JPH0547835A - Mounting structure of semiconductor device - Google Patents

Abstract

PURPOSE:To improve reliability after joining a TAB type semiconductor device with lead frames for being sealed with resin. CONSTITUTION:A TAB type semiconductor device 1 formed into an insulating film and lead frames 5 are connected to the electrodes 6 of a semiconductor device for being sealed with resin. Thereby, the surface and the rear of the semiconductor element 1 are directly conducted with resin. Thereby, after packaging invasion of impurities from outside the frames is excluded so as to improve reliability. Mounting structure of this semiconductor device uses no die pad.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more specifically, to a mounting structure for a semiconductor device in which adhesion between a resin encapsulant and a semiconductor element is improved and reliability after resin encapsulation is improved. It is about.

[0002]

2. Description of the Related Art Recently, the number of semiconductor elements mounted on electronic equipment has increased significantly, and the number of semiconductor elements having high functionality has also increased.

FIG. 4 (a) is a plan view showing an example of a conventional semiconductor device (hereinafter referred to as QFP) in which leads are provided on four sides of the package, and FIG. 4 (b) is a sectional view thereof. In the figure, 1 is a semiconductor element, and 2 is a circuit pattern formed on an insulating film. The side of the semiconductor element 1 that is connected to the electrode 6 may be referred to as the inner lead 2a, and the opposite side may be referred to as the outer lead 2b.

FIG. 3A is a plan view showing an example of a TAB type semiconductor device, and FIG. 3B is a sectional view thereof. In such a TAB type semiconductor device 7, after connecting the electrode 6 of the semiconductor device 1 and the inner lid 2b of the circuit pattern, forming is performed as shown in FIG. 3 (b), and the pad pad 4 of the lead frame of FIG. 4 (b) is formed. After fixing the semiconductor element 1 of the TAB type semiconductor device 7 by applying an adhesive to the outer lead 2b of the circuit pattern and the lead 3 of the lead frame and aligning and connecting them respectively, prevent deterioration of each of these elements. Therefore, it is sealed with resin 5 and each lead 3 of the lead frame is separated at a required length.

[0005]

As described above, semiconductor devices are required to be highly functional and a wide variety of types are available. Even if the number of leads after packaging and the outer size are the same, TAB
The size of the semiconductor element of the semiconductor device varies, and if the base pad of the lead frame and the size of the semiconductor element do not match, a dedicated lead frame must be prepared and the cost of the product increases.

Further, when fixing the TAB type semiconductor device to the base pad of the lead frame, the leads of the TAB type semiconductor device must be formed in accordance with the heights of the base pad and the leads of the lead frame, and each lead is the same. So it was difficult to form. If the leads are bent too much during this forming, cracks will occur and the strength at the time of joining will be reduced, or lead breakage will occur. Besides, TA
It is connected to the frame outside the encapsulation through a base pad fixed to the semiconductor element of the B type semiconductor device,
Impurities penetrate into the semiconductor device through this path, which causes a defect in the semiconductor element.

If the adhesive applied to the pedestal pad of the lead frame has a thermal expansion different from that of the resin sealant, stress may be applied to the pedestal pad and the semiconductor element of the TAB type semiconductor device to cause cracks in the semiconductor element. is there.

Further, since the pedestal pad of the lead frame and the encapsulating resin agent have poor adhesion, a gap is formed between the resin and the pedestal pad after packaging, and blistering occurs, so that the semiconductor element is defective after the resin encapsulation. There is something to do.

[0009]

A mounting structure of a semiconductor device according to the present invention is a TAB type semiconductor device in which inner leads of a circuit pattern formed on an insulating film are respectively connected to electrodes of a semiconductor element and an outer shape is cut, A lead frame having a large number of leads, each of which is connected to an outer lead of a circuit pattern of the TAB type semiconductor device and sealed with a resin, and the lead frame does not have a base pad portion. The resin is in direct contact with the front and back surfaces.

[0010]

1 (a) and 1 (b) are a plan view and a sectional view of an embodiment of the present invention. In the figure, 7 is the semiconductor element 1 on the inner lead 2a of the circuit pattern provided on the carrier film.
Is a semiconductor device (hereinafter referred to as a TAB type semiconductor device) to which the electrode 6 of FIG. This TAB type semiconductor device 7 is shown in FIG.
As shown in Fig. 1, a semiconductor element 1 is formed by forming a large number of circuit patterns 2 made of a copper foil or the like on a polyimide film.
And the circuit pattern 2 is cut at the alternate long and short dash point 8.

FIG. 2B shows a circuit pattern 2 and a semiconductor element 1.
It is sectional drawing cut | disconnected after connecting with. It is not necessary to form leads as shown in FIG. 3 (b).

Reference numeral 3 in FIG. 1 is a lead of a lead frame (hereinafter, simply referred to as a lead frame). 5 is a package sealed with an epoxy resin, for example. TA as above
The outer lead 2b of the B type semiconductor device 7 and the lead 3 of the lead frame are aligned and joined. After bonding, semiconductor device 1,
The circuit pattern 2 and the leads 3 of the lead frame are sealed with, for example, an epoxy resin to form a package 5, and the leads of the leads 3 are cut to an appropriate length and formed to complete the manufacturing of the semiconductor device. The sealing resin 5 is in direct contact with the front surface and the back surface of the semiconductor element 1, and the mounting structure of this semiconductor device does not use a stand pad for the lead frame.

[0013]

As is apparent from the above description, the present invention eliminates the conventional pad pad of the lead frame, which is a resin-sealed semiconductor element back surface fixing portion, and makes the front and back surfaces of the TAB semiconductor device the same. Since it was covered with resin, impurities from the outside did not enter through the base pad.
In addition, TA with the same package outer size and the same number of leads
If it is a B semiconductor device, semiconductor elements having different functions can be used. Further, since no adhesive is used for the base pad, the semiconductor element is not cracked due to the stress due to the difference in thermal expansion between the resin sealant and the adhesive. In addition, since the resin encapsulant comes into close contact with the semiconductor element directly from what has been in contact with the pedestal pad of the lead frame, the reliability after resin encapsulation is improved and it is also practically effective.

[Brief description of drawings]

FIG. 1A is a plan view of an embodiment of the present invention. (b) Its sectional view.

FIG. 2A is a plan view of an example of a TAB semiconductor device. (b) Its sectional view.

FIG. 3A is a plan view of an example of a TAB semiconductor device. (b) is a sectional view.

FIG. 4A is a plan view showing a mounting structure of a conventional semiconductor device. (b) Its sectional view.

[Explanation of symbols]

 1: Semiconductor element 2: Circuit pattern 3: Lead frame 4: Platform pad 5: Package 6: Semiconductor element electrode 7: TAB semiconductor device 8: Cutting line 9: Carrier film

Claims (1)

[Claims] 1. A TAB semiconductor device comprising a TAB semiconductor device in which inner leads of a circuit pattern formed on an insulating film are respectively connected to electrodes of a semiconductor element and the outer shape is cut, and a lead frame having a large number of leads. In a semiconductor device in which the outer leads of the circuit pattern of the device are respectively connected to the leads of the lead frame and sealed with resin, and the frame of the lead frame is separated, the lead frame does not have a pad part, A mounting structure of a semiconductor device, wherein a front surface and a back surface of a semiconductor element of the TAB type semiconductor device are in direct contact with the resin.