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Reason for gold lines on old ICs?
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A lot of older (ceramic) ICs have a gold-plated line extending from the die cover to the edge of the package. Did this serve a practical purpose or was it just bling?
I suspect that it might be what's left of the lead frame leading to the pad under the soldered die cover. It would hold the pad in position while the package was molded. Similarly, the gold plating on the pin-1 notch in the photo below is part of the trimmed lead frame. This is just a hypothesis; can anyone confirm?
Source: Wikipedia/Arnold Reinhold (CC/A-SA)
hardware chip
asked 18 hours ago
Alex Hajnal
3,23331131
add a comment |
up vote
16
down vote
favorite
A lot of older (ceramic) ICs have a gold-plated line extending from the die cover to the edge of the package. Did this serve a practical purpose or was it just bling?
I suspect that it might be what's left of the lead frame leading to the pad under the soldered die cover. It would hold the pad in position while the package was molded. Similarly, the gold plating on the pin-1 notch in the photo below is part of the trimmed lead frame. This is just a hypothesis; can anyone confirm?
Source: Wikipedia/Arnold Reinhold (CC/A-SA)
hardware chip
asked 18 hours ago
Alex Hajnal
3,23331131
add a comment |
up vote
16
down vote
favorite
up vote
16
down vote
favorite
A lot of older (ceramic) ICs have a gold-plated line extending from the die cover to the edge of the package. Did this serve a practical purpose or was it just bling?
I suspect that it might be what's left of the lead frame leading to the pad under the soldered die cover. It would hold the pad in position while the package was molded. Similarly, the gold plating on the pin-1 notch in the photo below is part of the trimmed lead frame. This is just a hypothesis; can anyone confirm?
Source: Wikipedia/Arnold Reinhold (CC/A-SA)
hardware chip
asked 18 hours ago
Alex Hajnal
3,23331131
A lot of older (ceramic) ICs have a gold-plated line extending from the die cover to the edge of the package. Did this serve a practical purpose or was it just bling?
I suspect that it might be what's left of the lead frame leading to the pad under the soldered die cover. It would hold the pad in position while the package was molded. Similarly, the gold plating on the pin-1 notch in the photo below is part of the trimmed lead frame. This is just a hypothesis; can anyone confirm?
Source: Wikipedia/Arnold Reinhold (CC/A-SA)
hardware chip
hardware chip
asked 18 hours ago
Alex Hajnal
3,23331131
asked 18 hours ago
Alex Hajnal
3,23331131
edited 14 hours ago
asked 18 hours ago
Alex Hajnal
3,23331131
asked 18 hours ago
Alex Hajnal
3,23331131
asked 18 hours ago
Alex Hajnal
3,23331131
3,23331131
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
up vote
17
down vote
It's a ground wire. The way ICs were manufactured back then had the metal cover placed over the die as the last step, and grounding it helps protect the die from static shock and interference.
If you look closely you can see the solder that bonds the strip to the die cover. If you check continuity you will find that both are connected to the IC's ground plane and ground pin(s).
answered 18 hours ago
user
2,577314
When would it be grounded though? The line doesn't connect to any pin.
– Alex Hajnal
18 hours ago
2
It connects to the exposed ground plane on the side of the IC.
– user
18 hours ago
2
I guess they don't have to be, there is a cost to it so if it wasn't necessary for that particular part they might skip it. It depends how sensitive it is, what the application is, that kind of thing. Manufacturers quickly moved to plastic packages once they became practical.
– user
17 hours ago
1
MBA810 is a high power (up to 10W depending on manufacturer) amplifier. The 'wings' aren't ment as ground (although they are connected), but for cooling. They do not go over the IC (like the cap) but below to transfer heat.
– Raffzahn
12 hours ago
2
Also, the metal cap is never atatched to the die inside, as the upper side of a die contains circuitry and a metal cap will carry a high chance of shortcuting. Heat for dissapation is taken from the lower side. That's why modern CPUs are flip mounted, so heat transfer can be aproved ( also it allows more connections, as now pins may also connect to pads inside the chip, not just aroudn the border.
– Raffzahn
12 hours ago
|
show 8 more comments
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
17
down vote
It's a ground wire. The way ICs were manufactured back then had the metal cover placed over the die as the last step, and grounding it helps protect the die from static shock and interference.
If you look closely you can see the solder that bonds the strip to the die cover. If you check continuity you will find that both are connected to the IC's ground plane and ground pin(s).
answered 18 hours ago
user
2,577314
When would it be grounded though? The line doesn't connect to any pin.
– Alex Hajnal
18 hours ago
2
It connects to the exposed ground plane on the side of the IC.
– user
18 hours ago
2
I guess they don't have to be, there is a cost to it so if it wasn't necessary for that particular part they might skip it. It depends how sensitive it is, what the application is, that kind of thing. Manufacturers quickly moved to plastic packages once they became practical.
– user
17 hours ago
1
MBA810 is a high power (up to 10W depending on manufacturer) amplifier. The 'wings' aren't ment as ground (although they are connected), but for cooling. They do not go over the IC (like the cap) but below to transfer heat.
– Raffzahn
12 hours ago
2
Also, the metal cap is never atatched to the die inside, as the upper side of a die contains circuitry and a metal cap will carry a high chance of shortcuting. Heat for dissapation is taken from the lower side. That's why modern CPUs are flip mounted, so heat transfer can be aproved ( also it allows more connections, as now pins may also connect to pads inside the chip, not just aroudn the border.
– Raffzahn
12 hours ago
|
show 8 more comments
up vote
17
down vote
It's a ground wire. The way ICs were manufactured back then had the metal cover placed over the die as the last step, and grounding it helps protect the die from static shock and interference.
If you look closely you can see the solder that bonds the strip to the die cover. If you check continuity you will find that both are connected to the IC's ground plane and ground pin(s).
answered 18 hours ago
user
2,577314
When would it be grounded though? The line doesn't connect to any pin.
– Alex Hajnal
18 hours ago
2
It connects to the exposed ground plane on the side of the IC.
– user
18 hours ago
2
I guess they don't have to be, there is a cost to it so if it wasn't necessary for that particular part they might skip it. It depends how sensitive it is, what the application is, that kind of thing. Manufacturers quickly moved to plastic packages once they became practical.
– user
17 hours ago
1
MBA810 is a high power (up to 10W depending on manufacturer) amplifier. The 'wings' aren't ment as ground (although they are connected), but for cooling. They do not go over the IC (like the cap) but below to transfer heat.
– Raffzahn
12 hours ago
2
Also, the metal cap is never atatched to the die inside, as the upper side of a die contains circuitry and a metal cap will carry a high chance of shortcuting. Heat for dissapation is taken from the lower side. That's why modern CPUs are flip mounted, so heat transfer can be aproved ( also it allows more connections, as now pins may also connect to pads inside the chip, not just aroudn the border.
– Raffzahn
12 hours ago
|
show 8 more comments
up vote
17
down vote
up vote
17
down vote
It's a ground wire. The way ICs were manufactured back then had the metal cover placed over the die as the last step, and grounding it helps protect the die from static shock and interference.
If you look closely you can see the solder that bonds the strip to the die cover. If you check continuity you will find that both are connected to the IC's ground plane and ground pin(s).
answered 18 hours ago
user
2,577314
It's a ground wire. The way ICs were manufactured back then had the metal cover placed over the die as the last step, and grounding it helps protect the die from static shock and interference.
If you look closely you can see the solder that bonds the strip to the die cover. If you check continuity you will find that both are connected to the IC's ground plane and ground pin(s).
answered 18 hours ago
user
2,577314
answered 18 hours ago
user
2,577314
answered 18 hours ago
user
2,577314
answered 18 hours ago
user
2,577314
2,577314
When would it be grounded though? The line doesn't connect to any pin.
– Alex Hajnal
18 hours ago
2
It connects to the exposed ground plane on the side of the IC.
– user
18 hours ago
2
I guess they don't have to be, there is a cost to it so if it wasn't necessary for that particular part they might skip it. It depends how sensitive it is, what the application is, that kind of thing. Manufacturers quickly moved to plastic packages once they became practical.
– user
17 hours ago
1
MBA810 is a high power (up to 10W depending on manufacturer) amplifier. The 'wings' aren't ment as ground (although they are connected), but for cooling. They do not go over the IC (like the cap) but below to transfer heat.
– Raffzahn
12 hours ago
2
Also, the metal cap is never atatched to the die inside, as the upper side of a die contains circuitry and a metal cap will carry a high chance of shortcuting. Heat for dissapation is taken from the lower side. That's why modern CPUs are flip mounted, so heat transfer can be aproved ( also it allows more connections, as now pins may also connect to pads inside the chip, not just aroudn the border.
– Raffzahn
12 hours ago
|
show 8 more comments
When would it be grounded though? The line doesn't connect to any pin.
– Alex Hajnal
18 hours ago
2
It connects to the exposed ground plane on the side of the IC.
– user
18 hours ago
2
I guess they don't have to be, there is a cost to it so if it wasn't necessary for that particular part they might skip it. It depends how sensitive it is, what the application is, that kind of thing. Manufacturers quickly moved to plastic packages once they became practical.
– user
17 hours ago
1
MBA810 is a high power (up to 10W depending on manufacturer) amplifier. The 'wings' aren't ment as ground (although they are connected), but for cooling. They do not go over the IC (like the cap) but below to transfer heat.
– Raffzahn
12 hours ago
2
Also, the metal cap is never atatched to the die inside, as the upper side of a die contains circuitry and a metal cap will carry a high chance of shortcuting. Heat for dissapation is taken from the lower side. That's why modern CPUs are flip mounted, so heat transfer can be aproved ( also it allows more connections, as now pins may also connect to pads inside the chip, not just aroudn the border.
– Raffzahn
12 hours ago
When would it be grounded though? The line doesn't connect to any pin.
– Alex Hajnal
18 hours ago
When would it be grounded though? The line doesn't connect to any pin.
– Alex Hajnal
18 hours ago
2
2
It connects to the exposed ground plane on the side of the IC.
– user
18 hours ago
It connects to the exposed ground plane on the side of the IC.
– user
18 hours ago
2
2
I guess they don't have to be, there is a cost to it so if it wasn't necessary for that particular part they might skip it. It depends how sensitive it is, what the application is, that kind of thing. Manufacturers quickly moved to plastic packages once they became practical.
– user
17 hours ago
I guess they don't have to be, there is a cost to it so if it wasn't necessary for that particular part they might skip it. It depends how sensitive it is, what the application is, that kind of thing. Manufacturers quickly moved to plastic packages once they became practical.
– user
17 hours ago
1
1
MBA810 is a high power (up to 10W depending on manufacturer) amplifier. The 'wings' aren't ment as ground (although they are connected), but for cooling. They do not go over the IC (like the cap) but below to transfer heat.
– Raffzahn
12 hours ago
MBA810 is a high power (up to 10W depending on manufacturer) amplifier. The 'wings' aren't ment as ground (although they are connected), but for cooling. They do not go over the IC (like the cap) but below to transfer heat.
– Raffzahn
12 hours ago
2
2
Also, the metal cap is never atatched to the die inside, as the upper side of a die contains circuitry and a metal cap will carry a high chance of shortcuting. Heat for dissapation is taken from the lower side. That's why modern CPUs are flip mounted, so heat transfer can be aproved ( also it allows more connections, as now pins may also connect to pads inside the chip, not just aroudn the border.
– Raffzahn
12 hours ago
Also, the metal cap is never atatched to the die inside, as the upper side of a die contains circuitry and a metal cap will carry a high chance of shortcuting. Heat for dissapation is taken from the lower side. That's why modern CPUs are flip mounted, so heat transfer can be aproved ( also it allows more connections, as now pins may also connect to pads inside the chip, not just aroudn the border.
– Raffzahn
12 hours ago
|
show 8 more comments
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