JP2536435B2 - Semiconductor package lead molding method and apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor package lead forming method and apparatus for obtaining a surface mount type semiconductor package, and more particularly, to a surface mount type package by molding the external leads of the semiconductor package into a gull wing shape. The present invention relates to a semiconductor package lead forming method and device, which can obtain a semiconductor package.

[0002]

2. Description of the Related Art FIG. 3 is a manufacturing process diagram of a conventional surface mount semiconductor package.

As shown in FIG. 3A, the semiconductor element 109
Is mounted on the island portion 111 of the lead frame 110, and the electrode of the semiconductor element 109 and the inner lead portion 110a formed on the lead frame 110 are connected using a metal wire 112 as shown in FIG. 3B. To be done. Next, as shown in FIG. 3C, the semiconductor element 109 and the inner lead portion 110a are entirely made of epoxy resin 113.
It is covered with and hardened. After that, a step (not shown) of cutting the resin outflow preventing tie bar provided on the lead frame 110 and a step (not shown) of plating the external leads 114 are performed, and as shown in FIG. The lead 114 is molded.

Now, a method of molding the external lead 114 will be described.

FIG. 4 is a schematic view showing a method of molding the external leads 114 to obtain a conventional surface mount semiconductor package.

As shown in FIG. 4, the semiconductor package 11
The semiconductor encapsulating portion 101 of 0 is supplied to the groove portion 104a formed in the die 104, and the package holder 106 is pressed from above.
Is held fixed by. The die 104 is formed with a protrusion 104b that supports the root of the external lead 102 from the lower surface. Next, the punch 103 having an appropriate trajectory descends from the upper part of the outer lead 102, and the outer lead 10
By pressing and deforming 2 onto the upper surface of the die 104, the vicinity of the tip of the external lead 102 is formed into a gull wing shape. The above-described molding operation is collectively performed on all the external leads 102.

[0007]

However, in the above-described conventional lead forming method, when the semiconductor encapsulation portion 101 of the semiconductor package 110 is warped or twisted, the complanarity is deteriorated.

FIG. 5 shows the external lead 1 when it is twisted along the semiconductor encapsulation portion 101 of the semiconductor package 110.
It is a figure which shows the shaping | molding process of 02.

As shown in FIG. 5A, the semiconductor encapsulation portion 101 of the semiconductor package 110 which is warped or twisted is supplied to the groove portion 104a on the die 104, and the punch 103 is lowered as shown in FIG. 5B. Then, the lead forming is completed. Here, the semiconductor enclosure 1 of the semiconductor package 110
The warp and twist of No. 01 are straightened by the pressure during lead molding. Next, as shown in FIG. 5C, when the punch 103 rises and the pressure applied to the external lead 102 is released, the semiconductor encapsulation portion 1 of the semiconductor package 110 is removed.
The warp of No. 01 and the restoration of the twist deteriorate the complanarity of the lead tip.

The warp and twist of the semiconductor encapsulation portion of the semiconductor package that deteriorates the complanarity are caused by resin encapsulation after the resin encapsulation is performed due to the internal structure of the semiconductor encapsulation portion and the difference in the thickness between the upper and lower portions of the semiconductor encapsulation portion. It occurs when the resin temperature drops. This is because the amount of resin shrinkage differs due to the difference in resin capacity between the upper portion and the lower portion of the semiconductor encapsulation portion, and it is difficult to avoid this due to the structure of the semiconductor package.

The surface mount type semiconductor package is mounted on the surface of a printed wiring board or the like by soldering by a method such as infrared reflow. However, if the external leads have poor complanarity, the leads may float, resulting in poor soldering. appear.
Such defects lead to quality deterioration and cost increase in an automated line. In recent years, with an increase in package size, an increase in the number of leads, and a reduction in lead pitch, it has become important to improve coplanarity.

The present invention has been made in view of the above-mentioned conventional circumstances, and provides a semiconductor package lead forming method and apparatus for preventing deterioration of external lead complanarity during surface mount semiconductor package manufacturing. The purpose is to provide.

[0013]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a surface mount type semiconductor package by molding an external lead protruding from a semiconductor encapsulation portion encapsulating a semiconductor element into a gull wing shape. In the method of forming leads of a semiconductor package, the external leads protruding from the semiconductor encapsulation portion of the semiconductor package fixed and held at a predetermined position are prevented from twisting or warping of the semiconductor package.
It detects the position information of the vertical direction by, based on the position information
Depending on the amount of movement, one or several external leads can be used as the lead support part.
After being moved to the lower surface of the root of the , the lead support is formed into a gull-wing shape for each or every external lead with the lead support portion as a fulcrum.

In order to obtain a surface mount type semiconductor package by molding the external leads protruding from the semiconductor encapsulation portion encapsulating the semiconductor element into a gull wing shape,
In a lead molding device for a semiconductor package, the stage is fixed above the semiconductor encapsulation portion of the semiconductor package and is movable in a plane, and the external lead of the semiconductor package fixedly held by the stage is installed above the external stage. Twist or warp of the semiconductor package of the lead
Detecting means for detecting position information in the up-down direction by means of, and a transfer device based on the position information detected by the detecting means, which is installed below the root of the external lead so as to face the detecting means.
Move to the bottom position of one or several external leads by
It is characterized in that it has a moved lead supporting portion and a forming means for forming a lead into a gull wing shape for each one or every several external leads with the lead supporting portion as a fulcrum.

[0015]

In the present invention configured as described above, the vertical position information of the external lead protruding from the semiconductor enclosing portion of the semiconductor package fixedly held at a predetermined position is detected,
Even if the semiconductor encapsulation portion of the semiconductor package is warped or twisted, a fulcrum is formed at the time of molding the lead by moving and supporting the lead supporting portion on the lower surface of the root of one or several external leads according to the position information. There is no gap between the lead support and the external lead. Then, by performing lead molding in this state with the lead supporting portion as a fulcrum, the external lead is molded without straightening the semiconductor sealing portion by the pressure during lead molding. The warp and twist will not be restored. Therefore, it is possible to prevent the deterioration of the planarity of the lead tip due to the restoration of the warp and the twist of the semiconductor sealing portion.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a view showing a first embodiment of an apparatus for suitably carrying out the method of forming leads of a semiconductor package of the present invention. FIG. 1 (a) is a schematic side view showing a state of lead forming,
(B) is a schematic perspective view.

As shown in FIG. 1, a lead forming apparatus for a semiconductor package for obtaining a surface-mounting type semiconductor package is a package as a stage in which a groove portion 2a for mounting a semiconductor enclosing portion 1 of a semiconductor package 10 is formed. It has a table 2. The package table 2 is connected to a drive motor (not shown), so that it can be driven in the X, Y, and θ directions in a plane. Above the package table 2, a package retainer 3 for fixing and holding the semiconductor enclosing portion 1 of the semiconductor package 10 is provided. Above the outer leads 4 of the semiconductor package 10 protruding in the horizontal direction from the package table 2, a sensor 6 is installed as a detection means for detecting the vertical position information of the outer leads 4. In the vicinity of the outer end surface of the package table 2 and at a position facing the sensor 6 with the external lead 4 sandwiched therebetween, a lead support base 5 that supports the root of the external lead 4 from the lower surface is vertically movable. A vertical drive motor 7 is attached to the lead support base 5, and the vertical drive motor 7 operates the lead support base 5 to the external lead lower surface position according to the position information detected by the sensor 6. . A die 8 is provided at a position adjacent to the lead support 5, and a punch 9 having a predetermined locus is provided above the die 8. The tip of the external lead 4 is formed by a molding means including the die 8 and the punch 9. In the vicinity, the lead support 5 is used as a fulcrum to form a lead in a gull wing shape.

Next, a method of forming the external lead based on the above apparatus will be described.

First, the semiconductor enclosing portion 1 of the semiconductor package 10 is supplied to the groove 2a of the package table 2 and fixed by the package retainer 3. At this time, the lead support base 5 is descending, and an arbitrary external lead 4 is placed on top of it.
Is located. When it is confirmed that the semiconductor package 1 has been set, the external leads 4 on the lead support base 5 are confirmed.
Is detected by the sensor 6 provided above the lead, and the amount of variation from the reference position (the position of the external lead 4 when the semiconductor encapsulation portion 1 is not warped or twisted) is calculated.

Then, the vertical drive motor 7 is driven in accordance with the variation amount, and the lead support base 5 is raised to a position in contact with the lower surface of the external lead 4.

Then, the tip of the outer lead 2 is pushed by the punch 9 from above the lead. The operation of the punch 9 has an appropriate locus, and after the outer lead 4 contacts the die 8 and is further pushed, the outer lead 2 is formed in a gull wing shape. The package table 5 is connected to the vertical drive motor 7 and is movable in the X, Y, and θ directions within a plane, so that when the lead formation of one external lead 4 is completed, the external table to be molded next is formed. The package table 2 moves so that the leads 4 are located on the lead support 5. The moving operation at this time is performed in a state where the lead support base 5 is lowered. In this way, lead forming for all external leads is completed.

In the above-described embodiment, lead molding is performed for each external lead, but it is also possible to collectively form several external leads.

FIG. 2 is a diagram showing a second embodiment in which two external leads are lead-formed at one time.

The lead support base 5a shown in FIG. 2 supports two external leads 4 at a time, and the molding operation by the lead support base 5a is the same as in the first embodiment described above. In this embodiment, there is an effect that the processing capacity for lead molding is improved.

[0026]

As described above, according to the present invention, the position information in the vertical direction of the external lead protruding from the semiconductor enclosing portion of the semiconductor package fixedly held at a predetermined position is detected, and the external information is detected according to the position information. Since a supporting part is moved and supported on the lower surface of the root of one lead or several leads, and a method and an apparatus for forming a lead into a gull wing shape for each external lead or for every several leads with the supporting part as a fulcrum, It is possible to prevent deterioration of coplanarity that occurs during lead molding of a semiconductor package having a twist along the semiconductor encapsulation portion. That is, by performing the lead forming with one or several leads, the forming pressure is reduced, and the package is not flattened and its restoration does not occur. Further, since it is possible to form the lead by eliminating the gap between the lead support and the lead, there is an effect that all the leads can be formed under a certain condition.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of an apparatus for suitably implementing the semiconductor package lead forming method of the present invention,
(A) is a schematic side view showing a state of lead molding, and (b) is a schematic perspective view.

FIG. 2 is a diagram showing a second embodiment in which two external leads are lead-formed at one time.

FIG. 3 is a manufacturing process diagram of a conventional surface mount semiconductor package.

FIG. 4 is a schematic diagram showing a method of molding external leads for obtaining a conventional surface mount semiconductor package.

FIG. 5 is a diagram showing a molding process of the external lead when there is a twist along the semiconductor enclosing portion of the semiconductor package.

[Explanation of symbols]

 1 Semiconductor Enclosure 2 Package Table 2a Groove 3 Package Presser 4 External Leads 5, 5a Lead Support 6 Sensor 7 Vertical Drive Motor 8 Die 9 Punch 10 Semiconductor Package

Claims (2)

(57) [Claims] 1. A method of forming a lead of a semiconductor package for obtaining a surface mounting type semiconductor package by forming an external lead projecting from a semiconductor encapsulation portion for encapsulating a semiconductor element into a gull wing shape, which is fixedly held at a predetermined position. External leads protruding from the semiconductor encapsulation portion of the semiconductor package
Vertical position information due to twisting or warping is detected, and the lead support portion is moved to the external lead by the amount of movement based on the position information.
A lead forming method for a semiconductor package, comprising moving one or several bottom surfaces of the roots , and then forming a gull-wing lead for each or every one of the external leads with the lead support portion as a fulcrum. 2. A semiconductor package lead molding apparatus for obtaining a surface mount type semiconductor package by molding an external lead protruding from a semiconductor encapsulation portion encapsulating a semiconductor element into a gull wing shape. Hold the part fixed,
A stage movable in a plane, disposed above the outer leads of the semiconductor package is fixed and held on the stage, of the external leads, the semiconductor
A detection means for detecting position information in the vertical direction due to twisting or warping of the body package, and a detection means installed below the root of the external lead so as to face the detection means, and based on the position information detected by the detection means.
Depending on the amount of movement,
A lead supporting unit that is moved by means of a lead supporting unit, and a forming unit that forms a lead into a gull wing shape for each external lead or for every several external leads with the lead supporting unit as a fulcrum. .