JP2022014159A - Method for manufacturing element module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an element module in which damage to an element is suppressed in a method for manufacturing an element module in which an element which is easily damaged is also mixed.
A method for manufacturing an element module includes a step of preparing a module main body 30 including a circuit board 2 having a main surface 10 and a first element 4 and a second element 3 arranged on the main surface 10. Mainly, a step of forming the first mold resin 6 covering the first element 4 on the module main body 30 using one mold, and covering the first mold resin 6 and the second element 3 using the second mold. The first element 4 includes a fragile portion damaged by an external force lower than that of the second element 3, and the molding pressure when forming the first mold resin 6 is the step of forming the second mold resin 7 on the surface 10. It is lower than the molding pressure for forming the second mold resin 7.
[Selection diagram] Fig. 1

Description

The present disclosure is a method for manufacturing an element module.

Generally, the element module includes a circuit board, a plurality of elements arranged on the circuit board, and a mold resin formed so as to cover the plurality of elements.

As a method for manufacturing an element module, for example, as described in Japanese Patent Application Laid-Open No. 2004-111435, a step of arranging a plurality of elements on a circuit board to form a module main body and a mold resin on the element module are used. Including the step of forming.

The step of forming the mold resin includes a step of arranging the element module in the mold and a step of injecting the resin into the mold.

Japanese Unexamined Patent Publication No. 2004-111435

Various elements are mounted on the element module, and some elements are easily damaged by external pressure.

On the other hand, when forming the mold resin, it is necessary to supply the resin into the mold with an injection pressure equal to or higher than a predetermined value in order to distribute the resin in the mold in which the module main body is arranged.

Therefore, when an element that is easily damaged is mounted on the circuit board, the element may be damaged in the process of forming the mold resin.

The present disclosure has been made in view of the above-mentioned problems, and an object thereof is a method for manufacturing an element module in which damage to an element is suppressed in a method for manufacturing an element module in which an element that is easily damaged is also mounted. Is to provide.

The method for manufacturing an element module according to the present disclosure uses a step of preparing a module main body including a circuit board having a main surface and a first element and a second element arranged on the main surface, and a first mold. A step of forming a first mold resin covering the first element on the module body, and a step of forming a second mold resin on the main surface so as to cover the first mold resin and the second element using a second mold. The first element contains a fragile portion that is damaged by an external force lower than that of the second element, and the molding pressure when forming the first mold resin is lower than the molding pressure for forming the second mold resin.

According to the above-mentioned method for manufacturing an element module, when the second mold resin is formed, the first mold resin that covers the first element including the fragile portion is formed, so that the first element is suppressed from being damaged. can do.

According to the method for manufacturing an element module according to the present disclosure, damage to an element can be suppressed in the method for manufacturing an element module in which an element that is easily damaged is also mounted.

It is sectional drawing which shows the element module 1. FIG. It is a side sectional view showing an aluminum electrolytic capacitor 4. It is a flow diagram which shows the manufacturing process which manufactures the element module 1. It is sectional drawing which shows typically the preparation process S1. It is sectional drawing which shows the 1st resin formation process S2. It is sectional drawing which shows the 2nd resin formation process S3.

The element module according to this embodiment will be described with reference to FIGS. 1 to 6. Of the configurations shown in FIGS. 1 to 6, the same or substantially the same configuration is designated by the same reference numerals and duplicated description will be omitted.

FIG. 1 is a cross-sectional view showing the element module 1. The element module 1 includes a module main body 30 and mold resins 6 and 7.

The module main body 30 includes a circuit board 2, a plurality of semiconductor elements 3, an aluminum electrolytic capacitor 4, and a connector 5.

The circuit board 2 includes, for example, a ceramic substrate and circuit wiring formed on the ceramic substrate. The circuit board 2 includes a main surface 10 and a main surface 11, and a plurality of semiconductor elements 3, an aluminum electrolytic capacitor 4, and a connector 5 are mounted on the main surface 10.

The semiconductor element 3 is, for example, a semiconductor bare chip or the like. The semiconductor element 3 is connected to the circuit wiring formed on the circuit board 2 by wire bonding or the like (not shown).

The connector 5 includes a connector main body 15 and terminals 16. A connector provided outside the element module 1 is connected to the connector 5. The connector body 15 is made of resin. The terminal 16 is arranged in the connector main body 15, and the connection wire 17 connects the terminal 16 and the circuit wiring of the circuit board 2.

The mold resin 6 is formed so as to cover the aluminum electrolytic capacitor 4. Specifically, while it is formed so as to cover the mold resin 6, it is not formed on other elements located around the mold resin 6.

The mold resin 7 is formed on the main surface 10 of the circuit board 2. The mold resin 7 is formed so as to cover the plurality of semiconductor elements 3, the connector 5, and the mold resin 6. The mold resins 6 and 7 are formed of, for example, an epoxy resin molding material.

FIG. 2 is a side sectional view showing an aluminum electrolytic capacitor 4. The aluminum electrolytic capacitor 4 includes a metal case 20, a sealing member 21, lead wires 22, 23, an electrode body 24, a pedestal 26, and terminals 27, 28.

The metal case 20 is made of aluminum or the like. The metal case 20 is formed with an opening 25 that opens downward.

The electrode body 24 is housed in the metal case 20. The electrode body 24 includes an electrolytic paper and an aluminum electrode foil. The electrolytic paper and the aluminum electrode foil are wound in a laminated state. The electrode body 24 is impregnated with the electrolytic solution.

The sealing member 21 is made of resin. The sealing member 21 is formed so as to close the opening 25. The pedestal 26 is arranged below the sealing member 21, and the pedestal 26 is arranged on the main surface 10. The pedestal 26 is made of resin or the like.

Here, the sealing member 21 and the pedestal 26 are formed of a resin material, and for example, the withstand pressure of the sealing member 21 and the pedestal 26 is lower than the withstand pressure of the semiconductor element 3. For example, the load at which the sealing member 21 and the pedestal 26 are cracked is smaller than the load at which the semiconductor element 3 is deteriorated in performance. That is, in the present embodiment, "at least one of the sealing member 21 and the pedestal 26" corresponds to the "fragile portion".

The terminals 27 and 28 are arranged in the sealing member 21, and the terminals 27 and 28 are electrically connected to the electrode body 24.

The lead wires 22 and 23 are electrically connected to the terminals 27 and 28, and are formed so as to pass through the pedestal 26 and be drawn out from the pedestal 26. The lead wires 22 and 23 are connected to the circuit wiring formed on the main surface 10.

FIG. 3 is a flow chart showing a manufacturing process for manufacturing the element module 1. The manufacturing process of the element module 1 includes a preparation step S1, a first resin forming step S2, and a second resin forming step S3.

FIG. 4 is a cross-sectional view schematically showing the preparation step S1. The preparation step S1 is a step of preparing the module main body 30. The step of preparing the module main body 30 includes a step of forming the circuit board 2 and a step of mounting a plurality of semiconductor elements 3, an aluminum electrolytic capacitor 4, and a connector 5 on the main surface 10 of the circuit board 2.

The step of forming the circuit board 2 includes a step of preparing a ceramic substrate and a step of forming circuit wiring on the main surface of the ceramic substrate.

FIG. 5 is a cross-sectional view showing the first resin forming step S2. The first resin forming step S2 is a step of forming the mold resin 6 on the module main body 30 by using the first mold 31.

The preparation step S1 includes an arrangement step of arranging the module main body 30 on the upper surface of the mounting table 32, an arrangement step of arranging the first mold 31 on the main surface 10 of the module main body 30, and a first metal using the injection device 33. It includes an injection step of injecting resin into the mold 31 and a heat curing step.

The first mold 31 is formed in a hollow shape. A cavity 34 and an insertion port 35 are formed in the first mold 31. The cavity 34 is open downward, and the opening 36 is formed in the first mold 31. The insertion slot 35 is connected to the upper end of the cavity 34.

The injection device 33 includes a cylinder 37 and a piston 38, and the cylinder 37 is filled with resin 39.

In the arrangement step of arranging the first mold 31, the first mold 31 is arranged so as to cover the aluminum electrolytic capacitor 4. At this time, a gap is formed between the inner surface of the cavity 34 and the aluminum electrolytic capacitor 4, and this gap is used as the space R1. The semiconductor element 3 and the like are not covered by the first mold 31.

In the injection step, the tip of the cylinder 37 is inserted into the insertion port 35. Then, the piston 38 pressurizes the resin 39, and the resin 39 is injected into the cavity 34. The resin 39 is a thermosetting resin such as an epoxy resin. The temperature of the resin 39 in the cylinder 37 is, for example, 60 ° C to 80 ° C, and the resin 39 is in a fluid state. The pressure at which the resin 39 is injected into the cavity 34 is the molding pressure P1. The molding pressure P1 (kg / cm ² ) is, for example, about 2 to 10 (kg / cm ² ).

In the thermosetting step, the resin 39 is thermoset while the molding pressure P1 is applied to the resin 39. The mold resin 6 is formed by thermally curing the resin 39. In the thermosetting step, the temperature of the resin 39 in the space R1 is about 130 ° C. to 170 ° C.

After that, by removing the first mold 31, the module main body 30 on which the mold resin 6 is formed can be manufactured.

FIG. 6 is a cross-sectional view showing the second resin forming step S3. The second resin forming step S3 is a step of forming the mold resin 7 by using the second mold 40.

The second mold 40 includes a lower mold 41 and an upper mold 42, and a cavity 43 is formed in the second mold 40. A recess 44 is formed in the lower mold 41. The upper mold 42 is formed with a recess 45, a gate 46, and a filling chamber 47. When the lower mold 41 and the upper mold 42 are combined, the cavity 43 is formed by the recess 44 and the recess 45.

The gate 46 communicates with the recess 45 and the filling chamber 47. The filling chamber 47 is filled with the resin 48.

In the second resin forming step S3, the module main body 30 in which the mold resin 6 is formed is arranged in the recess 44, and the upper mold 42 is assembled to the lower mold 41 to form the module main body 30 in the cavity 43. It includes a second placement step of arranging the resin 48, an injection step of injecting the resin 48, and a heat curing step.

In the second arrangement step, when the module main body 30 on which the mold resin 6 is formed is arranged in the cavity 43, a gap is formed between the inner surface of the cavity 43 and the module main body 30. The gap formed between the inner surface of the cavity 43 and the module main body 30 is defined as the space R2.

In the injection step, the piston 49 pressurizes the resin 48 in the filling chamber 47. As a result, the resin 48 is injected into the cavity 43 through the gate 46. The pressure at which the resin 48 is injected into the cavity 43 is defined as the molding pressure P2. In the injection step, the temperature of the resin 48 in the filling chamber 47 is, for example, 60 ° C to 80 ° C, and the resin 48 is in a fluid state.

In the thermosetting step, the resin 48 is thermosetting in a state where the molding pressure P2 is applied to the resin 48. At this time, the temperature of the resin 48 in the space R2 is about 130 ° C to 170 ° C. As a result, the resin 48 is thermally cured to form the mold resin 7. The resin 48 is, for example, an epoxy resin.

Comparing the space R1 shown in FIG. 5 and the space R2 shown in FIG. 6, the space R2 is wider. Further, the space R2 is wider in the horizontal direction than the space R1, and the space R2 has a more complicated shape than the space R1.

Therefore, it is difficult to fill the space R2 with the resin 48, and if the molding pressure P2 is lower than the molding pressure P1 in the injection step, the resin 48 may flow back from the gate 46 or the resin 48 may be placed in the space R2. It doesn't spread.

As a result, even after the resin 48 is filled, voids are formed in the space R2, and the filling density of the resin 48 varies. If the resin 48 is thermally cured in such a state, the mold resin 7 and the element module 1 itself may shrink, or molding defects of the mold resin 7 may occur. As a result, there arises a problem that the dimensional accuracy of the mold resin 7 and the element module 1 deteriorates. Therefore, the forming pressure P2 is set higher than the forming pressure P1, and the forming pressure P1 is set lower than the forming pressure P2.

For example, the molding pressure P1 (kg / cm ² ) is about 2 to 10 (kg / cm ² ), and the molding pressure P2 is about 20 to 50 (kg / cm ² ).

Then, the element module 1 can be manufactured by removing the element module 1 on which the mold resin 7 is formed from the second mold 40.

In the above-mentioned manufacturing method of the element module 1, when the mold resin 7 is formed, the mold resin 6 that covers the aluminum electrolytic capacitor 4 is already formed. Therefore, when forming the mold resin 7, it is possible to prevent the molding pressure P2 from being directly applied to the sealing member 21 and the pedestal 26 of the aluminum electrolytic capacitor 4. As a result, it is possible to prevent the sealing member 21 and the pedestal 26, which are fragile portions, from being cracked.

In the above-mentioned manufacturing method of the element module 1, when the mold resin 6 is formed, a low-pressure molding pressure P1 is applied to the sealing member 21 and the pedestal 26. Therefore, damage to the sealing member 21 and the pedestal 26 is suppressed in the process of forming the mold resin 6.

Further, since the mold resin 7 that covers the mold resin 6 is formed after the mold resin 6 is formed, the dimensional accuracy required for the mold resin 6 does not have to be high, and the waterproof performance required for the mold resin 6 is not high. Does not have to be expensive. Therefore, the mold resin 6 can be easily formed.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is indicated by the scope of claims and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 element module, 2 circuit board, 3 semiconductor element, 4 aluminum electrolytic capacitor, 5 connector, 6,7 mold resin, 10,11 main surface, 15 connector body, 16,27,28 terminals, 17 connection wire, 20 metal case , 21 Sealing member, 22,23 lead wire, 24 electrode body, 25,36 opening, 26 pedestal, 30 module body, 31 1st mold, 32 pedestal, 33 injection device, 34,43 cavity, 35 insertion port , 37 Cylinder, 38,49 Piston, 39,48 Resin, 40 Second Mold, 41 Lower Mold, 42 Upper Mold, 44,45 Recess, 46 Gate, 47 Filling Chamber, 2004 JP, P1, P2 Molding Pressure, R1, R2 space, S1 preparation step, S2 first resin forming step, S3 second resin forming step.

Claims (1)

A step of preparing a module main body including a circuit board having a main surface and a first element and a second element arranged on the main surface.
A step of forming a first mold resin covering the first element on the module body using the first mold, and a step of forming the first mold resin.
A step of forming the second mold resin on the main surface so as to cover the first mold resin and the second element using the second mold, and a step of forming the second mold resin.
Equipped with
The first element contains a fragile portion that is damaged by a lower external force than the second element.
A method for manufacturing an element module, wherein the molding pressure when forming the first mold resin is lower than the molding pressure for forming the second mold resin.

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