JP3050224B1 - Resin-sealed semiconductor device and lead terminal partial coating method - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To improve a withstand voltage between lead terminals of a resin-sealed semiconductor device at a high level. SOLUTION: A resin-sealed semiconductor device including a resin-sealed body (1) and a plurality of lead terminals (2 to 6) derived from the resin-sealed body (1) is provided with lead terminals (2 to 6). 6) Insulated tube (7) attached to each, resin sealed body (1) and insulated tube
And (7) an insulating adhesive (8). Since the insulating tube (7) is bonded to the resin sealing body (1) by the insulating adhesive (8), the withstand voltage is stably and surely improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-sealed semiconductor device having a high withstand voltage between lead terminals and a method of partially covering the lead terminals.

[0002]

2. Description of the Related Art A semiconductor device in which a plurality of lead terminals are led out of a resin sealing body as an envelope is known. For example, Japanese Utility Model Application No. 53-167163 (Japanese Utility Model Application Laid-Open No. 55-849)
No. 57) discloses a resin-sealed semiconductor device in which a semiconductor element and a part of its external lead are wrapped with a synthetic resin. In this resin-encapsulated semiconductor device, a protrusion made of resin is formed on the resin surface between adjacent external lead leads, and even if the external lead leads are corroded and a product containing a large amount of metal ions is generated, diffusion of metal ions and The protrusion prevents the insulation resistance of the resin surface from deteriorating.

[0003]

By the way, in a power semiconductor device in which a large voltage is applied between adjacent lead terminals, it is necessary to further ensure a withstand voltage between the adjacent lead terminals. As a means of increasing the dielectric strength between the lead terminals, it is conceivable to attach an insulating tube to the lead terminal. However, even if the insulating tube is simply attached, discharge occurs through the gap between the tube and the resin sealing body. May occur and may not be sufficient. Accordingly, an object of the present invention is to provide a resin-encapsulated semiconductor device capable of improving the dielectric strength between adjacent lead terminals at a high level and a method of partially covering the lead terminals.

[0004]

A resin-encapsulated semiconductor device according to the present invention comprises a resin-encapsulated body (1) and a plurality of lead terminals (2 to 6) derived from the resin-encapsulated body (1). , Lead terminals (2 to 6)
The insulating tube (7) attached to each of the
Insulating adhesive (8) for bonding (1) and insulating tube (7)
And Since the insulating tube (7) is bonded to the resin sealing body (1) by the insulating adhesive (8), the withstand voltage is stably and surely improved. Further, it is possible to prevent corrosion due to a chemical change on the resin sealing body (1) side of the lead terminals (2 to 6) to which the insulating tube (7) is attached and an electrical short circuit accident due to contact with the outside. Further, it is possible to prevent the insulating tube (7) coming into close contact with the lead terminals (2 to 6) from falling off from the lead terminals (2 to 6).

[0005] The insulating tube (7) is formed of a material selected from vinyl chloride resin and polyamide resin.
Insulating adhesives (8) include thermoplastic polyamides, thermoplastic adhesives such as acrylic adhesives, thermosetting adhesives such as epoxy resins, pressure-sensitive adhesives such as acrylic pressure-sensitive adhesives, and thermoplastic resins. It is formed of a material selected from anaerobic adhesives such as hot melt adhesives and cyanoacrylate adhesives mainly composed of Each of the lead terminals (2 to 6) is a resin seal
(1) wide portion formed on the side (2a ~ 6a), and a narrow portion (2b ~ 6b) of a certain width formed on the side separated from the resin sealing body (1),
It has step portions (2c to 6c) formed between the wide portions (2a to 6a) and the narrow portions (2b to 6b). The insulating tube (7) includes the entire wide portions (2a to 6a) of the lead terminals (2 to 6) and the step portions (2c
6c) and the wide portion (2a to 6a) side of the narrow portion (2b to 6b), and is adhered to the resin sealing body (1). Insulating adhesive (8)
Thereby, the insulating tube (7) is adhered to the resin sealing body (1), so that a high withstand voltage can be obtained. Also, insulating tube
(7) completely covers the wide portions (2a to 6a) of the lead terminals (2 to 6) and further covers the narrow portions (2b to 6b).
The creepage distance between (2 to 6) is effectively increased, and a high level of withstand voltage effect is obtained in combination with the bonding effect. The insulating tube (7) is a cylindrical tube formed of a heat-shrinkable resin, and has a relatively large diameter and lead terminals (2 to
The large diameter portion (7a) surrounding the wide portion (2a-6a) of the 6) and the small diameter portion (2b-6b) having a relatively small diameter and surrounding the narrow portion (2b-6b) of the lead terminal (2-6). 7b) and an intermediate portion formed between the large diameter portion (7a) and the small diameter portion (7b) and surrounding the step portion (2c to 6c).
(7c). Insulating adhesive (8), insulating tube (7)
The gap formed between the resin sealing body (1) and the resin sealing body (1) is closed. Since the gap between the insulating tube (7) and the resin sealing body (1) is completely filled with the insulating adhesive (8), a high level of dielectric strength is achieved.

The method for partially covering lead terminals of a resin-encapsulated semiconductor device according to the present invention comprises a resin encapsulant (1) and a resin encapsulant (1).
A step of preparing a resin-encapsulated semiconductor device having a plurality of lead terminals (2 to 6) derived from a resin-encapsulated semiconductor device; Insulating adhesive (8)
Applying an insulating tube (7) to the lead terminals (2 to 6) coated with the insulating adhesive (8) in a state where the insulating adhesive (8) is not cured; and Curing the conductive adhesive (8) and bonding the insulating tube (7) to the resin sealing body (1). After applying the insulating adhesive (8), the insulating tube (7) is attached to the lead terminals (2 to 6), so the gap between the insulating tube (7) and the resin sealing body (1) is The insulating adhesive (8) can be reliably filled.

In an embodiment of the present invention, an insulating adhesive
(8) the step of bonding the insulating tube (7) to the resin sealing body (1) in an airtight or liquid-tight manner, and the insulating tube (7) is connected to the lead terminals (2 to 6) Step of temporarily fixing to the resin sealing body (1) above, airtight or liquid tight sealing between the insulating tube (7) and the resin sealing body (1) with the insulating adhesive (8) Process, a step of closing a gap formed between the insulating tube (7) and the resin sealing body (1) with the insulating adhesive (8), and connecting the insulating tube (7) to the lead terminals (2 to 6). Depending on the pressure when mounting on the insulating tube, a step of filling a part of the insulating adhesive (8) inside the insulating tube (7) or the insulating tube
The method may include a step of subjecting (7) and the insulating adhesive (8) to heat treatment to harden the insulating adhesive (8) and simultaneously heat-shrink the insulating tube (7). When the curing of the insulating adhesive (8) and the heat shrinkage of the insulating tube (7) are performed in the same step, good productivity can be obtained.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a resin-sealed semiconductor device according to the present invention applied to a power semiconductor device and a method of partially covering lead terminals of the resin-sealed semiconductor device according to the present invention are shown in FIGS.
Referring to FIG.

As shown in FIG. 1, a semiconductor device according to the present invention comprises a resin sealing body (1), a plurality of lead terminals (2 to 6) derived from the resin sealing body (1), and each lead. A short cylindrical insulating tube (7) attached to the terminals (2 to 6) and a resin seal
Insulating adhesive (8) for bonding (1) and insulating tube (7)
And The resin sealing body (1) surrounds the entire surface of the support plate (not shown) or the resin sealing body (1) on the lower surface side of the support plate.
And is formed by a well-known resin molding method. For the insulating tube (7), for example, a vinyl chloride resin or a polyamide resin can be used. Insulating adhesive
(8) has the property of being cured by heat treatment, aging, pressure bonding, or oxidation, and has a single component or a mixture of a plurality of components.
It may contain a liquid component. Insulating adhesive (8) is, for example,
Thermoplastic polyamides, thermoplastic adhesives such as acrylic adhesives, thermosetting adhesives such as epoxy resins, pressure-sensitive adhesives such as acrylic pressure-sensitive adhesives, hot melt adhesives mainly composed of thermoplastic resins, An anaerobic adhesive such as a cyanoacrylate adhesive can be used, but a good adhesive property to the resin sealing body (1) is required, so that a thermosetting resin such as an epoxy resin or a hot melt adhesive is used. It is desirable to use agents.

The lead terminals (2 to 6) are led out from one end of the resin sealing body (1) in parallel with each other, and are perpendicular to the lead-out direction in conformity with the inch pitch of a through hole of a printed board (not shown). It is arranged in a certain direction with a certain distance.
Each of the plurality of lead terminals (2 to 6) is formed with a wide portion (2a to 6a) formed on the resin sealing body (1) side and a fixed width on a side separated from the resin sealing body (1). Narrow part (2b-6b) and wide part
(2a to 6c) and a stepped portion (2c to 6c) formed in a tapered shape between the narrow portion (2b to 6b). The insulating tube (7)
The entire wide part (2a to 6a) of each lead terminal (2 to 6) and the step
(2c to 6c) and the wide portion (2a to 6a) side of the narrow portion (2b to 6b) are adhered to the resin sealing body (1) in an airtight or liquid tight manner.

The insulating tube (7) is a cylindrical heat-shrinkable tube, and has a relatively large diameter and surrounds the wide portions (2a to 6a) of the lead terminals (2 to 6) as shown in the figure. The large diameter portion (7a), the small diameter portion (7b) having a relatively small diameter and surrounding the narrow portion (2b-6b) of the lead terminal (2-6), the large diameter portion (7a) and the small diameter portion (7b) and an intermediate portion (7c) surrounding the step portions (2c to 6c). Insulating adhesive (8)
Are provided near the lead-out portions of the lead terminals (2 to 6) of the resin sealing body (1), and adhere the insulating tube (7) and the resin sealing body (1), as well as the insulating tube (7). ) And the resin sealing body (1).

When attaching the insulating tube (7) shown in FIG. 1 to the lead terminals (2 to 6), as shown in FIG. 2, the resin sealing body (1) and the resin sealing body (1) A semiconductor device having a plurality of lead terminals (2 to 6) derived from is prepared. Next, as shown in FIG. 3, using a supply thin tube such as a syringe-shaped applicator or a syringe, a liquid-like liquid is formed in a loop shape in the vicinity of the lead-out portion of the lead terminal (2 to 6) of the resin sealing body (1). Apply an insulating adhesive (8). Since the application step uses the supply thin tube, it can be easily performed.

Next, as shown in FIG.
When the insulating tube (7) is attached to the lead terminals (2 to 6) coated with the insulating adhesive (8) in a state where (8) is not cured, the area around the lead-out part of each wide part (2a to 6a) Lead terminals (2 to 4) depending on the viscosity of the insulating adhesive (8) applied to the resin sealing body (1).
6) The annular end of the cylindrical insulating tube (7) mounted thereon is temporarily fixed to the resin sealing body (1) along the entire circumference. At this time, the insulating adhesive (8) air-tightly or liquid-tightly seals between the entire periphery of the annular end of the insulating tube (7) and the resin sealing body (1). ) And the resin seal (1) are completely closed. Insulating tube (7)
The inside of the insulating tube (7) may be filled with a part of the insulating adhesive (8) by the pressure at the time of mounting on the lead terminals (2 to 6). Insulating tube (7) with lead terminals (2-6)
When attached to the tube, as shown in FIG.
(7) surrounds the entire wide portion (2a to 6a) of the lead terminals (2 to 6) and the wide side of the narrow portion (2b to 6b), and has an annular shape with a uniform diameter from one end to the other end. Has a cross section. Fig. 1
Is slightly larger than the diameter of the insulating tube (7) on the resin sealing body (1) side shown in FIG.

Next, the insulating tube (7) and the insulating adhesive (8) are subjected to a heat treatment to harden the insulating adhesive (8) and, at the same time, to thermally shrink the insulating tube (7). A step (7a) is formed in the insulating tube (7). Thereby, the resin sealing body (1) and the tube (7) are fixed, and the contracted tube (7) is formed with the large-diameter portion (7a) and the small-diameter portion (7b), and the lead terminals (2 to 7) are formed. 6), and the insulating tube (7) can be air-tightly or liquid-tightly attached to the lead terminals (2 to 6) as shown in FIG.

In this embodiment, the following effects can be obtained. [1] Since the insulating tube (7) is bonded to the resin sealing body (1) by the insulating adhesive (8), the withstand voltage between the lead terminals (2 to 6) is stably and surely improved. [2] Since the insulating adhesive (8) adheres the annular end of the insulating tube (7) to the resin sealing body (1) in an air-tight or liquid-tight manner along the entire circumference, a high dielectric strength is obtained. . [3] Since the gap between the insulating tube (7) and the resin sealing body (1) is completely filled with the insulating adhesive (8), a high level of dielectric strength is achieved. [4] The insulating tube (7) is the wide part of the lead terminals (2 to 6)
(2a to 6a) is completely covered, and further to the narrow portion (2b to 6b), effectively increasing the creepage distance between the wide portions (2a to 6a) of the lead terminals (2 to 6). A high level of withstand voltage effect can be obtained in combination with the effects of [1] and [2]. [5] Insulating tube (7) closely attached to lead terminals (2 to 6)
From the lead terminals (2 to 6) can be prevented. [6] Insulating tube (7) after applying insulating adhesive (8)
Is attached to the lead terminals (2 to 6).
The gap between (7) and the resin sealing body (1) can be reliably filled with the insulating adhesive (8). [7] Since the curing of the insulating adhesive (8) and the heat shrinkage of the insulating tube (7) are performed in the same step, the productivity is excellent. [8] Lead terminal (2 ~
6) It is possible to prevent corrosion due to chemical change on the resin sealing body (1) side and electrical short circuit accident due to contact with the outside.

The above embodiment of the present invention can be modified. For example, without heating the insulating adhesive (8), leaving it for a predetermined time period of several seconds to several minutes,
(7) may be pressed against the insulating adhesive (8) to be cured.

[0017]

As described above, according to the present invention, a high withstand voltage between the lead terminals can be obtained, so that the failure of the resin-encapsulated semiconductor device is avoided, the reliability is improved, and the resin-encapsulated semiconductor device is improved. Life can be extended.

[Brief description of the drawings]

FIG. 1 is a plan view of a resin-sealed semiconductor device according to the present invention.

FIG. 2 is a plan view of the resin-encapsulated semiconductor device before the insulating tube is mounted.

FIG. 3 is a plan view of the resin-encapsulated semiconductor device in a state where an insulating adhesive is applied.

FIG. 4 is a plan view showing a resin-encapsulated semiconductor device before heating with an insulating tube attached.

[Explanation of symbols]

(1) ・ ・ Resin sealed body, (2-6) ・ ・ Lead terminal, (2a〜
6a) ・ ・ Wide part, (2b〜6b) ・ ・ Narrow part, (2c〜6c) ・
・ Stepped part, (7) ・ ・ Insulated tube, (7a) ・ ・ Large diameter part, (7b) ・ ・ Small diameter part, (7c) ・ ・ Intermediate part, (8) ・ ・
Insulating adhesive,

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 23/28 H01L 23/50

Claims (13)

(57) [Claims] 1. A resin-sealed semiconductor device comprising: a resin-sealed body; and a plurality of lead terminals led out of the resin-sealed body, wherein: an insulating tube mounted on each of the lead terminals;
A resin-sealed semiconductor device comprising an insulating adhesive for bonding the resin-sealed body and an insulating tube. 2. The resin-sealed semiconductor device according to claim 1, wherein said insulating tube is formed of a material selected from a vinyl chloride resin and a polyamide resin. 3. The insulating adhesive includes a thermoplastic polyamide, a thermoplastic adhesive such as an acrylic adhesive, a thermosetting adhesive such as an epoxy resin, a pressure-sensitive adhesive such as an acrylic pressure-sensitive adhesive, The resin-encapsulated semiconductor device according to claim 1, wherein the resin-encapsulated semiconductor device is formed of a material selected from an anaerobic adhesive such as a hot melt adhesive mainly composed of a thermoplastic resin and a cyanoacrylate adhesive. 4. Each of the lead terminals has a wide portion formed on the resin sealing body side, a narrow portion having a constant width formed on a side separated from the resin sealing body, and a wide portion and a width. A step portion formed between the narrow portion and the narrow portion; the insulating tube surrounds the entire wide portion and the step portion of each of the lead terminals, and surrounds the wide portion side of the narrow portion; 4. Any one of claims 1 to 3, which is adhered to a sealing body.
Item 13. A resin-sealed semiconductor device according to item 9. 5. An insulating tube comprising a cylindrical tube formed of a heat-shrinkable resin, having a relatively large diameter and surrounding a wide portion of a lead terminal;
5. A small diameter portion having a relatively small diameter and surrounding the narrow portion of the lead terminal, and an intermediate portion formed between the large diameter portion and the small diameter portion and surrounding the step portion. The resin-encapsulated semiconductor device according to any one of the above. 6. The insulating adhesive closes a gap formed between the insulating tube and the resin sealing body.
6. The resin-encapsulated semiconductor device according to any one of Items 5 to 5. 7. A step of preparing a resin-encapsulated semiconductor device having a resin-encapsulated body and a plurality of lead terminals derived from the resin-encapsulated body; Applying a liquid insulating adhesive to the lead terminal; attaching the insulating tube to the lead terminal to which the insulating adhesive is applied in a state where the insulating adhesive is not cured; Curing the resin tube and bonding the insulating tube to the resin sealing body. 8. The method according to claim 7, further comprising the step of air-tightly or liquid-tightly bonding the insulating tube to the resin sealing body with the insulating adhesive. . 9. The resin-encapsulated semiconductor device according to claim 7, further comprising a step of temporarily fixing the insulative tube to the resin encapsulant on the lead terminal by the viscosity of the insulative adhesive. Lead terminal partial coating method. 10. The resin sealing according to claim 7, further comprising a step of air-tightly or liquid-tightly sealing between the insulating tube and the resin sealing body with the insulating adhesive. Partial coating method for lead terminals of fixed semiconductor devices. 11. The resin sealing according to claim 7, further comprising a step of closing a gap formed between the insulating tube and the resin sealing body with the insulating adhesive. Partial coating method for lead terminals of fixed semiconductor devices. 12. The method according to claim 7, further comprising a step of filling a part of the insulating adhesive inside the insulating tube by a pressure when the insulating tube is mounted on the lead terminal. Item 14. The method for partially covering lead terminals of a resin-encapsulated semiconductor device according to item 9. 13. The method according to claim 7, further comprising a step of subjecting the insulating tube and the insulating adhesive to a heat treatment to cure the insulating adhesive and simultaneously heat-shrink the insulating tube. 2. The method for partially covering lead terminals of a resin-sealed semiconductor device according to claim 1.