JP4508558B2 - Electronic component and its manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic component and a manufacturing method thereof, and more particularly to a ball grid array type electronic component and a manufacturing method thereof.
[0002]
[Prior art]
A circuit element, a protective film for protecting the circuit element, a circuit element terminal located at the opening of the protective film, and the circuit element terminal and a connection member are connected to one surface of the insulating substrate constituting the electronic component An electronic component having conductive balls is disclosed in US Pat. No. 6,326,677.
[0003]
[Problems to be solved by the invention]
In the manufacture of the electronic component described in the above publication, a circuit element terminal of the electronic component (hereinafter, a land-like circuit element terminal is simply referred to as “land”) and a conductive ball connected to the land are connected. New technology is required for optimization. Therefore, the problem to be solved by the present invention is to improve the product reliability of the electronic component by providing the technique.
[0004]
[Means for Solving the Problems]
(First production method of the present invention)
In order to solve the above-described problems, a first method for manufacturing an electronic component according to the present invention includes a circuit element on one surface of an insulating substrate 1 constituting the electronic component, a protective film 6 that protects the circuit element, and the protection In a method of manufacturing an electronic component having a land 8 located in an opening of a film 6 and a conductive ball 7 connected to the land 8 by a connecting member, the circuit element is placed on one surface of the insulating substrate 1 and the circuit A first step of forming the element terminal to be exposed; a second step of forming a solder layer 5 as the connecting member on the circuit element terminal by plating technique; and a protective film 6 for protecting the circuit element. A third process for forming the protective film 6 is provided so that the opening partly exposes the solder layer 5, and the first process, the second process, and the third process are performed in this order. It is characterized by that.
[0005]
(Specific description of the first production method)
An example of the first manufacturing method will be described with reference to FIG. A pair of electrodes 2 is formed on one surface of the insulating substrate 1 (FIGS. 1A and 1B). And the resistor 3 is formed so that both the electrodes 2 used as the pair may be contact | connected (FIG.1 (c)). Further, if necessary, a glass 4 film that protects the resistor 3 is formed, and the electrode 2 that becomes a circuit element terminal is exposed (FIG. 1D), thereby forming a resistor element as an example of the circuit element. The The above is the first step.
[0006]
Next, a solder layer 5 is formed on the exposed surface of the electrode 2 serving as a circuit element terminal by a plating technique (FIG. 1E). The above is the second step.
[0007]
Next, the protective film 6 is formed so that the opening of the protective film 6 that protects the resistance element partially exposes the solder layer 5 (FIG. 1F). The above is the third step.
[0008]
Thereafter, the conductive ball 7 is mounted on the land 8 (FIG. 1 (g)). Then, the solder layer 5 at the bottom of the opening of the protective film 6 is fixed through a process of melting and solidifying with the conductive ball 7 (FIG. 1 (h)). As a result, a bonding layer 12 between the solder layer 5 and the conductive ball 7 is formed. Through the above process, the first manufacturing method of the present invention is completed. For example, the electronic component of the present invention can be obtained through the above process.
[0009]
Here, the electronic component of the present invention refers to a circuit element on one surface of the insulating substrate 1 constituting the electronic component, a protective film 6 that protects the circuit element, and an opening in the protective film 6. In an electronic component having a terminal connection land 8 constituting an element and a conductive ball 7 connected to the land 8 by a connection member, a part of the solder layer 5 as the connection member formed on the surface of the land 8 The electronic component is covered with the protective film 6.
[0010]
(Reason why the first manufacturing method solves the problem)
By performing the second step before the third step, a part of the solder layer 5 formed by the plating technique is covered with the protective film 6, and the solder layer 5 is pressed against the electrode 2 surface. It will be. Then, peeling of the solder layer 5 from the electrode 2 surface hardly occurs.
[0011]
In the electronic component according to the present invention in which the conductive ball 7 and the land 8 are connected using the solder layer 5 as a connecting member, stress F from any direction is applied to the conductive ball 7 after the connection. Fateful (Figure 1 (h)). This is because the portion of the conductive ball 7 protrudes on the outer shape of the electronic component. The stress F is also applied when handling individual electronic components and after being mounted on the surface mounting circuit board surface. As a result, a large stress is concentrated at the connection portion between the conductive ball 7 and the land 8. Therefore, the connection strength of the connection portion needs to be high. According to the first manufacturing method, since the solder layer 5 can be hardly peeled off from the electrode 2 as described above, the product reliability of the electronic component is increased in that the connection strength of the connection portion is high. The problems of the present invention can be solved.
[0012]
If the second step is performed after the third step, the solder layer 5 is present only on the bottom surface of the opening of the protective film 6 as shown in FIGS. 1 (f ′) and (h ′). The protective film 6 is not in a state of pressing the solder layer 5 against the surface of the electrode 2. Therefore, it is considered that the high connection strength at the connection portion between the conductive ball 7 and the land 8 as obtained by the first manufacturing method cannot be expected.
[0013]
Thus, according to the first manufacturing method of the present invention, the product reliability of the electronic component can be increased in the sense that the connection strength can be increased, and the problem of the present invention can be solved. However, in other methods, the circuit element is formed on one surface of the insulating substrate 1 constituting the electronic component, the protective film 6 that protects the circuit element, and the opening of the protective film 6. In the electronic component having the terminal connection land 8 and the conductive ball 7 connected to the land 8 by the connection member, a part of the solder layer 5 as the connection member formed on the surface of the land 8 is It is apparent from the above-described mechanism that the problem of the present invention is solved if the electronic component is configured to be covered with the protective film 6.
[0014]
(Definition of terms in the first production method, etc.)
The “electronic component” is mainly of a so-called ball grid array type. In addition, the “circuit element” is, for example, a resistor element, a capacitor, an inductor, or a network. For example, a multiple resistor, a network resistor, a multiple capacitor, a network capacitor, or a so-called CR composite element. These circuit elements are preferably formed in a thick film by a method such as screen printing from the viewpoint of mass productivity.
[0015]
In addition, an electronic component including such a multiple element or a composite element constituting a network has a large number of terminals per unit electronic component. This means that if one of these terminals has low reliability, the entire electronic component is difficult to operate normally. Therefore, it is preferable to use the first manufacturing method of the present invention in which the product reliability is increased by increasing the connection strength of the terminal connection portion for the electronic component including these composite elements.
[0016]
The above-mentioned “insulating substrate” is particularly intended for a substrate made of ceramic such as alumina or a fiber reinforced resin and having no through hole. An electronic component in which a circuit element and a conductive ball 7 are arranged on one surface of the insulating substrate 1 using the insulating substrate 1 having no through hole uses the insulating substrate 1 having a through hole. The advantage over the electronic components in which the circuit elements and the conductive balls 7 are arranged is that they are easy to manufacture. That is, in order to form a member on both surfaces of the insulating substrate 1, fine adjustment of the alignment between the arrangement of the member on one insulating substrate 1 surface and the arrangement of the member on the other insulating substrate 1 surface may be required. . Such adjustment is difficult because both sides of the insulating substrate 1 cannot be seen simultaneously. Moreover, when arranging a member on the surface of one insulating substrate 1, it is necessary to maintain the cleanliness of the surface of the other insulating substrate 1 and to take care not to damage a member already disposed on the surface of the other insulating substrate 1. As a result, there are significant limitations in manufacturing process design. In that respect, in the configuration in which the conductive ball 7 connected to the circuit element and its terminal is disposed on one surface of the insulating substrate 1, there are no or few such difficulties and limitations.
[0017]
The “protective film” is formed, for example, by forming a thick film of paste-like glass or resin by a method such as screen printing, and then curing through baking and heating processes. It is preferable to use an epoxy resin as such a resin from the viewpoints of availability, cost, heat resistance, chemical resistance, and the like.
[0018]
The “connection member” includes at least the solder layer 5. Another solder member, such as cream solder or conductive ball 7, is directly involved in the connection, and the solder layer 5 mainly serves to facilitate the connection between the electrode 2 and the other solder member in FIG. In this case, the solder layer 5 is a “connecting member” as long as it plays or plays a role.
[0019]
The “conductive ball” is, for example, a solid or so-called resin core solder ball, a ball having no solder made of a metal or an alloy such as copper, or a solid or so-called resin core metal surface covered with solder. Is the ball. Here, the solder used for the conductive ball 7 and the solder layer 5 is not only Pb—Sn alloy but also so-called Pb free solder, for example, Sn alone, Sn—Bi alloy, Sn—In—Ag alloy, Sn— Bi—Zn alloy, Sn—Zn alloy, Sn—Ag—Bi alloy, Sn—Bi—Ag—Cu alloy, Sn—Ag—Cu alloy, Sn—Ag—In alloy, Sn—Ag— Cu-Sb alloy, Sn-Ag alloy, Sn-Cu alloy, Sn-Sb alloy and the like are included.
[0020]
The “plating technology” includes both electrolytic plating technology and electroless plating technology. Among them, the so-called barrel plating technique that is advantageous in terms of cost and has a track record of use in electronic parts is preferable in the present invention.
[0021]
The “land” referred to in this specification means a region where the conductive ball 7 is placed and is formed by an opening of the protective film 6. Further, the “terminal” in this specification is a terminal of a circuit element, and includes an electrode 2 existence region where the conductive ball 7 is not placed. After the conductive ball 7 is placed and fixed on the electrode 2, the conductive ball 7 and the conductive ball 7 become “terminals”.
[0022]
In addition, the state where “a part of the solder layer is covered with the protective film 6” can be a state that can be grasped from FIGS. 1F, 1G, and 1H as a representative example. That is, at least the periphery of the land 8 is covered with the protective film 6. In this case, the portion of the solder layer 5 other than the solder layer 5 exposed due to the presence of the land 8 becomes the “part of the solder layer”.
[0023]
(Ancillary effects of the first manufacturing method)
There is an advantage that the solder layer 5 can be formed thick also by the barrel plating technique. If the second step is performed after the third step, the electrode 2 (land 8) exposed as the opening of the protective film 6 is formed as shown in FIGS. 1 (f ′) and (g ′). It becomes a very narrow area. Then, in order to form the plating layer with a predetermined thickness in the region by using the barrel plating technique, a dummy ball having a very small diameter is used, and the distance between the contacts of the adjacent dummy balls is reduced, so that the dummy ball is made higher on the land 8. Contact with probability is required.
[0024]
However, with the use of the dummy balls, electrodeposits gradually accumulate, and the diameter of the dummy balls gradually increases. For this reason, the use of dummy balls having a small diameter at the beginning and ensuring contact with the lands with high probability has realized high-efficiency plating, but the plating efficiency gradually decreases. Then, it becomes very difficult to obtain a sufficiently thick plating layer.
[0025]
In that respect, when the second step is performed before the third step as in the first manufacturing method of the present invention, the electrode 2 (land 8) exposed as the opening of the protective film 6 is shown in FIG. As shown in 1 (f) and (g), the area is relatively wide. Then, the phenomenon in which the plating efficiency gradually decreases is suppressed, and the solder layer 5 can be formed thick.
[0026]
Further, there is an advantage that the plating condition burden on the barrel plating process (for example, using a specially small dummy ball and maintaining its small size) is not increased. Furthermore, it goes without saying that there is an advantage that the fixing strength between the land 8 and the conductive ball 7 is stably increased as the thickness of the solder layer 5 increases.
[0027]
(Second production method of the present invention)
In order to solve the above problems, a second method for manufacturing an electronic component according to the present invention includes a circuit element on one surface of an insulating substrate 1 constituting the electronic component, a protective film 6 for protecting the circuit element, and the protection. In the method of manufacturing an electronic component having a thick film-formed circuit element terminal located at the opening of the film 6 and a conductive ball 7 connected to the circuit element terminal and having at least a surface of solder, the insulating substrate 1 An eleventh step of forming the circuit element on one surface of the substrate so that the circuit element terminal formed with the thick film is exposed, and an opening of the protective film 6 protecting the circuit element partially covers the circuit element terminal. And the circuit element terminal and the conductive ball 7 are present in a region where the high-viscosity flux is in the opening region and narrower than that. 13th temporarily fixed And a fourteenth step of heating so that the circuit element terminal and the surface of the conductive ball 7 are fixed to each other, the eleventh step, the twelfth step, the thirteenth step, and the fourteenth step. Are performed in this order.
[0028]
(Specific description of the second production method)
An example of the second manufacturing method will be described with reference to FIG. A pair of thick electrodes 2 are formed on one surface of the insulating substrate 1 (FIGS. 2A and 2B). And the resistor 3 is formed so that both the electrodes 2 used as the pair may be contact | connected (FIG.2 (c)). Further, if necessary, a glass 4 film for protecting the resistor 3 is formed (FIG. 2D), and a resistance element which is an example of the circuit element is formed. The above is the eleventh step.
[0029]
Next, the protective film 6 is formed so that the opening of the protective film 6 that protects the resistance element exposes the land 8 that is a part of the circuit element terminal (FIG. 2E). The above is the twelfth step.
[0030]
Next, a high-viscosity flux 9 is used to temporarily fix the surface of the land 8 and a conductive ball having at least a surface of solder. At this time, the flux 9 is in the opening (land 8) region and in a narrower region (FIG. 2 (f)). The above is the thirteenth step.
[0031]
Thereafter, the conductive ball 7 is disposed in the flux 9 existing region (FIG. 2G). Then, by heating so that the land 8 and the surface of the conductive ball 7 are fixed, the solder on the surface of the conductive ball 7 is melted and solidified while the flux 9 is burned off, and the land 8 and the conductive ball 7 are fixed. (FIG. 2 (h)). The above is the 14th step. Through the above process, the electronic component (resistor) according to the present invention can be obtained.
[0032]
(Reason why the second manufacturing method solves the problem)
The high-viscosity flux 9 can temporarily fix the conductive ball 7 relatively firmly because of the high viscosity. Further, since the high-viscosity flux 9 exists in the land 8 region and in a narrower region, it is difficult to form a region having good wettability with the solder outside the land 9 region. Furthermore, the solder on the surface of the conductive ball 7 itself is melted and solidified, and there is no excessive solder such as cream solder. Therefore, the conductive ball 7 is difficult to move out of the land 8 in the process of melting and solidifying. Therefore, the product reliability of the electronic component is increased in that the position of the conductive ball 7 is not easily displaced from the position where the conductive ball 7 is set when the electronic component is designed, and the problem of the present invention can be solved.
[0033]
Here, it is preferable that the circuit element terminal surface is plated with a material having good wettability with solder at any stage after the eleventh process and before the thirteenth process. The reason is that the product reliability of the electronic component is enhanced in that the fixing strength between the land 8 and the conductive ball 7 is increased, and the problem of the present invention can be solved. The material having good wettability with the solder is, for example, one or more of solder, gold, and copper.
[0034]
(Definition of terms in the second production method, etc.)
The meanings of terms used in the first manufacturing method such as the above-mentioned “electronic component” are synonymous with terms used in the description of the second manufacturing method and a preferable manufacturing method based on the second manufacturing method. In addition to the above, the “high viscosity flux” means that the deformation due to its own weight does not substantially occur in the state of being placed on the land 8 and is approximately 20 Pa · S (25 ° C.). It is also necessary to have adhesiveness that can hold (temporarily fix) the conductive balls 7 to some extent.
[0035]
Further, the above “conductive ball having at least a surface of solder” refers to a “conductive ball” in the description of the first manufacturing method excluding those having no solder on the surface.
[0036]
(Ancillary effects of the second manufacturing method)
Thick film conductors containing metal glaze, resin, etc. and formed by screen printing or the like generally have poor solder wettability on the surface. However, due to the high viscosity of the high viscosity flux, the time until it is burned out by heating is longer than that of a normal low viscosity flux. Therefore, the contact surface between the land 8 and the conductive ball 7 can exist on the joint surface until the land 8 and the contact surface are sufficiently bonded and fixed.
[0037]
If an attempt is made to construct an electronic component simply, rationally and inexpensively using an insulating substrate 1 in which circuit elements and all lands 8 are formed on one surface of the insulating substrate 1 and no via hole is present, screen printing In some cases, thick film formation by the method is most preferable. In such a case, if the above barrel plating process is performed only to improve the solder wettability between the thick film conductor and the conductive ball 7, the advantage in such a case may be diminished. In this respect, the second manufacturing method is significant in that an electronic component can be formed without necessarily requiring such a plating step due to the action of the high viscosity flux.
[0038]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment of the first production method)
With reference to FIG. 1 and FIG. 3, a method of manufacturing an electronic component having a network resistance will be described. An insulating substrate 1 made of alumina ceramic is prepared (FIG. 1A). Such an insulating substrate 1 is a large-sized insulating substrate 1 in which a large number of insulating substrates 1 of individual electronic component sizes are arranged vertically and horizontally.
[0039]
A silver-palladium-based metal glaze paste is screen-printed on one surface of the insulating substrate 1 and then fired to obtain the electrode 2 and the common electrode 10 at the same time (FIGS. 1B and 3A). )). Since the insulating substrate 1 is large in size, there is an advantage that the electrode 2 and the common electrode 10 required for a large number of electronic components can be formed in one screen printing process. Such an advantage is an advantage of all the screen printing processes described below.
[0040]
Next, a ruthenium oxide resistor paste is screen-printed so as to be in contact with both the electrode 2 and the common electrode 10, and then fired to obtain the resistor 3 (FIG. 1 (c), FIG. 3 (b)). Further, a glass paste is screen-printed so as to cover the resistor 3, and then baked to obtain a glass 4 film (FIGS. 1D and 3C).
[0041]
Next, in order to set the resistance value of the resistance element composed of the electrode 2, the common electrode 10 and the resistor 3 to a desired value, a process of adjusting the resistance value by forming a trimming groove 11 in the resistor 3 by laser irradiation is performed. (FIG. 3 (d)). At this time, the glass 4 film acts to suppress damage of the entire resistor 3 as much as possible. The resistance element forming process so far is the first process described above.
[0042]
Thereafter, an epoxy resin paste or the like is disposed by screen printing (not shown) and cured so as to avoid at least the exposure of the trimming grooves 11. The temperature required for such curing is preferably low. This is to prevent the adjusted resistance value from shifting due to exposure to a high temperature. Therefore, it is more preferable to use a resin curing step that does not depend on heating, using a photo-curing resin such as an unsaturated polyester resin, on the condition that it has chemical resistance in the subsequent steps.
[0043]
Next, the insulating substrate 1 is divided (not shown) so as to obtain the insulating substrate 1 of each electronic component size from the large insulating substrate 1. The dividing means is based on so-called dicing, in which the diamond blade is rotated at a high speed to cut the insulating substrate 1. Instead of such dicing, a means for dividing the large insulating substrate 1 by using a large insulating substrate 1 in which a dividing groove is formed in advance along the outer shape of the electronic component and applying stress to open the groove. May be adopted. The advantage of the former (dicing) is that the dimensional accuracy of the electronic parts after division is generally high. The latter advantage is advantageous in terms of reducing manufacturing costs.
[0044]
The thus obtained insulating substrate 1 having the size of each electronic component is subjected to a solder plating process using a barrel plating method to obtain a solder layer 5 (FIGS. 1E and 3E). At this time, since the trimming groove 11 is not exposed, there is no inconvenience that the solder layer 5 is formed in the trimming groove 11. This step was performed until the thickness of the solder layer 5 became 3 to 12 μm. The step of obtaining the solder layer 5 is the second step described above.
[0045]
Thereafter, the individual electronic components are arranged side by side with the front and back sides aligned, and after the arrangement state is fixed, a protective film 6 having an opening is formed by screen printing of an epoxy resin paste and a subsequent heat curing step (FIG. 1). (F), FIG. 3 (f)). As a result, the opening portion partially exposes the solder layer 5 and becomes a land 8. Moreover, a part of the solder layer 5 is covered with the protective film 6 by this process. This step is the third step described above.
[0046]
Thereafter, cream solder (not shown) (lead: tin = 60: 40 wt%) is screen-printed on the lands 8 of the individual electronic components, and the conductive balls 7 are mounted using a commercially available ball mounting device (FIG. 1 (g)). The land 8 and the conductive ball 7 are fixed by melting and solidifying the cream solder and the surface layer of the conductive ball 7 (FIG. 1 (h)). The conductive ball 7 has a surface layer of lead: tin = 95: 5 wt% and a core made of copper. The melting and solidifying process is performed by a known reflow process. The first manufacturing method of the present invention is completed through the above steps.
[0047]
(Embodiment of second production method)
With reference to FIGS. 2 and 4, a method for manufacturing an electronic component having a network resistance will be described. The process until the trimming groove 11 is formed in the embodiment of the first manufacturing method is the same as that of the second manufacturing method. Therefore, the eleventh step is performed in the same manner as the first step in the first manufacturing method.
[0048]
After the trimming groove 11 is formed, the protective film 6 is formed in the same manner as in the first manufacturing method without performing other steps (FIGS. 2E and 4E). This step is the twelfth step described above.
[0049]
Thereafter, a high-viscosity flux 9 is disposed on the land 8 obtained by forming the protective film 6 (FIGS. 2 (f) and 4 (f)). As the flux 9, Senju Metal Industry Co., Ltd. (trade name: Deltalux 529D-1) was used. The arrangement method was a pin transfer method. At the time of the arrangement, attention was paid so that the flux 9 exists in the land 8 region and in a narrower region.
[0050]
Instead of the pin transfer method, a screen printing method, a ball transfer method using a conductive ball 7 instead of the pin, a dispenser method, or the like can be employed. Moreover, it cannot be overemphasized that it can replace with the said flux 9 (brand name: Deltalux 529D-1), and can have a viscosity and adhesiveness comparable as the said flux 9. FIG.
[0051]
Next, the conductive ball 7 was mounted under the same conditions as in the first manufacturing method except that the conductive ball 7 was mounted at the position where the flux 9 was present without using cream solder (FIG. 2G). ). This mounting process is the thirteenth process described above.
[0052]
Thereafter, the land 8 and the surface layer of the conductive ball 7 are fixed. Such an adhering step is based on a known reflow step similar to the embodiment of the first manufacturing method. This step is the fourteenth step described above. Through the above steps, the second production method of the present invention is completed.
[0053]
【The invention's effect】
According to the present invention, the product reliability of the electronic component can be improved. In particular, in the first manufacturing method, the connection strength of the connection portion between the conductive ball 7 and the land 8 can be increased. In the second manufacturing method, the arrangement of the conductive balls 7 determined at the time of designing the electronic component is provided. The product reliability of the electronic component could be improved in the sense that it is difficult to cause the displacement of the conductive ball 7 from the position.
[Brief description of the drawings]
FIGS. 1A to 1H are views showing a first manufacturing method of the present invention as a cross-sectional view of an electronic component for each step. (F ') and (h') are the figures which showed the case where it replaced with the stage of (f) and (h) concerning this invention, and manufactured the electronic component by an example of the manufacturing methods other than this invention.
FIGS. 2A to 2H are views showing a second manufacturing method of the present invention as a cross-sectional view of an electronic component for each step. FIGS.
FIG. 3 is a diagram showing a plan view of a circuit element and a conductive ball existing surface of an electronic component for each step in the first manufacturing method of the present invention.
FIG. 4 is a diagram showing a plan view of a circuit element and a conductive ball existing surface of an electronic component for each step in the second manufacturing method of the present invention.
[Explanation of symbols]
1. 1. Insulating substrate Electrode 3. Resistor 4. Glass 5. 5. Solder layer 6. Protective film Conductive ball 8. Land 9. Flux 10. Common electrode 11. Trimming groove 12. Bonding layer of solder layer 5 and conductive ball 7

Claims (5)

A circuit element on one surface of an insulating substrate constituting the electronic component, a protective film protecting the circuit element, a terminal connection land located in the protective film opening and constituting the circuit element, and the land In an electronic component having a conductive ball connected by a connecting member,
A part of the solder layer as the connection member formed on the land surface is covered with the protective film. A circuit element on one surface of an insulating substrate constituting the electronic component, a protective film for protecting the circuit element, a land located at the opening of the protective film, and a conductive ball connected to the land by a connecting member In the manufacturing method of electronic parts having
A first step of forming the circuit element on one surface of the insulating substrate such that the circuit element terminal is exposed;
A second step of forming a solder layer as the connection member on the circuit element terminal by plating technique;
A third step of forming a protective film so that the opening of the protective film protecting the circuit element partially exposes the solder layer;
The manufacturing method of the electronic component characterized by implementing the said 1st process, 2nd process, and 3rd process in this order. A circuit element on one surface of an insulating substrate constituting the electronic component, a protective film for protecting the circuit element, a circuit element terminal formed in a thick film located in the protective film opening, and the circuit element terminal In a method of manufacturing an electronic component having a conductive ball that is connected and at least a surface is solder,
An eleventh step of forming the circuit element on one surface of the insulating substrate so that the thick circuit-formed circuit element terminal is exposed;
A twelfth step of forming a protective film such that the opening of the protective film protecting the circuit element partially exposes the circuit element terminal;
A thirteenth step of temporarily fixing the circuit element terminal and the conductive ball in a state where the high-viscosity flux is present in the opening region and in a narrower region;
A fourteenth step of heating so that the circuit element terminal and the surface of the conductive ball adhere to each other;
A method of manufacturing an electronic component, wherein the eleventh step, the twelfth step, the thirteenth step, and the fourteenth step are performed in this order. 4. The electronic component according to claim 3, wherein the circuit element terminal surface is plated with a material having good wettability with solder at any stage after the eleventh step and before the thirteenth step. Manufacturing method. 5. The method of manufacturing an electronic component according to claim 4, wherein the material having good wettability with solder is at least one of solder, gold, and copper.

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