JPH1098264A - Method for mounting semiconductor package component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solder the leads of semiconductor package components to the pads of a substrate in good states by using a non-contacting heating system. SOLUTION: At the time of mounting semiconductor package components 13 on a substrate 11, the components 13 are held at a first height h1 at which a lead 21 comes lightly into contact with the surface of solder 17, and the lead 21 is heated in a non-contacting state by blowing a hot blast upon the lead 21 from a hot-blast blower 33. When the solder melts, the components 13 one lowered to a second height which is slightly lower than the height h1 , and while the components 13 are maintained at the second height, the solder is solidified. Therefore, the lead 21 can be soldered in a good state, since the lead 21 sinks into the molten solder 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for mounting a semiconductor package component on a substrate.

[0002]

2. Description of the Related Art When a semiconductor package component having leads at a relatively small pitch in the periphery, such as a TCP (tape carrier package) component or a QFP (quad flat package) component, is mounted on a substrate in advance by soldering to a pad portion. Is prepared, a semiconductor package component is mounted on the substrate, and a heat tool is pressed from above the leads and heated to melt the solder and solder the leads and the pads.

[0003]

However, the method of pressing the heat tool from above the lead requires that the surface of the heat tool contacting the lead is smooth and horizontal, and that the surface of the heat tool contacts the lead of the heat tool. Maintenance of the equipment because the surface needs to be cleaned regularly,
Management is troublesome.

For this reason, after the semiconductor package component is mounted on the substrate, the lead and the pad are soldered by hot air blowing, laser irradiation, light beam irradiation, etc., without heating the lead without applying external force. Methods are also being considered. However, in the non-contact heating method, the force that presses the lead against the pad does not work, so if the flatness of the lead varies, the soldering state may be uneven (a part where the lead is formed upward or a pre-coated solder Opening occurs in thin places), and leads are easily deformed. (If the mounting height of components is reduced to absorb lead variations, leads may be formed in places where leads are formed downward or where pre-coat is thick. But easily deformed). Also, since the lead is soldered while maintaining its height when mounted on the substrate, the pre-coated solder under the lead is unlikely to rotate around the lead or the upper surface even after melting.

In view of the above problems, an object of the present invention is to provide a method of mounting a semiconductor package component capable of obtaining a good soldering state of a lead and a pad by a non-contact heating method.

[0006]

According to the present invention, a semiconductor package component is placed on a substrate having a pad portion pre-coated with solder, and the leads of the semiconductor package component and the pad portion of the substrate are heated. Thus, in the method of mounting a semiconductor package component in which both are soldered, the heating is performed in a non-contact manner without applying an external force to the lead of the semiconductor package component. Holds the semiconductor package component at a first height in contact with or close to the surface of the solder on the pad, starts heating in that state to melt the solder, and then moves the semiconductor package component to the first height. In this case, the solder is lowered to a second height lower than the second height, and the solder is solidified in this state.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 and 2 show one embodiment of a method for mounting a semiconductor package component according to the present invention. This embodiment is a case where the TCP component 13 is mounted on the substrate 11. Solder 17 is pre-coated on pads 15 of substrate 11 as shown in FIG. The TCP component 13 includes a lead 21 supported by a carrier tape 19.
Is connected to the semiconductor chip 23, and the semiconductor chip 23
Of the heat resistant resin 25 including the connection portion with the lead 21
It is what was sealed with.

When components are mounted on the board 11, the board 1
1 is mounted on a flat support 27. Further, a conductive (or heat conductive) adhesive 29 is applied to a region of the substrate 11 where the semiconductor chip 23 of the TCP component 13 is mounted before the TCP component 13 is mounted. TCP parts 13
Is transferred from the supply position onto the substrate 11 while being sucked by the suction head 31 at the tip of the mounting robot.
At a predetermined position.

In this mounting method, the suction head 31
When mounting the P component 13 on the substrate 11, first,
1 holds the TCP component 13 at a _first height h _{1 such} that the TCP component ₁ is lightly in contact with the surface of the pre-coated solder 17 on the pad 15. In this state, the hot air blower 33 is positioned above the lead 21 for non-contact. Start heating with. The hot air blower 33 blows out hot air from a slit-shaped hot air outlet to simultaneously heat all the leads 21 of the TCP component 13 and the portion of the pad 15 thereunder.

If the solder 17 is melted by this heating,
TCP part 13 is lowered to a first lower than the height h ₁ second height h ₂ as shown in FIG. 2 by the suction head 31. Then, the lead 21 sinks into the molten solder 17, so that the solder 17 easily gathers around the lead 21, the solder 17 also wraps around the upper surface of the lead 21, and a good solder fillet can be formed. In addition, since the leads are lowered during the melting of the solder, variations in flatness can be absorbed without deforming the leads. Therefore, in this state, the hot air blowing is stopped and the solder 17
Solidified, a good soldering state can be obtained.

In the above-described embodiment, heating is started in a state where the lead 21 is lightly contacted with the solder 17 on the pad 15. However, the present invention is not limited to this. The heating may be started in a state of approaching (in a state of slightly floating without contact). By doing so, the solder 17 on the pad 15 can be melted in a short time. Further, the mounting method of the present invention can similarly mount not only TCP components but also QFP components.

[0012]

As described above, according to the present invention, when a semiconductor package component is placed on a substrate and then the leads of the semiconductor package component and the pad portions of the substrate are heated without contact, the semiconductor package component is removed. First, the solder is melted by holding the lead in contact with or close to the surface of the solder on the pad, and then the semiconductor package component is slightly lowered, so that the solder wraps around the lead and on the top surface, making it damp. Therefore, a good soldering state between the lead and the pad can be obtained.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing an initial stage of an embodiment of a semiconductor package component mounting method according to the present invention.

FIG. 2 is a partially cutaway front view showing the next stage.

[Explanation of symbols]

11: substrate 13: TCP part 15: pad 17: Solder 21: lead 23: semiconductor chip 27: support base 31: suction head 33: hot-air-blower unit h _1: the first height h _2: the second height

Claims (2)

[Claims] 1. A method of mounting a semiconductor package component, comprising mounting a semiconductor package component on a substrate having a pad portion pre-coated with solder and heating the lead of the semiconductor package component and the pad portion of the substrate to solder them together. The heating is performed in a non-contact manner without applying external force to the leads of the semiconductor package component, and when the semiconductor package component is mounted on the substrate, first, the lead is in contact with or close to the surface of the solder on the pad. Holding the semiconductor package component at the first height, starting heating in that state to melt the solder, and then lowering the semiconductor package component to a second height lower than the first height, and in this state A method for mounting a semiconductor package component, comprising solidifying solder. 2. The method of mounting a semiconductor package component according to claim 1, wherein said heating is performed simultaneously on all leads and pads by blowing hot air.