydrazides which are insoluble in monomers or polymers until heated to the soldering temperature. 3. The composition according to 1 or 2. 4. The composition according to claim 3, wherein the polyacid is selected from polymers containing two or more carboxyl groups and di- and polycarboxylic acids and di- and polyanhydrides. 5. The composition according to claim 4, wherein the polycarboxylic acid is C ₈ or a larger dicarboxylic acid. 6. The composition according to claim 3, wherein the hydrazide is a monohydrazide, a dihydrazide, or a polyfunctional hydrazide. 7. The composition according to claim 3, wherein the crosslinking agent contains dihydrazide and / or dicarboxylic acid. 8. The composition according to claim 7, wherein the crosslinking agent comprises adipic dihydrazide and / or dodecadionic acid. 9. The composition according to claim 4, wherein the crosslinking agent is a styrene acrylic acid copolymer. 10. The composition according to claim 1, which comprises 30 to 70 parts by weight of a thermosetting resin. 11. The composition according to claim 1, wherein the polymer is an epoxy resin. 12. The polymer of claim 11, wherein the polymer is a B-stage epoxy resin.
A composition according to claim 1. 13. The composition according to claim 12, wherein said polymer is a diglycidyl ether of bisphenol A. 14. The composition according to claim 10, wherein the resin is a tri- or tetra-functional epoxide or a bifunctional cycloaliphatic epoxide or a mixture of two or more such epoxides. 15. 30 to 70% by weight of thermosetting polymer and 70 to 3% by weight.
A composition according to any of the preceding claims, having a thermosetting polymer-solid crosslinker / flux content of 0% by weight solid crosslinker / flux. 16. The total content of the thermosetting polymer and the solid crosslinking agent / flux is 50 to 60% by weight, and the content of the solid crosslinking agent / flux is 50 to 60% by weight. The composition according to claim 15, which is 40% by weight. 17. The composition according to claim 1, further comprising an acid flux which is liquid at a temperature of 100 ° C. or lower. 18. The composition according to claim 17, wherein the acid flux is liquid at room temperature. 19. The composition according to claim 17, wherein the acid flux is a monocarboxylic acid, preferably containing at least 8 carbon atoms. 20. The composition according to claim 19, wherein the acid flux is versatic acid, capric acid, caprylic acid, lauric acid, stearic acid, or palmitic acid. 21. 30 to 70% by weight of thermosetting polymer and 70 to 3
21. The method of claim 17, wherein the flux is 0% by weight and the flux has a content of from 80 to 97% by weight of the solid crosslinker / 20 to 3% by weight of the thermosetting polymer flux made of the acid flux. A composition according to any one of the preceding claims. 22. 50 to 60% by weight of a thermosetting polymer and 50 to 4% by weight.
22. The method of claim 21, wherein the flux is 0% by weight and the flux has a content of 85-95% by weight of the solid crosslinker / 15-5% by weight of the thermosetting polymer flux made with the acid flux. Composition. 23. The composition according to claim 1, further comprising a tertiary amine and a latent reaction catalyst selected from imidazole and metal salts. 24. The method according to claim 23, wherein the imidazole is phenylimidazole.
A composition according to claim 1. 25. The composition according to claim 23, wherein the tertiary amine is constituted by a self-catalyzed tertiary amine group substituted by a reactive monomer or polymer. 26. The composition according to claim 25, wherein the reactive monomer is a tertiary amine-substituted trifunctional or tetrafunctional epoxide. 27. The metal salt is tin octoate, dibutyltin dilaurate,
3. Ferric acetylacetone, cobalt (III) acetylacetone.
3. The composition according to 3. 28. The composition according to any of the preceding claims, further comprising a thermally conductive filler. 29. The composition of claim 28, wherein the filler reduces the thermal expansion of the composition without substantially affecting its viscosity. 30. The composition according to claim 28, wherein the filler is constituted by nominally 5μ spherical ceramic beads or hollow spheres. 31. The composition according to claim 28, wherein the filler is a ceramic or glass-ceramic powder containing a spherical particle size in the range from 0.1 to 25 μ, preferably 1 to 15 μ. 32. The method according to claim 28, wherein the filler is a ceramic or glass-ceramic powder consisting essentially of monodisperse spherical particles having a single diameter ranging from 0.1 to 25μ, preferably 1 to 15μ. A composition as described. 33. The composition according to claim 28, wherein the filler is a thermally conductive ceramic powder. 34. The composition according to claim 33, wherein the ceramic powder is selected from SiO ₂ , MgO, Al ₂ O ₃ , TiO ₂ / ZnO, barium sulfate and diamond powder. 35. The composition of claim 28, wherein the ceramic powder has a low or negative coefficient of thermal expansion. 36. The composition according to claim 35, wherein the ceramic material is lithium aluminum silicate. 37. A method comprising: having a plurality of electrical terminals to oppose electrical components; each terminal comprising a solder bump; and a substrate carrying one component,
37. Any one of claims 1 to 36 having a plurality of electrical terminals corresponding to terminals of an electrical component, applied to a metal surface on one and / or both of the electrical component and the substrate. A thermosetting adhesive composition according to claim 1, wherein the electrical component and the substrate are brought into contact at an elevated temperature, thereby soldering the electrical component to the substrate while simultaneously forming the monomer or polymer in situ. With a thermosetting adhesive composition according to the first aspect of the invention, which achieves its encapsulation in a thermoset polymer, formed by a reaction between a flux composition and / or a metal oxide and a crosslinking agent. A method of producing an electronic device, comprising the crosslinking catalysis of a thermosetting adhesive achieved by a metal oxide removed from a metal surface by a salt. 38. The method of claim 37, wherein the thermosetting adhesive composition is applied before one or both of the electrical component and the substrate are brought together. 39. The method of claim 37 or claim 38, wherein no fluxing agent is applied to either the electrical component or the substrate prior to applying the solder-curable adhesive composition.
The method described in. 40. The method according to any one of claims 37 to 39, wherein the thermosetting adhesive composition is applied to a die, either in wafer form or as a discrete device. 41. The thermosetting adhesive composition is applied by screen printing, stencil printing, dispensing, or spinning.
41. The method according to any one of claims 1 to 40. 42. The method according to any one of claims 37 to 41, wherein the thermosetting adhesive composition is applied in an in-situ B-stage form and in the B-stage.