AUDIO SOLDER ALLOY

TECHNICAL FIELD

The present invention relates to audio solder alloy that is applicable to joining solder for connecting electronics parts on a printed circuit board which is used for an audio system or the like.

BACKGROUND

In order to improve sound quality in sound-reproducing system (audio products) as audio system, it is not only required to select electronics parts to be used in the sound-reproducing system but also to collectively study circuit design in the printed circuit board used for an amplifier constituting this sound-reproducing system, an arrangement of parts in the printed circuit board, quality of connecting wire to be used for the connecting wire (oxygen free copper etc.) between a final (output) amplifier and a speaker and the like.

Among them, the selection of electronics parts and the circuit design when using the printed circuit board have been already executed as an improvement for sound quality but in order to further improve sound quality and to provide a sound-reproducing system with high auditory sensation assessment, solder for joining the electronics parts has been noticed.

As the solder for joining the electronics parts, the (Patent Document 1) through (Patent Document 3) and the like have been known.

DOCUMENTS FOR PRIOR ART
Patent Documents

Patent Document 1: Japanese Patent Application Publication No. H11-277290

Patent Document 2: Japanese Patent Application Publication No. 2002-239780

Patent Document 3: Japanese Patent Application Publication No. 2003-230980

The Patent Document 1 relates to quaternary solder alloy in which Ni is added to (Sn.Ag.Cu), which improves any resistance to thermal shock. The Patent Document 2 relates to solder alloy to pursuit joining reliability and the like and the Patent Document 3 is an invention relating to solder alloy to improve joining reliability.

SUMMARY OF THE INVENTION
Problems to be Solved by the Invention

However, the above-mentioned Patent Documents 1 through 3 do not disclose that a composition of solder alloy for joining electronics parts and contained amounts thereof exert an influence on sound quality, auditory sensation assessment and the like.

Applicants of this application confirmed on the basis of various kinds of examinations that, by changing the metal composition of solder alloy and/or the contained amounts thereof, sound quality and/or auditory sensation were changed. In other words, it was understood that combination of the composition of solder alloy for joining electronics parts and contained amounts thereof were an important primary factor to improve sound quality and to acquire high auditory sensation assessment.

Accordingly, the present invention solves such a conventional problem and its object is to provide audio solder alloy that is applicable to audio system or the like which allows sound quality to be improved and allows high audio sensation assessment to be acquired.

Means for Solving the Problems

In order to solve the problem, audio solder alloy according to the invention contains Ag of 0.8 through 1.20% by mass, Cu of 0.65 through 0.75% by mass, In of 0.002 through 0.004% by mass, Ni of 0.01 through 0.02% by mass, Pb of 0.005% or less by mass and the remainder of Sn. Selecting such composition elements and their contained amounts enables to be acquired audio solder alloy with high sound quality and high auditory assessment value.

Effects of the Invention

According to the invention, senary solder alloy is configured in which (tin, Sn, argent, Ag and copper, Cu) are principle ingredients and indium, In, nickel, Ni and lead, Pb, in minuscule quantities, are added thereto, and their contained amounts are set to their appropriate values so that it is possible to accomplish audio solder alloy with high sound quality and high auditory assessment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing an example of an auditory assessment device which is presented to the subject invention.

FIG. 2 is a circuit diagram of a low pass filter circuit showing an example of a filter circuit used in the auditory assessment device shown in FIG. 1.

FIG. 3 is a diagram showing an arrangement of parts on a printed circuit board of the low pass filter circuit.

FIG. 4 is a circuit diagram of a high pass filter circuit showing an example of the filter circuit used in the auditory assessment device shown in FIG. 1.

FIG. 5 is a diagram showing an arrangement of parts on a printed circuit board of the high pass filter circuit.

EMBODIMENT FOR IMPLEMENTING THE INVENTION
Embodiment

Next, a case where an example of audio solder alloy according to the invention is applied to joining solder for jointing electronics parts which are used for a circuit system constituting the above-mentioned audio system will be described more in detail referring to drawings and the like.

As the joining solder which could exert any influence on any sound quality and/or auditory assessment, pieces of audio solder alloy which were presented to the auditory assessment were prepared.

(1) Auditory Audio Solder Alloys:

As the joining solder for joining the electronics parts, ternary flux cored solder alloy (solder alloy made of tin, Sn, argent, Ag and copper, Cu), which is the most widely used as the joining solder for joining the electronics parts, is basically used.

It was confirmed by auditory tests that some metals, in minuscule quantities, were added to this ternary solder alloy to change auditory assessment so that species of the following metal were selected as trace metals based on various kinds of repeated auditory tests.

(Added Metals)

[Indium, In; Nickel, Ni; antimony, Sb; Bismuth, Bi; Iron, Fe; Arsenic, As; and Lead, Pb]

Since lead, Pb is a trace element contained in tin, Sn constituting the ternary solder alloy, the auditory assessment was actually carried out on the senary solder alloy in which the above-mentioned trace metals were added to the quaternary solder alloy of (tin, Sn, argent, Ag and copper, Cu) and lead, Pb.

(2) Numbers of Prepared Joining Audio Solder Alloys:

As the metals, to be added, two species of metals were selected other than lead, Pb, and their amounts of addition and the amounts of addition of other quaternary metal were regulated so that the audio solder alloys were made. Nine species of audio solder alloys which had the same metal composition as each other and contained different amounts of addition thereof were actually prepared for auditory.

(3) Auditory Equipment (Auditory Assessment Device)

FIG. 1 Shows an example of an auditory assessment device 10. As an electronic circuit for auditory assessment, filter circuits NW each constituting the electronic circuit by soldering discrete parts on the printed circuit board (circuit board) are illustrated.

Since any stereophonic recording is generally performed on sound source, reproducing equipment is constituted of a pair of right and left speakers, which will be described by using only a single side one.

Further, if CD (compact disk) is sound source, any sound source reproducing apparatus such as CD player having a rotation system reproduces the sound source to listen to it when reproducing the sound source. However, any uneven rotation, eccentricity or the like may generate in the rotation when reproducing the CD sound source so that there is possibility such that any influence thereof is exerted over different portions every auditory tests, which impedes any appropriate auditory assessment. Thus, in this moment, when reproducing the sound source for the auditory tests, any sound source reproducing apparatus such as CD player having a rotation system was not directly used. In the other words, when CD was sound source, the CD player reproduced CD and any semiconductor memory such as USB memory temporarily stored it to be used as sound source so that the sound source could be reproduced under the same condition.

An audio signal from the sound source 20 is supplied to a filter circuit NW through an output amplifier 30 and is divided into two ways, middle/low range and high range, in this example. Accordingly, this filter circuit NW (NW0) is constituted of a low pass filter (LPF) 40 and a high pass filter (HPF) 50, both circuits of which are constituted using printed circuit boards (circuit boards).

An output signal from the low pass filter 40 is supplied to a speaker for middle/low range (woofer) WF through connection lines La, Lb. Similarly, an output signal from the high pass filter 50 is supplied to a speaker for high range (tweeter) TW through connection lines Lc, Ld.

FIG. 2 shows an example of the low pass filter 40 which is constituted of a parallel circuit of an iron-core coil 43 and a capacitor 44. As the iron-core coil 43, a coil having a diameter of 1.2 mmØ is used in this example. The coil having inductance value of 0.45 mH is used. The capacitor 44 having a withstand voltage of 250 V (DC) and 12 μF is used.

This low pass filter 40 actually utilizes a printed circuit board 46, as shown in FIG. 3, on a surface of which the iron-core coil 43 and the capacitor 44 are arranged with them having a shown positional relationship. Screw terminals 47, 48 each containing two input terminals 40A, 40A) or two output terminals (42A, 42A), are provided on right and left both end sides of the printed circuit board 46.

As a result thereof, the output amplifier 30 is not soldered to the low pass filter 40 but is screwed thereon (or inserted thereto). The low pass filter 40 is also not soldered to the connection lines La, Lb which connect the speaker WF but is mechanically screwed thereon.

As a result thereof, the low pass filter 40 shown in FIG. 2 is configured so that the iron-core coil 43 and the capacitor 44 (both are electronics parts) are soldered on the printed circuit board 46 with a total of four points using solder (audio solder alloy), as shown as black dots in FIG. 2. Numbers of soldered points are counted including soldering on a lead line of the electronics parts. In fact, since two input terminal portions and two output terminal portions are respectively soldered on the printed circuit board (circuit board), a total of eight points are soldered in this embodiment.

The reason why the screw (insert) terminals 47, 48 are used as the terminals is because plural filter circuits NW, which will be described later, are easily exchanged to listen to and compare them.

FIG. 4 shows an example of the high pass filter 50 which is constituted of a parallel circuit of a capacitor 53 and an iron-core coil 54. The capacitor 53 having a withstand voltage of 250 V (DC) and 6.8 μF is used. As the iron-core coil 54, a coil having a diameter of 1.0 mmØ is used in this embodiment. The coil having inductance value of 0.4 mH is used.

Terminals 52A and the speaker for high range reproduction TW are respectively connected by the connection lines Lc, Ld. A pair of attenuation resistances 56, 58 are connected in series between a side of the terminal 52A and a terminal 56a and a terminal 56b is led from a middle connection point thereof. The terminals 56a, 56b are used for attenuation of the output signal depending on the situation.

This high pass filter 50 also actually utilizes a printed circuit board 66, as shown in FIG. 4, on a surface of which the capacitor 53 and the iron-core coil 54 are arranged with them having a shown positional relationship. Screw terminals 67, 68 each having two input terminals (50A, 50A) or four output terminals (52A, 52A, 56a, 56b), are provided on right and left both end sides of the printed circuit board 66. As a result thereof, the output amplifier 30 is not soldered to the high pass filter 50 but is screwed thereon (or inserted thereto). The high pass filter 50 is also not soldered to the speaker TW, but is mechanically screwed on the connection lines Lc, Ld.

As a result thereof, the high pass filter 50 shown in FIG. 4 is configured so that the capacitor 53 and the iron-core coil 54 (both are electronics parts) are soldered on the printed circuit board 66 with a total of four points using solder (audio solder alloy), as shown as black dots in FIG. 4. In fact, since two input terminal points and two output terminal points are respectively soldered on the printed circuit board (circuit board), a total of eight points are soldered in this embodiment

The reason why the screw (insert) terminals 67, 68 are used as the terminals is because plural filter circuits NW, which will be described later, are easily exchanged to listen to and compare them.

(4) Specification of Audio Solder Alloys to be used as Auditory Test

The audio solder alloy to be now used for auditory assessment contains metal (of Sn.Ag.Cu) (metal elements) as the base thereof and a trace of Pb, as described above, in addition to two optional species of elements among In, Ni, Sb, Bi, Fe and As as a trance of added metal.

In order to enhance auditory assessment accuracy and find out better audio solder alloy, in the following examples, four species of metal elements (of Sn.Ag.Cu.Pb) are selected as the base among the above-mentioned 10 species of metal (of Sn.Ag.Cu.Pb.In.Ni.Sb.Bi.Fe.As) and two species of metal are optionally extracted from the remaining (six species) of metal so that the audio solder alloy (senary solder alloy) is made of a set of six species of metals.

Further, even when they have the same composition metals, by changing their contained amounts (amounts of addition), a set of nine species of the audio solder alloys is prepared in this embodiment so that they are used as the joining solder for auditory assessment.

Further, a total of 15 species of the audio solder alloys in which a combination of the extracted composition metals were changed was prepared and the auditory assessment was carried out using filter circuits NW in which these audio solder alloys were used as the joining solder.

Therefore, as shown in FIG. 1, 15 species of the filter circuits NW0 through BW15 are used as the auditory assessment device 10. The identical circuits and speakers are used as other circuits and speakers. Combinations of these filter circuits NW0 through BW15 and the extracted elements are shown in Table 1.

Metal elements (of Sri.Ag.Cu.Pb) to be commonly used in the audio solder alloy are shown out of the table.

TABLE 1

SPECIES OF SOLDER

FILTER CIRCUITS
ADDED
HAVING DIFFERENT

GROUPS
NW
ELEMENTS
AMOUNTS OF ADDITION
CORRESPONDING TABLES

1
NWO_1~9
In•Ni
RESPECTIVE 9 SPECIES
TABLE 3~TABLE 5

NWO_3~8, NWO_10~12
In•Ni

TABLE 6~TABLE 8

2
NW2_1~9
Bi
Sb
RESPECTIVE 9 SPECIES
TABLE 9~TABLE 11

NW3_1~9
Fe

TABLE 12~TABLE 14

NW4_1~9
As

TABLE 15~TABLE 17

NW5_1~9
In

TABLE 18~TABLE 20

NW6_1~9
Ni

TABLE 21~TABLE 23

3
NW7_1~9
Fe
Bi
RESPECTIVE 9 SPECIES
TABLE 24~TABLE 26

NW8_1~9
As

TABLE 27~TABLE 29

NW9_1~9
In

TABLE 30~TABLE 32

NW10_1~9
Ni

TABLE 33~TABLE 35

4
NW11_1~9
As
Fe
RESPECTIVE 9 SPECIES
TABLE 36~TABLE 38

NW12_1~9
In

TABLE 39~TABLE 41

NW13_1~9
Ni

TABLE 42~TABLE 44

5
NW14_1~9
In
As
RESPECTIVE 9 SPECIES
TABLE 45~TABLE 47

NW15_1~9
Ni

TABLE 48~TABLE 50

(COMMON ELEMENTS: Sn, Ag, Cu and Pb)

(5) Optimal Audio Solder Alloys

As a result of the auditory assessment, senary solder alloy (of Sn.Ag.Cu.In.Ni.Pb) in which and a trace of lead, Pb, a trace of indium, In and a trace of nickel, Ni were added to (tin, Sn.argent, Ag.copper, Cu) and amounts of addition thereof were appropriately selected, had the highest auditory assessment value (the maximum value thereof is 5.0).

Specific examples thereof will be described later but it is necessary to verify whether or not the highest auditory assessment by listeners is the appropriate auditory assessment.

Higher auditory sensation assessment satisfied by improving sound quality is only assessments by the listeners so that even if assessing persons are audio specialists, variation in their assessment (auditory assessment values) arises. As one means (quantitative means) to verify whether or not the variation in their assessment was small, general sound sources, which were often used for auditory assessment, were first sampled. Items of auditory assessment were then set. Next, the auditory assessment was analyzed using multiple correlation model which utilized correlations between the auditory assessment value and the predictive (estimation or theoretical) value.

(6) Samples of Sound Sources and Items of Auditory Assessment

As the general sound sources, which were often used for auditory assessment, the following three pieces of music (on popular music, classic music and vocal) were referred. The sound source 20 in which CD had been reproduced and had been once stored was used.

(i) Vincent

(ii) Carmen ballet

(iii) Somewhere somebody

One example of items of the auditory assessment is shown in (Table 2). In this example, a total of 10 items of the auditory assessment from low range property to instrument property were performed on the basis of 5 points and their mean values were estimated as the auditory assessment values.

TABLE 2

AUDIO-VISUAL

ASSESSMENT

VALUE

ITEMS OF

(MAXIMUM

ASSESSMENT
SONG TITLES
ASSESSMENT CONTENTS
OF 5.0)

{circle around (1)}
LOW RANGE
vincent
Listen to balance of rich guitar body sound.

PROPERTY
Carmen ballet
Listen to how scale is the importance of percussion system sounds.

somewhere
Listen to volume of low pitch sound of the synthesizer.

somebody

{circle around (2)}
MIDDLE
vincent
Listen to enhanced balance of female vocal which occupies the

majority of middle range.

RANGE
Carmen ballet
Listen to unbalance of volume of wind instrument system.

PROPERTY
somewhere
Listen to whether or not male and female vocals are appropriate.

somebody

{circle around (3)}
HIGH RANGE
vincent
Listen to whether or not harmonic overtones of the guitar can be extracted.

PROPERTY
Carmen ballet
Listen to whether or not triangle's presence is properly strong.

somewhere
Listen to which husky components are too much or less in the high range of voice

of voice components.

somebody

{circle around (4)}
RENEWABILITY
vincent
Listen to whether or not the guitar sounds are clear.

Carmen ballet
Listen to whether the instruments sound vividly even when the recording is old.

somewhere
Listen to clear voice.

somebody

{circle around (5)}
DENSITY
vincent
Listen to whether or not recognition that there are many strings

of the guitar can be given.

Carmen ballet
Listen to how many number of percussion systems can be listened.

somewhere
Listen to whether instrument of each part has proper density.

somebody

{circle around (6)}
AMOUNT OF
vincent
Listen to any tones in which strings of the guitar are rubbed or snapped,

and a sound of which remains.

INFORMATION
Carmen ballet
Distinguish live performance like sounds information.

somewhere
Listen to breathing and tenderness touched a microphone.

somebody

{circle around (7)}
S/N
vincent
Listen to whether or not voice is distorted because the voice

is more strongly recorded.

Carmen ballet
Listen to whether each instrument weakly recorded is clearly heard over

any noise of equipment and audience.

somewhere
Listen to whether ot not base recorded low and richly causes upper

range to be made unharmonious.

somebody

{circle around (8)}
SOUND FIELD
vincent
Listen to voice depth and lip size.

Carmen ballet
Listen to positions of the instruments and an expanse and depth of space.

somewhere
Listen to expanse feeling of voice and instrument and their feeling of depth.

somebody

{circle around (9)}
VOCAL
vincent
Listen to smooth and vivid voice.

PROPERTY
Carmen ballet
None

somewhere
Listen to deep male voice and smooth and vivid female voice.

somebody

{circle around (10)}
INSTRUMENT
vincent
Listen to whether or not it is a sound that is near living instrument sound.

PROPERTY
Carmen ballet
Listen to whether ot not it is near a situation where instrument of live

performance sounds in a hall.

somewhere
Listen to reality and vividness of the percussion system.

somebody

AUDIO VISUAL

ASSESSMENT

VALUE

(MEAN VALUE)

(7) Analysis of Auditory Assessment

The analysis of auditory assessment is performed so that, as described above, the multiple correlation analysis is respectively performed on a set of audio solder alloy constituted of extracted senary composition alloy, each of which contains 9 species of audio solder alloy having different amounts of addition, and the same is also performed on 15 kinds of audio solder alloy constituted of different composition metals. The most multiple correlation of this multiple correlation analysis was estimated as the audio solder alloy of the highest auditory assessment (in this invention).

In the following examples, the multiple correlation analysis provided with Excel (registered trade mark) was used as an analysis tool. In this example, a main component made of (Sn.Ag.Cu) and plural species (therefore, three species) of metal elements to be added were respectively set as explanatory variables (independent variables) and it was verified with the explanatory variable being changed how much a multiple correlation equation (multiple correlation model) derived from the multiple correlation analysis reflected the auditory assessment values (measured values, namely, dependent variables (objective variables), maximum value of which is 5.0).

(8) Grouping of Audio Solder Alloys and Relation to Corresponding Tables of Multiple Correlation Analysis

When performing the multiple correlation analysis, the audio solder alloys are grouped into the ones shown in the (Table 1).

(A) Audio Solder Alloys of Group 1

The composition of the audio solder alloys of this group is [Audio solder alloys of group 1: (Sr.Ag.Cu.In.Ni.Pb)].

The corresponding tables indicating results of the multiple correlation analysis when using the audio solder alloys are shown as (Tables 3 through 5) and (Tables 6 through 8) among the combination examples of (Table 1). The (Tables 3 through 5) indicate results of the multiple correlation analysis of the audio solder alloys according to this invention.

It is to be noted that solder alloy shown in data 7 is a solder alloy which is a typical solder alloy as lead-free solder composed of almost (Sn.3AG.0.5Cu) so that the assessment has been performed on the basis of this solder alloy.

TABLE 3

Y
Cu
Ag
In
Ni
Pb
NW

EXAMPLE 1
5.00
0.7200
1.0100
0.0030
0.0160
0.0035
NWO₁

EXAMPLE 2
5.00
0.7100
1.0000
0.0037
0.0170
0.0025
NWO₂

DATA 1
4.00
0.7000
3.4900
0.0000
0.0001
0.0042
NWO₃

DATA 2
4.15
1.9800
0.2700
0.0025
0.0007
0.0130
NWO₄

DATA 3
4.35
1.9700
0.2700
0.0029
0.0007
0.0130
NWO₅

DATA 4
4.18
1.6700
4.7000
0.0000
0.0001
0.0002
NWO₆

DATA 5
3.83
0.8800
3.9800
0.0022
0.0077
0.0290
NWO₇

DATA 6
3.68
0.5200
2.9900
0.0023
0.0022
0.0250
NWO₈

DATA 7
3.00
0.5800
2.9900
0.0010
0.0057
0.0280
NWO₉

Y = AUDITORY ASSESSMENT VALUE

In the (Table 3), (this example 1) and (this example 2) indicate composition elements of the audio solder alloys according to this invention and their contained amounts (% by mass (Wt %). The auditory assessment values are dependent variables, namely, measured values and the explanatory variables are the contained amounts of Ag, Cu, In, Ni and Pb (amounts of their additions). (Table 4) and (Table 5) indicate results of the multiple correlation analysis of the audio solder alloys containing their contained amounts.

TABLE 4

SUMMARY

REGRESSION STATISTICS

MULTIPLE CORRELATION R
0.981433294

MULTIPLE DETERMINATION R2
0.963211311

CORRECTION R2
0.901896828

STANDARD ERROR
0.196582672

OBSERVED FREQUENCY
9

TABLE 5

TABLE OF ANALYSIS OF VARIANCE

DEGREE OF FREEDOM
VARIATION
VARIANCE
OBSERVED VARIANCE RATIO
SIGNIFICANT F

REGRESSION
5
3.035421315
0.6070843
15.70936056
0.023169979

RESIDUAL
3
0.115934241
0.0386447

TOTAL
8
3.151355556

UPPER

STANDARD

LOWER
UPPER
LOWER
BOUND,

COEFFICIENT
ERROR
t
P-VALUE
BOUND, 95%
BOUND, 95%
BOUND, 95%
95%

INTER-
3.63863756
0.434739723
8.3696919
0.003576532
2.255101735
5.022173385
2.255101735
5.022173385

CEPT

Ag
0.11048792
0.081812703
1.3504983
0.269697507
−0.149876613
0.370852453
−0.149876613
0.370852453

Cu
0.072138465
0.188893804
0.3818996
0.727981931
−0.529005924
0.673282854
−0.529005924
0.673282854

In
376.9303504
134.5321205
2.801787
0.067752378
−51.21089948
805.0716003
−51.21089948
805.0716003

Ni
4.65124922
22.53562479
0.2063954
0.849695835
−67.06716662
76.36966506
−67.06716662
76.36966506

Pb
−45.7281429
8.463893494
−5.402731
0.012430905
−72.66402948
−18.79225633
−72.66402948
−18.79225633

Based on (Table 3) and (Table 5), the multiple correlation equation in this case is as follows. A predictive value is estimated as y.

y=0.1104879Ag+0.072135Cu+376.93035In+4.651292Ni−45.72814Pb+3.6386376 (1)

Here, since the multiple correlation coefficient of Pb indicates minus, it is said that an amount of addition of Pb is preferably as small as possible. Pb is contained in high-purity Sn so that a trace of In and/or Ni is added to order to prevent Pb from having impact thereon as much as possible.

As shown in (Table 4), since a multiple correlation coefficient R between the predictive value y by the multiple correlation equation and actual auditory assessment value Y is [0.9814333], this is closely near (1.0) so that it is understood that they have very strong correlation.

Since the multiple determination R2 (coefficient of determination: R square) is [0.9632113] and the correction R2 (adjusted R square of coefficient of determination R2) is [0.9018968], it is understood that fitting ratio (fitting accuracy) of this multiple correlation equation y is very good.

Further, since, in the table of analysis of variance shown in (Table 5), the significant F is [0.023169979], the correlation occurs with a probability of 97.7% (=100%-2.3%) so that it is said that reliability of the multiple correlation equation y, which is calculated from the multiple correlation coefficients shown in (Table 3) and (Table 5), is considerably high.

Therefore, it is said that the auditory assessment value Y, [5.0], which is maximum assessment value, of each of the audio solder alloys of the (this example 1) and (this example 2) shown in (Table 3) is very reliable assessment value. Thus, it is understood that combination of composition elements of the audio solder alloys shown in (this example 1) and (this example 2) and their contained amounts (amounts of addition) are suitable for the joining solder which allows high sound quality and high auditory assessment value to be obtained.

In (Table 3), as preferable examples of the suitable audio solder alloys, the audio solder alloys shown within a range of (this example 1) and (this example 2) have been illustrated.

The contained amounts in this audio solder alloys are (Sn.Ag (of 1.0 through 1.01% by mass).Cu (of 0.71 through 0.72% by mass).In (of 0.003 through 0.0037% by mass).Ni (of 0.016 through 0.017% by mass).Pb (of 0.0025 through 0.0035% by mass)

The contained amounts in the audio solder alloys according to this invention are not limited thereto: They can be extended to the following region.

(Region of Contained Amounts in Audio Solder Alloys According to This Invention)

(Sn (remainder).Ag (of 0.8 through 1.20).Cu (of 0.65 through 0.75).In (of 0.002 through 0.004).Ni (of 0.01 through 0.02).Pb (=<0.005)).

On the other hand, (Table 3) indicates the auditory assessment values of items of the data 1 through the data 7 indicated as the comparison examples. Similarly, (Table 4) and (Table 5) indicate the results of the multiple correlation analysis on the auditory time when the contained amounts are changed in each of the same composition elements.

In (Table 3), when their contained amounts are set like those of the data 1 through the data 7, the auditory assessment values indicate their highest value of only (4.35) even if the audio solder alloy uses the same composition metals and it is understood that they are inferior to (this example 1) and (this example 2) as the audio solder alloy.

(Table 6) through (Table 8) classified to Group 1 will indicate the cases in which the audio solder alloys have the same composition elements but their contained amounts are changed.

The data 1 through the data 6 of (Table 6) are quite identical to the data 1 through the data 6 of the above-mentioned (Table 3) and the data 8 through the data 10 of (Table 6) are newly added thereto. Since the data 7 of (Table 3) is the referenced solder as described above, it is omitted from the assessment of (Table 6).

(Table 6) indicates the auditory assessment values Y (dependent variables as the measured values) and the explanatory variables of the data 1 through the data 6 and the data 8 through the data 10. (Table 7) and (Table 8) indicate results of the multiple correlation analysis.

TABLE 6

Y
Cu
Ag
In
Ni
Pb
NW

DATA
4.00
0.7000
3.4900
0.0000
0.0001
0.0042
NWO₃

1

DATA
4.15
1.9800
0.2700
0.0025
0.0007
0.0130
NWO₄

2

DATA
4.35
1.9700
0.2700
0.0029
0.0007
0.0130
NWO₅

3

DATA
4.18
1.6700
4.7000
0.0000
0.0001
0.0002
NWO₆

4

DATA
3.83
0.8800
3.9800
0.0022
0.0077
0.0290
NWO₇

5

DATA
3.68
0.5200
2.9900
0.0023
0.0022
0.0250
NWO₈

6

DATA
4.33
0.6900
0.0048
0.0025
0.0490
0.0320
NWO₁₀

8

DATA
4.03
0.7200
0.0120
0.0026
0.0010
0.0170
NWO₁₁

9

DATA
3.78
0.7000
0.0042
0.0016
0.0340
0.0250
NWO₁₂

10

Y = AUDITORY ASSESSMENT VALUE

TABLE 7

SUMMARY

REGRESSION STATISCTICS

MULTIPLE CORRELATION R
0.95190782

MULTIPLE DETERMINATION R2
0.9061285

CORRECTION R2
0.74967601

STANDARD ERROR
0.11929342

OBSERVED FREQUENCY
9

TABLE 8

TABLE OF ANALYSIS OF VARIANCE

DEGREE OF

OBSERVED

FREEDOM
VARIATION
VARIANCE
VARIANCE RATIO
SIGNIFICANT F

REGRESSION
5
0.412107243
0.082421449
5.791716488
0.089541617

RESIDUAL
3
0.042692757
0.014230919

TOTAL
8
0.4548

COEF-
STANDARD

LOWER
UPPER
LOWER
UPPER

FICIENT
ERROR
t
P-VALUE
BOUND, 95%
BOUND, 95%
BOUND, 95%
BOUND, 95.0%

INTER-
3.751029086
0.202480038
18.52542664
0.000343265
3.106647237
4.395410934
3.106647237
4.395410934

CEPT

Cu
−0.097330449
0.142818471
−0.681497626
0.54445154
−0.551842564
0.357181666
−0.551842564
0.357181666

Ag
0.142661943
0.060418387
2.361233895
0.099288844
−0.049616329
0.334940214
−0.049616329
0.334940214

In
547.1877181
180.8848859
3.025060471
0.056531793
−28.46871856
1122.844155
−28.46871856
1122.844155

Ni
27.44481571
7.489698162
3.664342022
0.035138447
3.609253467
51.28037795
3.609253467
51.28037795

Pb
−65.7802265
19.5597036
−3.363048227
0.043634699
−128.0279329
−3.53252007
−128.0279329
−3.53252007

It is understood from the results of the multiple correlation analysis that the results have been considerably different to each other if the same composition elements are contained but their contained amounts are changed, a detailed explanation of which will be omitted.

By the way, values the multiple correlation R thereof and the coefficient of determination R2 thereof are good but values of the adjusted R square of coefficient of determination R2 (correction R2) thereof and the significant F thereof are no good so that the predictive value y and the auditory assessment value Y are not sufficiently correlated and the auditory assessment value Y has its maximum value of only (4.33). Therefore, it is not said that they are the optimal audio solder alloy.

It is to be noted that the audio solder alloys having the same composition elements are used as the joining solder for 12 filter circuits NW (NW0₁through NW0₁₂) so that the audio solder alloy having the contained amounts shown in (this example 1) is used for the filter circuit NW0₁and the audio solder alloy having the contained amounts shown in (this example 2) is used for the filter circuit NW0₂. Similarly, in the filter circuits NW0₃through NW0₁₂, the audio solder alloys shown in the data 1 through the data 10 are used and the sound quality thereof and the auditory thereof are assessed.

(9) Auditory Assessments of Other Grouped Audio Solder Alloys

The following audio solder alloys of groups 2 through 5 will indicate items of the data, all of which indicate that the auditory assessments like (this example 1) and (this example 2) cannot be acquired.

The following will show the result thereof.

(B) Audio Solder Alloys of Group 2

Composition of the audio solder alloys of this group is the one in which Pb and Sb are common added metals and, as shown in (Table 1), “Audio solder alloy of group 2: Any one of (Bi, Fe, As, In and Ni) is added into (Sn.Ag.Cu.Sb.Pb)”. Therefore, there are 5 species of audio solder alloys.

The corresponding tables indicating the results of the multiple correlation analysis when using these audio solder alloys are (Table 9 through Table 23).

(1) (Table 9 through Table 11): The results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Sb.Bi.Pb);

(2) (Table 12 through Table 14): The results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Sb.Fe.Pb);

(3) (Table 15 through Table 17): The results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Sb.As.Pb);

(4) (Table 18 through Table 20): The results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Sb.In.Pb); and

(5) (Table 21 through Table 23): The results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Sb.Ni.Pb).

(a) The following will indicate the results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Sb.Bi.Pb): (Table 9 through Table 11).

TABLE 9

Y
Cu
Ag
Sb
Bi
Pb
NW

DATA
4.33
0.6900
0.0048
0.0045
0.0026
0.0320
NW2₁

1

DATA
4.00
0.7000
3.4900
0.0006
0.0021
0.0042
NW2₂

2

DATA
4.15
1.9800
0.2700
0.0076
0.0020
0.0130
NW2₃

3

DATA
4.35
1.9700
0.2700
0.0068
0.0022
0.0130
NW2₄

4

DATA
4.18
1.6700
4.7000
0.0160
0.0057
0.0002
NW2₅

5

DATA
4.03
0.7200
0.0120
0.0050
0.0022
0.0170
NW2₆

6

DATA
3.83
0.8800
3.9800
0.0063
0.0018
0.0290
NW2₇

7

DATA
3.78
0.7000
0.0042
0.0031
0.0021
0.0250
NW2₈

8

DATA
3.68
0.5200
2.9900
0.0150
0.0080
0.0250
NW2₉

9

Y = AUDITORY ASSESSMENT VALUE

TABLE 10

SUMMARY

REGRESSION STATISTICS

MULTIPLE CORRELATION R
0.701375

MULTIPLE DETERMINATION R2
0.491927

CORRECTION R2
−0.35486

STANDARD ERROR
0.277532

OBSERVED FREQUENCY
9

TABLE 11

TABLE OF ANALYSIS OF VARIANCE

DEGREE OF

OBSERVED

FREEDOM
VARIATION
VARIANCE
VARIANCE RATIO
SIGNIFICANT F

REGRESSION
5
0.223728426
0.04474569
0.580932794
0.722401959

RESIDUAL
3
0.231071574
0.07702386

TOTAL
8
0.4548

COEF-
STANDARD

LOWER
UPPER
LOWER
UPPER

FICIENT
ERROR
t
P-VALUE
BOUND, 95%
BOUND, 95%
BOUND, 95.0%
BOUND, 95.0%

INTER-
3.958067899
0.701294227
5.64394765
0.011007654
1.726236679
6.189899118
1.726236679
6.189899118

CEPT

Cu
0.219793095
0.396367078
0.55451905
0.617882749
−1.041623848
1.481210039
−1.041623848
1.481210039

Ag
−0.030858379
0.0710587
−0.434266
0.693433006
−0.256998877
0.195282118
−0.256998877
0.195282118

Sb
−5.751897216
72.85352207
−0.0789515
0.942042561
−237.6043193
226.1005249
−237.6043193
226.1005249

Bi
−3.834340232
158.7625802
−0.0241514
0.982248474
−509.087727
501.4190466
−509.087727
501.4190466

Pb
−3.060031169
14.36288123
−0.2130513
0.844943398
−48.76912947
42.64906713
−48.76912947
42.64906713

As being made clear from (Table 9) through (Table 11), it is difficult to say that they are the optimal audio solder alloys.

(b) The following will indicate the results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Sb.Fe.Pb): (Table 12 through Table 14).

TABLE 12

Y
Cu
Ag
Sb
Fe
Pb
NW

DATA
4.33
0.6900
0.0048
0.0045
0.0030
0.0320
NW3₁

1

DATA
4.00
0.7000
3.4900
0.0006
0.0064
0.0042
NW3₂

2

DATA
4.15
1.9800
0.2700
0.0076
0.0090
0.0130
NW3₃

3

DATA
4.35
1.9700
0.2700
0.0068
0.0057
0.0130
NW3₄

4

DATA
4.18
1.6700
4.7000
0.0160
0.0013
0.0002
NW3₅

5

DATA
4.03
0.7200
0.0120
0.0050
0.0036
0.0170
NW3₆

6

DATA
3.83
0.8800
3.9800
0.0063
0.0120
0.0290
NW3₇

7

DATA
3.78
0.7000
0.0042
0.0031
0.0001
0.0250
NW3₈

8

DATA
3.68
0.5200
2.9900
0.0150
0.0034
0.0250
NW3₉

9

Y = AUDITORY ASSESSMENT VALUE

TABLE 13

SUMMARY

REGRESSION STATISTICS

MULTIPLE CORRELATION R
0.72336

MULPTILE DETERMINATION R2
0.523249

CORRECTION R2
−0.27134

STANDARD ERROR
0.268841

OBSERVED FREQUENCY
9

TABLE 14

TABLE OF ANALYSIS OF VARIANCE

DEGREE OF

OBSERVED

FREEDOM
VARIATION
VARIANCE
VARIANCE RATIO
SIGNIFICANT F

REGRESSION
5
0.237973791
0.047594758
0.658519442
0.681927452

RESIDUAL
3
0.216826209
0.072275403

TOTAL
8
0.4548

COEF-
STANDARD

LOWER
UPPER
LOWER
UPPER

FICIENT
ERROR
t
P-VALUE
BOUND, 95%
BOUND, 95%
BOUND, 95.0%
BOUND, 95.0%

INTER-
3.862092149
0.478814033
8.065954389
0.003980884
2.3382922
5.385892099
2.3382922
5.385892099

CEPT

Cu
0.325760224
0.311802544
1.044764482
0.372903358
−0.666534632
1.318055079
−0.666534632
1.318055079

Ag
−0.001247252
0.092252081
−0.013520038
0.990061754
−0.294834545
0.292340042
−0.294834545
0.292340042

Sb
−16.56819522
30.89852322
−0.536213174
0.62902132
−114.9010863
81.76469582
−114.9010863
81.76469582

Fe
−17.54621944
39.46010712
−0.444657167
0.6866905
−143.1258915
108.0334526
−143.1258915
108.0334526

Pb
1.544433928
15.56468153
0.099226825
0.927216973
−47.9893293
51.07819715
−47.9893293
51.07819715

As being made clear from (Table 12) through (Table 14), it is difficult to say that they are the optimal audio solder alloys.

(c) The following will indicate the results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Sb.As.Pb): (Table 15 through Table 17).

TABLE 15

Y
Cu
Ag
Sb
As
Pb
NW

DATA
4.33
0.6900
0.0048
0.0045
0.0078
0.0320
NW4₁

1

DATA
4.00
0.7000
3.4900
0.0006
0.0003
0.0042
NW4₂

2

DATA
4.15
1.9800
0.2700
0.0076
0.0012
0.0130
NW4₃

3

DATA
4.35
1.9700
0.2700
0.0068
0.0013
0.0130
NW4₄

4

DATA
4.18
1.6700
4.7000
0.0160
0.0003
0.0002
NW4₅

5

DATA
4.03
0.7200
0.0120
0.0050
0.0097
0.0170
NW4₆

6

DATA
3.83
0.8800
3.9800
0.0063
0.0013
0.0290
NW4₇

7

DATA
3.78
0.7000
0.0042
0.0031
0.0035
0.0250
NW4₈

8

DATA
3.68
0.5200
2.9900
0.0150
0.0130
0.0250
NW4₉

9

Y = AUDITORY ASSESSMENT VALUE

TABLE 16

SUMMARY

REGRESSION STATISTICS

MULTIPLE CORRELATION R
0.717832

MULTIPLE DETERMINATION R2
0.515283

CORRECTION R2
−0.29258

STANDARD ERROR
0.271078

OBSERVED FREQUENCY
9

TABLE 17

TABLE OF ANALYSIS OF VARIANCE

DEGREE OF

OBSERVED

FREEDOM
VARIATION
VARIANCE
VARIANCE RATIO
SIGNIFICANT F

REGRESSION
5
0.234350822
0.046870164
0.637836323
0.692453051

RESIDUAL
3
0.220449178
0.073483059

TOTAL
8
0.4548

COEF-
STANDARD

LOWER
UPPER
LOWER
UPPER

FICIENT
ERROR
t
P-VALUE
BOUND, 95%
BOUND, 95%
BOUND, 95.0%
BOUND, 95.0%

INTER-
3.702606422
0.776490171
4.768388009
0.017520173
1.231468146
6.173744699
1.231468146
6.173744699

CEPT

Cu
0.397470694
0.498027561
0.798089753
0.4831536
−1.187475279
1.982416666
−1.187475279
1.982416666

Ag
0.010312241
0.125198746
0.082366967
0.939542714
−0.388126045
0.408750526
−0.388126045
0.408750526

Sb
−24.81544775
51.24024493
−0.484296041
0.661331582
−187.8847759
138.2538804
−187.8847759
138.2538804

As
23.56688404
61.85403615
0.381008023
0.72857809
−173.2802648
220.4140328
−173.2802648
220.4140328

Pb
−2.254793241
12.17499536
−0.185198694
0.864886566
−41.00106225
36.49147577
−41.00106225
36.49147577

As being made clear from (Table 15) through (Table 17), it is difficult to say that they are the optimal audio solder alloys.

(d) The following will indicate the results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Sb.In.Pb): (Table 18 through Table 20).

TABLE 18

Y
Cu
Ag
Sb
In
Pb
NW

DATA
4.33
0.6900
0.0048
0.0045
0.0025
0.0320
NW5₁

1

DATA
4.00
0.7000
3.4900
0.0006
0.0000
0.0042
NW5₂

2

DATA
4.15
1.9800
0.2700
0.0076
0.0025
0.0130
NW5₃

3

DATA
4.35
1.9700
0.2700
0.0068
0.0029
0.0130
NW5₄

4

DATA
4.18
1.6700
4.7000
0.0160
0.0000
0.0002
NW5₅

5

DATA
4.03
0.7200
0.0120
0.0050
0.0026
0.0170
NW5₆

6

DATA
3.83
0.8800
3.9800
0.0063
0.0022
0.0290
NW5₇

7

DATA
3.78
0.7000
0.0042
0.0031
0.0016
0.0250
NW5₈

8

DATA
3.68
0.5200
2.9900
0.0150
0.0023
0.0250
NW5₉

9

Y = AUDITORY ASSESSMENT VALUE

TABLE 19

SUMMARY

REGRESSION STATISTICS

MULTIPLE CORRELATION R
0.704657

MULTIPLE DETERMINATION R2
0.496541

CORRECTION R2
−0.34256

STANDARD ERROR
0.276269

OBSERVED FREQUENCY
9

TABLE 20

TABLE OF ANALYSIS OF VARIANCE

DEGREE OF

OBSERVED

FREEDOM
VARIATION
VARIANCE
VARIANCE RATIO
SIGNIFICANT F

REGRESSION
5
0.22582694
0.045165388
0.59175592
0.716595198

RESIDUAL
3
0.22897306
0.076324353

TOTAL
8
0.4548

COEF-
STANDARD

LOWER
UPPER
LOWER
UPPER

FICIENT
ERROR
t
P-VALUE
BOUND, 95%
BOUND, 95%
BOUND, 95.0%
BOUND, 95%

INTER-
3.94691883
0.453145327
8.71005083
0.00318548
2.504808159
5.389029501
2.504808159
5.389029501

CEPT

Cu
0.249416923
0.261029131
0.955513147
0.409809226
−0.58129427
1.080128115
−0.58129427
1.080128115

Ag
−0.038781383
0.08389479
−0.462262118
0.675356143
−0.305772049
0.228209282
−0.305772049
0.228209282

Sb
−6.209054802
24.74894649
−0.25088158
0.818107439
−84.97124811
72.55313851
−84.97124811
725.55313851

In
−32.57040065
194.3564023
−0.167580796
0.87757286
−651.0992149
585.9584136
−651.0992149
585.9584136

Pb
−0.572723382
18.4711536
−0.031006368
0.977211926
−59.35617789
58.21073113
−59.35617789
58.21073113

As being made clear from (Table 18) through (Table 20), it is difficult to say that they are the optimal audio solder alloys.

(e) The following will indicate the results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Sb.Ni.Pb): (Table 21 through Table 23).

TABLE 21

Y
Cu
Ag
Sb
Ni
Pb
NW

DATA
4.33
0.6900
0.0048
0.0045
0.0490
0.0320
NW6₁

1

DATA
4.00
0.7000
3.4900
0.0006
0.0001
0.0042
NW6₂

2

DATA
4.15
1.9800
0.2700
0.0076
0.0007
0.0130
NW6₃

3

DATA
4.35
1.9700
0.2700
0.0068
0.0007
0.0130
NW6₄

4

DATA
4.18
1.6700
4.7000
0.0160
0.0001
0.0002
NW6₅

5

DATA
4.03
0.7200
0.0120
0.0050
0.0010
0.0170
NW6₆

6

DATA
3.83
0.8800
3.9800
0.0063
0.0077
0.0290
NW6₇

7

DATA
3.78
0.7000
0.0042
0.0031
0.0340
0.0250
NW6₈

8

DATA
3.68
0.5200
2.9900
0.0150
0.0022
0.0250
NW6₉

9

Y = AUDITORY ASSESSMENT VALUE

TABLE 22

SUMMARY

REGRESSION STATISTICS

MULTIPLE CORRELATION R
0.79071

MULTIPLE DETERMINATION R2
0.625222

CORRECTION R2
0.000591

STANDARD ERROR
0.238362

OBSERVED FREQUENCY
9

TABLE 23

TABLE OF ANALYSIS OF VARIANCE

DEGREE OF

OBSERVED

FREEDOM
VARIATION
VARIANCE
VARIANCE RATIO
SIGNIFICANT F

REGRESSION
5
0.284350867
0.056870173
1.000946832
0.5348034

RESIDUAL
3
0.170449133
0.056816378

TOTAL
8
0.4548

COEF-
STANDARD

LOWER
UPPER
LOWER
UPPER

FICIENT
ERROR
t
P-VALUE
BOUND, 95%
BOUND, 95%
BOUND, 95.0%
BOUND, 95.0%

INTER-
3.894568747
0.393923908
9.886601626
0.002200702
2.640927062
5.148210432
2.640927062
5.148210432

CEPT

Cu
0.253918089
0.19695276
1.289233465
0.287725238
−0.372873494
0.880709672
−0.372873494
0.880709672

Ag
−0.016555698
0.059251008
−0.27941631
0.798081799
−0.20511885
0.172007455
−0.20511885
0.172007455

Sb
−4.306320272
20.65089523
−0.20852947
0.848171129
−70.0266855
61.41404495
−70.0266855
61.41404495

Ni
6.938791872
6.714954181
1.03333421
0.377447058
−14.43118925
28.30877299
−14.43118925
28.30877299

Pb
−8.459822294
11.90110308
−0.71084354
0.528462678
−46.33444382
29.41479923
−46.33444382
29.41479923

As being made clear from (Table 21) through (Table 23), it is difficult to say that they are the optimal audio solder alloys.

Composition of the audio solder alloys of this group is the one in which Pb and Bi are common added metals to ((Sn.Ag.Cu) and “Audio solder alloy of group 3: Any one of (Fe, As, In and Ni) is added into (Sn.Ag.Cu.Bi.Pb)”. Therefore, there are 4 species of audio solder alloys.

The corresponding tables indicating the results of the multiple correlation analysis when using these audio solder alloys are (Table 24 through Table 35).

(1) (Table 24 through Table 26): The results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Bi.Fe.Pb);

(2) (Table 27 through Table 29): The results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Bi.As.Pb);

(3) (Table 30 through Table 32): The results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Bi.In.Pb); and

(4) (Table 33 through Table 35): The results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Bi.Ni.Pb).

(a) The following will indicate the results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Bi.Fe.Pb): (Table 24 through Table 26).

TABLE 24

Y
Cu
Ag
Bi
Fe
Pb
NW

DATA
4.33
0.6900
0.0048
0.0026
0.0030
0.0320
NW7₁

1

DATA
4.00
0.7000
3.4900
0.0021
0.0064
0.0042
NW7₂

2

DATA
4.15
1.9800
0.2700
0.0020
0.0090
0.0130
NW7₃

3

DATA
4.35
1.9700
0.2700
0.0022
0.0057
0.0130
NW7₄

4

DATA
4.18
1.6700
4.7000
0.0057
0.0013
0.0002
NW7₅

5

DATA
4.03
0.7200
0.0120
0.0022
0.0036
0.0170
NW7₆

6

DATA
3.83
0.8800
3.9800
0.0018
0.0120
0.0290
NW7₇

7

DATA
3.78
0.7000
0.0042
0.0021
0.0001
0.0250
NW7₈

8

DATA
3.68
0.5200
2.9900
0.0080
0.0034
0.0250
NW7₉

9

Y = AUDITORY ASSESSMENT VALUE

TABLE 25

SUMMARY

REGRESSION STATISTICS

MULTIPLE CORRELATION R
0.720256

MULTIPLE DETERMINATION R2
0.518769

CORRECTION R2
−0.28328

STANDARD ERROR
0.270101

OBSERVED FREQUENCY
9

TABLE 26

TABLE OF ANALYSIS OF VARIANCE

DEGREE OF

OBSERVED

FREEDOM
VARIATION
VARIANCE
VARIANCE RATIO
SIGNIFICANT F

REGRESSION
5
0.235936014
0.0471872
0.646801746
0.687866766

RESIDUAL
3
0.218863986
0.0729547

TOTAL
8
0.4548

COEF-
STANDARD

LOWER
UPPER
LOWER
UPPER

FICIENT
ERROR
t
P-VALUE
BOUND, 95%
BOUND, 95%
BOUND, 95.0%
BOUND, 95.0%

INTER-
3.984314243
0.4570727
8.7170252
0.003178072
2.529704918
5.438923569
2.529704918
5.438923569

CEPT

Cu
0.244161115
0.234936321
1.0392651
0.375082845
−0.5035111111
0.99183334
−0.503511111
0.99183334

Ag
−0.010401791
0.08231119
−0.126372
0.907431733
−0.272352732
0.25154915
−0.272352732
0.25154915

Bi
−33.54779275
66.18641656
−0.506868
0.647155073
−244.1825096
117.0869241
−244.1825096
117.0869241

Fe
−16.17546652
38.78750183
−0.417028
0.704702515
−139.6146084
107.2636754
−139.6146084
107.2636754

Pb
−0.522572444
13.89523236
−0.037608
0.972362821
−44.74340334
43.69825845
−44.74340334
43.69825845

As being made clear from (Table 24) through (Table 26), it is difficult to say that they are the optimal audio solder alloys.

(b) The following will indicate the results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Bi.As.Pb): (Table 27 through Table 29).

TABLE 27

Y
Cu
Ag
Bi
As
Pb
NW

DATA
4.33
0.6900
0.0048
0.0026
0.0078
0.0320
NW8₁

1

DATA
4.00
0.7000
3.4900
0.0021
0.0003
0.0042
NW8₂

2

DATA
4.15
1.9800
0.2700
0.0020
0.0012
0.0130
NW8₃

3

DATA
4.35
1.9700
0.2700
0.0022
0.0013
0.0130
NW8₄

4

DATA
4.18
1.6700
4.7000
0.0057
0.0003
0.0002
NW8₅

5

DATA
4.03
0.7200
0.0120
0.0022
0.0097
0.0170
NW8₆

6

DATA
3.83
0.8800
3.9800
0.0018
0.0013
0.0290
NW8₇

7

DATA
3.78
0.7000
0.0042
0.0021
0.0035
0.0250
NW8₈

8

DATA
3.68
0.5200
2.9900
0.0080
0.0130
0.0250
NW8₉

9

Y = AUDITORY ASSESSMENT VALUE

TABLE 28

SUMMARY

REGRESSION STATISTICS

MULTIPLE CORRELATION R
0.711746

MULTIPLE DETERMINATION R2
0.506582

CORRECTION R2
−0.31578

STANDARD ERROR
0.2735

OBSERVED FREQUENCY
9

TABLE 29

TABLE OF ANALYSIS OF VARIANCE

DEGREE OF FREEDOM
VARIATION
VARIANCE
OBSERVED VARIANCE RATIO
SIGNIFICANT F

REGRESSION
5
0.230393673
0.0460787
0.616008495
0.703770702

RESIDUAL
3
0.224406327
0.0748021

TOTAL
8
0.4548

LOWER
UPPER
LOWER
UPPER

BOUND,
BOUND,
BOUND,
BOUND,

COEFFICIENT
STANDARD ERROR
t
P-VALUE
95%
95%
95.0%
95.0%

INTERCEPT
3.913730879
0.538068372
7.2736683
0.005363161
2.201357178
5.626104582
2.201357176
5.626104582

Cu
0.258714395
0.293812452
0.8805427
0.443400708
−0.676327955
1.193756746
−0.676327955
1.193756746

Ag
−0.009057805
0.100309444
−0.090299
0.933740998
−0.328287225
0.310171616
−0.328287225
0.310171616

Bi
−42.93504698
101.9075613
−0.421314
0.701890944
−367.2503889
281.3802949
−367.2503889
281.3802949

As
17.44700584
56.4502227
0.3090689
0.777490573
−162.2027968
197.0968085
−162.2027968
197.0968085

Pb
−4.621665739
12.16614892
−0.379879
0.729333332
−43.3397814
34.09644992
−43.3397814
34.09644992

As being made clear from (Table 27) through (Table 29), it is difficult to say that they are the optimal audio solder alloys.

(c) The following will indicate the results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Bi.In.Pb): (Table 30 through Table 32).

TABLE 30

Y
Cu
Ag
Bi
In
Pb
NW

DATA
4.33
0.6900
0.0048
0.0026
0.0025
0.0320
NW9₁

1

DATA
4.00
0.7000
3.4900
0.0021
0.0000
0.0042
NW9₂

2

DATA
4.15
1.9800
0.2700
0.0020
0.0025
0.0130
NW9₃

3

DATA
4.35
1.9700
0.2700
0.0022
0.0029
0.0130
NW9₄

4

DATA
4.18
1.6700
4.7000
0.0057
0.0000
0.0002
NW9₅

5

DATA
4.03
0.7200
0.0120
0.0022
0.0026
0.0170
NW9₆

6

DATA
3.83
0.8800
3.9800
0.0018
0.0022
0.0290
NW9₇

7

DATA
3.78
0.7000
0.0042
0.0021
0.0016
0.0250
NW9₈

8

DATA
3.68
0.5200
2.9900
0.0080
0.0023
0.0250
NW9₉

9

Y = AUDITORY ASSESSMENT VALUE

TABLE 31

SUMMARY

REGRESSION STATISTICS

MULTIPLE CORRELATION R
0.704459

MULTIPLE DETERMINATION R2
0.496263

CORRECTION R2
−0.3433

STANDARD ERROR
0.276345

OBSERVED FREQUENCY
9

TABLE 32

TABLE OF ANALYSIS OF VARIANCE

DEGREE OF FREEDOM
VARIATION
VARIANCE
OBSERVED VARIANCE RATIO
SIGNIFICANT F

REGRESSION
5
0.225700373
0.045140075
0.591097532
0.71694697

RESIDUAL
3
0.229099627
0.076366542

TOTAL
8
0.4548

LOWER
UPPER
LOWER
UPPER

STANDARD

BOUND,
BOUND,
BOUND,
BOUND,

COEFFICIENT
ERROR
t
P-VALUE
95%
95%
95.0%
95.0%

INTERCEPT
3.992375349
0.467787317
8.534595106
0.003379586
2.50366733
5.481083369
2.50366733
5.481083369

Cu
0.222015287
0.261104244
0.850293672
0.457639963
−0.608934951
1.052965525
−0.608934951
1.052965525

Ag
−0.041825509
0.07757259
−0.539178971
0.627207581
−0.288696113
0.205045094
−0.288696113
0.205045094

Bi
−13.21947567
53.41499257
−0.24748624
0.820503172
−183.2098214
156.7708701
−183.2098214
156.7708701

In
−34.49229072
192.4897954
−0.17919023
0.869207265
−647.0807287
578.0961473
−647.0807287
578.0961473

Pb
−1.100243701
18.71788857
−0.058780332
0.956823415
−60.66891902
58.46843162
−60.66891902
58.46843162

As being made clear from (Table 30) through (Table 32), it is difficult to say that they are the optimal audio solder alloys.

(d) The following will indicate the results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Bi.Ni.Pb): (Table 33 through Table 35).

TABLE 33

Y
Cu
Ag
Bi
Ni
Pb
NW

DATA
4.33
0.6900
0.0048
0.0026
0.0490
0.0320
NW10₁

1

DATA
4.00
0.7000
3.4900
0.0021
0.0001
0.0042
NW10₂

2

DATA
4.15
1.9800
0.2700
0.0020
0.0007
0.0130
NW10₃

3

DATA
4.35
1.9700
0.2700
0.0022
0.0007
0.0130
NW10₄

4

DATA
4.18
1.6700
4.7000
0.0057
0.0001
0.0002
NW10₅

5

DATA
4.03
0.7200
0.0120
0.0022
0.0010
0.0170
NW10₆

6

DATA
3.83
0.8800
3.9800
0.0018
0.0077
0.0290
NW10₇

7

DATA
3.78
0.7000
0.0042
0.0021
0.0340
0.0250
NW10₈

8

DATA
3.68
0.5200
2.9900
0.0080
0.0022
0.0250
NW10₉

9

Y = AUDITORY ASSESSMENT VALUE

TABLE 34

SUMMARY

REGRESSION STATISTICS

MULTIPLE CORRELATION R
0.79152

MULTIPLE DETERMINATION R2
0.626503

CORRECTION R2
0.004009

STANDARD ERROR
0.237954

OBSERVED FREQUENCY
9

TABLE 35

TABLE OF ANALYSIS OF VARIANCE

DEGREE OF FREEDOM
VARIATION
VARIANCE
OBSERVED VARIANCE RATIO
SIGNIFICANT F

REGRESSION
5
0.284933692
0.056986738
1.006439812
0.532826786

RESIDUAL
3
0.169866308
0.056622103

TOTAL
8
0.4548

LOWER
UPPER
LOWER
UPPER

STANDARD

BOUND,
BOUND,
BOUND,
BOUND,

COEFFICIENT
ERROR
t
P-VALUE
95%
95%
95.0%
95.0%

INTERCEPT
3.928790256
0.40707045
9.651376688
0.002361392
2.633310405
5.224270106
2.633310405
5.224270106

Cu
0.233650659
0.180818671
1.292182144
0.286829164
−0.341795054
0.809096371
−0.341795054
0.809096371

Ag
−0.017677031
0.0556983
−0.31737111
0.771767966
−0.194933881
0.159579818
−0.194933881
0.159579818

Bi
−10.38835964
44.73463571
−0.23222184
0.831305697
−152.7539358
131.9772165
−152.7539358
131.9772165

Ni
6.967044979
6.674987846
1.043753957
0.373302926
−14.27574543
28.20983539
−14.27574543
28.20983539

Pb
−8.934372075
11.41923688
−0.7823966
0.491056928
−45.27548029
27.40673614
−45.27548029
27.40673614

As being made clear from (Table 33) through (Table 35), it is difficult to say that they are the optimal audio solder alloys.

(D) Auditory Assessments of Audio Solder Alloys of Group 4

Composition of the audio solder alloys of this group is the one in which Pb and Fe are common added metals to (Sn.Ag.Cu) and “Audio solder alloy of group 4: Any one of (As, In and Ni) is added into (Sn.Ag.Cu.Fe.Pb)”. Therefore, there are 3 species of audio solder alloys.

The corresponding tables indicating the results of multiple correlation analysis when using these audio solder alloys are (Table 36 through Table 44).

(1) (Table 36 through Table 38): The results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Fe.As.Pb);

(2) (Table 39 through Table 41): The results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Fe.In.Pb); and

(3) (Table 42 through Table 44): The results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Fe.Ni.Pb).

(a) The following will indicate the results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Fe.As.Pb): (Table 36 through Table 38).

TABLE 36

Y
Cu
Ag
Fe
As
Pb
NW

DATA
4.33
0.6900
0.0048
0.0030
0.0078
0.0320
NW11₁

1

DATA
4.00
0.7000
3.4900
0.0064
0.0003
0.0042
NW11₂

2

DATA
4.15
1.9800
0.2700
0.0090
0.0012
0.0130
NW11₃

3

DATA
4.35
1.9700
0.2700
0.0057
0.0013
0.0130
NW11₄

4

DATA
4.18
1.6700
4.7000
0.0013
0.0003
0.0002
NW11₅

5

DATA
4.03
0.7200
0.0120
0.0036
0.0097
0.0170
NW11₆

6

DATA
3.83
0.8800
3.9800
0.0120
0.0013
0.0290
NW11₇

7

DATA
3.78
0.7000
0.0042
0.0001
0.0035
0.0250
NW11₈

8

DATA
3.68
0.5200
2.9900
0.0034
0.0130
0.0250
NW11₉

9

Y = AUDITORY ASSESSMENT VALUE

TABLE 37

SUMMARY

REGRESSION STATISTICS

MULTIPLE CORRELATION R
0.693926

MULTIPLE DETERMINATION R2
0.481533

CORRECTION R2
−0.38258

STANDARD ERROR
0.280356

OBSERVED FREQUENCY
9

TABLE 38

TABLE OF ANALYSIS OF VARIANCE

OBSERVED

DEGREE OF

VARIANCE

FREEDOM
VARIATION
VARIANCE
RATIO
SIGNIFICANT F

REGRESSION
5
0.219001381
0.043800276
0.557258686
0.735279628

RESIDUAL
3
0.235798619
0.07859954

TOTAL
8
0.4548

LOWER
UPPER
LOWER
UPPER

STANDARD

BOUND,
BOUND,
BOUND,
BOUND,

COEFFICIENT
ERROR
t
P-VALUE
95%
95%
95.0%
95.0%

INTERCEPT
3.984340657
0.521085175
7.646236835
0.004645279
2.326015068
5.642666245
2.326015068
5.642666245

Cu
0.195187085
0.250745532
0.778426974
0.493073238
−0.602797105
0.993171276
−0.602797105
0.993171276

Ag
−0.040242104
0.0630699
−0.638055614
0.56880506
−0.240958676
0.160474468
−0.240958676
0.160474468

Fe
−5.014308251
32.37509931
−0.154881633
0.8867483
−108.0463234
98.01770693
−108.0463234
98.01770693

As
−4.641966497
30.60183149
−0.151689173
0.889058759
−102.030652
92.74671904
−102.030652
92.74671904

Pb
−2.611872537
13.92098378
−0.187621261
0.863146273
−46.91465594
41.69091087
−46.91465594
41.69691087

As being made clear from (Table 36) through (Table 38), it is difficult to say that they are the optimal audio solder alloys.

(b) The following will indicate the results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Fe.In.Pb): (Table 39 through Table 41).

TABLE 39

Y
Cu
Ag
Fe
In
Pb
NW

DATA
4.33
0.6900
0.0048
0.0030
0.0025
0.0320
NW12₁

1

DATA
4.00
0.7000
3.4900
0.0064
0.0000
0.0042
NW12₂

2

DATA
4.15
1.9800
0.2700
0.0090
0.0025
0.0130
NW12₃

3

DATA
4.35
1.9700
0.2700
0.0057
0.0029
0.0130
NW12₄

4

DATA
4.18
1.6700
4.7000
0.0013
0.0000
0.0002
NW12₅

5

DATA
4.03
0.7200
0.0120
0.0036
0.0026
0.0170
NW12₆

6

DATA
3.83
0.8800
3.9800
0.0120
0.0022
0.0290
NW12₇

7

DATA
3.78
0.7000
0.0042
0.0001
0.0016
0.0250
NW12₈

8

DATA
3.68
0.5200
2.9900
0.0034
0.0023
0.0250
NW12₉

9

Y = AUDITORY ASSESSMENT VALUE

TABLE 40

SUMMARY

REGRESSION STATISTICS

MULTIPLE CORRELATION R
0.697162

MULTIPLE DETERMINATION R2
0.486034

CORRECTION R2
−0.37058

STANDARD ERROR
0.279137

OBSERVED FREQUENCY
9

TABLE 41

TABLE OF ANALYSIS OF VARIANCE

OBSERVED

DEGREE OF

VARIANCE

FREEDOM
VARIATION
VARIANCE
RATIO
SIGNIFICANT F

REGRESSION
5
0.221048422
0.044209684
0.567393187
0.729737614

RESIDUAL
3
0.233751578
0.077917193

TOTAL
8
0.4548

LOWER
UPPER
LOWER
UPPER

STANDARD

BOUND,
BOUND,
BOUND,
BOUND,

COEFFICIENT
ERROR
t
P-VALUE
95%
95%
95.0%
95.0%

INTERCEPT
3.958618305
0.468759753
8.444876678
0.003484906
2.466815562
5.450421049
2.466815562
5.450421049

Cu
0.236527922
0.262604572
0.900699941
0.434132128
−0.599197027
1.072252872
−0.599197027
1.072252872

Ag
−0.050493294
0.081164634
−0.62210955
0.57794728
−0.308795384
0.207808796
−0.308795384
0.207808796

Fe
−0.598901892
33.13401385
−0.01801514
0.986713836
−106.0461218
104.8483181
−106.0461218
104.8483181

In
−45.32357362
203.7490757
−0.222448
0.838249178
−693.7440667
603.0969194
−693.7440667
603.0969194

Pb
−0.314436158
18.63463213
−0.01687375
0.987596802
−59.61815231
58.98928
−59.61815231
58.98928

As being made clear from (Table 39) through (Table 41), it is difficult to say that they are the optimal audio solder alloys.

(c) The following will indicate the results of analysis of the audio solder alloy made of (Sn.Ag.Cu.Fe.Ni.Pb): (Table 42 through Table 44).

TABLE 42

Y
Cu
Ag
Fe
Ni
Pb
NW

DATA
4.33
0.6900
0.0048
0.0030
0.0490
0.0320
NW13₁

1

DATA
4.00
0.7000
3.4900
0.0064
0.0001
0.0042
NW13₂

2

DATA
4.15
1.9800
0.2700
0.0090
0.0007
0.0130
NW13₃

3

DATA
4.35
1.9700
0.2700
0.0057
0.0007
0.0130
NW13₄

4

DATA
4.18
1.6700
4.7000
0.0013
0.0001
0.0002
NW13₅

5

DATA
4.03
0.7200
0.0120
0.0036
0.0010
0.0170
NW13₆

6

DATA
3.83
0.8800
3.9800
0.0120
0.0077
0.0290
NW13₇

7

DATA
3.78
0.7000
0.0042
0.0001
0.0340
0.0250
NW13₈

8

DATA
3.68
0.5200
2.9900
0.0034
0.0022
0.0250
NW13₉

9

Y = AUDITORY ASSESSMENT VALUE

TABLE 43

SUMMARY

REGRESSION STATISTICS

MULTIPLE CORRELATION R
0.806915

MULTIPLE DETERMINATION R2
0.651112

CORRECTION R2
0.069633

STANDARD ERROR
0.229981

OBSERVED FREQUENCY
9

TABLE 44

TABLE OF ANALYSIS OF VARIANCE

DEGREE OF FREEDOM
VARIATION
VARIANCE
OBSERVED VARIANCE RATIO
SIGNIFICANT F

REGRESSION
5
0.29612592
0.05922518
1.119751578
0.494374817

RESIDUAL
3
0.15867408
0.05289136

TOTAL
8
0.4548

STANDARD

LOWER
UPPER
LOWER
UPPER

COEFFICIENT
ERROR
t
P-VALUE
BOUND, 95%
BOUND, 95%
BUND, 95.0%
BOUND, 95.0%

INTERCEPT
3.940037454
0.384960927
10.2349022
0.001988348
2.714919975
5.165154932
2.714919975
5.165154932

Cu
0.195944272
0.191531543
1.02303918
0.38158491
−0.41359458
0.805483124
−0.41359458
0.805483124

Ag
−0.030218289
0.051701845
−0.5844721
0.599951166
−0.194756635
0.134320058
−0.194756635
0.134320058

Fe
15.30211197
29.48506187
0.51897846
0.639630463
−78.53251425
109.1367382
−78.53251425
109.1367382

Ni
9.171129852
7.507332944
1.2216229
0.309089734
−14.72055413
33.06281384
−14.72055413
33.06281384

Pb
−13.49870232
13.78533095
−0.9792077
0.399689449
−57.36977786
30.37237323
−57.36977786
30.37237323

As being made clear from (Table 42) through (Table 44), it is difficult to say that they are the optimal audio solder alloys.

(E) Audio Solder Alloy of Group 5

Composition of the audio solder alloys of this group is the one in which Pb and As are common added metals to (Sn.Ag.Cu) and “Audio solder alloy of group 5: Any one of (In and Ni) is added into (Sn.Ag.Cu.As.Pb). Therefore, there are 2 species of audio solder alloys.

The corresponding tables indicating the results of multiple correlation analysis when using these audio solder alloys are (Table 45 through Table 50).

(1) (Table 45 through Table 47): The results of analysis of the audio solder alloy made of (Sn.Ag.Cu.As.In.Pb); and

(2) (Table 48 through Table 50): The results of analysis of the audio solder alloy made of (Sn.Ag.Cu.As.Ni.Pb).

(a) The following will indicate the results of analysis of the audio solder alloy made of (Sn.Ag.Cu.As.In.Pb): (Table 45 through Table 47).

TABLE 45

Y
Cu
Ag
As
In
Pb
NW

DATA
4.33
0.6900
0.0048
0.0078
0.0025
0.0320
NW14₁

1

DATA
4.00
0.7000
3.4900
0.0003
0.0000
0.0042
NW14₂

2

DATA
4.15
1.9800
0.2700
0.0012
0.0025
0.0130
NW14₃

3

DATA
4.35
1.9700
0.2700
0.0013
0.0029
0.0130
NW14₄

4

DATA
4.18
1.6700
4.7000
0.0003
0.0000
0.0002
NW14₅

5

DATA
4.03
0.7200
0.0120
0.0097
0.0026
0.0170
NW14₆

6

DATA
3.83
0.8800
3.9800
0.0013
0.0022
0.0290
NW14₇

7

DATA
3.78
0.7000
0.0042
0.0035
0.0016
0.0250
NW14₈

8

DATA
3.68
0.5200
2.9900
0.0130
0.0023
0.0250
NW14₉

9

Y = AUDITORY ASSESSMENT VALUE

TABLE 46

SUMMARY

REGRESSION STATISTICS

MULTIPLE CORRELATION R
0.697697

MULTIPLE DETERMINATION R2
0.486781

CORRECTION R2
−0.36858

STANDARD ERROR
0.278934

OBSERVED FREQUENCY
9

TABLE 47

TABLE OF ANALYSIS OF VARIANCE

DEGREE OF FREEDOM
VARIATION
VARIANCE
OBSERVED VARIANCE RATIO
SIGNIFICANT F

REGRESSION
5
0.221387933
0.044277587
0.56909123
0.728813311

RESIDUAL
3
0.233412067
0.077804022

TOTAL
8
0.4548

STANDARD

LOWER
UPPER
LOWER
UPPER

COEEFICIENT
ERROR
t
P-VALUE
BOUND, 95%
BOUND, 95%
BOUND, 95.0%
BOUND, 95.0%

INTERCEPT
3.93808035
0.56148352
7.013706029
0.005952844
2.151189196
5.724971503
2.151189196
5.724971503

Cu
0.255383127
0.386765049
0.660305598
0.556230226
−0.975475874
1.486242128
−0.975475874
1.486242128

Ag
−0.052000025
0.068909998
−0.75460784
0.505317205
−0.271302394
0.167302345
−0.271302394
0.167302345

As
2.589113616
37.80285872
0.068489889
0.949705135
−117.7164544
122.8946817
−117.7164544
122.8946817

In
−57.6269614
245.9291059
−0.23432347
0.829815338
−840.2831359
725.0292131
−840.2831359
725.0292131

Pb
0.325370583
20.8453849
0.015608759
0.988526542
−66.01394755
66.66468872
−66.01394755
66.66468872

As being made clear from (Table 45) through (Table 47), it is difficult to say that they are the optimal audio solder alloys.

(b) The following will indicate the results of analysis of the audio solder alloy made of (Sn.Ag.Cu.As.Ni.Pb): (Table 48 through Table 50).

TABLE 48

Y
Cu
Ag
As
Ni
Pb
NW

DATA
4.33
0.6900
0.0048
0.0078
0.0490
0.0320
NW15₁

1

DATA
4.00
0.7000
3.4900
0.0003
0.0001
0.0042
NW15₂

2

DATA
4.15
1.9800
0.2700
0.0012
0.0007
0.0130
NW15₃

3

DATA
4.35
1.9700
0.2700
0.0013
0.0007
0.0130
NW15₄

4

DATA
4.18
1.6700
4.7000
0.0003
0.0001
0.0002
NW15₅

5

DATA
4.03
0.7200
0.0120
0.0097
0.0010
0.0170
NW15₆

6

DATA
3.83
0.8800
3.9800
0.0013
0.0077
0.0290
NW15₇

7

DATA
3.78
0.7000
0.0042
0.0035
0.0340
0.0250
NW15₈

8

DATA
3.68
0.5200
2.9900
0.0130
0.0022
0.0250
NW15₉

9

Y = AUDITORY ASSESSMENT VALUE

TABLE 49

SUMMARY

REGRESSION STATISTICS

MULTIPLE CORRELATION R
0.798603

MULTIPLE DETERMINATION R2
0.637767

CORRECTION R2
0.034044

STANDARD ERROR
0.234339

OBSERVED FREQUENCY
9

TABLE 50

TABLE OF ANALYSIS OF VARIANCE

DEGREE OF FREEDOM
VARIATION
VARIANCE
OBSERVED VARIANCE RATIO
SIGNIFICANT F

REGRESSION
5
0.290056234
0.058011247
1.056390442
0.515341233

RESIDUAL
3
0.164743766
0.054914589

TOTAL
8
0.4548

STANDARD

LOWER
UPPER
LOWER
UPPER

COEFFICIENT
ERROR
t
P-VALUE
BOUND, 95%
BOUND, 95%
BOUND, 95.0%
BOUND, 95.0%

INTERCEPT
3.80317667
0.463759539
8.200751356
0.00379435
2.327286838
5.279066502
2.327286838
5.279066502

Cu
0.287776042
0.220168696
1.307070658
0.282349128
−0.41289901
0.988451093
−0.41289901
0.988451093

Ag
−0.01341697
0.05598541
−0.23965119
0.82604153
−0.191581532
0.164753591
−0.191587532
0.164753591

As
10.39398473
26.93738756
0.385857192
0.725338725
−75.33280476
96.12077423
−75.33280476
96.12077423

Ni
8.362627901
7.256092293
1.152497455
0.332618527
−14.72949621
31.45475201
−14.72949621
31.45475201

Pb
−10.82235046
11.97987396
−0.90337766
0.432914067
−48.94765607
27.30295516
−48.94765607
27.30295516

As being made clear from (Table 48) through (Table 50), it is difficult to say that they are the optimal audio solder alloys.

The above-mentioned groups 2 through 5 relate to sound quality and auditory assessments of the audio solder alloys which are obtained by adding any optional 2 species of metals among (Bi, Fe, As, In and Ni) excluding a pair of (In, Ni) into (Sn.Ag.Cu.Sb.Pb) and the senary audio solder alloys made of these combinations cannot obtain any excellent sound quality and high auditory assessment values as indicated in (Table 9) through (Table 50).

As described above, according to this invention, as the joining solder used for the filter circuit or the like, an electronic circuit of which is configured by soldering discrete parts on the printed circuit board (circuit board), the audio solder alloys which contain the senary solder alloy, (Sn.Ag.Cu.Sb.In.Ni.Pb), as shown in group 1 and have their appropriate contained amounts have been developed to acquire excellent sound quality and high auditory assessment.

The auditory assessment device 10 shown in FIG. 1 is one example, and a three-way auditory assessment device may perform the auditory assessment.

Although the flux cored solder has been used as the audio solder alloy, this invention is not limited thereto: Solder ball, solder paste or the like may be used. Configuration and shape thereof are not limited. Further, in the soldering method, any methods using a reflow furnace, a jet solder bath or the like may be used. Further, although the description has been performed using the discrete parts as electronics parts, chip typed electronics parts may be used.

Additionally, in the above-mentioned examples, as the solder for joining the electronics parts, it has been applied to the filter circuit, but the audio solder alloy according to the invention are applicable as the solder for connecting the electronics parts constituting whole of audio system, If so, further improved sound quality may be expected.

INDUSTRIAL APPLICABILITY

The audio solder alloy according to the invention is applicable for the joining solder which is used for soldering various kinds of electronics parts used for audio system on the printed circuit board (circuit board).

EXPLANATION OF REFERENCE NUMBERS

10: auditory assessment device

20: sound source

30: output amplifier

NW0 through NW15: filter circuits

40: low pass filter

50: high pass filter

WF, TW: speakers

AUDIO SOLDER ALLOY

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