JPH0362935A - Mounting method for film carrier type semiconductor device - Google Patents

Abstract

PURPOSE:To mount a film carrier type semiconductor device on a printed board by a solder reflow method by temporarily tacking leads which are provided on a suspender supporting frame of a suspender supporting frame part to a printed board, and correcting the warping of a suspender. CONSTITUTION:A semiconductor chip part is separated from a film carrier tape, and tacking leads 8 and outer leads 6 are cut. Thereafter, both leads are molded. Solder paste is applied on bonding-pad parts 3 and tacking pads 7 beforehand on a printed board. A semiconductor chip 1 whose cutting and lead molding are finished is mounted on the printed board after the position alignment with the bonding pads 3 and the outer leads 6. The tacking leads 8 are bonded to the tacking leads pads 7 by solder 4. The warping of a suspender 2 is corrected by bonding the tacking leads 8 to a printed board beforehand. The outer leads 6 which are molded at the lower part than the tacking leads 8 are securely bonded to the bonding pads 3 by a solder reflow method.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for mounting a film carrier type semiconductor device on a printed circuit board.

[Prior Art] As shown in FIGS. 7 and 8, a conventional method for manufacturing a film carrier type semiconductor device includes a sprocket hole 41 for conveyance and positioning, and a device hole which is an opening into which a semiconductor chip 31 is inserted. 39, a metal foil such as copper is adhered onto an insulating film such as polyimide, and the metal foil is etched to form leads of a desired shape (inner lead 35, outer lead 36) and a pad 44 for electrical selection. Thus, a film carrier tape 40 is manufactured.

Further, bumps 46, which are metal protrusions, are formed on the electrode terminals of the semiconductor chip 31.

Next, the inner lead 3 of the film carrier tape 40
5 and the bumps 46 of the semiconductor chip 31 by inner lead bonding (hereinafter referred to as IL) using a thermocompression bonding method or a eutectic method.
(abbreviated as B)) Electrical selection and bias testing of the semiconductor chip 31 is carried out by bringing a contactor into contact with the electrical selection pad 44 while it is attached to a film carrier tape.

As a result, a film carrier type semiconductor device is completed.

Here, in order to prevent deformation of the leads 35 and 36, suspenders 32, which are insulating film frames, may be provided in advance on the film carrier tape 40. Further, in order to improve reliability and mechanical protection, resin sealing may be performed by potting resin 47 as shown in FIG. 9.

When mounting the film carrier type semiconductor device as described above on a printed circuit board, the outer leads 36 are cut to a desired length, and then, as shown in FIG. semiconductor chip 31
After fixing the outer leads 36 to the printed circuit board 50
Outer lead bonding (hereinafter abbreviated as OLB) is performed to the upper bonding pad 52.

These film carrier type semiconductor devices can be bonded in one process regardless of the number of leads, so the manufacturing process is quick, and since the film carrier tape 40 is used, the work can be easily automated. It has the following advantages.

Among the manufacturing processes of the conventional film carrier type semiconductor device described above, the OLB process is generally performed by applying pressure and heating to the leads using a pressure tool, similarly to the ILB process. The joining is carried out by Au-Au thermocompression bonding, Au-8n eutectic or brazing using solder, etc.

In contrast, general packages such as plastic packages and ceramic packages, as well as TFL TT
Components such as capacitors and capacitors are often mounted by solder brazing, and in recent years, it has become common to use solder reflow method.

That is, solder paste is applied onto the bonding pads of a printed circuit board using a printing method, etc., and then components such as semiconductor packages and resistors are aligned and temporarily bonded to the printed circuit board with adhesive, and then heated using an infrared heating furnace or hot air. The printed circuit board is placed in a heating furnace or heated steam tank, or the solder paste is melted by laser welding and the components are mounted. Mounting using such a solder reflow method has advantages such as being able to mount many components at the same time and facilitating automation.

[Problems to be Solved by the Invention] However, when applying a film carrier type semiconductor device to the solder reflow method, the suspender portion of the film carrier type semiconductor device is formed of an insulating film, so the suspender portion is easily warped. This causes variations in lead height.

As a result, the solder paste applied to the bonding pads of the printed circuit board does not come into contact with the leads, resulting in a disadvantage that the semiconductor device cannot be mounted.

In general, as the density of packaging is promoted, the pitch of semiconductor devices is shortened, but as a result, mounting using the solder reflow method becomes difficult. Currently 0,
A pitch of 65 to 1.0 mm is common, for example, Nikkei Electronics, December 12, 1988, issue 141.
As shown on pages 149 to 149, it is said that the limit is 0.4 to 0.5 mm. In other words, an insufficient amount of solder paste causes insufficient wetting, and an excessive amount of solder paste causes solder bridges. Therefore, it is necessary to accurately control the solder paste application pattern, and for this reason, it is difficult to accurately maintain the lead height. required. The control amount for lead height and flatness is 0.05 to 0. Although approximately 10 mm is required, in the case of a film carrier type semiconductor device, the amount of warpage increases as the suspender portion becomes larger due to multiple leads, etc., and warpage of several hundred μm or more often occurs.

Therefore, mounting a film carrier type semiconductor device inside a shell is often carried out by pressing the leads with a pressure tool to correct for variations in lead height due to warping, as described above, and it is not possible to use the solder reflow method. There aren't many. However, most components such as general packages, resistors, and capacitors can be mounted using the solder reflow method, and mounting only film carrier type semiconductor devices individually using a pressure tool is not suitable for current automated mounting lines. In addition to the lack of matching, there are drawbacks such as the need to install a dedicated device for film carrier type semiconductor devices.

The present invention has been made in view of such problems, and includes:
It is an object of the present invention to provide a method for mounting a film carrier type semiconductor device that can correct warpage of suspenders and that can be easily mounted using a solder reflow method.

[Means for Solving the Problems] A method for mounting a film carrier type semiconductor device according to the present invention includes a semiconductor element, a lead connected to the semiconductor element,
The suspenders that support the leads, a part of the suspender support frame, and the part including the leads provided on the suspender support frame are cut and separated from the film carrier tape to form the leads; The present invention is characterized by comprising the steps of bonding the leads of the film carrier type semiconductor device to bonding pads on the printed circuit board by a solder reflow method.

[Function] In the present invention, after the temporary attachment leads provided on the suspender support frame are bonded to predetermined positions on the printed circuit board, the leads of the film carrier type semiconductor device and the leads on the printed circuit board are bonded using the solder reflow method. Join the bonding pad. Therefore, the warping of the suspender part during solder reflow can be prevented by using the temporary lead.
A film carrier type semiconductor device can be easily mounted using a solder reflow method.

[Embodiments] Next, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a film carrier type semiconductor device mounted by a method according to a first embodiment of the present invention. Inner leads 5 are connected to electrodes of the semiconductor chip 1 by bonding.

Outer leads 6 extending from the inner leads 5 are bonded to bonding pads 3 on the printed circuit board by solder 4. The inner lead 5 and the outer lead 6 are supported by suspenders 2 made of an insulating film. A temporary attachment lead 8 is formed in a part of the corner of this suspender 2.
is similarly bonded to a lead pad 7 for temporary attachment on a printed circuit board by solder 4. In this temporary attachment, the suspenders 2 are pressed against the printed circuit board by the arms 8.

Next, a method of manufacturing the film carrier type semiconductor device having the above structure will be explained with reference to the plan view of FIG. 2 and the cross-sectional view of FIG. 3.

FIG. 2 shows a film carrier tape 10 used in an embodiment of the invention. As shown in FIG. 2, the sprocket hole 11 is similar to the conventional film carrier tape.
In addition to the device hole 9 and the OLB hole 15, a metal foil such as copper is bonded onto the insulating film in which the lead hole 12 for temporary attachment is formed, and an inner lead 5, which is a lead of a desired shape, is formed by etching or the like. A film carrier tape 10 on which outer leads 6, electrical sorting pads 14, and tacking leads 8 are formed is prepared.

Here, a lead hole 12 for temporary attachment is opened and provided in a suspender support frame 13 that supports the suspenders 2, and a lead 8 for temporary attachment is provided so as to straddle the lead hole 12 for temporary attachment. ing.

Next, the inner lead 5 of the film carrier tape 10
and the bumps 16 provided on the electrodes of the semiconductor chip 1 are bonded (ILB) L by thermocompression bonding or the several-item method, etc.
Resin sealing is performed with resin 17. In this embodiment, as shown in FIGS. 2 and 3, inner lead bonding is performed with the lead pattern surface of the film carrier tape 10 and the element forming surface of the semiconductor chip facing each other face down.

Next, a contactor of a test device is brought into contact with the electrical selection pad 14 to perform electrode selection, and a film carrier type semiconductor device is completed.

The film carrier type semiconductor device manufactured in this manner is mounted in the following manner. That is, as shown in the plan view of FIG. 4 and the cross-sectional view of FIG. 5, the outer leads 6 are formed at the same time as the film carrier type semiconductor device is cut and separated. As shown in FIG. 4, the cutting position is at the outer edge of the lead hole 12 and the OLB hole 15, where the temporary lead 8 and outer lead 6 are left. The semiconductor chip portion is separated from the film carrier tape 10 by cutting.

For temporary attachment, after cutting the lead 8 and the outer lead 6,
Both perform lead molding. Here, for temporary attachment, use lead 8.
The molding depth is made shallower than the molding depth of the outer lead 6. In this embodiment, as shown in FIG.
Although the lead is formed into a butt lead shape only downward, there are no particular restrictions on the shape of this molding.

Next, as shown in FIG. 1, the semiconductor chip 1, which has been cut and lead-formed, is placed on the printed circuit board on which the bonding pad portion 3 and the temporary attachment pad 7 are coated with solder paste. At the same time, the lead 8 for temporary attachment is joined to the lead pad 7 for temporary attachment by solder 4.

Here, when mounting a film carrier type semiconductor device, for face-down ILB, after temporarily fixing the resin 17 on the semiconductor chip 1 and the printed circuit board with adhesive etc., the leads 8 for temporary attachment are joined. However, for temporary attachment, connect the lead 8 to the bonding pad 3 with adhesive instead of solder 4.
It may be joined to. In this way, the temporary attachment is done using the lead 8.
By bonding the suspenders 2 to the printed circuit board in advance, the warpage of the suspenders 2 is corrected, and the outer leads 6, which are formed below the leads 8 for temporary attachment, are reliably bonded to the bonding pads 3.

Next, after temporarily fixing the other parts onto the printed circuit board with adhesive as in the past, either place them into a glue flow furnace such as an infrared heating furnace, hot air heating furnace, or heated steam tank, or use solder paste by laser welding, etc. The outer leads 6 and bonding pads 3 of the film carrier type semiconductor device are fixed and bonded using solder 4, and the mounting together with other components is completed. In this way, according to this embodiment, the film carrier type semiconductor device can be mounted on a printed circuit board together with other components by the solder reflow method.

FIG. 6 is a plan view showing a second embodiment method of the present invention. Components that are the same as in the method of the first embodiment are given the same reference numerals, and detailed explanation thereof will be omitted.

In this embodiment, the first suspender support frame 13 is not provided, and only the lead 8 for temporary attachment is provided, and this is used to mount a film carrier type semiconductor device in the same manner as in the first embodiment. It can be performed. In order to form the suspenders 2 without providing a suspender support frame in this way, a two-layer tape is used to manufacture the film carrier tape 2°. The two-layer tape is made by forming a thin Cu layer on a polyimide film by electroless plating without using an adhesive, and selectively forming Cu to a thickness of about 35 μm by electrolytic plating using a photoresist method, eliminating unnecessary Form the part thinly. Then, this unnecessary portion of Cu is removed by etching the entire surface to form a pattern for leads and the like.

Next, the polyimide film is selectively etched using a photoresist method to form holes such as the device hole 9 and the OLB hole 21, and a desired plating such as Au or Sn is applied to complete the process. Thereby, the suspenders 8 can be formed without a suspender support frame. In the conventional three-layer film carrier tape, first, sprocket holes,
Device holes, OLB holes, etc. are opened by punching, and another film with weak adhesive strength that can be easily peeled is adhered.

Next, only the suspender support frame is cut and removed by punching, and then, after adhering Cu foil to the opposite surface via an adhesive, the previous film is peeled off.

Next, the film carrier tape 20 having the suspenders 2 without the suspender support frame can be manufactured by selectively etching the Cu foil and forming a desired plating process in the same manner as in the conventional method.

In the case of the film carrier tape 20 that does not have a suspender support frame as described above, the size of the suspender support frame requires a width of approximately 0°5 to 1.0 mm in the shell for manufacturing purposes. In the film carrier tape, the suspender frame restricts the hole size for OLB, whereas in the tacking of the present invention, the lead 8 also serves as the suspender support frame, so the present invention has no effect on the hole size for OLB. There is an advantage that there is no

In the above-described embodiment, the suspenders 2 are fixed by providing the temporary attachment lead 8, but it is also possible to use a suspender support frame in a conventional film carrier tape as a substitute for the temporary attachment lead. In this case, the suspender support frame 4 of the conventional film carrier tape shown in FIG.
For temporary attachment, leave 2 in the same way as the lead, and use adhesive to connect it to the temporary lead pad on the printed circuit board, or use a pattern such as Cu plated on the suspender support frame in the same way as other leads. It can be mounted by leaving a part and joining it by soldering or the like. That is, there are no particular restrictions on the method of joining the suspender support frame or the temporary attachment lead in place of the suspender support frame.

In addition, as the number of leads increases, outer leads are added to office ladies.
If the hole for B becomes large and the warp cannot be corrected sufficiently by temporarily attaching the suspender support frame only to a part of the square corner as in the above example, temporary attaching to the middle part of the OLB hole is not recommended. It is also possible to add a suspender support frame for leads or temporary attachment. Therefore, there are no restrictions on the position or number of leads for this temporary attachment.

[Effects of the Invention] As explained above, the present invention provides a method for temporarily attaching the suspender support frame or the suspender support frame portion of a film carrier type semiconductor device to a printed circuit board to prevent warpage of the suspender. Because it is corrected, like other parts,
Further, the film carrier type semiconductor device can be mounted on a printed circuit board at the same time as other components by a solder reflow method.

[Brief explanation of drawings]

1 is a perspective view showing a mounted state of a film carrier type semiconductor device manufactured according to a first embodiment of the present invention; FIG.
5 to 5 are diagrams showing a method for mounting a film carrier type semiconductor device according to the first embodiment of the present invention, FIGS. 2 and 4 are plan views, and FIGS. 3 and 5 are sectional views. , FIG. 6 is a plan view showing a film carrier type semiconductor device mounted according to a second embodiment of the present invention, and FIGS. 7 to 10 are diagrams showing the mounting process of a conventional film carrier type semiconductor device. FIG. 7 is a plan view, and FIGS. 8 to 10 are sectional views. 1.31; semiconductor chip, 2.32; suspenders, 3,
52; Bonding pad, 4; Solder, 5.35; Inner lead, 6.38; Outer lead, 8; Lead for temporary attachment, 9, 39; Device hole, 10, 20.40
; Film carrier tape, 11.41; Sprocket hole, 12; Lead hole for temporary attachment, 13, 42; Suspender support frame

Claims (1)

[Claims] (1) Remove the semiconductor element, the leads connected to the semiconductor element, the suspenders that support the leads, a part of the suspender support frame, and the parts including the temporary attachment leads provided on the suspender support frame from the film carrier tape. A process of cutting and separating leads and forming them, a process of bonding the temporarily attached leads to predetermined positions on the printed circuit board, and a process of bonding the leads of the film carrier type semiconductor device and the bonding pads on the printed circuit board by a solder reflow method. A method for mounting a film carrier type semiconductor device, comprising the steps of: