KR20120108034A - Cleaning method and cleaning device used in said cleaning method - Google Patents

Abstract

The cleaning method of the present invention includes a washing step of washing a to-be-washed object, and the washing step is a dipping step of dipping a to-be-cleaned object with a flux residue in a cleaning composition having a specific composition contained in a pressure-adjustable cleaning tank (first Step), a pressure reduction step (second step) in which the pressure in the cleaning tank is P ₁ (kPa), and the pressure in the cleaning tank reduced in the pressure reduction step is P ₁ ± 0.4 (kPa), and the cleaning composition in the cleaning tank. The pressure reduction step (third step) for continuously maintaining the temperature at 50 to 70 ° C. for 8 to 16 seconds, and the step for increasing the pressure in the washing tank to P ₂ (kPa) after the pressure reduction step (fourth step) Step), the second step to the fourth step is carried out for 10 to 220 seconds.

Description

CLEANING METHOD AND CLEANING DEVICE USED IN SAID CLEANING METHOD}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for cleaning an object to be cleaned with flux residues, a method for producing an electronic component using the cleaning method, and a cleaning apparatus for use in the cleaning method.

Conventionally, as a cleaning composition of the to-be-cleaned object with a flux residue, the composition containing a glycol ether type compound and an amine compound (refer patent document 1, 2, etc.), and the composition further containing surfactant (patent document 3,4) And the like) are known.

In addition, the cleaning method for removing the abrasives attached to the wrist watch parts or the like, although not the cleaning method of the object to be cleaned with the flux residue, is a cleaning method in which a plurality of alternating operations of increasing and decreasing the pressure around the cleaning liquid are performed. Patent document 5) discloses a method for cleaning a part having a gap such as a fine closed hole, and a pressure swing cleaning method of repeatedly performing pressure reduction and atmospheric pressure in a liquid tank (see Patent Document 6, etc.). It is.

In the washing | cleaning method of patent document 5, the solvent naphtha type washing | cleaning liquid is used as a cleaning composition, for example. In the washing | cleaning method of patent document 6, the diluent liquid of surfactant is used as a washing | cleaning composition, the inside of a liquid tank is pressure-reduced to a desired pressure, and then a control valve is switched immediately and the inside of a liquid tank returns to normal pressure.

Japanese Patent Laid-Open No. 9-87668 JP 2009-41094 A Japanese Patent Laid-Open No. 4-57897 Japanese Patent Laid-Open No. 3-227400 Japanese Patent Laid-Open No. 2001-170577 Japanese Patent Laid-Open No. 6-296940

In the manufacturing process of an electronic component such as a semiconductor device, when a component (for example, a semiconductor chip, a chip capacitor, or another circuit board) is mounted on a circuit board, a space (gap) is formed between the circuit board and the component. It may become. The solder used for mounting the component includes flux. If the flux remains in the gap as a residue after soldering for a long period of time, migration may occur and cause a short between electrodes.

BACKGROUND ART With the miniaturization and densification of electronic components, a semiconductor chip mounting method using solder bumps such as a flip chip method has been widely used, and higher reliability is required for mounting. Therefore, the importance of flux residue cleaning is becoming more important in the manufacture of electronic components.

However, with the miniaturization and densification of electronic components, the gap becomes narrower. Flux residue in such a narrow gap is difficult to remove, and as a result, a problem arises in that the productivity of electronic components is lowered. Therefore, it is desired to develop a cleaning method having good removal of flux residues remaining in narrow gaps.

The present invention provides a method for cleaning a to-be-cleaned object having a flux residue, which has not only high cleaning ability to flux residues present in a narrow gap but also good rinsing with water and bubbles are suppressed, and an electronic component using the cleaning method. It provides a method of manufacturing.

The washing | cleaning method of the to-be-cleaned object with a flux residue of this invention includes the washing | cleaning process which wash | cleans the to-be-cleaned object with a flux residue using the cleaning composition. In the cleaning step, an immersion step (first step) of immersing a to-be-cleaned object having a flux residue in the cleaning composition accommodated in a cleaning tank that can be adjusted in pressure (first step), and the pressure in the cleaning tank, A pressure reduction step (second step) for depressurizing to a pressure P ₁ (kPa) satisfying 1), and the pressure in the cleaning tank depressurized in the depressurization step to P ₁ ± 0.4 (kPa); After passing through the reduced pressure holding process (third process) which keeps the temperature of a cleaning composition at 50-70 degreeC for 8 to 16 second continuously, and the said reduced pressure holding process, the pressure in the said washing tank satisfy | fills following formula (2) And a boosting step (fourth step) of using a pressure P ₂ (kPa). The second step to the fourth step is performed for 10 to 220 seconds.

0.1 (kPa) ≤P ₁ ≤7 (kPa) (1)

50 (kPa) ≤P ₂ ≤120 (kPa) (2)

The cleaning composition comprises at least 2% by weight of water (component A) and at most 10% by weight, at least 50% by weight of glycol ether (component B) and less than 97.75% by weight, and at least 5% by weight of amine compound (component C). It includes below.

The said component B is represented by following General formula (1).

R^One-O- (EO)_m-R² (One)

In General Formula (1), R ¹ is an alkyl group having 1 to 6 carbon atoms, R ² is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, EO is an oxyethylene group, m represents an average added mole number of EO, and 2 ≦ m ≤ 3 is satisfied.

The said component C is represented by following General formula (2).

In Formula (2), R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, EO is an oxyethylene group, p and q each represent an average added mole number of EO, and 1 ≦ p + q ≦ 4. Satisfies.

The method for manufacturing an electronic component including the solder bump of the present invention includes the steps of forming a solder bump on the substrate of the electronic component by using a solder flux including flux, and the method of cleaning the object to be cleaned of the present invention. And washing the flux residue derived from the flux.

The cleaning device of the present invention is a cleaning device used in the cleaning method of the object to be cleaned of the present invention,

The moisture control mechanism for making content of the said water (component A) of the said cleaning composition in the said washing tank into 2 weight% or more and 10 weight% or less is provided.

In the present invention, certain detergent compositions are used. In addition, a series of processes including the depressurization step, the depressurization step, and the step-up step in this order are performed as one cycle, and this cycle is carried out within a specific time, so that the physical force generated due to the pressure change and the cleaning agent during the depressurization step The physical force generated due to the boiling of the composition acts on the flux residue present in the narrow gap of the object to be cleaned. Therefore, the cleaning method of the to-be-cleaned object with the flux residue which not only has high washing | cleaning property with respect to the flux residue which exists in a narrow gap, but also the rinsing property by water is suppressed, and the solder bump using this cleaning method It can provide a method of manufacturing an electronic component comprising a.

1A is a conceptual plan view of a test piece used for evaluating the cleanliness of a cleaning composition for flux residues.
FIG. 1B is a conceptual side view of the test piece shown in FIG. 1A. FIG.
It is a schematic diagram of the washing tank which can adjust the pressure used for the foaming test of the detergent composition.
3 is a conceptual diagram of the washing apparatus used in the embodiment.

In the present invention, "flux" refers to rosin-based fluxes containing rosin or rosin derivatives mainly used for soldering. In the present invention, "soldering" includes soldering in a reflow method and a flow method. In the present invention, "solder flux" refers to a mixture of solder and flux, and "flux residue" refers to a flux-derived residue remaining on a substrate or the like after soldering using flux or solder flux. Also in the present invention "solder" includes lead (Pb) containing solder and Pb free solder.

In the present invention, "physical force generated due to boiling of the detergent composition" refers to physical force caused by convection or the like caused by boiling of water contained in the detergent composition, and "boiling of the detergent composition" means contained in the detergent composition. It means the boiling of water. Therefore, the larger the content of water in the cleaning composition, the larger the physical force, and the smaller the content of water in the cleaning composition, the smaller the physical force.

In the cleaning method of the object to be cleaned with the flux residue of the present invention (hereinafter, simply abbreviated as "cleaning method"), the content of water is 2% by weight or more, while each containing a specific amount of a specific glycol ether and a specific amine compound. Unexpectedly narrow gap by carrying out a series of steps including a decompression step, a depressurization step, and a step-up step in this order within a predetermined time using a cleaning composition of not more than% by weight, and also ensure a predetermined time while keeping the decompression holding time short. The cleaning property to the flux residue remaining in the surface is high, bubbles are suppressed, and rinsing with water is good. Moreover, when the said series of processes are made into 1 cycle and 1 cycle is repeatedly performed, the washing | cleaning property with respect to the flux residue which exists in a narrow gap becomes higher. Therefore, when the cleaning method of the present invention is used in the manufacturing process of an electronic component including solder bumps, it is expected to improve the productivity and reliability of the electronic component.

[Cleaning method of the object to be cleaned]

In the washing | cleaning method of this invention, a washing | cleaning process, a rinse process of rinsing a to-be-cleaned object using a rinse composition, and a drying process are performed in this order, for example.

[Cleansed]

Examples of the object to be cleaned in which the cleaning method of the present invention is preferably used are manufacturing intermediates including components soldered to a circuit board and the like, and include a flux residue in the gap between the circuit board and the component. The manufacturing intermediate is a manufacturing intermediate in the manufacturing process of an electronic component such as a semiconductor package or a semiconductor device. For example, semiconductor chips, chip capacitors, and other circuit boards are mounted by soldering using flux on a circuit board. It includes.

The gap in the object to be cleaned is, for example, a space formed between the circuit board and the component mounted on the circuit board by soldering, and the height (the shortest distance between the circuit board and the component) is, for example, 5 to 500. The space which is micrometer, 10-250 micrometers, or 20-100 micrometers is said. The width and depth of the gap depend on the size or spacing of the electrode (land) on the component or the circuit board to be mounted, the width being 130 to 20000 µm or 130 to 10000 µm and the depth to 130 to 25000 µm or 130 to 10000 µm.

[Washing process]

The washing step includes an immersion step (the immersion step is also referred to as a "first step") of immersing the to-be-washed object with the flux residue in a cleaning tank which will be described later contained in a pressure-adjustable cleaning tank, and the pressure in the cleaning tank is a predetermined value. The pressure reduction process (pressure reduction process is also called "the 2nd process") which reduces pressure until it reaches this, the pressure in the washing tank reduced by the pressure reduction process in the predetermined pressure range, and the temperature of the cleaning agent composition in a washing tank in the predetermined temperature range A pressure reducing step (continuous pressure holding step is also referred to as a "third step") that is held continuously for a predetermined time, and a boosting step of increasing the pressure in the cleaning tank to a predetermined value after the pressure reducing step is performed (this Process also referred to as " fourth process ").

The washing step may further include a pressure holding step (step 4a) and / or a fifth step after the boosting. Step 4a is carried out after the fourth step, and when the washing step includes the fifth step, it is carried out before the fifth step. In the 4th process, the pressure in a washing tank is hold | maintained continuously for a predetermined time within a predetermined pressure range. The fifth step is carried out after the fourth step, and when the washing step includes the fourth step, it is carried out after the fourth step. In the fifth step, a series of steps including at least the second step to the fourth step in this order are repeated 1 to 50 times.

In the washing | cleaning method of this invention, a washing | cleaning process may be performed using one washing tank, and may be performed using two or more washing tanks. For example, when performing the washing | cleaning method of this invention using one washing tank, 1st process may be repeated 1 to 50 times, without performing a 1st process in a 5th process. In addition, when performing the washing | cleaning method of this invention using two or more washing tanks, 1st-4th process may be repeated 1-50 times in a 5th process, and the number of repetitions in a 5th process is X times. In a case, you may repeat a 1st process-a 4th process Y (however, Y <X) times, and may repeat a 2nd process-a 4th process (XY) times.

In one example of the cleaning method of the present invention, a series of steps consisting of the second step to the fourth step, that is, the second step to the fourth step, is performed for 10 to 220 seconds. It is preferable to carry out for 15 to 100 seconds from a viewpoint of improving qualitatively and shortening washing time, It is more preferable to carry out for 15 to 50 seconds, It is still more preferable to carry out for 15 to 40 seconds.

(First step)

In the washing | cleaning process, the to-be-cleaned object which the flux residue adhered to is first thrown into the wash tank which accommodated the cleaning composition, and the to-be-cleaned object is immersed in the cleaning composition.

The filling amount of the cleaning composition in the cleaning tank is not particularly limited as long as the amount to be cleaned is immersed.

As a washing tank, a pressure-resistant container etc. provided with a heating means, an ultrasonic vibrator, etc. can be used, for example. The inside of the washing tank is in communication with an air pipe connected to a suction device such as a vacuum pump, and the air pipe includes a branch pipe not connected to the suction device. By opening / closing control of the switching control valve provided in this branch pipe, the inside of a washing tank can be pressure-reduced or boosted to desired pressure. An example of such a washing tank is disclosed by Unexamined-Japanese-Patent No. 6-296940, for example.

It is preferable that it is 50-70 degreeC immediately before starting pressure reduction, and, as for the temperature of the cleaning composition filled in the washing tank in a 1st process from the viewpoint of washing | cleaning improvement, it is more preferable that it is 60-70 degreeC More preferred. Specifically, the cleaning composition adjusted to 10 to 40 ° C is filled into the cleaning tank, and then heated to a temperature within the above preferred range. What is necessary is just to perform heating of a cleaning composition using the heating means with which a washing tank was equipped. The temperature of the cleaning composition is measured by a thermometer installed in the cleaning tank.

(Second Step)

Next, the pressure is reduced until the pressure in the washing tank becomes P ₁ (kPa). And P ₁ satisfies the relational expression _{0.1 (kPa) ≤P 1 ≤7 (} kPa).

In the second step, the inside of the cleaning tank is preferably 0.1 to 6 (kPa), more preferably 0.1 to 5, from the viewpoint of improving the cleaning property to the flux residue present in the narrow gap of the object to be cleaned and shortening the cleaning time. (kPa), More preferably, the pressure is reduced until reaching a pressure within the range of 0.1 to 4 (kPa).

In the second step, the detergent composition can be forced into the narrow gap by depressurization, so that the air hindering the contact between the flux residue and the detergent composition present in the narrow gap can be expelled from the gap, and is contained in the detergent composition. Dissolved gases can also be degassed. Therefore, the washing | cleaning method of this invention is suitable as a washing | cleaning method of the flux residue which entered the narrow gap.

In the second step, the depressurization time required to set the pressure in the cleaning tank to P ₁ (kPa) is determined from the viewpoint of achieving both the improvement of the cleaning property and the shortening of the cleaning time for the flux residue present in the narrow gap. It is more preferable that it is more than 1 second and less than 120 second from a pressure reduction start, It is more preferable that it is more than 1 second and less than 60 second, It is more preferable that it is more than 1 second and less than 30 second, It is further more preferable that it is more than 1 second and less than 15 second. Do.

In the second step, the depressurization speed to set the pressure in the cleaning tank to P ₁ (kPa) is 15 to 30 (kPa / s) from the viewpoint of achieving both the improvement of the cleaning property and the shortening of the cleaning time for the flux residue present in the narrow gap. It is preferable that it is 17-30 (kPa / s), and it is more preferable that it is 18-30 (kPa / s).

The temperature of the cleaning composition in the second step is a viewpoint of improving the cleaning property of the flux residue present in the narrow gap, more specifically, a viewpoint of obtaining a high physical force due to boiling of the cleaning composition and suppressing evaporation of water in the cleaning composition. That is, it is preferable that it is 50-70 degreeC like a 1st process, and it is more preferable that it is 55-70 degreeC from a viewpoint of suppressing the fall of the water in a washing tank, and suppressing the fall of the washability according to the fluctuation | variation of the composition of a cleaning composition. It is more preferable that it is 60-70 degreeC. What is necessary is just to perform heating of a cleaning composition using the heating means with which a washing tank was equipped. That is, it is preferable to maintain the said temperature of the cleaning composition adjusted to the temperature within the said preferable range in a 1st process in a 2nd process. The said temperature of the cleaning composition in a 2nd process is an average value of the temperature measured every second, for example by the thermometer installed in the washing tank. This average value can be calculated | required by the calculation formula of the average temperature of the cleaning composition in the 3rd process mentioned later.

(Third step)

Next, in the depressurization holding process, the pressure in the washing tank depressurized in the depressurizing process is continuously maintained at P ₁ ± 0.4 kPa and the temperature of the cleaning composition in the washing tank at 50 to 70 ° C for 8 to 16 seconds.

The pressure in the cleaning tank in the third step is the cleaning bath variation of the pressure in the third process in terms of for I to be 0.1 ~ 7 (kPa) with a view to maintaining a stable boiling conditions in the detergent composition, are P ₁ ± 0.3 preferably a (kPa), and, P ₁ ± 0.2 (kPa), and the more preferable, that the P ₁ ± 0.1 (kPa) is more preferred. That is, it is preferable that it is substantially constant, and, as for the pressure in a washing tank in a pressure reduction holding process, it is more preferable. On the other hand, the pressure in the washing tank is measured by a manometer.

In view of maintaining a stable boiling state of the cleaning composition in the third step, the temperature of the cleaning composition needs to be 50 to 70 ° C. when the pressure in the cleaning tank is P ₁ ± 0.4 (kPa). From the viewpoint of improving the cleaning property of the flux residue present in the gaps, when the pressure P _{1 in the} cleaning tank is 0.1 to 5 (kPa), the pressure is preferably 50 to 70 ° C, and the pressure P _{1 in the} cleaning tank is more than 5 kPa. When it is 7 kPa or less, it is preferable that it is 60-70 degreeC.

The temperature of the cleaning composition in the third step can be varied within the temperature range of 50 to 70 ℃, the fluctuation range is based on the temperature average value of the cleaning composition in the third step from the viewpoint of maintaining a stable boiling state of the cleaning composition It is preferable to be within ± 1.0 ° C, more preferably within ± 0.5 ° C, and even more preferably within ± 0.2 ° C. That is, in the washing | cleaning method of this invention, it is preferable that the temperature of the cleaning composition in a 3rd process is substantially constant, and it is more preferable that it is constant.

The temperature Ti of the cleaning composition in the third step is measured every second, for example, by a thermometer provided in the cleaning tank. The average value Tx (time average holding temperature) of the detergent composition temperature in a 3rd process can be calculated | required by the following formula.

Time average holding temperature Tx = ∑ (Ti * t _i ) / ∑ti

[The holding temperature before averaging is Ti and the time hold | maintained at the said temperature is t _i .]

In view of improving the cleaning property of the flux residue present in the narrow gap in the third step, the boiling state of the cleaning composition is required to be 8 seconds or more. In addition, from the viewpoint of achieving both the improvement of the cleaning property and the reduction of the washing time for the flux residue present in the gap, the decompression holding time (time of the third step) needs to be 16 seconds or less. Therefore, the reduced pressure holding time is 8 to 16 seconds from the viewpoint of achieving both the improvement of the cleaning property and the reduction of the cleaning time for the flux residue present in the gap, and for the same reason, 8 to 15 seconds are preferable, and 9 to 13 seconds are more preferable.

The decompression holding time is calculated from the time when the pressure in the washing tank reaches P ₁ in the second step (decompression step). In the second step, when the pressure in the cleaning tank is depressurized until it reaches 5 (kPa), for example, P ₁ is 5 (kPa), and the pressure is maintained at a time when the pressure in the cleaning tank reaches 5 (kPa). The time is measured. Even if the pressure in the washing tank rises or falls in the third step, if the value is within the range of P ₁ ± 0.4 (kPa), the pressure in the washing tank is maintained at a reduced pressure, and the reduced pressure holding time is calculated.

It is preferable to perform a 3rd process, applying an ultrasonic vibration to a cleaning composition. By removing the air present in the gap from the gap through the second step, while maintaining good contact between the flux residue and the cleaning composition, and degassing the dissolved gas in the cleaning composition, ultrasonic vibration is applied to the cleaning composition. Since the washing | cleaning property with respect to the existing flux residue improves and a washing time can be shortened, it is preferable.

The frequency of the ultrasonic wave and the energy density of the ultrasonic wave imparted to the cleaning composition in the third step are 20 to 400 kHz and 0.1 to 4.0 W / cm 2 in view of improving the cleanability of the flux residue present in the gap and suppressing damage to the object to be cleaned. It is preferable that it is 35-200 kHz and 0.2-2.0 W / cm <2>.

The provision of the ultrasonic vibration can be performed by, for example, an ultrasonic vibrator arranged in the cleaning tank.

The provision of the ultrasonic vibration to the cleaning composition in the cleaning method of the present invention is not limited only during the third step. The ultrasonic vibration imparting to the cleaning composition may be performed in at least one of the first to fifth steps. The ultrasonic vibration imparting to the cleaning composition is preferably carried out in all steps of the first step to the fifth step from the viewpoint of improving the cleanability of the flux residue present in the gap.

(Fourth step)

Next, the pressure is increased until the pressure in the washing tank reaches P ₂ (kPa). P ₂ satisfies the relationship 50≤P ₂ ≤120 (kPa).

In the fourth step, the pressure in the washing tank is preferably a pressure within the range of 50 to 102 kPa, more preferably a pressure within the range of 80 to 102 kPa, from the viewpoint of improving the cleaning property to the flux residue present in the gap. More preferably. On the other hand, the atmospheric pressure is a pressure at which neither the reduced pressure nor the pressure is particularly used, and is usually the same as atmospheric pressure and is about 1 atmosphere (101.3 (kPa)).

In the fourth step, the boosting time required to set the pressure in the cleaning tank to P ₂ (kPa) is determined from the viewpoint of achieving both the improvement of the cleaning property and the shortening of the cleaning time with respect to the flux residue present in the narrow gap. It is preferable that it is 1 second or more and within 60 second from a pressure start start, It is more preferable that it is 1 second or more and within 30 second, It is more preferable that it is 1 second or more and within 10 second.

The temperature of the cleaning composition in the fourth step is preferably the same as the temperature of the cleaning composition in the above-mentioned third step, from the viewpoint of improving the cleaning property of the flux residue present in the narrow gap, specifically, 50 to 70. It is preferable that it is ° C, and more preferably, it is the same temperature as the holding temperature in the third step. What is necessary is just to perform heating of a cleaning composition using the heating means with which a washing tank was equipped. The said temperature of the detergent composition in a 4th process is an average value of the temperature measured every second, for example by the thermometer installed in the washing tank. This average value can be calculated | required by the said calculation formula of the average temperature of the cleaning composition in a 3rd process.

(Step 4a)

The cleaning method of the present invention is carried out after the fourth step and before the fifth step, which will be described later, from the viewpoint of improving the cleaning property of the flux residue present in the narrow gap, and the pressure P ₃ in the cleaning tank is 50 to 120 (kPa). a pressure in the range of, P ₂ ± 0.4 (kPa) and equal to or P ₂ ± at a pressure greater than 0.4 (kPa) 8 ~ after boost for holding 16 seconds holding pressure step (this step is also referred to as a "second 4a process" It is preferable to further include). In particular, when ultrasonic vibration is applied to the cleaning composition in the fourth step, the cleaning method of the present invention preferably includes the fourth step from the viewpoint of improving the cleanability.

For example, when the pressure P ₂ (kPa) in the washing tank in the fourth step is lower than the normal pressure, the washing tank is opened to equilibrate the washing tank internal pressure and the washing tank external pressure, and the washing tank internal pressure and the washing tank external pressure. What is necessary is to maintain the equilibrium state of a predetermined time.

The temperature of the cleaning composition in the cleaning tank in the step 4a is 50 to 70 ° C in view of the efficiency of the repeated cleaning, especially when the pressure in the cleaning tank in the third step is P ₁ ± 0.4 (kPa). desirable. Although the temperature of the cleaning composition in a washing tank in a 4th process may fluctuate within the range of 50-70 degreeC, it is more preferable that it is the same temperature as the temperature of the cleaning composition in a 4th process. The said temperature of the cleaning composition in a 4th process is the average value of the temperature measured every second, for example by the thermometer installed in the washing tank. This average value can be calculated | required by the said calculation formula of the average temperature of the cleaning composition in a 3rd process.

The three pressure time keeping P ₃ at a pressure greater than P ₂ ± 0.4 (kPa) or or P ₂ ± 0.4 (kPa) in the range of 50 ~ 120kPa in a bath at 4a process three of the flux residues present in the gap It is preferable that it is 8-18 second, it is more preferable that it is 8-16 second, and it is still more preferable that it is 9-16 second from a viewpoint of making quality improvement and shortening a washing | cleaning time short.

When the cleaning method of the present invention includes the fourth step, when the series of steps consisting of the second step and the fourth a step is one cycle, the cleaning property and the cleaning time for the flux residue in the narrow gap are reduced. From a compatible viewpoint, it is preferable to perform said 1 cycle for 20 to 230 second, It is preferable to carry out for 25 to 110 second, It is more preferable to carry out for 25 to 60 second, It is still more preferable to carry out for 25 to 50 second .

(Step 5)

It is preferable that the washing | cleaning method of this invention includes the process (5th process) which repeats the said 2nd process-4th process 1 to 50 times further from a viewpoint of the washing | cleaning property improvement with respect to the flux residue which exists in a narrow space | gap. . What is necessary is just to perform 2nd-4th process performed repeatedly by a 5th process on the conditions similar to the said 2nd-4th process performed before a 5th process. Specifically, from the viewpoint of achieving both the improvement of the cleaning property and the reduction of the cleaning time for the flux residue present in the narrow gap, the pressure in the cleaning tank reaches a pressure within the range of 0.1 to 6 (kPa) in the second step that is repeatedly performed. It is preferable to reduce a pressure until it does, and it is preferable that the decompression time is 1 second or more and 120 second or less from a pressure reduction start, and it is preferable that the temperature of a cleaning composition is 50-70 degreeC. From the same point of view, it is preferable to maintain the pressure in the washing tank at a pressure of P ₁ ± 0.4 (kPa) in the third step that is repeatedly performed, and maintain the pressure in the washing tank at a pressure of P ₁ ± 0.1 (kPa). More preferably, the temperature of the cleaning composition is preferably 50 to 70 ° C. when the pressure in the cleaning tank is P ₁ ± 0.4 (kPa), the temperature of the cleaning composition is more preferably constant, and the reduced pressure holding time is 8 It is preferable that it is -16 second. In the same viewpoint, in the 4th process repeatedly performed, it is preferable that the pressure reached by a pressure rising is normal pressure, and it is preferable that the temperature of a cleaning composition is 50-70 degreeC.

On the other hand, when the cleaning bath is changed every time the second to fourth steps are completed, a step (first step) of immersing the object to be cleaned in the cleaning composition is further required. "The process of repeating 50 times more" can be understood as "the process of repeating the said 1st-4th process 1-50 times further." In addition, when the washing | cleaning method of this invention includes the said 4th process, it is preferable to perform a 4th process also after each 4th process performed by a 5th process. In the case where the fifth step includes the fourth step, when the second to fourth steps are repeatedly performed as one cycle, the fourth step is preferably performed after at least one repeated cycle. It is more preferable to perform the 4th process after every cycle in a 5th process from a viewpoint of making both the washing | cleaning improvement with respect to the existing flux residue and shortening of a washing time. That is, in the fifth step, it is preferable to repeat at least one cycle consisting of the second step to the fourth step 1 to 50 times, and repeating one cycle consisting of the first step to the fourth step 1 to 50 times. It is preferable to repeat 1 cycle which consists of said 2nd process-the 4th process 1-50 times.

The number of repetitions (the number of cycles in the fifth step) varies depending on the crevice shape of the object to be cleaned and the state of the flux residue, but is preferably 1 to 40 times from the viewpoint of cleaning property and productivity improvement for the flux residue present in the gap, It is more preferable that it is 2 to 35 times, and it is still more preferable that it is 3 to 30 times. By repeatedly performing the second step to the fourth step, the first step to the fourth step, or the second step to the fourth step in a short time, the physical force generated due to the pressure change and the pressure reduction maintenance step The physical force generated due to boiling of the cleaning composition is repeatedly added to the object to be cleaned. This makes cleaning of flux residues present in narrow gaps higher.

(Adjustment of water content)

In the washing | cleaning method of this invention, you may add water to the cleaning composition in a washing tank during the washing | cleaning process for washing one to-be-cleaned object. In addition, when a washing tank is continuously used to wash a plurality of objects to be cleaned, water may be added to the cleaning composition in the cleaning tank during and / or before the washing step for cleaning each of the objects to be cleaned. In the washing | cleaning method of this invention, since a washing | cleaning composition is boiled, especially content of the water in a washing | cleaning composition may be reduced while repeating 2nd process-4th process in a 5th process. Therefore, in order to suppress the fluctuation | variation of the compounding ratio of each component in the cleaning composition used by this invention, and to maintain high cleaning property, it is applied to the cleaning composition in a cleaning tank before and / or during any one of 1st process-5th process. It is preferable to add water to suppress the compositional variation of the cleaning composition.

The concentration of water in the cleaning composition before and / or during any one of the first to fifth steps is measured by a moisture meter such as a moisture sensor, and water is added to the cleaning composition in the cleaning tank based on the measured value. Supply it. In order to accurately measure the concentration of water in the detergent composition, it is preferable that the concentration of water be measured while the detergent composition is stirred by a stirrer, a circulation pump, an ultrasonic vibrator or the like.

The detector type of the moisture sensor is not particularly limited and may be, for example, a near infrared spectroscopy type, a capacitance conductivity type, or a conductivity type.

The supply of water to the cleaning composition in the cleaning tank is circulated through the cleaning composition in the sub tank having a solenoid valve connected to the cleaning tank and opened and closed according to the measured value by the moisture sensor provided in the cleaning tank, and the cleaning composition in the cleaning tank. It can carry out by making it. When the cleaning tank is used continuously to clean a plurality of objects to be cleaned, the replenishment of the water may be carried out while the other liquid is being lifted from the cleaning tank and the liquid is drawn out, for example, to transfer the objects to the rinsing tank. It is preferable to carry out before putting water into a washing tank. It is preferable that the moisture sensor is provided not only in the washing tank but also in the sub tank.

Adjustment of the water content in such a cleaning composition can be performed using the cleaning apparatus as shown in FIG. 3, for example.

As shown in FIG. 3, the cleaning apparatus includes a pressure adjusting unit (not shown) and a cleaning composition stored in the cleaning tank 11 to enable the storage of the cleaning composition to be stored therein and to adjust the pressure therein. The washing tank 11 including the moisture meter 15 which can measure the density | concentration of water, the sub tank 14 which can store a detergent composition, and the washing tank 11 and the sub tank 14 can communicate. In addition, the circulation line 18 provided with the valve 17 (for example, an solenoid valve) which opens and closes a flow path according to the measured value by the water meter 15, and the measurement by the water meter 15 is carried out. A liquid feeding part (pump etc. not shown) which circulates the detergent composition in the washing tank 11 and the detergent composition in the sub tank 14 through the circulation conduit 18 according to the value.

In the above washing apparatus, when the measured value by the water meter 15 is not within a predetermined range, the valve 17 is opened and the liquid feeding unit operates so that the concentration of water in the cleaning composition in the washing tank 11 is within a predetermined range. Until this, the cleaning composition in the sub tank 14 and the cleaning composition in the cleaning tank 11 can be circulated through the circulation conduit 18. The predetermined range is required to be 2% by weight or more and 10% by weight or less from the viewpoint of securing high detergency to the flux residue, preferably 3 to 8% by weight, and more preferably 4 to 7% by weight. . Moreover, it is preferable that the value within a predetermined range is an initial value of the water concentration of the cleaning composition in the washing tank 11.

In the washing | cleaning apparatus shown in FIG. 3, the water control mechanism consists of the circulation tank 18 provided with the sub tank 14, the water meter 15, and the valve 17. As shown in FIG. It is preferable that not only the washing tank 11 but also the sub tank 14 are equipped with the water meter 16. As shown in FIG. The cleaning apparatus includes a first rinsing tank 12 for pre-rinsing the object to be cleaned in the cleaning tank 11 and a second rinsing tank 13 for finishing rinsing. ) May be included.

In this way, when water is supplied to the cleaning composition used for cleaning the object to be cleaned, the cleaning composition can be used for cleaning other objects to be cleaned, which is economical.

(Preliminary washing)

In the washing | cleaning method of this invention, even if a washing | cleaning process further includes the process of immersing a to-be-cleaned object for a predetermined period in the cleaning composition accommodated in the cleaning tank different from the cleaning tank in which 1st process-5th process is performed before a 1st process, for example. do. The said cleaning composition may be the same as the cleaning composition mentioned later used by a 1st process-a 4th process, and may be a cleaning composition for cleaning the to-be-cleaned object with a conventionally well-known flux residue other than the cleaning composition mentioned later. It is preferable that immersion time to a cleaning composition is 1 to 10 minutes, for example.

[Rinse process]

The rinse process is a process of rinsing off contamination such as a cleaning composition, residual flux residue, or reattached flux residue attached to the object to be cleaned, and the cleaning method of the present invention does not include both the fourth and fifth processes. Thereafter, after the fourth step, if the cleaning method of the present invention includes the fourth step but does not include the fifth step, after the fourth step; if the cleaning method of the present invention includes the fifth step, after the fifth step Is done. A rinse process may be performed using one rinse tank, and may be performed using two or more rinse tanks.

A rinse process can be performed by passing through the process of the conditions similar to the 1st-4th process in the said washing process, respectively, for example, except changing a cleaning composition into a rinse composition. That is, in one example of the rinsing step, the washed object which has undergone the washing step is immersed in the rinse composition contained in the rinse bath, and then a series of steps including the depressurization step, the depressurization holding step, and the step-up step are performed in this order. The series of steps may include a step corresponding to the fourth step (pressurizing pressure holding step) in the washing step. Also in the 4th process of a rinse process, it carries out on the conditions similar to the 4a process of a washing process except changing a cleaning composition into a rinse composition. In the rinsing step, it is preferable to replace the cleaning composition used in the fifth step in the washing step with the rinse composition, and to repeat the series of steps including the depressurizing step, the depressurizing holding step, and the step-up step. It is more preferable to repeatedly carry out a series of steps including a depressurization holding step, a step-up step step, and a post-pressurization pressure holding step. The conditions such as temperature, pressure, time, number of cycles, one cycle, and ultrasonic vibration may be the same as those in the washing step in each step.

The number of repetitions of the second to fourth steps or the number of repetitions of the second to fourth a steps in the rinsing step may be appropriately determined according to the degree of contamination, and is 1 to 50 times in view of achieving both good rinsing performance and improved productivity. It is preferable, it is more preferable that it is 1-40 times, 2 to 35 times are more preferable, and 3-30 times are still more preferable. When using a plurality of rinse tanks, the sum of the number of rinses performed in each rinse tank should just be the said number.

Water, preferably ion-exchanged water, or the like is usually used as the rinse agent composition. However, depending on the degree of contamination, a diluent of the detergent composition obtained by mixing the cleaning composition described later with water, preferably ion-exchanged water, may be used. It is preferable to use. When the diluent is used as a rinse composition, the rinse process includes a rinse process using a diluent and a finish rinse process using water, preferably ion-exchanged water, as a rinse composition. The rinse process will be called a pre-rinse process. The pre-rinse step and the finish rinse step can be performed using, for example, the same washing tank as the rinsing tank used in the washing step.

The content of active ingredients other than water in the cleaning composition in the rinse composition used in the frying rinse step is not particularly limited unless contamination and / or cleaning composition remains in the object to be cleaned after the finishing rinsing step, but it is 0.0001 to 10% by weight. It is preferable that it is 0.0001-8 weight%, It is more preferable, It is still more preferable that it is 0.0001-5 weight%.

The rinse composition used in the frying rinse step may contain a cleaning composition for cleaning a to-be-cleaned object with a conventionally known flux residue other than the cleaning composition described later. In any case where the rinse agent composition described later or the above-mentioned known rinse composition is included in the rinse agent composition, the water content in the rinse agent composition is in view of improving the rinsing property of contamination such as residual flux residue or re-attached flux residue. It is preferable that it is 90-99.9999 weight%, It is more preferable that it is 92-99.9999 weight%, It is still more preferable that it is 95-99.9999 weight%.

As for the temperature of a rinse agent composition, 50-70 degreeC is preferable from a viewpoint of improving rinsing property.

Also in the rinse step, it is preferable to impart ultrasonic vibration to the rinse agent composition from the viewpoint of rinsing property improvement. When ultrasonic vibration is applied to the rinse composition in the third step of the rinse step, air present in the gap is discharged from the gap through the second step, so that the contamination and the rinse composition can be brought into good contact with each other. Since ultrasonic vibration is applied to the degassed rinse composition, the removal of contamination present in the gap is improved. Therefore, when ultrasonic vibration is applied to the rinse composition in the third step of the rinse step, shortening of the rinse time can be expected. The frequency of the ultrasonic wave and the energy density of the ultrasonic wave may be the same as those given to the cleaning composition in the third step.

[Drying process]

In the drying process performed after a rinse process, the rinse composition adhering to the surface is removed, for example, by spraying warm air on the to-be-cleaned object taken out from the rinse agent composition, and then transported in a vacuum drying container. The temperature in a vacuum drying vessel is set to 50-100 degreeC, for example, and the inside of a vacuum drying vessel is pressure-reduced to 0.1-5 (kPa). What is necessary is just to perform drying by a vacuum drying container, for example for 1 to 30 minutes.

On the other hand, in the cleaning method of the present invention, one or more pressure-adjustable cleaning processes are performed so that a cleaning process, for example, a rinsing process including a pre-rinse process and a final rinse process, and a drying process are continuously performed in this order from the viewpoint of productivity improvement. You may implement using the installation containing a tank, the rinse tank which can adjust two or more pressures, and a vacuum drying container. An example of such a facility is disclosed, for example in Japanese Patent Laid-Open No. 6-296940.

[Cleaning agent composition]

Next, the cleaning composition used for the cleaning method of the present invention will be described.

The cleaning composition in the present invention contains water (component A), specific glycol ether (component B), and specific amine compound (component C).

(Component A)

Component A consists of water, such as distilled water, ion exchange water, or ultra pure water.

The content of water in the detergent composition needs to be 2% by weight or more and 10% by weight or less from the viewpoint of ensuring high detergency to the flux residue. From the same point of view, the content of water is preferably 3 to 8% by weight, more preferably 4 to 7% by weight. desirable. In the present invention, the content of water in the cleaning composition used in the cleaning method for carrying out the reduced pressure, the maintenance of the reduced pressure state and the elevated pressure, preferably the reduced pressure, the maintenance of the reduced pressure state, and the elevated pressure is 2% by weight. At least 10% by weight is characterized in that it is in a specific range. In the present invention, the physical residue generated due to the pressure change due to the reduced pressure and the elevated pressure, and the physical force generated due to the boiling of the cleaning composition during the depressurization maintenance process, can dramatically remove the flux residue of the narrow gap, which has been difficult to remove conventionally. Can be. The content of water in the cleaning composition is determined by paying attention to the physical force generated due to boiling of the cleaning composition. If the water content is less than 2% by weight, the physical force due to boiling is insufficient, and if the content of water is more than 10% by weight, the solubility of the flux residue is inferior.

(Component B)

Component B consists of a glycol ether represented by following General formula (1).

R^One-O- (EO)_m-R₂ (One)

However, in General Formula (1), R ¹ is an alkyl group having 1 to 6 carbon atoms, R ² is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, EO is an oxyethylene group, m represents an average added mole number of EO, and ≤ m ≤ 3 is satisfied.

As for carbon number of R <^1> , 2-4 are preferable and 3-4 are more preferable from a viewpoint of ensuring high washability and high safety with respect to a flux residue.

As a specific example of component B represented by the said General formula (1), from the viewpoint of the solubility improvement with respect to the cleaning composition of the flux residue, the average of the monoalkyl type glycol ether of EO whose EO average added mole number (m) is 2, and EO Monoalkyl type glycol ether having an added mole number (m) of 3, Dialkyl type glycol ether having an average added mole number (m) of EO and Dialkyl type glycol ether having an average added mole number (m) of 3 of EO Etc. are preferable. 1 type of these glycol ethers may be used and may use 2 or more types together.

Examples of monoalkyl glycol ethers having an average added mole number (m) of EO include diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, and diethylene. Glycol monoisobutyl ether, diethylene glycol monohexyl ether, and the like.

Examples of the monoalkyl type glycol ether having an average added molar number (m) of EO include triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monoisopropyl ether, triethylene glycol monobutyl ether, and the like. Can be.

Examples of the dialkyl type glycol ether having an average added molar number (m) of EO include diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol methyl propyl ether, diethylene glycol diethyl ether, and diethylene glycol methyl. Butyl ether, diethylene glycol butyl methyl ether, diethylene glycol methyl isobutyl ether, and the like.

Triethylene glycol dimethyl ether etc. are mentioned as dialkyl type glycol ether whose average added mole number (m) of EO is three.

Among these glycol ethers, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether, di, from the viewpoint of improving safety and high water solubility and solubility of the flux residue. Ethylene glycol monohexyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monoisopropyl ether, triethylene glycol monobutyl ether, diethylene glycol butyl methyl ether, diethylene glycol methyl isobutyl ether, And at least one selected from the group consisting of triethylene glycol dimethyl ether.

The content of component B in the cleaning composition needs to be 50% by weight or more and less than 97.75% by weight from the viewpoint of improving the cleanability of the flux residue remaining in the narrow gap, and from the same point of view, it is preferably 60 or more and less than 97.75% by weight, and 80 It is more preferable that it is -97.25 weight%.

(Component C)

Component C consists of an amine compound represented by following General formula (2).

In the general formula (2), R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, EO represents an oxyethylene group, p, q each represents an average added mole number of EO, and 1 ≦ p + q ≦ 4. Satisfies.

As for carbon number of R <^3> , 1-3 are preferable from a viewpoint of the washing | cleaning property and the rinse property improvement with respect to the flux residue which remain in a clearance gap. p + q satisfy | fills 1 <= p + q <= 4, and it is more preferable to satisfy 1 <= p + q <= 3 from a viewpoint of the washing | cleaning improvement with respect to the flux residue which remains in a clearance gap.

Specific examples of the component C represented by the general formula (2) include monoethanolamine, diethanolamine, methyl diethanolamine, methyl mono, and the like in view of improving rinsing properties and improving cleanability of the flux residue remaining in the gap. Alkylolamines, such as ethanolamine and ethyl monoethanolamine, are preferable.

The content of component C in the cleaning composition needs to be 0.05% by weight or more and 5% by weight or less from the viewpoint of improving rinsing properties and improving the cleaning property of the flux residue remaining in the gap, but it is preferably 0.5 to 1.5% by weight.

It is preferable that the weight ratio (component B / component C) of component B and component C is 20-99 from a viewpoint of the washing | cleaning property improvement with respect to the flux residue which remains in a clearance gap, 94-98 are more preferable, and 95-97 are more desirable.

It is preferable that the weight ratio (component B / component A) of component B and component A is 20-99 from a viewpoint of the washing | cleaning property improvement with respect to the flux residue which remains in a clearance, 20-50 is more preferable, and 30-50 is more desirable.

It is preferable that the weight ratio {component B / [component A + component C]} of the weight of the component B and the total weight of the components A and C is 10-50 from a viewpoint of the washing | cleaning property improvement with respect to the flux residue which remains in a clearance gap, 15-35 are more preferable, and 23-33 are more preferable.

The cleaning composition may contain the following surfactant (component D).

It is preferable that content of the component D in a cleaning composition is less than 0.01 weight% from a viewpoint of foam suppression, 0.005 weight% or less is preferable from the same viewpoint, It is more preferable not to contain substantially, It is further more preferable not to contain .

Specific examples of component D include polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene carboxylic acid ester, polyoxyethylene polyoxypropylene carboxylic acid ester, polyoxyethylene polyoxypropylene copolymer and the like. And nonionic surfactants.

[Other optional ingredients]

The cleaning composition is a component in a range in which high cleaning property against a flux residue present in a narrow gap, good rinsing with water, and low foaming property, which are exhibited when cleaning the object to be cleaned using the cleaning composition, are not impaired. As amine compounds other than C, Morpholine, such as morpholine and ethyl morpholine; Piperazine, triethyldiamine, pentamethyldiethylenetriamine, tetramethylpropylenediamine, etc. may be included.

The cleaning composition is a group consisting of chelating agents, preservatives, corrosion inhibitors, fungicides, antibacterial agents, antioxidants, esters, and alcohols such as glycerin or polyethylene glycol, which are commonly used in the cleaning composition as other components. At least 1 sort (s) chosen from may be included.

The total content of the other optional components in the cleaning composition is preferably 45% by weight or less, more preferably 20% by weight or less, even more preferably 0.1% by weight or less, from the viewpoint of improving the cleanability of the flux residue remaining in the gap. Even more preferably 0.05% by weight or less.

[Method of Preparing Cleaner Composition]

The method for preparing the cleaning composition is not limited at all, and can be prepared by mixing component A, component B, and component C, and further mixing component D and / or other optional components as necessary.

Meanwhile, a container for mixing each component may be a container made of SUS, a container made of GS (glass lining), etc., and a propeller blade, pitched paddle, and max blend may be used as a solution stirring means. A stirring blade, a magnetic stirrer, etc. can be used.

10-40 degreeC is preferable and, as for the temperature of the liquid mixture in stirring, 20-30 degreeC is more preferable. As for the circumferential speed of the said stirring blade, 1-3 m / sec is preferable normally. Moreover, after putting all the components in a container, it is preferable to mix a liquid mixture for 15 minutes or more, and it is more preferable to mix for 20 minutes or more.

PH of detergent composition

Although what is necessary is just to determine pH of a cleaning composition suitably according to the kind of to-be-cleaned object, the required quality of the to-be-cleaned object, etc., 8-11 are preferable from a viewpoint of suppressing corrosion of a to-be-cleaned object, and 9-11 are more preferable.

The pH of the cleaning composition is, if necessary, inorganic acids such as nitric acid and sulfuric acid, organic acids such as oxycarboxylic acid, polyhydric carboxylic acid, aminopolycarboxylic acid and amino acid, and their metal salts, ammonium salts, ammonia, sodium hydroxide, potassium hydroxide, It can adjust by mix | blending suitably basic substance, such as an amine, by an appropriate amount.

[Manufacturing Method of Electronic Components]

The manufacturing method of the electronic component of this invention is a manufacturing method of the electronic component containing a solder bump, Comprising: The process of forming a solder bump using the solder flux on the board | substrate of an electronic component, and derived from solder flux by the cleaning method of this invention. The process of washing the flux residue of the process is included. That is, in the method for manufacturing an electronic component of the present invention, a solder intermediate is used to solder a component on a substrate and then reflow to produce a manufacturing intermediate (to-be-cleaned object) on which the component is mounted via solder bumps on the substrate. The process of obtaining and the process of wash | cleaning the flux residue derived from the solder flux which exist in the clearance gap of the said board | substrate and the said component are included by the washing | cleaning method of this invention. Solder bumps are printed by applying a paste-like solder flux onto a substrate and then heated (reflowed) to form solder bumps, or electrosol plating is applied to the openings of the resist layer formed on the substrate. A plating method of forming a solder bump by heating (reflowing) thereafter, a method of filling a paste-like solder flux into an opening of a resist layer formed on a substrate, and then heating (reflowing) to form a solder bump, It can form by the formation method of the solder bump using a conventionally well-known flux.

The "substrate" of the electronic component herein includes a semiconductor chip in which solder bumps can be formed, in addition to a circuit board, a package substrate, and the like, and examples of the electronic component include a semiconductor device including the substrate. Examples of the "component" include a semiconductor chip, a chip capacitor, and a circuit board different from the circuit board used for the "substrate". Regardless of how the solder bumps are formed, the flux residue in the space (gap) between the substrate and the component can be efficiently cleaned by washing the substrate or the like by the cleaning method of the present invention after the reflow step. By employing the cleaning method of the present invention, for example, the flux residue in a narrow gap having a height of 5 to 500 m, a width of 130 to 20000 m, and a depth of 130 to 25000 m can be obtained. It can also be easily removed.

Example

The cleaning composition of Examples 1-17 and Comparative Examples 1-23 was obtained by mix | blending and mixing each component so that it may become the composition of Table 1, Table 3, Table 5, and Table 6. The mixture liquid temperature during stirring was 25 degreeC, and the magnetic stirrer (80 mm rotor) was used for stirring the liquid mixture. The rotation speed of the magnetic stirrer was 200 rpm, and the stirring time after putting all the components in the container was 30 minutes. The pH of these detergent compositions was 10-11. PH of each cleaning composition is the value measured at 25 degreeC using the pH meter (Toa Denpako KK make, HM-30G).

The following test (1)-(6) was implemented using the obtained detergent composition. The obtained cleaning composition was filled in a washing tank (volume: 25 L) and heated to 60 ° C.

<Preparation of flux residue>

After apply | coating the cream solder (LIFSOLDER LF-204-11 by Tamurakaken) to the copper plate, these were heat-processed (250 degreeC) in nitrogen atmosphere, and the flux residue was prepared. That is, by the heat treatment, the flux in the cream solder was melted and excited by the solder metal to divide the solder metal and the flux residue. Flux residue can be observed as a brown film-like contamination on the copper plate.

<Creation of Test Piece>

As shown in FIGS. 1A and 1B, a pair of aluminum plates 2 are arranged on one main surface of a PKG substrate 1 of a commercially available micro processing unit (MPU) so that the distance W4 is 3 mm. It was arrange | positioned in parallel with each other, and the cover glass 5 was arrange | positioned on the pair of aluminum plate 2. The height W3 of the space between the cover glass 5 and the PKG substrate 1 is 50 μm. Fixing the pair of aluminum plates 2 to the PKG substrate 1 and fixing the cover glass 5 to the pair of aluminum plates 2 are carried out using an epoxy resin 3a, and the PKG The gap 17 surrounded by the board | substrate 1, a pair of aluminum plate 2, and the cover glass 5 was formed.

The flux residue prepared in <Preparation of flux residue> was taken out of the copper plate, and 0.05 g of it was placed in the vicinity of one end of the said gap 17, and these were put in 150 degreeC high temperature bath. Then, the flux residue penetrated into the gap 17 by the capillary phenomenon. Next, one end of the gap 17 was sealed with an epoxy resin 3b to obtain a test piece. On the other hand, the length in the longitudinal direction of the flux residue filled in the region 4 by capillary action was 5 mm, and the entire surface surrounding the region 4 was covered with the flux residue. In Fig. 1A, the lengths of both W1 and W2 are 5 mm, and reference numeral 6 denotes an air 굄 in which air is accumulated. The space (gap 17) surrounded by the PKG substrate 1, the pair of aluminum plates 2, the cover glass 5, and the epoxy resin 3b has a height of 50 μm, a width of 3 mm, and a depth of 10 mm.

(1) clearance cleaning test 1

Next, after setting the test piece to the jig, it was immersed in the cleaning composition (60 ° C, 5L) in the cleaning tank (volume: 25L) so that the air chuck 6 was lower than the region 4. Then the reduced pressure step of pressure until it reaches the pressure P ₁ showing the pressure in the washing tub, for the example 19kPa / s Table 1, Table 3, Table 5, and Table 6 at a rate of (Example 1 For) After roughing, the reduced pressure is maintained for the times shown in Tables 1, 3, 5, and 6 (see "Reduction Time Retention"), and then the pressure in the cleaning bath is for example 19 kPa / s (Example The pressure was increased until the pressure P ₂ shown in Table 1, Table 3, Table 5, and Table 6 was reached. If the pressure P ₂ is equal to the normal pressure (101.3 (kPa)), then the pressure in the washing tank is returned to normal pressure for the time described in Table 1, Table 3, Table 5, and Table 6 (see "Pressure holding time after boosting"). Maintained. When the pressure P ₂ was lower than the normal pressure, the pressure in the cleaning tank was maintained for the time described in Table 1, Table 3, Table 5, and Table 6 (see "Pressure holding time after boosting"). A series of processes consisting of a depressurization step, a depressurization step, a step-up step, and a post-pressurization pressure holding step were carried out as many times as described in Tables 1, 3, 5, and 6 (see "Number of cycles"). However, in Comparative Example 1, neither decompression nor boosting were performed. In addition, about Examples 16-17 and Comparative Examples 2 and 20-23, the pressure holding process after a pressure increase was not performed. In Comparative Example 13, the pressure maintaining step and the pressure holding step after the boost were not performed.

The decompression speed and the boosting speed are respectively determined by dividing the pressure difference between the initial pressure in each step and the initial pressure (predetermined pressure) in the next step by the time required to make the predetermined pressure. For example, in Example 1, since the pressure was reduced in 5 seconds from normal pressure (101.3 kPa) to 4.0 kPa, the decompression rate was 19 kPa / s (= (101.3-4.0) / 5).

The pressure in the washing tank during the depressurization step, the depressurization step, the step-up step, and the post-pressurization pressure holding step was measured by a manometer (DM-10S manufactured by Shibataka Chemical Co., Ltd.). The pressure in the washing tank was continuously monitored during each step. Further, in all the examples and comparative examples in which the pressure holding step and the pressure holding step after the pressure increase were carried out, the pressure in the cleaning tank during the pressure reducing step was in the range of P ₁ ± 0.4 (kPa), The pressure in the bath was in the range of P ₂ ± 0.4 (kPa).

The temperature of the cleaning composition in the washing tank during the depressurizing step, the depressurizing holding step, the boosting step, and the pressure holding step after the boosting, and the rinse composition described later were measured by a thermometer attached to the washing tank. The temperature of the cleaning composition in the depressurization step, the depressurization step, the step-up step and the post-pressurization pressure step was measured and monitored every second during each step, and in all the examples and the comparative examples, the temperature of the cleaning composition was within ± 0.1 ° C. I was in. For example, the temperature "60 degreeC" of the cleaning composition of Example 1 of Table 1 is a pressure reduction process (2nd process), a pressure reduction holding process (3rd process), a pressure raising process (4th process), and a pressure holding process after a pressure increase. In (4a process), it means that the average value of the temperature of a cleaning composition is 60 degreeC in all the processes. On the other hand, the temperature control of the cleaning composition in the depressurization step, the depressurization step, the step-up step, and the post-pressurization pressure holding step was controlled to a predetermined temperature by monitoring the temperature every second by a temperature control device installed in the washing tank.

Thereafter, the pre-rinse step and the finish rinse step were carried out once in this order, and the washed object washed after the finish rinse step was dried. The washing process, pre-rinse process and finish rinse process were carried out in different tanks.

In the pre-rinse process, as the rinse composition, in each of the examples and the comparative examples, except that a 5% diluent of the used detergent composition was used, the pressure-reducing step, the pressure-reducing holding step, the step-up step, and the pressure-holding pressure after the step-up were maintained under the same conditions as the washing step. The steps were carried out in this order. The cycle number is also the same as that of the corresponding washing step.

In the finishing rinse step, the depressurization step, the depressurization holding step, the step-up step, and the post-pressurization pressure hold step were carried out in this order under the same conditions as the corresponding washing step, except that water was used as the rinse agent composition. The cycle number is also the same as that of the corresponding washing step.

Also in the pre-rinse process and the finish rinse process, neither the pressure reduction nor the pressure increase were carried out in Comparative Example 1. In addition, in Examples 16-17 and Comparative Examples 2 and 20-23, the pressure holding process after a pressure increase was not performed. In Comparative Example 13, a pressure maintaining step and a pressure maintaining step after boosting were not performed.

Drying of the test piece after cleaning and rinsing is performed by removing the rinse composition adhered to the surface by spraying warm air (25 ° C.) on the test piece, and then leaving the test piece in a vacuum drying container set at 80 ° C. for 5 minutes. It was. The pressure in the vacuum drying vessel was 1.0 (kPa).

While the test piece was immersed in the cleaning composition of Examples 1 to 13, 16, and 17 and the cleaning composition of Comparative Examples 1 to 13 and 20 to 23 in crevice cleaning test 1, the cleaning composition was subjected to ultrasonic vibration (40 kHz, 1.0 W). / Cm 2) was applied continuously.

(2) Clearance test 2 (a)

The same test as in the crevice cleaning test 1 was conducted except that the energy density of the ultrasonic vibration applied to the cleaning composition was 0.5 W / cm 2. On the other hand, clearance washing test 2 (a) was performed with respect to the cleaning composition of Examples 1-13 and the cleaning composition of Comparative Examples 1-13.

(3) Clearance test 2 (b)

The same test as that in crevice cleaning test 2 (a) was carried out except that the number of cycles in the washing step was twice that in crevice cleaning test 2 (a). On the other hand, clearance washing test 2 (b) was performed with respect to the cleaning composition of Examples 1-13 and the cleaning composition of Comparative Examples 1-13.

The area of the area | region where the flux residue remain | survives in the area | region 4 seen when the test piece before and after each clearance washing | cleaning test is respectively planarly observed was observed using the optical microscope (50x magnification). The area ratio of the part from which the flux residue was removed from the area of the said area | region 4 with respect to the area of the area | region 4 visible when a test piece is respectively seen in plan view is computed as a washing | cleaning rate (percentage), and the flux on the following judgment criteria The washability of the cleaning composition with respect to the residue was evaluated.

(4) clearance cleaning test 3

The cleaning composition of Examples 14 to 15 and the cleaning compositions of Comparative Examples 14 to 19 were tested in the same manner as in the crevice cleaning test 1 except that ultrasonic vibration was not applied. However, in Comparative Example 14, neither the decompression nor the boosting were performed. In addition, about Example 14, 15 and Comparative Examples 15-19, the pressure holding process after a pressure increase was not performed.

(5) Crevice cleaning test 4 (Example 18: When adjusting the concentration of water in the cleaning composition)

As shown in FIG. 3, the test includes a cleaning tank 11 in which a cleaning process is performed, a first rinsing tank 12 in which a pre-rinse is performed, and a second rinsing tank 13 in which a finishing rinsing process is performed. A washing apparatus was used. In addition, 20 test pieces prepared in the same manner as in <Preparation of Test Pieces> were prepared.

After setting one of the 20 test pieces to the jig, the test piece was placed in the cleaning bath 11 at 60 ° C. such that the air duct 6 (see FIG. 1A) was below the area 4. ). The cleaning composition of Example 1 was used as the cleaning composition.

Under the same conditions as the above (1) crevice cleaning test 1, the depressurizing step, the depressurizing holding step, the step-up step, and the post-pressurizing pressure holding step were performed in this order. That is, the inside of the washing tank was depressurized to 4 kPa, and the depressurization state was maintained for 10 seconds, and then the pressure in the washing tank was elevated until the pressure was 101.3 kPa, and then the atmospheric pressure was maintained for 10 seconds. A series of steps including the depressurization step, the depressurization holding step, the step-up step and the post-pressurization pressure holding step were repeated 10 times. The quantity of the cleaning composition in the washing tank before starting a washing | cleaning process was 20L. One cycle consisting of the depressurization step, the depressurization holding step, the step-up step and the post-pressurization pressure holding step was performed for 30 seconds. The cleaning time is 300 seconds.

While the test piece was immersed in the cleaning composition, ultrasonic vibration (40 kHz, 1.0 W / cm 2) was continuously applied to the cleaning composition.

The test piece was taken out of the washing tank after repeating a series of steps of the pressure reducing step, the pressure maintaining step, the step-up step, and the step-up and pressure holding step 10 times. The test piece was subjected to a pre-rinse and a finish rinse once in this order under the same conditions as in the above (1) crevice cleaning test 1, and dried after passing through a finish rinse step. The pre-rinse process and the finish rinse process were performed for 300 seconds each. In the pre-rinse step, a 5% dilution solution of the cleaning composition of Example 1 was used as the rinse agent composition, and water was used as the rinse agent composition in the finish rinse step.

Next, before the test piece (second sheet) different from the test piece is introduced into the cleaning tank, the cleaning composition in the cleaning tank 11 and the cleaning composition in the sub tank 14 are circulated to clean the cleaning agent in the cleaning tank 11. The content of water in the composition was adjusted to the same concentration (5.0 wt%) as the initial value.

The water content of the cleaning composition in the cleaning tank 11 and the water content in the cleaning composition in the sub tank 14 were all measured using a capacitance type moisture meter (manufactured by Yamamoto Denki Instruments Co., Ltd., EMC-113N) 15, 16. The pre-rinse process and the finish rinse process were carried out by replacing the unused rinse composition with each test rinse. This cleaning test was conducted in the same manner to the twentieth sheet of the test piece. The number of cycles of cleaning for each test piece is 10, and the total number of cycles for a total of 20 test pieces is 200.

On the other hand, as a reference example, the same cleanability test was performed about 20 test pieces in the same manner as in Example 18 except that the water content in the cleanser composition was not adjusted. The results of this detergency test are shown in Table 7.

As Table 7 shows, when the water content in a cleaning composition is 2 to 10 weight%, high washability is obtained. In addition, when using a cleaning composition repeatedly, the water | moisture content evaporated with use can be replenished, and high cleaning property can also be maintained by maintaining the water content in a cleaning composition at 2-10 weight%.

(6) Evaluation of cleaning

<Criteria for judging flux residue detergency>

A: 90% or more cleaning rate

B: The cleaning rate is 80% or more but less than 90%

C: The cleaning rate is 70% or more but less than 80%

D: The cleaning rate is 60% or more but less than 70%

E: The cleaning rate is 50% or more but less than 60%

F: cleaning rate is less than 50%

(7) Rinsing Test

In the rinsing test, the degree of rinsing of the detergent composition entering the gap 17 between the pair of glass plates in the test piece was tested with water. However, about the test piece used for this test, the said flux 17 was not filled with the flux residue.

A test piece was prepared in which the gap 17 was filled with a detergent composition colored by methylene blue (a reagent; manufactured by Sigma Aldrich), which is a water-soluble dye. After setting the test piece to a jig so that the end side separated from the epoxy resin 3b among the lengthwise two ends of a pair of glass plates may become downward, the test piece was immersed in the rinse composition (water, 60 degreeC) in the attitude. . In the water rinsing test, the cleaning composition was changed to water, and rinsing was carried out under the same conditions as the cleaning steps (first to fifth steps) in the gap cleaning test 1 or 3.

The area of the area | region where the dye which remains when the clearance gap 17 of the test piece after a rinsing test was seen in planar view was respectively observed using the optical microscope (magnification 50x). Rinseability of the ratio of the area of the plane from which the dye is removed to the area of the plane when the gap 17 of the test piece is viewed in plan view with respect to the area of the plane when it is viewed in plan view It calculated as and evaluated the rinsing property of the cleaning composition according to the following criteria.

<Criteria for Determination of Rinseability with Water of the Cleaner Composition>

A: 90% or more rinsing

B: rinsing property is 70% or more but less than 90%

C: rinsing property is 50% or more but less than 70%

D: rinsing is less than 50%

(8) Bubble test at the time of ultrasonic vacuum pulse washing

(a) Bubble height when 2 liters of detergent compositions are put into the container 7 shown in FIG. 2, and the inside of the container 7 is pressure-reduced (5 kPa), (b) The detergent in the container 7 shown in FIG. 2 liters of the diluent (corresponding to the rinse composition for the pre-rinsing process) obtained by diluting the detergent composition with water so that the concentration of the composition was 10% by weight was added, and the height of the foam when the inside of the container 7 was decompressed (5 kPa) was visually observed. Observed by.

In Fig. 2, reference numeral 8 denotes a pressure reducing opening valve, reference numeral 10 denotes a valve for controlling opening and closing of a pipe connected to a vacuum pump, and reference numeral 9 denotes a liquid drain valve.

<Criterion for Determination of Foamability in Ultrasonic Vacuum Pulse Cleaning>

A: Bubble height is less than 10cm

B: Bubble height is less than 20cm more than 10cm

C: foam height is 20 cm or more

Table 1 - As shown in Table 6, the content of water as a detergent composition has been used to a small specific composition in 2-10 wt%, P in a range of three is 0.1 ~ 7kPa pressure in the tank to reach in a vacuum process ₁ (kPa), the pressure in the washing tank in the depressurization holding step is P ₁ ± 0.4 (kPa), and the temperature of the cleaning composition is maintained at 50 to 70 ° C for 8 to 16 seconds continuously, embodiment the pressure in conducts to voltage step-up process from a P ₂ (kPa) in the range of 50 ~ 120kPa, depressurization process 10-220 seconds in the tank examples 1 to 17 is a narrow gap than that of the comparative examples 1 to 23, the width ( The cleaning property with respect to the cleaning composition with respect to the flux residue which remains in 17) is high, and the rinse property with water is also favorable. Moreover, since the content of surfactant other than component B and the component C is 0.008 weight% or less, and the detergent composition of Examples 1-17 does not contain surfactant other than component B and the component C substantially, foam is suppressed.

In addition, the detail of each component of Table 1, Table 3, Table 5, and Table 6 is as mentioned later.

[Component B]

Diethylene glycol monobutyl ether (product of Nippon Yuka Corporation)

Triethylene glycol monobutyl ether (product of Nippon Yuka Corporation)

Diethylene glycol monohexyl ether (product of Nippon Yukazai Corporation)

Triethylene glycol dimethyl ether (product of Nippon Yuka Corporation)

[Component C]

Diethanolamine (made by Wako Pure Chemical Industries, Ltd.)

Methyl diethanolamine (product of Wako Pure Chemical Industries, Ltd.)

[Component D]

SecC _{12-14 -} O- (EO) ₇ H (nonionic surfactant, manufactured by Nihon Shokubai Co., Ltd.)

SecC _{12-14 -} O- (EO) ₇ H is a mixture of SecC ₁₂ -O- (EO) ₇ H and SecC ₁₄ -O- (EO) ₇ H.

[Optional ingredients]

Glycerin (Cao Co.)

[Etc]

Solvent naphtha (product made by Wako Pure Chemical Industries, Ltd.)

10% surfactant solution: BASF Lutensol XL-70 (10 wt% aqueous solution of nonionic surfactant)

The cleaning composition of the present invention can be suitably used for cleaning the flux residue remaining in a narrow gap.

Claims (9)

A washing step of washing a blood-washed matter having a flux residue attached thereto using a cleaning composition;
The washing step,
An immersion step (first step) of immersing the object to be cleaned with the flux residue in the cleaning composition contained in a cleaning tank that can be adjusted in pressure;
A depressurization step (second step) of depressurizing the pressure in the washing tank to a pressure P ₁ (kPa) satisfying the following formula (1);
0.1 (kPa) ≤P ₁ ≤7 (kPa) (1)
A pressure reduction maintaining step of continuously maintaining the pressure in the cleaning tank depressurized in the depressurization step at P ₁ ± 0.4 (kPa) and maintaining the temperature of the cleaning composition in the cleaning bath at 50 to 70 ° C. for 8 to 16 seconds ( The third step),
And a boosting step (fourth step) of setting the pressure P ₂ (kPa) to satisfy the following formula (2) after passing through the reduced pressure holding step,
50 (kPa) ≤P ₂ ≤120 (kPa) (2)
The second step to the fourth step is carried out for 10 to 220 seconds,
The cleaning composition,
2 wt% or more and 10 wt% or less of water (component A),
50 wt% or more but less than 97.75 wt% of a glycol ether (component B),
0.05 weight% or more and 5 weight% or less of an amine compound (component C),
The said component B is represented by following General formula (1),
R ¹ -O- (EO) _m -R ² (1)
[In General formula (1), R <^1> is a C1-C6 alkyl group, R <^2> is a hydrogen atom or a C1-C3 alkyl group, EO is an oxyethylene group, m shows the average added mole number of EO, and 2 <= m≤3 is satisfied.]
The said component C is represented by following General formula (2), The cleaning method of the to-be-cleaned object characterized by the above-mentioned.
[Formula 1]

[In General formula (2), R <^3> represents a hydrogen atom or a C1-C4 alkyl group, EO is an oxyethylene group, p and q represent the average added mole number of EO, respectively, and 1 <= p + q <= 4 Satisfies] The method of claim 1,
Further including at least the second step (the fifth step) repeating the second step to the fourth step 1 to 50 times,
The second step to the fourth step repeated in the fifth step is performed for 10 to 220 seconds each, the cleaning method of the object to be cleaned. The method according to claim 1 or 2,
After the fourth step, the pressure in the cleaning tank, a pressure in the range of _{50 ~ 120kPa, P 2 ± 0.4} (kPa) and equal to or P ₂ ± 0.4 (kPa) to more maintain 8-16 seconds at a pressure And a pressure holding step (step 4a) after the step-up. 4. The method according to any one of claims 1 to 3,
In addition, the cleaning method of the to-be-cleaned object including the rinse process of rinsing the said to-be-cleaned object with the rinse composition containing 90-99.9999 weight% of water. The method of claim 4, wherein
The said rinse process is performed by changing the said cleaning composition used at the 2nd process-the 4th process in a 5th process into the said rinse agent composition, The cleaning method of the to-be-cleaned object of Claim 1 characterized by the above-mentioned. The method according to any one of claims 1 to 5,
And said third step of said cleaning step is performed while applying ultrasonic vibration to said cleaning composition. The method of claim 5,
And a third step of the rinsing step is performed while applying ultrasonic vibration to the rinse composition. Forming a solder bump on the substrate of the electronic component using the solder flux including the flux;
The manufacturing method of the electronic component containing the solder bump containing the process of wash | cleaning the said flux residue derived from the said flux by the washing | cleaning method of the said to-be-cleaned object in any one of Claims 1-7. A washing apparatus for use in the washing method of the object to be cleaned according to any one of claims 1 to 7,
And a moisture control mechanism for setting the content of the water (component A) in the cleaning composition in the cleaning tank to 2% by weight or more and 10% by weight or less.

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