JP2012160610A - Method for manufacturing connected structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a connected structure which implements improved reliability of continuity between electrodes.SOLUTION: The method for manufacturing a connected structure 1 includes the steps of: disposing an anisotropic conductive material layer using an anisotropic conductive material containing conductive particles 5 on a first connection member 2 having electrodes 2b on an upper surface 2a; overlaying a second connection member 4 having electrodes 4b on a lower surface 4a on an upper surface of the anisotropic conductive material layer; lowering a thermo-compression bonding head onto an upper surface 4c of the second connection member 4, and setting the anisotropic conductive material layer with the thermo-compression bonding head in contact with the upper surface 4c of the second connection member 4; and lifting the thermo-compression bonding head from the upper surface 4c of the second connection member 4. In the method of manufacturing the connected structure 1, the conductive particles 5 are pressed to form recessed portions in the electrodes before the anisotropic conductive material layer reaches a setting start temperature.

Description

  The present invention relates to a method for manufacturing a connection structure using an anisotropic conductive material containing conductive particles, and more specifically, for example, electrodes of various connection target members such as a flexible printed board, a glass substrate, and a semiconductor chip. The present invention relates to a method for manufacturing a connection structure in which a space is electrically connected via conductive particles.

  Pasty or film-like anisotropic conductive materials are widely known. In the anisotropic conductive material, a plurality of conductive particles are dispersed in a binder resin or the like.

  The anisotropic conductive material includes, for example, a connection between a flexible printed circuit board and a glass substrate (FOG (Film on Glass)), a connection between a semiconductor chip and a flexible printed circuit board (COF (Chip on Film)), and a semiconductor chip. It is used for connection with a glass substrate (COG (Chip on Glass)) and the like.

  For example, when the semiconductor chip electrode and the glass substrate electrode are electrically connected by the anisotropic conductive material, the anisotropic conductive material is disposed between the semiconductor chip electrode and the glass substrate electrode. Then, heat and pressurize. As a result, the anisotropic conductive material is cured, and the electrodes are electrically connected via the conductive particles to obtain a connection structure.

  Moreover, as an example of the manufacturing method of the said connection structure, the following patent document 1 has the 1st and 2nd through the anisotropic conductive film in which the electroconductive particle was disperse | distributed by using the insulating adhesive as a base material. A method for manufacturing a connection structure in which members to be connected are bonded to each other is disclosed. Here, when the first and second members to be bonded are bonded by thermocompression bonding, the surface roughness value (Ra) of the indentation formed on the surface of the first member to be connected is 0.1 μm or more. 0 μm or less.

WO2007 / 083963A1

  As described in Patent Document 1, even if an indentation having a surface roughness value (Ra) of 0.1 μm or more and 5.0 μm or less is formed on a member to be connected, in the obtained connection structure, the connection between the electrodes The resistance may increase or the electrodes may not be reliably connected. That is, in the obtained connection structure, conduction reliability may be low.

  The objective of this invention is providing the manufacturing method of the connection structure which can improve the conduction | electrical_connection reliability between electrodes.

  According to a wide aspect of the present invention, anisotropic conduction using an anisotropic conductive material including a thermosetting compound, a thermosetting agent, and conductive particles on a first connection target member having an electrode on an upper surface thereof. A step of disposing a material layer; a step of laminating a second connection target member having an electrode on the lower surface thereof on the upper surface of the anisotropic conductive material layer; and a thermocompression bonding head on the upper surface of the second connection target member. And the step of curing the anisotropic conductive material layer in a state where the thermocompression bonding head is in contact with the upper surface of the second connection target member, and from the upper surface of the second connection target member, A step of lifting the thermocompression bonding head, and in the step of curing the anisotropic conductive material layer, the conductivity in the anisotropic conductive material layer until the anisotropic conductive material layer reaches a curing start temperature. Components other than particles are removed from between the electrode and the conductive particles. Dividing it, the conductive particles form a recess pressed into the electrode, method for producing a connection structure is provided.

  On the specific situation with the manufacturing method of the connection structure which concerns on this invention, the hardening start temperature of the said anisotropic conductive material layer is 50 degreeC or more and 100 degrees C or less.

  In another specific aspect of the method for manufacturing a connection structure according to the present invention, in the anisotropic conductive material layer or a cured product layer thereof immediately after the thermocompression bonding head is pulled up from the upper surface of the second connection target member. The reaction rate of the thermosetting compound is 80% or more.

  In another specific aspect of the manufacturing method of the connection structure according to the present invention, the thermocompression bonding head is lowered as the anisotropic conductive material, and the lower surface of the thermocompression bonding head is the second connection target member. An anisotropic conductive material that flows immediately after contacting the upper surface is used.

  In still another specific aspect of the method for manufacturing a connection structure according to the present invention, after the thermocompression bonding head is in contact with the upper surface of the second connection target member, the thermocompression bonding head is connected to the second connection target member. The time until it is lifted from the upper surface is 8 seconds or less.

  In the method for manufacturing a connection structure according to the present invention, the second connection target member is laminated on the upper surface of the anisotropic conductive material layer laminated on the first connection target member, and then the second connection target member. The upper surface of the thermocompression bonding head is lowered, and the anisotropic conductive material layer is cured in a state where the thermocompression bonding head is in contact with the upper surface of the second connection target member, and then the second connection target. Since the thermocompression bonding head is lifted from the upper surface of the member, the components excluding the conductive particles in the anisotropic conductive material layer are further removed from the electrode and the conductive material until the anisotropic conductive material layer reaches the curing start temperature. Since the concave portion in which the conductive particles are pushed into the electrode is formed by eliminating the conductive particles, the electrode and the conductive particles can be contacted with higher accuracy. Therefore, it is possible to provide a connection structure having excellent conduction reliability between the electrodes.

FIG. 1 is a front sectional view schematically showing a connection structure obtained by a method for manufacturing a connection structure according to an embodiment of the present invention. 2 (a) to 2 (b) are front cross-sectional views for explaining each step of the manufacturing method of the connection structure according to one embodiment of the present invention. 3 (a) to 3 (b) are front cross-sectional views for explaining each step of the method for manufacturing a connection structure according to one embodiment of the present invention. FIG. 4 is a schematic view for explaining a recess formed in the electrode.

  Hereinafter, the present invention will be clarified by describing specific embodiments of the present invention with reference to the drawings.

  In FIG. 1, an example of the connection structure obtained by the manufacturing method of the connection structure which concerns on one Embodiment of this invention is typically shown with a partial notch front sectional drawing.

  A connection structure 1 shown in FIG. 1 includes a first connection target member 2, a second connection target member 4, and a connection part 3 connecting the first and second connection target members 2 and 4. Prepare. The connection portion 3 is a cured product layer and is formed by curing an anisotropic conductive material including the conductive particles 5.

  A plurality of electrodes 2 b are provided on the upper surface 2 a of the first connection target member 2. A plurality of electrodes 4 b are provided on the lower surface 4 a of the second connection target member 4. The electrode 2b and the electrode 4b are electrically connected by one or a plurality of conductive particles 5.

  In the connection structure 1, a glass substrate is used as the first connection target member 2, and a semiconductor chip is used as the second connection target member 4. The first and second connection target members are not particularly limited. Specific examples of the first and second connection target members include electronic components such as semiconductor chips, capacitors, and diodes, and circuit boards such as printed boards, flexible printed boards, and glass boards.

  In the manufacturing method of the connection structure according to the present embodiment, the connection structure 1 shown in FIG. 1 is obtained as follows.

  As shown to Fig.2 (a), the 1st connection object member 2 which has the electrode 2b on the upper surface 2a is prepared. An anisotropic conductive material including a thermosetting compound, a thermosetting agent, and conductive particles 5 is prepared.

  Next, an anisotropic conductive material containing conductive particles 5 is laminated on the upper surface 2a of the first connection target member 2, and the anisotropic conductive material layer 3A is formed on the upper surface 2a of the first connection target member 2. Form and place. At this time, it is preferable that one or a plurality of conductive particles 5 be disposed on the electrode 2b. When the anisotropic conductive material is an anisotropic conductive paste, the lamination of the anisotropic conductive paste is performed by applying the anisotropic conductive paste.

  Next, as shown in FIG. 2B, the second connection target member 4 having the electrode 4b on the lower surface 4a is laminated on the upper surface 3a of the anisotropic conductive material layer 3A. The second connection target member 4 is laminated so that the electrode 2b on the upper surface 2a of the first connection target member 2 and the electrode 4b on the lower surface 4a of the second connection target member 4 face each other.

  Note that before the second connection target member 4 is laminated, the anisotropic conductive material layer 3A may be B-staged by irradiating the anisotropic conductive material layer 3A with light or applying heat. Good. The anisotropic conductive material layer 3A may be a B-staged anisotropic conductive material layer.

  Next, as shown in FIG. 3A, the thermocompression bonding head 11 is lowered onto the upper surface 4 c of the second connection target member 4. After lowering the thermocompression bonding head 11, the anisotropic conductive material layer 3 </ b> A is cured in a state where the lower surface 11 a of the thermocompression bonding head 11 is in contact with the upper surface 4 c of the second connection target member 4. A certain connection part 3 is formed.

  After the anisotropic conductive material layer 3A is cured, the thermocompression bonding head 11 is pulled up from the upper surface 4c of the second connection target member 4 to obtain the connection structure 1 as shown in FIG.

  Further, after the thermocompression bonding head 11 is lifted from the upper surface 4c of the second connection target member 4, the connection portion 3 may be further heated and cured.

  In the present embodiment, the components excluding the conductive particles 5 in the anisotropic conductive material layer 3A are excluded from between the electrode 2b and the conductive particles 5 until the anisotropic conductive material layer 3A reaches the curing start temperature. Thus, a recess in which the conductive particles 5 are pushed into the electrode 2b is formed. As shown in FIG. 4, when the conductive particles 5 are pushed in, the recess 2c is formed in the electrode 2b, and the recess can be formed in the electrode 4b. Thus, the resin component which exists between the electroconductive particle 5 and the electrode 2b is effectively excluded because the anisotropic conductive material layer 3A does not reach the curing start temperature in the step of forming the recess 2c. can do. It is preferable to pressurize the upper surface 2c of the second connection target member 2 until at least the recess 2c is formed, and it is preferable to lower the thermocompression bonding head 11. In addition, the said recessed part 2c is also called an indentation. The resin component is a component excluding the conductive particles 5 in the anisotropic conductive material. Examples of the component excluding the conductive particles include a thermosetting compound and a thermosetting agent. By eliminating the resin component, the conductive particles 5 and the electrode 2b can be effectively brought into contact with each other. Therefore, the conduction reliability between the electrodes 2b and 4b in the obtained connection structure 1 can be improved.

  By removing the components excluding the conductive particles 5 in the anisotropic conductive material layer 3A from between the electrode 4b and the conductive particles 5 until the anisotropic conductive material layer 3A reaches the curing start temperature, the electrode 4b You may form the recessed part into which the electroconductive particle 5 was pushed in. That is, in the present invention, (1) components other than the conductive particles in the anisotropic conductive material layer are excluded from between the electrodes provided on the upper surface of the first connection target member and the conductive particles. The concave portion in which the conductive particles are pushed into the electrode provided on the upper surface of the first connection target member may be formed. (2) The component excluding the conductive particles in the anisotropic conductive material layer Forming a recess in which the conductive particles are pushed into the electrode provided on the upper surface of the second connection target member, excluding from between the electrode provided on the lower surface of the connection target member of 2 and the conductive particles (3) The first connection by excluding the component excluding the conductive particles in the anisotropic conductive material layer from between the electrode provided on the upper surface of the first connection target member and the conductive particles. Forming a recess in which conductive particles are pressed into an electrode provided on the upper surface of the target member, and an anisotropic conductive material The components excluding the conductive particles therein are excluded from between the electrode provided on the lower surface of the second connection target member and the conductive particles, and are electrically connected to the electrode provided on the upper surface of the second connection target member. You may form the recessed part into which the property particle was pushed.

  In the present specification, the curing start temperature means a temperature at which an exothermic peak begins to be observed when the reaction heat is measured using a DSC (differential scanning calorimeter).

  The reaction rate R of the thermosetting compound in the anisotropic conductive material layer or its cured product layer immediately after the thermocompression bonding head 11 is pulled up from the upper surface 4c of the second connection target member 4 is preferably 40% or more. Preferably it is 60% or more, particularly preferably 80% or more, most preferably 90% or more and 100% or less. The higher the reaction rate R, the more indentations can be formed. In particular, when the reaction rate R is 80% or more, the formation of indentations is considerably improved.

  In the present specification, the reaction rate R means a value calculated from the following formula by measuring the reaction heat amount of a reactive functional group using a DSC (differential scanning calorimeter).

  Reaction rate R (%) = (1- (reaction heat amount of cured product after reaction / reaction heat amount of unreacted cured product)) × 100

  As the anisotropic conductive material, an anisotropic conductive material that flows immediately after the lower surface 11a of the thermocompression bonding head 11 comes into contact with the upper surface 4a of the second connection target member 4 is used by lowering the thermocompression bonding head 11. Is preferred. In this case, the resin between the conductive particles and the electrode is sufficiently eliminated, and a sufficient impression can be formed. When the thermocompression bonding head 11 is lowered when the anisotropic conductive material is in the B stage state, immediately after the lower surface 11a of the thermocompression bonding head 11 contacts the upper surface 4c of the second connection target member 4. It is preferable that the anisotropic conductive material in the B stage state melts and flows. Examples of a method for forming an anisotropic conductive material that passes through such a molten state include a method using a resin having a Tg of room temperature or higher and lower than the pressure bonding temperature for the anisotropic conductive material.

  The time H (crimp holding time) from when the thermocompression bonding head 11 comes into contact with the upper surface 4c of the second connection target member 4 to when the thermocompression bonding head 11 is pulled up from the upper surface 4a of the second connection target member 4 is preferably It is 5 seconds or more, more preferably 6 seconds or more, preferably 10 seconds or less, more preferably 8 seconds or less. When the time H is not less than the above lower limit and not more than the above upper limit, the formation of the indentation is further improved. In particular, when the time H is 8 seconds or less, the formation of indentations is considerably improved.

  The anisotropic conductive material is a paste-like or film-like anisotropic conductive material, and is preferably a paste-like anisotropic conductive material. The paste-like anisotropic conductive material is an anisotropic conductive paste. The film-like anisotropic conductive material is an anisotropic conductive film. When the anisotropic conductive material is an anisotropic conductive film, a film that does not include conductive particles may be laminated on the anisotropic conductive film that includes the conductive particles.

  The viscosity of the anisotropic conductive paste at 25 ° C. is preferably 20 Pa · s or more, and preferably 300 Pa · s or less. When the viscosity is equal to or higher than the lower limit, sedimentation of conductive particles in the anisotropic conductive paste can be suppressed. When the viscosity is equal to or lower than the upper limit, the dispersibility of the conductive particles is further increased. If the viscosity of the anisotropic conductive paste before coating is within the above range, after applying the anisotropic conductive paste on the first connection target member, the flow of the anisotropic conductive paste before curing is further increased. It can be further suppressed.

  Hereinafter, the detail of each component contained in the said anisotropic conductive material is demonstrated.

(Thermosetting compound)
Examples of the thermosetting compound include epoxy compounds, episulfide compounds, (meth) acrylic compounds, phenolic compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, silicone compounds, and polyimide compounds. As for the said thermosetting compound, only 1 type may be used and 2 or more types may be used together.

  From the viewpoint of easily controlling the curing of the anisotropic conductive material or further improving the conduction reliability of the connection structure, the thermosetting compound is a thermosetting compound having an epoxy group or a thiirane group. It is preferable that The compound having an epoxy group is an epoxy compound. The compound having a thiirane group is an episulfide compound. From the viewpoint of allowing thermosetting to proceed more rapidly, the thermosetting compound is preferably an episulfide compound.

  Since the episulfide compound has a thiirane group instead of an epoxy group, it can be cured quickly at a low temperature. That is, the episulfide compound having a thiirane group can be cured at a lower temperature derived from the thiirane group as compared with the epoxy compound having an epoxy group.

(Thermosetting agent)
The said thermosetting agent is not specifically limited. A conventionally known thermosetting agent can be used as the thermosetting agent. Examples of the thermosetting agent include imidazole curing agents, amine curing agents, phenol curing agents, polythiol curing agents, and acid anhydrides. As for the said thermosetting agent, only 1 type may be used and 2 or more types may be used together.

  Since the anisotropic conductive material can be cured more rapidly at a low temperature, the thermosetting agent is preferably an imidazole curing agent, a polythiol curing agent, or an amine curing agent. In addition, a latent curing agent is preferable because the storage stability of the anisotropic conductive material can be improved. The latent curing agent is preferably a latent imidazole curing agent, a latent polythiol curing agent or a latent amine curing agent. The thermosetting agent may be coated with a polymer material such as polyurethane resin or polyester resin.

  The content of the thermosetting agent is not particularly limited. The content of the thermosetting agent is preferably 5 parts by weight or more, more preferably 10 parts by weight or more, preferably 30 parts by weight or less, more preferably 20 parts by weight or less with respect to 100 parts by weight of the thermosetting compound. It is. When the content of the thermosetting agent is not less than the above lower limit and not more than the above upper limit, the anisotropic conductive material can be sufficiently thermoset.

(Conductive particles)
The conductive particles contained in the anisotropic conductive material electrically connect the electrodes of the first and second connection target members. The conductive particles are not particularly limited as long as they are conductive particles. The surface of the conductive layer of the conductive particles may be covered with an insulating layer. In this case, the insulating layer between the conductive layer and the electrode is excluded when the connection target member is connected. Examples of the conductive particles include conductive particles whose surfaces are covered with a metal layer, such as organic particles, inorganic particles, organic-inorganic hybrid particles, or metal particles, or metal particles that are substantially composed only of metal. It is done. The metal layer is not particularly limited. Examples of the metal layer include a gold layer, a silver layer, a copper layer, a nickel layer, a palladium layer, or a metal layer containing tin.

  From the viewpoint of further enhancing the conduction reliability between the electrodes, the conductive particles preferably include resin particles and a conductive layer provided on the surface of the resin particles.

  The average particle diameter of the conductive particles is preferably 0.5 μm or more, more preferably 1 μm or more, preferably 100 μm or less, more preferably 20 μm or less, and even more preferably 15 μm or less.

  The “average particle diameter” of the conductive particles indicates the number average particle diameter. The average particle diameter of the conductive particles can be obtained by observing 50 arbitrary conductive particles with an electron microscope or an optical microscope and calculating an average value.

  The content of the conductive particles is not particularly limited. In 100% by weight of the anisotropic conductive material, the content of the conductive particles is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, preferably 20% by weight or less, more preferably 15% by weight. % Or less. A conductive particle can be easily arrange | positioned between the upper and lower electrodes which should be connected as content of the said electroconductive particle is more than the said minimum and below the said upper limit. Furthermore, it becomes difficult to electrically connect adjacent electrodes that should not be connected via a plurality of conductive particles. That is, a short circuit between adjacent electrodes can be further prevented.

(Other ingredients)
The anisotropic conductive material preferably contains a filler. By using the filler, latent heat expansion of the cured product of the anisotropic conductive material can be suppressed. Specific examples of the filler include silica, aluminum nitride, and alumina. As for a filler, only 1 type may be used and 2 or more types may be used together.

  The anisotropic conductive material preferably further contains a curing accelerator. By using a curing accelerator, the curing rate can be further increased. As for a hardening accelerator, only 1 type may be used and 2 or more types may be used together.

  Specific examples of the curing accelerator include imidazole curing accelerators and amine curing accelerators. Of these, imidazole curing accelerators are preferred. In addition, an imidazole hardening accelerator or an amine hardening accelerator can be used also as an imidazole hardening agent or an amine hardening agent.

  The anisotropic conductive material may contain a solvent. By using the solvent, the viscosity of the anisotropic conductive material can be easily adjusted. Examples of the solvent include ethyl acetate, methyl cellosolve, toluene, acetone, methyl ethyl ketone, cyclohexane, n-hexane, tetrahydrofuran, and diethyl ether.

  In addition, the anisotropic conductive material may contain a photocurable compound and a photopolymerization initiator so that the anisotropic conductive material can be cured by light irradiation. In the case of a two-step reaction in which the resin is semi-cured by light irradiation and then fully cured by heat, the anisotropic conductive material can shorten the reaction time during the main curing.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The present invention is not limited only to the following examples.

Example 1
(1) Preparation of anisotropic conductive material An episulfide compound having a structure represented by the following formula (1B) was prepared.

  30 parts by weight of an episulfide compound having a structure represented by the above formula (1B), 5 parts by weight of an amine adduct (“PN-23J” manufactured by Ajinomoto Fine Techno Co.) as a thermosetting agent, and 2- 1 part by weight of ethyl-4-methylimidazole, 20 parts by weight of silica (average particle diameter of 0.25 μm) as filler and 20 parts by weight of alumina (average particle diameter of 0.5 μm) as filler are blended, and the average After adding conductive particles having a particle diameter of 3 μm so that the content in 100% by weight of the composition was 10% by weight, the composition was obtained by stirring for 5 minutes at 2000 rpm using a planetary stirrer. .

  The conductive particles used are conductive particles having a metal layer in which a nickel plating layer is formed on the surface of divinylbenzene resin particles and a gold plating layer is formed on the surface of the nickel plating layer. is there.

  The obtained blend was filtered using a nylon filter paper (pore diameter: 10 μm) to obtain an anisotropic conductive paste having a conductive particle content of 10% by weight.

(2) Production of Connection Structure A transparent glass substrate (first connection target member) having an Al-4% Ti electrode pattern with an L / S of 15 μm / 15 μm formed on the upper surface was prepared. A semiconductor chip (second connection target member) having a copper electrode pattern with an L / S of 15 μm / 15 μm and an electrode area per electrode of 1500 μm ² formed on the lower surface was prepared.

  On the transparent glass substrate, the obtained anisotropic conductive paste was applied to a thickness of 20 μm to form an anisotropic conductive paste layer. Next, the semiconductor chip was stacked on the anisotropic conductive paste layer so that the electrodes face each other and are connected. Thereafter, the thermocompression bonding head was lowered onto the upper surface of the semiconductor chip, and the anisotropic conductive paste layer was cured with the thermocompression bonding head in contact with the upper surface of the semiconductor chip. Thereafter, the thermocompression bonding head was lifted from the upper surface of the semiconductor chip. In this way, a connection structure was produced.

The time H from when the thermocompression bonding head was brought into contact with the upper surface of the semiconductor chip to when the thermocompression bonding head was pulled up from the upper surface of the semiconductor chip was 8 seconds.
Moreover, the temperature T of the anisotropic conductive paste layer immediately before pulling up the thermocompression bonding head was 180 ° C.

(Example 2)
An episulfide compound having a structure represented by the following formula (2B) was prepared.

  An anisotropic conductive paste was obtained in the same manner as in Example 1 except that the episulfide compound having the structure represented by the formula (1B) was changed to the episulfide compound represented by the formula (2B). A connection structure was produced in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Example 3)
An anisotropic conductive paste was obtained in the same manner as in Example 1 except that the episulfide compound having the structure represented by the formula (1B) was changed to an episulfide compound (“YL7007” manufactured by Mitsubishi Chemical Corporation). A connection structure was produced in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

Example 4
An anisotropic conductive paste in the same manner as in Example 1, except that the episulfide compound having the structure represented by the above formula (1B) was changed to resorcinol glycidyl ether (“EX-201” manufactured by Nagase ChemteX Corporation). Got. A connection structure was produced in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Example 5)
An anisotropic conductive paste was obtained in the same manner as in Example 1 except that the thermosetting agent was changed to an amine adduct (“MY-24” manufactured by Ajinomoto Fine Techno Co., Ltd.). A connection structure was produced in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Example 6)
An anisotropic conductive paste was obtained in the same manner as in Example 1 except that the thermosetting agent was changed to an imidazole adduct (“P-0505” manufactured by Shikoku Kasei Co., Ltd.). A connection structure was produced in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Example 7)
An anisotropic conductive paste was obtained in the same manner as in Example 1 except that the conductive particles were changed to nickel metal particles having an average particle diameter of 3 μm. A connection structure was produced in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Example 8)
A connection structure was fabricated in the same manner as in Example 1 except that the semiconductor chip (second connection target member) was changed to a flexible printed board.

(Examples 9-12 and Comparative Examples 1-2)
A connection structure was fabricated in the same manner as in Example 1 except that the temperature T and the time H were changed as shown in Table 1 below.

(Comparative Example 3)
An anisotropic conductive paste was obtained in the same manner as in Example 1 except that the thermosetting agent was changed to an imidazole adduct (“2MA-OK” manufactured by Shikoku Kasei Co., Ltd.). A connection structure was produced in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Evaluation)
(1) Curing start temperature By measuring the temperature at which an exothermic peak begins to be observed when the reaction heat is measured using a DSC (Differential Scanning Calorimeter) (“Q2000” manufactured by TA Instruments), the anisotropy is measured. The curing start temperature of the conductive paste was evaluated.

(2) Indentation state About the connection part of 100 electroconductive particles and an electrode in the obtained connection structure, the state of the indentation formed in the electrode was observed.

Using a polarizing microscope, it was judged that good indentation was formed when an average of 25 or more spherical indentations per electrode (per 1500 μm ² ) could be confirmed. Moreover, it was judged that formation of an indentation was inadequate when the average of less than five spherical indentations per electrode (per 1500 μm ² ) could be confirmed. The indentation state was determined according to the following criteria.

[Indentation state]
◯: On average, 25 or more clear spherical indentations can be confirmed in 100 connected portions. ○: On average, 5 or more clear spherical indentations can be confirmed in 100 connected portions. Average of less than 5 spherical indentations

(3) Conduction reliability (conductivity test between upper and lower electrodes)
The connection resistance between the upper and lower electrodes of the obtained connection structure was measured by a four-terminal method. The average value of the connection resistance at 100 locations was calculated. Note that the connection resistance can be obtained by measuring the voltage when a constant current is passed from the relationship of voltage = current × resistance.

(4) Reaction rate R
The reaction rate R of the thermosetting compound in the anisotropic conductive paste layer or its cured product layer immediately after the thermocompression bonding head was lifted from the upper surface of the semiconductor chip was evaluated.

(5) Flow state of anisotropic conductive material At the time of manufacturing the connection structure, the thermocompression bonding head is lowered and immediately after the lower surface of the thermocompression bonding head is in contact with the upper surface of the second connection target member, Whether the anisotropic conductive paste layer flows was evaluated by observing with a camera from the lower part of the connection structure. Whether or not the anisotropic conductive paste layer is flowing was determined by the flow of the conductive particles.
[Criteria for fluid state]
○: Flow of conductive particles is observed ×: Flow of conductive particles is not observed

  The results are shown in Table 1 below.

  In Comparative Examples 1 to 3, no indentation was observed, and the resistance value could not be measured.

DESCRIPTION OF SYMBOLS 1 ... Connection structure 2 ... 1st connection object member 2a ... Upper surface 2b ... Electrode 2c ... Recess 3 ... Connection part 3a ... Upper surface 3A ... Anisotropic conductive material layer 4 ... 2nd connection object member 4a ... Lower surface 4b ... Electrode 4c ... Upper surface 5 ... Conductive particles 11 ... Thermocompression bonding head 11a ... Lower surface

Claims (5)

Disposing an anisotropic conductive material layer using an anisotropic conductive material including a thermosetting compound, a thermosetting agent, and conductive particles on a first connection target member having an electrode on an upper surface;
Laminating a second connection object member having an electrode on the lower surface on the upper surface of the anisotropic conductive material layer;
A step of lowering the thermocompression bonding head on the upper surface of the second connection target member and curing the anisotropic conductive material layer in a state where the thermocompression bonding head is in contact with the upper surface of the second connection target member. When,
A step of pulling up the thermocompression bonding head from the upper surface of the second connection target member,
In the step of curing the anisotropic conductive material layer, the components other than the conductive particles in the anisotropic conductive material layer are added to the electrode and the conductive material until the anisotropic conductive material layer reaches a curing start temperature. The manufacturing method of a connection structure which excludes from between conductive particles and forms the recessed part into which the said electroconductive particle was pushed in to the said electrode.   The manufacturing method of the connection structure of Claim 1 whose hardening start temperature of the said anisotropic conductive material layer is 50 degreeC or more and 100 degrees C or less.   The reaction rate of the thermosetting compound in the anisotropic conductive material layer or its cured product layer immediately after the thermocompression bonding head is pulled up from the upper surface of the second connection target member is 80% or more. A method for manufacturing the connection structure according to 1 or 2.   The anisotropic conductive material that lowers the thermocompression bonding head and uses the anisotropic conductive material that flows immediately after the lower surface of the thermocompression bonding head contacts the upper surface of the second connection target member is used as the anisotropic conductive material. The manufacturing method of the connection structure of any one of 1-3.   The time from when the thermocompression bonding head comes into contact with the upper surface of the second connection target member to when the thermocompression bonding head is pulled up from the upper surface of the second connection target member is 8 seconds or less. The manufacturing method of the connection structure of any one of these.

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