JPH11330688A - Local heating equipment of electronic component for repair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide local heating equipment of an electronic component for repair which does not exert thermal influence upon a soldering part, by preventing radiation and convection heat transfer to mounted components arranged in a peripheral part, in the case of exchange or repair of IC packages such as a ball grid array(BGA) and a quad flat package(QFP), and components such as a resistor and a capacitor which are mounted on a printed wiring board by soldering. SOLUTION: A shielding case 7 for heat isolation covers the upper part of a repair component of a printed wiring board 3, is brought into contact with the plane part of the printed wiring board 3, and shields the component. A nozzle part jetting hot air for fusing solder of a soldering part of the repair component is installed inside the shielding case 7. The hot air jetted from the nozzle part is made to circulate in the shielding case 7, and then discharged from exhaust vents 9 formed in the upper part of the shieding case 7. As a result, transfer of heat to adjacent peripheral components is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a printed wiring board,
Repair parts for replacing or repairing IC packages such as ball grid array (BGA) and quad flat package (QFP) mounted by soldering, and parts such as resistors, capacitors, connectors, and switches Prevents the transmission of heat due to radiation and convection heat to the mounted components located around the
The present invention relates to a local heating device for a repair electronic component that can perform a satisfactory repair operation without damaging a soldered portion of a mounted component by heat.

[0002]

2. Description of the Related Art ICs such as a ball grid array (BGA) package and a quad flat package (QFP) mounted on a conventional printed wiring board by soldering.
Packages, resistors, capacitors, connectors,
For example, as shown in FIG. 5, a local heating heater used when replacing or repairing parts such as a switch is a hot air 5 jetted from a hot air jetting nozzle 1.
Since the tip of the hot air jet nozzle 1 is open, the hot air 5 is dispersed in all directions, and the radiation and convective heat transfer 6 cause the following problems. (1) For example, a defective ball grid array (BGA)
When the package 2 is repaired (repaired), the radiant heat transfer and convection transfer of the hot air blown out from the nozzle portion of the local heater to the peripheral mounting component 4 mounted on the periphery adjacent to the repair component. Upon receiving the heat 6, the soldered portion is semi-melted, and the printed wiring board becomes defective. (2) In the worst case, the solder is in a semi-molten state without being completely melted, and the solder is re-solidified, and the surface becomes rough and granular, and the original brightness of the solder is lost. Then, it becomes a defective product with poor soldering. (3) Further, when a plurality of BGA packages are mounted adjacent to each other, since the soldered portion of the BGA package is at the lower portion of the package, the appearance cannot be inspected. The printed circuit board cannot be confirmed even when the printed circuit board becomes defective, and may be defective during a circuit operation test of the printed wiring board.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art, and to provide a ball grid array (BGA) mounted on a printed wiring board by soldering and a quad flat. Radiation and convection heat transfer to the mounted parts arranged around the repair parts when replacing or repairing IC packages such as packages (QFP) and parts such as resistors, capacitors, connectors, switches, etc. An object of the present invention is to provide a local heating device for a repair electronic component, which can prevent heat from being transmitted due to heat and does not cause thermal damage to a soldered portion and can perform a good repair operation.

[0004]

Means for Solving the Problems In order to achieve the object of the present invention, the present invention is configured as described in the claims. That is, the present invention provides an electronic component mounted on a printed wiring board as described in claim 1.
A local heating device used for repairing, wherein the local heating device is placed over the repair component and closely shields a flat portion of the printed wiring board to shield the inside. The apparatus further includes a local heater having a nozzle for blowing hot air for melting the solder of the soldering part of the repair part.The hot air blown from the nozzle is circulated in the shield case, and then the shield is heated. This structure has a structure in which air is exhausted upward through an exhaust hole provided in an upper portion of the case to prevent heat from being transmitted to mounted peripheral components. According to a second aspect of the present invention, in the first aspect, the heat-shielding case according to the first aspect, in which the shield part closely shields a flat portion of the printed wiring board, has a bottom surface portion of the shield case formed of the printed wiring board. This is a local heating device for a repair electronic component having a spring mechanism that presses and presses against a flat portion. By using the local heating device for the repair electronic component having the structure as described in claim 1 or 2, only the area for disposing the repair electronic component is heated and the soldered portion is re-melted. Repair can be performed, and the heat of the hot air does not propagate to the soldering part of other electronic components arranged around the repaired component, so the solder is semi-melted or re-melted and the printed wiring board is defective And the reliability of the repair process can be improved. Further, since the heat history of the electronic components arranged around the repair component can be suppressed, it is possible to prevent the electronic components from being thermally damaged. Furthermore, the heating range for repair can be limited to the area of the repaired electronic component only, and the distance between components that can avoid the heat influence on other electronic components can be reduced, and the high-density printed wiring board can be reduced. There is an effect that can be implemented.

[0005]

FIG. 1 is a perspective view showing an example of a local heating device for a repair electronic component of the present invention, and FIG. 2 is a cross-sectional view of FIG. In the figure, a printed wiring board 3 has a ball grid array (BGA) package 2 and peripheral mounting components 4 such as an IC package such as a quad flat package (QFP) and resistors, capacitors, connectors, and switches. Parts are mounted. A shield case 7 of a local heating device for the repair electronic component having the hot air jet nozzle 1 therein is disposed above the BGA package 2 as the repair electronic component in close contact with the plane portion of the printed wiring board 3. . At this time, a spring member is provided on a spring support plate 14 provided on the upper part of the shield case 7 in order to press the shield case 7 against the flat portion of the printed wiring board 3 so that the shield case 7 comes into close contact therewith.
For example, a spring 8 is provided so that the flat portion of the printed wiring board 3 and the lower contact surface of the shield case 7 can be in close contact with each other by springback. The spring member may be a coil spring, a spiral spring, a leaf spring, or a leaf spring, and various springs made of a resilient metal or alloy can be used. Further, if necessary, a structure may be employed in which a portion of the shield case 7 in contact with the plane portion of the printed wiring board 3 is sealed with a packing made of a heat-resistant polymer such as a silicon resin for maintaining airtightness. Is also good. FIG. 3 shows a shield case 7 used in the local heating device for repair electronic components of the present invention.
As shown in (a) and (b), it is necessary to exhaust hot air upward through a plurality of exhaust holes 10 and exhaust holes 9 to prevent the transfer of heat in the direction of mounted peripheral components. is there. The shape of the exhaust hole 9 and the elongate elongate hole 10 for exhausting hot air provided on the upper part of the heat shield case may be any shape such as a circle, an oval, a slit, or a rectangle. However, any shape may be used as long as it has an exhaust hole (hole) having a function of discharging hot air to the upper part of the shield case, and does not specify the shape of the hot air exhaust hole. By adopting the local heating device as described above, the hot air blown out from the hot air blowing nozzle 1 is protected by the shield case 7.
Is evacuated from the upper part of the shield case 7 after circulating through the inside of the housing, so that heat can be released upward and the transfer of heat to the mounted peripheral parts can be effectively prevented. It is possible to suppress troubles such as re-melting of the attachment portion, reduce defective products of the printed wiring board, and improve the reliability of the printed wiring board.

[0006]

By using the local heating device for repaired electronic components of the present invention, the soldered portion only in the area where the repaired electronic components are arranged is re-melted, and the soldered portion is located adjacent to the repaired component. Since semi-melting or re-melting of the soldered portion of other electronic components arranged in the periphery can be prevented, defective products of the printed wiring board can be reduced, and the reliability of the printed wiring board can be improved. effective. In addition, it is possible to suppress the heat history of the electronic components disposed around the repair component, and to suppress damage to the electronic components due to heat. Furthermore, since the heating range in the case of repair can be limited to only the area of the repaired electronic component, it is possible to reduce the distance between components that can avoid the influence of heat on other surrounding electronic components, and it is possible to cope with high-density mounting. effective.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the structure of a local heating device for a repair electronic component exemplified in an embodiment of the present invention.

FIG. 2 is a schematic view showing a cross-sectional structure of a local heating device for a repair electronic component exemplified in the embodiment of the present invention.

FIG. 3 is a schematic view showing a structure of a shield case of the local heating device exemplified in the embodiment of the present invention.

FIG. 4 is a view showing an appearance of a BGA package as a repair electronic component exemplified in the embodiment of the present invention.

FIG. 5 is a schematic view showing a hot air heating state of a conventional repair electronic component.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Hot air nozzle 2 ... Ball grid array (BGA) package 3 ... Printed wiring board 4 ... Peripheral mounting parts 5 ... Hot air 6 ... Radiant and convective heat transfer 7 ... Shield case 8 ... Spring 9 ... Exhaust hole 10 ... Exhaust Slot 11 BGA package 12 BGA soldering terminal (solder ball) 13 Gas inlet 14 Spring support plate

Claims (2)

[Claims] 1. An electronic component mounted on a printed wiring board,
A local heating device used for repairing, wherein the local heating device is placed over the repair part and closely shields at a flat portion of a printed wiring board, and a shield case for heat prevention; and Has a heater for local heating having a nozzle portion for blowing hot air for melting the solder of the soldering portion of the repair part, the hot air blown from the nozzle portion circulates in the shield case, and A local heating device for a repair electronic component, wherein the device is configured to be discharged upward through an exhaust hole provided in an upper part of a case to prevent heat from being transmitted to peripheral components mounted thereon. 2. The heat-shielding case according to claim 1, wherein the shield case closely shields the flat portion of the printed wiring board, and presses the bottom portion of the shield case against the flat portion of the printed wiring board to form a spring. A local heating device for a repair electronic component, comprising a mechanism.