JP2002368182A - Resin-sealed electronic device and method of manufacturing the same - Google Patents

Abstract

(57) Abstract: A resin for sealing an IC chip in a resin-sealed electronic device in which an IC chip and other electronic components mounted on a circuit board are respectively sealed with different resins. So that it does not come into contact with other electronic components. SOLUTION: An IC chip 2 is sealed with a first resin 6 on one surface 1a of a circuit board 1, and other electronic components 3 are sealed.
Is sealed with the second resin 7, the second resin 7
As a method, a material having a lower fluidity at the time of application than the first resin 6 is used, and a step of applying and curing the second resin 7 is performed first, and then the first resin 6 is applied and cured. Is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-sealed type in which a semiconductor chip and other electronic parts are mounted on a circuit board, and the semiconductor chip and other electronic parts are respectively sealed with different resins. The present invention relates to an electronic device and a method for manufacturing the same.

[0002]

2. Description of the Related Art A general structure of a conventional electronic device of this type is shown in FIG. This electronic device has one surface 1a of the circuit board 1.
After mounting the semiconductor chip 2 and other electronic components 3 such as capacitors via the conductive adhesive 4, the semiconductor chip 2 is connected to the circuit board 1 by bonding wires 5, and the semiconductor chip 2 and the wires 5 are connected. The electronic component 3 is sealed with a first resin 6 such as an epoxy resin, and then the other electronic components 3 are sealed with a second resin 7 such as a silicone rubber.

[0003]

However, in this type of electronic device, the distance between each mounted component is shortened due to the demand for high-density mounting, and the first resin 6 provided earlier is not used.
May come into contact with other electronic components 3.

In such a case, a stress is generated during a cooling / heating cycle due to a difference in thermal expansion coefficient between the first resin 6 and the other electronic components 3, and a connection portion of the other electronic components 3, that is, a conductive adhesive. There is a possibility that cracks may occur in the first resin 4 and the first resin 6.

Accordingly, the present invention has been made in view of the above problems, and has a semiconductor chip and other electronic components mounted on a circuit board.
In a resin-sealed electronic device in which a semiconductor chip and other electronic components are respectively sealed with different resins, an object is to prevent a resin sealing a semiconductor chip from coming into contact with other electronic components. And

[0006]

The above problem is due to the fact that the resin (the first resin) for encapsulating the semiconductor chip is dripped at the time of application. Is difficult to select. On the other hand, the resin (the second resin) for sealing other electronic components is different from the first resin.
There are many types of materials that can be selected, and a material that is less likely to sag than the first resin can be selected. The present invention has been implemented with a focus on such ease of material selection.

That is, according to the first aspect of the present invention, the semiconductor chip (2) is provided on one surface (1a) of the circuit board (1).
And mounting the other electronic components (3) and electrically connecting them, and sealing the semiconductor chip with the first resin by applying and curing the first resin (6) on the semiconductor chip. A resin-sealing-type electronic device including a step of stopping and a step of applying and curing the second resin (7) on the other electronic components to seal the other electronic components with the second resin. In the manufacturing method of the device, a resin having a lower fluidity at the time of application than the first resin is used as the second resin, and after performing the step of applying and curing the second resin, the first resin is removed. A step of applying and curing is performed.

According to the present invention, a first method for sealing a semiconductor chip is provided.
Before the first resin, the second resin having lower fluidity at the time of application than the first resin is applied and cured. Since the second resin having a relatively low fluidity (hard to flow) does not easily sag, there is a possibility that the second resin may enter the area where the first resin is arranged, that is, the area where the semiconductor chip is arranged, during application. Is less.

After the second resin is cured, even if the first resin having relatively high fluidity (easy to flow) is applied, other electronic parts are already sealed with the second resin. And other electronic components
No contact with the resin.

Therefore, according to the present invention, it is possible to prevent the resin for sealing the semiconductor chip from coming into contact with other electronic components. In addition, a resin-sealed electronic device capable of high-density mounting is provided.

Here, an epoxy resin can be used as the first resin (6) and a silicone rubber or silicone gel can be used as the second resin (7).

According to a third aspect of the present invention, there is provided a circuit board (1), a semiconductor chip (2) mounted on one surface (1a) of the circuit board, and other electronic components (3), On one surface of the circuit board, the semiconductor chip is sealed only with the first resin (6), and other electronic components are sealed only with the second resin (7) having a higher thixotropic property than the first resin. The electronic device is characterized in that the boundary portion where the first resin and the second resin are in contact with each other is located away from other electronic components.

According to the present invention, there is provided a resin-sealed electronic device.
It is manufactured by the manufacturing method of
This is the same as the first aspect of the present invention.

The reference numerals in parentheses of the above means are examples showing the correspondence with specific means described in the embodiments described later.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention. FIG. 1 is a diagram showing a schematic cross-sectional configuration of a resin-sealed electronic device S1 according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a circuit board made of a ceramic substrate, a printed board, or the like, and an IC chip (semiconductor chip) 2 and
Other electronic components 3 such as a capacitor and a resistance element (a capacitor in the illustrated example) are mounted.

The IC chip 2 and other electronic components 3
The circuit board 1 is adhered and fixed to one surface 1a via a conductive adhesive 4 made of Ag paste or the like. The IC chip 2 and pads (not shown) formed on one surface 1a of the circuit board 1 are connected and electrically connected by wires 5 formed by wire bonding of Au, Al, or the like.

The connection between the IC chip 2 and the wire 5 is wrapped and sealed only with the first resin 6 made of epoxy resin or the like, and the other electronic components 3 are sealed with the first resin 6. It is wrapped and sealed only with the second resin 7 made of silicone rubber, silicone gel, or the like having a lower fluidity at the time of application.

The first resin 6 and the second resin 7 are arranged so that their formation regions do not overlap each other, and the boundary between the first resin 6 and the second resin 7 is in contact with each other. Reference numeral 8 is located at a position distant from the other electronic components 3. Each component 2, 3, 5 sealed with these resins 6, 7
Is moisture-proof.

Although not shown, a terminal member such as a clip for connecting to an external wiring member is soldered to an end of the circuit board 1, and the circuit board 1 is connected to the outside via the terminal member. Electrical continuity is realized.

Next, a method of manufacturing the resin-sealed electronic device S1 will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view showing a state in the middle of the manufacturing process in a cross section corresponding to FIG.

First, although not shown, the terminal member is mounted on the end of the circuit board 1 and soldered (terminal member mounting step). Next, as shown in FIG.
The conductive adhesive 4 is printed on a predetermined portion of the one surface 1a, the IC chip 2 and other electronic components 3 are mounted on the printed conductive adhesive 4, and the conductive adhesive 4 is cured ( Electronic component mounting process).

Next, for example, by performing Au wire bonding, the IC chip 2 and the above-mentioned pads (not shown) of the circuit board 1 are connected via wires 5 and electrically connected (wire bonding). Process). By the electronic component mounting step and the wire bonding step, FIG.
As shown in (b), an IC chip (semiconductor chip) 2 and other electronic components 3 are mounted on one surface 1a of the circuit board 1 and are electrically connected.

Next, as shown in FIG. 2C, a second resin 7 is applied on the other electronic components 3 and cured, so that the other electronic components 3 are converted into the second resin 7. (The step of sealing the second resin).

More specifically, a silicone rubber is used as the second resin 7, and the silicone resin is applied by a dispenser or the like, and then heated at a temperature of, for example, 125 ° C. for 1 hour, thereby forming the second resin 7
To cure.

Next, the first resin 6 is applied onto the IC chip 2 and the wire 5 and cured, whereby the IC chip 2 and its wire connection portion are sealed with the first resin 6 (first resin 6). 1 resin sealing step).

More specifically, an epoxy resin is used as the first resin 6, and after being applied with a dispenser or the like, for example,
The first resin 6 is cured by heating at a temperature of 00 ° C. for 1 hour and further at a temperature of 150 ° C. for 3 hours. Thus, the resin-sealed electronic device S1 shown in FIG. 1 is completed.

By the way, in the above manufacturing method, the second
As the resin 7, the fluidity during application is the first resin 6.
After the step of applying and curing the second resin 7 using a smaller one, a step of applying and curing the first resin 6 is performed.

According to this, the second resin 7 having a relatively low fluidity at the time of application is unlikely to cause dripping (hard to flow) at the time of application, so that even if the second resin 7 is applied first, It is unlikely that the second resin 7 penetrates into the region where the first resin 6 is to be disposed during the application.

After the second resin 7 is cured, even if the first resin 6 having relatively high fluidity (easy to flow) is applied, the other electronic components 3 are already in the second resin. 7
The other electronic components 3 and the first resin 6 do not come into contact with each other.

Therefore, according to the above-described manufacturing method, it is possible to prevent the first resin 6 for sealing the IC chip 2 from directly contacting the other electronic components 3. For this reason, it is possible to prevent the occurrence of cracks due to stress generated by a cooling / heating cycle or the like as in the related art (see FIG. 3 described above).

In the present embodiment, the first resin 6 and the second resin 7 are in contact with each other at the boundary portion 8. However, since the resins are in contact with each other, the stress generated is such that the cracks are generated. Not big. Therefore, according to the present embodiment, the electronic device S1 suitable for high-density mounting can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a resin-sealed electronic device according to an embodiment of the present invention.

FIG. 2 is a process explanatory view showing a method for manufacturing the resin-sealed electronic device according to the embodiment.

FIG. 3 is a schematic sectional view showing a conventional general resin-sealed electronic device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Circuit board, 1a ... One side of a circuit board, 2 ... IC chip (semiconductor chip), 3 ... Other electronic components, 6 ... 1st resin, 7 ... 2nd resin, 8 ... 1st resin and 1st Boundary part where 2 resin contacts.

Claims (3)

[Claims] 1. A step of mounting a semiconductor chip (2) and other electronic parts (3) on one surface (1a) of a circuit board (1) and electrically connecting the semiconductor chip (2) and another electronic component (3); A step of sealing the semiconductor chip with the first resin by applying and curing the first resin (6); and applying a second resin (7) on the other electronic components. Encapsulating the other electronic component with the second resin by curing the electronic component with the second resin. Using a resin smaller than the first resin, performing a step of applying and curing the second resin, and then performing a step of applying and curing the first resin. A method for manufacturing a sealed electronic device. 2. The resin sealing mold according to claim 1, wherein an epoxy resin is used as the first resin (6), and silicone rubber or silicone gel is used as the second resin (7). A method for manufacturing an electronic device. 3. A circuit board comprising: a circuit board; a semiconductor chip mounted on one surface of the circuit board; and other electronic components mounted on the one surface of the circuit board. The semiconductor chip is sealed only with the first resin (6), and the other electronic components are sealed only with the second resin (7) having higher thixotropy than the first resin. A resin-sealed electronic device, wherein a boundary portion (8) where the first resin and the second resin are in contact with each other is located away from the other electronic components.