JPH0918121A - Electronic component mounting body and manufacturing method thereof - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce migration resistance by reducing connection resistance between electronic components and minute electrodes of a circuit pattern of a circuit board to reduce variation in current due to increase in current density. A bump electrode 4 of a semiconductor element 1 of an electronic component is made face-down and connected to a circuit pattern electrode 9 of a circuit board 7 with a conductive adhesive 12 containing Ag and other conductive particles. A synthetic resin 15 is interposed between the semiconductor element 1 and the circuit board 7 to fix both components.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to mounting of electronic parts and a circuit board which form an electric circuit.

[0002]

2. Description of the Related Art The conventional mounting of electronic components on a circuit board will be described below with reference to FIGS.
With the recent trend toward miniaturization and portability of electric products, higher density mounting of electronic components on a circuit board has been required. In mounting a semiconductor element, a method of directly mounting the semiconductor element on a circuit board has been adopted in order to increase the mounting density. Above all, mounting using bare chips is becoming commonplace.

In FIG. 6, the bare chip-shaped semiconductor element 1 is faced down and the protruding electrode 4 of the semiconductor element 1 is brought into contact with the circuit pattern electrode 9 of the circuit board 7,
A method of connecting via a conductive adhesive 14 is used. Ag conductive adhesive 14 contains Ag as a main component of conductive particles.
Therefore, synthetic resin is generally used as the remaining component. Also,
The distance between the plurality of adjacent protruding electrodes 4 of the semiconductor element 1 is
It is getting narrower year by year, and 100 μm is no longer rare.

Passive elements 3 such as resistors and capacitors
In many cases, solder is used for the connection between the electrode 6 and the circuit pattern electrode 9 on the circuit board 7. However, as shown in FIG. 7, the Ag conductive adhesive 1 is used because of the tendency of lead-free to prevent environmental pollution and pollution and low temperature treatment in the mounting process.
A method using 4 is being sought

[0005]

However, in the case of FIG.
Since the protruding electrode 4 of the semiconductor element 1 is as small as φ80 μm, the current density becomes high and the current tends to become unstable. Further, the distance between the adjacent protruding electrodes 4 of the semiconductor element 1 is 10
Since the width is as narrow as 0 μm, the electric field strength becomes large even in the low voltage region where the applied voltage is 1.5 V, and there is a problem that migration due to elution of Ag ions in the Ag conductive adhesive 14 is likely to occur due to an increase in humidity and dew condensation.

Further, in FIG. 7, Ag conductive adhesive 14 is used to connect the passive element 3 and the circuit pattern electrode 9 of the circuit board 7. As a result, as shown in the plan view of FIG. 8, the Ag conductive adhesive 14 interposed on the electrode 6, the electrode 24, the circuit pattern electrode 9, and the circuit pattern electrode 21 connected to the adjacent passive element 3 and the passive element 23. Due to the voltage applied between both circuit patterns and the presence of water, Ag ions are generated on the anode side.
It is eluted from the conductive adhesive 14 and is deposited in the dendrite shape on the circuit pattern electrode 9 on the cathode side to form a deposited metal 22.
There is a problem that the circuit pattern electrode 21 on the anode side grows and short-circuits.

The present invention has been made to solve the above problems, and provides an electronic component mounting body and a method of manufacturing the same that can achieve a high current density even when connecting microelectrodes and can minimize the distance between adjacent electrodes in terms of electric field strength. The purpose is to do.

[0008]

In order to solve the above problems, in the electronic component mounting body of the present invention, conductive particles Ag are included in the bonding and connection between the electrodes of the electronic component and the circuit pattern electrodes of the circuit board. A conductive adhesive made of a mixed particle of conductive particles and a synthetic resin such as an epoxy resin was used, and a synthetic resin was interposed between both parts outside the bonding site to fix the parts.

In the method for manufacturing an electronic component package of the present invention, the electrode of the electronic component or the circuit pattern electrode of the circuit board is made of a mixed particle of conductive particles containing conductive particles Ag and a synthetic resin such as epoxy resin. Applying a conductive adhesive, aligning the electrode of the electronic component and the circuit pattern electrode of the circuit board and bonding the two electrodes with the conductive adhesive, semi-curing the conductive adhesive, and further A synthetic resin was injected between both parts outside the bonding site to be cured.

In another method of manufacturing an electronic component package according to the present invention, mixed particles of conductive particles containing conductive particles Ag and epoxy on a circuit pattern electrode of a circuit board at a position where an electrode of an electronic component is in contact. Apply a conductive adhesive made of synthetic resin such as resin, apply synthetic resin to the corresponding parts of the electronic component and the circuit board other than the conductive adhesive application, and align the circuit pattern electrodes of the electronic component and the circuit board. Then, the two electrodes are bonded and connected with a conductive adhesive, and the electronic parts and the circuit board are bonded and connected and fixed with a synthetic resin in the other portions.

Further, as the conductive particles to be combined with Ag of the conductive adhesive, one made of copper, tin and one of transition metals such as chromium and palladium is effective. As described above, it is possible to obtain an electronic component package and a method for manufacturing the same, which solve the above problems.

[0012]

According to the present invention configured as described above, even if the microelectrodes are further advanced and the current density is increased, the current stability is improved by the other conductive particles, and the adhesive interface resistance is reduced. As a result, the electrical characteristics are improved due to the reduction of the capacitive component, and the elution of Ag ions can be suppressed to reduce the occurrence of migration.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a structural diagram of an electronic component mounting body according to an embodiment of the present invention.

A semiconductor element 1 having about 200 bump electrodes 4 each having a height of about 75 μm and a diameter of about 80 μm arranged at a pitch of 120 μm is faced down to a circuit pattern electrode 9 of a circuit board 7 with a conductive adhesive 12. After the connection, the insulating synthetic resin 15 is interposed between the semiconductor element 1 and the circuit board 7 to fix both components, and the conductive adhesive 12 protects the connected portion from shearing.

The conductive adhesive 12 comprises Ag conductive particles having an average particle size of 1 μm or less and 2 to 10 wt% having a particle size of 1 to 3 μm.
% Of the conductive particles other than Ag are contained in the one-component epoxy resin as mixed particles in an amount of 70 to 90%. The curing conditions of the conductive adhesive 12 were set so as to be cured by heating at 125 ° C. for 15 minutes in consideration of mass productivity and influence on electronic parts.

Regarding the connection resistance value of this electronic component mounting body, as a result of confirming the materials of the electrode 4 of the semiconductor element 1 and the circuit pattern electrode 9 of the circuit board 7 for three kinds of Au, ITO and Al, the conventional single resistance value is obtained. Conductive adhesive 12 in which 2 to 10 wt% of other conductive particles chromium or palladium is added to Ag conductive particles as compared with Ag conductive adhesive 14 of
It was found that the above condition contributed to the decrease of connection resistance and the increase of current density.

On the other hand, in the presence of water at a distance of 40 μm above the insulating material between adjacent 120 μm pitch electrodes, 1.5 V
In the migration confirmation by the elution of the Ag ion on the anode side by voltage application and the deposition growth on the cathode side, the electroconductivity was obtained by adding 2 to 18 wt% of one other conductive particle among copper, tin, chromium and palladium to the Ag conductive particle. Adhesive condition is A
It was confirmed that migration could be prevented more significantly than the conductive adhesive containing only g.

(Embodiment 2) FIG. 2 is a structural diagram of an electronic component mounting body of another embodiment according to the present invention. The circuit pattern electrode 10 formed on the plurality of protrusions 81 of the circuit board 8 using a part of the plastic panel and the electrode 5 of the semiconductor element 2 are connected by the conductive adhesive 12, and the insulating synthetic resin 15 is used.
Both parts are fixed with. In this embodiment, the semiconductor device 2
The electrode 5 is a concave electrode surrounded by the passivation layer 11.

Regarding the connection resistance value of this electronic component mounting body, the materials of the electrode 5 of the semiconductor element 2 and the circuit pattern electrode 9 and the circuit pattern electrode 10 of the circuit board 8 were confirmed for three kinds of Au, ITO and Al. As a result, conventional single A
The condition of the conductive adhesive 12 in which 2 to 10 wt% of other conductive particles chromium or palladium is added to Ag conductive particles as compared with the conductive adhesive 14 contributes to the decrease of the connection resistance value and the increase of the current density. I found out.

On the other hand, in the presence of water at a distance of 40 μm above the insulating material between the electrodes of 120 μm pitch adjacent to each other, 1.5 V
In the migration confirmation by the elution of the Ag ion on the anode side by voltage application and the deposition growth on the cathode side, the electroconductivity was obtained by adding 2 to 18 wt% of one other conductive particle among copper, tin, chromium and palladium to the Ag conductive particle. Adhesive condition is A
It was confirmed that migration could be prevented more significantly than the conductive adhesive containing only g.

(Embodiment 3) FIG. 3 is a structural view of an electronic component mounting body of another embodiment according to the present invention. The electrode 6 of the passive element 3 and the circuit pattern electrode 9 of the circuit board 7 are connected by a conductive adhesive 12, and further both parts are fixed by a synthetic resin 15.

The conductive adhesive 12 comprises Ag conductive particles having an average particle size of 1 μm or less and 2 to 10 wt% having a particle size of 1 to 3 μm.
% Of the conductive particles other than Ag are contained in the one-component epoxy resin as mixed particles in an amount of 70 to 90%. The curing conditions of the conductive adhesive 12 were set so as to be cured by heating at 125 ° C. for 15 minutes in consideration of mass productivity and influence on electronic parts.

In addition, both the Ag conductive adhesive and the conductive adhesive obtained by adding other conductive particles to the Ag conductive particles have an adhesive strength of adhesion and connection between the electrode of the electronic component and the circuit pattern electrode of the circuit board. It becomes weaker than the adhesive strength of the epoxy resin adhesive that does not contain particles.Therefore, when using a conductive adhesive to bond and connect the electrodes,
It was found that fixing and reinforcing both connected parts with an insulating synthetic resin is effective for impact resistance, thermal shock resistance, thermal cycle and moisture resistance.

Example 4) FIGS. 4 (A) to 4 (E) are schematic explanatory views of a manufacturing process of an electronic component mounting body according to the present invention. First, as shown in FIG. 4 (A), a conductive adhesive 12 composed of a mixed particle of Ag conductive particles and other conductive particles and a synthetic resin such as epoxy resin is placed on a rotating table 25 coated with Teflon. It is discharged and is formed into a uniform film thickness of about 30 μm by the blade 16 for film formation. Next in FIG.
The conductive adhesive 12 having a uniform film thickness of about 30 μm is applied to the circuit pattern electrodes 10 formed on the plurality of protrusions 81 having a height of about 75 μm on the circuit board 8 formed of a part of the plastic liquid crystal panel shown in FIG. FIG. 4C shows this state in which the circuit pattern electrode 10 is transferred and applied. Further, the semiconductor element 2 is made face-down and the semiconductor element 2
The concave electrode 5 opened in the passivation layer 11 is aligned with and connected to the circuit pattern electrode 10 coated with the conductive adhesive 12. This state is shown in FIG. 4 (D).
It is. Finally, the conductive adhesive 12 is semi-cured by heating for several minutes, and then the insulating synthetic resin 15 is applied between the semiconductor element 2 and the circuit board 8 to bond the two parts together, and the conductive adhesive is applied in the heating step. The agent 12 and the synthetic resin 15 are cured to complete the mounting manufacturing process, and an electronic component mounting body is obtained. This state is shown in FIG.

(Embodiment 5) FIGS. 5 (A) to 5 (F)
FIG. 8 is a schematic explanatory view of a manufacturing process of another embodiment of an electronic component mounting body according to the present invention. A print mask 18 is aligned and fixed on the circuit board 7 and the circuit pattern electrode 9 of FIG. 5A, and a conductive material composed of a mixed particle of Ag conductive particles and other conductive particles and a synthetic resin such as epoxy resin. Adhesive 13
Is discharged onto the printing mask 18 to print the squeegee 17
While pressing it against the print mask 18, slide (Fig.
As shown in (B), the conductive adhesive 13 is imprinted on the opening 19 of the print mask 18 to print, and the conductive adhesive 13 is formed on the circuit pattern electrode 9 of the circuit board 7 (see FIG. See C)). Next, as shown in FIG. 5D, an insulating synthetic resin 15 such as an epoxy resin is applied onto the circuit board 7 by the discharge nozzle 20 to form the synthetic resin 15 (see FIG.
(See (E)), the electrode 6 of the passive element 3 is aligned with the circuit pattern electrode 9, and the conductive adhesive 13 is provided between the electrodes 6 and 9, and the synthetic resin 15 is used to provide the components 3 and 7. The parts are adhered together, connected and fixed by a heating process, and the mounting manufacturing process is completed to obtain an electronic component mounting body (FIG. 5).
(F)).

[0026]

The present invention uses a conductive adhesive composed of a mixed particle of Ag conductive particles and other conductive particles and a synthetic resin, and as a result, the connection between the electronic parts and the microelectrodes of the circuit pattern of the circuit board. Not only did the resistance decrease and the variation in current due to the increase in current density could be reduced by an order of magnitude, but Ag ion elution and precipitation due to the presence of water and the electric field associated with voltage application was reduced to 1 to 44%. It is drastically reduced and it is remarkably effective in preventing migration. Further, there is an effect of preventing pollution due to lead-free due to no use of solder, and it is possible to provide an electronic component mounting body having stable quality from a low-temperature treatment step in which the curing temperature of the conductive adhesive is 125 ° C.

[Brief description of the drawings]

FIG. 1 is a structural diagram of an electronic component mounting body according to an embodiment of the present invention.

FIG. 2 is a structural diagram of an electronic component mounting body according to another embodiment of the present invention.

FIG. 3 is a structural diagram of an electronic component mounting body according to another embodiment of the present invention.

FIG. 4 is a schematic explanatory view of a manufacturing process of an example of an electronic component mounting body of the present invention.

FIG. 5 is a schematic explanatory drawing of a manufacturing process of another embodiment of the electronic component mounting body of the present invention.

FIG. 6 is a structural diagram of a conventional electronic component mounting body.

FIG. 7 is a structural diagram of another conventional electronic component mounting body.

FIG. 8 is a plan view of another conventional electronic component mounting body.

[Explanation of symbols]

 1, 2 Semiconductor element 3 Passive element 4 Projection electrode 5, 6 Electrode 7, 8 Circuit board 9, 10 Circuit pattern electrode 11 Passivation layer 12 Conductive adhesive 14 Ag Conductive adhesive 15 Synthetic resin

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hitoshi Takeuchi, 1-8 Nakase, Mihama-ku, Chiba, Chiba Prefecture SII Co., Ltd. Earl Di Center (72) Inventor Taikichi Ishii, Nakase, Mihama-ku, Chiba, Chiba 8-chome Co., Ltd. SII RD Center (72) Inventor Hiroshi Okano 1-8 Nakase, Mihama-ku, Chiba, Chiba Pref. SII RD Center Co., Ltd.

Claims (7)

[Claims] 1. An electronic component mounting body, comprising a conductive adhesive composed of a conductive mixed particle containing at least Ag and a synthetic resin between an electrode of an electronic component and an electrode on a circuit board. 2. The electronic component mounting body according to claim 1, wherein a part of the components of the mixed particles is made of a transition metal. 3. The electronic component package according to claim 2, wherein the transition metal is selected from chromium and palladium. 4. A component of a part of the mixed particles is copper,
The electronic component package according to claim 1, wherein the electronic component package is selected from one of tin. 5. A surface not having electrodes of the element and the substrate, which has a conductive adhesive composed of conductive mixed particles containing Ag and a synthetic resin between the electrodes of the electronic component and the electrodes on the circuit board. An electronic component mounting body having an insulating adhesive on a surface not including an upper electrode. 6. A step of applying a conductive adhesive composed of a mixed particle of conductive particles Ag and other conductive particles and a synthetic resin to one of an electrode of an electronic component or a circuit pattern electrode of a circuit board, A step of aligning the electrode of the component and a circuit pattern electrode of the circuit board; a step of adhering with the conductive adhesive; a step of semi-curing the conductive adhesive; A method of manufacturing an electronic component package, comprising: a step of injecting a synthetic resin between a component and the circuit board; and a step of curing the conductive adhesive and the synthetic resin. 7. A step of applying a conductive adhesive composed of a mixed particle of conductive particles Ag and other conductive particles and a synthetic resin to an electrode of a circuit board with which an electrode of an electronic part is in contact, A step of applying a synthetic resin to a mounting portion of the electric component excluding an electrode part of the electric component, a step of aligning the electrode of the electric component with a circuit pattern electrode of a circuit board, the conductive adhesive and the synthetic resin And a step of curing the conductive adhesive and the synthetic resin, the method for manufacturing an electronic component packaged body.