JP2709484B2 - Method for manufacturing semiconductor device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a semiconductor device such as an IC with a lead electrode.

2. Description of the Related Art Conventionally, a pedestal system and a tape carrier system have been known as a mounting system of a semiconductor device such as an IC. In the pedestal system, the same number of pedestals as the number of IC electrodes must be formed on the wiring pattern formed on the circuit board on which the IC is to be mounted.
When mounting ICs, even if the yield rate of one pedestal for one IC is high, the yield rate of each IC will be integrated on the entire circuit board, and the overall yield rate will drop significantly There was a problem of doing. Also, the mounted IC
Even if there was a defective product inside, the IC electrode could not be removed because the electrode of the IC was directly connected to the pedestal, and the IC could not be replaced.

On the other hand, in the tape carrier method, lead electrodes corresponding to each electrode of the IC are formed on a base film. However, since the pitch between the lead electrodes changes when the base film shrinks due to temperature conditions or the like, so-called dimensional stability is poor. Further, since the base film itself is expensive, there is also a problem that the manufacturing cost is increased.

In order to overcome such problems, for example,
An IC mounting method as disclosed in JP-A-63-34935 has been proposed. The feature of this method is that a lead electrode is formed on a lead forming substrate so as to be peelable, a bump is formed at a predetermined position on the lead electrode, and an IC electrode and a lead electrode are formed through the bump. After connecting the IC with the lead electrode, the IC with the lead electrode is separated from the lead forming substrate, and the IC with the lead electrode is arranged at a required position on the circuit board, and each lead electrode is formed into a corresponding wiring pattern. To connect.

Problems to be Solved by the Invention However, the IC mounting method described in Japanese Patent Application Laid-Open No. 63-34935 also has the following problems.
The semiconductor device shown in FIG. 2 is an IC with a lead electrode in which a bump 12a and a lead electrode 13a are formed on an electrode 11a of an IC 10a.
20a is mounted on a wiring pattern 31a of a glass circuit board 30a by solder 32a. When such a semiconductor device is used by being incorporated into an electronic device or the like,
When the ambient temperature of the semiconductor device changes, IC 10a,
Stress is generated in the lead electrode 13a due to a difference in linear expansion coefficient between copper as the material of the lead electrode 13a and glass as the material of the circuit board 30a, and damage is caused to the bump 12a and the solder 32a. In order to eliminate the occurrence of this damage, the linear expansion coefficients of the IC 10a, the copper of the lead electrode 13a and the glass of the circuit board 30a are 3.5 × 10 ⁻⁶ , 17 × 10 ⁻⁶ and 8.5 × 10 ⁻⁶ , respectively. Considering that, when the chip size of the IC 10a is 10 mm, the total length of the lead electrode 13a is 2.94 mm as the length of the region l other than the soldering region, assuming that the length of the soldering region d is 0.5 mm. It is necessary, and the length of the lead electrode 13a is 3.44 mm.

IC with lead electrode having such long lead electrode
Is mounted on a substrate or the like, the mounting density is reduced.
Also, when such an IC with lead electrodes is separated from the lead forming substrate, the lead electrode electrodes are deposited by ITO (indium tin oxide), which has low affinity with the metal formed on the surface of the lead forming substrate. When the lead electrode 13a is peeled off from a film or the like, bending often occurs in the lead electrode 13a, and the yield of the IC with the lead electrode is lowered.

The present invention has been made in view of the above circumstances,
When the lead electrode is shortened and the IC with the lead electrode is peeled off from the lead forming substrate, the lead electrode does not bend, and even if the lead electrode is short, bumps or solder on the lead electrode due to stress due to changes in ambient temperature No damage to the attached part, and IC with lead electrode
It is an object of the present invention to provide a method of manufacturing a semiconductor device such as an IC with a lead electrode, which can increase the mounting density of the semiconductor device on a substrate.

Means for Solving the Problems In order to solve the above problems, a method of manufacturing a semiconductor device according to the present invention includes a method of forming a lead electrode releasably formed on a lead forming substrate and an IC connected to the lead electrode. After separating the IC with lead electrodes from the lead forming substrate,
The IC lead is placed on a forming stage having a step, and then a forming member having a suction means and a heating means is lowered, and a heating pressing body provided at a lower end of the forming member is pressed against the step. After bending the electrode, the forming member
The IC is sucked and held, and in this state, the forming member is moved to place the IC at a predetermined position on the circuit board, and then the lead electrode and the circuit board are heated by the heat of the heating member of the forming member. And the wiring pattern is soldered.

The IC with the lead electrode is separated from the lead forming substrate and placed on the forming stage. Thereafter, the forming member having the suction unit and the heating unit is lowered, and the heating press body provided at the lower end of the forming member is moved. By pressing the step, the lead electrode of the IC is bent and formed,
The IC with the lead electrode is sucked by the suction means, the forming member is moved, and the IC with the lead electrode is arranged on the circuit board.
The solder provided between the lead electrode and the wiring pattern on the substrate is melted by the heat of the heating press body, and the lead electrode and the wiring pattern are connected.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory view showing each step according to one embodiment of the present invention. FIG. 1 (a) shows a state in which an IC with lead electrodes is provided on a lead forming substrate, and FIG. ) Shows the state where the IC with lead electrodes is placed on the forming stage.
FIG. 1C shows a state in which the lead electrode of the IC with lead electrodes is bent by the forming member and the forming stage, and FIG. 1D shows a state in which the IC with lead electrodes is mounted on the circuit board by the forming member. .

In FIG. 1A, reference numeral 40 denotes a lead forming substrate, which is formed by depositing ITO (indium tin oxide) having low affinity for metal over the entire surface of a glass substrate 41 to form an ITO deposited film. It is formed. A plating layer made of copper with a thickness of about 30 μm is formed on the entire surface of the lead forming substrate 40, and the plating layer is etched by photolithography or photoetching to have a length of, for example, 1 to 2 mm. The lead electrode 13 is formed. A resist film is formed on the entire surface of the lead forming substrate 40 on which the lead electrodes 13 are formed as described above, and the resist film at a predetermined position where the electrode 11 of the IC 10 is connected on the lead electrodes 13 is removed. A protrusion made of gold or copper, a so-called bump 12, is formed by plating. The height of the bump 12 is about 30 μm. Next, after completely removing the resist film, the IC
The IC 10 is mounted on the lead electrode 13 such that the ten electrodes 13 and the bumps 12 are in contact with each other. Further, the electrodes 11 and the lead electrodes 13 of the IC 10 are connected via the bumps 12 by thermocompression bonding of both. Thus, the IC 10 becomes the IC 20 with the lead electrode.

Then, by pulling the IC 20 with lead electrodes by vacuum suction or the like, the ITO deposited film 4 constituting the lead forming substrate 40 is formed.
The lead electrode 13 is peeled off from 2, and the IC 20 with the lead electrode is separated from the lead forming substrate 40.

Such an IC 20 with lead electrodes is mounted on a forming stage 51 by a transfer means (not shown) as shown in FIG. 1 (b). A pair of steps 511 is formed on the upper surface of the forming stage 51. Above the forming stage 51, a forming member 52 is provided. The forming member 52 includes a suction collet 521 as a suction means and a pair of heating and pressing members 522 disposed on both sides of the suction collet 521. A thermode tool (corresponding to a heating means) made of molybdenum, nichrome, inconel, or the like is provided at the lower end of the heating press body 522. When a current of 200 to 300 A is applied to this thermode tool, the temperature of the thermode tool becomes almost instantaneously 400 to 500 ° C. due to the generated Joule heat. In addition, FIG.
(D) shows only the lower end portions of the suction collet 521 and the heating press body 522.

Next, as shown in FIG.
The suction collet 521 is brought into contact with the IC 10 by descending 52, and the lower end of the heating press body 522 kept at a normal temperature is pressed against the step 511 of the forming stage 51. Then, the lead electrode 13 is pressed against the step 511 by the lower end portion of the heating / pressing body 522, and is formed so as to be bent substantially 90 ° at two places.

In this state, the IC 20 with a lead electrode is sucked by the suction collet 521 and the forming member 52 holds the IC 20 with the lead electrode. Next, the forming member 52 in this state is
The I20 with the lead electrode is placed on the circuit board 30 by being moved by a moving means (not shown). That is, the lower surface of the tip portion of the lead electrode 13 of the IC 20 with a lead electrode is
It is placed so as to be in contact with the solder 32 provided at a predetermined position on the wiring pattern 31 formed on the circuit board 30. Then, the thermode tool of the heating press body 522 is energized and heated. This heat is transmitted to the solder 32 via the lead electrode 13 and the solder 32 is melted, and the connection between the lead electrode 13 and the wiring pattern 31 is completed. Thereafter, the suction of the suction collet 521 is stopped, and the forming member 52 is pulled up. Thus, the manufacture of the semiconductor device in which the IC 20 with the lead electrode is mounted on the circuit board 30 is completed.

Therefore, according to the method for manufacturing a semiconductor device of the present invention, when the lead electrode is shortened and the IC with the lead electrode is separated from the lead forming substrate, the lead electrode does not bend, and Even if the length is short, the bumps and soldered parts of the lead electrode will not be damaged by the stress due to the change of the ambient temperature, and the mounting density of the lead electrode IC on the substrate can be increased. There is an advantage that a method for manufacturing a semiconductor device such as that described above can be provided. In addition, the forming member not only has a function of simply bending the lead electrode of the IC and moving the IC to a predetermined position on the circuit board, but also has a function of wiring the lead electrode of the IC mounted on the circuit board and the wiring on the circuit board. It has a function of soldering between patterns and can perform lead forming, mounting of IC on circuit board and soldering in a series of operations, simplifying the manufacturing process and reducing the cost of semiconductor devices. Can also be planned.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing each step according to one embodiment of the present invention. FIG. 1 (a) shows a state in which an IC with lead electrodes is provided on a lead forming substrate, and FIG. ) Shows the state where the IC with lead electrodes is placed on the forming stage.
FIG. 1C shows a state in which the lead electrode of the IC with lead electrodes is bent by the forming member and the forming stage, and FIG. 1D shows a state in which the IC with lead electrodes is mounted on the circuit board by the forming member. . FIG. 2 is an explanatory view showing a state in which an IC with lead electrodes is mounted on a circuit board. 13 ... lead electrode, 20 ... IC with lead electrode, 30 ... circuit board, 31 ... wiring pattern, 32 ... solder, 40 ... lead forming board, 51 ... forming stage, 511 ...
Step, 52 Forming member, 521 Adsorbing collet, 522 Heating body.

Claims (1)

(57) [Claims] 1. A forming stage having a step after separating an IC with a lead electrode having a lead electrode releasably formed on a lead forming substrate and an IC connected to the lead electrode from the lead forming substrate. The lead electrode of the IC was bent and formed by lowering the forming member having the suction means and the heating means, and pressing the heating pressing body provided at the lower end of the forming member against the step. Thereafter, the IC is sucked and held by the forming member, and in this state, the forming member is moved to place the IC at a predetermined position on the circuit board, and thereafter, the heat is applied by the heat pressing body of the forming member. A method for manufacturing a semiconductor device, comprising: soldering between a lead electrode and a wiring pattern on the circuit board.