JP2013105886A - Method for determining joining condition of electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately determine joining conditions during heating and pressure bonding of electronic components.SOLUTION: A first electronic component 6 and a second electronic component 7 are heated and pressure-bonded to each other with an adhesive film 1 interposed therebetween, which contains a plurality of metal particles 3 different in solidus temperature and particle diameter. Joining conditions during heating and pressure bonding are determined by observing molten states of the metal particles 3 in the adhesive film 1 after heating and pressure bonding.

Description

  The present invention relates to a method for determining bonding conditions for electronic components using an adhesive film containing metal particles.

  Conventionally, a tape-like connection material (for example, anisotropic conductive film (ACF) (hereinafter also referred to as “adhesive film”) in which a curable resin in which conductive particles are dispersed is applied to a release film. ) Is used. This anisotropic conductive film is used, for example, when various terminals are bonded and electrically connected.

  When determining the bonding conditions of the anisotropic conductive film, for example, after setting the temperature and pressure of the heating press device (heating bonder), it is heated (blank), and the temperature reached is measured with a thermocouple. The temperature is estimated, and the anisotropic conductive film is actually pressure-bonded to confirm the melting and bonding state of the conductive particles.

  However, in the measurement of the ultimate temperature with a thermocouple, a deviation from the actual temperature may occur. Further, since there are factors such as pressure, time, heat conduction, heat capacity, etc., it has not been possible to determine whether or not the conductive particles are actually melted and metal-bonded only by the reached temperature. Furthermore, although the presence or absence of a metal bond can be confirmed by press-bonding an anisotropic conductive film containing conductive particles, it has been difficult to determine whether the temperature is excessively applied.

  If the temperature is excessively applied, the thermosetting reaction of the binder proceeds before the binder in the anisotropic conductive film sufficiently flows, and the conductive particles cannot be captured between the terminals of the electronic component. Thereafter, although the conductive particles melt, they are not sufficiently in contact with the terminals of the electronic component, so that a sufficient metal bond cannot be formed. For this reason, the conduction reliability of the connection structure in which the terminals of the electronic components are connected to each other is deteriorated. The temperature is usually measured by inserting a small thermocouple into the measurement part, but it cannot be confirmed with an actual product.

  Therefore, Patent Document 1 discloses a method of blending a heat-sensitive dye capsule in an anisotropic conductive film in order to confirm the bonding conditions (for example, the ultimate temperature and the degree of curing) at the time of pressure bonding of the anisotropic conductive film. Proposed.

  However, since the density of the color changes depending on the thickness, the color becomes dark in the thick anisotropic conductive film, and the color becomes light in the thin anisotropic conductive film. That is, the color changes with a different factor from the arrival of heat. In addition, since the anisotropic conductive film itself is thin, it does not have a sufficient density to be recognized even if it is colored.

JP 2010-129960 A

  This invention is proposed in view of such a situation, and it aims at providing the joining condition determination method of the electronic component which can determine the joining condition at the time of the thermocompression bonding of an electronic component correctly. .

  The method for determining bonding conditions for an electronic component according to the present invention heats the first electronic component and the second electronic component by interposing an adhesive film containing a plurality of metal particles having different solidus temperatures and particle sizes. The bonding conditions at the time of thermocompression bonding are determined by crimping and observing the molten state of the metal particles in the adhesive film after thermocompression bonding.

  In the method for determining bonding conditions for electronic components according to the present invention, the first electronic component and the second electronic component are thermocompression bonded via an adhesive film containing two types of metal particles having different solidus temperatures. The bonding conditions at the time of thermocompression bonding are determined by observing the molten state of the metal particles in the adhesive film after thermocompression bonding.

  The adhesive film according to the present invention contains a plurality of metal particles having different solidus temperatures and particle sizes, and thermocompression-bonds the first electronic component and the second electronic component with the adhesive film interposed therebetween. By observing the molten state of the metal particles in the adhesive film after thermocompression bonding, the bonding conditions during thermocompression bonding are determined.

  The present invention provides a connection structure for connecting a first electronic component and a second electronic component by interposing an adhesive film between the terminal of the first electronic component and the terminal of the second electronic component. In the method, an adhesive film containing a plurality of metal particles having different solidus temperatures and particle sizes is interposed, and the first electronic component and the second electronic component are thermocompression bonded, and in the adhesive film after thermocompression bonding By observing the molten state of the metal particles, the bonding conditions at the time of thermocompression bonding are determined, and based on the bonding conditions, the first electronic component and the second electronic component with the adhesive film interposed are relatively The metal particles having a low solidus temperature are melted and heated and pressed at a heating temperature that does not melt the other metal particles.

  According to the present invention, by observing the molten state of the metal particles in the adhesive film after the thermocompression bonding, it is possible to identify the molten metal particles and the non-molten metal particles. It is possible to accurately determine the conditions, for example, the ultimate temperature during thermocompression bonding.

It is sectional drawing which shows the adhesive film containing two types of metal particles from which solidus temperature and a particle size differ. It is sectional drawing which shows the adhesive film containing three types of metal particles from which solidus temperature and a particle size differ. It is a flowchart for demonstrating an example of the joining condition determination method of the electronic component which concerns on this invention. It is sectional drawing for demonstrating an example of the thermocompression-bonding process in the joining condition determination method of the electronic component which concerns on this invention. It is a flowchart for demonstrating an example of the observation process in the joining condition determination method of the electronic component which concerns on this invention. (A) is 120 degreeC, (B) is a figure which shows the molten state of the metal particle in an adhesive film after carrying out the thermocompression bonding of the electronic component with an adhesive film interposed at 200 degreeC. It is a flowchart for demonstrating an example of the manufacturing method of the connection structure which concerns on this invention.

Hereinafter, embodiments of the present invention (hereinafter referred to as “present embodiments”) will be described in detail in the following order with reference to the drawings.
1. Adhesive film (Fig. 1, Fig. 2)
1-1. Configuration of adhesive film 1-2. 1. Production method of adhesive film Method for determining bonding conditions for electronic components (FIGS. 3 to 6)
3. Manufacturing method of connection structure (FIG. 7)

<1. Adhesive film>
(1-1. Configuration of adhesive film)
The adhesive film according to the present embodiment contains a plurality of metal particles having different solidus temperatures (melting points) and particle sizes. Thus, since the plurality of metal particles in the adhesive film have different particle sizes and solidus temperatures, by observing the molten state of the metal particles in the adhesive film after thermocompression bonding, It is possible to identify unmelted metal particles. For example, the heating temperature under a bonder condition with respect to the adhesive film can be confirmed depending on which particle size of the metal particles is metal-bonded.

  Therefore, as will be described in detail later, by interposing the adhesive film according to the present embodiment, the terminals of the electronic component are thermocompression bonded, and the molten state of the metal particles in the adhesive film after thermocompression bonding is observed. It is possible to accurately and quickly determine the joining conditions during thermocompression bonding, for example, the ultimate temperature during thermocompression bonding. Since such an adhesive film 1 can determine whether the melting and metal bonding conditions and the temperature are excessively applied, in addition to the use of determining the ultimate temperature at the time of thermocompression bonding, it is applied to, for example, a thermosensitive sheet for temperature measurement. be able to.

  As shown in FIG. 1, for example, an anisotropic conductive film can be used as the adhesive film 1. The adhesive film 1 is formed by applying an anisotropic conductive composition 4 in which metal particles 3 (3A, 3B) are dispersed in a binder (adhesive) 2 on a release substrate 5.

  As the binder 2, for example, a material containing a film-forming resin, a thermosetting resin, a latent curing agent, a silane coupling agent, or the like can be used.

  The adhesive film 1 contains a plurality of metal particles 3 having different solidus temperatures and particle sizes. By including a plurality of metal particles 3 having different solidus temperatures and particle sizes in this way, it is possible to identify the molten metal particles 3 and the unmelted metal particles 3 after thermocompression bonding. The temperature reached at the time of thermocompression bonding can be accurately determined.

  As the metal particles 3, it is preferable to prepare a plurality of particles having a solidus temperature close to the target temperature at the time of target thermocompression bonding. For example, it is preferable to use a plurality of metal particles 3 having a difference in solidus line temperature of 1 ° C. or higher with a target solid temperature at the time of thermocompression bonding as the reference, and having a higher solidus line temperature and a smaller particle diameter. In this way, by using a plurality of metal particles 3 having a solidus temperature difference of 1 ° C. or more, the molten metal particles 3 and the unmelted metal particles 3 can be more accurately confirmed, and thus more accurate. The ultimate temperature at the time of thermocompression bonding can be determined. In addition, the kind of metal particle 3 should just be 2 or more types, and in order to confirm the ultimate temperature at the time of thermocompression bonding more reliably, it is preferable to use 3 or more types. For example, as shown in FIG. 2, the adhesive film 1A may contain three types of metal particles 3 (3A, 3B, 3C) having different solidus temperatures and particle sizes.

  The metal particles 3 preferably have a particle size in the vicinity of the particle size of the metal particles 3 in the actually used adhesive film 1A. In addition, as the metal particles 3, it is preferable to use a plurality of particles each having a particle size difference of 1 μm or more. By using the metal particles 3 each having a particle size difference of 1 μm or more, it is possible to easily confirm to what particle size the metal particles 3 have melted by observing the molten state of the metal particles 3 after thermocompression bonding. Therefore, the ultimate temperature at the time of thermocompression bonding can be determined more accurately.

  As the metal particles 3, various conductive particles can be used. For example, particles of various metals such as nickel, iron, copper, aluminum, tin, lead, chromium, cobalt, silver, and gold, particles of metal alloys such as solder, and particles of metal oxide can be used. Moreover, the thing which coat | covered the metal on the surface of particle | grains, such as carbon, a graphite, glass, a ceramic, a plastics, and what further coat | covered the insulating thin film on the surface of these particles can be used. When the metal particles 3 are obtained by coating the surface of the resin particles with metal, examples of the resin particles include epoxy resins, phenol resins, acrylic resins, acrylonitrile / styrene (AS) resins, benzoguanamine resins, and divinylbenzene resins. Particles such as styrene resin can be used.

  Among these metal particles 3, it is preferable to use solder particles. Since the solder particles have a relatively low solidus temperature, they can be thermocompression bonded at a low temperature. In addition, the solidus temperature of the solder particles can be precisely adjusted by combining the composition ratios in various ways. The solder particles can be obtained, for example, by spraying a molten alloy into water from a predetermined nozzle and quenching and solidifying by a normal water atomizing method.

  The peeling substrate 5 is for maintaining the shape of the adhesive film 1A. The release substrate 5 is formed, for example, by applying a release agent such as silicone to PET (Poly Ethylene Terephthalate), OPP (Oriented Polypropylene), PMP (Poly-4-methlpentene-1), PTFE (Polytetrafluoroethylene) or the like.

(1-2. Manufacturing method of adhesive film)
Next, an example of the manufacturing method of the adhesive film 1 described above will be described. For example, after the binder 2 and a plurality of metal particles 3 having different solidus temperatures and particle sizes are mixed in a solvent, the mixture is applied on the release substrate 5 coated with a release agent so as to have a predetermined thickness. And dried to volatilize the solvent. Thereby, the adhesive film 1 containing the some metal particle 3 from which solidus temperature and a particle size differ can be produced.

  The blending amount of the binder 2 and the metal particles 3 is preferably such that the weight parts of each metal particle 3 is about 0.5 to 10 with respect to 100 parts by weight of the binder 2. When the blending amount of the metal particles 3 is less than 0.5 parts by weight, the amount is too small, so that a sufficient metal bond cannot be formed between the terminals. Further, if the blending amount of the metal particles 3 is less than 0.5 parts by weight, it is difficult to determine which particle size of the metal particles 3 is melted because the number of the metal particles 3 is too small. On the other hand, when the compounding amount of the metal particles 3 exceeds 10 parts by weight, electrical coupling (short circuit) may occur between terminals adjacent in the lateral direction. Moreover, when the compounding quantity of the metal particle 3 exceeds 10 weight part, there exists a possibility that the metal particle 3 may fuse | melt and couple | bond together and the particle size of the metal particle 3 may become unknown.

  The metal particles 3 contained in the above-described adhesive film 1 can be used for the purpose of electrically joining the terminals of the electronic components, but for the purpose of temperature indication, that is, the ultimate temperature during thermocompression bonding It may be used only for the purpose of accurately determining.

<2. Method for determining bonding conditions for electronic components>
In performing the electronic component joining condition determination method according to the present embodiment, heating is performed after setting the temperature and pressure of the heating and pressing device, and at that time, the temperature reached is estimated by measuring with a thermocouple. Keep it. Thereafter, the adhesive film 1 is actually pressure-bonded, and the molten and bonded state of the metal particles 3 is confirmed.

  In the electronic component joining condition determination method according to the present embodiment, the first electronic component and the second electronic component are thermocompression bonded with the adhesive film 1 interposed therebetween, and the metal in the adhesive film 1 after thermocompression bonding. By observing the molten state of the particles 3, the bonding conditions during thermocompression bonding are determined. Thereby, for example, it is possible to measure the temperature reached at the time of thermocompression bonding more accurately than the measurement of the pressure bonding temperature by a conventional thermocouple. Moreover, a finer temperature range can be specified as compared with the case where an adhesive film containing only one kind of metal particles 3 is used. As a result, the ultimate temperature at the time of thermocompression bonding can be determined accurately and quickly.

  As shown in FIG. 3, for example, the electronic component joining condition determination method according to the present embodiment includes an adhesive film manufacturing step S1, a thermocompression bonding step S2, and an observation step S3.

  In the adhesive film production step S1, the adhesive film 1 is produced by, for example, the method for producing the adhesive film 1 described above.

  In the thermocompression bonding step S2, for example, as shown in FIG. 4, the first electronic component 6 and the second electronic component 7 are thermocompression bonded with the adhesive film 1 interposed.

  Examples of the first electronic component 6 and the second electronic component 7 include semiconductor chips other than IC chips such as IC chips and LSI (Large Scale Integration) chips, semiconductor elements such as chip capacitors, flexible printed boards, and rigid boards. Etc.

  The thermocompression bonding of the first electronic component 6 and the second electronic component 7 can be performed using, for example, a heat pressing device. For example, thermocompression bonding sets the conditions of the heating and pressing device, such as temperature, pressure, and time, and cures the thermosetting resin in the adhesive film 1 while pressing the upper surface of the electronic component with the heating and pressing device at a predetermined pressure. It is performed by heating at a temperature higher than the temperature. Although the heating temperature at the time of thermocompression bonding varies depending on the type of thermosetting resin, for example, the temperature may be about 140 to 230 ° C. The pressure at the time of thermocompression bonding may be about 2 to 50 MPa, for example. The time for thermocompression bonding is preferably 5 to 30 seconds, for example. Preventing the fluidity of the anisotropic conductive composition 4 from becoming insufficient and preventing the workability from deteriorating by setting the time for thermocompression bonding to 5 to 30 seconds. Can do.

  In the observation step S3, the part that has been heat-bonded is peeled off, and the molten metal particles 3 in the adhesive film 1 after the heat-bonding are observed to confirm the molten metal particles 3 and the molten metal particles 3. .

  For example, as shown in FIG. 5, in the observation step S <b> 3, first, it is confirmed whether there are unmelted metal particles 3 (step S <b> 10). For example, the heat-pressed adhesive film 1 is peeled off by hand, and the particle size of the metal particles 3 in the adhesive film 1 is visually observed using an optical microscope. Check if it is.

  An example of the molten state of the metal particles 3 after the first electronic component 6 and the second electronic component 7 are thermocompression bonded with the adhesive film 1 interposed therebetween is shown in FIG. In the example shown in FIG. 6, as the metal particles 3, solder particles having an average particle diameter of 10 μm and a solidus temperature of 140 to 200 ° C. (solid-liquid phase line width that starts melting from 140 ° C. and completely melts at 200 ° C. Wide solder particles). The temperature for thermocompression bonding was 120 ° C. (solidus temperature or lower) and 200 ° C. (solidus temperature or higher).

  When thermocompression bonding is performed at a temperature below the solidus temperature, the metal particles 3 are somewhat crushed as shown in FIG. 6A, so that the particle size of the metal particles 3 is slightly larger than before the thermocompression bonding. On the other hand, when thermocompression bonding is performed at a temperature equal to or higher than the solidus temperature, as shown in FIG. 6B, the particle size of the metal particles 3 is clearly larger than that before thermocompression bonding. Thus, by observing the particle size of the metal particles 3 in the adhesive film 1 after thermocompression bonding, it can be confirmed whether or not the metal particles 3 are melted. In the example shown in FIG. 6A, the first electronic component 6 or the second electronic component 7 is peeled off at the interface between the cured adhesive film 1 layer (interface failure). In the example shown in FIG. 6B, the layer of the cured adhesive film 1 is peeled off by being broken (cohesive failure).

  In step S10, when there are unmelted metal particles 3, the process proceeds to step S11, and when there are no unmelted metal particles 3, the process proceeds to step S12.

  In step S11, the particle size of the unmelted metal particles 3 is observed. Thereby, it is possible to specify that the ultimate temperature at the time of thermocompression bonding is lower than the solidus temperature of the molten metal particles 3 and is equal to or higher than the solidus temperature of the molten metal particles 3.

  If there is no unmelted metal particle 3 in step S12, the temperature reached at the time of thermocompression bonding is excessive, so the process returns to the adhesive film production step S1.

  In the electronic component joining condition determination method according to the present embodiment, the first electronic component 6 and the second electronic component 6 are interposed by interposing an adhesive film 1 containing a plurality of metal particles 3 having different solidus temperatures and particle sizes. The electronic component 7 is thermocompression bonded, and the particle size of the metal particles 3 in the adhesive film 1 after thermocompression bonding is observed.

  As a result of observing the particle size of the metal particle 3, as described above, when the particle size of the metal particle 3 is slightly larger than that before the thermocompression bonding, it is specified that the metal particle 3 is not melted. be able to. On the other hand, when the particle size of the metal particle 3 is clearly larger than that before the thermocompression bonding, it can be specified that the metal particle 3 is melted. Thus, by observing the molten state of the metal particles 3 in the adhesive film 1 after thermocompression bonding, the molten metal particles 3 and the unmelted metal particles 3 can be specified. Can be accurately determined.

  In the above description, in the observation step S3, the molten state of the metal particles 3 is visually observed using an optical microscope. However, the present invention is not limited to this. For example, when observing the particle size of the metal particle 3 using an optical microscope, the area value of the metal particle 3 is calculated by image processing to identify the molten metal particle 3 and the unmelted metal particle 3. And the ultimate temperature at the time of thermocompression bonding may be determined.

  For example, as the metal particles 3, the above-described solder particles having an average particle diameter of 10 μm and a solidus temperature of 140 to 200 ° C. are used, and the temperature at the time of thermocompression bonding is 120 ° C. (below the solidus temperature) and 200 ° C. Table 1 shows the results of the area values of the metal particles 3 after thermocompression bonding in the case of (above the solidus temperature).

As shown in Table 1, the average of the area location in the case of heat pressing in the solidus temperature less (630.4393μm ^2), the average of the area location in the case of thermocompression bonding at the solidus temperature or more (1143.96μm ² ) And there is a difference of about twice. Therefore, by calculating the area value of the metal particles 3 after thermocompression bonding by image processing, it is possible to identify the molten metal particles 3 and the unmelted metal particles 3 and determine the ultimate temperature during thermocompression bonding. it can.

  In the above description, the adhesive film 1 containing a plurality of metal particles 3 having different solidus temperatures and particle sizes is used. However, the present invention is not limited to this example. For example, only the solidus temperature is different. An adhesive film containing two types of metal particles may be used. Even when the first electronic component 6 and the second electronic component 7 are thermocompression-bonded by interposing an adhesive film containing two types of metal particles having only different solidus temperatures as described above, The molten state of the metal particles in the adhesive film is observed. Thereby, since the melted metal particle and the metal particle which is not melt | dissolved can be specified, the ultimate temperature at the time of thermocompression bonding can be determined correctly.

  Further, in the above description, the optimum ultimate temperature when the pressure and the thermocompression bonding time are fixed is determined as the joining condition during thermocompression bonding, but the present invention is not limited to this example. For example, as a bonding condition at the time of thermocompression bonding, an optimal thermocompression bonding time when the ultimate temperature and pressure are constant, and an optimal pressure when the ultimate temperature and thermocompression bonding time are constant may be determined. .

<3. Manufacturing method of connection structure>
Next, a method for manufacturing a connection structure to which the above-described electronic component joining condition determination method is applied will be described. In the manufacturing method of the connection structure according to the present embodiment, the adhesive film 1 is interposed between the terminal of the first electronic component 6 and the terminal of the second electronic component 7, and the first electronic component 6 and The second electronic component 7 is connected. The first electronic component 6 and the second electronic component 7 are thermocompression bonded with the adhesive film 1 containing a plurality of metal particles 3 having different solidus temperatures and particle sizes, and the adhesive film after thermocompression bonding The molten state of the metal particles in 1 is observed. Thereby, the ultimate temperature at the time of thermocompression bonding that melts the metal particles 3 having a relatively low solidus temperature and does not melt the other metal particles 3 is determined. Subsequently, based on the determined reached temperature, the first electronic component 6 and the second electronic component 7 with the adhesive film 1 interposed therebetween are melted with the metal particles 3 having a relatively low solidus temperature, Heating and pressing are performed at a temperature (tool temperature) of a heating and pressing device that does not melt the other metal particles 3.

  The manufacturing method of the connection structure according to the present embodiment includes, for example, as shown in FIG. 7, an adhesive film production step S20, a thermocompression bonding step S21, an observation step S22, and a main pressure bonding step S23. The adhesive film production step S20, the thermocompression bonding step S21 and the observation step S22 are the same as the adhesive film production step S1, the thermocompression bonding step S2 and the observation step S3 in the electronic component joining condition determination method described above, and a detailed description thereof will be given. Omitted. In this connection structure manufacturing method, it is preferable to use the metal particles 3 having a smaller particle diameter as the solidus temperature is higher as described above.

  In the main compression bonding step S23, the first electronic component 6 and the second electronic component 7 with the adhesive film 1 interposed are relatively solid-phased based on the molten state of the metal particles 3 observed in the observation step S22. The metal particles 3 having a low line temperature are melted and heated and pressed at a heating temperature at which the other metal particles 3 are not melted.

  In the connection structure obtained by such a manufacturing method of the connection structure, the molten metal particles 3 are metal-bonded. Usually, the metal particles 3 melted by heating and pressurizing are crushed and spread, and there is a risk that the lateral terminals are short-circuited by the metal particles 3, but the metal particles 3 that are not melted, that is, relatively solid phase lines. A short circuit can be prevented by controlling the thickness of the metal particles 3 when the molten metal particles 3 are crushed by the metal particles 3 having a high temperature.

  Further, when the production amount of the connection structure is small, for example, an anisotropic conductive film for determining bonding conditions can also be used as an anisotropic conductive film for actual connection. Therefore, the connection according to the present embodiment The manufacturing method of the structure is advantageous in terms of cost.

  In the main crimping step S23, if necessary, the conditions of the heating and pressing device are changed based on the temperature reached in the observation step S22, and the heating of the first electronic component 6 and the second electronic component 7 is performed again. Crimping may be performed.

  Examples of the present invention will be described below. The present invention is not limited to these examples. In the following examples, an anisotropic conductive film containing a plurality of solder particles having different solidus temperatures and particle sizes in Production Example 1 to Production Example 5 is produced, and an electronic component is produced using this anisotropic conductive film. The joining conditions were determined.

<Preparation of anisotropic conductive film>
(Preparation of solder particles)
By a normal water atomization method, the molten alloy was sprayed into water from a predetermined nozzle and rapidly solidified to obtain the following five types of solder particles (1) to (5).
(1) Solder particles (a)
Sn: 91 parts by weight, Zn: 9 parts by weight (solidus temperature 198 ° C., particle size 16 μm)
(2) Solder particles (b)
Sn: 95.8 parts by weight, Ag: 3.5 parts by weight, Cu: 0.7 parts by weight (solidus temperature 217 ° C., particle size 14 μm)
(3) Solder particles (c)
Sn: 96.5 parts by weight, Ag: 3.5 parts by weight (solidus temperature 221 ° C., particle size 12 μm)
(4) Solder particles (d)
Sn: 49 parts by weight, In: 34 parts by weight, Pb: 17 parts by weight (solidus temperature 130 ° C., particle size 12 μm)
(5) Solder particles (e)
Sn: 47 parts by weight, Bi: 53 parts by weight (solidus temperature 138 ° C., particle size 10 μm)

(Preparation of anisotropic conductive film)
As shown in the following Production Examples 1 to 5, 100 parts by weight of the base compounding resin and a predetermined number of solder particles are dissolved in 100 parts by weight of toluene, mixed, and then applied onto a peeled PET sheet using a bar coater. The solvent was volatilized by drying at 60 ° C. for 10 minutes to obtain an anisotropic conductive film having a thickness of 30 μm. As the base compounding resin (binder), 40 parts by weight of an imidazole-based curing agent (manufactured by Asahi Ciba, HX-3941HP), 40 parts by weight of phenoxy resin (PKHH), and bisphenol A type epoxy resin (ep828, manufactured by Japan Epoxy Resin Co., Ltd.) ) 20 parts by weight were used.

  In Production Example 1, an anisotropic conductive film in which 100 parts by weight of a base compounded resin, 3 parts by weight of solder particles (a), 3 parts by weight of solder particles (b), and 3 parts by weight of solder particles (c) are blended Got.

  In Production Example 2, an anisotropic conductive film in which 100 parts by weight of the base compounding resin, 3 parts by weight of the solder particles (d), and 3 parts by weight of the solder particles (e) were obtained was obtained.

  In Production Example 3, an anisotropic conductive film in which 100 parts by weight of the base compounding resin and 3 parts by weight of the solder particles (a) were blended was obtained.

  In Production Example 4, an anisotropic conductive film in which 100 parts by weight of the base compounding resin and 3 parts by weight of the solder particles (b) were blended was obtained.

  In Production Example 5, an anisotropic conductive film in which 100 parts by weight of the base compounding resin and 3 parts by weight of the solder particles (d) were blended was obtained.

  In Production Example 6, an anisotropic conductive film in which 100 parts by weight of the base compounding resin and 3 parts by weight of the solder particles (e) were blended was obtained.

<Example 1>
In Example 1, using the anisotropic conductive film obtained in Production Example 1, the optimum temperature (tool temperature) of the heating and pressing device that metal-bonds only the solder particles (a) was determined.

(Measurement 1)
Using the anisotropic conductive film obtained in Production Example 1, a flexible printed board for conductive reliability evaluation with a 200 μm pitch (L / S = 100 μm / 100 μm, gold plating treatment) and a terminal part of a rigid board were connected. . Using a heat press bonder (manufactured by Sony Chemical & Information Device Co., Ltd.), heat press was performed at 400 ° C. and 3 MPa for 10 seconds, and then the pressure was released to obtain a connection structure. The adhesive part of the obtained connection structure was peeled off by hand, and the molten state of the solder particles in the anisotropic conductive film after thermocompression bonding was observed. By observing the particle size of unmelted solder particles in the anisotropic conductive film, the melted solder particles were identified, and the temperature reached during thermocompression bonding was confirmed. The melting state of the solder particles was visually confirmed using an optical microscope for the melting of the solder particles and the presence or absence of metal bonding.

  The solder particles (a) were melted, the solder particles (b) were not melted, and the solder particles (c) were not melted. From this result, the ultimate temperature at the time of thermocompression bonding in Measurement 1 was 198 ° C. or higher and less than 217 ° C., and it was confirmed that the ultimate temperature at the thermocompression bonding was appropriate.

(Measurement 2)
A connection structure was obtained in the same manner as in Measurement 1 except that a heat press bonder was used for 10 seconds at 430 ° C. and 3 MPa. About the obtained connection structure, it carried out similarly to the measurement 1, and observed the molten state of the solder particle in the anisotropic conductive film after thermocompression bonding. The solder particles (a) were melted, the solder particles (b) were melted, and the solder particles (c) were not melted. From this result, the ultimate temperature at the time of thermocompression bonding in Measurement 2 was 217 ° C. or more and less than 221 ° C., and it was confirmed that the ultimate temperature at the thermocompression bonding was excessive.

<Example 2>
In Example 2, using the anisotropic conductive film obtained in Production Example 2, the optimum temperature (tool temperature) of the heating and pressing device that metal-bonds only the solder particles (d) was determined.

(Measurement 3)
Using the anisotropic conductive film obtained in Production Example 2, the flexible printed circuit board and the terminal part of the rigid circuit board were connected. Using a heat press bonder (manufactured by Sony Chemical & Information Device Co., Ltd.), heat press was performed at 300 ° C. and 3 MPa for 10 seconds, and then the pressure was released to obtain a connection structure. About the obtained connection structure, it carried out similarly to the measurement 1, and observed the molten state of the solder particle in the anisotropic conductive film after thermocompression bonding. The solder particles (d) were melted, and the solder particles (e) were not melted. From this result, the ultimate temperature at the time of thermocompression bonding in Measurement 3 was 130 ° C. or higher and less than 138 ° C., and it was confirmed that the ultimate temperature at the thermocompression bonding was appropriate.

(Measurement 4)
A connection structure was obtained in the same manner as in Measurement 3, except that the heat pressing was performed at 330 ° C. and 3 MPa for 10 seconds using a heat pressing bonder. About the obtained connection structure, it carried out similarly to the measurement 1, and observed the molten state of the solder particle in the anisotropic conductive film after thermocompression bonding. The solder particles (d) were melted and the solder particles (e) were melted. From this result, it was confirmed that the ultimate temperature during thermocompression bonding in Measurement 4 was 138 ° C. or higher, and that the ultimate temperature during thermocompression bonding was excessive.

<Comparative Example 1>
(Measurement 5)
Using the anisotropic conductive film obtained in Production Example 3, the flexible printed circuit board and the terminal part of the rigid circuit board were connected. Using a heat press bonder (manufactured by Sony Chemical & Information Device Co., Ltd.), heat press was performed at 400 ° C. and 3 MPa for 10 seconds, and then the pressure was released to obtain a connection structure. About the obtained connection structure, it carried out similarly to the measurement 1, and observed the molten state of the solder particle in the anisotropic conductive film after thermocompression bonding. Solder particles (a) were melted. From this result, it was confirmed that the ultimate temperature at the time of thermocompression bonding in Measurement 5 was 198 ° C. or higher. However, it has not been possible to confirm whether the ultimate temperature during thermocompression bonding is appropriate or excessive.

(Measurement 6)
A connection structure was obtained in the same manner as in Measurement 5, except that the heating and pressing were performed at 430 ° C. and 3 MPa for 10 seconds using a heating and pressing bonder. About the obtained connection structure, it carried out similarly to the measurement 1, and observed the molten state of the solder particle in the anisotropic conductive film after thermocompression bonding. The solder particles (d) were melted and the solder particles (e) were melted. From this result, it was confirmed that the ultimate temperature during thermocompression bonding in Measurement 6 was 198 ° C. or higher. However, it has not been possible to confirm whether the ultimate temperature during thermocompression bonding is appropriate or excessive.

(Measurement 7)
Using the anisotropic conductive film obtained in Production Example 4, the flexible printed circuit board and the terminal part of the rigid circuit board were connected. A heat press bonder (manufactured by Sony Chemical & Information Device Co., Ltd.) was used for 10 seconds at 430 ° C. and 3 MPa, and then the pressure was released to obtain a connection structure. About the obtained connection structure, it carried out similarly to the measurement 1, and observed the molten state of the solder particle in the anisotropic conductive film after thermocompression bonding. Solder particles (b) were melted. From this result, it was confirmed that the ultimate temperature during thermocompression bonding in Measurement 7 was 217 ° C. or higher. However, it has not been possible to confirm whether the ultimate temperature during thermocompression bonding is appropriate or excessive.

<Comparative example 2>
(Measurement 8)
Using the anisotropic conductive film obtained in Production Example 5, the flexible printed circuit board and the terminal part of the rigid circuit board were connected. Using a heat press bonder (manufactured by Sony Chemical & Information Device Co., Ltd.), heat press was performed at 300 ° C. and 3 MPa for 10 seconds, and then the pressure was released to obtain a connection structure. About the obtained connection structure, it carried out similarly to the measurement 1, and observed the molten state of the solder particle in the anisotropic conductive film after thermocompression bonding. The solder particles (d) were melted. From this result, it was confirmed that the ultimate temperature during thermocompression bonding in Measurement 8 was 130 ° C. or higher. However, it has not been possible to confirm whether the ultimate temperature during thermocompression bonding is appropriate or excessive.

(Measurement 9)
A connection structure was obtained in the same manner as in measurement 8, except that the heat pressing was performed at 330 ° C. and 3 MPa for 10 seconds using a heat pressing bonder. About the obtained connection structure, it carried out similarly to the measurement 1, and observed the molten state of the solder particle in the anisotropic conductive film after thermocompression bonding. The solder particles (d) were melted. From this result, it was confirmed that the ultimate temperature during thermocompression bonding in Measurement 9 was 130 ° C. or higher. However, it has not been possible to confirm whether the ultimate temperature during thermocompression bonding is appropriate or excessive.

(Measurement 10)
Using the anisotropic conductive film obtained in Production Example 6, the flexible printed circuit board and the terminal part of the rigid circuit board were connected. Using a heat press bonder (manufactured by Sony Chemical & Information Device Co., Ltd.), heat press was performed at 330 ° C. and 3 MPa for 10 seconds, and then the pressure was released to obtain a connection structure. About the obtained connection structure, it carried out similarly to the measurement 1, and observed the molten state of the solder particle in the anisotropic conductive film after thermocompression bonding. Solder particles (e) were melted. From this result, it was confirmed that the ultimate temperature during thermocompression bonding in Measurement 10 was 138 ° C. or higher. However, it has not been possible to confirm whether the ultimate temperature during thermocompression bonding is appropriate or excessive.

  Table 2 summarizes the results of the electronic component joining condition determination method in Example 1, Example 2, Comparative Example 1 and Comparative Example 2.

  Moreover, the connection evaluation of the connection structure obtained in the measurement 1 to the measurement 10 was performed. In connection evaluation, the connection structure obtained in measurement 1 to measurement 10 was put into an environmental test of TCT (temperature cycle test) 500 cycles of 60 ° C., 90% RH, 500 hr, and −40 ° C. to 85 ° C. Later conduction reliability was evaluated. None of the connection structures obtained in Measurements 4 to 10 had good conduction reliability. This is because the thermosetting reaction of the binder proceeds before the binder in the anisotropic conductive film sufficiently flows due to excessive application of temperature, and the conductive particles can be captured between the terminals. This is probably because a sufficient metal bond could not be formed by the solder particles.

  As described above, in this example, the anisotropic conductive film containing a plurality of solder particles having different solidus temperature and particle size is interposed, the terminals are thermocompression bonded, and the anisotropic after thermocompression bonding The melting state of the solder particles in the conductive film was observed. By observing the melting state of the solder particles in the anisotropic conductive film after thermocompression bonding, it is possible to identify the molten solder particles and the unmelted solder particles, and whether or not the temperature is excessively applied. I was able to judge. Therefore, in the present invention, it has been found that the ultimate temperature at the time of thermocompression bonding can be determined accurately.

  DESCRIPTION OF SYMBOLS 1 Adhesive film, 2 Binder, 3 Metal particle, 4 Anisotropic electrically conductive composition, 5 peeling base material, 6 1st electronic component, 7 2nd electronic component

Claims (10)

  The first electronic component and the second electronic component are thermocompression bonded via an adhesive film containing a plurality of metal particles having different solidus temperatures and particle sizes, and the metal particles in the adhesive film after thermocompression bonding A bonding condition determination method for an electronic component that determines a bonding condition at the time of thermocompression bonding by observing the molten state.   The joining of electronic components according to claim 1, wherein an ultimate temperature is determined as a joining condition during the thermocompression bonding by observing a particle size of the metal particles in the adhesive film after the thermocompression bonding as the molten state of the metal particles. Condition determination method.   The method for determining bonding conditions for an electronic component according to claim 2, wherein the metal particles have a smaller particle size as the solidus temperature increases.   The method for determining bonding conditions for an electronic component according to claim 3, wherein the metal particles have a solidus temperature difference of 1 ° C. or more.   The method for determining bonding conditions for an electronic component according to claim 4, wherein the metal particles have a particle size difference of 1 μm or more.   The method for determining bonding conditions for an electronic component according to any one of claims 2 to 5, wherein the metal particles are solder particles.   The method for determining bonding conditions for an electronic component according to claim 2, wherein the adhesive film is an anisotropic conductive film.   The first electronic component and the second electronic component are thermocompression bonded via an adhesive film containing two types of metal particles having different solidus temperatures, and the metal particles in the adhesive film after thermocompression are melted. An electronic component joining condition determination method for determining a joining condition at the time of thermocompression bonding by observing a state. Contains a plurality of metal particles with different solidus temperatures and particle sizes,
By bonding the first electronic component and the second electronic component by interposing the adhesive film, and observing the molten state of the metal particles in the adhesive film after the thermocompression bonding, bonding at the time of thermocompression bonding Adhesive film for determining conditions. In a method for manufacturing a connection structure in which an adhesive film is interposed between a terminal of a first electronic component and a terminal of a second electronic component to connect the first electronic component and the second electronic component. ,
The first electronic component and the second electronic component are thermocompression bonded with the adhesive film containing a plurality of metal particles having different solidus temperatures and particle sizes, and the metal in the adhesive film after thermocompression bonding By observing the melting state of the particles, determine the bonding conditions during thermocompression bonding,
Based on the bonding conditions, the first electronic component and the second electronic component having the adhesive film interposed therebetween are melted with metal particles having a relatively low solidus temperature, and other metal particles are A method for manufacturing a connection structure, in which heating and pressing are performed at a heating temperature that does not cause melting.

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