JPH04320811A - Mold for transfer mold - Google Patents

Abstract

PURPOSE:To provide a mold for transfer mold capable of preventing the occurrence of flashes between leads at the time of conducting resin seal. CONSTITUTION:Among the end periphery of a cavity 14b in a lower mold 4, the parts being opposite to etching cross-sections of films 34 are formed to be inclined for coming into contact with the etching cross-sections of the films 34 during resin seal.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer mold mold for resin-sealing semiconductor elements and the like.

0002

[Prior art] TAB (Tape Automated
Bonding technology is one of the IC chip mounting technologies, and it is possible to form leads with a large number of pins and a narrow pitch compared to other mounting technologies. In addition, high-speed automatic bonding can be performed face-up. For this reason, TAB technology has attracted particular attention in recent years. Fig. 6 is a schematic plan view of a conventional upper mold, Fig. 7 is a schematic plan view of a conventional lower mold, and Fig. 8 is a state when TAB tape is sandwiched between the conventional upper mold and lower mold. FIG. The TAB tape shown in FIG. 8 has an IC chip 132 and a film carrier on which leads 136 are formed on a film 134. The IC chip 132 is connected to leads 136 via bumps (not shown). As the film carrier, a two-layer tape is used, that is, a tape having a structure in which copper foil is directly attached to the film 134 without using an adhesive.

[0003] The transfer molding die includes an upper die 2 and a lower die 104. The upper mold 2 and the lower mold 104 shown in FIG. 6 and FIG.
Gate 16a, 1 is an injection port for injecting into 14b.
16b are formed. Further, a pot 12 which is a resin supply port is formed in the upper mold 2.

Transfer molding is mainly used to seal the IC chip 132 with resin to protect it. In the transfer molding method, as shown in FIG.
In this method, the TAB tape carrying the mold 32 is sandwiched, and heated and melted resin is injected into the cavities 14a and 114b of the upper mold 2 and the lower mold 104 under pressure and solidified. This method has the advantage that if the molten resin is injected into the resin molding die at a low speed, it is possible to mass-produce products of a constant quality without impairing the characteristics of the IC chips or the like.

[0005]

[Problems to be Solved by the Invention] By the way, when using a two-layer tape as a film carrier, the film 13
4 is processed by etching to form punched parts 142, etc.,
The etched cross section of the film 134 has a slope. Therefore, when the IC chip 132 mounted on the TAB tape is encapsulated with resin using a transfer mold mold, the etched cross section of the film and the lower mold cannot be brought into close contact.
A gap 150 is created. Typically, resin can easily fit into gaps of 50 microns. Therefore, when resin is injected into the cavities 14a and 114b of the conventional mold shown in FIG. 8, the resin also flows between the leads through this gap 150, causing resin burrs. Therefore, when punching out the resin-sealed TAB tape, there is a problem that the leads may be deformed or broken due to the burrs.

The present invention has been made based on the above-mentioned circumstances, and an object of the present invention is to provide a transfer molding die that can prevent burrs from forming between leads during resin sealing. It is.

[0007]

[Means for Solving the Problems] To achieve the above object, the present invention provides a transfer mold die used when resin-sealing a semiconductor element bonded to the surface of a film. The present invention is characterized in that an edge of the resin injection chamber is formed so as to come into contact with the film when sealing the semiconductor element with resin.

[0008]

[Operation] According to the present invention, the edge of the resin injection chamber of the mold is shaped so that it comes into contact with the film when sealing the semiconductor element with the resin. When a semiconductor element mounted on a tape is sealed with a resin, the film and the edge of the mold can be brought into close contact with each other, and therefore the sealing resin can be prevented from leaking out between the leads.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. 1 to 3. 1 is a schematic plan view of a lower mold of a transfer mold mold according to a first embodiment of the present invention, FIG. 2 is a schematic plan view of a TAB tape, and FIG. 3 is a lower mold of the transfer mold mold shown in FIG. 1. FIG. 3 is a schematic cross-sectional view taken along the line A-A, showing the situation when the TAB tape is sandwiched between the tapes.

The TAB tape shown in FIG.
2, and a film carrier on which leads 36 are formed on a film (tape) 34. The IC chip 32 and leads 36 are placed on one side of the TAB tape (this side is
It is called the surface of AB tape or film. ). The film 34 has a device hole (formed below the IC chip 32 in FIG. 2) and two
Different types of punched portions 42, 44 are formed. The film 34 is made of polyimide, which has good heat resistance and stretch resistance. Further, the leads 36 are divided into four lead groups 36a, 36b, 36c, and 36d for each IC chip, and are drawn out in four directions (vertical, horizontal, and vertical directions in FIG. 2). The punched portion 42 is formed within the resin-sealed region surrounded by the dashed line L, and the punched portion 44 is formed outside the resin-sealed region.

[0011] A two-layer tape is used as the film carrier. That is, the copper foil is attached to the film 34 without using adhesive.
The structure is such that it is pasted directly on the . To manufacture the two-layer tape, first, copper foil and film 34 are bonded together, and leads 36 are formed by electrolytic plating using a photoresist pattern. Thereafter, the polyimide is wet-etched to form device holes and punched portions 42 and 44.

The transfer mold mold of the first embodiment includes an upper mold 2 that presses the front surface of the TAB tape from above (the upper mold in FIG. 6 described as conventional) and a lower mold that presses the back surface of the TAB tape from below. 4. As shown in FIG. 6, the upper mold 2 is formed with a pot 12 which is a resin supply port, a cavity 14a which is a resin injection chamber, and a gate 16a which is an injection port for injecting resin into the cavity 14a. Further, an ejector pin 18a for ejecting the resin molded product from the mold is provided.

Similarly, the lower mold 4 shown in FIG. 1 is also formed with a cavity 14b and a gate 16b, and is also provided with an ejector pin 18b. In addition, air vents 22 are formed in the lower mold 4 at three corners of the cavity 14b for exhausting air and gas inside the cavities 14a and 14b to the outside when resin is injected. The reason why only one pot is provided is that if the supply ports were provided at the top and bottom, when the resin entering from two directions merged, a seam would be created and a mark would be left behind after resin molding. . Furthermore, in this embodiment, the portion of the edge of the cavity 14b of the lower mold 4 that faces the etched cross section of the film 34 is inclined so as to come into contact with the etched cross section of the film 34 during resin sealing. It is formed. Incidentally, all edges of the lower mold may be formed to be inclined, but corner portions where the lead groups 36a, 36b, 36c, and 36d are not drawn out (portions where the punched portions 42 are not formed) As for the edge corresponding to , there is no need to consider resin leakage between the leads, so there is no need to make it slope.

Next, a procedure for sealing the IC chip 32 with resin will be explained. The area of the TAB tape to be resin-sealed is the area surrounded by the dashed line L shown in FIG. This one-dot chain line L is drawn along the edge of the punched portion 44. In the transfer molding method, first, a TAB tape is placed between the upper mold 2 and the lower mold 4, and the TA is applied to both molds.
Clamp the B tape. At this time, the edge of the cavity 14b of the lower mold 4 is formed to be inclined so as to come into contact with the etched cross section of the film 34 as shown in FIG. The edge of the cutout 44 and the edge of the cavity 14b of the lower mold 4 are in close contact. Next, the molten thermosetting resin is poured from the pot 12 into the cavities 14a and 1 through the gates 16a and 16b.
Press fit into 4b. Then, after holding the pressurized state for several minutes to advance curing, the ejector pin 18a,
By extruding 18b, the resin-molded TAB tape is removed from the mold, and the resin sealing work is completed. Note that when punching out the resin-sealed IC chip 32, the leads 36 are cut approximately at the middle of the punching portion 44.

In the transfer mold mold of the first embodiment, the edge of the cavity of the lower mold is formed to be inclined so as to come into contact with the etched cross section of the film, so when sealing with resin, this etched cross section and the edge of the cavity of the lower mold can be brought into close contact. Therefore, in the conventional transfer molding die, a gap was created between the etched cross section of the film and the edge of the lower die, but according to this embodiment, such a gap does not occur. Therefore, it is possible to prevent resin from flowing between the leads through such a gap.

As described above, by resin-sealing the IC chip using the transfer mold mold of the first embodiment, it is possible to prevent burrs from occurring between the leads as described above. With the TAB tape resin-sealed using the transfer molding die of the example, the leads will not be deformed or cut by burrs when punching out IC chips.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a schematic cross-sectional view showing the situation when a TAB tape is sandwiched using a transfer mold die according to a second embodiment of the present invention. Here, in the following second and third embodiments, components having the same functions as those in the first embodiment are given the same reference numerals, and detailed explanation thereof will be omitted. The difference between the transfer mold mold of the second embodiment and the first embodiment is that a film 3 is placed inside the inclined edge of the cavity 14b of the lower mold 4a.
The difference is that the step portion 24 is formed with a height slightly smaller than the thickness of No. 4.

In the second embodiment, during resin molding, a film is engaged with a stepped portion of the edge along the cavity of the lower mold. Therefore, when the mold is pressed, since the film is generally softer than the leads, the film bites between the leads, reducing the gap between the leads. Moreover, as in the first embodiment, the edge of the cavity of the lower mold is formed to be inclined to match the shape of the etched cross section of the film, so that the etched cross section of the film and the edge of the cavity of the lower mold are formed at an angle. can be brought into close contact. Therefore, during resin sealing, it is more difficult for the resin to enter between the leads than when using the transfer mold mold of the first embodiment, which more reliably prevents resin burrs from forming between the leads. be able to.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 5 is a schematic partial cross-sectional view showing the situation when a TAB tape is sandwiched using a transfer mold die according to a third embodiment of the present invention. The difference between the transfer mold mold of the third embodiment and that of the first embodiment is as follows.
The film 34 is placed on the edge of the cavity 14b of the lower mold 4b at a portion facing the etched cross section of the film 34.
A step portion 240 having a height slightly smaller than the thickness of the step portion 240 is formed, and a gold wire 50 is attached to a corner 240a of the step portion 240.

According to this embodiment, when sealing the TAB tape with resin, the gold wire 50 of the lower mold 4b is attached to the film 3.
Since it comes into contact with and presses the etched cross section of No. 4, it is possible to prevent the resin from leaking between the leads as in the first embodiment. Other functions and effects are the same as in the first embodiment. Note that resin or the like may be used as the filling member instead of the gold wire.

[0021]

As explained above, according to the present invention, the edge of the resin injection chamber of the mold is formed so as to come into contact with the film when resin-sealing the semiconductor element. When sealing semiconductor elements mounted on the tape with resin, the etched cross section of the tape can be brought into close contact with the mold, which prevents resin burrs from forming between the leads. It is possible to provide a transfer mold die that can prevent the lead from being deformed or cut due to burrs during each punching process.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view of a lower mold of a transfer mold according to a first embodiment of the present invention.

FIG. 2 is a schematic plan view of a TAB tape.

[Fig. 3] A-A showing the situation when the TAB tape is sandwiched using the lower mold of the transfer mold mold shown in Fig. 1.
It is a schematic sectional view taken in the direction of arrows.

FIG. 4 is a schematic cross-sectional view showing a TAB tape sandwiched between lower molds of a transfer molding mold according to a second embodiment of the present invention.

FIG. 5 is a schematic partial cross-sectional view showing a TAB tape sandwiched between the lower molds of a transfer molding mold according to a third embodiment of the present invention.

FIG. 6 is a schematic plan view of a conventional upper mold.

FIG. 7 is a schematic plan view of a conventional lower mold.

FIG. 8 is a schematic cross-sectional view showing a TAB tape sandwiched between a conventional upper mold and a lower mold.

[Explanation of symbols]

2 Upper mold 4 Lower mold 12 Pot 14 Cavity 16 Gate 18 Eject pin 22 Air vent 24 Step part 32 IC chip 34 Film 36 Lead 42, 44 Punching part

Claims (3)

[Claims] 1. In a transfer molding mold used for resin-sealing a semiconductor element bonded to the surface of a film, an edge of a resin injection chamber of the mold is used for resin-sealing the semiconductor element. A transfer molding mold, characterized in that the mold is formed so as to come into contact with the film. 2. The transfer mold die according to claim 1, wherein a portion of the edge facing the film is shaped to match the shape of the film. 3. The transfer mold mold according to claim 1, wherein a stepped portion is formed in a portion of the edge facing the film, and a filling member is attached to a corner of the stepped portion. .