JPH0845974A - Semiconductor device - Google Patents

Abstract

PURPOSE:To stabilize the production while enhancing the reliability. CONSTITUTION:A resist 19, exhibiting lower adhesion to resin than a circuit board 11, is formed on the surface of the circuit board 11 except the part for mounting a semiconductor element 12, the bonding pad 14 and the outer connection terminal 16, for example. Furthermore, a plating layer 21 exhibiting lower adhesion to the resin than the resist 19 is formed at a part, on the surface of the circuit board 11, corresponding to the gate part of a molding die. Since the adhesion to the resin is varied, the gate break performance is enhanced in the single side transfer molding while preventing the mold resin 20 from being stripped from the circuit board 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, for example, a circuit board on which resin is sealed, and more particularly to a single-sided transfer mold type MCM (multi-chip type).
Module).

[0002]

2. Description of the Related Art In recent years, MCMs have been widely used in small communication devices and small computers. This MCM has a structure in which a plurality of semiconductor elements are mounted on a circuit board, and the mounting surface is sealed with potting resin.

In the MCM having such a structure, high reliability is required as well as high density and miniaturization of mounting. FIG. 5 shows a schematic configuration of a conventional MCM. It should be noted that FIG. 1A shows an MC through which the element mounting portion is seen through.
It is a top view of M, and the figure (b) is a sectional view which similarly follows the VV 'line.

That is, in the conventional MCM, a plurality of (here, two) semiconductor elements 2 are mounted on the circuit board 1,
They are configured to be sealed with resin 4.
Each electrode pad 2a of the semiconductor element 2 is connected to each bonding pad 3 by a bonding wire 5, and a part of the pad 3 is connected to an external connection terminal 7 via an external connection wiring 6. Further, some of the bonding pads 3 are connected to each other via inter-element connection wiring 8. The external connection wiring 6 and the inter-element connection wiring 8 are formed by, for example, gold plating.

The sealing with the resin 4 is performed on the resist 9 formed in the region to be sealed, that is, the region excluding the mounting portion of the semiconductor element 2, the bonding pad 3 and the external connection terminal 7, and the adhesive 100. Frame 1 pasted through
It is performed by dropping a potting resin into 01 and curing the potting resin by heat treatment.

The MCM having such a structure is surface-mounted by connecting the external connection terminals 7 to the wiring on the mounting board (not shown) on the back surface of the circuit board 1.

However, in the case of the MCM having the above-mentioned structure, since the potting resin is used for sealing, the reliability of the MCM is higher than that of the transfer molding resin in terms of the adhesion between the circuit board 1 and the resin 4 and the moisture resistance. There was a problem that was bad.

Although encapsulation with a mold resin has been considered, there is a problem that production is not stable. That is, in the sealing with the mold resin, for example, the surface of the circuit board is covered with a mold, and the melted resin is filled from the gate into the mold. Then, when the resin is sufficiently cured, the mold is removed to try to seal with the molding resin (not shown).

However, the resist applied to the sealing area on the circuit board increases the adhesion between the circuit board and the resin, so that the work at the time of the gate break is difficult, that is, unnecessary resin formed on the gate portion is removed. At this time, there is a high possibility that the circuit board and the mold resin will peel off.

Further, the conventional MCM has an inter-element connection wiring 8
However, there is a problem in that it is not possible to confirm the operation between the semiconductor elements 2 even though a part of the gold is plated out from the outer periphery of the circuit board 1 in the form of a plated lead wire.

[0011]

As described above, in the conventional case, when the potting resin is used for sealing, reliability is poor in terms of adhesion and moisture resistance, and sealing with a mold resin is performed. There was a problem that the production was not stable when I tried to go.

Therefore, an object of the present invention is to provide a semiconductor device which can improve reliability and can be stably manufactured. Further, in the related art, there is a problem in that it is not possible to confirm the operation between the semiconductor elements mounted on the circuit board. Therefore, an object of the present invention is to provide a semiconductor device capable of easily confirming the operation between semiconductor elements mounted on a circuit board.

[0013]

To achieve the above object, in a semiconductor device of the present invention, a semiconductor device is mounted, and a circuit board provided with wirings connected to the semiconductor device, A resist applied on this circuit board,
The adhesiveness between the mold resin formed by transfer molding on the circuit board, including the resist, and the mold resin provided corresponding to the introduction portion of the mold resin of the circuit board is higher than that of the resist. It is composed of a low metal plating layer.

Further, in the semiconductor device of the present invention,
A circuit board on which a plurality of semiconductor chips are mounted, a connection wiring for connecting the semiconductor chips mounted on the circuit board to each other, a test terminal arranged at one end of the connection wiring, and the test terminal And a resist applied on one surface of the circuit board excluding the mounting portion of the semiconductor chip, a mold resin including the resist and transfer-molded on the circuit board, and the mold of the circuit board. Provided corresponding to the resin introduction part,
It is composed of a metal plating layer having lower adhesion to the mold resin than the resist.

[0015]

The present invention makes it possible to change the adhesiveness with the resin by the above-mentioned means, so that it is possible to improve the gate breakability and prevent the resin from separating from the circuit board. Moreover, after the plating, the connection wiring, which is unnecessary, can be effectively used.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic structure of a single-sided transfer mold type MCM according to the present invention.
It should be noted that FIG. 10A is a plan view of the MCM showing the element mounting portion as seen through, and FIG. 11B is a sectional view taken along line Ib-Ib ′.

That is, a plurality of, for example, two semiconductor elements 12 are mounted on the circuit board 11. The circuit board 11 is, for example, FR-4, FR-5, or B.
It is composed of T resin and the like. This circuit board 1
1 is provided with a bonding pad 14 to which the semiconductor element 12 is connected, an external connection terminal 16 and wirings 15 and 17 for connecting these to each other.

Each semiconductor element 12 has a plurality (here, 14
Individual) electrode pads 12a are provided, and each of the electrode pads 12a is individually connected to the bonding pad 14 via the bonding wire 13.

The bonding pads 14 are provided on the periphery of each mounting portion of the semiconductor element 12 so as to surround the respective semiconductor elements 12.
It is arranged so as to surround. A part of the bonding pad 14 is connected to the external connection terminal 16 via the external connection wiring 15. The external connection terminal 16 is formed by connecting the end portion on the front surface side and the end portion on the back surface side so as to surround the side surface of the circuit board 11.

Further, some of the bonding pads 14 are mutually connected to the bonding pads 14 of the same element 12 or another element 12 via inter-element connection wirings 17. One end (plating lead-out line) of the inter-element connection wiring 17 extends to the outer peripheral portion of the circuit board 11, and a connection pad 18 as a test terminal is arranged at the tip thereof.

The external connection wiring 15 and the inter-element connection wiring 17 are formed by, for example, gold plating. In this case, the gold plating of the external connection wiring 15 is grown using the external connection terminal 16 as a plating electrode, and
The inter-element connection wiring 17 is plated with gold by the connection pad 18 described above.
Is grown as an electrode for plating.

On the other hand, a resist 19 is applied on the surface of the circuit board 11 except the mounting portions of the semiconductor element 12, the bonding pads 14 and the external connection terminals 16. The resist 19 is CCR-23.
A thermosetting resin such as 2CV or CCR-232GV is used.

The circuit board 1 including the resist 19
A mold resin 20 is formed on the surface 1 by transfer molding (details will be described later). The mold resin 20 is a general resin material, for example, 10
00SR or 1000SV is used.

The portion of the circuit board 11 corresponding to the resin introduction portion (gate portion) of the mold resin 20 is
A plating layer 21 is formed which has lower adhesion to the mold resin 20 than the resist 19.

As the plating layer 21, for example, gold plating or silver plating, which has lower adhesiveness with the mold resin 20 than the resist 19 lower than that of the circuit board 11, is used.

That is, the degree of adhesion with the mold resin 20 is strongest in the circuit board 11, and then in the resist 1
9 and the plated layer 21 in this order. This plating layer 21
A slight clearance portion (0.05 to 0.1 mm) is provided between the mold resin 20 and the mold resin 20, and the resist 19 is formed up to this portion. This ensures workability for removing the unnecessary resin formed on the plated layer 21.

For example, the resist 19 is formed with a margin of 0.5 mm or more from the outer shape of the mold resin 20, is in contact with the plating layer 21, and prevents lateral leakage of the resin from the gate portion. Then, it is formed so as to surround both sides of the plating layer 21.

According to such a structure, that is, the single-sided transfer mold type MCM, the reliability as a semiconductor device is improved in terms of adhesion and moisture resistance as compared with the case where the potting resin is used for sealing. it can.

Moreover, the adhesion of the gate portion to the mold resin 20 is improved by the plating layer 21 and the resist 19 is used.
And the adhesiveness with the mold resin 20 can be lowered. Therefore, the work for removing the unnecessary resin in the gate portion at the time of the gate break becomes easy, and the problem that the circuit board 11 and the mold resin 20 are accidentally peeled off can be solved and the production can be stabilized. Become.

Further, by arranging the connection pad (exposed from the resist 19) 18 at the tip of the plated lead-out wire drawn out from one end of the inter-element connection wiring 17, conventionally, only for gold plating of the inter-element connection wiring 17. It is possible to effectively use the plated lead wires that were used and were completely unnecessary after plating. That is, it is possible to easily confirm the operation between the semiconductor elements 12 by using this plated lead wire.

FIG. 2 shows a method of forming the molding resin 20 by transfer molding of the above MCM. Here, the MCM shown in FIG.
It is shown as a cross section along the line.

The mold resin 20 is formed by first forming the mold 3 on the upper side of the circuit board 11 coated with the resist 19.
1 is fixed. The mold 31 is provided with a gate portion 31a for introducing the above-mentioned sealing resin, a cavity portion 31b for sealing the region excluding the external connection terminal 16 and the like with the mold resin 20, and the like. ing.

The resin in a molten state is poured into the mold 31 through the gate portion 31a. Then, the cavity 31b is filled. After the resin filled in the cavity portion 31b is sufficiently cured, the mold 31 is
It is removed from the circuit board 11.

Further, the resin hardened in the gate portion 31a is removed, and only the resin hardened in the cavity portion 31b is left, so that only the region excluding the external connection terminal 16 and the like has the mold resin 20. It is sealed by.

In this case, since the plating layer 21 is formed on the circuit board 11 corresponding to the gate portion 31a, the adhesion to the resin is weaker than that of the resist 19, and the resin is hardened at the gate portion 31a. The resin can be easily removed.

On the other hand, on the circuit board 11 corresponding to the cavity portion 31b, the resist 19 is formed on the portion excluding the mounting portion of the semiconductor element 12 and the bonding pad 14, so that it is cured in the cavity portion 31b. The resin, that is, the mold resin 20, is formed with high adhesion.

Therefore, it is possible to improve the gate breaking property at the time of the gate break and easily prevent the circuit board 11 and the mold resin 20 from being easily separated.

Here, the resist 19 in the above embodiment is used.
Alternatively, it may be formed to have an air vent structure. FIG. 3 shows an example of the resist 19 having an air vent structure. The figure (a)
A plan view of the resist 19 and a side view of the same are shown in FIG.

The resist 19 is, for example, the circuit board 1.
It is formed by four resist patterns 19b in which a resist removal pattern 19a in which no resist is present is provided on one diagonal.

Further, the resist pattern 19b is formed along the respective sides of the circuit board 11 in the resist pattern 19c.
Is provided. These resist removal patterns 19
The a and 19c may be provided at arbitrary positions as needed, depending on the amount and location of voids generated during transfer molding.

As a result, voids can be reduced,
The reliability can be improved. Further, since it is not necessary to provide the mold 31 with the air vent structure, the mold 31 can be manufactured at low cost, and the manufacturing cost can be reduced.

Further, the resist removal patterns 19a, 19
The c is not limited to the one that exposes the circuit board 11 (the resist does not exist), and it is also possible to change the thickness of the resist to form a cleaved shape (concave shape).

FIG. 4 shows an example in which the connection pad 18 is provided on the back surface of the circuit board 11 in the above MCM. It is to be noted that FIG. 10A is a plan view of the MCM as seen through the element mounting portion as seen from above, and FIG.
It is the top view seen from the bottom.

For example, the connection pad 18 is used for the circuit board 1.
On the back surface of No. 1, they are arranged between the external connection terminals 16. The inter-element connection wiring 1 is connected to the connection pad 18 via a through hole 41 formed in the circuit board 11.
One end of 7 (plated lead wire) is connected.

The gold plating of the inter-element connection wiring 17 is grown by using the connection pad 18 provided on the back surface of the circuit board 11 as a plating electrode. The external connection terminal 16 and the connection pad 18 are provided on the back surface of the circuit board 11.
A resist 42 is formed in a region other than that, and the inter-element connection wiring 17 and the through hole 41 are covered with the resist 42.

With such a configuration, as in the above-described embodiment, not only the operation confirmation between the semiconductor elements 12 can be easily performed, but also the user is made aware of the existence of the connection pad 18 used by the manufacturer. Never.

Further, the surface of the circuit board 11 can be effectively utilized by arranging the wirings 15 and 17. In the above embodiments, the MCM in which the semiconductor elements are bonded and connected via the wires has been described as an example, but the present invention is not limited to this and, for example, BGA (Ball Grid Array).
And LCC (Leadless Chip Carry)
It is also applicable to the MCM of the system. Of course, various modifications can be made without departing from the scope of the invention.

[0048]

As described above in detail, according to the present invention, it is possible to provide a semiconductor device which can improve reliability and can be stably manufactured. Further, it is possible to provide a semiconductor device capable of easily confirming the operation between the semiconductor elements mounted on the circuit board.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an outline of an MCM according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a method of forming a mold resin by transfer molding of the MCM.

FIG. 3 is a configuration diagram schematically showing an example of a resist used for MCM.

FIG. 4 is a plan view showing another configuration example of the MCM.

FIG. 5 is an M shown to explain the related art and its problems.
The schematic block diagram of CM.

[Explanation of symbols]

11 ... Circuit board, 12 ... Semiconductor element, 13 ... Bonding wire, 14 ... Bonding pad, 15 ... External connection wiring, 16 ... External connection terminal, 17 ... Inter-element connection wiring, 1
8 ... Connection pad, 19 ... Resist, 19a, 19c ... Resist missing pattern, 19b ... Resist pattern, 20
... Mold resin, 21 ... Plating layer, 31 ... Mold, 31a
... gate portion, 31b ... cavity portion, 41 ... through hole.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area // B29L 31:34

Claims (7)

[Claims] 1. A circuit board on which a semiconductor element is mounted and a wiring connected to the element is provided, a resist applied on the circuit board, and transfer molding on the circuit board including the resist. And a metal plating layer, which is provided corresponding to the introduction portion of the mold resin of the circuit board and has a lower adhesiveness with the mold resin than the resist. Semiconductor device. 2. The semiconductor device according to claim 1, wherein the resist is formed so as to surround a side of the metal plating layer. 3. The semiconductor device according to claim 1, wherein the resist has an air vent structure in which a concave portion is formed at least at a position facing the introduction portion of the mold resin. 4. A circuit board on which a plurality of semiconductor chips are mounted, a connection wiring for connecting the semiconductor chips mounted on the circuit board to each other, and a test terminal arranged at one end of the connection wiring. A resist applied on one surface of the circuit board excluding the test terminals and the mounting portion of the semiconductor chip; a mold resin including the resist and transfer-molded on the circuit board; A semiconductor device comprising: a metal plating layer provided on a substrate corresponding to the introduction portion of the mold resin, the metal plating layer having lower adhesion to the mold resin than the resist. 5. The semiconductor device according to claim 4, wherein the connection wiring is formed by plating. 6. The semiconductor device according to claim 5, wherein the plating is grown by using a test terminal arranged at one end of the connection wiring as a plating electrode. 7. The semiconductor device according to claim 4, wherein the test terminal is arranged on the other surface of the circuit board and is connected to the connection wiring via a through hole.