JP2008283017A - Soldering method of component-mounting board, and the component-mounting board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means to suppress stress in a jointing portion, while using a component mounting board without further adding another element to the basic alloy of solder. <P>SOLUTION: The soldering method of the component mounting board solders a printed circuit board and an electronic component, by inserting the lead of the electronic component into the through hole of the printed circuit board, wherein a reflow process is carried out in the range of predetermined temperature and time conditions, after soldering. Additionally, according to these method, the component mounting board in which stress in the solder jointing portion is suppressed can be obtained. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a soldering method for a component mounting board on which an electric / electronic component is mounted on a printed wiring board, and the component mounting board.

  In recent years, flow soldering and reflow soldering using a tin-based alloy containing no lead (generally called lead-free solder) has been widely performed.

  By the way, when soldering using lead-free solder, it is known that whiskers are generated from a solder joint during use of a component mounting board after soldering. In particular, it is known that whisker generation is accelerated in a high-temperature and high-humidity environment, and depending on the usage environment, whisker generation from solder cannot be ignored.

  The driving force of whiskers generated from solder joints is presumed to be internal stresses in the joints that occur during the period of use, and the origin is the pressure caused by the formation and growth of tin oxide due to oxidation or corrosion of tin. It is also presumed that the pressure is due to the growth of intermetallic compounds generated at the boundary between tin and the copper substrate.

Uses lead-free solder that is a tin (Sn) -based alloy containing at least one of cobalt (Co), manganese (Mn), iron (Fe), and nickel (Ni) as a means for suppressing the generation of whiskers It is known that a lead-free solder joint is formed (see Patent Document 1). According to Patent Document 1, the growth of an intermetallic compound of Sn and Cu (Cu ₆ Sn ₅ ) at the joint between the lead-free solder and a member to be soldered containing copper (Cu) is suppressed. Thus, the increase in internal stress at the joint can be suppressed, and the generation and growth of whiskers from Sn and Sn-based alloys can be suppressed.

  In addition, as another means for suppressing the generation of whiskers, copper or copper alloy using zinc (Zn) or a Zn compound and Sn—Zn based solder in which the remaining part is basically Sn or Sn compound. It is known to perform soldering (see Patent Document 2). According to Patent Document 2, the growth of the Sn—Cu compound, which is the cause of whisker generation, is suppressed, and the generation of whiskers can be suppressed. Furthermore, by adding Zn, a Zn oxide film (ZnO) is formed on the solder surface, so that oxidation of Sn in the solder is prevented, internal stress due to the formation of Sn oxide is not generated, and whisker It is supposed to suppress the occurrence.

JP 2005-288478 A JP 2006-289493 A

  However, the technique disclosed in Patent Document 1 is limited to the case where the solder alloy system is the addition of Co, Mn, Fe, and Ni to a Sn-0.7 mass% Cu alloy. Whether an alloy is effective, for example, Sn—Ag—Cu alloy, Sn—Zn alloy, Sn—Bi alloy or the like is unknown. Even if a small amount of Co, Mn, Fe, and Ni is effective in the above-mentioned various alloys, Sn-based alloys to which a small amount of Co, Mn, Fe, and Ni are added are special solder materials. In order to carry out the present invention, it is necessary to newly purchase and use a solder material to which Co, Mn, Fe, and Ni are added, and it is necessary to review the soldering conditions sensitive to the composition. This leads to an increase in the cost of the soldering process.

  In addition, when the technique disclosed in Patent Document 2 is actually applied, it is necessary to replace an alloy to which Zn is not added with an alloy to which Zn is added, and at that time, an alloy containing Zn is soldered. The trouble that the condition must be reviewed arises. In addition, since Zn is easily oxidized, additional restrictions arise in terms of process management such as oxygen concentration management and soldering state confirmation during flow soldering and reflow soldering. In addition, there is a new problem that even if process management is performed, variations in quality cannot be avoided.

  That is, in each patent document, Sn generated from solder by adding another element to a basic alloy such as Sn—Ag—Cu, Sn—Cu, Sn—Zn, Sn—Bi, Sn—Sb, etc. Although an invention for suppressing the generation of whiskers has been disclosed, the addition of an element changes the solderability and deterioration of the joint during use compared to the case where the other element is not added. However, it can be said that this problem is unclear in each patent document. If this problem has not been elucidated, there will be a load on adjustment of the process, and there is a new problem that it will be extremely difficult to form sufficient joints and component mounting boards from the viewpoint of reliability and quality stabilization. appear.

  Therefore, in view of the above problems, the present invention provides a means for suppressing stress in a joint portion generated during use of a component mounting board without adding another element to the basic alloy of solder. With the goal.

According to a first aspect of the present invention, there is provided a component mounting board soldering method in which a lead of an electric / electronic component is inserted into a through hole of a printed wiring board and the printed wiring board and the electric / electronic component are soldered. A soldering method for a component mounting board, wherein a reflow treatment is performed in the following temperature condition and time condition range after the soldering.
Conditions: When the solidus temperature of the solder is Ts (° C.) on the coordinates of time X (seconds) and temperature Y (° C.), the following conditions are satisfied.
Y ≧ 300-40log ₁₀ X
Y ≦ {(980-80log ₁₀ X) / 3}
Y ≧ (Ts + 3)

According to a second solution of the present invention, the printed circuit board and the electrical circuit are connected by a soldering process in which leads of electrical and electronic components are inserted into through holes of the printed circuit board and preheating, jet, high temperature, and cooling zones are provided. A component mounting board soldering method for soldering an electronic component, wherein a reflow treatment is performed in the high temperature zone in a range of the following temperature condition and time condition: It is.
Conditions: When the solidus temperature of the solder is Ts (° C.) on the coordinates of time X (seconds) and temperature Y (° C.), the following conditions are satisfied.
Y ≧ 300-40log ₁₀ X
Y ≦ {(980-80log ₁₀ X) / 3}
Y ≧ Ts + 3
Y ≦ 300

A third solving means of the present invention is a method for soldering a component mounting board in which a lead of an electric / electronic component is inserted into a through hole of the printed wiring board and the printed wiring board and the electric / electronic component are soldered. A soldering method for a component mounting board, wherein a reflow treatment is performed in the following temperature condition and time condition range after the soldering.
Conditions: When the solidus temperature of the solder is Ts (° C.) on the coordinates of time X (seconds) and temperature Y (° C.), the following conditions are satisfied.
Y ≧ 300-40log ₁₀ X
_{Y ≦ {(980-80log 10 X)} / 3}
Y ≧ Ts + 3
Y ≦ 260

According to a fourth solution of the present invention, the printed circuit board and the electrical circuit are connected by a soldering process in which leads of electrical and electronic parts are inserted into through holes of the printed circuit board and preheating, jet, high temperature, and cooling zones are provided. A component mounting board soldering method for soldering an electronic component, wherein a reflow treatment is performed in the high temperature zone in a range of the following temperature condition and time condition: It is.
Conditions: When the solidus temperature of the solder is Ts (° C.) on the coordinates of time X (seconds) and temperature Y (° C.), the following conditions are satisfied.
Y ≧ 300-40log ₁₀ X
Y ≦ {(1280−130 log ₁₀ X) / 4}
Y ≧ Ts + 3
Y ≦ 240

  A fifth solving means of the present invention is the component mounting board soldering method according to any one of the first to fourth solving means, wherein the solder is a tin-based alloy.

According to a sixth aspect of the present invention, there is provided a component mounting board in which the printed wiring board and the electric / electronic component are soldered in a state in which the lead of the electric / electronic component is inserted into the through hole of the printed wiring board. The component mounting board is characterized in that after the soldering, a reflow process is performed in a range of the following temperature condition and time condition.
Conditions: When the solidus temperature of the solder is Ts (° C.) on the coordinates of time X (seconds) and temperature Y (° C.), the following conditions are satisfied.
Y ≧ 300-40log ₁₀ X
_{Y ≦ {(980-80log 10 X)} / 3}
Y ≧ (Ts + 3)

According to a seventh solution of the present invention, the printed wiring board and the printed wiring board are connected by a soldering process having preheating, jet, high temperature, and cooling zones in a state where the leads of the electrical and electronic parts are inserted into the through holes of the printed wiring board. A component mounting board to which the electrical / electronic component is soldered, wherein the component mounting board is subjected to a reflow process in the following temperature conditions and time conditions after the soldering. .
Conditions: When the solidus temperature of the solder is Ts (° C.) on the coordinates of time X (seconds) and temperature Y (° C.), the following conditions are satisfied.
Y ≧ 300-40log ₁₀ X
Y ≦ {(980-80log ₁₀ X) / 3}
Y ≧ Ts + 3
Y ≦ 300

According to an eighth aspect of the present invention, there is provided a component mounting board in which the printed wiring board and the electric / electronic component are soldered in a state in which the lead of the electric / electronic component is inserted into the through hole of the printed wiring board. The component mounting board is characterized in that after the soldering, a reflow process is performed in a range of the following temperature condition and time condition.
Conditions: When the solidus temperature of the solder is Ts (° C.) on the coordinates of time X (seconds) and temperature Y (° C.), the following conditions are satisfied.
Y ≧ 300-40log ₁₀ X
Y ≦ {(980-80log ₁₀ X) / 3}
Y ≧ Ts + 3
Y ≦ 260

According to a ninth solution of the present invention, the printed wiring board is connected to the printed wiring board by a soldering process having preheating, jet, high temperature, and cooling zones in a state where the leads of the electrical and electronic parts are inserted into the through holes of the printed wiring board. A component mounting board to which the electrical / electronic component is soldered, wherein the component mounting board is subjected to a reflow process in the following temperature conditions and time conditions after the soldering. .
Conditions: When the solidus temperature of the solder is Ts (° C.) on the coordinates of time X (seconds) and temperature Y (° C.), the following conditions are satisfied.
Y ≧ 300-40log ₁₀ X
Y ≦ {(1280−130 log ₁₀ X) / 4}
Y ≧ Ts + 3
Y ≦ 240

  A tenth solving means of the present invention is the component mounting board according to the sixth to ninth solving means, wherein the solder is a tin base alloy.

  By applying the present invention, it is possible to suppress the occurrence of solder whiskers in a component mounting board that is flow soldered. At the same time, it is possible to provide a component mounting board in which the joint does not deteriorate and cracks do not occur even when subjected to thermal fatigue due to repeated application of a load to the joint during temperature changes during use.

  An embodiment of the present invention will be described. In addition, it cannot be overemphasized that embodiment of this invention is not limited to the specific example shown below.

  A first example of a preferred embodiment of the present invention is a component mounting board soldering method in which a lead of an electric / electronic component is inserted into a through hole of a printed wiring board and the printed wiring board and the electric / electronic component are soldered. Then, after the soldering, the reflow treatment is performed in the following temperature condition and time condition ranges.

This condition means that, on the coordinates of time X (seconds) and temperature Y (° C.), when the solidus temperature of the solder is Ts (° C.), it is one point in a region that satisfies the following conditions. is there.
Y ≧ 300-40log ₁₀ X
Y ≦ {(980-80log ₁₀ X) / 3}
Y ≧ (Ts + 3)

Here, the straight line of Y = Ts + 3 shows the case of using Sn-3Ag-0.5Cu (mass%) solder (melting point: solidus temperature 217 ° C.) (Y = 220). When the solder composition and melting point (solidus temperature Ts) are different, the straight line Y = Ts + 3 is different from Y = 220. The region satisfying this condition is a triangular region surrounded by three straight lines as shown in FIG. Preferably, it is a quadrangular region surrounded by four straight lines including the condition of Y ≦ 300, more preferably a quadrangular region surrounded by four straight lines including the condition of Y ≦ 260, more preferably This is a quadrangular region surrounded by four straight lines of Y ≧ 300−40 log ₁₀ X, Y ≦ {(1280−130 log ₁₀ X) / 4}, Y ≧ Ts + 3, and Y ≦ 240. Among these conditions, the condition of Y ≦ 300 or Y ≦ 260 means the upper limit of the temperature range, which is determined in consideration of the heat resistance of the printed wiring material or the electric / electronic component to be soldered. . A diagram including the condition of Y ≦ 260 is shown in FIG.

The grounds for determining the conditions are as follows.
(1) Lower temperature limit: For Ts + 3 (° C.), at temperatures below the lower limit, even if long-time treatment (4 hours or more) was performed, no effect was seen in reducing whiskers, so the limit adversely affects productivity. It is.
(2) Lower time limit: For “Y = 300-40log ₁₀ X” which is the straight line on the left side (the shorter time side) of FIGS. 1 and 2, on the left side (the shorter time side) from this line, whisker is reduced. This is because the effect was not seen. Although the time is shortened as the temperature is increased, it has been experimentally confirmed that the upper limit of time varies logarithmically with respect to a linear change in temperature.
(3) Upper time limit: For “Y = {(980-80log ₁₀ X) / 3}”, which is a straight line on the right side (longer side) in FIGS. 1 and 2, the right side (longer side) from this line This is because the deterioration of the joint due to thermal fatigue becomes significant. Similar to the lower time limit described above, the time was shortened as the temperature increased, but it was confirmed by experiments that the upper time limit changed logarithmically with respect to a linear change in temperature.
(4) Upper temperature limit: In the case where Y = 300 or Y = 260 is defined as the upper limit as a preferable condition, the heat-resistant temperature of electric and electronic parts is generally about 260 ° C. Furthermore, there are electrical and electronic parts that have durability performance even at high temperatures, and therefore the upper temperature limit can be set as appropriate depending on the durability performance of the electrical and electronic parts. For Y = 300, if Y> 300, the maximum value of X is smaller than 10 (seconds) and the allowable range of X is reduced, so that the reproducibility of the effect of the present invention is difficult to be exhibited. There is also an implication that an upper temperature limit is provided in order to obtain reproducibility.
(5) Summary: Under the temperature and time conditions within the above ranges (1) to (4), a great effect is seen in reducing whiskers, and there is almost no deterioration of the joint due to thermal fatigue.

  According to a second example of a preferred embodiment of the present invention, a lead of an electric / electronic component is inserted into a through hole of a printed wiring board, and the printed wiring board is connected to the printed wiring board by a soldering process having preheating, jet, high temperature, and cooling zones. A method for soldering a component mounting board for soldering the electric / electronic component, wherein the reflow treatment is performed in the high temperature zone in a range of the temperature condition and the time condition described above. The difference from the first example described above is that the component mounting board is subjected to a reflow process under a predetermined condition in a series of soldering operations, and the second example may be industrially desirable.

  About the 1st example and 2nd example of preferable embodiment of this invention, not only the soldering method of a component mounting board but the component mounting board soldered by this method also becomes the object.

The solder used in the first and second examples of the preferred embodiment of the present invention is a tin-based alloy. Preferred is a tin-based alloy containing no lead, and more preferred is Sn—Ag, Sn—Cu, Sn—Ag—Cu, Sn—Ag—Cu—Bi, Sn—Ag—Cu—Sb, Sn—Ag—. Bi-In, Sn-Ag-In, Sn-Zn, Sn-Zn-Bi, and Sn-Sb. More preferably, the alloys include Al, Si, P, S, Ti, V, Cr, Mn, Fe, Co, Ni, Ga, Ge, As, Se, Zr, Nb, Mo, Pd, Hf, Ta. , W, Pt, and Au are added by 0.1 mass% or less.
In each of the above embodiments, the solder may be a tin-based alloy and can be applied to eutectic solder (Sn-37% Pb: solidus temperature of about 183 ° C.) that has been widely used so far. However, the use of lead has been regulated because it is an environmentally hazardous substance, and it is preferably a tin-based alloy that does not contain lead from the viewpoint that the effect of application of the present invention greatly appears.

In addition, the example of the soldering method of the component mounting board | substrate with which embodiment of this invention is applied is shown.
(1) When performing soldering by reflowing a surface mount component, the temperature profile at the time of reflow may be adjusted to satisfy the conditions in the above temperature and time range, and reflow soldering may be performed.
(2) The present embodiment is also applied to the flow soldering by inserting the lead of the electric / electronic component into the through hole of the printed wiring board after the step of reflowing and soldering the surface mount component. When this embodiment is applied, whether the mounting part of the surface mounting component is not heated above the melting point of the solder (only the flow soldering part is heated), or the surface mounting component is fixed. It is desirable to take the above measures.
(3) The present embodiment also applies to the case where the lead of the electrical / electronic component is inserted into the through hole of the printed wiring board after the process of soldering the surface-mounted component by reflow treatment twice on the front and back surfaces. Applied. When this embodiment is applied, whether the mounting part of the surface mounting component is not heated above the melting point of the solder (only the flow soldering part is heated), or the surface mounting component is fixed. It is desirable to take the above measures.
(4) When soldering by inserting leads of electrical and electronic parts into through holes in a printed wiring board, the temperature of the jet and the time range during which the jet is bathed may be the conditions within the above temperature and time range. However, it is necessary to take into account the loss of land and leads due to Cu biting.

  An example corresponding to the embodiment of the present invention will be described.

[Sample description]
Printed wiring board: Cu wiring and resist were provided on an epoxy resin (FR4) substrate provided with glass cloth, and Cu lands and Cu through holes were provided at locations where insertion parts were to be placed. The size was 10 cm × 15 cm.
-Parts: Insertion parts for terminal connector 2 stages 10 poles, 10 resistors and 5 relays. The lead (terminal) was made of Cu and Cu alloy, the connector lead and the resistance lead were each plated with Sn, and the relay lead was SnAgCu pre-soldered.

[Soldering conditions]
-Flow conditions: A flux was applied to the printed wiring board, and Sn-3Ag-0.5Cu (mass%) solder was flowed to obtain a component mounting board. As the flux, a low-residue type post-flux (manufactured by Tamura Kaken, SOLDERITE EC-15-7) was used. The melting point of the solder having the same composition is a solidus temperature of 217 ° C. and a liquidus temperature of about 220 ° C. Conveyance speed: 1m / min. The jet temperature was 250 ° C.
As the solder, Sn-0.7Cu (melting point of solder: solidus temperature 227 ° C., conveyance speed: 1 m / min, jet temperature 250 ° C .; No. 28), Sn-2.5Ag-0.5Cu-3 0.0Bi-1.0In (solder melting point: solidus temperature 202 ° C., conveyance speed: 1 m / min, jet temperature 230 ° C .; No. 29), parts and substrates having the same specifications as above A component mounting board was obtained by flow soldering.

[Heat treatment conditions]
-Reflow treatment: The flow-mounted component mounting substrate was heat-treated in a batch-type reflow furnace at the temperature and time (No. 2-29) shown in Table 1. Two substrates were produced at each temperature and time condition.

[Evaluation condition 1: Evaluation of whiskers and nodules]
・ One component mounting board (No. 2-29: Examples and Comparative Examples) reflow-treated under each condition, and one board (No. 1: conventional example) not subjected to reflow treatment, 85 ° C., humidity It was left for 2000 hours in an 85% environment. Using SEM, the entire solder fillet surface on the solder side was observed. When a straight rod-like substance having a diameter of several μm and a length of several tens of μm or a curved string-like substance having a diameter of several μm was detected, if Sn was a main component by EDX analysis, it was determined to be a whisker. Moreover, when the state which has a rough surface and the area | region of several micrometers-dozens of micrometers protrudes was observed, this was determined as a nodule. A substrate in which no whisker or nodule was generated was evaluated as “◯”, a substrate in which no whisker was generated and in which a nodule was generated was evaluated as “Δ”, and a substrate in which even one whisker was generated was determined as “x”.
In addition, in the test of this example, all of the substances detected as the above forms (whiskers, nodules) were mainly composed of Sn, and there were no substances mainly composed of other components.

[Evaluation condition 2: Evaluation of cracks]
Separately from the above, one component mounting board (No. 2 to 29: Examples and Comparative Examples) subjected to reflow processing under each condition and one board (No. 1: conventional example) not subjected to reflow processing The sample was put into a temperature cycle test tank and a temperature cycle test was conducted. The temperature was kept at −40 ° C. and 120 ° C. on the high temperature side for 30 minutes each, and the temperature change interval was within 5 minutes. This temperature profile was repeated 3000 times. Thereafter, the cross-sections of the five solder joint portions (per substrate) of the terminal connection connector were polished, and the state of deterioration was observed. In the cross section, it was found that a plurality of cracks occurred in the solder region or the compound region in all the samples. For the longest crack, if the length exceeds the remaining length (the minimum length along the longitudinal direction of the lead of the portion where the lead remains soldered after the temperature cycle test), ×, remaining Inspections for which the length was less than or equal to ○ were performed on each cross section. In addition, the reference | standard which divides the obtained sample into an Example and a comparative example made the Example into which the crack length becomes three or more places in 5 places of junction parts, or less, and was set as the comparative example.

[Evaluation results]
The results are shown in Table 1.

From Table 1, whiskers and nodules for substrates (No. 3-5, 8, 12-15, 18, 19, 21-24: Examples) subjected to reflow treatment within the specified temperature and time range of the present invention. It was found that whisker generation was suppressed. Also, in the five cross-sections examined, all crack lengths are less than the remaining length, or only one remaining length is greater than 4 and the remaining length is less than 4 lengths, or 2 locations are greater than the remaining length and 3 locations are the remaining length. The following results were obtained, and it was found that there was little deterioration due to thermal fatigue.
On the other hand, the substrate reflow-treated under the conditions (No. 2, 7, 10, 11, 17, 20: comparative example) below the time prescribed in the present application and the conditions below the temperature prescribed in the present application (No. 26, 27: comparison) For the substrate reflowed in Example) and the substrate that was not reflowed after flow soldering (No. 1: conventional example), generation of whiskers and nodules was observed. In addition, with respect to the substrates (No. 6, 9, 16, 25: comparative examples) subjected to reflow treatment under the conditions specified for the time specified in the present application, the crack length is longer than the remaining length at 5 or 4 locations, and the heat fatigue resistance It turned out to be inferior.

  Further, an example using Sn-0.7Cu (mass%) as a solder (No. 28: Example) and Sn-2.5Ag-0.5Cu-3.0Bi-1.0In (mass%) are used. In all the examples (No. 29: Example), whiskers were not generated, and the crack length after fatigue deterioration was as short as the remaining length or less.

It is a graph which shows an example of the relationship between temperature conditions and time conditions. It is a graph which shows another example of the relationship between temperature conditions and time conditions.

Claims (10)

A method for soldering a component mounting board in which a lead of an electric / electronic component is inserted into a through hole of a printed wiring board and the printed wiring board and the electric / electronic component are soldered, and after the soldering, the following temperature condition and A soldering method for a component mounting board, wherein reflow processing is performed within a range of time conditions.
Conditions: When the solidus temperature of the solder is Ts (° C.) on the coordinates of time X (seconds) and temperature Y (° C.), the following conditions are satisfied.
Y ≧ 300-40log ₁₀ X
Y ≦ {(980-80log ₁₀ X) / 3}
Y ≧ Ts + 3 A method for soldering a component mounting board in which a lead of an electric / electronic component is inserted into a through hole of a printed wiring board and the printed wiring board and the electric / electronic component are soldered, and after the soldering, the following temperature condition and A soldering method for a component mounting board, wherein reflow processing is performed within a range of time conditions.
Conditions: When the solidus temperature of the solder is Ts (° C.) on the coordinates of time X (seconds) and temperature Y (° C.), the following conditions are satisfied.
Y ≧ 300-40log ₁₀ X
Y ≦ {(980-80log ₁₀ X) / 3}
Y ≧ Ts + 3
Y ≦ 300 A method for soldering a component mounting board in which a lead of an electric / electronic component is inserted into a through hole of a printed wiring board and the printed wiring board and the electric / electronic component are soldered, and after the soldering, the following temperature condition and A soldering method for a component mounting board, wherein reflow processing is performed within a range of time conditions.
Conditions: When the solidus temperature of the solder is Ts (° C.) on the coordinates of time X (seconds) and temperature Y (° C.), the following conditions are satisfied.
Y ≧ 300-40log ₁₀ X
Y ≦ {(980-80log ₁₀ X) / 3}
Y ≧ Ts + 3
Y ≦ 260 A method for soldering a component mounting board in which a lead of an electric / electronic component is inserted into a through hole of a printed wiring board and the printed wiring board and the electric / electronic component are soldered, and after the soldering, the following temperature condition and A soldering method for a component mounting board, wherein reflow processing is performed within a range of time conditions.
Conditions: When the solidus temperature of the solder is Ts (° C.) on the coordinates of time X (seconds) and temperature Y (° C.), the following conditions are satisfied.
Y ≧ 300-40log ₁₀ X
Y ≦ {(1280−130 log ₁₀ X) / 4}
Y ≧ Ts + 3
Y ≦ 240   The method for soldering a component mounting board according to claim 1, wherein the solder is a tin-based alloy. A component mounting board in which the printed wiring board and the electric / electronic component are soldered in a state where the lead of the electric / electronic component is inserted into the through hole of the printed wiring board, and the following temperature condition and A component mounting board that is subjected to reflow processing within a range of time conditions.
Conditions: When the solidus temperature of the solder is Ts (° C.) on the coordinates of time X (seconds) and temperature Y (° C.), the following conditions are satisfied.
Y ≧ 300-40log ₁₀ X
Y ≦ {(980-80log ₁₀ X) / 3}
Y ≧ (Ts + 3) A component mounting board in which the printed wiring board and the electric / electronic component are soldered in a state where the lead of the electric / electronic component is inserted into the through hole of the printed wiring board, and the following temperature condition and A component mounting board that is subjected to reflow processing within a range of time conditions.
Conditions: When the solidus temperature of the solder is Ts (° C.) on the coordinates of time X (seconds) and temperature Y (° C.), the following conditions are satisfied.
Y ≧ 300-40log ₁₀ X
_{Y ≦ {(980-80log 10 X)} / 3}
Y ≧ Ts + 3
Y ≦ 300 A component mounting board in which the printed wiring board and the electric / electronic component are soldered in a state where the lead of the electric / electronic component is inserted into the through hole of the printed wiring board, and the following temperature condition and A component mounting board that is subjected to reflow processing within a range of time conditions.
Conditions: When the solidus temperature of the solder is Ts (° C.) on the coordinates of time X (seconds) and temperature Y (° C.), the following conditions are satisfied.
Y ≧ 300-40log ₁₀ X
_{Y ≦ {(980-80log 10 X)} / 3}
Y ≧ Ts + 3
Y ≦ 260 A component mounting board in which the printed wiring board and the electric / electronic component are soldered in a state where the lead of the electric / electronic component is inserted into the through hole of the printed wiring board, and the following temperature condition and A component mounting board that is subjected to reflow processing within a range of time conditions.
Conditions: When the solidus temperature of the solder is Ts (° C.) on the coordinates of time X (seconds) and temperature Y (° C.), the following conditions are satisfied.
Y ≧ 300-40log ₁₀ X
Y ≦ {(1280−130 log ₁₀ X) / 4}
Y ≧ Ts + 3
Y ≦ 240   The component mounting board according to claim 6, wherein the solder is a tin-based alloy.

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