JP2528562B2 - Inner lead joining method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of bonding an inner lead of a tape carrier to a pad of an IC chip in a manufacturing process of IC parts.

[0002]

2. Description of the Related Art As a method of manufacturing IC parts, FIGS.
As shown in FIG. 3, the bumps 25 are provided on the tips of the inner leads 24 of the tape carrier 23, and the IC chip 21 manufactured and diced on the wafer is positioned at a predetermined position and provided on the IC chip 21. Bumps 25 at the tip of each inner lead 24 on each pad 22
Position the tape carrier 23 so that they face each other, and press the tips of the inner leads 24 together with the heated bonding tool 26 to bond the bumps 25 and the pads 22, and then the IC chip 21 and the tape. The carrier 23 is sealed with resin, the outer leads of the tape carrier 23 are cut and separated from the tape carrier 23, and the IC
Methods of obtaining parts are known.

[0003]

However, in the bonding method using the bonding tool 26, the parallelism between the bonding tool 26 and the precision stage 27 on which the IC chip 21 is mounted is extremely high as the size of the IC component increases. If the accuracy is not maintained, highly reliable bonding cannot be achieved, which is difficult to realize in terms of manufacturing technology and cost. Also, since the heated bonding tool 26 is used, it easily becomes dirty, and if the dirt causes surface roughening, the bonding becomes difficult. Since a defective portion is generated and reliable joining cannot be ensured, it is necessary to frequently perform cleaning or tool replacement, which causes a problem that productivity is reduced.

In view of the above problems of the prior art, it is an object of the present invention to provide a method for bonding an inner lead to a pad of an IC chip with high reliability, even for a large IC component, with good production and production. .

[0005]

According to the inner lead joining method of the present invention, a step of arranging each inner lead of a tape carrier on each pad of an IC chip, and a pressing means for pressing the inner lead. And a step of scanning the infrared irradiation section provided separately from the infrared irradiation section, and sequentially radiating infrared rays to each inner lead from a direction having a certain angle to heat the inner lead and the pad, The method further comprises a step of sequentially pressing the heated inner lead at a position behind the infrared irradiation position in the scanning direction by a pressing means to bond the inner lead and the pad. A roller can be used as the pressing means, and the roller can be rolled to sequentially press the inner leads.

The inner lead joining method of the present invention is
The step of arranging each inner lead of the tape carrier on each pad of the C chip, and the pressing means for pressing the inner lead has a certain angle from the infrared irradiation section provided separately from the pressing means. The inner leads and the pads are heated by irradiating each inner lead with infrared rays from different directions, and the inner leads and the pads are joined by sequentially pressing the heated inner leads with a pressing means. Is performed from the rear side in the scanning direction toward the inner lead in front of the pressing means, and the infrared irradiation is blocked by the pressing means when the pressing means descends and presses the inner lead.

Further, the inner lead joining method of the present invention is
The step of arranging each inner lead of the tape carrier on each pad of the IC chip, and the pressing means for pressing the inner lead has a certain angle from the infrared irradiating part provided separately from the pressing means. The inner leads and the pads are heated by irradiating each inner lead with infrared rays from different directions, and the inner leads and the pads are joined by sequentially pressing the heated inner leads with a pressing means. Is performed from the rear in the scanning direction toward the inner lead in front of the pressing means, and when the pressing means descends to press the inner lead, the inner lead pressed by the mirror provided in the pressing means is It is characterized by irradiating infrared rays.

[0008]

According to the present invention, since the inner lead is sequentially pressed by the pressing means, the technique established by wire bonding or the like can be applied easily and at low cost, and the pressing means can be parallel to the stage. Even if the degree of contact is not high, each inner lead can be pressed firmly and joined, and highly reliable joining is possible.
Since the infrared irradiation unit provided separately from the pressing unit performs infrared irradiation in a direction with a certain angle, the pressing unit is at a low temperature, dirt is unlikely to adhere, and cleaning and replacement of the pressing unit are small. It is possible to obtain high productivity.

Further, if infrared rays are sequentially irradiated to the inner leads by scanning of the infrared ray irradiation section, energy efficiency is high and proper heating state can be stably obtained for all the inner leads. Further, at that time, when the infrared irradiation unit and the pressing unit are integrally moved and scanned, the infrared irradiation time is stopped by stopping the scanning movement at the time of pressing by blocking the infrared irradiation by the pressing unit when pressing by the pressing unit. It does not become overheated for a long time, and it can be efficiently heated by irradiating the inner lead pressed by the mirror.

If the roller is further pressed,
The scanning and pressing mechanism can be easily and speeded up.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the inner lead bonding method of the present invention will be described below with reference to FIGS.

Reference numeral 1 denotes an IC chip, and a plurality of aluminum pads 2 are formed in parallel on each of the four peripheral portions on the upper surface thereof. Reference numeral 3 is a tape carrier, in which an opening 4 larger than its planar shape is formed at a position where the IC chip 1 is to be arranged, and an inner lead 5 made of copper foil corresponding to each pad 2 of the IC chip 1 from its four periphery. Has been extended. The inner leads 5 are arranged on the lower surface of the tape carrier 3. Gold bumps 7 are provided in the front end corresponding to the pads 2 of each inner lead 5 in the previous step. For bonding the gold bumps 7 to the surface of the inner leads 5, a bonding bump made of gold or tin is used. Metal plating 6 is applied. The upper surface of the IC chip 2 is covered with the insulating film 8 except for the pad 2.

Reference numeral 11 denotes an infrared irradiating section for irradiating infrared rays.
Reference numeral 2 denotes a pressing means for pressing the inner leads 5 toward the pad 2, which is mounted on a scanning body (not shown) that intermittently moves in the parallel direction of the inner leads 5 at an arrangement pitch of the leads. The means 12 is provided on this scanning body so as to be capable of urging downward and retracting and rising as shown by the white arrow. The infrared irradiation unit 11 is arranged at a position at a proper distance in the scanning direction forward in order to secure a space for arranging the driving unit with respect to the pressing unit 12, and is inclined by a proper angle toward the rear side in the scanning direction. The inner lead 5 facing the means 7 or the previous inner lead 5 is irradiated with infrared rays.

In the above structure, each inner lead 5
The IC chip 1 and the tape carrier 3 are relatively positioned so that the bumps 7 provided on the corresponding pads 2 are arranged on the corresponding pads 2, and then the infrared irradiation unit 11 is operated,
The scanning body is intermittently moved along the row of pads 2 on each side of the IC chip 1 by the arrangement pitch thereof, and when the scanning body stops moving on each pad 2, the pressing means 12 is driven up and down. Then, after the inner leads 5, the bumps 7 and the pads 2 are heated by the infrared rays emitted from the infrared ray irradiation section 11, the pressing means 12 descends and the inner leads 5 and the bumps 7 are pressed toward the pads 2, The bumps 7 and the pads 2 are joined by applying heat and pressure to the interface between the bumps 7 and the pads 2 to form a gold-aluminum alloy.

By repeating this bonding operation in sequence, all the inner leads 5 are bonded to the pads 2 of the IC chip 1 via the bumps 7.

Since the pressing means 12 sequentially presses the inner leads 5 in this manner, the established technique such as wire bonding can be applied easily and at low cost, and the pressing means 12 and the IC chip 1 can be used. Even if the stage on which the stage is mounted does not have a high degree of parallelism, each inner lead 5 can be reliably pressed and joined, and highly reliable joining is possible. Further, the inner lead 5 is heated by irradiation of infrared rays. Therefore, the pressing means 12 is at a low temperature, dirt is unlikely to adhere, cleaning and replacement of the pressing means are small, and high productivity can be obtained. Further, since infrared rays are sequentially irradiated to the inner leads 5 by moving the scanning body, heating can be performed immediately before joining, energy efficiency is high, and proper heating state is stable for all the inner leads 5. can get.

Next, a second embodiment of the present invention will be described with reference to FIG. In the above-described first embodiment, the example in which the infrared irradiation unit 11 is arranged on the front side in the scanning direction with respect to the pressing means 12 is shown. However, in the present embodiment, the infrared rays are arranged on the rear side in the scanning direction with respect to the pressing means 12. It is arranged so as to radiate infrared rays obliquely forward from the irradiation unit 11 to heat the inner lead 5 one front of the inner lead 5 facing the pressing means 12, and as shown in FIG. While the pressing means 12 is rising, the inner lead 5 is heated, and while the pressing means 12 is descending and pressing the inner lead 5 as shown in FIG. It is configured to cut off the irradiation of.

According to this embodiment, it is possible to prevent the inner lead 5 from being overheated by being irradiated with excessive infrared rays while the scanning body is stopped to press the inner lead 5.

Next, a third embodiment of the present invention will be described with reference to FIGS. In this embodiment, similarly to the second embodiment shown in FIG. 2, the inner lead 5 which is one front of the inner lead 5 facing the pressing means 14 from the infrared irradiating section 11 arranged on the rear side in the scanning direction with respect to the pressing means 14. In addition to irradiating infrared rays toward the leads 5, a mirror 15 is provided between a pair of pressing portions 14a of the pressing means 14 as shown in FIG. 5, and the pressing means 14 is provided as shown in FIG. Is heated, the front inner lead 5 is heated, and the pressing means 14 presses the inner lead 5 as shown in FIG. 4B.
When the is pressed, infrared rays are reflected by the mirror 15, and the pressed inner leads 5 are irradiated with the infrared rays to heat the inner leads. According to this embodiment, since the inner lead 5 is irradiated with the infrared light reflected by the mirror 15 while the inner lead 5 is being pressed by the pressing means 14, efficient heating is possible.

Next, the fourth and fifth embodiments of the present invention will be described with reference to FIG. In the above embodiments, the infrared irradiator 11 is moved to sequentially heat the inner leads 5 immediately before pressing, but in these embodiments, the inner leads 5 aligned in one direction are collectively heated. I am trying.
Therefore, in the fourth embodiment shown in FIG. 6A, the scan mirror 16 is repeatedly scanned at high speed to irradiate infrared rays over the array section of the inner leads 5.
In the fifth embodiment shown in (b) of FIG.
Infrared rays are radiated over the arrangement section of the inner leads 5 at 7, and after the inner leads 5 are heated by radiating the infrared rays as described above, the inner leads 2 are sequentially pressed by a pressing means (not shown). I am trying to do it.

Next, a sixth embodiment of the present invention will be described with reference to FIG. In the above embodiment, the pressing means 12, 13, 14 move up and down to press the inner lead 5.
In this embodiment, the pressing roller 18 is used as the pressing means, and the pressing roller 18 is rolled in the arrangement direction of the inner leads 5 and sequentially pressed. According to this embodiment, the mechanism of the pressing means can be simplified and the joining can be speeded up easily.

[0022]

According to the inner lead joining method of the present invention, since the inner leads are sequentially pushed by the pushing means,
It can be implemented easily and at low cost by applying established technology such as wire bonding, and it can surely press each inner lead even if the parallelism between the pressing means and the stage on which the IC chip is mounted is not high. Bonding is possible, highly reliable bonding is possible, and the inner lead is heated by infrared irradiation in a direction with a certain angle from an infrared irradiation unit provided separately from the pressing unit. Has a low temperature, is less likely to be contaminated with dirt, requires less cleaning and replacement of the pressing means, and exhibits high productivity.

Further, if infrared rays are sequentially radiated to the inner leads by scanning of the infrared radiating section, energy efficiency is high and proper heating state can be stably obtained for all the inner leads. Further, at that time, when the infrared irradiation unit and the pressing unit are integrally moved and scanned, the infrared irradiation time is stopped by stopping the scanning movement at the time of pressing by blocking the infrared irradiation by the pressing unit when pressing by the pressing unit. It does not become overheated for a long time, and it can be efficiently heated by irradiating the inner lead pressed by the mirror.

When the roller is further pressed,
The scanning and pressing mechanism has an effect such that the scanning pressing mechanism can be easily realized at high speed.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part in a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 shows a second embodiment of the present invention, and FIGS. 3 (a) and 3 (b) are partial cross-sectional front views of a main part before and after pressing the inner lead by the pressing means.

FIG. 4 shows a third embodiment of the present invention, and FIGS. 4 (a) and 4 (b) are partial cross-sectional front views of a main part before and when the inner lead is pressed by the pressing means.

FIG. 5 is a perspective view of a pressing means used in the third embodiment of the present invention.

6A and 6B show modified examples of the infrared irradiating section used in the present invention, FIG. 6A is a perspective view of a fourth embodiment, and FIG. 6B is a perspective view of a fifth embodiment.

FIG. 7 is a perspective view showing a pressing means according to a sixth embodiment of the present invention.

FIG. 8 is an explanatory diagram of a conventional inner lead joining method.

FIG. 9 is a vertical sectional front view showing a joined state of an IC chip and an inner lead of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 IC chip 2 Pad 3 Tape carrier 5 Inner lead 11 Infrared irradiation part 12 Pressing means 14 Pressing means having a mirror 18 Pressing roller

Claims (4)

(57) [Claims] 1. A step of arranging each inner lead of a tape carrier on each pad of an IC chip, and a pressing means for pressing the inner lead is scanned by an infrared irradiation section provided separately from the pressing means. Then, the step of heating the inner leads and pads by sequentially irradiating each inner lead with infrared rays from a direction having a certain angle from the infrared irradiating section , and heating the inner leads with infrared rays. Teru
An inner lead joining method, comprising a step of joining the inner lead and the pad by sequentially pushing by a pushing means at a position rearward of the shooting position in the scanning direction . 2. A roller is used as the pressing means, and the roller is rolled.
The inner lead bonding method according to claim 1 , wherein the inner leads are sequentially pressed . 3. A tape carrier on each pad of the IC chip.
A process of arranging each inner lead of
The pressing means that presses the cord is separate from the pressing means.
Direction with a certain angle from the infrared irradiation unit provided
Irradiates each inner lead with infrared rays
Process of heating the pad and pad and the heated inner
The inner lead and pad
And irradiating infrared rays from the rear side in the scanning direction toward the inner lead in front of the pressing means, and when the pressing means descends to press the inner leads, the infrared irradiation is performed by the pressing means. Characterized by shutting off
In Narido joining how to. 4. A tape carrier on each pad of the IC chip.
A process of arranging each inner lead of
The pressing means that presses the cord is separate from the pressing means.
Direction with a certain angle from the infrared irradiation unit provided
Irradiates each inner lead with infrared rays
Process of heating the pad and pad and the heated inner
The inner lead and pad
And irradiating infrared rays from the rear in the scanning direction toward the inner lead in front of the pressing means, and the mirror provided in the pressing means when the pressing means descends and presses the inner lead. to and irradiating infrared rays with respect to the inner leads are pressed by
Ruin Narido bonding method.