JP2009099708A - Connecting method for terminal, bonding structure for terminal, and resin for connection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connecting method for connection terminals in which the connection terminals can be electrically connected to each other using capacity coupling. <P>SOLUTION: The connecting method includes the stages of: coating a first connection terminal 11 with a resin 3 for connection; connecting the first connection terminal 11 to a second connection terminal through the resin 3 for connection; and solidifying the resin 3 for connection. In the resin 3 for connection having been solidified, some of a plurality of first conductive powder 32 are dispersed apart from one another, and some of a plurality of second conductive powders 33 come in contact with each other to connect the first connection terminal 11 and second connection terminal 21 to each other. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a terminal connection method, a terminal bonding structure, and a connection resin.

  In conventional electronic components, most of the electrical connections between terminals use solder or a conductive adhesive. In the conductive adhesive, a plurality of conductive powders are mixed in an insulating resin, and these conductive powders contact each other to ensure electrical connection between terminals.

  Connection between terminals by solder or conductive adhesive ensures electrical continuity only by the physical contact between the conductive materials. In such a case, when stress is applied to the connection portion, physical contact is lost, and as a result, there is a possibility that conduction cannot be ensured. In the case where the connection terminals can be electrically connected using capacitive coupling, conduction can be ensured without physical contact, and thus the above-described problems can be suppressed.

  The present invention has been made in view of the above circumstances, and its purpose is to provide a terminal connection method capable of electrically connecting connection terminals using capacitive coupling, a terminal joining structure, and It is to provide a resin for connection.

In order to solve the above problems, a terminal connection method according to the present invention includes an insulating resin, a plurality of first conductive powders mixed in the resin and having an average particle size of 5 nm to 500 nm, A step of applying a connection resin having a plurality of second conductive powders mixed in the resin and having an average particle diameter of 500 nm to 20 μm on the first connection terminals;
Connecting the first connection terminal and the second connection terminal via the connection resin;
Solidifying the connecting resin;
Comprising
In the connection resin after solidification, at least some of the plurality of first conductive powders are dispersed in the connection resin in a state of being separated from each other, and the plurality of second conductive powders Some connect the first connection terminal and the second connection terminal by contacting each other.

Another terminal connection method according to the present invention includes an insulating resin having flexibility in a solidified state, and a plurality of first conductive powders mixed in the resin and having an average particle diameter of 5 nm to 500 nm. And applying a connecting resin having a plurality of second conductive powders mixed in the resin and having an average particle diameter of 500 nm or more and 20 μm or less to the first connection terminals;
Solidifying the connecting resin;
Connecting the first connection terminal and the second connection terminal via the connection resin;
Comprising
In the connection resin after solidification, at least some of the plurality of first conductive powders are dispersed in the connection resin in a state of being separated from each other, and the plurality of second conductive powders Some connect the first connection terminal and the second connection terminal by contacting each other.

  The insulating paste is preferably applied to one surface of the first connection terminal.

The junction structure of the terminal according to the present invention includes a first connection terminal,
A second connection terminal;
Insulating resin, a plurality of first conductive powders mixed in the resin and having an average particle diameter of 5 nm to 500 nm, and a plurality of first conductive powders mixed in the resin and having an average particle diameter of 500 nm to 20 μm A second conductive powder, and a connection resin for connecting the first connection terminal and the second connection terminal;
Comprising
At least a part of the plurality of first conductive powders are dispersed in the connecting resin in a state of being separated from each other, and a part of the plurality of second conductive powders is brought into contact with each other, thereby A junction structure of a terminal connecting the first connection terminal and the second connection terminal.

  The connecting resin may have flexibility. In this case, it can be made removable from at least one of the first connection terminal and the second connection terminal.

  The plurality of first conductive powders transmit an AC component of a signal between the first connection terminal and the second connection terminal, and the plurality of second conductive powders transmit a DC component of the signal. Transmission is performed between the first connection terminal and the second connection terminal.

The mixing amount of the plurality of second conductive powders with respect to the plurality of first conductive powders is preferably 2 to 20 times by weight. The connecting resin preferably has a relative dielectric constant of 1000 or more, and more preferably has a relative permeability of 10 or more.
The connecting resin preferably has a thickness of 500 nm to 50 μm.

The connecting resin according to the present invention includes an insulating resin,
A plurality of first conductive powders mixed in the resin and having an average particle size of 5 nm or more and 500 nm or less;
A plurality of second conductive powders mixed in the resin and having an average particle size of 500 nm to 20 μm.

  According to the present invention, the first connection terminal and the second connection terminal can be electrically connected using capacitive coupling.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view for explaining a joint structure between a substrate 1 and an electronic component 2 according to an embodiment of the present invention, and FIG. 2 is an enlarged view of a main part of FIG. In the present embodiment, the connection terminal 21 of the electronic component 2 is connected to the connection terminal 11 of the substrate 1 through the connection resin 3. The electronic component 2 is an LSI package such as a Bump Grid Array. The thickness of the connecting resin 3 in the solidified state is, for example, not less than 500 nm and not more than 50 μm.

  The connection resin 3 is obtained by mixing a plurality of first conductive powders 32 and second conductive powders 33 in an insulating resin 31 serving as a base material. The resin 31 is solidified by vaporizing the solvent or by polymerization or condensation.

  The resin 31 may have flexibility in a solidified state. In this case, the connection resin 3 can be bonded to the connection terminals 11 and 21 by the van der Waals force between the resin 31 and the connection terminals 11 and 21, respectively. The resin 31 is, for example, an organic material, but is desirably a rubber or gel-like material, and is preferably a silicone gel or rubber. The resin 31 is preferably a rubber or gel that is not mixed with monomers, primers, and low molecules in order to withstand vacuum processing. In addition, when the resin 31 is other than silicone, an —O— or —S— group having a conformable molecular skeleton is appropriately introduced. When the resin 31 sufficiently follows the surfaces of the connection terminals 11 and 21, the resin 31 has sufficient adhesive force even with van der Waals force. Therefore, the side chain of the rubber or gel as the resin 31 may be an alkyl group, but when the contact area due to the unevenness of the electrical connection intervening sheet is insufficient and the adhesive force is insufficient, an appropriate polarization group for the side chain For example, it is preferable to introduce an amine group, amino group, carboxyl group, hydroxyl group or the like. When removing an electronic component in the middle of the process, the adhesive force is controlled so that it can be removed. In this case, the contact area is increased by applying pressure after completion to ensure stability. However, even after this, since the joining is mainly made of van der Waals, it can be removed basically.

  The first conductive powder 32 is, for example, a metal powder such as silver, or a composite powder in which a metal core is covered with an insulating film, and the insulating film is further covered with a conductive film, and the average particle size is 5 nm or more. Although it is 500 nm or less, 5 nm or more and 100 nm or less may be sufficient. The mixing amount of the first conductive powder 32 is, for example, 0.05 times or more and 0.5 times or less in a weight ratio with respect to the resin 31. In the state where the resin 31 is solidified, at least a part, for example, 50% or more of the first conductive powder 32 is dispersed at an interval of 5 nm to 500 nm. The remaining first conductive powder 32 is partially agglomerated. Further, a part of the remaining first conductive powder 32 connects the connection terminals 11 and 21 by contacting each other. The first conductive powder 32 is preferably granular (preferably spherical), but may be flaky.

  The second conductive powder 33 is, for example, a metal powder such as silver, and the average particle diameter is 500 nm or more and 20 μm or less. Part of the second conductive powder 33 is connected to the connection terminals 11 and 21 by being in contact with each other. The second conductive powder 33 may be flaky or granular. Although the first conductive powder 32 is relatively expensive with respect to the second conductive powder 33, the amount of the plurality of second conductive powders 33 mixed in the first conductive powder 32 is When the weight ratio is 2 times or more and 20 times or less, the mixing amount of the first conductive powder 32 can be suppressed, and as a result, cost effectiveness can be increased.

  In such a configuration, the connection terminals 11 and 21 are electrically connected to each other by capacitive coupling by the first conductive powder 32, and the second conductive powder 33 is physically connected in parallel with the capacitive coupling. Electrical connection by simple contact. When a pulse signal is input between the connection terminals 11 and 21, the AC component of the pulse signal propagates between the connection terminals 11 and 21 mainly by capacitive coupling by the first conductive powder 32. The direct current component of the pulse signal propagates between the connection terminals 11 and 21 by physical contact of the second conductive powder 33. The frequency of the pulse signal may be any value within a range from a low frequency (for example, 1 MHz) to a high frequency (for example, 3 GHz).

  The relative dielectric constant of the connecting resin 3 is 1000 or more for the reason described later, and the relative permeability is 10 or more. For this reason, the resistance value due to the capacitive coupling described above is sufficiently small. For example, when the connection terminals 11 and 21 are 80 μmφ and the thickness of the connection resin 3 in the solidified state is 50 μm, the contact resistance between the connection terminals 11 and 21 and the connection resin 3 is several mΩ to several tens of Ω. However, the connection capacitance can be achieved from 5 pF to several tens of pF, which is a value that is sufficiently practical for connection of a normal electronic device. In particular, when the frequency of the pulse signal is 1 GHz or higher, connection transmission characteristics better than solder connection can be obtained.

  Next, a first example of a method for manufacturing the above-described terminal bonding structure will be described. In this example, the resin 31 of the connecting resin 3 may have flexibility in a solidified state or may not have flexibility. First, the connecting resin 3 before solidification is prepared. Next, the connection resin 3 is applied to one surface of either the connection terminal 11 or the connection terminal 21. Next, the connection terminal 11 and the connection terminal 21 are connected via the connection resin 3, and then the solvent for the resin 31 is vaporized, or the resin 31 is polymerized or condensed to solidify the connection resin 3. In this case, the connection resin 31 and the connection terminals 11 and 21 are connected by the adhesive force of the resin 31.

  Next, a second example of the manufacturing method of the terminal junction structure described above will be described. In this example, the resin 31 of the connection resin 3 has flexibility in a solidified state, and the connection resin 31 and the connection terminals 11 and 21 are connected by van der Waals force. First, the connecting resin 3 before solidification is prepared. Next, the connection resin 3 is applied to one surface of either the connection terminal 11 or the connection terminal 21. Next, the connection resin 3 is solidified by evaporating the solvent of the resin 31 or polymerizing or condensing the resin 31. Thereafter, the connection terminal 11 and the connection terminal 21 are pressed against each other via the connection resin 3 to be connected to each other. In the case of this example, the connection terminals 11 and 21 can be made detachable from the connection resin 3 as shown in FIG. By controlling the adhesiveness of the connecting resin 3 in the solidified state, the connecting resin 3 can be used as a semi-permanent permanent adhesive connecting sheet or a replaceable joining sheet.

  Next, the reason why the relative dielectric constant and relative permeability of the connecting resin 3 are high will be described. Free electrons in a metal can behave like plasma, but the perturbation is quantized and called plasmon, and the electron spin perturbation is called magnon. Although the perturbation is homogenized in the metal, it reacts to electromagnetic waves, and dielectric constant and permeability appear. The dielectric constant is a negative value as in the plasma. A natural substance having a negative permeability is a paramagnetic substance. Both of these are positive values and are materials that reflect electromagnetic waves. When a plasmon or magnon has a nano-sized vector and has a clear vector, it interferes with the plasmon or magnon of an adjacent conductive powder, thereby causing a very large negative relative permittivity and relative permeability, for example, minus 1000 to 10 million. A value can be indicated. When both values are negative, the refractive index of the electromagnetic wave becomes negative, but it is a negative multiplication, and the electromagnetic energy passes through in order to keep the substance in a positive state.

The dimension of the vector that plasmon or magnon has will be described with reference to FIG. When the radius of the cylindrical conductive powder 42 in the insulating resin 41 is r, and the distance between the centers of the conductive powder 42 is a, Equation 1 is established for the plasma frequency _ωep . Here, n _eff = electron density, m _eff = electron effective mass, c ₀ = velocity of light, ε ₀ = dielectric constant in vacuum. This perturbation has a negative dielectric constant from the low frequency to the plasma frequency because of zero-order resonance. Since it is sufficient to have a clear vector, it is irrelevant to the length of the cylinder, and varies greatly with respect to the powder interval due to the mutual resonance relationship.

Similarly, the equation for the magnetic permeability can be expressed by Equation 2.

The capacitance C of the connection resin 3 between the connection terminals 11 and 21 can be expressed by C = Aε _r ε ₀ / d. However, since the relative dielectric constant is high as described above, a large connection capacitance can be obtained. Where C is the capacitance [F], A is the electrode area [m ² ], d is the dielectric thickness [m], ε _r is the relative dielectric constant, ε ₀ is the dielectric constant [F / m] in vacuum = 8.854 × 10 ^-12 . The capacity C of the connecting resin 3 is mainly derived from the first conductive powder 32.

Also, when the connection terminals 21 respectively to the connection terminals 11 in a coil shape, the inductance L of the connecting terminals 11 and 21 large inductive connection can be established in relation _{L = dμ r μ 0 / A} . Here, L is the inductance [H], A is the area [m ² ] of the connection terminals 11 and 21, d is the thickness [m] of the connection terminals 11 and 21, μ _r is the relative permeability, and μ ₀ is the permeability in vacuum. Magnetic permeability [H / m] = 1.25 × 10 ⁻⁶ . In this case, composite coupling of capacitive coupling and inductive coupling can be easily realized by the present invention, and a frequency from a frequency close to DC to a high frequency can be joined in a non-contact manner. The electromagnetic energy can be transmitted by the electric field E and the magnetic field H, and W = EHwd [W], which is proportional to the size of C and L. Also, DC power can be supplied by mixing flakes for metal contact.

  As described above, according to the present invention, the connection terminals can be electrically connected using capacitive coupling. In addition, labor required for connection is reduced compared to the case where the connection terminals are connected by solder. Further, when the connecting resin 3 after solidification is made flexible, the interface deviation can be made unquestioned. As a result, the connection with flexibility can be made, and the stress generated in the joint portion can be reduced. it can. Further, the connection terminals 11 and 21 can be detachable from the connection resin 3. In this case, design freedom and ease of inspection and repair can be ensured.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

Sectional drawing for demonstrating the junction structure of the board | substrate 1 and electronic component 2 which concern on embodiment. The principal part enlarged view of FIG. The figure which shows the state which removed the connecting terminal 21 from the resin 3 for a connection. The figure explaining the dimension of the vector which plasmon and magnon have.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 2 ... Electronic component, 3 ... Connection resin, 11, 21 ... Connection terminal, 31, 41 ... Resin, 32 ... 1st electrically conductive powder, 33 ... 2nd electrically conductive powder, 42 ... Conductive powder body

Claims (11)

Insulating resin, a plurality of first conductive powders mixed in the resin and having an average particle diameter of 5 nm to 500 nm, and a plurality of first conductive powders mixed in the resin and having an average particle diameter of 500 nm to 20 μm Applying a connection resin having a second conductive powder to the first connection terminal;
Connecting the first connection terminal and the second connection terminal via the connection resin;
Solidifying the connecting resin;
Comprising
In the connection resin after solidification, at least some of the plurality of first conductive powders are dispersed in the connection resin in a state of being separated from each other, and the plurality of second conductive powders A part of the method of connecting the terminals connecting the first connection terminal and the second connection terminal by contacting each other. An insulating resin having flexibility in a solidified state, a plurality of first conductive powders mixed in the resin and having an average particle size of 5 nm to 500 nm, and mixed in the resin, the average particle size is Applying a connection resin having a plurality of second conductive powders of 500 nm or more and 20 μm or less to the first connection terminals;
Solidifying the connecting resin;
Connecting the first connection terminal and the second connection terminal via the connection resin;
Comprising
In the connection resin after solidification, at least some of the plurality of first conductive powders are dispersed in the connection resin in a state of being separated from each other, and the plurality of second conductive powders A part of the method of connecting the terminals connecting the first connection terminal and the second connection terminal by contacting each other.   The terminal connection method according to claim 2, wherein the insulating paste is applied to one surface of the first connection terminal. A first connection terminal;
A second connection terminal;
Insulating resin, a plurality of first conductive powders mixed in the resin and having an average particle diameter of 5 nm to 500 nm, and a plurality of first conductive powders mixed in the resin and having an average particle diameter of 500 nm to 20 μm A second conductive powder, and a connection resin for connecting the first connection terminal and the second connection terminal;
Comprising
At least a part of the plurality of first conductive powders is dispersed in the connecting resin in a state of being separated from each other, and a part of the plurality of second conductive powders is brought into contact with each other, thereby A junction structure of a terminal connecting the first connection terminal and the second connection terminal.   The terminal connection structure according to claim 4, wherein the connection resin has flexibility and is removable from at least one of the first connection terminal and the second connection terminal. The plurality of first conductive powders transmit an AC component of a signal between the first connection terminal and the second connection terminal,
The terminal joining structure according to claim 4 or 5, wherein the plurality of second conductive powders transmit a DC component of a signal between the first connection terminal and the second connection terminal.   The mixing amount of the plurality of second conductive powders with respect to the plurality of first conductive powders is not less than 2 times and not more than 20 times by weight ratio. Junction structure.   The terminal connecting structure according to claim 4, wherein the connecting resin has a relative dielectric constant of 1000 or more.   The terminal bonding structure according to claim 4, wherein the connecting resin has a relative magnetic permeability of 10 or more.   The junction structure of a terminal according to any one of claims 4 to 9, wherein the connection resin has a thickness of 500 nm or more and 50 µm or less. An insulating resin;
A plurality of first conductive powders mixed in the resin and having an average particle size of 5 nm or more and 500 nm or less;
A plurality of second conductive powders mixed in the resin and having an average particle size of 500 nm or more and 20 μm or less;
A connecting resin comprising:

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