JPH08139136A - Terminal structure of film carrier - Google Patents

Abstract

PURPOSE: To obtain a terminal structure for film carrier in which a lead is protected against breakage through reinforcement while preventing solder touch surely. CONSTITUTION: A plurality of leads 2 are formed on a film base member. Holes 6a are made independently in the film base member between adjacent leads 2 on the outer lead side of the lead 2 and a part 1b of the film base material is bonded integrally onto the lead 2. The part 1b of the base material enhances the strength of the lead 2. The lead 2 is soldered 13 to the wiring pattern 12 on a board 11. The holes 6a prevents the solder 13 bulging from the lead 2 from touching the lead 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal structure of a film carrier for soldering a tape carrier package (TCP) or the like used in various electronic devices such as a calculator, an electronic notebook, a personal digital assistant, a word processor and a personal computer to a substrate. It is about.

[0002]

2. Description of the Related Art FIG. 15 is a sectional view showing a state in which a film carrier is soldered to a substrate in a conventional example, FIG. 16 is a plan view of the film carrier, and FIG. 17 is a plan view of FIG. 16 when the film carrier is soldered to a substrate. It is sectional drawing in the ee line. In the figure, 1 is a film base made of polyimide, 2 is a lead formed by etching a copper foil pattern on the film base 1, and 3 is a lead 2.
Of the semiconductor chip bonded to the inner lead of the above, 4 is a sealing resin for the semiconductor chip 3, 5 is an output terminal portion, and 6 is formed on the film base material 1 on the input terminal portion side (outer lead side) of the lead 2 so as to be elongated. Slits, 6a are holes existing independently of each other between the leads 2 adjacent to each other at a position facing the elongated slit 6, 11 is a substrate, 12
Is a wiring pattern made of copper foil formed on the substrate 11, 1
Reference numeral 3 is a solder that joins the outer lead of the lead 2 and the wiring pattern 12, and 31 is an OLB (outer lead bonding) bonding tool that presses in the portion of the elongated slit 6. The lead 2 itself has a thickness of 20
Since the thickness is very thin (μm), the base material 1a is left on the outermost end of the lead 2. The plurality of leads 2 arranged in the slit 6 are exposed.

FIG. 18 is a sectional view showing a conventional manufacturing process of a film carrier, and FIG. 19 is a flowchart thereof. First, the surface of the film substrate 1 (polyimide film) is coated with the adhesive 14 to cover the film 1.
5 are attached and the surface of the film substrate 1 is protected by the cover film 15. Next, after the film substrate 1 is cut into a tape having a predetermined width, slit punching is performed so that the film substrate 1 has the device holes 1
6, an elongated slit 6 for OLB (outer lead bonding) and a bending slit 17 are formed. The slit punch is punched with a die so that one elongated slit 6 is formed. Next, cover film 1
The copper foil 18 is laminated on the surface 5. Then, a photoresist 19 is coated on the copper foil 18, masked, baked into a pattern, and developed. Next, the device holes 16 and the slits 6 for OLB are coated with backing resins 20 and 21, and after etching, the resist and the backing resin are removed to form the leads 2 in a predetermined pattern. After that, a solder resist is applied, and plating such as tin plating is performed on the leads 2 to complete the film carrier.

[0004]

In the portion of the slit 6 where the lead 2 is soldered to the wiring pattern 12, the lead 2 is not covered with the film base material 1 and the lead 2 is exposed. Because T is
There is a problem that the lead 2 is disconnected at the boundary of the slit 6 when external stress (bending, twisting, shearing, etc.) is applied to both the CP alone and the soldered state to the substrate 11.

The elongated slit 6 is eliminated in order to reinforce the lead 2 so as not to be broken, as shown in FIGS. 20 is a cross-sectional view of the film carrier soldered to the substrate, FIG. 21 is a plan view of the film carrier, and FIG. 22 is a cross-sectional view taken along line ff of FIG. In this case, since the film base material 1 covers the whole of the lead 2, the strength of the lead 2 is not weakened and it is possible to prevent breakage of the lead. However, as shown in FIG. 22, there arises a problem of solder touch in which the solder 13 connects the adjacent leads 2 and the wiring patterns 12 to each other.

Since the OLB slit 6 was formed before the laminating of the wiring pattern 12 in the manufacturing process of the film carrier, the slit 6 is formed in advance when the lead 2 is formed by etching.
There is also a problem that the backing resin 21 has to be applied to the above, and the backing resin 21 must be removed after patterning, resulting in complicated manufacturing and high cost.

The present invention was devised in view of such circumstances, and an object thereof is to provide a film carrier terminal structure capable of reliably preventing disconnection of leads and solder touch.

[0008]

A terminal structure for a film carrier according to claim 1 of the present invention has a plurality of leads formed on a film base material, and the film base material is provided between adjacent leads on the outer lead side. Independent holes are formed in each of the holes, a part of the film base material is integrally bonded on each lead, and the leads are soldered to the pattern of the substrate. .

According to a second aspect of the present invention, there is provided a film carrier terminal structure according to the first aspect, wherein the width of the film base material on each lead is smaller than the lead width and both sides of the lead are exposed. It is characterized by being present.

In the film carrier terminal structure according to a third aspect of the present invention, a plurality of leads are formed on the film base material, and elongated slits are formed over all the leads on the outer lead side to face the elongated slits. Reinforcing resin is applied to each lead at the location.

[0011]

In the terminal structure of the film carrier according to claim 1, since a part of the film base material is integrally joined onto each lead, the lead is not exposed to external stress as compared with the conventional example in which the lead is exposed. Increases strength. Also,
The holes between the leads provide a space for the solder that protrudes between the leads to escape during soldering, thus avoiding solder touch.

In the film carrier terminal structure according to the second aspect of the invention, the solder protruding between the leads is absorbed so as to wrap around the exposed portions on both sides of the leads, and the solder touch can be prevented more reliably.

In the terminal structure of the film carrier of claim 3, since the reinforcing resin is integrated on each lead, the strength of the lead against external stress becomes higher than that of the conventional example in which the lead is exposed. . Further, the holes between the leads serve as spaces for the solder protruding between the leads to escape during soldering, so that solder touch can be avoided.

[0014]

Embodiments of the terminal structure of the film carrier according to the present invention will be described below in detail with reference to the drawings.

[First Embodiment] FIG. 1 is a cross-sectional view showing a state in which a film carrier is soldered to a substrate in the first embodiment, FIG. 2 is a plan view of the film carrier, and FIG. 3 is a film carrier soldered to the substrate. A- in the case of
It is sectional drawing in a line. A plurality of leads 2 are formed by etching a copper foil pattern on a film base material 1 made of polyimide, a semiconductor chip 3 is bonded to an inner lead of the lead 2, and the semiconductor chip 3 is sealed and bonded by a sealing resin 4. ing. Reference numeral 5 is an output terminal section. On the input terminal portion side (outer lead side) of the lead 2, instead of forming elongated slits over all the leads 2 as in the conventional example, only the independent holes 6a between the adjacent leads 2 are formed in the film substrate 1. Is forming. Therefore, the base material 1b having a thickness of 75 μm is integrally joined to the upper side of the lead 2 having a thickness of 20 μm, and the strength of the lead 2 against external stress is increased as compared with the conventional example in which the lead 2 is exposed. Between leads 2 and base material 1b
There are a plurality of holes 6a that are independent from each other. Such holes 6a can be formed by using a die for punching only between the leads 2 adjacent to each other and only the outer sides of the outermost leads 2 as well.

A wiring pattern 12 is formed on the substrate 11, and the substrate 11 and the film carrier having the above-mentioned structure are superposed on each other. At that time, the leads 2 and the wiring pattern 12 are soldered to each other in the outer lead portion. Are integrally joined using. Since the hole 6a exists between the adjacent leads 2, the solder 13 protruding from between the lead 2 and the wiring pattern 12 does not touch the adjacent soldered portion (solder touch prevention). Further, there is no need to apply the reinforcing resin after the film carrier is bonded to the substrate. When soldering, the OLB bonding tool 31 presses.

[Second Embodiment] FIG. 4 is a plan view of a film carrier according to a second embodiment, and FIG. 5 is a sectional view taken along line bb in FIG. 4 when the film carrier is soldered to a substrate. Compared with the first embodiment, the width of the base material 1b left on the lead 2 on the outer lead side is smaller than that of the lead 2. Both sides of the remaining base material 1b are located inside the end edges of the leads 2, and both side portions of the leads 2 are exposed. The root portion of the remaining base material 1b has the same width as the lead 2. Since other configurations are similar to those of the first embodiment, the same reference numerals are given to corresponding portions, and the description thereof will be omitted.

In the case of this embodiment, since the base material 1b is integrated with the lead 2 to increase the strength of the lead 2 against external stress and both sides of the lead 2 are exposed, the solder 13 is used. Remaining base material 1b
Since it absorbs so that it wraps around the exposed parts on both sides of, the solder touch can be prevented more reliably.

Further, it is not necessary to apply the reinforcing resin after the film carrier is bonded to the substrate.

[Third Embodiment] FIG. 6 is a sectional view showing a state in which a film carrier is soldered to a substrate in the third embodiment, FIG. 7 is a plan view of the film carrier, and FIG. 8 is a soldering method to the substrate. C- in FIG.
It is sectional drawing in the c line. In this embodiment, elongated slits 6 extending over all the leads 2 are formed on the film substrate 1 as in the conventional example, and polyimide is applied to each of the leads 2 facing the slits 6 in the solder resist coating process. A reinforcing resin 22 made of, for example, is applied to the width of the lead 2. A printing method is used as the coating method. The thickness of the reinforcing resin 22 is 2 as with the lead 2.
It is about 0 μm. Since other configurations are similar to those of the first embodiment, the same reference numerals are given to corresponding portions, and the description thereof will be omitted.

In the case of this embodiment, the strength of the lead 2 against external stress is increased as compared with the conventional example in which the lead 2 is exposed. Further, the presence of the holes 6a between the leads 2 can prevent solder touch. Further, the reinforcing resin 22
Is relatively thin at 20 μm, so it is an OLB for soldering.
The temperature of the bonding tool 31 may be the same as in the case of the conventional example in which the leads are exposed.

FIG. 9 shows the film carrier turned upside down,
The reinforcing resin 22 is applied from the side opposite to the case of FIG.

As is clear from the comparison between FIGS. 6 and 9,
Depending on whether the reinforcing resin 22 is applied to the front surface or the back surface of the film carrier, it is possible to freely solder either surface to the substrate 11.

[Fourth Embodiment] FIG. 10 is a plan view of a film carrier according to a fourth embodiment, and FIG. 11 is a sectional view taken along line d-d of FIG. 10 when the film carrier is soldered to a substrate. In this embodiment, the elongated slits 6 extending over all the leads 2 are formed on the film substrate 1 as in the conventional example.
And a reinforcing resin 22 made of polyimide or the like is applied to each of the plurality of leads 2 facing the slit 6 in a width smaller than that of the leads 2 in the solder resist applying step. Both sides of the reinforcing resin 22 are located inside the end edges of the leads 2, and the base portion of the reinforcing resin 22 has the same width as the leads 2. Since other configurations are similar to those of the first embodiment, the same reference numerals are given to corresponding portions, and the description thereof will be omitted.

In the case of this embodiment, the strength of the lead 2 against external stress is increased and both sides of the lead 2 are exposed, so that the solder 13 is made to wrap around both sides of the reinforcing resin 22. Absorbs and prevents solder touch even more reliably. Further, since the reinforcing resin 22 is thin, it is not necessary to raise the temperature of the OLB bonding tool so much during soldering.

[Fifth Embodiment] FIG. 12 is a sectional view showing a manufacturing process of a film carrier of a fifth embodiment, and FIG. 13 is a flowchart thereof. Compared with the case of the conventional example (FIGS. 18 and 19), the point that the elongated slit 6 is not formed in the outer lead portion when slit punching the film base material 1 is different (see FIG. 12C). Therefore, it is not necessary to coat the backing resin 21 when etching the copper foil. Then, after removing the resist for etching and the backing resin 20, an elongated slit 6 is punched in the outer lead portion (see FIG. 12 (f)). The other parts are the same as in the conventional example, and corresponding parts are designated by the same reference numerals. That is, 14 is an adhesive, 15 is a cover film, 16 is a device hole, 17 is a slit for bending, 18 is a copper foil, 19 is a photoresist, and 20 is a backing resin. Reference numeral 2 is a lead formed by etching the copper foil 18.

In the case of this embodiment, it is not necessary to coat the slit 6 with the backing resin 21 and to remove the backing resin 21.

[Sixth Embodiment] FIG. 14 is a sectional view showing a manufacturing process of a film carrier of a sixth embodiment. Unlike the fifth example, the device hole 16 is not formed when slit punching the film substrate 1 as in the conventional example (FIG. 19).
At the same time as the bending slit 17 and the bending slit 17, the elongated slit 6 is formed in the outer lead portion. And copper foil 18
Prior to the etching, the device hole 16 is coated with a backing resin 20, and the surface of the lead 2 in the slit 6 has the same width as the width of the lead 2 and the backing resin 21.
Coating. Since the portion of the lead width coated with the backing resin 21 is not etched, the film carrier is produced with the lead 2 coated with the backing resin 21. That is, backing resin 2
Leave 1 as it is.

Since the other construction is the same as that of the fifth embodiment, the corresponding portions are allotted with the same reference numerals and the description thereof will be omitted.

In the case of this embodiment, in the step of coating the backing resin 21, the backing resin 21 which also functions as a reinforcement for the leads 2 can be obtained, and it is necessary to apply the reinforcement resin after forming the leads 2 by patterning. There is no nature.

[0031]

According to the terminal structure of the film carrier of claim 1, since a part of the film base material is integrally bonded onto each lead, external stress is applied as compared with the conventional example in which the lead is exposed. It is possible to increase the strength of the lead to prevent the breakage of the lead, and the hole between the leads serves as a space for escape of the solder protruding between the leads at the time of soldering, so that solder touch between adjacent leads can be avoided.

According to the terminal structure of the film carrier of claim 2, since the width of the film base material on each lead is made smaller than the lead width and both side portions of the lead are exposed, the solder protruding between the leads can be removed. Since it absorbs by wrapping it around the exposed parts of both sides of the lead, it is possible to further prevent solder touch.

According to the terminal structure of the film carrier of claim 3, since the reinforcing resin is integrated on each lead,
Compared with the conventional example where the lead was bare, the strength of the lead against external stress can be increased and the disconnection can be prevented,
Further, the holes between the leads serve as spaces for escape of the solder protruding between the leads during soldering, so that solder touch can be avoided.

[Brief description of drawings]

FIG. 1 is a sectional view showing a state in which a film carrier is soldered to a substrate in a first embodiment of the present invention.

FIG. 2 is a plan view of the film carrier in FIG.

FIG. 3 is a cross-sectional view taken along the line aa in FIG. 2 when the film carrier is soldered to the substrate.

FIG. 4 is a plan view of a film carrier according to a second embodiment.

5 is a sectional view taken along line bb of FIG. 4 when the film carrier is soldered to the substrate.

FIG. 6 is a sectional view showing a state in which a film carrier is soldered to a substrate in the third embodiment.

FIG. 7 is a plan view of the film carrier shown in FIG.

8 is a sectional view taken along line cc of FIG. 7 when the film carrier is soldered to the substrate.

FIG. 9 is a sectional view corresponding to FIG. 6 of a modification of the third embodiment.

FIG. 10 is a plan view of a film carrier according to a fourth embodiment.

11 is a cross-sectional view taken along the line dd of FIG. 10 when the film carrier is soldered to the substrate.

FIG. 12 is a cross-sectional view showing the manufacturing process of the film carrier of the fifth embodiment.

FIG. 13 is a flowchart showing a manufacturing process in the case of the fifth embodiment.

FIG. 14 is a cross-sectional view showing the manufacturing process of the film carrier of the sixth embodiment.

FIG. 15 is a sectional view showing a state in which a film carrier is soldered to a substrate in a conventional example.

16 is a plan view of the film carrier in FIG.

17 is a sectional view taken along the line ee in FIG. 16 when the film carrier is soldered to the substrate.

FIG. 18 is a cross-sectional view showing a manufacturing process of a conventional film carrier.

FIG. 19 is a flowchart illustrating a manufacturing process of a conventional film carrier.

FIG. 20 is a sectional view showing a state in which a film carrier is soldered to a substrate in another conventional example.

21 is a plan view of the film carrier shown in FIG. 20. FIG.

22 is a cross-sectional view taken along line ff in FIG. 21 when the film carrier is soldered to the substrate.

[Explanation of symbols]

 1 ... Film base material 1b ... Base material left on the lead 2 ... Lead 3 ... Semiconductor chip 4 ... Sealing resin 5 ... Output terminal portion 6 ... Elongated slit 6a ... Hole 11 ... Substrate 12 Wiring pattern 13 Solder 14 Adhesive 15 Cover film 16 Device hole 17 Bending slit 18 Copper foil 19 Photoresist 20 Backing resin 21 Backing resin 22 ... Reinforcing resin 31 ... OLB bonding tool

Claims (3)

[Claims] 1. A plurality of leads are formed on a film base, and independent holes are formed in the film base between adjacent leads on the outer lead side to form a part of the film base on each lead. Are integrally joined,
A terminal structure of a film carrier, wherein the lead is soldered to a pattern of a substrate. 2. The terminal structure of the film carrier according to claim 1, wherein the width of the film base material on each lead is smaller than the lead width, and both side portions of the lead are exposed. 3. A plurality of leads are formed on a film base material, an elongated slit is formed over all the leads on the outer lead side, and a reinforcing resin is applied to each lead at a position facing the elongated slit. A film carrier terminal structure characterized by the above.