JP2012178460A - Method for manufacturing connection structure and coating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a connection structure in which position deviation between electrodes can be suppressed.SOLUTION: A method for manufacturing a connection structure 1 includes the steps of: forming an anisotropic conductive paste layer on a first connection target member 2 having an electrode 2b on an upper surface 2a by applying anisotropic conductive paste from a dispenser while moving the dispenser; removing at least a partial region in the anisotropic conductive paste layer using a removal device; laminating a second connection target member 4 having an electrode 4b on a lower surface 4a on the anisotropic conductive paste layer; and forming a hardened object layer 3 by heating and mainly hardening the anisotropic conductive paste layer. In the anisotropic conductive paste layer before removal by the removal device, a first region is removed by a removal device 14 or a second region with the more amount of application is removed by the removal device.

Description

  In the present invention, an anisotropic conductive paste is applied on a first connection target member, and the first connection target member and the second connection target member are formed by a cured product layer obtained by curing the anisotropic conductive paste. The present invention relates to a method for manufacturing a connection structure that connects the two. Moreover, this invention relates to the coating device used in order to apply | coat anisotropic conductive paste on the 1st connection object member.

  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.

  In order to obtain various connection structures, the anisotropic conductive paste is used, for example, for connection between a flexible printed circuit board and a glass substrate (FOG (Film on Glass)), connection between a semiconductor chip and a flexible printed circuit board (COF ( Chip on Film)), connection between a semiconductor chip and a glass substrate (COG (Chip on Glass)), connection between a flexible printed circuit board and a glass epoxy substrate (FOB (Film on Board)), and the like.

As an example of the manufacturing method of the connection structure, in Patent Document 1 below, a conductive adhesive having a minimum melt viscosity of 1.0 × 10 ³ Pa · s or less is placed on a wiring board, and the conductive The electrical component is heated by a thermocompression bonding head having a step of placing an electrical component having a thickness of 200 μm or less on an adhesive and a crimping portion using an elastomer having a rubber hardness of 60 or less. The manufacturing method of the connection structure provided with the process of thermocompression bonding on a board | substrate is disclosed. An anisotropic conductive paste containing a plurality of conductive particles or the like is used as the conductive adhesive.

  Patent Document 2 below discloses a method for manufacturing a connection structure in which connected members having opposing electrodes are connected by a cured product of a paste-like connection material disposed between them. In Patent Document 2, the paste-like connection material is 1.1 to 1.5 times the amount Y represented by the following formula (I), fills the gap in the connection region, and can cure the peripheral portion of the connection region. The paste-like connecting material is cured substantially uniformly in the region. An anisotropic conductive paste containing a plurality of conductive particles is used as the paste-like connecting material.

  Y = (height of the electrode of one connected member + height of the electrode of the other connected member) × area of the connection region (formula (I)

JP 2009-141269 A JP 2001-135672 A

  In the manufacturing method of the conventional connection structure as described in Patent Documents 1 and 2, the upper connection target member is laminated and temporarily pressure-bonded on the anisotropic conductive paste disposed on the lower connection target member. Later, the positional displacement of the connection target member between the upper side and the lower side may occur. If the upper and lower connection target members are misaligned, there is a problem that the position between the electrodes facing the upper and lower connection target members is deviated, resulting in low conduction reliability between the electrodes. Further, in the conventional connection structure manufacturing method, when the upper connection target member is laminated and pressure-bonded onto the anisotropic conductive paste disposed on the lower connection target member using the pressure-bonding head, An anisotropic conductive paste may adhere, or an anisotropic conductive paste may adhere to the side surface or upper surface of the upper connection target member. If the crimping head becomes dirty, the subsequently produced connection structure is contaminated.

  Moreover, in the conventional manufacturing method of the connection structure as described in Patent Documents 1 and 2, the conductive particles may not be accurately arranged between the electrodes. For this reason, in the connection structure obtained, there exists a problem that the conduction | electrical_connection reliability between electrodes becomes low.

  An object of the present invention is to provide a method for manufacturing a connection structure that can suppress a positional shift between the electrodes of the first and second connection target members and that can obtain a connection structure excellent in conduction reliability. is there.

  Moreover, the limited objective of this invention is to provide the manufacturing method of the connection structure which can suppress the contamination by anisotropic conductive paste.

  According to a wide aspect of the present invention, an anisotropic conductive paste containing a thermosetting component and conductive particles is applied from the dispenser while moving the dispenser onto a first connection target member having an electrode on the upper surface. A step of forming the anisotropic conductive paste layer, a step of removing at least a part of the anisotropic conductive paste layer by a removing device, and an electrode on the anisotropic conductive paste layer. A step of laminating the second connection target member on the lower surface, and a step of heating and anisotropically curing the anisotropic conductive paste layer to form a cured product layer, before being removed by the removing device The anisotropic conductive paste layer has a first region and a second region having a larger coating amount than the first region, and the first region is removed by the removing device, or The second area where the coating amount is large Is removed by serial remover, 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 2nd area | region with much said coating amount is removed by the said removal apparatus.

  In another specific aspect of the method for manufacturing a connection structure according to the present invention, the region where the anisotropic conductive paste layer is applied is removed by the removing device.

  In still another specific aspect of the method for manufacturing a connection structure according to the present invention, the second region is a region of an application end portion of the anisotropic conductive paste layer.

  In another specific aspect of the manufacturing method of the connection structure according to the present invention, a suction removal device that sucks and removes at least a part of the anisotropic conductive paste layer is used as the removal device.

  In the manufacturing method of the connection structure according to the present invention, it is preferable to use a coating apparatus in which the dispenser and the removing device are connected. Moreover, it is preferable to move the dispenser and the removing device in conjunction with each other.

  In another specific aspect of the method for manufacturing a connection structure according to the present invention, the anisotropy in the direction orthogonal to the application direction is a central portion of the anisotropic conductive paste layer in the direction orthogonal to the application direction. The anisotropic conductive paste is applied so that the outer edge of the central portion of the conductive paste layer has a raised shape.

  In another specific aspect of the method for producing a connection structure according to the present invention, an anisotropic conductive paste containing a thermosetting component is used as the anisotropic conductive paste, or a thermosetting component and a photocuring property are used. Using the anisotropic conductive paste containing the component, the anisotropic conductive paste layer is heated or irradiated with light to cure and form a B-staged anisotropic conductive paste layer A step of laminating the second connection target member on the upper surface of the B-staged anisotropic conductive paste layer, and heating the B-staged anisotropic conductive paste layer. This is cured to form a cured product layer.

  In still another specific aspect of the method for manufacturing a connection structure according to the present invention, the anisotropic conductive paste containing a thermosetting component and a photocurable component is used as the anisotropic conductive paste. Curing is advanced by irradiating light to the anisotropic conductive paste layer to form a B-staged anisotropic conductive paste layer, and the B-staged anisotropic conductive paste layer is heated to form Curing is performed to form a cured product layer.

  Further, according to a wide aspect of the present invention, there is provided a coating apparatus used for coating an anisotropic conductive paste containing a thermosetting component and conductive particles on a first connection target member, Dispenser for applying the anisotropic conductive paste on the first connection target member and at least a part of the region of the anisotropic conductive paste applied on the first connection target member And a removing device.

  In the coating device according to the present invention, it is preferable that the dispenser and the removing device are connected. It is preferable that the dispenser and the removing device are configured to move in conjunction with each other.

  In a specific aspect of the coating apparatus according to the present invention, an anisotropic conductive paste including a thermosetting component, a photocurable component, and conductive particles is applied onto the first connection target member, and the anisotropic A coating apparatus used for irradiating the conductive conductive paste with light, further comprising a light irradiation apparatus.

  In the manufacturing method of the connection structure according to the present invention, the anisotropic conductive paste layer is applied from the dispenser while moving the dispenser onto the first connection target member having the electrode on the upper surface. After forming, the second connection target member having at least a part of the anisotropic conductive paste layer removed by a removing device and then having an electrode on the lower surface on the anisotropic conductive paste layer The anisotropic conductive paste layer is further cured by heating the anisotropic conductive paste layer, so that the anisotropic conductive paste layer before being removed by the removing device further comprises the first region and the first region. Since the first region is removed by the removing device, or the second region having a large coating amount is removed by the removing device, the first region Between the electrodes of the second connection target member It can be suppressed location shift, it is possible to increase the conduction reliability between electrodes.

FIG. 1 is a partially cutaway 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. FIG. 2 is a plan view schematically showing a connection structure obtained by the method for manufacturing a connection structure according to one embodiment of the present invention. 3A to 3C are partially cutaway 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 partially cutaway front cross-sectional view for explaining a method for manufacturing a connection structure according to an embodiment of the present invention. 5 (a) and 5 (b) show an anisotropic conductive paste layer and B-stage before the B-stage using the coating apparatus in the method for manufacturing a connection structure according to an embodiment of the present invention. It is a schematic diagram for demonstrating the method of forming the subsequent anisotropic conductive paste layer. 6 (a) and 6 (b) show an anisotropic conductive paste layer and a B-stage before the B-stage using the coating apparatus in the manufacturing method of the connection structure according to an embodiment of the present invention. It is a schematic diagram for demonstrating the method of forming the subsequent anisotropic conductive paste layer. FIGS. 7A and 7B are schematic diagrams for explaining another example of the method of forming the anisotropic conductive paste layer before B-stage and the anisotropic conductive paste layer after B-stage. FIG. FIGS. 8A and 8B are schematic views for explaining another example of a method for forming an anisotropic conductive paste layer into a B-stage using a coating apparatus. FIG. 9 is a schematic diagram showing a modification of the application shape of the anisotropic conductive paste layer.

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

  In FIG. 1, the connection structure obtained by the manufacturing method of the connection structure which concerns on one Embodiment of this invention is typically shown with front sectional drawing. FIG. 2 is a plan view showing the connection structure shown in FIG. FIG. 1 shows a cross-sectional view taken along line II in the connection structure shown in FIG.

  The connection structure 1 shown in FIGS. 1 and 2 includes a cured product layer connecting the first connection target member 2, the second connection target member 4, and the first and second connection target members 2 and 4. 3. The cured product layer 3 is a connection part that connects the first and second connection target members 2 and 4. The cured product layer 3 is formed by curing an anisotropic conductive paste containing a thermosetting component and conductive particles 5. The anisotropic conductive paste includes a plurality of conductive particles 5.

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

  The connection structure 1 shown in FIGS. 1 and 2 can be obtained as follows. Here, as the anisotropic conductive paste, in addition to the thermosetting component and the conductive particles 5, a manufacturing method of the connection structure 1 when an anisotropic conductive paste further including a photocurable component is used. This will be specifically described.

  As shown in FIG. 3A, the first connection target member 2 having the first electrode 2b on the upper surface 2a is prepared. Next, an anisotropic conductive paste including a thermosetting component, a photocurable component, and conductive particles 5 is applied to the upper surface 2 a of the first connection target member 2, and the first connection target member 2 An anisotropic conductive paste layer 3A is formed on the upper surface 2a. Here, the anisotropic conductive paste is linearly applied to the upper surface 2a of the first connection target member 2. At this time, it is preferable that one or a plurality of conductive particles 5 be disposed on the electrode 2b.

  FIG. 4 and FIG. 5A show a state when applying the anisotropic conductive paste in a front sectional view and a side view. In order to form the anisotropic conductive paste layer 3A, a coating apparatus 11 shown in FIG. 5A is preferably used. In FIG. 4, the movement direction of the dispenser 12 and the application direction of the anisotropic conductive paste are directions from the back side toward the front side. In FIG. 5A, the moving direction of the dispenser 12 and the application direction of the anisotropic conductive paste are directions from the right side to the left side.

  The coating device 11 is used to apply an anisotropic conductive paste including a thermosetting component and conductive particles 5 on the first connection target member 2. The coating device 11 includes a dispenser 12, a light irradiation device 13 connected to the dispenser 12, and a removing device 14 connected to the dispenser 12. The dispenser 12 includes a syringe 12a for filling the inside with an anisotropic conductive paste, and a grip portion 12b that grips the outer peripheral surface of the syringe 12a. The light irradiation device 13 includes a light irradiation device main body 13a and a light irradiation unit 13b.

  The dispenser 11 is a dispenser for applying the anisotropic conductive paste onto the first connection target member 2. The light irradiation device 13 is a light irradiation device for applying the anisotropic conductive paste on the first connection target member 2 and irradiating the anisotropic conductive paste with light. The removing device 14 is a removing device for removing at least a part of the anisotropic conductive paste applied on the first connection target member 2.

  As shown in FIGS. 4 and 5 (a), when applying the anisotropic conductive paste, the upper surface 2a of the first connection target member 2 is moved while moving the coating device 11 in the direction of the arrow A. An anisotropic conductive paste is applied from the syringe 12a of the dispenser 12 to form the anisotropic conductive paste layer 3A.

  When the anisotropic conductive paste layer 3A is formed, the upper surface 2a of the first connection target member 2 and the tip 12c of the dispenser 12 are set when the maximum thickness (μm) of the anisotropic conductive paste layer 3A is T1. It is preferable to apply the anisotropic conductive paste from the dispenser 12 so that the distance (μm) to the distance is less than T1. That is, the distance (μm) between the upper surface 2a of the first connection target member 2 and the tip 12c of the dispenser 12 is preferably less than the maximum thickness T1 (μm) of the anisotropic conductive paste layer 3A. The anisotropic conductive paste is discharged from the tip 12c of the dispenser 12. By making the distance (μm) less than the maximum thickness T1 (μm), for example, the anisotropic conductive paste can be applied by being pushed in. In this way, by applying the anisotropic conductive paste to the upper surface 2a of the first connection target member 2 from the dispenser 12, the first and second connection target members 2 and 4 are connected to the first and second connection target members 2 and 4, respectively. The positional deviation between the electrodes 2b and 4b can be effectively suppressed. Here, the maximum thickness T1 (μm) of the anisotropic conductive paste layer 3A does not include the thickness of the portion removed by the removing device.

  From the viewpoint of further suppressing the displacement between the first and second electrodes 2b and 4b of the first and second connection target members 2 and 4, the upper surface 2a of the first connection target member 2 and the dispenser 12 The distance (μm) from the tip 12c is more preferably 0.99T1 or less, further preferably 0.95T1 or less, preferably 0.6T1 or more, more preferably 0.7T1 or more, and further preferably 0.8T1 or more. . Further, the distance (μm) between the upper surface 2a of the first connection target member 2 and the tip 12c of the dispenser 12 may be 1T or more. The maximum value (μm) of the distance (μm) between the upper surface 2a of the first connection target member 2 and the tip 12c of the dispenser 12 is about 10T.

  Further, when forming the anisotropic conductive paste layer 3A, as shown in FIG. 4, in the central portion 3x of the anisotropic conductive paste layer 3A in the direction orthogonal to the application direction (S direction shown in FIG. 2). On the other hand, it is preferable to apply the anisotropic conductive paste so that the outer edge 3y of the central portion 3x of the anisotropic conductive paste layer 3A in the direction orthogonal to the application direction has a raised shape F. The anisotropic conductive paste layer 3A immediately after application applied on the first connection target member 2 has a central portion 3x of the anisotropic conductive paste layer 3A in a direction orthogonal to the application direction (the S direction shown in FIG. 2). On the other hand, it is preferable that the outer edge 3y of the central portion 3x of the anisotropic conductive paste layer 3A in the direction orthogonal to the coating direction has a raised shape F. In this case, the displacement between the first and second electrodes 2b and 4b of the first and second connection target members 2 and 4 can be further suppressed.

  When the maximum thickness (μm) of the anisotropic conductive paste layer 3A is T1, the distance (μm) between the upper surface 2a of the first connection target member 2 and the tip 12c of the dispenser 12 is less than T1, By applying the anisotropic conductive paste from the dispenser 12, it is easy to make the anisotropic conductive paste layer 3A have the shape F. The upper surface 3a of the central portion 3x of the anisotropic conductive paste layer 3A is concave with respect to the upper surface 3a of the edge portion 3y in a direction orthogonal to the application direction. The upper surface 3a of the edge 3y of the anisotropic conductive paste layer 3A is in a direction orthogonal to the application direction. Convex with respect to the central portion 3x. Note that the thick edge portion 3y is not removed in the removing step by the removing device 14 described later. However, the thick edge 3y may be removed. Although the edge portion 3y is slightly thicker, the amount of application tends to increase in the paste reservoir portion or the application end portion region described later, and the thickness of the paste reservoir portion or application end portion region tends to be considerably thicker.

  When the average thickness (μm) of the anisotropic conductive paste layer 3A is T, the anisotropic conductive paste layer 3A has a maximum thickness T1 (μm) of more than 1T and 2T or less and anisotropic The anisotropic conductive paste is preferably applied from the dispenser 12 so that the minimum thickness T2 (μm) of the conductive paste layer 3A is 0.8T or more and less than 1T. By satisfying such preferable maximum thickness T1 and minimum thickness T2, the displacement between the first and second electrodes 2b and 4b of the first and second connection target members 2 and 4 can be further suppressed.

The thickness difference between the maximum thickness T1 (μm) and the minimum thickness T2 (μm) of the upper surface 3a of the anisotropic conductive paste layer 3A is preferably 40 μm or less, more preferably 25 μm or less, and still more preferably 18 μm or less. By controlling to such a preferable thickness difference, the displacement between the first and second electrodes 2b and 4b of the first and second connection target members 2 and 4 can be further suppressed.
Here, the average thickness T (μm), the maximum thickness T1 (μm), and the minimum thickness T2 (μm) of the anisotropic conductive paste layer 3A do not include the thickness of the portion removed by the removing device. .

  FIG. 9 is a schematic diagram showing a modification of the application shape of the anisotropic conductive paste layer 3A shown in FIG.

  When forming the anisotropic conductive paste layer 51A immediately after application (before the B-stage) shown in FIG. 9, for example, compared with the case of forming the anisotropic conductive paste layer 3A of FIG. The isotropic conductive paste is applied so as to be pushed further. As a result, the edge portion 51y is further raised with respect to the central portion 51x. Note that the upper surface 51a of the central portion 51x of the anisotropic conductive paste layer 51A is flat in a direction orthogonal to the application direction and is linear. The upper surface 51a of the edge portion 51y is convex in a direction orthogonal to the application direction.

  When the anisotropic conductive paste is applied using the dispenser 11, regions having different application amounts are easily formed in the movement direction of the dispenser 11 and the application direction of the anisotropic conductive paste. In the anisotropic conductive paste layer 3A shown in FIG. 5B, a first region R1 and a second region R2 having a larger coating amount than the first region R1 are formed. That is, the anisotropic conductive paste layer 3A before being removed by the removing device has the first region R1 and the second region R2 having a larger application amount than the first region R1. Here, the second region R2 having a large coating amount is a region at the coating end portion. As described above, at the end of the application, the anisotropic conductive paste discharged from the tip 12c of the dispenser 12 is partially concentrated so that the paste reservoir is easily formed, and the second region R2 having a large application amount is formed. Easy to form.

  Therefore, as shown in FIG. 6A, at least a part of the anisotropic conductive paste layer 3 </ b> A is moved in the direction indicated by the arrow C and removed by the removing device 14. Here, the removal device 14 removes the region of the application end portion, which is the second region R2 where the application amount is large, from the tip 14a. Thereby, the difference in the partial application amount of the anisotropic conductive paste layer 3A can be reduced. For this reason, in the connection structure 1 obtained, the position shift between the 1st, 2nd electrodes 2b and 4b of the 1st, 2nd connection object members 2 and 4 can be suppressed. The thickness of the second region R2 having a large coating amount is preferably a second region that is thicker than the first region. In this case, the partial thickness difference of the anisotropic conductive paste layer 3A can be reduced. By reducing the thickness difference, the positional deviation between the first and second electrodes 2b and 4b of the first and second connection target members 2 and 4 can be further suppressed.

  Further, by removing the second region R2 having a large coating amount, the anisotropic conductive paste layer 3A adheres to the side surface or the upper surface of the second connection target member 4, or the second connection target member 4 It can suppress adhering to the pressure bonding head used at the time of lamination pressure bonding. In particular, contamination can be remarkably suppressed by removing a thick region. By suppressing the adhesion of the anisotropic conductive paste layer 3A to the pressure bonding head, it is possible to suppress contamination of the connection structure that is subsequently manufactured using the pressure bonding head. For this reason, a connection structure with reduced contamination can be continuously produced.

  As shown in FIGS. 7A to 7B, when the anisotropic conductive paste is applied using the dispenser 11, the initial application in the moving direction of the dispenser 11 and the application direction of the anisotropic conductive paste. In the stage, a first region R1 having a small coating amount and a second region R2 having a larger coating amount than the first region R1 may be formed. The first region R1 with a relatively small application amount is a region where the application is started. The first region R1 having a small coating amount is preferably a first region having a small thickness, and the second region R2 having a large coating amount is preferably a second region having a large thickness. As described above, at the start of application, the anisotropic conductive paste discharged from the tip 12c of the dispenser 12 is small, the paste thin layer portion is easily formed, and the first region R1 with a small application amount may be formed. . In such a case, as shown in FIG. 7B, the region of the first region R1 and the application start portion can be moved in the direction indicated by the arrow C and removed by the removing device 14. preferable. Also by this, the difference in the partial application amount or the thickness difference of the anisotropic conductive paste layer 3A can be reduced. For this reason, in the connection structure 1 obtained, the position shift between the 1st, 2nd electrodes 2b and 4b of the 1st, 2nd connection object members 2 and 4 can be suppressed.

  The removal device 14 is preferably a suction removal device that sucks and removes at least a part of the anisotropic conductive paste layer 3A. The removing device 14 is preferably a suction removing device that sucks and removes the first region R1 of the anisotropic conductive paste layer 3A or sucks and removes the second region R2 having a large coating amount. . In this case, the anisotropic conductive paste layer 3A can be partially and effectively removed.

  The region of the anisotropic conductive paste layer 3 </ b> A removed by the removing device 14 is preferably a coating start portion region or a coating end portion region, and is preferably a coating end portion region. The anisotropic conductive paste layer 3A removed by the removing device 14 is preferably a paste reservoir or a paste thin layer, and more preferably a paste reservoir.

  In the coating device 11, the grip portion 12 b and the removal device 14 are connected. Accordingly, the dispenser 12 and the removing device 14 can be moved in conjunction with each other, and the dispenser 12 and the removing device 14 can be moved at the same speed. Furthermore, the distance between the dispenser 12 and the removal device 14 can be reduced, that is, the distance between the discharge portion of the dispenser 12 and the removal device 14 can be reduced. As a result, at least a part of the anisotropic conductive paste layer 3 </ b> A applied by the dispenser 12 can be efficiently and effectively removed by the removing device 14. In addition, the syringe 12a and the removal apparatus 14 may be directly connected.

  Next, the anisotropic conductive paste layer 3 </ b> A is cured by irradiating light to the anisotropic conductive paste layer 3 </ b> A from which at least a part of the region has been removed by the removing device 14. Curing of the anisotropic conductive paste layer 3A is advanced to make the anisotropic conductive paste layer 3A B-staged. As shown in FIGS. 3B, 5B and 6A, 6B, the upper surface 2a of the first connection target member 2 is formed by forming the anisotropic conductive paste layer 3A into a B-stage. The B-staged anisotropic conductive paste layer 3B is formed.

  As shown in FIG. 5B and FIG. 6A, when irradiating light, anisotropy is indicated from the light irradiation part 13b of the light irradiation device 13 connected to the dispenser 12 as indicated by an arrow B. The conductive paste layer 3A is irradiated with light. Here, as shown by an arrow B, the anisotropic conductive paste layer 3A is irradiated with light from the light irradiation unit 13b of the light irradiation device 13 connected to the dispenser 12 while applying the anisotropic conductive paste. . Thus, it is preferable to irradiate light while applying the anisotropic conductive paste.

  It is preferable to irradiate the anisotropic conductive paste layer 3 </ b> A with light while disposing the anisotropic conductive paste on the upper surface 2 a of the first connection target member 2. Furthermore, it is also preferable to irradiate the anisotropic conductive paste layer 3A with light at the same time as or immediately after the application of the anisotropic conductive paste to the upper surface 2a of the first connection target member 2. When the application and the light irradiation are performed as described above, the flow of the anisotropic conductive paste layer can be further suppressed. For this reason, the connection reliability of the 1st, 2nd connection object member and the conduction | electrical_connection reliability between electrodes can be improved further. From the viewpoint of controlling the time until light irradiation with high accuracy, it is preferable to move the dispenser 12 and the light irradiation device 13, and it is preferable to move the dispenser 12 and the light irradiation device 13 in conjunction with each other. 12 and the light irradiation device 13 are preferably moved at the same speed. As described above, it is preferable to apply the anisotropic conductive paste while moving the dispenser 12 and the light irradiation device 13 to irradiate the anisotropic conductive paste layer 3 </ b> A with light. The time from the application of the anisotropic conductive paste to the upper surface 2a of the first connection target member 2 to the irradiation of light is 0 second or longer, preferably 3 seconds or shorter, more preferably 2 seconds or shorter. However, the table 31 may be moved in the direction opposite to the arrow A without moving the coating apparatus 11.

  In the coating device 11, the dispenser 12 and the light irradiation device 13 are connected by connecting the grip portion 12b and the light irradiation device main body 13a. Accordingly, the dispenser 12 and the light irradiation device 13 can be moved in conjunction with each other, and the dispenser 12 and the light irradiation device 13 can be moved at the same speed. Furthermore, the distance between the dispenser 12 and the light irradiation device 13 can be reduced, that is, the distance between the discharge part of the dispenser 12 and the light irradiation part 13b can be reduced. As a result, the anisotropic conductive paste layer 3A applied by the dispenser 12 can be quickly irradiated with light. In addition, the syringe 12a and the light irradiation apparatus main body 13a may be directly connected.

  In order to irradiate the anisotropic conductive paste layer 3 </ b> A with light, a dispenser 12 and a light irradiation device 21 not connected to the dispenser 12 may be used as shown in FIG. 8A. Similar to the light irradiation device 13, the light irradiation device 21 includes a light irradiation device main body 21 a and a light irradiation unit 21 b. The light irradiation device 21 is configured to irradiate light over a wider area than the light irradiation device 13.

  When using the dispenser 12 and the light irradiation device 21 not connected to the dispenser 12, for example, as shown in FIG. 8A, the light irradiation device 21 is placed above the first connection target member 2. Deploy. Next, while the dispenser 12 is moved in the direction of the arrow A between the first connection target member 2 and the light irradiation device 21, anisotropic conduction is performed from the syringe 12 a to the upper surface 2 a of the first connection target member 2. The paste is applied to form the anisotropic conductive paste layer 3A. Next, as shown in FIG. 8 (b), after the application of the anisotropic conductive paste is completed, an arrow is emitted from the light irradiation unit 21b of the light irradiation device 21 disposed above the first connection target member 2. As shown by B, the anisotropic conductive paste layer 3A is irradiated with light. The light irradiation is performed, for example, simultaneously with the application of the anisotropic conductive paste or immediately after the application.

  The light irradiation device 21 is preferably disposed above the first connection target member 2 during application. In this case, light can be irradiated quickly after application. After application, it is preferable to irradiate the entire region of the anisotropic conductive paste layer 3A with light. In this case, the anisotropic conductive paste layer 3A can be made B-stage more uniformly.

  By using the coating device 11 and the light irradiation device 21 shown in FIG. 5 (a) or FIG. 8 (a), or simultaneously with the application of the anisotropic conductive paste to the upper surface 2a of the first connection target member 2, Immediately thereafter, the anisotropic conductive paste layer 3A can be easily irradiated with light.

The light irradiation intensity for causing the anisotropic conductive paste layer 3 </ ^b > A to be B-staged by light irradiation and causing the curing to proceed appropriately is, for example, preferably about 0.1 to 100 mW / cm ² . Moreover, the light irradiation energy for advancing moderately curing the anisotropic conductive paste layer 3A is preferably 50 mJ / cm ² or more, more preferably 100 mJ / cm ² or more, preferably 10000 mJ / cm ² or less, more Preferably it is 2000 mJ / cm ² or less.

  The light source used when irradiating light is not specifically limited. Examples of the light source include a light source having a sufficient light emission distribution at a wavelength of 420 nm or less. Specific examples of the light source include, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a chemical lamp, a black light lamp, a microwave excitation mercury lamp, and a metal halide lamp.

  Alternatively, the anisotropic conductive paste layer 3A may be B-staged by applying heat, without making the anisotropic conductive paste layer 3A B-staged by light irradiation. When hardening is performed by applying heat to the anisotropic conductive paste layer 3A to make the anisotropic conductive paste layer 3A B-stage, the anisotropic conductive paste layer 3A is appropriately B-staged. The heating temperature for this is preferably 80 ° C or higher, preferably 150 ° C or lower, more preferably 120 ° C or lower. Even when the anisotropic conductive paste layer 3A is B-staged by application of heat instead of light irradiation, as described above, if at least a part of the anisotropic conductive paste layer 3A is removed by the removing device 14, The positional deviation between the first and second electrodes 2b and 4b can be suppressed.

  Next, as shown in FIG.3 (c), the 2nd connection object member 4 is dropped on the upper surface 3a of the B-staged anisotropic conductive paste layer 3B, and the 2nd connection object member 4 is attached. Laminate. The second connection target member 4 is laminated so that the first electrode 2b on the upper surface 2a of the first connection target member 2 and the second electrode 4b on the lower surface 4a of the second connection target member 4 face each other. To do. In addition, after laminating | stacking the 2nd connection object member 4, in order to make anisotropic conductive paste layer 3A into B stage, you may irradiate light and may provide heat | fever. However, it is preferable to apply heat or irradiate light in order to make the anisotropic conductive paste layer 3A into a B-stage after the second connection target member 4 is laminated.

  Further, when the second connection target member 4 is laminated, the B-staged anisotropic conductive paste layer 3 </ b> B is heated and fully cured to form the cured product layer 3. However, the anisotropic conductive paste layer 3B may be heated before the second connection target member 4 is laminated. However, it is preferable that the anisotropic conductive paste layer 3 </ b> B is heated to be fully cured after the second connection target member 4 is laminated.

  The heating temperature for sufficiently curing the anisotropic conductive paste layer 3B is preferably 160 ° C. or higher, preferably 250 ° C. or lower, more preferably 200 ° C. or lower.

  When the anisotropic conductive paste layer 3A is not B-staged without applying heat or irradiating light to the anisotropic conductive paste layer 3A, the second surface is applied to the upper surface 3a of the anisotropic conductive paste layer 3A. The connection target member 4 may be laminated, and the anisotropic conductive paste layer 3A may be heated to be fully cured.

  It is preferable to apply pressure when the anisotropic conductive paste layer 3B is cured. By compressing the conductive particles 5 with the first electrode 2b and the second electrode 4b by pressurization, the contact area between the first and second electrodes 2b, 4b and the conductive particles 5 can be increased. it can. For this reason, conduction reliability can be improved.

  By curing the anisotropic conductive paste layer 3 </ b> B, the first connection target member 2 and the second connection target member 4 are connected via the cured product layer 3. Further, the first electrode 2 b and the second electrode 4 b are electrically connected through the conductive particles 5. In this way, the connection structure 1 shown in FIG. 1 can be obtained. In this embodiment, since photocuring and thermosetting are used together, the anisotropic conductive paste can be cured in a short time.

  In addition, when the connection structure is manufactured, the anisotropic conductive paste is B-staged by applying heat or irradiating light, and then is cured to provide anisotropy disposed on the first connection target member. The conductive particles contained in the paste layer are difficult to flow greatly in the curing stage. Accordingly, the conductive particles are easily arranged in a predetermined region. Specifically, conductive particles can be arranged between upper and lower electrodes to be connected, and adjacent electrodes that should not be connected are electrically connected via a plurality of conductive particles. Can be suppressed. For this reason, the conduction | electrical_connection reliability between the electrodes in a connection structure can be improved.

  In addition, when the anisotropic conductive paste is made into a B stage by applying heat or irradiating light during the production of the connection structure, the surface of the anisotropic conductive paste layer before the B stage is made large There is a tendency that the first and second electrodes are liable to be displaced due to the influence of the shape of the part or the shape of the recess. For example, in the B-staged anisotropic conductive paste layer, the viscosity has increased to some extent due to the B-stage. For example, there is a large protrusion or recess on the upper surface of the B-staged anisotropic conductive paste layer. If it exists, in the connection structure obtained, there exists a tendency for the position shift between the electrodes in the 1st, 2nd connection object member to arise easily.

  On the other hand, even if it changed into B stage by removing the area | region where a coating amount differs from another area | region, or a big convex part or recessed part with the said removal apparatus 14, it is an electrode in the 1st, 2nd connection object member The positional deviation between them can be effectively suppressed.

  On the other hand, the viscosity of the anisotropic conductive paste layer before the B-stage is too low when the anisotropic conductive paste is not B-staged by applying heat or irradiating the light at the time of producing the connection structure. Thus, in the obtained connection structure, there is a tendency that displacement between the electrodes in the first and second connection target members is likely to occur.

  On the other hand, when the connection structure is produced, the anisotropic conductive paste is made into a B-stage by applying heat or irradiating light, so that the positional deviation between the electrodes in the first and second connection target members is reduced. It can be effectively suppressed.

  The connection structure manufacturing method according to the present invention 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)), It can be used for connection between a semiconductor chip and a glass substrate (COG (Chip on Glass)), connection between a flexible printed circuit board and a glass epoxy substrate (FOB (Film on Board)), or the like. Especially, the manufacturing method of the connection structure concerning the present invention is suitable for COG use. In the manufacturing method of the connection structure according to the present invention, it is preferable to use a semiconductor chip and a glass substrate as the first connection target member and the second connection target member.

  In COG applications, in particular, it is often difficult to reliably connect the electrodes of the semiconductor chip and the glass substrate with the conductive particles of the anisotropic conductive paste. For example, in the case of COG use, the distance between adjacent electrodes of a semiconductor chip and the distance between adjacent electrodes of a glass substrate may be about 10 to 20 μm, and fine wiring is often formed. Even if fine wiring is formed, the manufacturing method of the connection structure according to the present invention can suppress misalignment between the electrodes and can accurately arrange the conductive particles between the electrodes. And the glass substrate can be connected with high accuracy, and the conduction reliability can be improved.

  The anisotropic conductive paste includes a thermosetting component and conductive particles. The thermosetting component preferably contains a thermosetting compound and a thermosetting agent. The anisotropic conductive paste preferably further includes a photocurable component in addition to the thermosetting component. The photocurable component preferably contains a photocurable compound and a photocuring initiator. The anisotropic conductive paste preferably contains a thermosetting compound as a curable compound and further contains a photocurable compound. The thermosetting compound is preferably a compound having an epoxy group or a thiirane group. The photocurable compound is preferably a compound having a (meth) acryloyl group.

  Hereinafter, each component contained in the anisotropic conductive paste and details of each component preferably contained will be described.

[Thermosetting compound]
The thermosetting compound has thermosetting properties. As for the said thermosetting compound, only 1 type may be used and 2 or more types may be used together.

  Examples of the thermosetting compound include oxetane compounds, 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 paste or further improving the conduction reliability in the connection structure, the thermosetting compound is a thermosetting compound having an epoxy group or a thiirane group. It is preferable that a thermosetting compound having a thiirane group is included. The thermosetting compound having an epoxy group is an epoxy compound. The thermosetting compound having a thiirane group is an episulfide compound. From the viewpoint of enhancing the curability of the anisotropic conductive paste, the content of the compound having an epoxy group or thiirane group is preferably 10% by weight or more, more preferably 20% by weight in 100% by weight of the thermosetting compound. % Or more and 100% by weight or less. The total amount of the thermosetting compound may be a compound having the epoxy group or thiirane group.

  Since the episulfide compound has a thiirane group instead of an epoxy group, it can be quickly cured 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.

  The thermosetting compound having an epoxy group or thiirane group preferably has an aromatic ring. Examples of the aromatic ring include a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, tetracene ring, chrysene ring, triphenylene ring, tetraphen ring, pyrene ring, pentacene ring, picene ring, and perylene ring. Especially, it is preferable that the said aromatic ring is a benzene ring, a naphthalene ring, or an anthracene ring, and it is more preferable that it is a benzene ring or a naphthalene ring. A naphthalene ring is preferred because it has a planar structure and can be cured more rapidly.

[Photocurable compound]
The anisotropic conductive paste preferably contains a photocurable compound so as to be cured by irradiation with light. The photocurable compound can be semi-cured (B-staged) by irradiation with light to reduce the fluidity of the anisotropic conductive paste.

  The photocurable compound is not particularly limited, and examples thereof include a photocurable compound having a (meth) acryloyl group and a photocurable compound having a cyclic ether group.

  The photocurable compound is preferably a photocurable compound having a (meth) acryloyl group. By using the photocurable compound having a (meth) acryloyl group, the conduction reliability of the connection structure can be further enhanced. From the viewpoint of effectively increasing the conduction reliability of the resulting connection structure, the photocurable compound preferably has one or two (meth) acryloyl groups.

  The photocurable compound having the (meth) acryloyl group has no epoxy group and thiirane group, and has a (meth) acryloyl group, and has an epoxy group or thiirane group, and ( The photocurable compound which has a (meth) acryloyl group is mentioned.

  As a photocurable compound having the above (meth) acryloyl group, an ester compound obtained by reacting a compound having (meth) acrylic acid and a hydroxyl group, an epoxy obtained by reacting (meth) acrylic acid and an epoxy compound. (Meth) acrylate or urethane (meth) acrylate obtained by reacting a (meth) acrylic acid derivative having a hydroxyl group with isocyanate is preferably used. The “(meth) acryloyl group” refers to an acryloyl group and a methacryloyl group. The “(meth) acryl” refers to acryl and methacryl. The “(meth) acrylate” refers to acrylate and methacrylate.

  The ester compound obtained by making the said (meth) acrylic acid and the compound which has a hydroxyl group react is not specifically limited. As the ester compound, any of a monofunctional ester compound, a bifunctional ester compound, and a trifunctional or higher functional ester compound can be used.

  The photocurable compound having the epoxy group or thiirane group and having a (meth) acryloyl group is a part of the epoxy group or part of thiirane of the compound having two or more epoxy groups or two or more thiirane groups. It is preferable that it is a photocurable compound obtained by converting a group into a (meth) acryloyl group. Such a photocurable compound is a partially (meth) acrylated epoxy compound or a partially (meth) acrylated episulfide compound.

  The photocurable compound is preferably a reaction product of a compound having two or more epoxy groups or two or more thiirane groups and (meth) acrylic acid. This reaction product is obtained by reacting a compound having two or more epoxy groups or two or more thiirane groups with (meth) acrylic acid in the presence of a basic catalyst according to a conventional method. It is preferable that 20% or more of the epoxy group or thiirane group is converted (converted) to a (meth) acryloyl group. The conversion is more preferably 30% or more, preferably 80% or less, more preferably 70% or less. Most preferably, 40% or more and 60% or less of the epoxy group or thiirane group is converted to a (meth) acryloyl group.

  Examples of the partially (meth) acrylated epoxy compound include bisphenol type epoxy (meth) acrylate, cresol novolac type epoxy (meth) acrylate, carboxylic acid anhydride-modified epoxy (meth) acrylate, and phenol novolac type epoxy (meth) acrylate. Is mentioned.

  Even if it uses the modified phenoxy resin which converted some epoxy groups or some thiirane groups of the phenoxy resin which has two or more epoxy groups or two or more thiirane groups into a (meth) acryloyl group as a photocurable compound. Good. That is, a modified phenoxy resin having an epoxy group or thiirane group and a (meth) acryloyl group may be used.

  Further, the photocurable compound may be a crosslinkable compound or a non-crosslinkable compound.

  Specific examples of the crosslinkable compound include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, (poly ) Ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, glycerol methacrylate acrylate, pentaerythritol tri (meth) acrylate, tri Examples include methylolpropane trimethacrylate, allyl (meth) acrylate, vinyl (meth) acrylate, divinylbenzene, polyester (meth) acrylate, and urethane (meth) acrylate.

  Specific examples of the non-crosslinkable compound include ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) ) Acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, decyl (Meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, and the like.

  When using a photocurable compound, the compounding ratio of a photocurable compound and a thermosetting compound is suitably adjusted according to the kind of a photocurable compound and a thermosetting compound. The anisotropic conductive paste preferably contains a photocurable compound and a thermosetting compound in a weight ratio of 1:99 to 90:10, more preferably 5:95 to 70:30, More preferably, it is included at 10:90 to 50:50. The anisotropic conductive paste particularly preferably contains a photocurable compound and a thermosetting compound in a weight ratio of 1:99 to 50:50.

(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 paste 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. Moreover, since the storage stability of anisotropic conductive paste can be improved, a latent hardener is preferable. 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 imidazole curing agent is not particularly limited, and 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2, 4-Diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine and 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s- Examples include triazine isocyanuric acid adducts.

  The polythiol curing agent is not particularly limited, and examples include trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, and dipentaerythritol hexa-3-mercaptopropionate. .

  The amine curing agent is not particularly limited, and hexamethylene diamine, octamethylene diamine, decamethylene diamine, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraspiro [5.5]. Examples include undecane, bis (4-aminocyclohexyl) methane, metaphenylenediamine, and diaminodiphenylsulfone.

  The content of the thermosetting agent is not particularly limited. The content of the thermosetting agent with respect to 100 parts by weight of the thermosetting compound in the curable compound is preferably 5 parts by weight or more, more preferably 10 parts by weight or more, and preferably 40 parts by weight or less. The amount is preferably 30 parts by weight or less, more preferably 20 parts by weight or less. 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 paste can be sufficiently thermoset.

(Photocuring initiator)
The photocuring initiator is not particularly limited. A conventionally known photocuring initiator can be used as the photocuring initiator. As for the said photocuring initiator, only 1 type may be used and 2 or more types may be used together.

  The photocuring initiator is not particularly limited, and examples thereof include acetophenone photocuring initiator, benzophenone photocuring initiator, thioxanthone, ketal photocuring initiator, halogenated ketone, acyl phosphinoxide, and acyl phosphonate. .

  Specific examples of the acetophenone photocuring initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, methoxy Examples include acetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, and 2-hydroxy-2-cyclohexylacetophenone. Specific examples of the ketal photocuring initiator include benzyldimethyl ketal.

  The content of the photocuring initiator is not particularly limited. The content of the photocuring initiator with respect to 100 parts by weight of the photocurable compound in the curable compound is preferably 0.1 parts by weight or more, more preferably 0.2 parts by weight or more, preferably 2 It is 1 part by weight or less, more preferably 1 part by weight or less. When the content of the photocuring initiator is not less than the above lower limit and not more than the above upper limit, the anisotropic conductive paste can be appropriately photocured. The anisotropic conductive paste can be prevented from flowing by irradiating the anisotropic conductive paste with light to form a B stage.

(Conductive particles)
The conductive particles contained in the anisotropic conductive paste 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 obtained by coating the surfaces of organic particles, inorganic particles, organic-inorganic hybrid particles, or metal particles with a metal layer, and metal particles that are substantially composed of only 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, and 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, still more preferably 15 μm or less, and particularly preferably 10 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. The content of the conductive particles in 100% by weight of the anisotropic conductive paste is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, still more preferably 1% by weight or more, preferably 40% by weight. % Or less, more preferably 30% by weight or less, still more preferably 19% 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 paste preferably contains a filler. By using the filler, latent heat expansion of the cured product of the anisotropic conductive paste 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 paste 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 paste may contain a solvent. By using the solvent, the viscosity of the anisotropic conductive paste 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.

  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.

  In the examples and comparative examples, the following materials were used.

Example 1
(1) Preparation of anisotropic conductive paste An episulfide compound-containing mixture containing 70% by weight of resorcinol diglycidyl ether and 30% by weight of an episulfide compound having a structure represented by the following formula (1B) was prepared.

  15 parts by weight of the above-described episulfide compound-containing mixture, 3 parts by weight of an amine adduct (“PN-23J” manufactured by Ajinomoto Fine Techno Co.) as a thermosetting agent, and an epoxy acrylate (“EBECRYL 3702” manufactured by Daicel Cytec Co., Ltd.) as a photocurable compound ”) 8 parts by weight, 0.2 part by weight of an acylphosphine oxide compound (“ DAROCUR TPO ”manufactured by Ciba Japan) as a photopolymerization initiator, and 2-ethyl-4-methylimidazole 1 as a curing accelerator Parts by weight, 20 parts by weight of silica having an average particle diameter of 0.25 μm and 20 parts by weight of alumina having an average particle diameter of 0.5 μm, and 100% by weight of conductive particles having an average particle diameter of 3 μm After adding so that the content in the inside becomes 10% by weight, it is 5 minutes at 2000 rpm using a planetary stirrer. By stirring, to obtain a formulation.

  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 having an ITO electrode pattern with L / S of 15 μm / 15 μm formed on the upper surface was prepared. A semiconductor chip was prepared in which a copper electrode pattern having an L / S of 15 μm / 15 μm and an electrode area of 1500 μm ² was formed on the lower surface.

  Moreover, the coating apparatus 11 shown in FIG.4 and FIG.5 (a) was prepared. The coating device includes a dispenser, a removing device connected to the dispenser, and an ultraviolet irradiation lamp that is a light irradiation device connected to the dispenser. Here, a suction removal device was used.

  While moving the coating device, the distance (μm) between the upper surface of the transparent glass substrate (first connection target member) and the tip of the dispenser is set as shown in Table 1 below, The obtained anisotropic conductive paste was applied to the film, and the average thickness T (μm), maximum thickness T1 (μm) and minimum thickness T2 (μm) (average thickness T (μm), maximum thickness T1 (μm) and minimum The thickness T2 (μm) does not include the thickness of the coating-completed portion that is the portion removed by the removing device), as shown in Table 1 below, to form an anisotropic conductive paste layer.

  Also, the application of the anisotropic conductive paste layer to the average thickness T (μm) of the anisotropic conductive paste layer (not including the thickness of the region where the application is completed, which is a portion removed by the removing device), is completed. The thickness T3 (μm) of the partial region was a magnification shown in Table 1 below. In addition, since the application amount of the anisotropic conductive paste in the region of the application end portion of the anisotropic conductive paste layer was larger than the application amount in the other regions, the thickness was thick.

  In Example 1 and Examples 2 to 5 to be described later, the anisotropic conductive paste layer in the direction orthogonal to the application direction with respect to the central portion of the anisotropic conductive paste layer in the direction orthogonal to the application direction. The anisotropic conductive paste was applied so that the outer edge of the central portion was raised.

  Then, the area | region of the said application | coating end part with much coating amount was attracted | sucked and removed using the said suction removal apparatus, moving the coating device.

Next, the anisotropic conductive paste layer from which the region where the coating has been completed is removed is irradiated with ultraviolet rays using an ultraviolet irradiation lamp so that the irradiation energy is 100 mJ / cm ^2, and anisotropic conductive is performed by photopolymerization. The paste layer was semi-cured and B-staged. Next, the semiconductor chip was stacked on the B-staged anisotropic conductive paste layer so that the electrodes face each other. Then, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer becomes 185 ° C., a pressure heating head is placed on the upper surface of the semiconductor chip and a pressure of 3 MPa is applied to form the anisotropic conductive paste layer. Completely cured at 185 ° C. to obtain a connection structure.

(Examples 2 to 7)
When producing the connection structure, the distance T2 (μm) between the upper surface of the transparent glass substrate and the tip of the dispenser is set as shown in Table 1 below, and the discharge speed and discharge of the anisotropic conductive paste are further set. Adjusting the amount, the application of the anisotropic conductive paste layer to the average thickness T (μm), the maximum thickness T1 (μm) and the minimum thickness T2 (μm), and the average thickness T (μm) of the anisotropic conductive paste layer is completed. A connection structure was obtained in the same manner as in Example 1 except that the magnification of the thickness T3 (μm) of the partial region was set as shown in Table 1 below.

(Comparative Examples 1-3)
When producing the connection structure, the distance (μm) between the upper surface of the transparent glass substrate and the tip of the dispenser is set as shown in Table 1 below, and the discharge speed and discharge amount of the anisotropic conductive paste are set. To complete the average thickness T (μm), maximum thickness T1 (μm) and minimum thickness T2 (μm) (average thickness T (μm), maximum thickness T1 (μm) and minimum thickness T2 (μm) The thickness of the portion of the anisotropic conductive paste layer with respect to the average thickness T (μm) of the anisotropic conductive paste layer (not including the thickness of the portion of the coating end portion). The connection structure was formed in the same manner as in Example 1 except that the magnification of the region thickness T3 (μm) was set as shown in Table 1 below, and that the region at the end of the coating was not removed by the removal device. Obtained.

(Evaluation)
(1) Presence / absence of voids 100 connection structures in Examples and Comparative Examples were prepared. In the obtained connection structure, whether or not voids were generated in the cured product layer formed of the anisotropic conductive paste layer was visually observed from the lower surface side of the transparent glass substrate. The presence or absence of voids was determined according to the following criteria. When there is a void, the conduction reliability in the connection structure is lowered.

[Criteria for the presence or absence of voids]
○○: No void in all 100 connection structures ○: Although there are connection structures with voids having a maximum length of 10 μm or less in 100 connection structures, all connection structures are Usable △: Among 100 connection structures, there are connection structures with voids whose maximum length exceeds 10 μm and 30 μm or less, but all connection structures can be used ×: 100 connection structures There is a connection structure with a maximum length exceeding 30 μm in the body.

(2) Presence / absence of displacement of first and second connection target members 100 connection structures in each of the examples and comparative examples were prepared. In the obtained connection structure, it was evaluated whether or not misalignment occurred between the electrode of the transparent glass substrate and the electrode of the semiconductor chip. The positional deviation was determined according to the following criteria.

[Criteria for misalignment]
○○: There is no displacement between electrodes in all 100 connection structures, or the displacement width between electrodes is 2 μm or less. ○: The displacement width between electrodes exceeds 2 μm in 100 connection structures. All connection structures can be used even though there is a connection structure that is 5 μm or less. Δ: Among 100 connection structures, there is a connection structure in which the displacement width between electrodes exceeds 5 μm and is 10 μm or less. However, all connection structures can be used. X: Among 100 connection structures, there is a connection structure exceeding a displacement width of 10 μm between electrodes.

(3) Presence / absence of contamination Whether or not the anisotropic conductive paste layer adheres to the side surface or upper surface of the semiconductor chip and the pressure heating head (crimping head) during the fabrication of the connection structures in the examples and comparative examples. evaluated. The presence or absence of contamination was determined according to the following criteria.

[Judgment criteria for contamination]
○○: Even when 100 connection structures were manufactured, the anisotropic conductive paste did not adhere to the semiconductor chip and the pressure heating head. ○: When 100 connection structures were manufactured, 1 to 2 Although the anisotropic conductive paste is slightly adhered to the semiconductor chip and the pressure heating head, all the connection structures can be used. Δ: When 100 connection structures are manufactured, 3 to 4 semiconductor chips and Although the anisotropic conductive paste was slightly adhered to the pressure heating head, all the connection structures can be used. X: When 100 connection structures are manufactured, the five semiconductor chips and the pressure heating head can be used. The anisotropic conductive paste is slightly adhered or the anisotropic conductive paste is considerably adhered to one or more semiconductor chips and the pressure heating head.

(4) 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. The case where the average value of the connection resistance was 3Ω or less was judged as “◯”, and the case where the average value of the connection resistance exceeded 3Ω was judged as “X”.

  The results are shown in Table 1 below.

DESCRIPTION OF SYMBOLS 1 ... Connection structure 2 ... 1st connection object member 2a ... Upper surface 2b ... 1st electrode 3 ... Hardened | cured material layer 3a ... Upper surface 3x ... Center part 3y ... Edge part 3A ... Anisotropic conductive paste layer 3B ... B stage Anisotropic conductive paste layer 4 ... second connection target member 4a ... lower surface 4b ... second electrode 5 ... conductive particles 11 ... coating apparatus 12 ... dispenser 12a ... syringe 12b ... gripping part 12c ... tip 13 ... Light irradiation device 13a ... Light irradiation device main body 13b ... Light irradiation unit 14 ... Removal device 14a ... Tip 21 ... Light irradiation device 21a ... Light irradiation device main body 21b ... Light irradiation unit 31 ... Stand R1 ... First region R2 ... Coating amount Second region with a large amount 51A ... Anisotropic conductive paste layer 51a ... Upper surface 51x ... Center part 51y ... Edge part

Claims (14)

An anisotropic conductive paste layer is applied by applying an anisotropic conductive paste containing a thermosetting component and conductive particles from the dispenser while moving the dispenser onto a first connection target member having an electrode on the upper surface. Forming a step;
Removing at least a portion of the anisotropic conductive paste layer with a removing device;
Laminating a second connection target member having an electrode on the lower surface on the anisotropic conductive paste layer;
The anisotropic conductive paste layer is heated to be fully cured to form a cured product layer,
The anisotropic conductive paste layer before being removed by the removing device has a first region and a second region having a larger application amount than the first region, and the first region is A method for manufacturing a connection structure, wherein the removal region is removed by the removal device or the second region having a large coating amount is removed by the removal device.   The method for manufacturing a connection structure according to claim 1, wherein the second region having a large coating amount is removed by the removing device.   The method for manufacturing a connection structure according to claim 1 or 2, wherein a region of the application end portion of the anisotropic conductive paste layer is removed by the removing device.   The manufacturing method of the connection structure of any one of Claims 1-3 whose said 2nd area | region is an area | region of the application | coating end part of the said anisotropic conductive paste layer.   The manufacturing method of the connection structure of any one of Claims 1-4 using the suction removal apparatus which sucks and removes at least one area | region of the said anisotropic conductive paste layer as said removal apparatus.   The manufacturing method of the connection structure of any one of Claims 1-5 using the coating device with which the said dispenser and the said removal apparatus are connected.   The manufacturing method of the connection structure of any one of Claims 1-6 which moves the said dispenser and the said removal apparatus interlock | cooperating.   The outer edge of the central portion of the anisotropic conductive paste layer in the direction orthogonal to the application direction is raised with respect to the central portion of the anisotropic conductive paste layer in the direction orthogonal to the application direction. Thus, the manufacturing method of the connection structure of any one of Claims 1-7 which apply | coats the said anisotropic conductive paste. As the anisotropic conductive paste, using an anisotropic conductive paste containing a thermosetting component, or using an anisotropic conductive paste containing a thermosetting component and a photocurable component,
The anisotropic conductive paste layer further includes a step of forming a B-staged anisotropic conductive paste layer by applying heat or irradiating light to advance curing,
Laminating the second connection target member on the upper surface of the B-staged anisotropic conductive paste layer,
The method for manufacturing a connection structure according to any one of claims 1 to 8, wherein the B-staged anisotropic conductive paste layer is heated and fully cured to form a cured product layer. As the anisotropic conductive paste, using an anisotropic conductive paste containing a thermosetting component and a photocurable component,
Curing proceeds by irradiating the anisotropic conductive paste layer with light to form a B-staged anisotropic conductive paste layer,
The method for manufacturing a connection structure according to claim 9, wherein the B-staged anisotropic conductive paste layer is heated and fully cured to form a cured product layer. A coating apparatus used for coating an anisotropic conductive paste containing a thermosetting component and conductive particles on a first connection target member,
A dispenser for applying the anisotropic conductive paste on the first connection target member;
And a removing device for removing at least a part of the region of the anisotropic conductive paste applied on the first connection target member.   The coating device according to claim 11, wherein the dispenser and the removing device are connected.   The coating device according to claim 11 or 12, wherein the dispenser and the removing device are configured to move in conjunction with each other. Application used for applying an anisotropic conductive paste containing a thermosetting component, a photocurable component, and conductive particles on the first connection target member, and irradiating the anisotropic conductive paste with light. A device,
The coating apparatus of any one of Claims 11-13 further provided with a light irradiation apparatus.

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