JPH10107400A - Printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain heat radiation effect and to simplify the control of adhesive supply amount in a case, where a semiconductor chip necessitating heat radiation such as TAB component is joined to a board with adhesive such as die attach agent. SOLUTION: A printed wiring board 4, on which a TAB component 3 is to be mounted, is provided with slits 7 in an area a slightly smaller than a semiconductor chip 3a of the TAB component 3 to be adhered with die attach agent 2. Excess applied die attach agent 2 is poured into the slits 7, so that it does not make contact with inner leads or the like which are conductors of the TAB component 3. A piece of metal is jointed to the semiconductor chip 3a for heat radiation through the slits from a side other than the side of the TAB component 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board on which electronic components such as semiconductor bare chips are mounted by using an adhesive such as a die attach agent, and more particularly, to a method for mounting electronic components requiring heat radiation. The present invention relates to a printed wiring board suitable for the present invention.

[0002]

2. Description of the Related Art In recent printed wiring boards, mounting density is increased by directly mounting surface mount components, semiconductor bare chips, and the like on a substrate.
Some components such as a semiconductor bare chip mounted on such a printed wiring board require heat radiation, and as a corresponding prior art, for example, Japanese Patent Application Laid-Open No. 6-8542.
There is one described in JP-A-7. In this technique, a through hole is provided in a printed wiring board corresponding to a lower portion of a semiconductor package, and the semiconductor package and the substrate are arranged in close contact with each other to achieve heat dissipation of the semiconductor component.

However, TAB (Tape Automated Bondin)
g) For printed wiring boards on which components are mounted, TA
Since the semiconductor chip of the B component and the printed wiring board are joined using an adhesive such as a die attach agent, when such a through hole is provided, the die attach agent flows out of the through hole, voids, etc. Can occur. Such outflow of the die attach agent from the through holes and generation of voids cause a reduction in bonding strength and heat radiation characteristics. In order to deal with such a problem, it is necessary to strictly control the application amount of the die attach agent.

As described above, the through-holes on the printed wiring board make it difficult to control the amount of the die-attaching agent applied, thereby causing a uniform application of the die-attaching agent and a reduction in heat radiation characteristics. If no through hole is provided, the heat dissipation effect cannot be obtained, and excessive die attach agent is pushed out from between the semiconductor chip and the printed wiring board, and comes into contact with the soldering connection points such as TAB parts and the inner leads. And cause a short circuit.

[0005]

The problem to be solved is that, in the prior art, when a semiconductor chip such as a TAB component which needs heat radiation is bonded by using an adhesive such as a die attach agent, the heat radiation effect is reduced. It is a point that maintenance and the management of the supply amount of the adhesive cannot be simplified. The purpose of the present invention is
An object of the present invention is to provide a printed wiring board that solves the problems of the related art and that can increase the efficiency of a semiconductor chip mounting process and increase the reliability of a mounting device.

[0006]

In order to achieve the above object, a printed wiring board of the present invention is a printed wiring board on which electronic components such as semiconductor bare chips are mounted using an adhesive such as a die attach agent. , Electronic parts (TAB parts 3)
A slit 7 is provided in the area of the portion (semiconductor chip portion 3a) to be bonded with the bonding agent (die attach agent 2), and the excess die attach agent 2 is poured into the slit 7 and passed through the slit 7. The heat-dissipating member (metal piece 5) inserted into contact with the semiconductor chip portion 3 a of the TAB component 3 is characterized in that the heat-dissipating member (metal piece 5) is brought into contact with the semiconductor chip portion 3 a of the TAB component 3.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a printed wiring board according to the present invention will be described by taking as an example the mounting of a TAB component having a semiconductor chip portion requiring heat radiation at the bottom. In this embodiment, TAB
When joining a semiconductor chip portion requiring heat radiation of a component and a printed wiring board with a die attach agent, the die attach agent is prevented from flowing out of through holes and the occurrence of voids and the like is suppressed.
In order to stably apply the die attach agent to the B component and achieve a heat dissipation structure, a slit is provided on the printed wiring board at a position slightly smaller than the mounting position of the semiconductor chip portion of the TAB component. As a result, an excess die attach agent when the TAB component is joined can be poured into the slit, the amount of the die attach agent between the TAB component and the printed wiring board can be stabilized, and an extra die attach agent can be obtained. It is possible to prevent the touch agent from being short-circuited to the inner lead or the soldered portion of the TAB component.

In addition, the heat radiation effect can be improved by passing a metal piece for heat radiation through the slit from the opposite surface of the printed wiring board on which the TAB component is mounted and directly joining the semiconductor chip portion. it can. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the configuration of the printed wiring board of the present invention according to the present invention.

In FIG. 1, 1 is a TAB lead, 2 is a die attach agent, 3 is a TAB component, 3a is a semiconductor chip portion requiring heat radiation, 4 is a printed wiring board of the present invention,
Denotes a heat radiating member, 6 denotes a thermal via, 7 denotes a slit according to the present invention, 8 denotes a polyimide film, and 9 denotes an inner lead. In the printed wiring board 4 of the present invention, a slit 7 penetrating from the mounting surface of the TAB component to the back surface is provided. The position of the slit 7 is set to a size slightly smaller than the size of the semiconductor chip portion 3a that needs to dissipate the heat of the TAB component 3. Furthermore, the slit 7 is TAB
Conductive plating is performed so that electrical continuity can be obtained between the component mounting surface and the back surface.

Further, as shown in FIG.
The metal piece 5 for heat radiation is brought into direct contact with the semiconductor chip portion 3a of the AB component 3 from the back surface through the slit 7. As a result, the printed wiring board 4 and the metal pieces 5
Heat can be radiated from both. At this time, in order to adhere and fix the metal piece 5 for heat radiation, it is also possible to join with an extra die attach agent in the slit. Next, a process of mounting the TAB component 3 on the printed wiring board 4 will be described with reference to FIG.

FIG. 2 is an explanatory view showing a general mounting process of a TAB component on the printed wiring board in FIG. 2A to 2C, the TAB component 3 is mounted on the printed wiring board 4 according to the present invention. That is, first, as shown in FIG. 2A, the die attach agent 2 is applied to the printed wiring board 4. At this time, the die attach agent 2 is applied to the area inside the slit 7 of the present invention. Thereafter, a flux for soldering is applied to the printed wiring board 4, and the cut and formed TAB component 3 is heated and connected to the printed wiring board 4.

The TAB component 3 is designed so that there is a slight gap between the semiconductor chip portion 3a of the TAB component 3 and the printed wiring board 4, and the die attach agent 2 is pressed by the semiconductor chip portion 3a of the TAB component 3. Is filled in the gap with the printed wiring board 4. At this time, extra die attach agent 2
Flows out of the slit 7 to the back side of the printed wiring board 4. Thus, the TAB component 3 can be connected without contacting the soldered portions of the TAB component 3 such as the inner lead 9 and the TAB lead 1.

As described above with reference to FIGS. 1 and 2, in the printed wiring board 4 of this embodiment, the slit 7 is provided so that the die attach Can be prevented from being short-circuited to the soldered portion (TAB lead 1) of the TAB component 3 or the inner lead 9 by the extra die attach agent 2. Further, the heat dissipating metal piece 5 can be directly attached to the semiconductor chip component 3a requiring heat dissipation of the TAB component 3 through the slit 7, and the heat dissipation characteristics can be improved.

The present invention is not limited to the embodiment described with reference to FIGS. 1 and 2, but can be variously modified without departing from the gist thereof. For example, in the present embodiment, the configuration in which the slit 7 is provided for one TAB component 3 has been described, but an extra slit having a different size can be additionally provided for a plurality of TAB components having different sizes.

[0015]

According to the present invention, even when a semiconductor chip such as a TAB component which requires heat radiation is bonded using an adhesive such as a die attach agent, the heat radiation effect can be maintained and the amount of adhesive supplied can be reduced. The management can be simplified, the efficiency of the semiconductor chip mounting process can be increased, and the reliability of the mounting device can be increased.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a configuration according to the present invention of a printed wiring board of the present invention.

FIG. 2 is an explanatory view showing a general mounting process of a TAB component on the printed wiring board in FIG. 1;

[Explanation of symbols]

1: TAB lead, 2: die attach agent, 3: TAB component, 3a: semiconductor chip part, 4: printed wiring board, 5:
Heat dissipation metal piece, 6: thermal via, 7: slit, 8:
Polyimide film, 9: inner lead.

Claims (1)

[Claims] 1. A printed wiring board on which an electronic component is mounted using an adhesive, wherein a slit is provided in a range of a portion of the electronic component which is bonded by the adhesive, and the electronic component is excessively applied. While pouring the adhesive member into the slit,
A printed wiring board, wherein a heat radiation member inserted through the slit is brought into contact with a portion of the electronic component to be bonded with the bonding agent.