JP2001257217A - Structure and method for mounting semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the mounting strength of a semiconductor device at the time of mounting the device on a mounting substrate, by increasing the joining spots between the device and substrate when a lead section arranged on the bottom face of the device is joined to the substrate by soldering. SOLUTION: The semiconductor device is mounted on the mounting substrate by joining the exposed bottom face section and one external side face of a lead section 2 arranged on the bottom face of the device to the substrate by soldering 8 and, in addition, the terminal end sections 3a of a hanging lead section 3 which is exposed on the bottom face of the device and has no electrical relation with the device are joined to the substrate by soldering 8 as mounting reinforcing sections. Consequently, the number of joining spots is increased and, accordingly, the mounting strength is improved and the influence of the stress which is impressed upon the device depending upon the used condition of the device is eliminated. Therefore, the reliability of secondary mounting can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device mounting structure in which electrode terminals such as leads arranged on the bottom surface of a semiconductor device are mounted on a printed circuit board using a bonding material, and a method of mounting the semiconductor device. More particularly, the present invention relates to a semiconductor device mounting structure and a semiconductor device mounting method capable of improving the mounting strength and improving the reliability of the secondary mounting in the substrate mounting.

[0002]

2. Description of the Related Art Conventionally, as a method of mounting a semiconductor device on a printed circuit board on which wiring has been formed, a lead portion disposed on the bottom surface of the semiconductor device has been mounted using solder as a bonding material.

A conventional semiconductor device mounting structure and a conventional semiconductor device mounting method will be described below with reference to the drawings.

FIGS. 5 and 6 show a conventional semiconductor device mounted on a printed circuit board. FIG. 5A is a plan view and FIG. 5B is a bottom view. FIG. 6A is a perspective plan view showing the internal configuration, and FIG. 6B is a sectional view taken along line AA in FIG.
FIG. 6C is a cross-sectional view of one location B-B1 in FIG. 6A.

In a conventional semiconductor device mounted on a substrate, as shown in FIG. 5, leads 2 are arranged on the bottom surface of a sealing resin 1 constituting a package, and hanging leads 3 has a structure in which the end 3a is exposed. Specifically, as shown in FIG. 6, a semiconductor element 4, a die pad portion 5 supporting the semiconductor element 4, and a die pad portion 5
, A lead portion 2 having a tip portion disposed on a die pad portion 5, a thin metal wire 6 electrically connecting the lead portion 2 and the semiconductor element 4,
The terminal 3a of the suspension lead 3 and one side and bottom of the lead 2 are exposed, and the semiconductor element 4, the die pad 5,
This is a semiconductor device including a sealing resin 1 in which the outer periphery of the thin metal wire 6 is sealed. In FIG. 6, the semiconductor element 4 is shown by a broken line.

In order to mount the conventional semiconductor device configured as described above on a mounting substrate such as a printed circuit board, as shown in a sectional view showing the mounting structure of FIG. 7 and the connection portions such as wiring and the like are mounted using solder 8.

In other words, in the conventional mounting of the semiconductor device, the leads 2 arranged on the bottom surface of the semiconductor device and the mounting substrate 7 are joined by the solder 8.

[0008]

However, in the conventional mounting structure of a semiconductor device, the mounting strength may not be sufficient for mounting on a substrate, and a mounting structure with further improved bonding strength is required. That is, conventionally, the bottom surface and one exposed side surface of the lead portion arranged on the bottom surface of the semiconductor device are joined to the mounting board by soldering, and the mounting strength is insufficient because the number of joints is small. was there. Particularly, stress may be applied depending on the use state after mounting on the board, and there is a possibility that the conventional mounting structure cannot cope with such severe use conditions.

Further, QFP (Quad Flat Pac)
In the case where the lead portion protrudes from the package body as in the case of a semiconductor device such as a semiconductor device such as a semiconductor device, the bottom surface and each side surface of the lead portion can be joined with a joining material such as solder at the time of mounting on a substrate, so that a joining portion can be secured. However, recent QFNs (Quad Flat Non-leaded) in which the above-described leads are arranged on the surface can be obtained.
(Package) demanded an improvement in mounting strength.

The present invention solves the above-mentioned problems in the conventional mounting structure of a semiconductor device, and in a recent QFN type semiconductor device, dramatically improves the mounting strength and eliminates the influence of the use situation, It is an object of the present invention to provide a semiconductor device mounting structure and a semiconductor device mounting method capable of improving mounting reliability.

[0011]

In order to solve the above-mentioned conventional problems, a mounting structure of a semiconductor device according to the present invention comprises a lead portion for electrical connection on a bottom surface thereof, and a die pad supporting a sealed semiconductor element. A mounting structure of a semiconductor device in which a semiconductor device in which end portions of suspension leads that support a portion are arranged is mounted on a mounting board, at least a bottom surface of the lead portion is mounted with a bonding material, and mounting reinforcement is provided. FIG. 4 is a mounting structure of the semiconductor device in which a terminal portion of the suspension lead portion exposed from a bottom surface of the semiconductor device is mounted with a bonding material.

More specifically, a semiconductor element, a die pad portion supporting the semiconductor element, a suspension lead portion supporting the die pad portion at a tip end thereof, and a lead portion having a tip end portion arranged on the die pad portion Connecting means for electrically connecting the lead portion and the semiconductor element, and exposing an end portion of the suspension lead portion and one side surface and bottom surface of the lead portion, the semiconductor element, the die pad portion, A mounting structure of a semiconductor device in which a semiconductor device made of a sealing resin that seals the outer periphery of the connection means is mounted on a mounting substrate, and one side surface and a bottom surface of the lead portion are mounted with a bonding material, This is a mounting structure of a semiconductor device in which a terminal portion of a suspension lead portion exposed from an end portion of a bottom surface of the semiconductor device as a mounting reinforcing portion is mounted with a bonding material.

The method of mounting a semiconductor device according to the present invention may further comprise a semiconductor element, a die pad supporting the semiconductor element, a suspension lead supporting the die pad at its tip, and a tip attached to the die pad. The arranged lead portion, connection means for electrically connecting the lead portion and the semiconductor element, and exposing the end portion of the suspension lead portion and one side surface and the bottom surface of the lead portion, the semiconductor element, When mounting the die pad portion, a semiconductor device made of a sealing resin that seals the outer periphery of the connection means on a mounting substrate, mounting one side surface and the bottom surface of the lead portion of the semiconductor device with a bonding material A method of mounting a semiconductor device in which a terminal of a suspension lead exposed from an end of a bottom surface of the semiconductor device as a mounting reinforcing portion is also mounted with the bonding material.

The bonding material uses solder, and is used for mounting a semiconductor device on a printed circuit board.

As described above, in addition to the structure in which the exposed bottom surface portion of the lead portion disposed on the bottom surface of the semiconductor device and one outer side surface are joined to a mounting substrate by soldering,
The structure is such that the end of the electrically unrelated suspension lead exposed on the bottom surface is also joined to the mounting board as a mounting reinforcement, and the number of joints increases, dramatically increasing the mounting strength. In addition, it is possible to eliminate the influence of the stress applied depending on the use condition and improve the reliability of the secondary mounting.

In particular, when the end portions of the exposed suspension leads are arranged at the ends of the corners of the bottom surface (mounting surface) of the semiconductor device, the mounting strength is improved and the mounting reliability is improved by balancing the mounting balance. Performance can be improved.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a semiconductor device mounting structure and a semiconductor device mounting method according to the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show a semiconductor device mounted on a printed circuit board according to this embodiment.
1A is a plan view, and FIG. 1B is a bottom view. FIG.
2A is a perspective plan view showing an internal configuration, FIG. 2B is a cross-sectional view taken along a line C-C1 in FIG. 2A, and FIG.
It is sectional drawing of DD1 location of (a).

As shown in FIG. 1, in the semiconductor device mounted on a substrate according to the present embodiment, a lead portion 2 exposes the bottom surface and one outer side surface at the end of the bottom surface of a sealing resin 1 constituting a package. The end portions 3a of the suspension leads 3 are exposed at the ends of the respective corners of the sealing resin 1 to form a mounting reinforcement portion.

More specifically, as shown in FIG. 2, a semiconductor element 4 and a die pad 5 supporting the semiconductor element 4 are provided.
Suspended lead 3 supporting die pad 5 at its tip
And a lead portion 2 having a tip portion disposed on a die pad portion 5.
To expose the thin metal wire 6 electrically connecting the lead portion 2 and the semiconductor element 4, the end portion 3 a of the suspension lead portion 3 and one side surface and the bottom surface of the lead portion 2,
This is a QFN type semiconductor device including a die pad portion 5 and a sealing resin 1 which seals the outer periphery of the fine metal wire 6. Further, the suspension lead portion 3 has a step portion (bent portion), and has a structure in which the die pad portion 5 is set up with respect to the lead portion 2. Therefore, the sealing resin 1 is present in the bottom region of the die pad portion 5 in a thickness corresponding to the upset. Also, the bottom surfaces of the end portions 3a of the lead portions 2 and the suspension lead portions 3 are projected and exposed from the surface of the sealing resin 1 with a slight protrusion amount of about 50 [μm].
In FIG. 2, the semiconductor element 4 is indicated by a broken line.

In order to mount the semiconductor device configured as described above on a mounting board such as a printed board, as shown in the cross-sectional view showing the mounting structure of FIG. The bottom surface and one side surface on the outside and the connection portions such as electrodes and wirings of the mounting substrate 7 are mounted using solder 8 of a bonding material. In this embodiment, as shown in FIG. 3 (b), the end 3a of the suspension lead 3 exposed at the end of each corner of the bottom surface of the semiconductor device and the connection points of the mounting board 7 such as electrodes and wiring are further formed. Is mounted using the solder 8. The width of the lead 2 of the semiconductor device of the present embodiment is 200 [μm], and the width of the suspension lead 3 and the end 3a is 180 [μm]. Therefore, the end portion 3a of the suspension lead 3 and the solder 8 can be joined, which can contribute to an improvement in mounting strength.

In the present embodiment, in addition to the structure in which the exposed bottom surface of the lead portion 2 disposed on the bottom surface of the semiconductor device and one outer side surface are joined to the mounting substrate by solder 8 and mounted, Exposed electrically unrelated suspension leads 3
The end 3a is also joined to the mounting board as a mounting reinforcement part, so that the number of joints increases, so that the mounting strength is dramatically improved and the influence of the stress applied depending on the use situation is eliminated. However, the reliability of the secondary mounting can be improved.

In particular, the exposed end 3a of the suspension lead 3
Are arranged at the ends of the respective corners of the bottom surface (mounting surface) of the semiconductor device, the mounting strength can be improved, and the mounting reliability can be improved by balancing the mounting balance. .

Further, in this embodiment, as shown in FIG. 1, each corner of the sealing resin 1 constituting the package is chamfered, and the end (end face) of the end 3a of the suspension lead 3 is formed. Although it is configured so as to be exposed at the chamfered portion, as shown in FIG. The (end face) may be exposed as a corner. In this case, since the end 3a of the suspension lead 3 approaches the corner of the package and can be mounted at the corner, the mounting strength can be further improved. Here, FIG. 4 is a diagram showing a semiconductor device mounted on a printed circuit board according to the present embodiment, wherein FIG. 4A is a plan view and FIG. 4B is a bottom view.

The method of mounting the semiconductor device according to the present embodiment is as follows. When the semiconductor device is mounted on a mounting board, one side surface and the bottom surface of the lead portion 3 of the semiconductor device are mounted with solder 8 as a bonding material. The end 3a of the suspension lead 3 exposed from the end of the bottom surface of the semiconductor device as a reinforcement is also mounted with solder 8, and is joined together in a solder reflow process.

As described above, in this embodiment, the QFN in which the lead portions are arranged on the bottom surface with the bottom surface and one outer side surface exposed.
Although the semiconductor device of the SON (Sma) type has been described as an example,
llOutline Non-leaded Pack
An age-type semiconductor device has the same effect of improving the mounting strength. Also, a semiconductor device of the type in which the die pad portion is exposed on the bottom surface has the same effect of improving the mounting strength. In other words, in the case of a semiconductor device in which the end of the suspension lead that is not electrically related to the bottom surface of the semiconductor device is exposed, in addition to the joining of the lead and the substrate, the end of the exposed suspension lead is Since it can be joined to the substrate, the mounting strength can be improved. In particular, when a semiconductor device is mounted on a miniaturized mobile phone in recent years, its use becomes severe, and stress due to bending or the like is applied to the mounting substrate, and even if stress is applied to the joint portion, the effect is eliminated. And the reliability of the secondary mounting can be improved.

[0027]

According to the semiconductor device mounting structure and the semiconductor device mounting method of the present invention, the exposed bottom surface of the lead portion disposed on the bottom surface of the semiconductor device and one outer side surface are joined to the mounting substrate by soldering. In addition to the structure to be mounted and mounted, the end of the electrically unrelated suspension lead exposed on the bottom surface is also bonded to the mounting board as a mounting reinforcement part and mounted, so the number of joints increases In addition, it is possible to remarkably improve the mounting strength, eliminate the influence of the applied stress depending on the use condition, and improve the reliability of the secondary mounting. Furthermore, in the case of a semiconductor device in which the end of the suspension lead portion that is not electrically related to the bottom surface of the semiconductor device is exposed, in addition to the joining of the lead portion and the substrate, the exposed end portion of the suspension lead portion Since it can be joined to the substrate, the mounting strength can be improved.

[Brief description of the drawings]

FIG. 1 is a view showing a semiconductor device having a mounting structure of a semiconductor device according to an embodiment of the present invention;

FIG. 2 is a view showing a semiconductor device having a semiconductor device mounting structure according to an embodiment of the present invention;

FIG. 3 is a sectional view showing a mounting structure of the semiconductor device according to the embodiment of the present invention;

FIG. 4 is a diagram showing a semiconductor device having a semiconductor device mounting structure according to an embodiment of the present invention;

FIG. 5 is a diagram showing a semiconductor device having a conventional semiconductor device mounting structure.

FIG. 6 is a diagram showing a semiconductor device having a conventional semiconductor device mounting structure.

FIG. 7 is a diagram showing a mounting structure of a conventional semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sealing resin 2 Lead part 3 Suspended lead part 3a Terminal part 4 Semiconductor element 5 Die pad part 6 Thin metal wire 7 Mounting board 8 Solder

Continued on the front page (72) Inventor Narishi Ota 1-1, Sachimachi, Takatsuki-shi, Osaka, Japan Matsushita Electronics Corporation (72) Inventor Masashi Funakoshi 1-1, Sachimachi, Takatsuki-shi, Osaka, Matsushita Electronics Corporation (72) Inventor Noboru Tani 1-1 Fukumachi, Takatsuki-shi, Osaka Matsushita Electronics Corporation F term (reference) 5F047 AA11 AB00 5F067 BB00 BD00

Claims (7)

[Claims] A lead portion for electrical connection on a bottom surface thereof;
A mounting structure of a semiconductor device in which a semiconductor device in which a terminal portion of a suspension lead supporting a die pad portion supporting a sealed semiconductor element is arranged is mounted on a mounting substrate, at least a bottom surface of the lead portion is provided. A mounting structure of a semiconductor device, wherein the mounting portion is mounted with a bonding material, and an end of the suspension lead portion exposed from a bottom surface of the semiconductor device as a mounting reinforcing portion is mounted with a bonding material. 2. A semiconductor device, a die pad portion supporting the semiconductor device, a suspension lead portion supporting the die pad portion at a distal end thereof, a lead portion having a distal end portion disposed on the die pad portion, and the lead. Connecting means for electrically connecting the portion and the semiconductor element, and exposing the end portion of the suspension lead portion and one side surface and the bottom surface of the lead portion,
The semiconductor device, the die pad portion, a mounting structure of a semiconductor device in which a semiconductor device made of a sealing resin that seals the outer periphery of the connection means is mounted on a mounting substrate, and one side surface and a bottom surface of the lead portion. Is mounted with a bonding material, and a terminal of a suspension lead portion exposed from an end of a bottom surface of the semiconductor device as a mounting reinforcing portion is mounted with a bonding material. 3. The mounting structure of a semiconductor device according to claim 1, wherein the bonding material is solder. 4. The mounting structure for a semiconductor device according to claim 1, wherein the mounting substrate is a printed circuit board. 5. A semiconductor device, a die pad portion supporting the semiconductor device, a suspension lead portion supporting the die pad portion at a tip end thereof, a lead portion having a tip end portion arranged on the die pad portion, and the lead Connecting means for electrically connecting the portion and the semiconductor element, and exposing the end portion of the suspension lead portion and one side surface and the bottom surface of the lead portion,
When mounting a semiconductor device comprising the semiconductor element, the die pad portion, and a sealing resin that seals an outer periphery of the connection means on a mounting board, one side surface and a bottom surface of the lead portion of the semiconductor device are bonded with a bonding material. And mounting at an end of a suspension lead portion exposed from an end of a bottom surface of the semiconductor device as a mounting reinforcing portion with the bonding material. 6. The method according to claim 5, wherein solder is used as the bonding material. 7. The method for mounting a semiconductor device according to claim 5, wherein the semiconductor device is mounted on a printed circuit board.