JPH08268488A - Lead frame packing structure - Google Patents

Abstract

PURPOSE: To prevent contact with a die pad part at the time of handling, the lowering of mold resin adhesion force caused by the adhesion of an oils and fats component and the lowering of the accuracy of a down set dimension. CONSTITUTION: Lead frames 11 are held from above and below by one sets of spacers 13 having holes 17 coinciding with the die pad parts of the lead frames 11. The holes 17 are closed from the outside by further holding the spacers 13 in an up-and-down direction by metal plates 19 and the lead frames 11 are packed along with the metal plates 19 by a sheet like packing material 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame packing structure used in a semiconductor device.

[0002]

2. Description of the Related Art Lead frames are used for handling 5
About 0 to 100 sheets may be stacked and packed. FIG. 5 is an exploded perspective view illustrating a conventional packing structure, and FIG.
FIG. 6 is a cross-sectional view of a conventional packaging structure. Spacers 3 for protecting the lead frames 1 are provided on the uppermost and lowermost surfaces of the leadframes 1 stacked with about 50 to 100 sheets, and the spacers 3 are made of pulp, resin, or the like as a raw material. The lead frame 1 is provided with a down set portion 5 in which the die pad is recessed one step lower than the surrounding inner lead portions in order to bring the height of the chip surface (not shown) close to the height of the inner leads and facilitate wire bonding. It For this reason, the spacer 3 is provided with a hole 7 for inserting and protecting the downset portion 5. In this way, the lead frame 1 whose upper and lower sides are sandwiched by the spacers 3 is further wrapped by a sheet-shaped packing material 9 made of polypropylene or the like on the outer side and packed.

[0003]

However, in the above-mentioned conventional packing structure, since the hole 7 into which the downset portion 5 is inserted is formed in the spacer 3, during the handling,
For example, if the hole 7 is held by hand, the packing material 9
Has contacted the back surface of the die pad, and there has been a problem that oil and fat components such as fatty acid ester adhered to the packaging material 9 adhere to the back surface of the die pad. Then, if the oil and fat component adheres to the back surface of the die pad, the adhesive force with the mold resin is reduced, which causes a package crack during reflow. Further, when the packing material 9 comes into contact with the back surface of the die pad, an external force may be applied to the die pad portion, which causes a problem in that an error occurs in the downset dimension. The present invention has been made in view of the above circumstances, and provides a lead frame packing structure capable of preventing the contact between the packing material and the back surface of the die pad during handling, prevention of reduction in mold resin adhesion, and downset dimensions. The purpose is to prevent the accuracy deterioration of.

[0004]

In order to achieve the above object, a lead frame packing structure according to the present invention has a set of spacers having a hole matching the die pad portion of the lead frame, and the lead frame is arranged in the upper surface direction and the lower surface direction. And the spacer is further sandwiched by a metal plate from above and below to close the hole from the outside, and the lead frame together with the metal plate is surrounded by a sheet-shaped packing material.

[0005]

In the lead frame packing structure described above, when the packed lead frame is handled, for example, when the hole portion of the spacer is held by the hand, the dent of the soft packing material into the hole is prevented by the hard metal plate. , The packing material will not contact the die pad through the hole.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the lead frame packing structure according to the present invention will be described in detail below with reference to the drawings. FIG.
FIG. 3 is a sectional view showing a first embodiment of the packaging structure of the present invention.
Lead frame 1 stacked with 50 to 100 sheets
A spacer 13 for protecting the lead frame 11 is provided on the uppermost surface and the lowermost surface of the spacer 1. The spacer 13 is made of, for example, pulp or resin as a raw material. The spacer 13 is provided with a hole 17 into which the downset portion 15 of the lead frame 11 is inserted, and the downset portion 15 is inserted into this hole 17 for protection. The spacers 13 provided on the uppermost surface and the lowermost surface of the lead frame 11 are further sandwiched by the upper and lower metal plates 19. Therefore, the hole 17 formed in the spacer 13 is closed from the outside by the metal plate 19. The lead frame 11, which is sandwiched between the upper and lower parts by the spacer 13 and the metal plate 19, is further wrapped and packed by a sheet-like packing material 21 made of polypropylene or the like on the outside.

In the packing structure according to this embodiment, when the hole 17 of the spacer 13 is held by a hand during handling, for example, the recess of the soft packing material 21 into the hole 17 is prevented by the hard metal plate 19. , Packing material 21 has hole 1
The down set portion 15 on the rear surface of the die pad is no longer in contact with the down set portion 15.

According to the packing structure of the first embodiment described above, since the metal plate 19 is further installed on the outer side of the spacer 13, the packing material 21 comes into contact with the downset portion 15 on the rear surface of the die pad through the hole 17. It is possible to prevent the fat component adhering to the packaging material 21 from adhering to the back surface of the die pad. Further, since the metal plate 19 protects the die pad portion, an external force is not applied to the die pad portion, and it is possible to prevent the downset dimension from being deformed due to the external force.

FIG. 2 is a sectional view showing a second embodiment of the packing structure of the present invention. In this embodiment, spacers 23 made of a hard material such as a metal or a resin material are provided on the uppermost surface and the lowermost surface of the lead frames 11 stacked with about 50 to 100 sheets. The spacer 23 has a recess 25 that covers the downset portion 15 of the lead frame 11.
Is formed, and the downset portion 15 is disposed and protected in the recess 25. Therefore, the recess 25 is formed to have a depth at least equal to or greater than the recess of the downset portion 15. In this way, the lead frame 11 whose upper and lower sides are sandwiched by the spacers 23 is further wrapped on the outer side by the above-mentioned packaging material 21 and packaged.

In the packing structure according to this embodiment, the downset portion 15 of the lead frame 11 has a hard spacer 23.
The packaging material 21 is covered with the recessed portion 25 formed in the above, and during handling, for example, even if a portion corresponding to the downset portion 15 is held by the hand, the packaging material 21 does not come into contact with the downset portion 15 on the rear surface of the die pad.

According to the packing structure of the second embodiment described above, since the recess 25 covering the downset portion 15 is formed in the hard spacer 23, the packing material 21 is the downset portion 1.
5, it is possible to prevent the adhesion of the fat component and prevent the downset dimension from being misaligned as in the first embodiment, and further, the metal plate 19 of the first embodiment can be deleted. The number of packing members can be reduced.

FIG. 3 is a sectional view showing a third embodiment of the packing structure of the present invention. In this embodiment, about 50 to 100 lead frames 11, which are stacked, are housed in a box-shaped lower lid 31 having an open top surface. The lower lid 31 is a so-called hard case made of a hard material such as metal, polyvinyl chloride, or plastic. Also, the lower lid 3
In No. 1, the inner peripheral shape (width and depth) of the opening is formed to be substantially the same as the outer peripheral shape (width and depth) of the lead frame 11 so that the accommodated lead frame 11 does not shift in the stacking surface direction.

A pedestal 33 is provided on the inner bottom portion of the lower lid 31, and the pedestal 33 carries the portion of the lead frame 11 other than the downset portion 15. Further, the pedestal 33 is formed to have a height higher than at least the recess of the downset portion 15. In other words, the downset portion 15 is arranged between the pedestal 33 and the lower lid 3
1 is arranged so as to float from the inner bottom portion. Pedestal 33
A cushioning material 35 is provided on the upper surface of the above, and the cushioning material 35 protects the contact surface of the lead frame 11 to be mounted. The lower lid 31 is covered with an upper lid 37, and a cushioning material 39 for protecting the uppermost lead frame 11 is provided on the lower surface of the top plate of the upper lid 37.

In the packing structure according to this embodiment, the lead frame 11 is housed in the lower lid 31 having substantially the same shape, and the lower lid 3
While the movement of the lead frame 11 within 1 is restricted,
By placing the lead frame 11 on the pedestal 33, the downset portion 15 is in a state of floating between the pedestals 33 from the inner bottom portion of the lower lid 31. As a result, the downset portion 15 does not come into contact with the lower lid 31, and at the same time, the lower lid 31 prevents foreign matter from coming into contact with the downset portion 15.

According to the packaging structure of the third embodiment described above, the lower lid 31 is formed in substantially the same shape as the lead frame 11, and the pedestal 33 that protects the downset portion 15 in a floating state is attached to the lower lid 31. Since the back surface of the die pad and the lower lid 31 are not completely separated and contact with each other, it is possible to prevent the fat component from adhering and to prevent the downset dimension from deviating during handling. Further, since the hard case is used, the durability is improved and the packaging member can be reused.

FIG. 4 is a sectional view showing a fourth embodiment of the packing structure of the present invention. The packaging structure of this embodiment is basically the same as the packaging structure of the third embodiment, except that the pedestal 33 is used.
Is characterized in that it is slidably attached to the lower lid 41, and that the pedestal 33 is provided with a positioning pin 43. The positioning pin 43 is inserted into a positioning hole 45 provided in the guide rail of the lead frame 11, and regulates the movement of the lead frame 11 so that the lead frame 11 does not shift in the lower cover 41 in the stacking surface direction. Further, the positioning pin 43 is attached to the pedestal 33.
By being slidable through the lead frame 11, it is possible to accommodate lead frames 11 having different frame widths. In addition, the cushioning members 35 and 39 and the upper lid 37 are constructed in substantially the same manner as in the third embodiment. It should be noted that the cushion member 39 has a hole 47 into which the tip of the positioning pin 43 is inserted, and the positioning pin 43 and the cushion member 39 have a fitting structure, so that the lead frame 11 has the positioning pin 43.
Is prevented from coming off.

In the packing structure according to this embodiment, the positioning pin 43 is inserted into the positioning hole 45 of the lead frame 11, the movement of the lead frame 11 is restricted by the positioning pin 43, and the lead frame 11 is fixed in the lower lid 41. To be done. At the same time, since the lead frame 11 is placed on the pedestal 33, the downset portion 15 floats above the inner bottom portion of the lower lid 41, and the downset portion 15 does not contact the lower lid 41. Further, when the frame widths are different, the positioning pin 43 is slid to the desired positioning hole position together with the pedestal 33, and the positioning pin 43 can be inserted into the lead frames 11 having different frame widths.

According to the packing structure of the fourth embodiment described above, the pedestal 33 in the third embodiment is made slidable, and the locating pin 43 is provided on this pedestal 33. It becomes possible to accommodate, and it becomes possible to handle a large number of types of frame widths with one hard case, and it is possible to share the hard case.

In the above-mentioned first, second, third and fourth embodiments, the packing structure of the lead frame subjected to the downset process has been described, but the lead frame packing structure according to the present invention is Of course, it is also applicable to a lead frame which is not down set.

[0020]

As described in detail above, according to the lead frame packing structure of the present invention, since the metal plate is installed on the outer side of the spacer, the packing material comes into contact with the die pad part through the hole of the spacer. It is possible to prevent the fat component adhering to the packaging material from adhering to the die pad portion.
Also, since the die plate is protected by the metal plate,
External force will not be applied to the die pad part, and it is possible to prevent the downset dimension from changing due to external force. As a result, it is possible to prevent a decrease in mold resin adhesion and a decrease in accuracy of downset dimensions.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of a packaging structure of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the packaging structure of the present invention.

FIG. 3 is a sectional view showing a third embodiment of the packing structure of the present invention.

FIG. 4 is a sectional view showing a fourth embodiment of the packaging structure of the present invention.

FIG. 5 is an exploded perspective view illustrating a conventional packaging structure.

FIG. 6 is a sectional view of a conventional packaging structure.

[Explanation of symbols]

 11 Lead Frame 13, 23 Spacer 15 Downset Part 17 Hole 19 Metal Plate 21 Packing Material 25 Recesses 31, 41 Lower Lid 33 Pedestal 37 Upper Lid 43 Positioning Pin 45 Positioning Hole

Claims (4)

[Claims] 1. A pair of spacers having a hole matching the die pad portion of the lead frame sandwiches the lead frame from above and below, and the spacer is sandwiched from above and below by a metal plate to form the hole from the outside. A lead frame packing structure, wherein the lead frame is closed and the lead frame is surrounded by a sheet-like packing material together with the metal plate. 2. A lead frame is sandwiched from a top surface and a bottom surface by a pair of spacers made of a hard material in which a recess for covering a die pad portion of the lead frame is formed, and the lead frame is surrounded by a sheet-like packing material together with the spacer. Lead frame packing structure characterized by 3. A box-shaped lower lid having an open upper surface is formed of a hard material, and an inner peripheral shape of the lower lid is formed to be substantially the same as an outer peripheral shape of the lead frame. Is provided on the inner bottom portion of the lower lid, and the lead pad is floated from the inner bottom portion by placing the pedestal on the inner bottom portion of the lower lid. A lead frame packing structure, characterized in that a frame is housed in the lower lid and an upper lid is covered on the lower lid. 4. A box-shaped lower lid having an open upper surface is formed of a hard material, and a pedestal for carrying a portion other than the die pad portion of the lead frame is movably provided on the inner bottom portion of the lower lid, and is provided on the lead frame. Positioning pins inserted into the positioning holes are erected on the pedestal, the positioning pins are inserted into the positioning holes, and the lead pads are placed on the pedestal so that the die pad part floats from the inner bottom part. A lead frame packing structure, characterized in that a frame is housed in the lower lid and an upper lid is covered on the lower lid.