JP3333084B2 - Method of manufacturing bare chip molded part and bare chip molded part manufactured by the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a bare chip molded part and a bare chip molded part produced by the method, and more particularly, to a method for producing a bare chip molded part capable of preventing wire breakage of a bare chip in a production process. And a bare chip molded part manufactured by the method.

[0002]

2. Description of the Related Art A bare chip molded component incorporated in a cellular phone or the like generally employs a structure in which a bare chip wire-bonded on a substrate for mounting electronic components is sealed with a resin. As a structure and a manufacturing method of such a bare chip molded part, Japanese Utility Model Laid-Open No. 63-1556 discloses
One disclosed in Japanese Patent Publication No. 45 is known. FIG.
FIG. 2 is an explanatory view of such a bare chip molded part.

In manufacturing the bare chip molded part 600, first, bare chips 2a, 2b,
2c is provided, and wires 21 extending from the bare chips 2a to 2c are bonded to a circuit (not shown) on the substrate 1.

Next, around the bare chips 2a to 2c,
The dam frame 610 is formed. Then, each bare chip 2a ~
Partitions 611a and 611b for partitioning 2c are formed. The partitions 611a and 611b partition the dam frame 610 by the number of bare chips.

Next, a sealing resin 612 is dropped for each of the above sections. The bare chips 2a to 2c are buried in the sealing resin 612. The sealing resin 612 is, for example, a silicone resin. Subsequently, the sealing member 612 is cured by heating.
Forming a sealing resin layer 612a in the dam frame 610;
The bare chips 2a to 2c are sealed.

[0006] In this case, compared with the case where the sealing resin 612 is dropped into the dam frame 610 without the partition 611,
The sealing resin 612 can be prevented from protruding from the dam frame 610, and the bare chips 2a to 2c can be satisfactorily removed.
It can be sealed in 10.

[0007]

However, when manufacturing the above-described conventional bare chip molded component 600, special consideration is given to the case where the sealing resin 612 thermally expands and the case where the bare chips 2 having different sizes are provided. Absent.

Generally, the sealing resin 612 thermally expands due to heating at the time of sealing a bare chip or heating at the time of mounting another electronic component. For this reason, there is a problem that the wire 21 of the bare chip 2 may be disconnected by being pulled.

Further, since the thermal expansion coefficient differs depending on the portion (for example, the central portion and the outer peripheral portion) of the sealing resin layer 612a, internal stress is generated in the sealing resin layer 612a, and the wire 21 of the bare chip 2 is There is a problem that the wire may be disconnected by being pulled.

Also, bare chips 2a to 2c having different sizes are provided.
Is provided, a difference occurs in the coefficient of thermal expansion in each part of the sealing resin 612 due to a difference in heat radiation to the bare chips 2a to 2c. For this reason, there is a problem that an internal stress is generated in the sealing resin layer 612a, and the wire 21 may be pulled and disconnected.

Further, even though a large-sized bare chip (for example, bare chip 2c) is provided, the sealing resin 612 of a normal size is dropped.
The extra 2 overflows the outside of the dam frame 610 and the adjacent section and protrudes. For this reason, there is a problem that an appropriate sealing resin layer 612 cannot be secured, and the mounting area of other electronic components on the substrate 1 is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and has been made in consideration of the above circumstances, and a method of manufacturing a bare chip molded component capable of preventing disconnection of a wire and preventing protrusion of a sealing resin, and a bare chip manufactured by the method. The purpose is to obtain a molded part.

[0013]

In order to achieve the above-mentioned object, a method of manufacturing a bare chip molded part according to the present invention comprises a first resin having a low expansion coefficient and a high viscosity, a resin around a plurality of bare chips. Simultaneously forming a wall and a partition wall for partitioning the inside of the resin wall in units of the bare chips; and filling the inside of the resin wall with a second resin having substantially the same expansion coefficient and viscosity as the first resin. A step of sealing the bare chip by substantially simultaneously heating and curing the first resin and the second resin. When a plurality of bare chips having different sizes are provided, the resin wall and the partition wall are provided. Is formed at a height commensurate with the size of each bare chip.

This manufacturing method gives excellent characteristics to the manufactured bare chip mode component. Generally, a bare chip mode component after a bare chip is sealed undergoes various processes for mounting other electronic components. However, when heated in a reflow furnace for soldering or the like, for example, the resin sealing the bare chip expands, and a wire extending from the bare chip generates a tensile stress and breaks. However, as described above, since the resin wall, the partition wall, and the resin to be filled are made of a resin having a low expansion coefficient, they hardly expand even when heated. Therefore, disconnection of the wire due to expansion can be prevented.

Further, the bare chip is sealed by first forming a resin wall around the bare chip and filling the inside thereof with a resin. However, the bare chip is sealed with the resin wall (first resin). 2) and heat-cured separately, for example,
When the wire is located at the interface between the two resins, a tensile stress is applied to the wire, and there is a possibility that the wire is disconnected.
In view of this, the first resin and the second resin are made of resins having the same degree of expansion, and simultaneously heated and cured to suppress the generation of internal stress. As a result, no tensile stress is applied to the wire, and disconnection can be prevented.

In the bare chip mold, it is necessary to make the sealing resin (second resin) flow uniformly in the resin wall (first resin). Does not allow the dropped resin to flow uniformly over the whole. For this reason, the inside of the resin wall is partitioned by a partition, and the resin is dropped on each partition.

However, when a low-viscosity resin is used, the resin easily overflows from the resin walls and partitions due to low surface tension. Therefore, a high-viscosity resin having a large surface tension is used to prevent the resin from overflowing. In addition, even with a high-viscosity resin, sufficient flow can be ensured for each section in the resin wall. In particular, even when the resin is dripped too much onto a large-sized bare chip, the resin is unlikely to overflow. As a result, the resin does not overflow onto the substrate, and the mounting density of electronic components on the substrate is improved in relation to other electronic components.

Since the amount of resin for sealing the bare chip should be an appropriate amount, the amount of resin is adjusted according to the height of the partition. For example, for a large bare chip, the partition is raised to increase the resin filling amount, and for a small bare chip, the partition is lowered to reduce the resin filling amount. As a result, the yield of the resin is improved.

A method of manufacturing a bare chip molded part according to the next invention is a step of forming a resin wall or a partition wall so that a part of a wire extending from a bare chip is filled with the first resin; In filling the inside of the resin wall so that the other part of the wire is filled,
Sealing the bare chip by heating and curing the first resin and the second resin substantially simultaneously.

That is, when the base of the wire of the bare chip is covered with a resin wall (first resin), if the expansion rates of the first resin and the second resin are different, the wire is pulled at the interface between the two resins and the wire is disconnected. I do. Thus, the first resin and the second resin are made of resins having substantially the same expansion coefficient to prevent disconnection. Also, peeling of the bonding portion can be prevented.

In the method of manufacturing a bare chip molded part according to the next invention, when a plurality of the bare chips are provided, a resin wall or a resin wall is formed by the first resin so that a part of a wire extending from a predetermined bare chip is simultaneously filled. It forms a partition wall.

That is, a plurality of wires may be bonded on the same circuit of the substrate in order to increase the mounting density of electronic components. In such a case, if the plurality of wires are covered with the first resin, In addition, it is possible to increase the mounting density while preventing disconnection.

A bare chip molded part according to the next invention is a first resin forming a resin wall formed around a bare chip, a partition wall for partitioning the inside of the resin wall for each bare chip, The second resin that is filled and cured to seal the bare chip has at least approximately the same expansion coefficient, and is made of a high-viscosity resin, and when a plurality of bare chips having different sizes are provided, the resin wall and The partition wall has a height suitable for each bare chip.

Here, the first resin and the second resin are
Because at least the expansion rate is made of the same resin,
That is, since the resin wall and the partition wall around the bare chip and the resin for sealing the bare chip are configured by the resin having substantially the same expansion coefficient, the wire breakage inside the resin is reduced, and a high quality bare chip molded part is obtained. .

Further, since the resin is filled at the height of the partition corresponding to each bare chip, the yield of the resin is improved.

A bare chip molded part according to the next invention is configured such that a wire extending from the bare chip passes through an interface between the first resin and the second resin.

That is, if the base of the wire of the bare chip is covered with a resin wall, the wire passes through the interface between the first resin and the second resin, and both resins have at least substantially the same low expansion coefficient. Therefore, no tensile stress is applied to the wire. As a result, disconnection of the wire is prevented.

The bare chip molded part according to the next invention has a structure in which, when a plurality of the bare chips are provided, a part of the wire extending from a predetermined bare chip is embedded in the first resin.

That is, as described above, even when a plurality of wires are bonded on the same circuit of the substrate, if the plurality of wires are covered with the first resin, the disconnection can be prevented and the mounting density can be increased. it can.

A method of manufacturing a bare chip molded part according to the next invention is characterized in that a resin wall having a high viscosity and a low expansion coefficient is formed around a plurality of bare chips having different sizes and on a wire ball around the bare chip. Forming a partition wall for partitioning the inside of the resin wall for each bare chip, and filling the inside of the resin wall with a second resin having substantially the same main components as the resin wall and the partition wall. And a step of sealing the bare chip by heating and curing the first resin and the second resin substantially simultaneously, wherein the resin wall and the partition wall have a height corresponding to the size of each bare chip. Things.

That is, a resin wall and a partition wall are formed of a first resin having a high viscosity and a low expansion coefficient, and the resin wall is filled with a second resin having the same component as the first resin. . Than this,
Wire breakage of the bare chip can be prevented. Further, since the resin can be prevented from overflowing, the electronic component mounting density of the substrate is improved.

Further, since the height of the resin wall and the partition wall is set in accordance with the size of each bare chip, the amount of resin dripped can be easily controlled, and the yield of resin can be improved.

The bare chip molded part according to the next invention is provided around a plurality of bare chips having different sizes, and
A resin wall formed on the wire ball around the bare chip and a partition wall for partitioning the inside of the resin wall are formed of a first resin having a high viscosity and a low expansion coefficient, and the inside of the resin wall is
The resin wall and the partition wall have a structure filled with a second resin composed of the same main component as the resin wall and the partition wall, and the resin wall and the partition wall have a height corresponding to the size of each bare chip.

That is, since the structure is filled with the second resin composed of the same main component as the resin wall and the partition wall, there is little disconnection of the bare chip wires, and the quality is improved because the electronic component mounting density is high. .

Further, since the resin wall and the partition wall have a height corresponding to the size of each bare chip, the yield of resin is improved and a product can be manufactured at low cost.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method of manufacturing a bare chip molded part according to the present invention and a bare chip molded part manufactured by the method will be described in detail with reference to the drawings. The present invention is not limited by the embodiment.

(Embodiment 1) FIG. 1 is an explanatory view showing a bare chip molded part manufactured by a manufacturing method according to the present invention, and FIG.
FIG. 2 is a sectional view taken along line AA ′ shown in FIG.

In this bare chip molded component 100, reference numeral 1 denotes a substrate on which electronic components are mounted. Bare chips 2d and 2e are provided on the circuit forming surface of the substrate 1. Around the bare chips 2d and 2e, a dam frame 11 is provided.
The dam frame 11 is partitioned by a partition 12 for each bare chip. In addition, bare chip 2
d and 2e are sealed by the sealing resin layer 20a.

FIG. 3 is a flowchart showing the steps of manufacturing the bare chip molded part of the present invention. Step S
In 1, first, the bare chips 2 d and 2 e are arranged on the substrate 1, and the wires 21 extending from the bare chips 2 d and 2 e are bonded on the circuit of the substrate 1.

In step S2, bare chips 2d, 2e
Around the dam frame 11, and each bare chip 2d, 2
and a partition 12 for partitioning e. For example, by extruding the resin from the nozzle, first, partition 1
2 from one end, and then the surrounding dam frame 11
And finally to the other end of the partition 12, and the process is completed. This partition 12 allows the dam frame 11 to bear the bare chip 2
It is divided into sections (10a, 10b) for each of d and 2e. Further, the dam frame 11 and the partition 12 (the combined one is hereinafter referred to as a common cell 10) are formed on a wire ball 22, as shown in FIG.

The common cell 10 includes, for example, an epoxy resin mixture (product name: V974, manufactured by Ryoden Kasei) comprising an epoxy resin, an acid anhydride, a catalyst, an additive, and an inorganic filler.
Solvent-free, one-part acid anhydride-curing encapsulant (Hitachi Chemical:
It is a material having a high viscosity and a low coefficient of expansion such as CEC-0041, 0042).

The height of the common cell 10 is determined by the size of the bare chips 2d and 2e. For example, as shown in FIG. 2, a high common cell 10 is formed around a thick bare chip 2d, and a low common cell 10 is formed around a thin bare chip 2e. The height of the common cell 10 is controlled by the diameter and pressure of a nozzle for extruding resin.

In step S3, the sealing resin 20 is dropped for each of the sections 10a and 10b. The sealing resin 20 is, for example, an epoxy resin mixture (product name: V9, manufactured by Ryoden Kasei) comprising an epoxy resin, an acid anhydride, a catalyst, an additive, and an inorganic filler.
75) or a high-viscosity, low-expansion material such as a non-solvent type one-component acid anhydride-curing sealing material (trade name: CEC-1900, manufactured by Hitachi Chemical Co., Ltd.). The sealing resin 20 is filled in a state where the sealing resin 20 rises from the top of the common cell 10 due to surface tension (see FIG. 2). The bare chips 2d and 2e are made of a sealing resin 20.
Buried in

The amount of the sealing resin 20 dropped is adjusted according to the size of the bare chips 2 d and 2 e and the height of the common cell 10. For example, when the thickness is large and the surface area is small like the bare chip 2d and the surrounding common cell 10 is high, the amount of dripping is small. When the surrounding common cell 10 is thin and the surface area is small like the bare chip 2e. Adjust the dropping amount to a larger amount.

In step S4, the common cell 10 and the sealing resin 20 are simultaneously cured by heating. Since the common cell 10 and the sealing resin 20 are substantially the same material having a low expansion coefficient,
There is almost no difference in the coefficient of thermal expansion due to heating. Also,
Even when the expansion coefficient of the sealing resin 20 is large, the sealing resin 20
Is prevented by the common cell 10. Thus, the bare chip 2 is sealed by the cured sealing resin layer 20a.

The heating is performed as follows. First, the sealing resin 20 is heated at a temperature at which the viscosity of the sealing resin 20 decreases (80 to 110 ° C.) for 40 minutes.
(~ 150 ° C) for 30 minutes to cure. Then 1
Heat for 30 minutes while lowering the temperature to 30 to 140 ° C and 120 to 130 ° C.

As described above, the bare chip molded part 10
If 0 is manufactured, no tensile stress is applied to the wire 21 extending from the bare chip 2 to be sealed. as a result,
Disconnection of the wire 21 is prevented.

The common cell 10 is connected to the bare chips 2d, 2d,
Since the height is set to an appropriate value for each of the e, the amount of resin used for each of the bare chips 2d and 2e is made appropriate, and the yield of resin is improved. Further, since the common cell 10 is formed on the wire ball 22, the bare chips 2d and 2e can be molded in a small area, and the surface of the substrate 1 can be used effectively. As a result, the mounting density of electronic components is improved.

Further, the use of the high-viscosity sealing resin 20 and the formation of the partition for each bare chip by the partition 12 allow the sealing resin 20 to be filled well by dropping, without overflowing, thereby preventing the bare chips 2d, 2e The required resin thickness can be secured every time. Further, it becomes easy to adjust the amount of the sealing resin 20 to be dropped.

Also, in the next step after the bare chip sealing, even if it is heated for mounting other electronic parts, at least the expansion of the sealing resin 20 is effectively suppressed.
Disconnection of the wire 21 is prevented.

That is, if manufactured by the above manufacturing method, the bare chips 2d and 2e of various sizes can be
1 can be compactly and easily mounted without disconnection. Therefore, the bare chip molded component 100 manufactured by such a method has excellent quality characteristics such as compactness with little wire breakage.

(Embodiment 2) Also, as in a bare chip molded part 200 shown in FIG. 5, the wires 21f and 21g of the bare chips 2f and 2g are alternately bonded on the same circuit, and these wire balls 22f and 22g are Alternatively, the common cell 10 may be formed. According to such a configuration, the bare chips 2f and 2g can be compactly molded while maintaining the same effects as in the first embodiment, so that the electronic component mounting density of the substrate 1 can be further improved.

(Embodiment 3) Also, as in the bare chip molded part 300 shown in FIG. 6, the sealing resin 20 is filled and cured beyond the partition 12 to form the sealing resin layer 20a. Good. Even in such a configuration, the characteristics of the sealing resin 20 having a high viscosity and a low expansion coefficient are utilized, and the disconnection of the wire 21 can be effectively prevented.

[0054]

As described above, according to the method for producing a bare chip molded part and the bare chip molded part produced by the method according to the present invention, the bare chip is sealed with a resin having a low expansion coefficient. No tensile stress is applied to the extending wire. As a result, disconnection of the wire can be prevented, and the quality of the bare chip molded component can be improved. In addition, since the inside of the resin wall is partitioned by partitions and high-viscosity resin is dropped for each partition to manufacture the resin, the resin is unlikely to overflow from the inside of the partition, and as a result, compact molding can be performed, and electronic component mounting on the substrate can be performed. Density can be improved. Further, since the amount of resin is adjusted according to the height of the partition, the amount of dropped resin can be adjusted to an appropriate amount, the yield of resin can be improved, and the manufacturing cost can be reduced.

According to the method for manufacturing a bare chip molded part and the bare chip molded part manufactured by the method according to the next invention, even if the base of the wire of the bare chip is covered with a resin wall (first resin), the first resin can be used. And the second
The wire passes through the interface with the resin, but the first
Since the expansion coefficients of the resin and the second resin are substantially the same, no tensile stress is applied to the wire. Therefore, disconnection of the wire can be prevented, and peeling of the bonding portion at the root can also be prevented.

According to the method for manufacturing a bare chip molded component according to the next invention and the bare chip molded component manufactured by the method, wires extending from a plurality of bare chips are bonded on the same circuit on a substrate, and a part of the wires is formed. Since the members are simultaneously covered with the first resin, the mounting density can be increased while preventing wire breakage.

According to the method for producing a bare chip molded part according to the next invention and the bare chip molded part produced by the method, a resin wall and a partition wall are formed of a first resin having a high viscosity and a low expansion coefficient. The second resin having the same component as the first resin was filled in the resin wall. For this reason, wire breakage can be effectively prevented, the quality of bare chip molded parts can be improved, and resin can be prevented from overflowing, so that the mounting space for bare chips is compact and the mounting density of electronic components on the board is reduced. Can be improved.

According to the method for manufacturing a bare chip molded part according to the next invention and the bare chip molded part manufactured by the method, the resin wall and the partition wall have a height corresponding to the size of each bare chip. Can be easily adjusted, and the yield of resin is improved. As a result, the cost of the bare chip molded part can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a structure of a bare chip molded part according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA ′ shown in FIG.

FIG. 3 is a flowchart showing a manufacturing process of the bare chip molded part of the present invention.

FIG. 4 is an enlarged view of a part H shown in FIG. 2;

FIG. 5 is an explanatory view showing a structure of a bare chip molded part according to a second embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a structure of a bare chip molded part according to a third embodiment of the present invention.

FIG. 7 is an explanatory view showing the structure of a conventional bare chip molding component.

[Explanation of symbols]

100 bare chip molded parts, 1 substrate, 2 bare chips, 21 wires, 11 dam frames, 12 partitions,
Reference Signs List 10 common cell, 20 sealing resin, 20a sealing resin layer 200 bare chip molded part, 300 bare chip molded part.

Claims (8)

(57) [Claims] 1. A low-expansion, high-viscosity first resin,
A step of simultaneously forming a resin wall around a plurality of bare chips and a partition wall for partitioning the inside of the resin wall in units of the bare chips; and a second resin having an expansion coefficient and a viscosity substantially equal to those of the first resin. And a step of sealing the bare chip by heating and curing the first resin and the second resin substantially simultaneously, and disposing a plurality of bare chips having different sizes. In this case, a method of manufacturing a bare chip molded part, wherein the resin wall and the partition wall are formed at a height corresponding to the size of each bare chip. 2. A step of forming a resin wall or a partition wall so that a part of a wire extending from a bare chip is filled with the first resin, and another part of the wire is filled with the second resin. The method according to claim 1, further comprising: a step of filling the inside of the resin wall, and a step of heating and curing the first resin and the second resin substantially simultaneously to seal the bare chip. A method for producing a bare chip molded part as described in the above. 3. When a plurality of bare chips are provided, a resin wall or a partition wall is formed of the first resin so that a part of wires extending from a predetermined bare chip is simultaneously buried. A method for producing a bare chip molded part according to claim 1. 4. A resin wall formed around a bare chip, a first resin constituting a partition wall for partitioning the inside of the resin wall for each bare chip, and the bare chip being filled and cured in the resin wall. When the second resin for sealing is at least approximately the same expansion coefficient, and is made of a high-viscosity resin, and a plurality of bare chips having different sizes are provided, the resin wall and the partition wall are attached to each bare chip. Bare chip molded parts characterized by the appropriate height. 5. The bare chip molded part according to claim 4, wherein a wire extending from a bare chip passes through an interface between the first resin and the second resin. 6. The structure according to claim 4, wherein when a plurality of bare chips are provided, a part of wires extending from a predetermined bare chip is embedded in the first resin. Bare chip mold parts. 7. A resin wall having a high viscosity and a low expansion coefficient around a plurality of bare chips having different sizes and on a wire ball around the bare chip. Forming a partition wall, and filling the inside of the resin wall with a second resin having substantially the same main component as the resin wall and the partition wall; and forming the first resin and the second resin. A step of sealing the bare chip by heating and curing the resin substantially simultaneously, wherein the resin wall and the partition wall have a height corresponding to the size of each bare chip. Method. 8. A resin wall formed around a plurality of bare chips having different sizes and on a wire ball around the bare chip, and a partition wall for partitioning the inside of the resin wall,
The resin wall is formed of a first resin having a high viscosity and a low expansion coefficient, and the inside of the resin wall is filled with a second resin composed of the same main component as the resin wall and the partition wall. A bare chip molded part, wherein the partition wall has a height corresponding to the size of each bare chip.