JP4954950B2 - Repair method for electronic parts using solder - Google Patents

Description

  The present invention relates to a method of repairing an electronic component using solder that can easily mount an alternative electronic component when a defective electronic component is removed from a circuit board.

  Machine tools, electronic devices, and the like are usually provided with a circuit board on which electronic components are mounted. Various electronic components that make up the circuit are connected to such a circuit board by soldering. However, if the electronic component has a defective solder connection to the circuit board, or the electronic component mounted on the circuit board has failed. In some cases, a repair work is required to replace the electronic component mounted on the circuit board.

  By the way, most of the solders conventionally used contain lead. For example, a Sn-Pb alloy containing lead and containing Sn and Pb as main components has a melting point as a property thereof. It has been widely used since ancient times because it is relatively low and excellent in workability, and also has good wettability and heat fatigue resistance and is inexpensive. In recent years, however, lead-added circuit boards such as Sn—Pb are discarded in the soil, and lead is dissolved from the circuit boards into the soil by acid rain and flows into rivers. As a result, environmental pollution spreads and, in turn, it may be mixed with drinking water and harm the human body. In addition, interest in protection of the global environment has been increasing, and in other countries (RoHS regulations in the EU) and in Japan, laws and regulations for lead-free soldering that does not use lead for solder have been established.

  FIGS. 5A to 5H are explanatory views showing a repair process when replacing a defective electronic component that has been adopted in recent years. Based on this figure, 100 is a circuit board, 101 Is a through hole formed in the circuit board, 102 is a land of copper foil provided around the through hole, and 103 is a lead (foot) of an electronic component soldered by Sn-Ag-Cu lead-free solder (lead-free solder) ), 104 is a solder bath in which Sn—Ag—Cu-based molten solder is introduced, 105 is a solder sucker for removing the melted solder, and a lead (foot) 103 of the electronic component is a through hole 101. And is connected to the land 102 by Sn-Ag-Cu-based lead-free solder. Then, when replacing an electronic component due to the above-described defects or the like, the lower end side of the lead 103 is immersed in a solder bath 104 in which molten Sn—Ag—Cu-based molten solder is placed (a), and the immersion is performed. When the heat of the solder bath 104 is transmitted to the fixed solder in the through hole 101 by maintaining the above, the fixed solder fixing the lead 103 is melted (b), and when the melting of the fixed solder is completed When the electronic component is lifted upward in order to remove the electronic component from the circuit board 100 (c), the molten solder is also filled in the part where the lead 103 in the through hole is removed (d), and when the circuit board 100 is separated from the solder bath 104, When the molten solder present in the through hole is cooled and solidified (e), the solder in the through hole 101 is melted by the solder sucker 105 while the solidified solder is heated and melted. Field with suction (f), to remove any molten solder in the through hole 101 (g). In these recent repair processes, Sn—Ag—Cu solder is used as the solder, and the Sn—Pb solder that has been widely used has a melting point of 183 ° C., whereas Sn—Ag— Since the Cu-based solder has a high melting point of 217 to 219 ° C., when the high-temperature heat is transmitted to the land 102 provided on the peripheral surface of the through hole 101, the circuit board 100 and the land 102 are separated. Quality degradation will occur (g). Further, when the lead of the electronic component for replacement is soldered to the circuit board 102 or the like having such a deteriorated quality, a thermal shock is applied to the land 102 or the like, and the quality becomes worse (h). ).

  As related to the above-described repair process technology, Patent Document 1 discloses an electronic component having a defect in a case where there is a defect or the like in an electronic component mounted on a printed circuit board or a solder connection portion between the printed circuit board and the electronic component. When replacing the semiconductor device with a new electronic component, there has been proposed a technique for easily separating the solder connection portion from the land, and Patent Document 2 discloses the solder connection when separating the semiconductor device from the substrate. In order to prevent a solder residue from being generated in a portion, a semiconductor device repair method for removing molten solder by injecting hot air into a solder connection portion connecting a semiconductor device and a substrate has been proposed. .

JP 2006-179556 A JP 2002-353610 A

  When performing the above-mentioned repair work, in order to remove an unspecified electronic component that is soldered to the circuit board, the solder connection part is heated and melted, but in the circuit board from which the electronic component has been removed, The solder that has connected the electronic component remains as a solder residue on the circuit board. Therefore, when newly attaching a failed electronic component, the solder residue becomes an obstacle and makes it difficult to install the electronic component in place. Therefore, it is necessary to cleanly remove the solder remaining in the through holes of the circuit board.

  Further, when repair work is performed using Sn-Pb leaded solder as the solder as in the past, the melting point of the solder was low, so that the electronic components attached to the circuit board were removed or attached. Although it was possible to suppress the thermal effect on the electronic components and circuit boards arranged in the vicinity of the solder connection part to some extent, like the repair method explained based on FIG. When performing a repair method using a general-purpose Sn-Ag-Cu solder as a lead-free solder, the melting point is higher than that of Sn-Pb leaded solder. The repair work to be performed is difficult, and since the melting point is high, the heat effect such as the amount of heat applied to the circuit board and the thermal shock is large, and there is a risk of the circuit board being damaged or thermally deteriorated. Like, half When removing the molten solder by spraying air onto the solder connection part that connects the electronic device such as a body device and the board, the hot temperature is about the same as or higher than the melting point of the solder to be removed. Since air must be injected, the amount of heat applied from the hot air is large, and there is a concern that the circuit board and surrounding electronic components may be damaged by the heat of the hot air.

  The present invention has been made in view of the above problems, and when removing and replacing an electronic component having a defect or the like mounted on a circuit board, it is possible to prevent the thermal influence on the circuit board or the like as much as possible. At the same time, it is an object of the present invention to provide a method for repairing an electronic component using solder that can easily be replaced with an alternative electronic component.

According to a first aspect of the present invention, there is provided a method of repairing an electronic component using solder, wherein a lead of an electronic component is inserted into a through hole formed in a circuit board, and the inserted lead is passed through a fixed solder to a land provided in the through hole. after mounting and connecting, when replacing the electronic component with the failure, defect or the like, the to exchange electronic components such as fault-defective, the malfunction, defects, etc. which are connected by the fixed solder to the land electronic components, a repair method of an electronic component for performing interchanging removed while melting the fixing solder, the fixed connecting the electronic component leads and those the lead, such as the failure or defect in the land a solder, those the fixed solder from low melting point solder is immersed in a low melting point solder bath melted, immersion pressure for heating and melting the lead solder connection to the fixed solder was Tei on the land A melting step, the in the immersion heating and melting step after melting the solder the fixing by the heat of the low melting point solder bath, and removal step of removing the solder connection to said leads to said lands, after the removal step, again wherein by immersing the solder in the through hole in the low melting point solder bath, performing a re-immersed heating and melting step, a該再immersion heating melting step of melting the pre-cut over de residue solder that was connected to the land Supplying the melted solder in the low melting point solder tank into the through hole, lowering the melting point of the solder in the through hole with the supply, and lowering the melting point in melting the solder that is lower the melting point, a desoldering step suck solder to the molten from within the through hole, in the through holes sucked out of the molten solder in solder wicking process, electrodeposition for replacement Inserting the component leads, and a component replacement step of connecting by fixing soldering the leads to the lands.

According to the first aspect of the present invention, when the electronic component mounted on the circuit board via the solder is replaced, the fixed solder that connects the lead and the land is melted at a lower melting point. Since the lead of the electronic component is removed from the land by being immersed in the solder bath and melted, and the solder having the low melting point solder bath having a lower melting point than the fixed solder that has connected the lead and the land is supplied to the through hole, The melting point of the solder in the through hole can be lowered, and the solder in the through hole can be sucked out and removed from the through hole in a melted state with a low melting point. It can be done safely. Furthermore, in the solder sucking work for removing the solder, the solder to be sucked has a low melting point, so the heating time until the solder melts can be shortened and the work can be performed efficiently in a short time, Moreover, since heat transfer to the circuit board and various electronic components mounted on the circuit board can be suppressed as low as possible, the temperature of the circuit board and various electronic components mounted on the circuit board increases. Failure and quality degradation can be suppressed.

According to a second aspect of the present invention, there is provided a method for repairing an electronic component using solder, wherein a lead of an electronic component is inserted into a through hole formed in a circuit board, and the inserted lead is Sn-Ag-Cu with respect to a land provided in the through hole. after attachment connected via a system fixed solder, when replacing the electronic component with the failure, defect or the like, to replace an electronic component such as the failure or defect, the said lands Sn-Ag-Cu electronic components such as the failure or defects connected by system fixed soldering, the a Sn-Ag-Cu-based fixed repair method of an electronic component for performing interchanging removed while melting the solder, such as the failure or defect electronic component leads and the person the lead the land the connected the Sn-Ag-Cu-based fixing solder Prefecture, those wherein the Sn-Ag-Cu-based than the fixed solder having a low melting point Sn-Bi based solder is dissolved To and immersed in a low-melting solder bath, an immersion heating and melting step of heating and melting the lead solder connection to the Sn-Ag-Cu-based fixing solder was Tei on the land, the low melting point with said immersion heating and melting process wherein after melting the Sn-Ag-Cu-based fixing solder by the heat of the solder bath, and removal step of removing the solder connection to said leads to said lands, after the removal process, in the low-melting-point solder bath again by immersing the solder in the through holes, before and re-immersion heating and melting step of the cut over de to melt the solder residue that was connected to the land, the low melting point solder bath by performing該再immersion heating melting step the molten Sn-Bi-based solder of the inner is supplied into the through hole, a step of lowering the melting point solder having in the through hole with the該供supply, low melting point in the step of low melting point Before Melting the Sn-Bi based solder, a desoldering step suck solder to the molten from within the through hole, in the through holes sucked out of the molten solder in solder blotting process, the leads of electronic components for interchange inserting and comprises a component replacement step of the lead to reset connection by the Sn-Ag-Cu-based fixing solder to the land, the.

According to the second aspect of the present invention, when the electronic component mounted on the circuit board via the Sn-Ag-Cu-based fixed solder is replaced, the Sn-Ag-Cu-based connecting the lead and the land is used. The lead of the electronic component was removed from the land by immersing the fixed solder in a low melting point solder bath of Sn-Bi solder that melts at a lower melting point than this, and the Sn and Ag were connected to the land. Since Sn-Bi solder having a lower melting point than the Cu-based fixed solder is supplied to the through hole, the concentration of the Sn-Ag-Cu solder in the through hole is diluted. The melting point of the solder in the hole can be lowered. Therefore, since the solder in the through hole can be sucked out and removed from the through hole in a melted state with a low melting point, the solder sucking operation can be easily and safely performed. Further, in the solder sucking work for removing the Sn-Bi solder, the solder to be sucked has a low melting point, so that the heating time until the solder melts can be shortened and the work can be efficiently performed in a short time. In addition, since heat transfer to the circuit board and various electronic components mounted on the circuit board can be suppressed as low as possible, the circuit board and various electronic components mounted on the circuit board Failures and quality degradation due to high temperatures can be suppressed. Further, when removing the Sn-Bi solder, it is removed while sucking out the solder from the through hole, so that it is possible to remove the Sn-Bi solder without scattering during the sucking operation, and to the circuit board. Since lead-free solder such as Sn-Ag-Cu solder or Sn-Bi solder is used instead of leaded solder, the lead-free solder is used for connecting electronic parts and repairing electronic parts. Can be

According to a third aspect of the present invention, there is provided a method for repairing an electronic component using solder according to the first or second aspect, wherein the lead is removed when the lead is removed in the removal step between the removal step and the re-immersion heating and melting step. A coating process is performed in which a solder material of the same material as the solder used in the low-melting-point solder bath is applied to at least the upper part of the residual solder remaining inside.

According to the third aspect of the present invention, after the removing step, the solder material of the same material as the solder used in the low melting point solder bath is applied to the residual solder as the applying step. When replacing the solder with a solder having a lower melting point than that of a fixed solder such as Sn-Ag-Cu that connected the lead and the land, in addition to the solder such as Sn-Bi that is in the low melting solder bath, Since the applied solder material is also supplied into the through hole, it is possible to quickly replace the Sn—Ag—Cu based solder with the Sn—Bi based solder.

  According to a fourth aspect of the present invention, there is provided a method for repairing an electronic component using solder according to any one of the first to third aspects, wherein the melted solder is air-filled in place of the solder sucking step of sucking the melted solder out of the through hole. It has an air blowing process that blows away by blowing.

  According to the invention of claim 4, since the solder to be blown is Sn-Bi solder having a low melting point in the air blowing step for blowing off the melted solder, the air blowing is correspondingly performed. Since the temperature can be lowered, it is possible to suppress a failure and quality deterioration caused by the high temperature of the circuit board by air blow and various electronic components mounted on the circuit board.

  According to the present invention, when the electronic component is removed, the solder remaining in the through hole is replaced with a low melting point solder having a lower melting point and easier to remove than the solder, thereby improving the solder sucking workability. Can do. In addition, since the solder has a low melting point, it is possible to suppress failure and quality deterioration due to high temperatures of the circuit board and various electronic components mounted on the circuit board, and there is no need to discard the circuit board and various electronic components. . Furthermore, lead-free solder such as Sn-Ag-Cu solder or Sn-Bi solder is used instead of leaded solder as the solder used when connecting the electronic component to the circuit board or repairing the electronic component. It is possible to prevent lead from leaching out and causing adverse effects on the human body and the natural environment.

  An embodiment as the best mode for carrying out the present invention will be described below. Needless to say, the present invention can be easily applied to configurations other than those described in the embodiments without departing from the spirit of the invention.

  FIG. 1 is a perspective view illustrating a circuit board on which electronic components according to the first embodiment are mounted. The circuit board 1 is made of a synthetic resin provided in devices such as consumer equipment and industrial equipment, and a plurality of electronic components 2 are mounted on the upper part of the circuit board 1 as shown in FIG. These are connected via a circuit pattern 3 or the like.

FIG. 2 is a cross-sectional view showing a state in which the electronic component is mounted on the circuit board. The circuit board 1 arranged horizontally has a through hole 4 formed in a direction perpendicular to the circuit board 1, and a land 5 made of a copper foil for soldering is provided on the periphery thereof. A lead (foot) 6 integrally formed in the lower part of the electronic component 2 is connected to the land 5 using Sn—Ag—Cu based fixed solder having a melting point of about 217 to 219 ° C. while being inserted into the through hole 4. Has been. In this embodiment, Sn-Ag-Cu-based fixed solder is used as the lead-free solder. Instead, Sn-Cu-based fixed solder capable of setting the melting point to 227 ° C, Sn-Ag fixed solder capable of setting the temperature to 221 ° C. may be used, and the electronic component indicated by reference numeral 2 in FIG. 2 is a connector, but as the electronic component, a capacitor, a resistor, a transformer, etc. Needless to say, it may be a passive component, an active component such as an IC, a transistor, an LSI, or a diode, or a wiring component (auxiliary component) such as a switch or a connector.

Next, a repair method for replacing electronic components mounted on a circuit board will be described below with reference to FIG. First, in a state where the lead (foot) 6 of the electronic component 2 is inserted into the through hole 4 and connected to the land 5 by the Sn—Ag—Cu-based fixed solder (state of FIG. 2) As a result, when the electronic component 2 is replaced, the lead of the electronic component 2 is inserted into the low melting point solder tank 7 into which Sn-Bi-based molten solder (melting point is 139 ° C.) melted at about 217 ° C. is introduced as an immersion heating melting process. 6 is immersed (a). And if the heat | fever of the low melting-point solder tank 7 is transmitted to Sn-Ag-Cu type | system | group fixed solder by maintaining the immersion, Sn-Ag-Cu type | system | group fixed solder which fixes the lead 6 will be seen from the downward direction. (B) The Sn—Bi based molten solder in the low melting point soldering bath 7 is fused with the Sn—Ag—Cu based molten solder that has fixed the lead 6 in the through hole. To go.

Next, in a state where all the fused solder is melted by the transfer of heat from the low-melting-point solder tank 7, as an detaching process, the electronic component 2 is lifted and separated to be detached from the circuit board 1 (c ), The portion where the lead 6 in the through hole 4 is removed is filled with the fused solder.

  Next, in the state where the leads 6 are separated from the circuit board 1, as an application process, the upper and lower sides of an alloy (residual solder) made of Sn—Ag—Cu solder and Sn—Bi solder solidified in the through holes 4 are applied. Then, an Sn-Bi solder paste 8 as a solder material is applied (d).

Next, as a re-immersion heating and melting step, the lower part of the fixed solder as the fused alloy in the through hole 4 is again immersed in the low melting point solder bath 7 and heated and melted at about 217 ° C. Next, the through hole 4 As a process of lowering the melting point inside, the heat of the low melting point solder tank 7 is transferred to the molten solder (alloy) and the solder paste 8 in the through hole 4, and the solder paste 8 is lowered to about 139 ° C. (139 ° C. or more). The melted solder paste 8 melted at the melting point and the melted solder contained in the low melting point solder tank 7 are supplied to the inside of the through hole 4, and the concentration of Sn—Ag—Cu solder in the through hole 4 is supplied with this supply. Is diluted, and the inside of the through hole 4 is replaced with almost complete Sn—Bi solder (alloy) (e), and the solder (alloy) in the through hole 4 can be melted at a low melting point. ( ).

  Subsequently, in the solder sucking process, the Sn-Bi solder in the through-hole 4 that has been heated and melted is heated and melted to the melting point or higher, and the Sn-Bi melt that has been heated and melted from the through-hole 4 by the solder sucker 9. The solder is sucked out (g). When this solder sucking step is performed, the inside of the through hole 4 is almost filled with an Sn—Bi alloy, and the melting point of the Sn—Bi alloy of this embodiment is as low as 139 ° C. Therefore, the heating for melting the Sn-Bi alloy solder does not require much time, and the melted Sn-Bi solder (alloy) in the through hole 4 can be easily removed. (H) Furthermore, thermal quality deterioration and failure of the circuit board 1 and various electronic components mounted on the circuit board 1 can be avoided. After the solder in the through-hole 4 is removed cleanly (all or almost completely removed), as a component replacement process, the lead-free solder such as Sn-Ag-Cu is used for the land 5 of the circuit board 1. The lead 6 of the electronic component 2 can be attached, and thermal quality deterioration of the circuit board 1 and various electronic components mounted on the circuit board 1 can be suppressed even after the attachment. (I).

As described above, according to the repair method of the present invention, the lead 6 of the electronic component 2 is inserted into the through hole 4 formed in the circuit board 1, and the inserted lead 6 is Sn to the land 5 provided in the through hole 4. after mounting connected -ag-Cu-based fixed via a solder, when replacing the electronic component with the failure, defect or the like, to exchange electronic component 2 such as the failure or defect, the lands 5 Sn- the electronic component 2 of the such failure or defects connected by Ag-Cu-based fixing solder, a repair method of an electronic component for performing interchanging removed while melting the Sn-Ag-Cu-based fixed solder, malfunction, defective An Sn-Bi solder that melts a lead 6 of an electronic component such as the Sn-Ag-Cu solder that connects the lead 6 to the land 5 at a lower melting point than the Sn-Ag-Cu solder. Melt And are immersed in the low melting point solder bath 7, a dip heating and melting step of heating and melting the lead 6 solder connection to the Sn-Ag-Cu-based fixed solder was Tei the land 5, a low-melting solder bath in the dip heating and melting process after melting the Sn-Ag-Cu-based fixed solder by heat, and removal step of removing the lead 6 is soldered to the lands 5, remains in the through-holes 4 when removing the lead 6 in dismounting step Sn- The solder paste 8 which is the Sn-Bi solder material having the same alloy composition as the solder used in the low melting point solder bath 7 is applied on the upper and lower sides of the residual solder (alloy) in which the Ag-Cu fixed solder and the Sn-Bi solder are fused. a coating step of, after the coating step, re-immersed heating and melting step of melting again the low melting point solder bath 7 is immersed solder through-hole 4, the remaining渣半field or the like are connected to rie de 6 the land 5 And re-immersion heating solution The Sn-Bi based solder is supplied in the vertical direction is disposed through holes 4 having the Sn-Bi based solder paste 8 and the low melting point solder bath 7 which is melted by performing the process, through-hole 4 with this feed was diluted Sn-Ag-Cu based solder concentrations have within, the steps of lowering the melting point interchanged so that the Sn-Bi based solder the solder in the through holes 4, low in the process such that low melting point Melting the solder in the through-hole 4 having a melting point (Sn—Bi solder or Sn-Bi solder fused with Sn—Ag—Cu solder), and the melted Sn—Bi solder, etc. The solder sucking process for sucking out the solder from the through hole 4 and the lead of the replacement electronic component are inserted into the through hole 4 in which the Sn-Bi-based molten solder is sucked in the solder sucking process. And a component replacement step of solder connection by Sn-Ag-Cu-based fixing solder de 5, by performing these steps, the electronic components mounted through the Sn-Ag-Cu-based fixing solder to the circuit board 1 When exchanging 2, the Sn—Ag—Cu based fixed solder connecting the lead 6 and the land 5 is immersed in a low melting point solder bath 7 of Sn—Bi based solder which melts at a lower melting point than this. The lead 6 of the electronic component 2 is removed from the land 5 by melting, and the Sn—Bi system having a low melting point solder bath having a lower melting point than the Sn—Ag—Cu based fixed solder that has connected the lead 6 and the land 5. Solder can be supplied into the through hole 4 . Therefore , it is possible to dilute the concentration of the Sn—Ag—Cu-based solder that has been in the through hole 4 and to lower the melting point of the solder in the through hole 4. Solder can be sucked out and removed from the through hole 4 in a melted state with a low melting point, so that it is not necessary to perform solder sucking work that needs to be removed at a high temperature, and the solder sucking work can be easily and safely performed. It can be carried out.

  Further, since the solder has a low melting point in the solder sucking operation for removing the Sn-Bi solder, the heating time until the solder is melted can be shortened, and the operation can be efficiently performed in a short time. 1 and various electronic components mounted on the circuit board 1 can be suppressed as low as possible, so that the failure due to the high temperature of the circuit board 1 and various electronic components mounted on the circuit board 1 And quality degradation can be suppressed. Further, when removing the Sn-Bi solder, it is removed while sucking out the solder from the through hole 4, so that it is possible to remove the Sn-Bi solder without scattering during the sucking operation.

  Furthermore, lead-free solder such as Sn-Ag-Cu solder or Sn-Bi solder, not leaded solder, is used as the solder used when the electronic component 2 is connected to the circuit board 1 or when the electronic component 2 is repaired. Because of the use of lead, it is possible to prevent adverse effects on the natural environment by making lead free.

Although an example of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the gist of the present invention. For example, in this embodiment, Sn—Ag—Cu based fixed solder has Sn of 96.5 wt%, Ag of 3.0 wt%, Cu of 0.5 wt%, and Sn—Bi based In the solder and Sn—Bi solder paste 8, Sn is 42% by weight and Bi is 58% by weight, but the weight% ratio may be appropriately selected within the scope of the present invention. In addition, if the Sn-Ag-Cu-based fixing Handa by Ri low melting point in place of the Sn-Bi based solder or Sn-Bi based solder paste, which can be a melting point of about 120 ° C. Sn- In-based solder or Sn-Bi-In-based solder capable of setting the melting point to about 60 ° C. may be appropriately selected. Moreover, when removing solder, you may employ | adopt the air blowing apparatus which blows off molten solder by air blow instead of the solder sucker 9 which sucks molten solder. In this case, since the molten solder is blown off by air blow, the solder to be blown off is Sn-Bi based in the air blow process for blowing off the melted solder. Since the solder has a low melting point, the air blow temperature can be lowered correspondingly, and the failure due to the high temperature of the circuit board and various electronic components mounted on this circuit board by air blow And quality degradation can be suppressed.

FIG. 4 is an explanatory view showing a repair method when replacing an electronic component mounted on a circuit board in the second embodiment. The steps (b) to (j) in the second embodiment are the same as those in the first embodiment (a). ) To (i), the description thereof will be omitted, and only the process (a) of Example 2 will be described below. In (a) of the second embodiment, as shown in FIG. 4, the lead (leg) 6 of the electronic component 2 is inserted into the through hole 4 and connected to the land 5 by Sn—Ag—Cu based fixed solder. In the state where the electronic component 2 is replaced due to a failure / defect, etc., Sn-Bi solder paste 8 is solidified in the through-hole 4 before the immersion heating / melting step. Apply to the bottom of the Cu-based fixed solder. As a result, the Sn—Ag—Cu solder in the through hole 4 can be diluted more quickly and the melting point can be lowered, so that the time for removing the lead 6 of the electronic component 2 from the through hole 4 can be shortened.

It is a perspective view which shows the circuit board with which the electronic component in Example 1 was mounted. It is sectional drawing which shows the state by which the electronic component was mounted in the circuit board same as the above. It is explanatory drawing which shows the process order of the repair construction method at the time of replacing the electronic component mounted in the circuit board same as the above. It is explanatory drawing which shows the process order of the repair construction method at the time of replacing the electronic component mounted in the circuit board in Example 2. FIG. It is explanatory drawing which shows the process order of the repair construction method at the time of replacing the electronic component mounted in the conventional circuit board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Circuit board 2 Electronic component 4 Through hole 5 Land 6 Lead 7 Low melting point solder tank 8 Solder material (solder paste)

Claims (4)

The lead of the electronic component is inserted into the through hole formed in the circuit board, and the inserted lead is connected to the land provided in the through hole via the fixed solder, and then attached to the land due to a failure or a defect. When replacing electronic components,
To replace an electronic component such as the failure or defect, repair of electronic components the electronic components of the fault-defects etc. connected by the fixed solder to the land, performs interchanging removed while melting the fixed solder Construction method,
The fault-defects the fixed solder Metropolitan the electronic component leads and those the lead connected to the land of immersed in low melting point solder bath solder is melted low melting point than those of the fixed solder, wherein an immersion heating and melting step of heating and melting the fixing solder the lead to the land was solder connection to Tei,
After the fixed solder is melted by the heat of the low-melting-point solder bath in the immersion heating and melting step, a removal step of removing the leads soldered to the lands,
After the removal step, and re-immersion heating and melting step of melting the by immersing the solder in the through hole in the low-melting-point solder bath again, the residue solder pre cut over de was connected to the land,
Supplying the melted solder in the low-melting-point solder bath into the through-hole by performing the re-immersion heating and melting step, and lowering the melting point of the solder in the through-hole with the supply When,
Melting the solder having a low melting point in the step of lowering the melting point, and sucking out the melted solder from the through hole;
In the through hole where the molten solder is sucked out in the solder sucking process, a lead of a replacement electronic component is inserted, and the lead is connected to the land by a fixed solder , and a component replacing process,
An electronic component repair method using solder, characterized by comprising: Inserting the leads of the electronic component in a through hole formed in the circuit board, after the lead through said insertion mounted connected via the Sn-Ag-Cu-based fixing solder to lands provided in the through hole, failure・ When replacing the electronic parts due to defects, etc.
Melt to exchange electronic components such as the failure or defect, the electronic components of the fault-defects etc. connected by the Sn-Ag-Cu-based fixing solder to the land, the Sn-Ag-Cu-based fixing solder It is a repair method for electronic parts that is removed and replaced in the
The fault-defects the Sn-Ag-Cu-based fixing solder Metropolitan the electronic component leads and those the lead connected to the land of those the Sn-Ag-Cu-based fixed solder than the low-melting Sn- Bi based solder is immersed in a low-melting solder bath being melted, the immersion heating and melting step of heating and melting the lead to the land was solder connected Tei the Sn-Ag-Cu-based fixed solder,
A step of removing the lead soldered to the land after melting the Sn-Ag-Cu-based fixed solder by the heat of the low melting point solder bath in the immersion heating and melting step;
After the removal step, and re-immersion heating and melting step of melting the by immersing the solder in the through hole in the low-melting-point solder bath again, the residue solder pre cut over de was connected to the land,
By performing the re-immersion heating and melting step , the melted Sn-Bi solder in the low-melting-point solder bath is supplied into the through-hole, and the solder contained in the through-hole is reduced with the supply. A step of melting,
Melting the Sn-Bi solder having a low melting point in the step of lowering the melting point, and sucking out the melted solder from the through hole;
The solder wicking of solder aspirated through hole melted in step, replacing parts inserted through the lead of the electronic component for interchange, to reset connection by the Sn-Ag-Cu-based fixing solder to the land of the lead Process,
An electronic component repair method using solder, characterized by comprising: Same as the solder used in the low-melting-point solder bath at least above the residual solder remaining in the through hole when the lead is removed in the removal step between the removal step and the re-immersion heating and melting step. repair method of the electronic component by soldering as claimed in claim 1 or 2, characterized in that the coating step of coating the solder material of the material.   4. The method according to claim 1, further comprising: an air blowing step of removing the molten solder by blowing off with an air blow instead of a solder sucking step of sucking out the molten solder from the through hole. Repair method of electronic parts by soldering as described in the item.

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