JPS6347269B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a method of manufacturing a semiconductor device, and more particularly to a method of manufacturing a semiconductor package using a lead frame that enables positioning of a lid and a base of the package.

(2) Background of the technology The production of semiconductor device packages involves manufacturing a package base (hereinafter referred to as the base) on which a semiconductor chip is mounted.
This is accomplished through the steps of attaching the lead to the lead and mounting the cap onto the lead-substrate assembly (lead base) thus produced.

Attachment of such a lid is usually performed with the assembly inverted. This technique will be briefly described with reference to the plan view in Figure 1a and the cross-sectional view in Figure 1B.
Prepare a jig 1, position the cap 2 as shown in the figure, then position the lead frame 4 using the pins 3 of the jig, and then place the base on which the chip 6 is fixed on the lead frame 4. 5, and the lead base and cap are sealed in a furnace using the weight of the base 5. In addition, in the figure, 7 indicates a connection wire.

(3) Conventional technology and problems In the encapsulation of the semiconductor package described above,
It was necessary to position the semiconductor chip (dice), the wire-attached substrate, and the cap using a special jig. Conventionally, the lead base was turned upside down after the tip and wire attachment work, which often resulted in damage to the wires and tips. Furthermore, the above-mentioned pin 3 of the jig has a diameter of 0.85 mm and is bent and severely damaged. In addition, the jig must be modified every time the outer shape of the base is changed, which increases the cost of manufacturing semiconductor packages.

(4) Purpose of the Invention In view of the above-mentioned drawbacks of the prior art, the present invention eliminates the need for a special jig, eliminates the need to invert the lead base, which is an assembly of the lead and the package base, and allows the base and cap to be separated. It is an object of the present invention to provide a method for assembling a semiconductor package using a lead frame that allows positioning.

(5) Structure of the Invention The purpose is to provide a process for fixing a semiconductor chip to a package base, preparing a lead frame consisting of a plurality of leads and a frame for connecting them;
A process of bending or cutting a part of the frame part so that its tip extends above the lead to form a guide part that serves as a positioning guide for the cap; a process of fixing the lead onto the package base; This is achieved by a method of manufacturing a semiconductor device including the step of positioning and fixing the cap on the package base by means of a guide portion extending above the surface of the base.

(6) Examples of the invention Embodiments of the present invention will be described in detail below with reference to the drawings.

Referring to FIG. 2, a side view is shown in a, a top view is shown in b, and a perspective view is shown in c. In both figures, the central portion of the lead base is cut away for simplicity. In addition, in Fig. 2, 11 is the lead frame (therefore, the base).
12 is a package base, and 13 is a cap. As can be understood from a and b in the figure, the pair of leads are formed symmetrically to each other. Furthermore, the sandy area indicated by the reference numeral 14 represents sealing glass, and this glass is melted in the furnace, cooled, and solidified to integrally seal the base 12 and the cap 13.

In manufacturing a semiconductor package, a chip (not shown) is fixed to the package base 12 as shown in FIG. 1b. In the embodiment shown in FIG. 2, a U-shaped cut-out (also referred to as a guide) 15 is formed by bending or cutting out a lead frame 11 consisting of a plurality of leads and a frame portion connecting these leads. has been done. The pair of U-shaped cut-outs 15 define both ends of the rectangular recess and extend upward from the surface of the package base 12 as shown in the figure. If the width and height of the cut-out portion 15 are appropriately selected taking into account the thickness of the cap 13, the cap 13 will fit neatly into the recess when the lead is fixed onto the package base 12. , no jig is required for positioning the cap 13.

Such U-shaped cut-and-raised portions are formed by easily bending or cutting them in a normal pressing process when manufacturing a lead frame. There is no problem in mounting the lead frame because it is carried out in exactly the same way as in the case of conventional lead frames.

A lead frame used in another embodiment of the present invention is shown in FIG. 3 in a side view in FIG.
1 is the outermost lead in the longitudinal direction of the lead frame (therefore, the base), 22 is the lead immediately adjacent to the lead 21, 23 is the package base (base), and 24
indicates a cap, the central portions of the lead frame and base are shown cut away for simplicity, and the sanded portion 25 represents the sealing glass.

In the illustrated lead frame, a stop 21' for restricting the longitudinal movement of the cap is formed on the outermost lead 21 by cutting and raising, and a stop 21' for restricting the lateral movement of the cap is formed on the lead 22 adjacent to the lead 21. A stop 22' is similarly formed.
These stops 21' and 22' extend above the surface of the package base 12, similar to the cut-out 15 in the example shown in FIG. 2, and their heights are selected as appropriate by calculating the thickness of the cap 24. The cap 24 then fits neatly into the recess defined by a total of four stops, so that the cap can be easily positioned without the use of any jig.

The outermost lead in the longitudinal direction of the lead frame shown in FIG. 3 can be deformed as shown in the perspective view of FIG. 4. When the outermost lead 31 is cut up to form a stop 31' similar to the stop 21' in FIG. 41 (only one of which is shown) and a stop 41' similar to stop 31' at its distal end. A lead 31 extending upward and two leads 4 extending downward are provided at the outermost side in the longitudinal direction of the lead frame.
1 and formed with stops 31' and 41' respectively, the lower stop 41' is positioned at the base 33, and the upper stop 31' extends above the surface of the base 12, so that the cap Effective for 34 positioning. Note that sealing glass is placed on the upper surface of the base 33 and the lower surface of the cap 34.
Furthermore, in the illustrated embodiment, a space is formed by the lead 31 and the base portion 45 of the stopper 41', and even if excess glass flows out during sealing, it can escape into this space. There are advantages.

Like the lead 11 in FIG. 2, the leads 21, 31, 41 shown in FIGS. 3 and 4 can be easily formed by normal press working when forming a lead frame. Also, the lead base can form a package with the chip facing up rather than upside down. Note that the shape of the cut-and-raised part of the lead frame is not limited to the shape of the above embodiment.

(7) Effects of the Invention As explained above in detail, in manufacturing the semiconductor package according to the present invention, a U-shaped cut-out is provided on the outermost lead frame, or a U-shaped cut-out is provided on the outermost lead frame. By forming a cut in the lead frame and the lead immediately adjacent to it, and by forming a stop at the tip of the lead frame, the cap can be easily positioned without using a jig without inverting the lead base. In a modified example, the outermost lead is provided with a cut-up and a cut-down, and a stop is formed at the tip of the lead, thereby making it possible to position both the base and the cap without using a jig. Furthermore, such leads can be easily formed by normal press processing when forming the lead frame, and are therefore highly effective in reducing the cost of manufacturing semiconductor packages.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the cap positioning of a semiconductor package according to the prior art, in which a is a plan view of the jig and the cap, b is a cross-sectional view, and FIG. 2 is a diagram showing the lead frame used for manufacturing the semiconductor package according to the present invention. In the figure shown, a is a side view, b is a plan view, and c is a side view.
3 is a perspective view, FIGS. 3a, b, and c are views similar to FIGS. 2a, b, and c of another embodiment of the present invention, and FIG. 4 is a perspective view of still another embodiment. 11, 21, 31... Longitudinal outermost lead of the lead frame, 12, 23, 33... Package base (base), 13, 14, 34... Cap,
14...Sealing glass, 15...U-shaped cut-out, 2
2...Lead immediately next to lead 21, 21', 2
2', 31', 41'...stop, 41...cut down, 4
5...Taibu.

Claims (1)

[Claims] 1. A step of fixing a semiconductor chip to a package base, and preparing a lead frame consisting of a plurality of leads and a frame for connecting the leads, and bending a part of the frame or bending the leads. By cutting and raising a part, the guide portions 15 and 2 whose tips extend upwards from the leads and serve as positioning guides for the cap.
2'; fixing the lead onto the package base 12; and fixing the cap to the package base 12 by means of the guide portions 15, 22' extending above the surface of the package base 12. In the method of manufacturing a semiconductor device, the step of forming the guide portion includes the step of forming a pedestal portion 45 between the lead 31 and the stoppers 31' and 41'. A method for manufacturing a semiconductor device, characterized in that: