JPH0653395A - Package and manufacture thereof - Google Patents

Abstract

PURPOSE:To facilitate alignment of outer leads in the case of mounting the leads and to prevent deformation of the leads at the time of mounting and after mounting. CONSTITUTION:A package comprises guide leads 2a-2f outside arranged outer leads 1a-1c and fixed to sides of package bases 3, 5. A method for manufacturing the package comprises the steps of bringing the leads 1a-1c of a lead frame 7 having the arranged leads 1a-1c and the leads 2a-2f bent at ends down outside the leads 1a-1c into contact with upper surfaces of the bases 3 when the outer leads are attached to the bases 3, 5, 5 through a brazing material 6, bringing the leads 2a-2f into contact with the sides of the bases 3, 5 through the material 6, and brazing them.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a package and a manufacturing method thereof. In recent years, along with the high integration of semiconductor devices, flat packages (QF
P) has become popular. The outer leads tend to have a narrower pitch, making accurate positioning difficult when mounting the outer leads. Furthermore, the outer leads are becoming thinner and the outermost outer leads are particularly susceptible to deformation. .

[0002]

2. Description of the Related Art FIG. 3 is a plan view and a sectional view showing a conventional example of a flat package. (A) is a plan view, (b) is a sectional view taken along line AA, 1a to 1c are external leads, and 3 is Ceramic substrate,
4 is a cavity, 5 is a metal film, 6 is a brazing material, and 7 is a lead frame.

A lead frame 7 having a large number of external leads 1a to 1c arranged inside is aligned with the metal film 5 on the ceramic substrate 3 and brazed with a brazing material 6, and then the lead frame 7 is placed at a position indicated by a dotted line. External leads 1a to 1c are formed on the upper surface of the ceramic substrate 3 by cutting. Although not shown, after that, a chip is mounted in the cavity 4, the bonding pad on the peripheral portion of the chip and the metal film 5 are connected by a bonding wire, and the chip is sealed by a seal frame and a cap.

By the way, when the lead frame 7 is supplied onto the ceramic substrate 3 by an automatic machine, a positional deviation is likely to occur. Further, as the pitch becomes narrower, the width of the external leads 1a to 1c has become narrower, which causes a problem that the outer leads arranged on the outermost side are particularly easily deformed.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a package having a structure that facilitates alignment when attaching external leads and prevents deformation of the external leads during and after attachment. The purpose is to Moreover, it aims at providing the manufacturing method which implement | achieves the structure.

[0006]

FIG. 1 is a plan view showing an embodiment, and FIGS. 2 (a) to 2 (c) are a sectional view and a perspective view showing the embodiment.

The above-mentioned problem is solved by the arranged external leads 1a to 1c.
A package having guide leads 2a to 2f on the outer side of the package, the guide leads 2a to 2f being solved by a package fixed to the side surfaces of the package bases 3 and 5.

Further, when attaching the external leads to the package bases 3 and 5, leads having arranged external leads 1a to 1c and guide leads 2a to 2f whose tips are bent downward outside the external leads 1a to 1c The outer leads 1a to 1c of the frame 7 are brought into contact with the upper surfaces of the package bases 3 and 5 via the brazing material 6, and the guide leads 2a to 2f are brought into contact with the side faces of the package bases 3 and 5 via the brazing material 6. It is solved by the manufacturing method of the package to be brazed.

[0009]

In the present invention, since the lead frame 7 having the guide leads 2a to 2f whose tips are bent downwardly outside the external leads 1a to 1c is used, when the external leads are attached to the package bases 3 and 5, the package bases Positioning can be easily performed by setting the side surfaces of the guides 2a to 2f to abut the sides.

Further, the guide leads 2a to 2f have a function of preventing the outermost outer leads from being deformed.
By making the width of ~ 2f larger than the width of the external lead,
Further, the effect can be enhanced.

[0011]

1 is a plan view showing an embodiment, and FIG. 2 is a sectional view and a perspective view showing the embodiment. In FIG. 2, (a) is A-A
Sectional view, (b) is a BB sectional view, and (c) is a perspective view. The reference numerals in FIGS. 1 and 2 are the same as those in FIG. 3, and 2a to 2f represent guide leads.

An embodiment will be described below with reference to these drawings. A metal film 5 for attaching external leads is formed on the upper surface of the peripheral portion of the ceramic substrate 3 in which the cavities 4 for mounting chips are formed. For example, 40 metal films 5 are formed on each side, and 160 metal films 5 are formed on all four sides. The pitch of the arranged metal films 5 is, for example, 0.5 mm. A metal film 5 for attaching a guide lead is formed on the side surface of the ceramic substrate 3 outside the metal film on the upper surface of the ceramic substrate 3. A total of eight metal films 5 are formed on the side surface of the ceramic substrate 3. The ceramic substrate 3 and the metal film 5 form a package base. The brazing material 6 is previously mixed on the metal film 5. The brazing material 6 is, for example, silver brazing material.

In order to attach the external lead and the guide lead to the package base, the package base is mounted on a carbon jig (not shown), and the lead frame 7 is supplied onto the package base by an automatic machine. External leads 1a to 1c and guide leads 2a to 2f having the shapes shown in FIGS. 1 and 2 are formed on the lead frame 7. External leads are formed on the lead frame 7 by 40 on each side and 160 on four sides. The width of each side is, for example, 0.2 mm, and the gap between adjacent external leads is, for example, 0.3 mm.

The guide leads 2a to 2f are formed on both sides of the external lead, and the total number is 8 and the width is, for example, 1 mm, and the tip is bent downward.
It is formed at the position where it abuts. At the position where the metal film 5 and the guide leads 2a to 2f come into contact with each other via the brazing material 6, the metal film 5 and the external leads 1a to 1c come into contact with each other via the brazing material 6 on the upper surface of the package substrate.

In this state, a carbon jig (not shown) is covered from above to sandwich the package base and the lead frame between the upper and lower carbon jigs, and the package is fed into a furnace at 800 ° C. for example, and external leads and metal Membrane 5, and guide lead 2a
~ 2f and the metal film 5 are brazed. Guide leads 2a-2f
Prevents deformation of external leads during brazing. Further, when brazing is performed, it is not necessary to consider the machining accuracy and matching of the thermal expansion coefficient with the carbon jig, so the carbon jig is simpler than the conventional one.

After that, the lead frame 7 is cut at the position of the dotted line shown in FIG. The chip is mounted in the cavity 4,
After wire bonding, seal with a seal frame and cap. The package is then mounted on a printed circuit board, for example. Even in the process, the guide leads 2a to 2f protect the outer leads inside thereof from deformation. If the guide leads 2a to 2f on both sides of the outer lead are formed to have a width wider than that of the outer lead, the mechanical strength is greater than that of the outer lead and it is particularly effective in protecting the outermost outer lead from deformation.

[0017]

As described above, according to the present invention,
By providing the guide lead on the side surface of the package, it is possible to easily and accurately align the external lead on the upper surface of the package base.

Further, by disposing the guide lead on the outer side of the outer lead, it is possible to prevent deformation of the outer lead during brazing for mounting the outer lead. Further, it is not necessary to consider the processing accuracy and the matching of the coefficient of thermal expansion in the jig (carbon jig) when brazing, and the jig is simplified.

The present invention is particularly effective in a flat package having a narrow pitch of external leads, and contributes to higher precision and lower cost of the package.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment.

FIG. 2 is a sectional view and a perspective view showing an embodiment, (a) is A
-A sectional view, (b) is a BB sectional view, and (c) is a perspective view.

FIG. 3 is a plan view and a cross-sectional view showing a conventional example, (a) is a plan view and (b) is an AA cross-sectional view.

[Explanation of symbols]

 1a to 1c are external leads 2a to 2f are guide leads 3 is a package base and ceramic substrate 4 is a cavity 5 is a package base and metal film 6 is a brazing material 7 is a lead frame

Claims (2)

[Claims] 1. A package having guide leads (2a to 2f) on the outside of arranged external leads (1a to 1c), wherein the guide leads (2a to 2f) are package bases (3, 5).
A package characterized by being fixed to the side surface of the. 2. When attaching external leads to a package base (3, 5), arranged external leads (1a to 1c) and guide leads whose tips are bent downward outside the external leads (1a to 1c). Leadframe (7) with (2a-2f)
Of the external leads (1a-1c) of the package base body (3, 5) through the brazing material (6), and the guide leads (2
a to 2f) and the side surfaces of the package substrate (3, 5) are brought into contact with each other through a brazing material (6) to be brazed.