JPH0793345B2 - Film carrier and molding method using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a long film carrier on which an IC chip is mounted, and an improvement of a molding method for molding the IC chip and a portion to be sealed in a required peripheral portion thereof. It is a thing.

[0002]

2. Description of the Related Art The degree of integration of IC chips tends to be increased due to the recent demand for multi-functionality. For this reason, the leads have been made to have an extremely high density and a large number of pins, and the products themselves have been made extremely small and thin for use in IC cards and the like.

A TAB method (tape automated bonding method) is known as an IC chip mounting technology capable of meeting these requirements. In this TAB method, a large number of leads are mounted on a carrier tape made of a polyimide resin film, and each inner lead and each surface electrode of an IC chip are connected via bumps. Based on No. 9, the structure of the film carrier obtained by this method will be described.

As shown in FIGS. 6 to 9, sprocket holes 2 for feeding the tape are formed at both edges of the polyimide resin film carrier tape 1. In addition, a rectangular mounting hole corresponding to the rectangular shape of the IC chip 3 is formed in the center of the carrier tape 1.
In addition, a rectangular support ring 5 is installed in the mounting hole via tie bars 4 provided at four corners of the hole. Also, in the support ring 5, I
A device hole 6 for fitting the C chip 3 is provided,
In addition, an outer lead hole 7 is provided on the outer periphery of the support ring 5 for mounting an outer lead.
A large number of leads 8 which are conductors are integrally mounted in the mounting holes of the IC chip 3 described above. Further, the inner leads 8 ₁ of the respective leads 8 project into the device holes 6 described above, and the outer leads 8 ₂ of the leads 8 are laid over the outer lead holes 7 described above. Test pads 8 ₃ are provided on the extended ends of the outer leads, respectively. The IC chip 3 is securely mounted on the carrier tape 1 by inner lead bonding for connecting the surface electrodes of the IC chip 3 to the inner leads 8 ₁ through the bumps 9. In addition, the IC chip 3 on the carrier tape 1 and its peripheral portion, that is, the sealed portion 10 of the film carrier set corresponding to the shape of both cavities of the molding die is transferred by means of a transfer molding method or the like. Molded,
Next, by cutting and separating from the outer lead 8 ₂ part, each outer lead of the product alone and each electrode of the printed wiring board can be connected by so-called outer lead bonding.

[0005]

By the way, in the case where the above-mentioned sealed portion of the carrier tape is molded by the transfer molding method, there are the following problems in resin molding.

In this molding method, first, a film carrier is supplied to a predetermined position of a mold (both upper and lower molds) to perform mold clamping, and then a resin material heated and melted in a pot of the mold is used. by pressure injecting into both the cavity through a transfer passage 11 consisting of the runner and the gate 11 _1, to be sealed portion 10 in the film carrier, in the mold package to be molded in correspondence to both said cavity portion shape It can be sealed (see reference numeral 10 in FIG. 7).

However, for example, the pitch p of the outer leads 8 ₂ is set to about 450 μm, and the pitch of the inner leads 8 ₁ is set to about 150 μm. Almost no molten resin material can pass through during molding. Therefore, as shown in the above-mentioned example, when the molten resin material R is injected into the upper mold cavity side, the injected resin material is filled into the upper surface side of the sealed portion 10 of the film carrier, so that the injected resin material is It acts so as to push (downward) the sealed portion 10 into the lower mold cavity. Thus, for example, electrically surface electrode and is come off the inner leads ₈₁ of the IC chip 3 connected, the IC chip 3 is exposed to the outside serious adverse effects such as the sealing is incomplete resulting It will be.

Further, in the above example, the molten resin material injected into the upper mold cavity side (the upper surface side of the sealed portion 10) is first filled in the upper mold cavity, and then the IC chip 3 and It will flow into and be filled in the lower mold cavity through a gap S or the like from the mounting hole. Therefore, in the lower mold cavity, a particularly large amount of unfilled resin occurs and a defect is formed on the surface of the mold package 12, and the molten resin material injected into the upper mold cavity has the above-mentioned gap. When flowing into the lower mold cavity through S, the support ring 5 and the IC chip 3
The remaining air is trapped on the back surface side of the and the voids (air bubbles) are formed in that portion. The formation of defects and internal voids in the mold package 12 as described above is a serious adverse effect of impairing the moisture resistance of the product and lacking reliability.

The sealed portion of the carrier tape
Mold the 10 by transfer molding method
Encapsulation within 12 has the following problems in resin molding. For example, when clamping both upper and lower molds,
As shown in FIG. 9, a space (usually about 35 μm) corresponding to the thickness t of the lead 8 and a space corresponding to each outer lead 8 ₂ are formed at the peripheral edge of the cavity on the (parting line) surface. Part, that is, the inner / outer communication portion 13 of the mold cavity is generated, so that the molten resin material injected into the mold cavity flows out of the inner / outer communication portion 13 into the outer lead hole 7, Penetration between the surfaces will form a resin burr. For this reason, a predetermined resin pressure cannot be applied to the molten resin material in the cavity, so that voids are formed inside and outside the mold package 12 to weaken its mechanical strength, or the void in the cavity due to insufficient amount of resin remains. A filled state occurs and reliable molding cannot be performed on the sealed portion. Further, the outflowing resin material adheres to each outer lead 8 ₂ and the connection between the outer lead and the electrode of the printed wiring board is poor. In addition to degrading the quality and reliability of this type of product, there are problems such as the need for a reliable cleaning process for the PL surfaces of both types.

According to the present invention, there are problems such as electrode detachment and incomplete sealing in the above-mentioned sealed parts during molding.
Alternatively, it is possible to improve the quality and reliability of this type of product by providing a film carrier capable of surely preventing the formation of a defective portion of the mold package or an internal void thereof and a molding method using the same. It is intended. The invention is disclosed in Japanese Patent Application No. 1-
The above-mentioned film carrier disclosed in the specification and drawings of No. 102095 and a molding method using the same are separately filed.

[0011]

A film carrier according to the present invention is a film carrier provided with a support ring for supporting a large number of leads in a hole for mounting an IC chip via a tie bar, wherein the tie bar portion is molded. It is characterized in that a required through hole communicating with both cavity parts in the mold is formed.

Further, the film carrier according to the present invention is
It is characterized in that at least one tie bar portion is formed with a through hole for a resin passage which communicates with a resin passage portion in a molding die.

Further, the film carrier according to the present invention is
The above-mentioned at least one tie bar portion is characterized in that a through hole for air vent which communicates with both cavities of the molding die is formed.

Also, in the molding method using the film carrier according to the present invention, the film carrier provided with the support ring for supporting a large number of leads in the IC chip mounting hole is set at a predetermined position in the molding die. A step of setting the film carrier, a step of clamping the die in a state where both sides of the support ring in the film carrier and both cavities of the die are joined, and a molten resin for sealing A molding method using a film carrier, comprising a step of injecting a molten resin material from a resin passage portion of a molding die into a cavity, wherein the step of injecting the molten resin material is the resin passage of the molding die. Through hole in which at least one tie bar portion is provided with a portion of the molten resin material injected from the section Through by injecting into the cavity, it is characterized in that a molten resin material injected is intended to substantially simultaneously charged into the two cavities in the mold.

Further, in the molding method using the film carrier according to the present invention, in the above-mentioned step of injecting the molten resin material, the air in both cavities is discharged to the outside through the through hole formed in at least one tie bar portion. It is characterized by.

[0016]

According to the present invention, at the time of molding, the molten resin material injected into the cavities is passed through the resin passage through holes formed in the tie bar portion of the film carrier to both cavity sides thereof, that is, the film. The carrier can be injected and filled almost simultaneously and smoothly on both front and back surfaces of the sealed portion. Further, according to the present invention, at the time of molding, the residual air in the cavity can be discharged to the outside through the through hole for air vent formed in the tie bar portion of the film carrier.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the embodiment diagrams shown in FIGS. 1 and 2 show the essential parts of the film carrier according to the present invention, the basic structure of which is the same as the conventional one shown in FIGS. 6 to 9. Further, FIGS. 3 to 5 show a state in which the film carrier according to the present invention is set at a predetermined position of a molding die.

That is, sprocket holes for feeding the tape are formed at both edges of the carrier tape 21, and
A mounting hole for the IC chip 23 (see FIG. 4 etc.) is formed in the center of the carrier tape. Further, a support ring 25 is installed in the mounting hole via a tie bar 24, and a device hole 26 for fitting the IC chip 23 therein is provided in the support ring 25, and the support is provided. An outer lead hole 27 is provided on the outer periphery of the ring 25 for installing an outer lead.

Further, the mounting hole portion of the IC chip 23, as shown in FIG. 1, along with a number of leads 28 which is a conductor is integrally mounted, the inner leads 28 ₁ in the respective lead 28 is the Each of the device holes 26 is projected.

The outer lead 28 ₂ of each lead 28 is provided on the outer lead hole 27 described above, and a test pad 28 ₃ is provided at the extended end of each outer lead. .

Further, the IC chip 23 is formed by inner lead bonding for connecting the surface electrode and each inner lead 28 ₁ through the bump 29 (see FIG. 4 etc.).
It is securely mounted on the carrier tape 21.

Further, required small piece portions 25 ₁ are projectingly provided between the leads 28 (outer leads 28 _{2 in the} illustrated example) of the support ring 25, and these small piece portions are When the mold dies are clamped, they are respectively extended to the positions where they are joined to the peripheral edge of the mold cavity 30.

Further, among the tie bars 24, at least one tie bar 24 ₁ corresponding to the position of the gate 11 ₁ of the mold.
A gate hole 24 ₃ (a through hole for a resin passage) that vertically penetrates is formed in the portion. In addition, the gate hole 24
_As shown in FIGS. 1 to ₃ , ₃ is provided so as to vertically penetrate the portion of the tie bar 24 ₁ and to communicate with both the cavities 30 of the molding die (see FIG. 3). Therefore, the molten resin material is pressurized transfer through a die gate 11 ₁ described above R, together can be substantially simultaneously respectively flow into both cavities 30 of the upper and lower from the gate hole 24 _3, the both cavities 30 It can be filled smoothly inside. Therefore, even if the molten resin material R is injected from the upper mold cavity side, the injected resin material does not bend the sealed portion 20 of the film carrier into the lower mold cavity. Incidentally, contrary to the case of the above example,
Even when the molten resin material R is injected from the lower mold cavity side, it is possible to reliably prevent the injected resin material from pushing up the sealed portion 20 of the film carrier into the upper mold cavity.

Further, at least one or all of the tie bars 24 ₁ other than the tie bar 24 ₁ portion having the above-mentioned gate hole 24 ₃ are vertically penetrated, and
Air vent holes 24 ₄ (through holes for air vents) communicating with the upper and lower cavities 30 are provided (see FIG. 2).
Therefore, in combination with the action of injecting and filling the molten resin material R in both cavities 30, the air in both cavities 30 can be efficiently discharged to the outside through the air vent holes, so that the air in both cavities 30 can be efficiently discharged. It is possible to reliably prevent the formation of voids in the mold package 12 due to the discharging action. Further, at the time of injecting the molten resin material R into both the cavities 30, it is possible to efficiently and reliably perform the inflow filling action and the air exhaust action without bending the sealed portion 20 of the film carrier. The adhesiveness between the mold package and each tie bar and support ring portion can be increased by the resin material filled and solidified in each through hole described above after molding.

In the film carrier having the above structure, the IC chip 23 of the carrier tape 21 and its required peripheral portion (sealed portion 20) are formed into the shapes of both cavities 30 of the mold by means such as a transfer molding method. By encapsulating it in a correspondingly molded mold package 12 and then cutting and separating it from the outer lead 28 ₂ part, outer lead bonding of each product and each electrode of the printed wiring board is carried out. Can be connected to each other.

As described above, the film carrier has a small piece portion 25 ₁ extending between the leads 28 of the support ring 25 and a joining position with the peripheral edge of the mold cavity during mold clamping. Are projected respectively.
Therefore, according to the configuration of such an embodiment, the following remarkable effects can be obtained. That is, first, the film carrier is a mold cavity in the mold open state.
It is supplied to a predetermined position of 30 parts, and then the intermediate mold clamping (see FIG. 4) and its complete clamping (see FIGS. 3 and 5).
Is performed. However, in the process from the middle mold clamping to the complete mold clamping of this mold, the support ring
Since each small piece portion 25 ₁ in 25 receives mold clamping pressure via the peripheral edge of the mold cavity 30, each small piece portion 25 ₁
While being deformed or crushed between the PL surfaces (see FIG. 5), the deformed or crushed small pieces are positioned between the leads 28 (outer leads 28 ₂ ) described above, that is, inside and outside the mold cavity. The communication parts 13 (see FIG. 9) are closely fitted to each other. For this reason, the peripheral edge of the cavity 30 in the molding die is
Since it is substantially sealed by the small pieces that are tightly fitted to the positions between them, in this state, by molding by means such as a transfer molding method,
The resin leakage from the peripheral portion of the mold cavity 30 can be efficiently and surely prevented.

The present invention is not limited to the above-mentioned embodiment drawings, and the configuration and method arbitrarily and appropriately changed / selected as necessary without departing from the spirit of the present invention. Can be adopted.

For example, in the embodiments, the case where the molding means by the transfer molding method is adopted has been described, but it is obvious that the present invention can be applied to the molding by the usual injection molding method.

The film carrier has a structure of a three-layer tape in which a carrier tape made of a polyimide resin film and a conductor lead (copper foil) are adhered with an adhesive, or the carrier tape and the lead are adhered to each other. Any two-layer tape structure that does not use an adhesive may be employed.

[0030]

According to the present invention, at the time of molding, the molten resin material injected into the cavity is substantially simultaneously applied to the front and back sides of the sealed portion of the film carrier.
Moreover, since the smooth filling and filling can be performed and the residual air in both cavities can be efficiently discharged to the outside, there is a problem such as the electrode detachment or incomplete sealing of the sealed parts during molding, or There is an excellent effect that a film carrier capable of efficiently and reliably preventing the formation of a defective portion of the mold package or an internal void thereof and a molding method using the film carrier can be provided.

Further, by using the present invention, an excellent practical effect that this kind of product having high quality and high reliability can be molded is exhibited.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing a main part of a film carrier according to the present invention.

FIG. 2 is a partially cutaway perspective view showing a positional relationship between a main part of the film carrier of FIG. 1 and a resin passage in a molding die.

FIG. 3 is a partially cutaway vertical sectional view of a main part taken along the line AA of FIG.

FIG. 4 is a partially cutaway vertical sectional view showing a state in which the film carrier according to the present invention is set in a molding die, showing an intermediate clamping state of the die.

5 is a partially cutaway vertical sectional view corresponding to FIG. 4, showing a complete mold clamping state of the mold.

FIG. 6 is a plan view showing a main part of a conventional film carrier.

7 is a vertical cross-sectional end view of the main part taken along the line BB of FIG.

8 is a partially cutaway perspective view of the film carrier corresponding to FIG.

FIG. 9 is a partially cutaway schematic perspective view of a main part of a film carrier for explaining a conventional problem at the time of molding.

[Explanation of symbols]

11 ₁ Mold gate 12 Mold package 20 Encapsulation part 21 Carrier tape 23 IC chip 24 Tie bar 24 ₁ Tie bar 24 ₃ Gate hole 24 ₄ Air vent hole 25 Support ring 25 ₁ Small piece part 26 Device hole 27 Outer lead hole 28 Lead 28 ₁ Inner lead 28 ₂ Outer lead 28 ₃ Test pad 29 Bump 30 Mold cavity R Molten resin material S Gap

Claims (5)

[Claims] 1. A film carrier provided with a support ring for supporting a large number of leads through IC tie mounting holes through a tie bar, wherein the tie bar portion has a required penetration for communicating with both cavities of a molding die. A film carrier characterized by being formed by forming holes. 2. The film carrier according to claim 1, wherein at least one tie bar portion is formed with a through hole for a resin passage which communicates with a resin passage portion in the molding die. 3. The film carrier according to claim 1, wherein at least one tie bar portion is provided with a through hole for air vent which communicates with both cavities of the molding die. 4. A film carrier setting step of setting a film carrier having a support ring for supporting a large number of leads through IC chip mounting holes through tie bars at a predetermined position in a molding die, and in the film carrier. A mold clamping step of clamping the mold with both surfaces of the support ring bonded to both cavities of the mold, and a molten resin material for sealing from the resin passage of the mold into the cavity. A method of molding using a film carrier, which comprises a step of injecting a molten resin material into a mold, in which the step of injecting the molten resin material described above comprises Melt injected by injecting into the cavity through a through hole drilled in at least one tie bar A molding method using a film carrier, characterized in that a resin material is filled substantially simultaneously in both cavities of a molding die. 5. The film carrier according to claim 4, wherein in the step of injecting the molten resin material, the air in both cavities is discharged to the outside through a through hole formed in at least one tie bar portion. Molding method.